The MyotonPro is a portable device for measuring biomechanical and viscoelastic properties in superficial soft tissues. The aims of this study are firstly to validate the MyotonPro compared to a reliable gold-standard frame and secondly to observe the influence of MyotonPro measurement on the total wrist viscoelasticity.Three silicone polymers with different elastic properties were assessed with the MyotonPro and with a reference rheometer . Then, a free oscillations method was used to measure the passive elastic and viscous stiffness of the wrist and compared to MyotonPro forearm measurements.p = 0.001), decrement (p < 0.001), and relaxation (p = 0.008) parameters for measuring the elastic stiffness (k) of the three polymers. The MyotonPro parameters demonstrated excellent reliability on the forearm. Proximal and distal anterior myofascial measurements of the MyotonPro were moderately correlated to the elastic stiffness  of the wrist while the postero-distal myofascial tissues of the forearm demonstrated a moderate correlation with the viscous stiffness of the wrist .A one-way ANOVA demonstrated the validity of the MyotonPro's stiffness (The MyotonPro is a valid device for measuring elastic stiffness as well as a portable, affordable, and easy-to-use tool for quantifying the biomechanical properties and viscoelasticity of myofascial tissue in healthy subjects. In biomechanics, we use the term “elastic stiffness” to define the “k”  is a non-invasive hand-held, affordable, and easy-to-use myotonometer device aimed at recording the biomechanical and viscoelastic stiffness of myofascial tissues  to assess the validity of the five parameters measured by the MyotonPro compared to an accurate and reliable testing machine tool, a tribometer, which assesses biomechanical properties using silicone polymers; and (ii) to establish the relationship between forearm myofascial tissue, as measured by the MyotonPro, and its correlation to ES and VS of the wrist in healthy young adults, as measured by the EOD.This observational study was performed by using two standard reference systems, a tribometer and the EOD. The accuracy of the five MyotonPro parameters in assessing ES was evaluated on three different polymer surfaces and was compared to the tribometer assessment. The relationship between the passive stiffness of the wrist as assessed by the EOD and the measured stiffness of posterior and anterior, distal and proximal myofascial tissues of the forearm as assessed by the MyotonPro, was evaluated on healthy young volunteers. This study received the approval of the local ethics committee  from the Université Catholique de Louvain  and was performed in accordance with the principles of the Declaration of Helsinki. All participants provided written informed consent.The MyotonPro produces a series of damped oscillations induced by a single external mechanical impulse. The probe of the MyotonPro was placed perpendicularly to the assessed structure and, with a pre-force of 0.18 N, a quick mechanical impulse of 0.4 N was released for 15 ms. The total force applied to the structure was 0.58 N. Following the single external mechanical impulse, free oscillations were recorded for 400 ms. Then, the device needed 10 ms for processing raw signals and five more to compute all the parameters. The sequence was looped five times for a total duration of 2.15 s. The mean value of the five sequences corresponds to one assessment allowing the calculation of five parameters: frequency, stiffness, decrement, relaxation time, and creep. Frequency (F) corresponds to the oscillation frequency and represents either the tonus of the muscle or the state of tension if the muscle is contracted:Stiffness (S) should represent the k of the structure:l = displacement. The decrement (D) is described as the logarithmic decrement of acceleration between the first and second cycle. It represents the loss of energy and is described as the elasticity of the system:where a = acceleration of the probe, m = the mass of the probe and 1 and a3 are the maximal accelerations of the first and second cycles, respectively. A decrement value of 0 would represent a perfect elasticity with no loss of elastic energy (where ac energy . Relaxatc energy . As regac energy . The mor−1) to verify the k, which was independent of speed, for each polymer. The k of each polymer was calculated as the slope of the vertical force  over the vertical displacement (simultaneously recorded). All measurements were taken in the middle of the top of the polymers, which was marked with an indelible dot in order to standardize all measurements at the same testing spot. MyotonPro measurements were assessed twice on each polymer and compared to the k of each polymer.The ES of the polymers was assessed using a universal tribometer mod (UMT-3MT) equipped with a testing block, s/n T45185 . Polymers  were creThe EOD generated sinusoidal rotatory movements to assess the viscoelasticity of the wrist Rack, . The EODThe MyotonPro was applied at four different points of the dominant forearm. Two lines were drawn from both medial and lateral epicondyles of the humerus to the radial styloid to delimit the four measurement sites. The intersection of these lines at the most prominent part of the forearm represented the first site, on the palmar side, the proximal flexor (PF), and on the dorsal side, the second site, the proximal extensor (PE). The middle of the line between the PF and the radial styloid and the PE and the radial styloid corresponded to the third and fourth sites, respectively the distal flexor (DF) and distal extensor (DE), see Concerning the reliability study, a sample of convenience of 30 healthy participants were assessed twice by the same investigator. Then the wrist stiffness was assessed using both the MyotonPro and the electromechanical oscillation device (EOD) in 52 healthy participants. The sample size is based on the calculation that a random sample of 44 subjects produces a two-sided 90% confidence interval with a width of 0.099 when the estimated intraclass correlation is 0.900. Participants were included if they were between 18 and 30 years old, presented no musculoskeletal disorders of the upper limb and had not engaged in any physical activity within the 24 h prior to the experience. Any participants that suffer from any musculoskeletal injuries or pain, neurological disorders or underwent any type of surgery on the upper limb were systematically excluded. The participants were recruited from the university and surroundings areas  and received no financial compensation.Statistical analysis was performed using MedCalc Statistical Software version 16.4.3 .k parameters (tribometer) and MyotonPro's parameters . A post-hoc analysis was performed using the Holm-Sidak method. Measurements between the three polymers were also expressed in per cent. Furthermore, spearman correlation was performed in order to assess any correlation between Tribometer and MyotonPro values.A One-Way ANOVA was performed in order to test the effect of three different polymer densities on The reliability assessment was executed with all the measurement location, i.e., PF, DF, PE, and DE. To determine the Intraclass correlation coefficient, a two-way mixed model with absolute agreement was performed. Furthermore, standard error of the mean (SEM) and minimal detectable change (MDC) were calculated. In order to compare EOD and MyotonPro measurements in healthy subjects, we normalized all parameters as the units of those parameters were different and could not be compared without standardization. More precisely, we processed all parameters following this equation:x represents the parameter of interest. We performed a Passing & Bablok linear regression  with polymer B = 1.436 ± 0.024, C = 2.42 ± 0.036, and A = 2.732 ± 0.021 Nm−1. MyotonPro statistical results showed significant differences between polymers for stiffness , the decrement  and relaxation time . For those three parameters, post-hoc analysis (holm-sidak) showed that all parameters were different between all polymers. Frequency  and Creep  did not demonstrate any significant difference between polymers.Tribometer measurements demonstrated significant differences between the three polymers  .The reliability assessment was performed on 30 healthy participants . The ICC were excellent for all parameters with the exception of decrement, who demonstrated moderate reliability .p < 0.05) correlated to ES. As for VS, only the stiffness and relaxation in the PF were significantly correlated (p = 0.03 and p = 0.04). Finally, the frequency, stiffness, relaxation, and creep of the DE were significantly (p < 0.05) correlated to VS.Of the 52 participants, all were included in the study. There were 31 men and 21 women . With the exception of the decrement of the DF, PE, and DE, no systematic differences were found between the MyotonPro's parameters and ES values . Likewisk could be validly assessed by the stiffness parameter. Secondly, we demonstrated an excellent reliability to all MyotonPro parameters with the exception of D who demonstrated a moderate reliability. Finally, we assessed the influence of the biomechanical and viscoelastic properties of the forearm myofascial tissues measured by the MyotonPro on the passive stiffness of the wrist joint tested with the EOD. We observed a small correlation between the anterior forearm tissue for F, S, R, and C and the ES of the wrist. Also, a small correlation between the distal posterior tissue and the proximal and anterior tissue of the forearm F, S, R, and C was found in regard to the VS.The first aim of this study was to assess the validity of the five MyotonPro parameters in regard to the ES. We used silicone polymers with different stiffness and compared the gold standard, i.e., the tribometer, with the MyotonPro measurements. We found that k). Another study found that stiffness measured with the MyotonPro was highly correlated (r2 = 0.96) with Young's modulus of a gel-based polymer, calculated with a compression test of 100 N at a velocity of 20 mm/min (Dougherty et al., k measurements. The stiffer a structure is, the more acceleration it will induce on the MyotonPro's probe, increasing the stiffness parameter. Likewise, the less stiff it is, the more energy it will release between two oscillation peaks, decreasing the decrement value, and thus increasing the elasticity. We also observed that relaxation time was related to elastic stiffness. Conversely, we could not confirm that frequency and creep parameters were relevant in assessing passive elastic stiffness. This might be due to a lack of validity among those parameters.To the best of our knowledge, this is the first study that compared the five MyotonPro parameters to an accurate and valid device to measure polymer elasticity. Sohirad et al.  previousin vivo study compared the MyotonPro parameters to ultrasound shear wave elastography in myofascial tissue (Kelly et al., Furthermore, an This is the first study to investigate the local biomechanical and viscoelastic properties of the forearm myofascial tissue and its relationship with the passive stiffness of the wrist. It is well-known that the passive stiffness of the wrist is multifactorial Riemann, . The wriZonnino and Sergi  demonstrin vivo measurements of myofascial tissue's viscoelastic properties. Unlike other, more accurate devices such as magnetic resonance elastography (Chakouch et al., Based on our results, the MyotonPro revealed itself to be a suitable device for performing Our study confirmed some underlying questions that were not completely answered in regard to MyotonPro assessment. The stiffness parameter is mostly related to passive elastic stiffness. In the neurological field, several authors have studied the usefulness of the MyotonPro in the quantification of spasticity in stroke patients (Fröhlich-Zwahlen et al., Quantifying and following passive musculoarticular stiffness in myofascial tissues and joints is a growing field of interest among biomechanics specialists, coaches, researchers and clinicians with a view to better understanding movement and its intrinsic properties. This could enhance the validation of therapeutic approaches or sport performance issues (Blackburn et al., This study presented several limitations. Firstly, the stiffness MyotonPro parameters could be confirm in a silicon polymer but a perfect comparison with myofascial tissues should be taken with caution. Secondly, despite showing excellent relative and absolute reliability in the literature, the MyotonPro showed some variability depending on the muscle tested (Agyapong-Badu et al., The stiffness and decrement parameters measured with the MyotonPro technology are valid and demonstrated accuracy in identifying materials with different elastic stiffness. Furthermore, the MyotonPro frequency, stiffness relaxation time and creep of the forearm showed small but significant correlations with passive elastic and viscous stiffness of the wrist. More particularly, the proximal and distal anterior myofascial tissues of the forearm showed a small relationship with the elastic stiffness of the wrist while the distal tissue of the posterior side of the forearm demonstrated a relationship with the viscous stiffness of the wrist.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by Comité d'Ethique Hospitalo-Facultaire. The patients/participants provided their written informed consent to participate in this study.AN: conceptualization, methodology, validation, formal analysis, investigation, writing—original draft, and visualization. CD: conceptualization, methodology, formal analysis, writing—review and editing, and project administration. PF: resources and writing—review and editing. CS: investigation and writing—review and editing. PM: conceptualization, methodology, investigation, writing—review and editing, and supervision. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


With improved longevity and changes in family structure, grandparents are key resources in providing care for grandchildren. However, mixed findings indicate that multiple role engagement may enhance well-being or bring demands on grandparents raising grandchildren. Little is known about how the intensity of grandparent caregiving is associated with their well-being in different family contexts . This systematic review examines the association between the intensity of grandparent caregiving and their well-being. Peer-reviewed articles published after 1990 were identified in five electronic databases. A keyword search was performed for keywords associated with: (a) grandparent caregivers raising grandchildren, and (2) well-being . Only quantitative studies were included. Fifty-six articles from 28 countries/regions were included. Findings suggested that the well-being of grandparents is optimal when they provide caregiving of moderate intensity, with optimal amounts varying across sociocultural contexts. In Europe and Australia, providing supplementary care seems beneficial for grandparents’ well-being, especially supporting dual-earner families. In Asia, economic resources buffer the adverse effect of primary care on grandparents’ well-being. In the U.S., findings vary across ethnicity/race. White grandparents enjoy health benefits providing supplementary care with support from adult children. However, Hispanic grandparent caregivers in multigenerational households have better well-being than those in skipped-generation households, whereas Black custodial caregivers have better well-being than supplemental caregivers. Collectively, the intensity of grandparent caregiving and well-being is complicated by their roles in the family and cultural differences. This systematic review calls for culturally-tailored family interventions.


