HORVU6Hr1G087920, HORVU5Hr1G011230, HORVU5Hr1G011270 and HORVU5Hr1G011280, showed the high expression in the developing barley grains when starch accumulates rapidly. The examined 100 barley accessions could be divided into two groups based on the polymorphism of the marker S5H_29297679, with 93 accessions having allele GG and seven accessions having AA. Moreover, significantly positive correlation was found between the number of favorable alleles of the identified QTLs and TS, AC, AP content. In conclusion, the identified loci or genes in this study could be useful for genetic improvement of grains starch in barley.The content and composition of starch in cereal grains are closely related to yield. Few studies have been done on the identification of the genes or loci associated with these traits in barley. This study was conducted to identify the genes or loci controlling starch traits in barley grains, including total starch (TS), amylose (AC) and amylopectin (AP) contents. A large genotypic variation was found in all examined starch traits. GWAS analysis detected 13, 2, 10 QTLs for TS, AC and AP, respectively, and 5 of them were commonly shared by AP and TS content. qTS-3.1, qAC-6.2 and qAP-5.1 may explain the largest variation of TS, AC and AP, respectively. Four putative candidate genes, i.e.,  Hordeum vulgare L.) ranks the fourth largest cereal crop in term of planting area worldwide, only after maize, rice and wheat (FAOSTAT 2018). Like other cereals, the main composition in grains of barley is carbohydrate, mainly starch, which occupies approximately 62–77% of total dry weight , pr, prp-val10RPKM) of candidate genes. The genetic map was operated by using MapChart 2.2.0.0. .The distribution frequency, correlation and haplotype analysis, and variance analysis were conducted using IBM SPSS Statistics 25 software . The expression data were obtained from the BARLEX publicly available database and heatmap of candidate genes was drawn by TBtools  with the


We examine the role of gender dimensions of intrahousehold bargaining power and decision making in the adoption and diffusion of orange sweet potato (OSP), a biofortified crop being promoted to increase dietary intakes of vitamin A in Uganda. We use patterns of ownership and control of land and other assets by married men and women to create gender-disaggregated indicators of bargaining power, allowing for joint and sole ownership and control of land and assets. Using data from an experimental evaluation of a project promoting OSP adoption, we find that the probability of adopting OSP is not affected by the exclusive or joint control of assets by women at the household level. However, within households, parcels of land under joint control, in which the woman has primary control over decision making, are significantly more likely to contain OSP. Women who control a higher share of household nonland resources are more likely to share OPS vines, showing that women use greater bargaining power to facilitate diffusion of this health-promoting technology. We do not find any impact of women’s bargaining power on children’s dietary intakes of Vitamin A, possibly because husbands and wives have the same preferences regarding their children’s nutritional status. These results contribute to reshaping our understanding of household decision making to inform the design and implementation of agriculture-nutrition interventions. It involves breeding staple food crops to be a rich source of one or more key micronutrients, such as iron, zinc, and vitamin A, and disseminating these crops in areas where micronutrient deficiency is high and where poor households consume a large share of calories from staple foods . The sucUntil fairly recently, agricultural extension efforts assumed that households acted “as one,” consistent with a unitary model of the household in which individuals pooled resources and shared the same preferences . With emWe study the role of gender and bargaining power in the adoption and diffusion of biofortified orange sweet potato (OSP), in a project that disseminated OSP to 10,000 households in Uganda from 2007 to 2009. In 2007, the HarvestPlus “Reaching End Users” (REU) project introduced OSP with the goal of increasing dietary intakes of vitamin A and reducing the prevalence of vitamin A deficiency. OSP is a dense source of vitamin A. It is moderately higher yielding than conventional white or yellow sweet potato varieties but is more vulnerable to rot during dry periods. The REU project provided a free one-time distribution of 20 kg of OSP vines to members of selected farmer groups; trainings on OSP cultivation and marketing; limited support on marketing of OSP roots; and trainings for women on the nutritional benefits of consuming OSP and other vitamin A sources.This paper has three objectives. The principal objective is to analyze how household heads’ and spouses’ bargaining power and decision making may have influenced OSP adoption. A secondary objective is to examine whether women and men in spousal pairs differentially contributed to OSP diffusion, through farmer-to-farmer exchange of planting material. Finally, we examine whether bargaining power mediates the impact of the REU intervention on dietary intakes of Vitamin A among beneficiaries.We use a broad definition of bargaining power that encompasses the stock of human, natural, and physical assets that men and women control . Some ofThis paper expands the analysis of an experimental impact evaluation of the REU project to focus more closely on how gender roles and intrahousehold bargaining may mediate the outcomes of the intervention. The evaluation showed that the REU project led to adoption of OSP by 65% of project households, compared to just five percent in the control group . The proIn order to better understand the success of this initial introduction of OSP, it is necessary to examine the gender dynamics of intrahousehold decision making in order to find the most cost-effective strategies to promote OSP, so that households will continue to grow it and feed it to their children. The gender dynamics that matter most in these households are those involving spousal pairs—between the wife of the male head of household and her husband, and between the husband of the female head of household and the female head—even if other women and men within these households may also have decision-making influence. Because we have data on bargaining variables only for the wife/female head and the husband/male head, we use these as measures of bargaining power of women and men, restricting the sample appropriately in our analysis.In Uganda, our survey data document that women play an active role in crop selection (particularly for food crops) and commonly supply labor on household farms. Complementary qualitative research  confirmsThe speed of diffusion is central to the success of any agricultural intervention where OSP vines are distributed. For many seed crops, adoption can be encouraged through marketing campaigns, but for vegetatively-propagated crops such as sweet potato, planting material such as vine cuttings cannot be stored, making marketing ineffective as a primary dissemination strategy. Instead, most households obtain planting material for these crops through interaction with other households. Indeed, the market for OSP vines was limited at the start of the project. The project offered limited trainings on marketing to encourage households to sell their OSP vines commercially, but markets for OSP only began to develop in one of the three project districts. In contrast, we document that sharing of planting material was common – on average each beneficiary household gave OSP vines to at least one other household. Understanding what factors, including bargaining power, were conducive to such diffusion has implications for the design of cost-effective adoption strategies.As noted earlier, the REU resulted in improving dietary intakes of Vitamin A among young children. We want to analyze further whether bargaining power mediates not just adoption and diffusion, but also improved nutrition. Vitamin A deficiency causes night blindness and contributes to child morbidity and mortality. Globally, vitamin A deficiency afflicts 127 million young children  and is rThis paper is organized as follows. 