The coronavirus disease 2019 (COVID-19) pandemic pushes people looking for shopping alternatives, seeking to avoid handling cash in favor of a safe and quick mobile payment. At this juncture, this paper examines the determinants of the adoption of mobile payment services among small and medium enterprises (SMEs) in China. The study proposes four-dimensional factors  based on the literature review findings to understand the challenges of adopting mobile payment. A questionnaire is designed to solicit information from the participants. The findings reveal that business factors, technological competencies of SMEs in China, and the environment positively influence mobile payment adoption. Consumer intention has almost no influence on the adoption of mobile payment. Potential implications for the COVID-19 era are also discussed. The use of mobile devices to provide financial services is widely accepted in advanced countries. It affects communication culture and greatly impacts most commercial and non-commercial systems, including financial activities . Many reChina has the leading mobile payment infrastructure. The mobile payment usage rate globally takes the first position for 3 years by 2020, about 805 million users, occupying 85.7% of the internet users .China's customers' usage rate is not much seen in SMEs . To enhaThis study aims to examine key factors that hinder the adoption of mobile payment services among SMEs and compare and contrast the mobile payment initiative in China to a technologically advanced country, China. We also offer both practical and theoretical implications for SMEs for the coronavirus disease 2019 (COVID-19) pandemic. This study also offers several suggestions to SMEs in China, government institutions, and agencies. At this stage, policymakers and management of companies or institutions using mobile payment should make strategic decisions to combat the COVID-19 pandemic's future challenges. Given that China has the largest e-commerce and mobile payment, China's startup initiative can also consider the mobile payment demand's potential determinants.Literature Review and Theoretical Framework provides a brief literature review and sets the theoretical framework. Basic Features of Data and Findings explains the survey data details, provides basic features of the collected data, and discusses the empirical findings. Conclusion with Implications concludes the paper by discussing potential implications.The rest of the paper is organized as follows. A new paradigm has emerged under the mobile name payment (M-payment). Mallat  defines Mobile payment is also important for SMEs, but they can be defined according to different criteria in the various sectors: manufacturing, construction, and quarrying and mining sectors. For the retailing, miscellaneous, motor trades, and wholesale trades sectors, the sales turnover criterion is used. Whereas, the road transport sector uses several vehicles, the catering sector is based on ownership. In China, the definition of an SME is complex. It depends on a series of variables such as the industry it belongs to, its operating cost, its total assets, and its number of employees. SMEs constitute an overwhelming majority of the enterprises in China. They are the main part of economic development, as they represent 99.6% of China's companies, offer more than 80% of the job positions, and hold more than 70% of the patents .Mobile payment system is becoming a leading payment method in developed economies  and deveThis paper aims to fill in the empirical literature gap by examining mobile payment determinants in China. Our novelty of the research is that we provided a survey in 2020, which captures the COVID-19 era. Therefore, our results may be interesting due to the changing pattern of the country's payment habits.The study proposes four-dimensional factors based on the literature review findings to understand the challenges of adopting mobile payment. The main factors are institutions, technology, consumers' intentions, and business unit or SMEs. These four variables define the critical path for analysis, and organizations need to consider them when adopting a mobile payment system.The institution that could interplay in the adoption of mobile payment includes banks or financial corporations, internet service providers, telecommunication networks, trading partners, software applications, and government support. The extended unified theory of acceptance and use of technology (UTAUT2) as a basic model to accomplish the objectives . BesidesMeasures with proven reliability and validity are applied to operationalize the variables of the research model. The items are rated on a 5-point Likert scale, ranging from “strongly disagree” to “strongly agree” see . Table 2Based on the above analysis, four hypotheses are given as the following:H1: Business factors have a positive influence on the adoption intention.H2: Technological competence has a positive influence on the adoption intention.H3: Environment has a positive influence on the adoption intention.H4: Consumer intention has a positive influence on the adoption intention.Many review studies have considered the inclusion and exclusion criteria so far irrespective of research fields . The resUsers of mobile payments and businesses were invited to participate in the study. The businesses include delivery agencies, malls, KFC, McDonald's, etc. Generally, the study obtains information from 90 respondents in China and 90 respondents in other Chinese regions  for the second set.Data are collected by conducting a field survey questionnaire from participants. The questionnaire has five sections: background information of respondents, institutional or external factors, technological factors, consumer behaviors, and business unit analysis. Two sets of questionnaires are prepared in English and Chinese. Before the questionnaire is administered, it is screened. A pilot test is conducted by sending the questionnaire to five friends to assess flexibility, grammatical errors, and appropriateness. Afterward, the questionnaire is reviewed and arranged to devoid of unethical issues.The data are taken using the WeChat survey application. The questionnaires are filled in the app with due diligence. The following settings are done to ensure high reliability and validity of the data:  the app After designing the online questionnaire and cross-checking everything, it was posted in WeChat groups of business-oriented background. Clear instruction and confidentiality information accompanied the post. The first set of questions are administered to Chinese people only. This survey lasts for 2 weeks, and a total of 180 responses are received. After 3 days, the second part or set of questions is administered. The paper analyzes 180 responses for the second questionnaire analysis. Online data is obtained from the WeChat survey App.According to the research questionnaire, the reliability and validity of the primary structure data of the respondents' background information are analyzed. The respondents' background information is gender, age range, educational qualifications, type of business engagement, and working years.Educational level of staff and owners of small business contributes to M-payment adoption. The respondents' sector of business engagement is shown in The main construct variables affecting mobile payment adoption by SMEs are business factors, technological competence, environment, and consumer intention. The reliability and validity of the scale are analyzed using the valid questionnaire data collected. The reliability and validity of the information of each measurement scale are calculated as shown in It can be seen from The average value, standard deviation, and correlation coefficient between each measured variable are calculated as shown in Business factors, technological competence, environment, and consumer intentions are significantly and positively correlated, indicating that they are all factors affecting adoption. Business factors is significantly positively correlated with the technological competence, environment and customer intention. The above provides the necessary preconditions for analyzing the relationship between the variable.2 = 880.889. This test and the Cronbach alpha reliability test validate the data for all further analysis  and Bartlett is performed based on SPSS. KMO test is a measure of how suited the data are for analysis. The test measures the sampling adequacy for the variables in the model. KMO sampling adequacy is 0.824, which is meritorious. Bartlett's test of sphericity is a <0.05 (Sig. 000). The chi-square results are significant χysis see .This article divides the factors that influence mobile payment adoption challenges among Chinese SMEs into four main categories to investigate how each field and some variables affect SMEs carefully. This analysis covers factors that influence SMEs in adopting a mobile payment service system. It includes cost of adoption, employees' education level, business types, mobile payment readiness, and technology competency , 23.The business or SMEs' characteristics that effectively hinder the business idea of accepting mobile payment service in China are revealed and illustrated in SMEs that have implemented mobile payment system and others that have the idea to practice cannot swerve from technological issues. A survey is conducted to analyze which technological issues affect the Chinese SMEs' attempt to adopt mobile payment see .The external factors are challenges of other technology and own business limitations that hinder mobile payment adoption. These factors are sometimes beyond the SMEs' control and need government or industrial interventions to facilitate implementations.The author investigated many consumer intentions factors, and the respondents reacted in different views. The result is tabulated in This paper uses Mplus7.0 to perform path analysis and hypothesis testing. According to the above test procedure, a relationship model is established between business factors, technological competence, environment, consumer intention and adoption intention see . The tesp = 0.000), assuming H1 is verified. Technological competence significantly influences adoption intention , indicating that the technological competence predicts adoption intention, assuming H2 is verified. Environment also influences adoption intention , indicating that environment is also a key factor influencing the adoption intention, then H3 is verified. Besides, customer intention may have no influence on adoption intention , then H4 is not verified. Business factors, technological competence, and environment positively influence mobile payment's adoption intention, but the SMEs' customer intention does not influence the adoption intention  = 0.000, the model fits well. As can be seen from ntention .The COVID-19 pandemic is expected to have a significant effect on the payment card market. Contactless payment is tagged as a more hygienic and safer way of making payments . This isThe questionnaire results reveal important observations and emphasize that technological factors impede SMEs in mobile payment adoption. The most strongly agreed item is “network connection among payment partners.” Another challenge is the poor and slow internet connectivity; moreover, reliable software applications, technological level of payment facilities, and compatibility of payment facilities are available.Some of the main external factors that affect the adoption of mobile payment systems by China small- and medium-sized enterprises revealed by this study are ICT infrastructure in China and cooperation from telecom providers and banks. Most banks cannot secure and trust effective transactions and network connectivity challenges for mobile payment to be perfect. The external environment factors do not facilitate mobile payment and are not ready due to the large technological and network gap. The basic infrastructure to incorporate all the mobile payment partners seems too expensive, thereby discouraging China's payment system.We investigated many consumer intentions factors, and the respondents reacted in different views. The most strongly agreed factor from the respondents is “perceived trust and security.” With mobile, internet, and bank fraud in Chinese community, consumers find it difficult to believe in the mobile payment system. However, the m-payment system could be successful depending on the relative advantage over cash payment. According to the technology acceptance model (TAM) model, it suggests that perceived usefulness and ease of use are the determinants of users' willingness to accept and use systems. This evidence implies that consumers' perceived usefulness of mobile payment over cash shows a positive emotional enjoyment and will be accepted if SMEs implement mobile payment adoption.Based on the study's findings, we recommend the following for SMEs management, owners, government, and other mobile payment partners. In technology, internet, and network connections, the national communication authority should quickly find reliable measures to offer quality internet access and good network coverage connection in collaboration with the private network providers. China should also embark on ICT infrastructure to facilitate a mobile payment system. Management of SMEs or business units should train their staff to acquire more relevant mobile payment system knowledge. In addition, we suggest that SMEs seek credit to facilitate the cost of mobile payment adoption and upgrade their technological equipment on business factors. Future studies can focus on the post-COVID-19 era for analyzing the determinants of mobile payment adoption in other developing countries.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by The survey in the study has been approved by the ethics committee of the Nanjing Institute of Technology. The patients/participants provided their written informed consent to participate in this study.The author confirms being the sole contributor of this work and has approved it for publication.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Zirconia nanofiber mats containing filaments with the average diameter of less than 100 nm were fabricated. It is found that the hardness and Young’s modulus of the mats are sensitive to the microstructure, phase composition and average diameter of the zirconia nanofibers. The hardness and Young’s modulus of the prepared zirconia nanofiber mats vary from 0.86 to 1.67 MPa and from 133 to 362 MPa, respectively, wherein an increase in hardness is accompanied by the rise in Young’s modulus. Among all the variety of nanofibers only ceramic ones possess increased thermal and chemical resistance ,2. Elect2) and high-temperature tetragonal (t-ZrO2) and cubic (c-ZrO2) [2 and c-ZrO2 phases can exist at room temperature if the stabilizer is introduced into pure zirconia in the required amounts. Yttria is one of metal oxides commonly used as a stabilizer. It is well known that the mechanical characteristics of bulk zirconia ceramics can be significantly improved by adding 3 mol% Y2O3 to pure zirconia to obtain tetragonal zirconia polycrystalline ceramics [Zirconia and its precursors are widely used to obtain different advanced ceramic materials . Pure zi(c-ZrO2) . Howeverceramics .Zirconia nanofiber mats are ceramic nanofiber mats with a wide range of possible applications as scaffolds for solid oxide fuel cells cathodes ,6, separHowever, the functional properties of mats depend on the diameter, grain structure, phase composition and porosity of the nanofiber components. There are several ways to control the microstructure and phase composition of zirconia nanofibers via varying the calcination temperature , dopant For any zirconia nanofiber mat application the mechanical characteristics are important. Tensile testing is usually performed to obtain data on tensile stress, ultimate strain and Young’s modulus of the ceramic nanofiber mats ,23,24. NThe aim of this work is to study the effect of zirconia nanofibers microstructure and phase composition on the mechanical characteristics of their mats, such as hardness and Young’s modulus, using the nanoindentation method. To reveal the relationship between the morphology of zirconia nanofibers and the mechanical properties of the mats made from them is important for any practical use of the latter, and also provides prerequisites for fabricating nanofibrous materials with the required structure and functional properties.The mats of zirconia nanofibers with the average diameter of less than 100 nm were prepared and characterized according to the scheme shown in 2O3-ZrO2 nanofibers. Composite solutions with ZrAA/PAN mass ratios of 0.1:1, 0.2:1 and 0.3:1 were fabricated.Polyacrylonitrile  was dissolved in N,N-dimethylformamide  under magnetic stirring for 2 h at 50 °C to prepare 10 wt.% polymer solution. Zirconium acetylacetonate  and yttrium nitrate hexahydrate  were added into the prepared polymer solution and stirred at 80 °C until the solution became transparent. The amount of yttrium nitrate hexahydrate was such to obtain 3 mol% YThe prepared composite solutions were poured into a 10 mL plastic syringe and then electrospun through a 23 G blunt tip needle upon the rectangular frame collector made of copper wire placed in a NANON-01A electrospinning machine . The fibers were collected as non-woven mats. The accelerating voltage of 18 kV, the distance between the needle tip and the collector of 15 cm and a feeding rate of 1 mL/h were chosen to fabricate smooth and bead-free composite fibers.The electrospun mats were calcined at different temperatures in air atmosphere between lightweight alumina plates with a smooth surface to prevent the mats wrinkling. Calcination was carried out in several stages in accordance with the performed thermogravimetric (TG) analysis and differential thermal (DT) analysis: heating to 320 °C with a heating rate of 1 °C/min, holding at 320 °C for 1 h, further heating to 600 °C with the same heating rate and holding at 600 °C for 1 h and finally heating to 700, 900 or 1200 °C with a heating rate of 5 °C/min and holding at the target temperature for 1 h.The TG analysis and DT analysis were performed on the thermal analyzer EXSTAR TG/DTA7200  in air atmosphere with a heating rate of 10 °C/min.The microstructure and diameter of the fibers were examined with a Merlin scanning electron microscope . The XRD patterns were registered in the 2θ range 20–80° by a D2 Phaser X-ray diffractometer  using CuKα1 monochromatic radiation and analyzed by means of the PDF-2 Diffraction Database File compiled by the International Centre for Diffraction. The phase content was determined from the XRD patterns by the Rietveld method using the TOPAS software (Bruker AXS) and the average grain size was also calculated in the TOPAS software (Bruker AXS) using the Scherrer equation. SEM and XRD measurements were carried out at room temperature. The specific surface area and the pore volume of the fibers were measured by nitrogen adsorption at −196 °C with a gas sorption analyzer Autosorb iQ-C . The specific surface area was determined using Brunauer-Emmett-Teller method in a relative pressure range of 0.05–0.35. The pore volume was determined from the amount of nitrogen adsorbed at the relative pressure of 0.99.−1 was kept during all the tests. The load-displacement curves were obtained under peak load of 5 mN. Peak load was held for 10 s to stabilize the possible creep in the mat. At the end of unloading a hold of 15 s was provided to correct the thermal drift. The Poisson’s ratio was about 0.25. Young’s modulus (E) and hardness (H) of the samples were calculated from the load-displacement curves using the Oliver-Pharr method [2O3-ZrO2 ceramic pellets with Young’s modulus of about 220 GPa and hardness of about 14 GPa. The thickness of the tested samples was at least 50 μm.Nanoindentation measurements were carried out by a TI-950 nanotriboindenter (Bruker AXS) at room temperature using a stabilized zirconia spherical indenter with a radius of curvature of 250 μm. A constant strain rate of 0.05 sr method . The tes2O3–ZrO2 nanofibers calcined at 700 °C are cylindrical in shape, with a smooth surface , 17.7 nm (0.2:1) and 18 nm (0.3:1). A slight decrease in the average t-ZrO2 grain size due to reduced ZrAA/PAN mass ratio may be associated with a decrease in the contact surface between the grains due to a decrease in the resulting ceramic fibers diameter that negatively affects the diffusion process. Previously, a similar effect was observed for zirconia nanofibers made of composite filaments containing zirconium oxychloride and poly(ethylene oxide) [2O3-ZrO2 nanofibers fabricated from the composite filaments with ZrAA/PAN mass ratios of 0.3:1, 0.2:1 and 0.1:1.It is revealed that the decrease in ZrAA/PAN mass ratio has no effect on the phase composition of the resulting 3 mol% Ynofibers . Poorly e oxide) . Close v2 peaks appear . This allows concluding that a small amount of yttria acts as an inhibitor of ZrO2 grain growth in nanofibers similarly to Y2O3 -stabilized zirconia bulk ceramics [The main characteristic peaks of m-ZrO0 °C. In  it was rain size . The m-Z 1170 °C . A dopan 1170 °C . The t-Zain size . It explceramics .2O3-ZrO2 nanofiber mats calcined at different temperatures. It can be seen from High calcination temperature leads to formation of junctions between nanofibers at the cross-points due to sintering, which negatively affects the nanofibers freedom of movement. As a result, the mat loses flexibility and its Young’s modulus increases. Besides, the mat becomes harder and more brittle. Low calcination temperature is insufficient for nanofibers sintering at their cross-points as well as for zirconia grains sintering inside the filaments to form strong contacts. Thus, we suppose that there are no other bonds than the Van der Waals forces providing free movement of the nanofibers and the grains inside them. Therefore, zirconia nanofibrous mats calcined at low temperatures are more flexible than ones calcined at elevated temperatures. Flexible materials are known to be characterized by reduced Young’s modulus . Previou2O3-ZrO2 nanofibers produced at 700 and 900 °C have close average diameter values and differ in their average grain size. The smaller size provides a stronger connection between the grains due to a larger contact area, which hinders their free movement. The nanofibers become stiffer andtheir Young’s modulus increases, respectively. As a result, nanofibrous mat Young’s modulus increases too. The 3 mol% Y2O3-ZrO2 nanofibers prepared at 1100 °C have larger grains than filaments prepared at 700 and 900 °C. However, the connection between grains is stronger due to necks, which are formed at elevated calcination temperatures. Besides, sintering provides interfiber junctions at the cross-points as well. It explains the highest values of hardness and Young’s modulus for the 3 mol% Y2O3-ZrO2 nanofiber mat fabricated at 1100 °C.The 3 mol% Y2O3-ZrO2 nanofiber mats is three orders of magnitude lower than that of bulk 3 mol% Y2O3-ZrO2 ceramics [2O3-ZrO2 nanofibers with the average diameter of 530 ± 120 nm prepared using zirconium n-propoxide, yttrium acetate hexahydrate and polyvinylpyrrolidone were characterized by Young’s modulus of 1.11 ± 0.24 MPa obtained by means of microindentation. Different Young’s modulus values of the mats presented in this article and those fabricated in [Young’s modulus of the fabricated 3 mol% Yceramics . This meceramics  mats of cated in  can be a2O3-ZrO2 nanofiber mats prepared at the same temperature from the mats of composite filaments with different ZrAA/PAN mass ratios are presented in The load-displacement