2This conceptual framework  does notWe expand this conceptual framework to focus on the possible influence of gender roles and bargaining power at different points along the impact pathways  is characterized by heavier rains than the second season (August-December). Through pre-intervention (baseline) and post-intervention (endline) surveys, the project assessed OSP adoption rates and whether adoption resulted in improved vitamin A intakes among young children and their mothers.(i)a one-time free OSP vine distribution to project households in August 2007,(ii)agricultural extension services related to OSP production practices and marketing opportunities given to men and women who were members of project farmer groups,(iii)nutrition training, particularly about vitamin A, given to women in these same households, and(iv)modest marketing activities for OSP roots and processed products.The OSP intervention included four components:3Several other aspects of the project and the sample could shape the gender dimensions of OSP adoption. For example, at baseline, nearly sixty percent of farmer group members in the project were women . Also, a3.2The impact evaluation sample includes 84 farmer groups from three districts: Kamuli, Bukedea, and Mukono where white and yellow sweet potato is commonly grown and consumed. Farmer groups were sampled from a list of active farmer groups stratified by district. These farmer groups and households in the village that is home to the largest number of its members represent the sample clusters in the data. Forty-eight of these farmer groups were randomly assigned to the treatment group, and 36 to the control group.Households with children 3–5 years of age (36–71 months) were sampled, with 14 households per cluster based on power calculations.6Data collection took place in two survey rounds, a baseline survey in 2007 and an endline survey in 2009. Both rounds included a detailed socioeconomic survey and a nutrition survey, including a detailed 24-hour dietary recall module. The attrition rate was 7.6% over the two-year period, which is reasonably low relative to other panel surveys .The profile of OSP adoption over the four seasons of the project among participant households is shown in 3.3We use two main measures of bargaining power to examine how intrahousehold gender relations affect OSP adoption decisions. Although We also examine the role of gender in parcel-level models of adoption, based on information on the sex of the decision-maker over each parcel of land. In particular, we differentiate the effects of gender on crop choice by whether crop decisions on a parcel are under the sole control of a man, whether they are solely controlled by a woman, or whether the parcel is under joint control, with either the man or the woman taking the lead in making decisions regarding that parcel. In addition, we also consider the role of human capital, embodied in nutrition knowledge, and social capital, proxied by leadership of a farmer group and the number of years that the household belonged to a farmer group.3.4To test the hypothesis that OSP adoption is affected by spouses’ bargaining power, we estimate an adoption equation using a logit specification:i)P, total land area, whether the household had access to a lowland parcel, the share of “good” or fertile soils. We also include indicators that may indicate a potentially higher probability of adopting OSP, as of 2007, including previous experience in growing OSP, whether the respondent ever changed farming practices as a result of advice received, whether the mother knew what vitamin A was at baseline, whether the mother has access to any radio, whether the respondent is a farmer group leader, the number of years as a farmer group member, the share of sweet potato in planted area, and whether the respondent ever gave farming advice. These values are all evaluated at baseline so that they would be exogenous to extension messages given during the project. Note that because nutrition training was only provided to women, coefficients on nutrition knowledge reflect both the effect of the increased nutrition knowledge as well as differences in preferences. District dummy variables are included, with Kamuli as the excluded category. 44.1To provide an overview of the factors affecting the determinants of OSP adoption, we take advantage of the experimental design by first estimating the household-level probability of adopting OSP over our estimation sample of treatment and control households, estimated both for all four seasons of the project (from second season 2007 to first season 2009) and for the fourth season only . The logit models, shown in In all specifications, the coefficient on the treatment dummy is significant and positive, a reflection of the successful dissemination effort of the REU project. However, none of the bargaining power variables—the fraction of land and nonland assets exclusively or jointly owned—are significant.12However, analysis at this level of aggregation may mask a more complex decision-making process occurring within households. Most households have access to at least two parcels of land for farming and may have worked out an implicit agreement over which household members control crop choice and farming decisions on each parcel. For a particular parcel, the crop choice decision may be a joint decision by the household head and spouse, or a particular household member may maintain sole control over the parcel. However, a household member with sole control over a parcel may still consider the crops being grown on other parcels when making crop choice decisions for that parcel. Although several recent papers have highlighted the importance of intra-household analysis of agricultural productivity, the evidence on whether there are gender differentials in crop productivity, and the sources of these differentials is mixed and context specific. Variables such as input use intensity, security of land tenure, and access to resources are all important determinants of such differentials; recent estimates suggest that yield differences between male- and female-managed plots not only come from differences in control of resources, but also from differences in returns to a given bundle of resources  of the female headed households in this sample (which are primarily single-headed households headed by women), solely women-managed plots are also found in about 19% of the male headed households. This may partly be due to women having sole control of plots that are of lower quality or with smaller areas. Only 4.5% of parcels are reported to be controlled exclusively by a man, while the remaining 16.5% of parcels are under joint control with a woman taking the lead in the decision making.At the parcel level, the probability of adoption of OSP in 2009 is higher for parcels controlled exclusively by a woman than for parcels exclusively controlled by a man or under joint control but with a man taking the lead, as shown in We account for these in 13It is important to keep in mind that these effects of bargaining power on parcel-level decisions to grow OSP do not capture the effect of bargaining power on prior negotiated assignment of decision makers to parcels. Rather, these estimates show that, conditional on those assignments, OSP is more likely to be grown on jointly managed parcels where women exert greater control. This provides evidence that, within households, either women are more likely to choose to grow OSP when they have the opportunity to do so (on plots they control) or