curves obtained for 3 mol% Y2O3-ZrO2 nanofibers fabricated from composite filaments with different ZrAA/PAN mass ratios possess identical phase composition and consist of similar-sized zirconia grains, but differ in their average diameter, which increases with the rise in ZrAA/PAN mass ratio. A decrease in the zirconia nanofibers diameter associated with a decrease in ZrAA/PAN mass ratio results in the rise in both hardness and Young’s modulus of zirconia nanofibrous mat  are less than those of the mat of nanofibers mostly comprised of m-ZrO2 . The higher Young’s modulus and hardness of the undoped zirconia nanofiber mat indicate that it is stiffer and more brittle than the 3 mol% Y2O3-ZrO2 nanofiber mat prepared at the same temperature and containing no m-ZrO2. As mentioned above, t-ZrO2 → m-ZrO2 transition occurs if undoped zirconia nanofibers are calcined at 900 °C. Phase transition is accompanied with volume expansion which creates large internal stresses. The latter may induce nanofiber damage. It results in greater fragility of undoped zirconia nanofiber mats compared to stabilized zirconia nanofiber mats. Thus, it can be concluded that the presence of m-ZrO2 in zirconia nanofibers worsens the strength of both zirconia nanofibers themselves and the mats they form. An increase in the calcination temperature leads to the rise in the fragility of individual undoped zirconia nanofibers and their mats, respectively, due to m-ZrO2 content increase. In [Regarding the example of the 3 mol% Yease. In  it has bZirconia nanofiber mats containing filaments with the average diameter of less than 100 nm were fabricated. It is found that the hardness and Young’s modulus of the mats are sensitive to the microstructure, phase composition and average diameter of the zirconia nanofibers. A decrease in the diameter of nanofibers and an increase in the heat treatment temperature leads to an increase in the hardness and Young’s modulus of the mats. The hardness and Young’s modulus of the prepared zirconia nanofiber mats vary from 0.86 to 1.67 MPa and from 133 to 362 MPa, respectively, wherein an increase in hardness is accompanied by the rise in Young’s modulus. The obtained results indicate the possibility of controlling the hardness and Young’s modulus of nonwoven zirconia membranes via varying the calcination temperature and intermediate filament composition.


A polymeric bone implants have a distinctive advantage compared to metal implants due to their degradability in the local bone host. The usage of degradable implant prevents the need for an implant removal surgery especially if they fixated in challenging position such as maxillofacial area. Additionally, this fixation system has been widely applied in fixing maxillofacial fracture in child patients. An ideal degradable implant has a considerable mass degradation rate that proved structural integrity to the healing bone. At this moment, poly(lactic acid) (PLA) or poly(lactic-co-glycolic acid) (PLGA) are the most common materials used as degradable implant. This composition of materials has a degradation rate of more than a year. A long degradation rate increases the long-term biohazard risk for the bone host. Therefore, a faster degradation rate with adequate strength of implant is the focal point of this research. This study tailored the tunable degradability of starch with strength properties of PLA. Blending system of starch and PLA has been reported widely, but none of them were aimed to be utilized as medical implant. Here, various concentrations of sago starch/PLA and Polyethylene glycol (PEG) were composed to meet the requirement of maxillofacial miniplate implant. The implant was realized using an injection molding process to have a six-hole-miniplate with 1.2 mm thick and 34 mm length. The specimens were physiochemically characterized through X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier Transform Infrared spectroscopy. It is found that the microstructure and chemical interactions of the starch/PLA/PEG polymers are correlated with the mechanical characteristics of the blends. Compared to a pure PLA miniplate, the sago starch/PLA/PEG blend shows a 60–80% lower tensile strength and stiffness. However, the flexural strength and elongation break are improved. A degradation study was conducted to observe the mass degradation rate of miniplate for 10 weeks duration. It is found that a maximum concentration of 20% sago starch and 10% of PEG in the PLA blending has promising properties as desired. The blends showed a 100–150% higher degradability rate compared to the pure PLA or a commercial miniplate. The numerical simulation was conducted and confirmed that the miniplate in the mandibular area were shown to be endurable with standard applied loading. The mechanical properties resulted from the experimental work was applied in the Finite Element Analysis to find that our miniplate were in acceptable level. Lastly, the in-vitro test showed that implants are safe to human cell with viability more than 80%. These findings shall support the use of this miniplate in rehabilitating mandibular fractures with faster degradation with acceptance level of mechanical characteristic specifically in case of 4–6 weeks bone union. Degradable implant, Maxillofacial fracture, Fast implant degradation, Pediatric patients, Sago starch/polylactic acid/polyethylene glycol blend, Finite element analysis. The two compounds were mixed in a mixer  at 160 °C at 100 rpm for 10 min. The blend was then mixed with 20% sago starch/PLA (SPLA20) in a ratio of 9:1 with an 8:2 weight fraction. The blending was carried out in an extruder from Haake Rheomix . The temperature was set to 180 °C. The extrudate was then dried, comminuted, and stored in a desiccator for 20 h.2.3The sago starch/PLA/PEG compound was processed at 160 °C in an injection molding machine  with a holding pressure at 500 MPa, cooling time 24 s, and molding temperature of 30 °C. The mold was previously designed to produce a six-hole miniplate that is 1.2 mm thick, 6.1 mm wide, and 34.0 mm long. A three-dimensional model of the miniplate was built using Autodesk Inventor a.Figure 2.4A finite element analysis (FEA) software has an advantage to give better and quick visualization behind a mathematical formula. In the FEA study, the specimen was assumed as an isotropic and compressible neo-Hookean material. These set assumptions might result a deviation between the numerical study and the experimental result. Therefore, a verification step was taken by conducting FEA study to simulate the deformation process of specimen by applying force equivalent in the experimental setup. A grid independence test was also conducted to verify the mesh size that appropriate to our simulation. Initially, a various mesh size was arranged at 0.2 mm–2 mm, which will be selected once the mesh convergence was completed.A 3D model of mandible data was purchased from Synbone AG  in STL format. The data were imported to an Autodesk Inventor 3D modeling software and then modified to create a jawbone split into two parts b. AfterwThe mechanical properties of the miniplate were assigned upon the completion of mechanical characterization of the sago starch/PLA/PEG. The successful scenario of the implants was indicated by the values of peak von Mises stress (PVMS) resulted by the working forces on both superior and inferior plates. The VMS is a theoretical stress at a specific finite element of a material to indicate the resulted forces applied at the element from three different axes. The peak VMS (PVMS) is obtained from the finite element that receives the highest value of VMS in a material. The PVMS below the tensile strength of the composites indicates that the material succeeds to retain the working forces, and vice versa. A complete setup of mechanical properties and boundary setting was detailed in 2.5onset) of the composite.The analysis was performed on a simultaneous thermal analyzer . Thermogravimetric analysis (TGA) was used to describe the thermal stability of the miniplate. Each sample (20 mg) was heated from 25 to 600 °C at a heating rate of 20 °C/min under an argon atmosphere. The mass change data were analyzed to estimate the temperature of the onset of degradation (Tg), cold crystallization temperature (Tcc), and melt temperature peak (Tm). The enthalpy of fusion (ΔHm) and enthalpy of crystallization (ΔHcc) were also gathered from this measurement. The melting properties were acquired during the heating scan, whereas the crystallization properties were acquired during the cooling scan.The thermal transition of the compound was investigated by placing the sample (15–20 mg) on an aluminum pan that was initially heated from 0 to 200 °C at a heating rate of 10 °C/min. Data output determined the glass transition temperature  in the spectral range of 15–27,000 cm2.7c) was calculated using:The microcrystalline structure was determined using X-ray diffraction at room temperature. Samples were characterized using XRD Panalytical Empyrean  at 40 kV and 30 mA with Cu anode radiation at wavelength of 1.5406 Å. The result analyzed using HighScore Plus version 3.0 Standpoint with 2θ between 10° and 80° with a 0.0263°/step scanning rate. Crystallinity degree (X2.8The micromorphology of the miniplate was observed with SEM (FEI Quanta 650) with an acceleration voltage of 7.5 kV. Specimens were prepared under liquid nitrogen and coated with gold before observing the surface fracture. The magnification was arranged at 1,000 times to observe the sago starch blending with PLA and PEG.2.9Five miniplates of each composite was prepared before the mechanical testing, which used an MCT-2150 A&D Company  universal testing machine (UTM) with a maximum force of 500 N at a crosshead speed of 10 mm/min. The tensile test that was based on the ASTM D638 Standard  was perf2.10loss (%) is the average degradation rate, mo is initial weight, and md is final weight. However, the result of the degradation mass was showed as remaining weight which calculated as:The biodegradation test miniplate was performed according to ISO 10993-5 (E): Biological evaluation of medical devices, Part 5: Tests for in vitro cytotoxicity , 55. Min2.11Biocompatibility test of miniplates were conducted using a 3--5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium Cell Proliferation (MTT) Assay Kit from Promega  , 57, 58.Cell viability measurements were carried out at 24, 48 and 36 h after seeding. The previous cell growth medium was discarded and replaced with 450 μl of new medium in each well. A 50 μl of MTS was added, then incubated for 3 h in a 5% CO2 incubator at 37 °C. The medium and MTS were then collected and transferred to 96 well plates (100 μl each with 4 repetitions). The absorbance of the medium and MTS was measured at a wavelength of 490 nm using Multiskan GO spectrophotometer . The cell viability was quantified as the percentage relative of absorbance of the resulting solution compared to the control at 24 h after seeding.Cell suspensions were diluted twofold with a trypan blue solution 0.4% (w/v) . Ten μL of the mixture was placed on a Bright-Line hemocytometer glass , and analyzed by using a light microscope  with 10× magnification. Cells were counted in 25 frames of the hemocytometer according to the manufacturer's recommendations. The percentage of cell viability calculated based on the number of living cells compared to the control.33.1The microstructure of the pure PLA miniplate presented a surface with unidirectional flow resulting from the injection molding process a. The saAt the lower concentration of sago starch (less than 20%), the interaction between the hydroxyl group of the glucose unit in the starch and the carboxyl group of PLA was formed an interface . AccordiBased on the SEM micrograph, it is found that the sago starch did not mix evenly due to differences in