that men and women agree to grow OSP and the crop ends up on women-controlled plots as a result of intrahousehold specialization of tasks. Either interpretation documents substantial cooperation between spouses as well as the importance of women’s (shared) control over farming decisions.mailo arrangements. Mailo is a form of land tenure that provides rights to occupants of land owned by someone else; it is common in the Buganda region of Uganda (Mukono district). Consistent with other evidence from Uganda that more secure tenure creates incentives to plant permanent crops  on all of its parcels at baseline. This suggests that households are substituting area under production with white or yellow sweet potato with OSP, as anticipated by the biofortification program. OSP adoption is less likely on farms with larger land holdings, but conditional on total landholdings, OSP is more likely to be grown on parcels with more land area. Land tenure also affects crop choice decisions: parcels under the free hold land tenure status are less likely to be selected for adopting OSP, although this relationship is only weakly significant in column 2. Free hold tenure arrangements provide greater security of land tenure than the more common customary or nt crops , farmersNone of the models presented so far account for potential correlations of decisions of what to grow across parcels within the household. When we account for this in estimation (column 3) using a conditional logit model, the pattern of effects remains similar. Results in column 3 present the odds ratio of the probability of adopting OSP compared to parcels under joint control with a man leading decision making. The point estimates suggest that the probability of adopting OSP is highest on parcels with joint control and a woman leading decision making and lower on parcels under control of a single gender, but these estimates are not significant. One reason for the insignificance may be the smaller sample in column 3  than in column1. As mentioned earlier, the estimation sample was harmonized to eliminate item nonresponse across all tables. Results from estimating the specifications in 4.2The cost-effectiveness of the REU project as a biofortification strategy to improve dietary intakes of vitamin A would be greatly improved if households in the project shared OSP planting material with other households. Only a small amount of OSP planting material is needed to start a small plot, so project households could share planting material with others without significantly affecting their productivity. However, the vine cuttings must be transplanted within a day or so, else they wither and die. This feature discourages large commercial operations selling OSP planting material. In our survey, most households at baseline reported receiving their traditional sweet potato vines from neighbors and friends. The potential for this exchange is shaped by the patterns of interactions between households in a community. Women and men have overlapping but often different social or information spheres. An important question is how these gender-differentiated spheres of interaction play a role in OSP diffusion. In related work, On average, each household in the project gave OSP planting material to 1.2 other households during the two years of the project. We examine the role of women and men farmer group members as well as the role of women’s bargaining power in the household’s decision to participate in OSP diffusion. Results, based on the 415 treated households, are presented in Interestingly, the share of land area controlled by women in the household does not have a significant effect on the probability of conducting diffusion in the full sample. Instead, the share of nonland asset value either exclusively or jointly under the control of women is positively associated with the probability of diffusion. Women who control a higher share of household nonland resources are more likely to share this nutrition-promoting agricultural technology, which is likely to help the women build social capital within their communities. The result that bargaining power based on nonland assets plays a bigger role in prompting women to share OSP vines than the share of land women control may indicate that bargaining power based on land is more restricted by longstanding norms on land rights obtained through marriage, which would have been determined at the time of household formation.Among households participating in project farmer groups, whether a household has at least one woman farmer group member does not affect the probability of the household undertaking any diffusion during the project. However, households in which the woman was a farmer group leader, or otherwise gave advice on farming in the baseline, were far more likely to share vines with others. Also, irrespective of the specification of women’s bargaining power, the probability of sharing the OSP crop increases significantly if the mother has some knowledge about vitamin A at baseline. These appear to be important channels to promote farmer-to-farmer diffusion and also reflect the woman’s stock of knowledge  and social capital (due to her leadership in the farmer group).4.3Finally, we examine the effect of women’s bargaining power on dietary intake of vitamin A by children in the reference group of 3–5 year olds. Improving dietary intakes of vitamin A for this group of reference children was a major objective of the project. The impacts of the project on dietary intake of vitamin A are reported in ,The results show a weakly statistically significant effect of the REU intervention on dietary intake of vitamin A  and farmer group participation in the diffusion of the OSP crop technology, but not on Vitamin A intakes. The insignificant impact of bargaining power variables on children’s vitamin A intakes may reflect very similar preferences between spouses for child nutrition, so the treatment effect rather than the bargaining variables dominates. It is also possible that the effects of bargaining power are domain specific.These results contribute to reshaping our understanding of household decision making, and in turn, the design of agriculture-nutrition interventions. Even if decisions to grow OSP involve only a small portion of the household’s land, these decisions are both economically and nutritionally important. The economic importance of OSP adoption arises from its being a dense source of vitamin A. Low dietary intake of vitamin A is associated with higher child morbidity and vitamin A deficiency is a major contributor to child mortality globally. Efficacy trials have shown that consuming just 125 g of orange sweet potato improved vitamin A status (vitamin A liver stores) in children age 5–10 years in South Africa . Thus, eWhile substantial evidence supports a non-unitary model of the household, bargaining models have focused on individually consumed goods (or leisure) rather than joint production or consumption of the public good . NeglectFraming nutrition-sensitive agricultural interventions in the context of cooperation and joint interests, rather than as a zero-sum game, may increase support for such programs, and may eventually lead to the adoption of technologies and behaviors that promote desired nutritional goals and other development objectives. Indeed, recognizing the different preferences of household members and strengthening cooperation within the household is the core of the International Fund for Agricultural Development’s household methodologies approach . More reDaniel O. Gilligan: Conceptualization, Formal analysis, Investigation, Writing - original draft. Neha Kumar: Conceptualization, Formal analysis, Investigation, Writing - original draft. Scott McNiven: Investigation, Conceptualization . J.V. Meenakshi: Conceptualization, Writing - review & editing. Agnes Quisumbing: Conceptualization, Investigation, Writing - original draft.


PurposeTo evaluate small-size hamstring (HS) autografts for biomechanical properties and determine a threshold diameter necessary for appropriate reconstruction.MethodsIn a controlled laboratory setting, biomechanical testing was performed upon 15 hamstring autografts. The grafts were divided into three groups by diameter, with five grafts each at diameter sizes of 6, 7, and 8 mm. Testing of the specimens was performed using an MTS 858 . We determined load to failure by looking at the maximum load as well as the stiffness of the graft. Statistical analysis was performed via analysis of variance (ANOVA) testing with Tukey's post-hoc test and P-values set at 0.05.ResultsThere was a significant difference in ultimate tensile strength for the different size grafts: 1990 +/- 302.42 N for 6 mm grafts (n=5), 2179 +/- 685.36 N for the 7 mm grafts (n=5), and 3074 +/- 781 N for 8 mm grafts (n=5). This was statistically significant for the group overall (p=0.039), as well as between the 6 mm and 8 mm grafts (p=0.044). Graft stiffness for the 6 mm grafts was 317 +/- 85 N (n=5), 288.6 +/- 66 for 7 mm grafts (n=5), and 428.053 +/- 83 for 8 mm grafts (n=5). This achieved statistical significance for the group overall (p =0.037) as well as between the 8 mm and 7 mm grafts.ConclusionsThe biomechanical data presented here demonstrate that graft diameter is highly correlated with ultimate tensile strength and stiffness.Clinical relevanceWhen viewing this biomechanical data in conjunction with prior clinical data, consideration should be given for the supplementation of an HS autograft as the size decreases below 8 mm. Anterior cruciate ligament (ACL) injuries are common, and surgical reconstruction of anterior cruciate ligament tears is the most frequent knee ligament reconstruction procedure performed in the United States . Modern A common reconstruction technique uses a hamstring tendon (HT) autograft for ACL graft reconstruction -14. HistBiomechanical cadaver studies have demonstrated that the mean biomechanical strength to resist the maximum tensile load of the native ACL is approximately 2160 N in young adults (age 22-35). As adults age, this maximum tensile strength has been shown to decrease. Stiffness of the native ACL, defined as the ultimate load at failure compared to the cross-sectional area of the ACL, also decreases with age -20.Studies of HT autografts show the doubling of the gracilis or semitendinosus approach, with a tensile strength of 1550 and 2630 N, respectively, of the native ACL . The quaAlthough these prior studies demonstrate increasing biomechanical strength with increasing graft diameter, previous studies do not provide biomechanical evidence to support a specific ACL graft diameter for reconstruction. Thus, the purpose of this study is threefold: 1) to evaluate small size hamstring graft  for biomechanical qualities , 2) to determine a threshold diameter of a looped graft necessary for appropriate reconstruction, and, thus, 3) to determine at what diameter should consideration be given to supplement an HS autograft.There are no conflicts of interest to disclose from the corresponding authors of this manuscript. This project was funded internally by the University of Florida. This research involves cadaveric specimen testing utilizing tabletop biomechanical devices, and thus is exempt from Institutional Review Board approval.In a controlled laboratory setting, biomechanical testing was performed upon 15 hamstring grafts. The hamstring grafts were harvested from cadaveric specimens of ages 50-70. Harvesting of the semitendinosus and gracilis tendons was performed using standard autograft techniques. A 3-cm longitudinal incision centered between the tibial tubercle and the posteromedial border of the tibia was utilized. The sartorius fascia was divided parallel to the superior border of the semitendinosus tendon and reflected inferomedially. The semitendinosus and gracilis tendons were identified on the deep surface and harvested with a tendon stripper. All grafts were stripped of muscle and were then pre-soaked in normal saline for 20 minutes. After preparation, the diameter of the graft was identified using standard sizing tubes in an ACL combo set. The grafts were pulled through the smallest-possible diameter tube without damage to the graft. The sizing procedure was confirmed and repeated three separate times.The 15 hamstrings grafts were divided into three groups by diameter, with five grafts each at diameter sizes of 6, 7, and 8 mm. There were five quadruple strand grafts  and 10 double-strand grafts . Grafts were prepared to approximate similar tension across all strands.Testing of the specimens was performed using a validated, commercially available materials testing device . The hamstring graft specimens were secured by the free end with clamps. They were then frozen into the clamps with dry ice before final tightening Figure . The looIn order to determine creep, we pre-tensioned the graft. We performed cyclic loading of 50-250 N @ 1 Hz for 1000 cycles. We determined load to failure by recording the peak load prior to graft rupture or subsequent load decrease, and stiffness of the graft was calculated by comparing the maximum load at failure to the cross-sectional area of the graft. All failures were mid substance. Statistical analysis was performed via analysis of variance (ANOVA) testing with Tukey’s post-hoc test and P-value set at 0.05.There was a significant difference in ultimate tensile strength (UTS) for the different size grafts: 1990+/-302.42N for 6 mm grafts (n=5), 2179 +/- 685.36N for 7 mm grafts (n=5), and 3074+/-781N for 8 mm grafts (n=5) , 288.6+/-66 for 7 mm grafts (n=5), and 428.053+/-83 for 8 mm grafts (n=5)  between cycle 10 and cycle 1000. This did not reach statistical significance as a group or when comparing the 6, 7, and 8 mm grafts (Tables 0 N betwePrevious data demonstrated that quadruple-strand grafts have superior strength versus maximum loads when compared to double or single strand grafts, and graft cross-sectional area has been strongly correlated with graft strength . StudiesOur study demonstrated that the UTS of HT grafts of diameter 8 mm was greater than or equal to that of the native ACL. In addition, the difference in UTS between 6 and 8 mm grafts was statistically significant. The difference in 6 and 7 mm grafts did not reach statistical significance although there was a trend toward suboptimal strength (Table The biomechanical data of our study would support the clinical data published by Magnusson et al., which demonstrated that smaller diameter HT grafts had increased rates of revision . Grafts Some prior studies have also attributed gender as an independent risk factor for revision when undergoing HT autografts -25. Ma eThe limitations of our study include our sample size of harvested tendon-grafts, the cadaver age for harvested tendons and resulting tendon variability, and the method of testing tensile strength. Additionally, prior studies demonstrate that the weakest part of a reconstruction construct are the bony fixation points -28. Our ACL reconstruction surgery is one of the most common ligamentous reconstruction procedures. Autologous hamstring grafting is an attractive choice for reconstruction. Previous clinical data has shown smaller grafts have an increased rate of revision surgery. The biomechanical data presented here demonstrate that graft diameter is highly correlated with ultimate tensile strength and stiffness. When viewing this biomechanical data in conjunction with prior clinical data, consideration should be given for the supplementation of HS autografts that fall below 8 mm.