hydrophilicity , 26. ThiSignificant changes in the microstructure of the miniplate were observed with the addition of PEG to the PLA matrix a. The PLAn additional compound, PEG, was needed as a plasticizing agent in the sago starch/PLA system to mitigate the phase separation issue. PEG forms a layer around the starch particles, which molecularly increases the interface bond between PLA and sago starch . This inThe micrograph of degraded SPLA20 showed a crack of dispersed starch particles on the PLA matrix after 28 days of degradation. The observation period was chosen due to the rapid growth of host bone during its remodeling in three weeks’ time . This re3.2m) was 161.2 °C. The sago starch DSC curve shows a broad endothermic peak with Tg observed at 61.3 °C. The thermal behaviour of PEG showed a sharp endothermic peak with Tm of 57.7 °C. From the observation, PEG and sago starch addition slightly decreased the thermal transition of material. PEG addition should decrease the Tg of PLA compared to the sago starch, according to Baiardo's report [g lower than pure PLA. It is beneficial for maxillofacial implants since the osteosynthesis devices must be adapted optimally to fit the bone [g to shape the facial contours.The thermal characteristics were determined by DSC and TGA thermograms. DSC is a thermodynamical method for determining the direct heat energy uptake during a controlled increase or decrease in temperature . The ress report . Other rs report , 69. Tabthe bone . While ionset, and sago had the smallest Tonset compared to other materials. It is also confirming that the addition of 20% sago starch decreased Tonset by 33.9 °C, which is a much as 11.5% compared to pure PLA. PEG addition slightly modified the Tonset of the blending, as shown by the PLAP10 specimen. This was also observed for the sago starch/PLA/PEG blending system. We observed 11% and 6% lower Tonset with the addition of 10% and 20% PEG to the sago starch/PLA blend, respectively. It can be concluded that the addition of sago starch had a great influence on the thermal degradation behaviour of PLA, and the decomposition temperatures all shifted to lower temperatures compared to pure PLA. TGA analysis showed that these materials were less thermally stable compared to pure PLA. On the contrary, the addition of PEG only slightly increases the thermal degradation behavior of PLA.TGA analysis is an analytical method that monitors the weight change that occurs as a sample is heated at a constant rate to assess the thermal stability of the material and the fraction of volatile components . Figure 3.3The diffraction patterns indicating the crystallinity phase of PLA, sago starch/PLA, and sago starch/PLA/PEG blends are shown in XRD patterns of sago starch/PLA and sago starch/PLA/PEG phases are also shown. The XRD pattern of PLA/PEG (PLAP10) exhibited small and less sharpness diffraction peak at around 16.4°, whereas the sago starch/PLA (SPLA20) showed small peak at 16.6°. It indicates that sago starch blending increases the crystallinity. The different compositions of blended material sago starch/PLA/PEG also showed different peaks. SPLA20P10 had a small broad diffraction peak at 16.4° while SPLA20P20 had a strong and sharp diffraction peak at 16.8°, 19.3° and 23.4°. This diffraction angle is indicated that increasing the PEG concentration in the sago starch/PLA mixture shifts the crystallinity peak of the compound.c) using The ratio between the area related to the crystalline phase and the overall area under the XRD curve was used to compute the crystallinity degree  and significantly decreased the glass transition temperature (Tg). We think that the PEG contributed to increasing the crystallinity of the PLA blend with sago starch. This increasing crystallinity was also confirmed by FT-IR scanning of sago starch/PLA. Note that pure PLA was found to have a more amorphous structure [The thermal characterization confirmed that the addition of PEG significantly increased the melting temperature  spectroscopy, as shown in −1 for C=O stretching peak of ester group appeared. It is also appeared for mixing sago starch and PLA in PLAP20. The peak O–H which corresponds to hydroxyl group in sago starch does not appear in the blending. PEG/PLA, sago starch/PLA, and sago starch/PEG/PLA shows similar absorption peak as pure PLA. This means that there is no effect on the addition of sago starch on PLA blending. This ensures that the blend does not form new bonds or intense chemical interactions within the mixture, which consistent with previous result [As shown in s result .3.5Miniplate specimens were subjected to tensile and bending tests to determine tensile strength, tensile modulus, elongation break, flexural stiffness, and flexural strength. The results are summarized in The bending test revealed a similar behavior, with the flexural strength of sago starch/PLA decreasing compared to the pure PLA b. The adA mechanical measurement was also recorded on a commercial product with a similar design, Inion® . This product is mainly based on a mixture of PLA/PLGA with a weight percent of 85:15 . The tenThe addition of PEG was the main contributor to the change in mechanical characteristics. When the PLA matrix deforms in the presence of pressure and increased shear forces during the injection molding process, the PEG interface forms effectively around the starch particles. Thus, the addition of a PEG compatibilizer can prevent the formation of brittle fractures and significantly increase the elongation at break of the miniplate.The mechanical testing confirmed the poor interfacial interaction between starch and PLA, as the tensile strength was consistently reduced with the addition of higher concentrations of sago starch. Sago starch is hydrophilic, whereas PLA has hydrophobic properties . The add3.6The mass degradation of the sago starch/PLA blend in the PBS environment is depicted in nd week and reached a remaining of 25% remaining strength at its 6th week.The degradation rate of the miniplate specimens showed a strong relation with the structural bond between sago starch/PLA and PEG. A higher degradation rate was observed for larger fractions of the hydrophilic part due to the use of sago starch. Generally, the PEG interphase layer will increase the interface between PLA and sago starch. This interface layer was confirmed in the SEM results of the miniplate with PEG content of 10% by weight (SPLA20P10) as shown in th week of immersion time. In this case, the SPLA20P10 found to meet the miniplate requirement in term of strength and degradation rate.The degradation study suggested that to gain a fast degradation, the content of sago starch was the key component. However, the study also showed that the mechanical properties were decreasing with more content of sago content. Therefore, the SPLA20 was selected as the base formulation to be mixed with PLA/PEG compound. Here, the PEG with 10% concentration in the PLA, PLAP10, showed a similar degradation with other PLA/PEG content b. Howeve3.7The effect of starch and PEG composites toward proliferation of human stem cell line was evaluated by using the MTS assays. The PLA miniplate and the sago starch/PLA has a lower viability at around 55 ± 11%, whereas the PLA/PEG and starch/PLA/PEG miniplate has a viability around 60%–70% after 24 h of cell culture a. After The PLA miniplate consistently showed a relatively lowest cell viability, among the group during the 3 days observations. Note that, this relatively lowest cell viability of pure PLA has been studied to be compatible as our previous study . ImportaThe following The biocompatibility study confirmed that the sago starch and PEG blending with PLA have positive result in in 48 h cell culture. A significant difference between the cell viability on the PLA/PEG and sago starch/PLA/PEG miniplates were not found. On the other hand, the PLA pure miniplate shows a lower viability value. This finding agreed with the previous finding that starch has a high biocompatible performance . Additio3.8Firstly, the FEA study was verified with the experimental results using the same geometrical and measured mechanical properties. The property was obtained from the material testing results . A forceFEA was performed using a static structural mechanics module after assembling the mandible model and two miniplates, as shown in Briefly, the FEA study provide a failure criterion whenever the resulted stress exceeds a certain critical value. In this case, the miniplate is said to begin to be compromised when the von Mises stress reaches a critical value known as yield strength. Here, the von Mises stress is used to predicting the yield level of the material under the loading conditions of simple uniaxial tensile test results.The peak von Mises stress (PVMS) values were 23.9 MPa and 18.1 MPa for the superior and inferior plates, respectively. The PVMS result of the inferior miniplate indicated that the working force was still tolerable by the material since the PVMS values to the superior and inferior plates were lower than the tensile stress of the blended system (25.63 ± 2.2 MPa).4This paper introduced a sago starch/PLA/PEG blend system that later served as medical degradable implant. The implant was aimed to address a mandibular fracture that required a faster degradation rate compared to available product. Ideally, a Moreover, the implant must withstand a standard load as detailed in the numerical study. Combining a fast degradability of sago starch and mechanical strength of PLA polymer was the basic idea that driven this study. Our findings agree with those of similar report that the sago starch/PLA blend had a lower tensile strength and modulus of elasticity with increasing concentration of starch. On the other hand, the PEG that added brought a higher elongation break and flexural strength that compensated the lowering of mechanical strength. Therefore, the numerical study showed that the blend formulation of 20% sago starch/PLA with 10% of PEG/PLA performed at an acceptance level of mechanical characteristics. The degradation rate of this blend system also shows a 20% higher rate compared to the available product that confirmed in 10 weeks observation. The remaining strength was achieved at around 70% of its initial value at week 4 to week 6 as expected. It was reported that the bone union was evident in that period so that the bone regains the strength to withstand the load after operation. Ultimately, the biocompatibility study showed that the sago starch and PEG in PLA compound promoted a better cell viability. This finding showed a promising result in term of its mechanical property and degradation rate in in-vitro setting. A further study shall be needed to explore the application of the miniplate in animal bone modeling.5The work aims to introduce a new bone implant based on bio-based material namely sago starch that could contribute the degradability feature for pediatric patient with relatively fast bone growth.Y. Whulanza: Conceived and designed the experiments; Analyzed and interpreted the data; Wrote the paper.A. Azadi: Conceived and designed the experiments; Performed the experiments; Wrote the paper.S. Supriadi: Contributed reagents, materials, analysis tools or data.S. F. Rahman: Analyzed and interpreted the data.M. Chalid: Analyzed and interpreted the data; Contributed reagents, materials, analysis tools or data.M. Irsyad: Performed the experiments.M. H. Nadhif: Performed the experiments; Analyzed and interpreted the data; Wrote the paper.P. Kreshanti: Conceived and designed the experiments.LPDP Ministry of Finance Republic of Indonesia under grant Rispro Invitasi 2019 (no. UI SK KEP-52/LPDP/2019).This work was supported by the Data included in article/supp. material/referenced in article.The authors declare no conflict of interest.No additional information is available for this paper.


Facial Plastic Surgerywas founded in the early 1980s by two titans of the facial plastic and reconstructive surgical world—Gene Tardy and Tony Bull. These two friends and giants of the field sought to span the Atlantic and create the first journal solely dedicated to advancing knowledge in facial plastic surgery. The journal would select leaders in the field to serve as guest editors of “themed” issues, who would then commission top surgeons to write “state-of-the-art” review or expert opinion articles within that theme. Led by editors from both sides of the Atlantic and published by Thieme Medical Publishers, the journal sought both authors and an audience international in nature. In recognition of the rapidity with which research in the field was growing,Facial Plastic Surgerybegan accepting free papers on topics important to the facial plastic surgery community in 2010; the journal has published original research from all continents except Antarctica. In this new model,Facial Plastic Surgerynow publishes all accepted articles (commissioned and “unsolicited” papers) online as soon as possible. The editors and publisher have committed to a rapid review of all submissions and e-publication of all articles within 8 weeks of acceptance.Facial Plastic Surgeryis the official journal of the European Academy of Facial Plastic Surgery, and while known to the US facial plastic surgery community, we welcome the opportunity to work more closely with members of the American Academy of Facial Plastic and Reconstructive Surgery (AAFPRS) and the editorial team ofFacial Plastic Surgery & Aesthetic Medicine.The journalArchives of Facial Plastic Surgery21 years ago and then,JAMA Facial Plastic Surgeryunder editor, John Rhee. The journal recently transitioned to the AAFPRS with a new nameFacial Plastic Surgery & Aesthetic Medicineand an impact factor of 3.78. This journal name represents the surgical and nonsurgical diversity of facial plastic surgeons' practices as the official journal of the AAFPRS. The journal is also affiliated with the European Academy of Facial Plastic Surgery, The Australian Academy of Facial Plastic Surgery, and the International Federation of Facial Plastic Surgery Societies. The editorial team, AAFPRS, and new publisher  intend to build upon this rich history as a multispecialty, peer-reviewed journal that seeks to enhance patient outcomes by providing accurate and innovative original research.Facial plastic surgery has become an international specialty with outstanding global contributions. In that spirit, we look forward to a new collaboration with an old friend. Our field is blessed to have two journals with different backgrounds and strengths, unified in a commitment to further the art and science of facial plastic surgery. Wayne Larrabee launchedFacial Plastic Surgeryathttps://www.thieme.in/facial-plastic-surgery-journalandFacial Plastic Surgery & Aesthetic Medicine(http://www.liebertpub.com/fpsam).We look forward to a collegial and productive collaboration between these two journals as our international specialty grows. These two journals have a shared history and commitment to excellence for our readers. We recognize that our specialty of facial plastic surgery will productively grow throughout the world by publishing both rigorous scientific studies and expert opinions, contributing to the consolidation of the knowledge and attitudes of our field. Readers should find both journals online with subscription access to


We investigate the impact of COVID-19 on 42,401 UK SMEs and how government intervention affects their capability to survive the pandemic. The results show that, without governmental mitigation schemes, 59% of UK SMEs report negative earnings and that their residual life is reduced from 164 to 139 days. The analysis shows that government support scheme reduces the number of SMEs with negative earnings to 49% and allows extending the residual life for SMEs with negative earnings to 194 days. In addition, the support scheme reduces the number of jobs at risk in our sample by around 20%. However, our results suggest that weaker firms benefit more than strong ones. Besides, industries that are worst hit by COVID-19 are not those that benefit most from the government support scheme. We ascribe this result to the fact that the schemes do not discriminate between those firms that deserve support and those that do not deserve it. The economic crisis linked to COVID-19 is very different from the last financial crisis (2007–2008) since it does not have a financial origin (bubble-burst cycle); it is the kind of black swan event that took the world economy by complete surprise  they reduce the number of jobs that would have been lost; (2) they reduce the number of SMEs with negative EBITDA; and (3) they extend the life of those SMEs that are burning cash. Thus, at first sight, the results suggest that the policies are successful in protecting the economy. However, our analysis also suggests that the SMEs that benefit the most in terms of extended days of life are those that are weak irrespective of COVID-19 effect. Besides, when we focus on the regional impact, we find that the biggest beneficiary of government intervention is the London area, even if the areas that are facing the greater negative economic impact by COVID-19 are Scotland and Northern Ireland. All in all, our evidence suggests that these two schemes overprotect weak firms and are not able to target industries/areas that are worst hit. We argue that this happens because the interventions are very general and are not able to target those firms that deserve support.The concept of cash reserves (or holdings) can be traced back to Keynes , who sugAs discussed at the outset of this paper, the crisis linked to COVID-19 is mainly the result of the forced shut down of the economies because of the lockdown. This event halted the production and the services provided by many firms so that they were not able to offer their products/services anymore . Besides, those firms that were allowed to maintain their production were adversely affected by the disruption of their supply chains and the constrains linked to the access of inputs. In such a context, firm’s capability to generate cash is essential in order to live and in particular to navigate during the crisis time. When the firm has a positive cash flow, it should be able to maintain the current operations since it generates enough cash to cover all its immediate costs; on the other hand, when the expected cash flow is negative, the SME is implicitly “burning cash”. In this case, the “residual life” of the SME depends on the burning rate that is how rapidly the negative cash flow consumes the cash holdings that the SME can use in order to cover the current excess costs (cash outflow). Actually, SMEs can rely on cash in bank and any other very liquid asset, but also on debtors that are expected to be converted in cash quite soon.In order to explore SMEs’ capability to survive COVID-19, we develop a simple but versatile forecasting model based on the firm EBITDA, in which sales shock and government supports are key inputs. Our model builds on the shock that firms face on their sales and then see how it affects the capability of the firms to generate positive EBITDA. By relying on EBITDA, we follow past research Altman,  that argOrdinary scenario – expected EBITDA based on the past performance and not considering any negative effect linked to COVID-19 shockScenario with the shock on sales at industry level as generated by COVID-19 – Office of National Statistics estimated reduction (ONS 2020)Scenario with the implementation of the UK government policies to support small firms  – and the BBLSWe estimate EBITDA and then the “residual life” of the SME under three different scenarios:Our estimations are based on data up to 2018 in order to rely on a large dataset of 42,401 observations. Then, we re-estimate the three scenarios using 2019 data .We assume the SME-specific relationship between change in sales, change in cost of goods sold (COGS), and change in cost of labour. We work out separate ratios because: (1) COGS and labour-related costs have different sensitivities to sales depending on how the firm runs operations  and (2) the UK governments launched a job specific scheme – the CJRS – that covers the cost of furloughed employees during the crisis period. Thus, in order to appreciate the real impact of this scheme, it is mandatory to keep the evolution of labour-related costs in isolation.k, operating in the industry i. Thus, the sensitivity is given by:k in industry i in year t. In a similar way, we work out the SMEs’ specific labour sensitivity k operating in the industry i as:S, t, k, and i are defined as above, and First, we estimate the sensitivity S, t, k, and i are defined as above. By relying on these sensitivities and the sales growth rate, we estimate the expected EBITDA for each SME in the case the operations were not affected by any shock as:k belonging to industry i based on the most recent year L, We then estimate the SME specific expected change in sales for the year 2020 without COVID-19 by using the average change in sales for each SME for the 3-year period as follows:For each SME, we can estimate the days of residual life k in industry i due to shock linked to the change of sales i, In order to explore the impact of the current pandemic, we proceed by introducing the industry-specific COVID-19-related shock Also, in this case, we estimate the days of residual life for the ordinary scenario using the below rule:We adjust for the economic shock by keeping into consideration that customers are trying to retain as much cash as possible. Since firms face a stop/reduced activity for around 3/3.5 months (around 30% of the year), we assume that they face a similar lack of cash that implies a similar percentage in terms of debtors’ default. Needless to say, this is an estimate. However, it is also important to point out that any different percentage in terms of payments received/delinquency has a proportional effect on the lack of cash and variation of the residual days.There are two major policies implemented by the UK government to support businesses: CJRS and BBLS. By covering labour costs, the CJRS allows the firm to retain their staff. In addition, the scheme allows the firm to avoid frictional costs linked to making employees redundant (e.g. the notice period and dismissing costs). We estimate the improvement in the EBITDA linked to CJRS to be as follows:We estimate the days of life with CJRS according the rule:As far as the BBLS, the government intervention consists in underwriting bank loans up to 50,000 GBP. The rationale of this intervention is to grant credit access to small firms in a period when banks are not keen to lend because of the deteriorating performance of SMEs and the increased risk of default on loan repayments. BBLS impact is not in terms of cost reduction but in terms of increased cash holdings. To explore BBLS, we adjust the survival days and use to the following rule:so that Our analysis relies on UK data about SMEs with sales and total assets size between 10,000 and 50,000,000 GBP and a number of employees up to 250. Thus, our sample of SMEs is in line with the definition of small and medium enterprise according to the EU standards (European Commission 2003). We use firm-level data obtained from the Fame – Bureau van Dijk – database for the fiscal years 2016–2019. To draw meaningful inferences, we require each SME to have at least 3 years of data. We exclude SMEs classed as public administration, education, health social services (BvD sector), guarantee , and SMEs without employees. Overall, this results in an original sample size of 42,401 firm observations across 28 industries in the UK.Table Table Next, we focus on the two scenarios that include the shock/disruption. First, we estimate SMEs’ EBITDA according to the shock on sales at industry level as generated by COVID-19 (no government mitigation). Second, we estimate the EBITDA by including