Governments are increasingly focusing their efforts on stimulating innovation within small and medium-sized enterprises (SMEs). As a result, university-industry-government collaboration is gaining importance among the agenda of policymakers to enable open innovation in SMEs. However, these inter-organisational relationships often fail to meet expectations, especially when projects are oriented to pre-competitive R&D. Nevertheless, the literature has not yet provided sufficient evidence of the challenges related to the participation of traditional SMEs  in this specific type of collaboration. We collected qualitative data to analyse longitudinally three pre-competitive projects, exploring the main challenges faced by traditional SMEs. We have bracketed the projects in four phases: initiation and planning phase, execution phase, closing phase, and monitoring and control phase. For each of these phases we have individuated firm- and project-level challenges, providing practical and theoretical insights for open innovation scholars. Our society is increasingly facing rapid and sudden changes caused by macro phenomena over which there is little control. The crisis triggered by the COVID-19 pandemic represents the latest emblematic example of how uncertain the economic scenario is and how companies must be able to develop increasingly immediate and disruptive responses to ensure competitiveness and sustainability. This is also affecting more traditional sectors and companies. In particular, many small- and medium-size enterprises (SMEs), which represent the core engine of the economy of many countries, seem to no longer have a secure future unless they constantly innovate their products, processes, and business models.Recent literature on innovation and entrepreneurship has highlighted how the complexity of today’s business environment requires collaborative efforts by multiple actors  the main challenges in the initiation and planning phase are lack of innovation strategy and a lack of partner mapping at the firm-level and goal incongruence and the presence of unknown partners at the project-level; (2) the major barriers in the execution phase of the project are inadequate information systems, time pressure, and lack of resources at the firm-level and goal redefinition, underestimation of partners’ efforts, and numerosity and heterogeneity at the project-level; (3) relevant challenges in the closing phase are lack of commitment post-project at the firm-level and delays in goal achievement and ineffective policies at the project-level; (4) finally, the most recurring barriers in the transversal phase of monitoring and control are inadequate management control systems at the firm-level and bureaucratisation at the project-level.This study extends the literature on open innovation. In its early stages, research on open innovation has predominantly focused on the analysis of high-tech start-ups and incumbents while traditional SMEs, despite the importance occupied within national and regional economies, started attracting the attention only recently  the network was composed of at least one large company, one SME, and one research organisation or university; (2) at least 30% of the total eligible costs for the realisation of the project was allocated to SMEs; (3) taken together, these three cases covered a wide range of industries . For the purpose of the study, we focused our analysis on traditional SMEs , which represent 55% of the SMEs involved in the three projects.To deepen our understanding of the challenges that traditional SMEs face in pre-competitive university-industry-government collaboration, we developed a qualitative methodology able to produce in-depth and illustrative information on the various dimensions of the phenomenon under analysis, representing the views and perspectives of multiple actors . Since inter-organisational projects are based on temporary collaborations, there is the concrete risk that at the end of the project all the partners return to their daily needs and activities, leaving the perspective of collaborating with each other. This is particularly frequent in SMEs, which have to deal with their day to day operativity. This practical conclusion is rather common, and it is precisely for this reason that policymakers, in this case regional governments, should look at it more carefully. According to the opinion of a project leader, “the main risk that usually characterises 90% of these types of initiatives, is that everyone goes their own way once the project is closed. Except for a few virtuous relationships, which are established and develop mainly at the dyadic level, the network that has been created and that has given value to this project dissolves after the closure. This is quite natural because the network is composed by such different entities with different objectives, and when there is no longer a common goal the synergies that had been created get lost. [...] Policymakers should pay more attention to this element by promoting and financing the most promising consortia again, since they will presumably also create value in the subsequent projects”.Two out of the three projects were postponed for six months due to the delay in reaching the objectives in some work packages. There were multiple causes and they depend on the critical issues analysed previously. The extension of the projects and the delays in reaching the objectives represented a deterrent to the desire of taking part in similar projects again. Many SMEs have in fact complained about the excessive slowness of the project activities (S12: The main contributions of this study are specific to open innovation (and its subsets of university-industry-government relationships and publicly funded pre-competitive collaboration). Research on open innovation has traditionally focused on the analysis of large companies and high-tech start-ups (Brunswicker and Vanhaverbeke In order to provide a strong theoretical contribution to these research domains we analysed the challenges that can hamper effective collaborative innovation in SMEs as well as their effective involvement in regional entrepreneurial ecosystems (Brunswicker and Chesbrough Public incentives for R&D are as diffused as they are questioned, since there is often contrasting evidence of their effectiveness. Indeed, publicly funded projects can be a powerful tool for enhancing collaborative innovation in less experienced SMEs, but, at the same time, SMEs can use public money for ordinary activities, minimising costs instead of effectively innovating (Wang et al. To reduce the effort of SMEs, projects should activate mechanisms, such as internships, to provide SMEs with human resources to dedicate to the project. Eventually, incentives could be allocated to also encourage the hiring of these resources within companies and ensure greater continuity. In this regard, it would also be interesting if the funding body of the initiative can in some way guarantee an engagement in a subsequent project oriented towards the R&D commercialisation phase for those consortia that have proven to be productive and successful.Regarding the accounting aspect of the projects, considering that SMEs often have basic accounting systems and that relying on external consultants could represent an excessively expensive and detrimental cost for SMEs, the projects should consider creating a special body that can support SMEs with coaching activities for project reporting.Then, since collaboration among different stakeholders often leads to frictions and misunderstandings, it is important to pay particular attention to the selection phase of the project, which has not yet been deeply investigated by the literature. To reduce opportunistic behaviour, the lack of clear ideas already mentioned and the lack of prior mutual knowledge, the projects should first consider reducing the numerosity and the heterogeneity of the consortia, and, second, they should establish clear and rigorous criteria for the process of consortium creation. This means that the project leader should directly and personally select the SMEs whose goals are supposed to be aligned with the scope of the project. The underestimation of partners’ efforts should be reduced by incentivising mutual understanding. In this regard, it is important that projects leverage mechanisms that increase trust between partners. When there are differences in terms of language, culture and organisational structure, it is important to stimulate informal knowledge exchange to encourage interactions that are not limited to the official steering committee or to the formal deliverables. Visits to the companies and informal sessions during the steering committees could leverage informal mechanisms of knowledge exchange and social control to increase mutual understanding within the project.Despite the novel insights gained from this research, the study is not free of limitations. First, even if the qualitative methodology extends the previous knowledge on the dynamics on traditional SME engagement in collaborative innovation, a mixed method could further enrich the results by combining analytical and statistical approaches. Second, this study developed its analysis over time along the whole duration of the projects, from the beginning to the end. However, it would be interesting to monitor SMEs over time after the end of the project as well. For example, SMEs should be stimulated and incentivised to participate in smart city projects where a city’s ecosystems of partners and the collaborations between them are critical for innovation and where entrepreneurships and project level barriers are common (Scuotto et al.