the two government mitigation policies (CJRS or BBLS). Focusing on the SMEs under COVID-19 scenario (rows 4–6), we find that the average firm in the sample is burning cash  which is reflected via the dramatically lower “survival rate” that drops from 75 to 41%. Besides, the residual life for those SMEs that burn cash is now on average 139 days. When we include the government mitigation policies (rows 7–11), we find that the average EBITDA is still negative . Also, and as a direct result of government intervention, “residual life” for SMEs that burn cash increases to 183 due to CJRS, or  between 189 and 194 (depending on the amount of loan taken). All in all, the government intervention has two positive effects: (1) it reduces the number of SMEs with negative EBITDA by 10% (50.30 vs 41.41%), and (2) it extends the survival days of those SMEs with negative EBITDA (SMEs that are burning cash) by 50 to 60 days. Our results reflect what has been found in Germany  but when the CJRS is taken into consideration so that labour costs are partially covered by the government, the jobs at risk decrease to 20,650 (17% decrease).Further evidence of the effect of COVID-19 and the policies implemented by the UK government emerges from Fig. COVID-19 moves the distribution of the expected EBITDA to the left, increasing dramatically the negative tail of the distribution. The government mitigation policies readjust the distribution moving it to the right. However, EBITDA distribution after the government intervention is more concentrated around the zero than the distribution without COVID-19.Our next step is to explore the effect of COVID-19 on the vulnerable SMEs, that is SMEs with negative EBITDA in the ordinary scenario. The results are reported in Table In fact, these SMEs are expected to burn cash irrespective of COVID-19 and consequently to be at greater risk and have a shorter residual life. The average EBITDA of these firms in the sample is − 2,85 million GBP. Considering the cash holdings these SMEs have, their average expected residual life is 164 days . During COVID-19 scenario (rows 4–6), the EBITDA goes down further , so that the residual life reduces to 119 days (4 months). When we account for the government mitigation policies (rows 7–11), the average EBITDA improves and goes back to levels very close to those of ordinary scenario level . Besides, the survival rate improves to 8.3%. Consequently, the residual life increases to 186 days due to CJRS, or via BBLS between 191 and 194 days, depending on the amount of loan taken. As far as jobs at risks are concerned, there is no difference between ordinary and COVID-19 scenarios (and this is expected as these SMEs have jobs at risk regardless). Thus, the only expected impact would be via CJRS for which the job losses decrease to 9584: by supporting weak SMEs, the governments’ mitigation policy allows SMEs to retain 877 jobs We also estimate the impact on SMEs with a positive EBITDA Table  in orderIn this case, the EBITDA under COVID-19 is marginally negative − 162,000 GBP. A closer look at the distribution of earnings shows that around 53% of the SMEs have negative EBITDA. The expected residual life of strong SMEs is 162 days. The government mitigation policies improve the EBITDA to positive 160,000 GBP, and the number of SMEs with positive EBITDA increases to 65%. In addition, the residual life of the SME with negative EBITDA is between 180 (CJRS only) and 193 days . However, not all the firms that would have been profitable without COVID are profitable under the two governmental schemes since around 35% maintain a negative performance.To further explore the SMEs’ capability to survive the pandemic, we perform two additional checks, focusing on different regions and on different industries , a smaller positive effect of the governmental intervention . However, the differences are not statistically different.All in all, the fact that the results of the robustness test are qualitatively similar to those of the original analysis confirms and reinforces our results in terms of huge negative impact and relatively reduced mitigation impact generated by the government intervention.The various strategies that have been implemented by the governments around the world  in order to deal with containing COVID-19 pandemic are affecting the economy of every country. Despite the intervention governments are implementing, there is a large decline in the economic activity.Governments’ interventions to mitigate this economic shock seems to be mainly focused on allowing SMEs to survive the period of (forced) reduced activity and to retain jobs so that they will be able to jumpstart as soon as the economy reopens. Our evidence for UK SMEs suggests that the CJRS as well as BBLS address the problem but only to a certain extent. In fact, according to our estimate CJRS allows SMEs to cover some costs and protect cash as well as to retain around 17% of jobs that otherwise would have been lost. In addition, the joint effect of CJRS and BBLS allows SMEs with a negative EBITDA to extend their expected residual life by around 2 months (i.e. increase the life under COVID-19 by 35%) so that they can navigate the period of reduced activity and be ready when the economy will restart.The policies implemented in the UK do not discriminate ex ante between strong and weak SMEs. Our comparative results suggest that by helping all the firms without selecting those that merit more support, government is able to protect around 8% of the jobs (that is to reduce job losses that are expected to occur under COVID-19 because its adverse effect on solid SMEs). When we look at the jobs protected in strong SMEs (that is those SMEs that would have been expected to generate positive EBITDA otherwise), the percentage goes up to 23% of the jobs. Besides, the scheme extends the residual life of weak SMEs from 119 to 191/194 days , while in the case of strong SMEs, the scheme extends life from 155 to 188/193 days (that is by 1 month). Nevertheless, the average expected residual life for those SMEs burning cash does not tell the entire story since the distribution is highly skewed. As emerge by looking at Fig. In the ordinary scenario, we estimate that 1498 of the SMEs that are burning cash have only up to 30 days of cash to cover running costs, while additional 541 SMEs have up to 60 days. COVID-19 increases threefold the number of SMEs with less than 30 days of cash (4701) as well as those with up to 60 days . Besides, out of 518 SMEs with between 30 and 60 days of cash under the ordinary scenario, 510 (98%) end up with less than 30 days in the case of COVID-19. This evidence suggests that weak SMEs are hugely adversely affected by both a more negative EBITDA and reduced cash holdings because of an increase in the delinquency levels. All in all, 42% of the SMEs that have less than 30 days of cash under COVID-19 scenario are in fact SMEs that were already very weak .The government intervention mitigates partially the negative impact: SMEs with up to 30 days of cash decrease from 4701 to 2140 by considering CJRS only and to 1550 by considering CJRS and BBLS at 50,000 GBP. Similar reduction is obtained for SMEs with up to 60 days of cash. Thus, mitigation policies can cut up to 60% the number of SMEs that would have been expected to have less than 60 days of cash to cover their negative EBITDA in line with findings in other contexts  the importance to help firms that are facing an unprecedented crisis and (2) the need to identify and use innovative government supporting tools  do not address this aspect since the support provided targets the survival but does not provide the resources to re-start the business . Thus, weak small and medium SMEs can even survive the period with no/or with much reduced sales just to incur the risk to fail resuming their activities because of lack of the extra resources when needed  of the SMEs under three different scenarios: (1) ordinary scenario, expected values based on past performance and not considering any negative effect linked to COVID-19 shock; (2) scenario with the shock on sales at industry level generated by COVID-19; and (3) scenario with the implementation of the UK government policies to support small SMEs .We find that COVID-19 has a huge impact on small and medium firms reducing the percentage of those with positive EBITDA (that we label solid ones) from 75 to 41%. Besides, for those that are defined as weak because they are expected to generate a negative EBITDA, the days of cash available to cover the negative EBITDA goes down from 164 to 139 suggesting that COVID-19 not only increases the number of SMEs in weak position but also intensifies the speed at which cash is burned. At first sight, the government mitigation policies seem to be quite successful in supporting small- and medium-sized firms: on the one hand, the number of SMEs with positive EBITDA increases above 50%; on the other, the residual life for SMEs that burn cash increases to 183 days in the scenario of CJRS, or between 189 and 194 days in the scenario of the joint effect of CJRS and BBLS. All in all, the policies have two main effects: (1) they reduce the number of SMEs with negative EBITDA by 10%, and (2) they extend the life of those SMEs that are burning cash by 50 to 60 days. Moreover, the effect of the government policies on jobs is quite relevant: according to our estimates, the number of jobs at risk, that is jobs in SMEs with negative EBITDA, increases by around 14,000 in our sample. The implementation of CJRS allows some SMEs to turnaround and has a positive EBITDA so that the number of jobs at risk decreases by 17%. However, our analysis on the subsamples of SMEs that generate negative EBITDA irrespective of COVID-19 and those that turn to have a negative EBITDA only because of COVID-19 suggests that the SMEs that benefit the most in terms of extended days of life are those that are weak irrespective of COVID-19. This can have a very relevant negative impact later on, when firms that move from a very weak position may not be able to repay their loans and the government might be asked to step in to cover the losses of default that banks will face , and we rely on estimates in terms of small SMEs’ performance that is based on the 2016–2018 data. Thus, even if we use a relatively larger dataset, we cannot rule out that results can be different if the entire population is used. Besides, even if we perform additional test with more recent data that suggest no qualitatively different results, nevertheless, we cannot rule out that the outcomes can be different when data from the entire population including data for 2019 financial performance is used. Finally, our entire analysis is based on estimation of the current situation faced by SMEs since there are no available data. These weaknesses suggest areas for further research, namely, reproduce the analysis with larger and more updated dataset when they are available. In addition, it can be interesting to cross-check the results we obtained when historical data will be available. Second, our work is limited in terms of area covered: we explore the role of policies in the UK only, but COVID-19 is a world problem. It can be very interesting to explore and compare policies implemented by other countries. For instance, it can be interesting to compare CJRS that has been set up explicitly for the COVID-19 with similar job protection schemes available in Italy or Germany for many years and that have been marginally adjusted to accommodate the dramatic impact of COVID-19 situation. Similarly, it can be interesting to compare the situation for SMEs in the UK that implemented a moderate to rigid lockdown with the one of Italy or Spain that implemented a very strict and rigid lockdown, or with the one of Sweden that decided for a completely different strategy .Notwithstanding the limitation, our work provides a first clear evidence on the impact of the COVID-19 on the UK economy and the effect of the mitigation policies implemented by the UK government.