The current research trend for excellent miscibility in polymer mixing is the use of plasticizers. The use of most plasticizers usually has some negative effects on the mechanical properties of the resulting composite and can sometimes make it toxic, which makes such polymers unsuitable for biomedical applications. This research focuses on the improvement of the miscibility of polymer composites using two-step mixing with a rheomixer and a mix extruder. Polylactic acid (PLA), chitin, and starch were produced after two-step mixing, using a compression molding method with decreasing composition variation (between 8% to 2%) of chitin and increasing starch content. A dynamic mechanical analysis (DMA) was used to study the mechanical behavior of the composite at various temperatures. The tensile strength, yield, elastic modulus, impact, morphology, and compatibility properties were also studied. The DMA results showed a glass transition temperature range of 50 °C to 100 °C for all samples, with a distinct peak value for the loss modulus and factor. The single distinct peak value meant the polymer blend was compatible. The storage and loss modulus increased with an increase in blending, while the loss factor decreased, indicating excellent compatibility and miscibility of the composite components. The mechanical properties of the samples improved compared to neat PLA. Small voids and immiscibility were noticed in the scanning electron microscopy images, and this was corroborated by X-ray diffraction graphs that showed an improvement in the crystalline nature of PLA with starch. Bioabsorption and toxicity tests showed compatibility with the rat system, which is similar to the human system. Biomaterials are used in tissue repair, and the need for these materials is increasing globally. Tissue replacement is commonly used in orthopedics for fractures, including femur, humerus, and bone socket fractures ,2,3. TheThe use of a natural polymer as an implant material has various challenges, of which mechanical and degradation properties are of noticeable concern . To resoPolylactic acid is a polyester, biodegradable polymer from a starch source. It is one of the most consumed natural polymers in industrial applications. It is sourced from starch through a direct condensation process and has been used for several industrial manufacturing products, including packaging and biomedical implants. Polylactic acid has been reported to form a composite that enables the natural growth of cells in bone osteogenic differentiation . ProblemThe literature shows that much work has been done on PLA blending and reinforcement for improved mechanical properties ,12. The Chitin and starch are abundantly available for use ,17. TheyOn the basis of the reviewed literature, this study sought to find the combined effect of a chitin–starch blend on the mechanical and bioabsorption properties of PLA for biomedical applications. The combined use of PLA, chitin, and starch has not been reported in the literature (hence the novelty of the work).Rattus norvegicus: Wistar rats) were purchased from the Federal University of Technology, Akure, Nigeria.The materials were starch, chitin from crab bone, and polylactic acid. Heat-extrusion-grade 4032D PLA from NatureWorks  was used with a specific gravity of 1.24; a melt flow rate (MFR), in g/10 min , of 7; and a melt density (g/cc) of 1.08 at 230 °C. The melting temperature, tensile strength, modulus, yield strength, and elongation were 160 °C, 53.5 MPa, 3500 MPa, 60 MPa, and 6%, respectively. Practical-grade chitin (C) (particle size range of 0.50 mm to 0.01 mm) and corn starch (S) (particle size range of 0.50 mm to 0.01 mm) were supplied from Sigma Aldrich . Rats (The PLA pellets were ground into powder (particle size range of 0.71 mm to 0.045 mm) form using an AA-150 power granulator  and dried at 60 °C for 4 h with a dry air generator, the Luxor 50 . Chitin and starch of varying compositions in powdered form were mixed with a constant percentage of PLA variation using a Thermo Electronic Rheomixer 03 . The mixture was further mixed and extruded with a parallel c-rotating extruder Process 11 twin-screw extruder  at a temperature profile of 120 °C, 150 °C, 170 °C, 180 °C, 190 °C, 190 °C, and 200 °C and then quenched in water at room temperature. A feeding rate of 30 sets, a pressure of 35 bar, and a 183 °C melt zone were used for the extruding process. The composite sample filament was pelletized with a Thermo Scientific pelletizer  and pressed into characterization test shape using a Carver press compression molding machine  at 170 °C for 15 min at a pressure of 100 bar. The test samples were cooled in atmospheric air and stored in Ziploc bags. The composition variation in the current study was based on previous research. In their study, Nasrin et al.  reportedAn Instron universal testing machine, model 5966 , was used to test the tensile samples prepared at standard dimensions using a Carver press compression molding machine at 170 °C. The test standard used was ASTM D3039-14 (2014)  for poly2). A standard rectangularly shaped sample was used according to the standard.A Ceast Resil Impactor 7181 , Akron, OH, USA) was used for the test per standard ASTM D256-04 (2004) [A PerkinElmer dynamic mechanical analyzer (DMA) 8000  was used to analyze the mechanical behavior of the composite materials. The storage modulus (E’), loss modulus (E’’), and loss factor (Tan δ) were measured. A standard test method, ASTM D4065-06 (2006) , was useA field-emission scanning electron microscope (FE-SEM) JSM7500F  was used to observe the tensile fractured surface morphological properties of the polymer composite. The samples were coated with carbon to improve their conductivity for a visual image in the