To assess 2-year endothelial cell loss and graft survival after femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty (FLS-DSEK).n=62, 75.9%) or FLS-DSEK combined with phacoemulsification cataract surgery and intraocular lens implantation  from 2013 through 2016 were included. The graft endothelial cell loss, endothelial graft thickness, visual acuity, and complications after surgery were evaluated.In this prospective and noncomparative study carried out at Eye Hospital of Shandong First Medical University, 85 eyes (84 patients) with endothelial dysfunction receiving FLS-DSEK . Partial graft dislocation was the most common postoperative complication, with an occurrence rate of 14% (n=12), and it was associated with an abnormal iris-lens diaphragm . The other complications included a high intraocular pressure , endothelial graft rejection , and pupillary block . Endothelial graft decompensation occurred in the two eyes, and 98% (n=83) of the grafts survived at 24 months.Thin endothelial grafts were all successfully prepared, with no occurrence of perforation. The rate of endothelial cell loss was 17.4%, 18.8%, 19.9%, and 26.7%, and the central graft thickness was 113±54 μm, 102±40 μm, 101±28 μm, and 96±23 μm at 3, 6, 12, and 24 months, respectively. The median best-corrected visual acuity was 0.4 logMAR  at 24 months, demonstrating a significant difference from that before surgery  (Data of the study suggest that the treatment using FLS-DSEK seems to be promising and might be considered a feasible choice in patients with endothelial dysfunction.1. Date of registration: 2021-02-182. Trial registration number: ChiCTR2100044091https://www.chictr.org.cn/3. Registration site: The online version contains supplementary material available at 10.1007/s00417-021-05383-x. Endothelial keratoplasty has developed rapidly and becomes a major surgical approach to corneal endothelial dysfunction –3 since Eighty-four consecutive adult patients (85 eyes) with endothelial dysfunction receiving FLS-DSEK (62 eyes) or FLS-DSEK combined with phacoemulsification cataract surgery and intraocular lens (IOL) implantation (23 eyes) by the same surgeon (W.S.) at Eye Hospital of Shandong First Medical University from May 2013 through April 2016 were included in the analysis. In addition to endothelial dysfunction, the patients also suffered from other eye diseases. This prospective study was approved by the Institutional Review Board of Eye Hospital of Shandong First Medical University (No. 201302) and adhered to the tenets of the Helsinki Declaration. Written informed consent was obtained from each patient.In patients requiring combined surgery, phacoemulsification and IOL implantation were performed before FLS-DSEK.The FS200 femtosecond laser  was used for side cutting at 90° with settings of a frequency of 200 kHz and energy of 1.4μJ Fig. , 1b. TheThe artificial anterior chamber was filled with Optisol corneal storage medium  using a syringe to maintain the chamber pressure within a range from 40 to 50 mmHg for protection of the donor corneal endothelium. After adjustment of the applanation cone and the side cutting area, a corneal incision was created at the corresponding depth using the femtosecond laser. A manual lamellar cutting of 2 mm of the corneal periphery Fig.  was follA 7.75- to 8.25mm-diameter epithelial mark, which was determined according to the size of the recipient’s cornea, was created using a trephine Fig.  to outliThe prepared endothelial graft was placed with the endothelial side up on the carrier at the front of the EndoSerter  and instilled with a small amount of viscoelastics Fig. . After pPostoperatively, endothelial cell loss, central endothelial graft thickness, total central corneal thickness, visual acuity, graft survival status, and complications including graft dislocation, high intraocular pressure, and graft rejection were evaluated.Specular microscopy  was performed to measure the endothelial cell counts. The rate of postoperative endothelial cell loss, which is expressed as a percentage, was calculated as the preoperative donor endothelial cell density (ECD) minus ECD at 3, 6, 12, and 24 months and then divided by the preoperative ECD. The loss rate was also compared with the results of other related studies , 16.t test was used to compare the total central corneal thickness before surgery and at 24 months after surgery. The decimal vision was transformed into LogMAR for analysis with the nonparametric test to evaluate differences between the visual acuity before and at 24 months after surgery. The Spearman test was used to analyze the correlation between iris-lens diaphragm abnormalities and graft dislocation.The endothelial graft thickness and the total central corneal thickness were measured by optical coherence tomography . The Corneal endothelial graft failure was defined as failed restoration of the corneal transparency or secondary corneal edema, subepithelial blisters, and endothelial decompensation requiring repeated surgery after the restoration of clarity. The survival rate of the corneal endothelial grafts at 24 months after surgery was calculated according to Kaplan-Meier analysis.P<.001 was considered statistically significant.SPSS19.0  was used for statistical analyses. Basic descriptive statistics were calculated and reported as the percent for categorical data, as the mean ± standard deviation for normally distributed data, or as the median and range for nonnormally distributed data. A total of 84 patients  aged 58±15 years  were included in this study. The surgical indications and specific procedures performed are presented in Table 2 before surgery, and 1990±422 cells/mm2, 1958±489 cells/mm2, 1932±445 cells/mm2, and 1765±387 cells/mm2 at 3, 6, 12, and 24 months, with a cell loss rate of 17.4%, 18.8%, 19.9%, and 26.7%, respectively. The endothelial cell loss was most obvious at 3 months after surgery. Due to the role of endothelial cells, corneal edema was gradually alleviated. The total central corneal thickness was 572±91 μm at 24 months, which was significantly thinner than before surgery (802±164 μm) . Moreover, the endothelial graft thickness decreased with time .All eyes had corneal edema and subepithelial blisters before surgery Fig. ; the corr=0.35, P<0.001).None of the 85 eyes suffered intraoperative complications. No perforation occurred during graft preparation, and endothelial grafts were successfully obtained from all 85 donor corneas. Postoperatively, partial graft dislocation was observed in 12 eyes (14%), 10 of which were treated with sterile air injection under topical anesthesia and two with repeated injection, after which the grafts were observed to be well attached to the beds. The rate of partial graft dislocation was 31% (9 in 29 eyes) in the eyes with an abnormal iris-lens diaphragm and 5.4% (3 in 56 eyes) in eyes with a normal iris-lens diaphragm. The partial graft dislocation was closely related to iris-lens diaphragm abnormalities, including aphakia, iris atrophy, and pupillary iris defects ((Online resource 1b). The endothelial cell damage caused by graft immune rejection was irreversible. In these four eyes, the rate of the mean endothelial cell loss after the occurrence of rejection was 20.6% compared with the cell counts at the final follow-up before rejection. One eye suffered a pupillary block on the first day after surgery, and it was improved following a surgical intervention of anterior chamber reconstruction combined with peripheral iridectomy.Five eyes developed high intraocular pressure, which was controlled with local medical therapy in four eyes and trabeculectomy at 4 months after surgery in one eye whose response to medication was not well. Four eyes showed endothelial graft rejection  with keratic precipitates observed on slit lamp microscopy (Online resource 1a). After local and systemic anti-rejection treatment, the keratic precipitates disappeared n= 83) at 24 months  using a microkeratome , it is bAlthough DMEK can obtain the thinnest corneal grafts, the preparation procedure is not easy, with a failure rate of 8% , 23. UsiP<.001). Compared with the results in previous reports [Our FLS-DSEK effectively reduced the damage to corneal endothelial cells, and the loss rate was only 17.4%, 18.8%, 19.9%, and 26.7%, respectively at 3, 6, 12, and 24 months. In a multicenter study about the femtosecond laser-assisted endothelial keratoplasty in the Netherlands , the end reports , 25, 31,In the current study, a femtosecond laser was only used for side cutting to minimize the injury to endothelial cells induced by the laser. With femtosecond laser, individualized graft diameter (ranging from 8.0 to 8.5mm) can be accurately determined according to the diameter of the patient’s cornea.r=0.35, P<.001). The rate of graft dislocation was as high as 50% in the earliest ten cases of DSEK [P<.001).Corneal endothelial graft dislocation is the most common postoperative complication after corneal endothelial transplantation , 33. We  of DSEK , 25% aft of DSEK , and eve of DSEK . In our From this observational study, we noticed that FLS-DSEK can achieve favorable therapeutic results, but the femtosecond laser parameter settings and operation of upper corneal tissue cutting combined with blunt dissection, thus creating a smooth anterior graft surface, is much more technically challenging than using a microkeratome and may affect the visual acuity, which present high requirements for surgeons. In addition, the procedure is much more costly compared to the methods using a keratome, or DMEK. What is more, in this preliminary study observing this new modified technique itself, the outcomes are satisfying, but a longer follow-up, a large sample analysis, and comparative studies with other surgical methods are needed for a comprehensive evaluation.Online resource 1a Slit lamp microscopy observes endothelial graft rejection with keratic precipitates. b After local and systemic anti-rejection treatment, the keratic precipitates disappears and the cornea restores transparency (PNG 3294 kb)Comparison before and after anti-rejection treatment. High resolution image (TIF 12178 kb)Online resource 2Functions image of endothelial graft survival at 24 months after femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty (FLS-DSEK) treatment for corneal endothelial dysfunction (PNG 5630 kb)High resolution image (TIF 2724 kb)Online resource 3Comparison of endothelial cell survival rate after femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty (FLS-DSEK) with that after conventional Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK) (PNG 5635 kb)High resolution image (TIF 3392 kb)Online Resource 4Surgery video of femtosecond laser semi-assisted Descemet stripping endothelial keratoplasty: endothelial graft preparation and donor insertion (MOV 15952 kb)