field-emission scanning electron microscope (SEM).Additionally, X-ray diffraction (XRD) analysis was performed to obtain the degree of crystallinity of the composite using PANalytical X’Pert PRO X-ray Diffraction (XRD). The X-ray Cu  radiation source had a wavelength of 1.540598 for K-alpha 1 and K-alpha 2, a scan range of 5–90, a generating voltage of 45 volts, and a tube current of 40 A.Ethical permission was approved by the ethical committee of the Federal University of Technology, Akure, through ethical number FUTA/ETH/007. Standard ethical procedures were adhered to in caring out the biotoxicity test. Female rats were used for the in vivo absorption test. The rats were marked for identification and put in different cages for 5 days before dosing to acclimate them to the environment. After this time, the samples were fed to rats for 14 days, and they were observed at 30-min interval for the first 4 h after every dosage to determine if the composite was bioabsorbable or fatal. The animals were weighed at the start of the experiment, and after 3, 6, 9, and 14 days.Of the group of five, two rats that were fed samples A3 (6% chitin) and A5 (6% starch), which contained high contents of chitin and starch, were selected for the test, and a third control rat was fed with standard feed. The rats were anesthetized to collect blood samples. After 14 days of extract administration, the animals were euthanized. Chloroform anesthesia was administered to the animals, and blood samples were collected into ethylenediaminetetraacetic acid (EDTA) bottles through cardiac puncture. The blood samples collected were tested for their red blood cell counts (RBCs), white blood cell counts (WBCs), hemoglobin (Hb) concentration, erythrocyte sedimentation rate (ESR), and packed cell volume (PCV) using the following materials: blood samples, microscope, glass slides, a Giemsa stain, capillary tubes, a spectrophotometer, a Leishman stain, EDTA bottles, and a hematocrit centrifuge.A histological examination was completed on the liver using the method of Palipoch and Punsawad . The livGraphs of the tensile strength, yield strength, and elastic modulus are shown in The value of the elastic modulus is essential to the mechanical strength of the materials used for bone tissue repair . CompareGenerally, the impact strength of neat PLA has been reported to increase with chitin and reduce with starch content above 10% due to incompatibility with PLA . MinimalThe results of the dynamic analysis at 1 Hz and 10 Hz are shown in A drastic drop in the storage modulus of samples is characteristic of an amorphous substance. The value of the storage modulus was generally higher than the loss modulus, which was an indication that the elastic nature of the polymer dominated the viscous nature. A drastic drop in the transition region corroborated the amorphous nature of the composite blend. Additionally, the curves had a single transition that showed the miscibility of the blended polymers. The miscibility of the blend could also be seen in the loss modulus and loss factor graph, which has a single peak and represents the glass transition temperature. The strength of the intermolecular forces of the molecules determined the value of the modulus in the glassy state. The value of the modulus was high, which showed that there was high strength and miscibility between the PLA, chitin, and starch. The graph of E” and the loss factor (tan ∂), which has a single peak for each of the composites, shows the characteristics of the glass transition temperature. The value of the midpoint of the peak in each of the loss factor curves e,f is thThe value of the loss factor was low compared to neat PLA, which was an indication of improved interfacial bonding e,f. The The freeze-fractured SEM surface morphologies of all blends are presented in The SEM images showed that blending chitin and starch with PLA e produceThe degree of crystallinity and an X-ray diffraction plot for all samples are shown in The results of the absorption of the composite samples (A1 to A5) are shown in A significant increase in the white blood cell count may mean the presence of a parasite or toxin . HoweverA change in the liver architecture under a light microscope is usually ascribed to tension in the liver caused by a parasite or toxic substance . Liver aStarch/chitin/PLA composites were successfully developed using a two-step pre-mix;The mechanical properties of the polymer composites increased significantly more than did those of the neat PLA. The mechanical properties of the composites were improved using this method (with varying starch/chitin/PLA percentages). Sample A3 (PLA/6% C/2% S) had optimal strength and a suitable combination of the blend. This material can be used for trabecular tissue repair or any tissue repair ;The brittleness of neat PLA was reduced with the addition of the blend in all of the samples;The DMA of the composites showed a good storage modulus for stiffness, reduced loss factor, and good miscibility. It also showed a single peak, which showed the compatibility of the polymer blend. The glass temperature from the loss factor peak showed that the material was not suitable for high-temperature biomedical applications;The composite, which was molded using a Carver press, showed a uniform distribution of the natural polymer blend in its physical appearance. The SEM images showed a network distribution of the chitin/starch blend in PLA. Though there were small voids, the images showed a homogenous blend of chitin/starch with PLA;The amorphous characteristics of neat PLA caused no significant change in the blend; andThe material was absorbable and nontoxic according to the results of the acute toxicity test. Thus, full clinical analyses are recommended.


Despite yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) high strength in dental restoration application, Zr- the framework has a low tendency to react chemically with cement which is the main reason of these restoration failures. The aim of this in vitro study was to evaluate the effect of Y-TZP coating by nanocomposite of silica and aluminosilicate according to the sol-gel dip-coating technique on the bond strength of resin cement to Y-TZP. 3) were prepared and sintered and assigned into 4 groups (n=10) for coating including control groupwithout any further surface treatment, sandblasted using 110μm alumina particles under 2.5 bar and tip distance of 10 mm, silica sol dip coating+calcination,aluminosilicate sol dip coating+ calcinations. To confirm chemical bonds of sol-gel covers, Fourier transforms infrared spectroscopy (FT-IR) technique was used.The surface of the sample was investigated by scanning electron microscopy (SEM), energy-dispersive spectroscopy detector (EDS) and x-ray diffraction (XRD) methods.Micro-shear bond strengths (µSBS) of zirconia-cement specimens were evaluated. Data were analyzed with a one-way ANOVA test in SPSS version 11.5 software with a confidence interval of 95%.  In this experimental study, Y-TZP blocks (10×10×3mmp> 0.05). µSBS of sandblasting, nano-silica, and nano-aluminosilicate specimens were significantly higher than control. µSBS of nano-silica was higher than other groups but no significantdifference was observed in µSBS of sandblasting nano-silica, and nano-aluminosilicate groups ( Covering the zirconia surface with non-invasive nano-silica and nano-aluminosilicate using the sol-gel technique leads to improved cement bond strength. Surface preparation of zirconia-based dental restoration for resin bonding is still being considered as a major challenge. Unlike feldspathic porcelain and glass-ceramics,zirconia cannot be etched by hydrofluoric acid because its structure is completely made of crystalline phase and no glassy matrix exists. Therefore, a method other than acidetching must be used to provide microstructures for creating micromechanical adhesion or chemical bonding to improve the zirconia-resin bonding. So far, many researchers have examined different methods for creating zirconia surface roughness and improving zirconia-resin bonding  - 5. VaDifferent methods have been developed for silica coating on the zirconia surface, including silica pyrolytic coating, tribochemical coating, and plasma spraying techniques,Silano-Pen treatment, vapor-phase deposition, and coating using sol-gel methods  - 20.According to reports on silica coating techniques, tribochemical is preferred due to improved bonding and ease of application. In the tribochemical coating technique,the bonding surface is air-abraded with silica-coated alumina particles. Aluminum oxide particles sprinkled with silica are buried on the ceramic surface by air pressureleading to a more chemically reactive surface to the resin. This method not only provides the silica surface for silanization but also causes micromechanical retention.However, literature shows that sandblasting with silica-coated alumina particles causes stress on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) due to a decreasein degradation temperature of zirconia while the tetragonal phase transforms to monoclinic form  - 26.In our previous study, we have reported the sol-gel dip coating method as a gentle, while the effective procedure for the formation of silicate and aluminosilicatethin films directly from the solution on the dental zirconia substrate to improve the bond strength of zirconia to the porcelain. To evaluate the coating characterization,Fourier transforms infrared spectroscopy (FT-IR), x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy detector (EDS) tests were used.The analysis of these tests confirmed the creation of a smooth and uniform layer of nanocomposite on the zirconia surface that improved the mechanical feature of thezirconia–porcelain bond after porcelain firing  .In this study, silica and aluminosilicate have been used through the dip coating sol-gel method for zirconia coating to improve the bond strength of zirconia to resin cement.The null hypothesis tested was that the coating of Y-TZP surface functionalization by different coatings has no effect on the resin-zirconia bond strength.Forty Y-TZP blocks (10×10×3mm3) were prepared  and sintered as instructed by the manufacturer.The sintered blocks were assigned into 4 groups (n=10) for subsequent coating including the control group without any further surface treatment,sandblasted using 110μm alumina particles under 2.5 bar and tip distance of 10mm, silica sol dip coating+calcination and aluminosilicate sol dip coating+calcinations.The compositions and manufacturers of materials used in this study are listed in To provide a clean surface before coating, the blocks were washed under running distilled water, placed in an acetone/ethanol ultrasonic bath (Elmasonic S 300 H)for 20 minutes, and then air-dried at 70°C in Chamber Furnace - ELF11/6  . The silica sol was prepared as described previously  . TetraeThe Y-TZP blocks were coated by the sol using a dip-coating device and calcinated at 400°C (5°C/min) for 2 hours. The upward and downward motionspeed was 80 mm/s and the dipping time was 60 seconds  . SEM, EFT-IR, XRD, SEM and EDS were used to characterize the coating and the nature of the bonding between the coating and zirconia. The methods of thesetests which we used in this study described in our previous article completely  .2 intensity and 430-480 wavelength, for 40 seconds and stored in distilled water for 24 hours. The µSBS was tested with a universaltesting machine instrument  with a crosshead speed of 1mm/ min  were thoroughlymixed according to the manufacturer instructions and applied on the Y-TZP block with a special brush. After placement, the whole surface was gently driedwith oil- and water-free air spray. The resin cement pastes  were mixed in a weight ratio of 1/1 and placed inside theTygon tube with an internal diameter of 0.8mm and a height of 2mm. the Tygon tube was filled with cement and placed on the block, which was applied bycoupling agent and primer. Then the excess cement was removed and the surface was exposed to LED curing light  in alldirections by 1000 mW/cm1mm/ min .The statistical results were analyzed using the one-way ANOVA test, which was followed by Tukey's post hoc pairwise comparison (α₌0.05) using SPSS V11.5 software.The results of the analysis of the FT-IR, XRD, SEM, and EDS tests are explained in our previous study  . The results of the µSBS test for each study group are shown in The use of zirconia as a core in dental crowns improves fixed prosthesis due to high strength, tissue compatibility, and beauty.However, one of the main disadvantages of the Zirconia framework is the low tendency to react chemically with cement and thereby its weak bond. Thus, various techniques and materials have been used for improving the bond between zirconia and resin cement  . The aiIn this study, the results showed that the µSBS of the sandblasted samples and those coated with silica and aluminosilicate by sol-gel dip coating method was significantly higher than the control group. Therefore, the null hypothesis that there is no influence of Y-TZP surface treatment with sol-gel dip coating on the resin bond strength to Y-TZP is rejected. In the sol-gel dip coating method, the sol is first placed on the sample. Then, the solvent evaporates and nano-silica and nano-aluminosilicate gels are bonded to the zirconia surface through Van der Waals electrostatic forces. Finally, Si-O-Si bonds in silica and Al-O-Si bonds in aluminosilicate are reinforced by heat treatment and a solid layer binds to the surface. Then, hydroxyl groups  in silica or aluminosilicate coated samples increase the surface polarity and reactivity of chemical bonds with other chemicals  . This r The self-adhesive luting cement  used in this study is an MDP-based silane containing resin cement. Previous studies showed that these characteristics have improved the bonding between resin cement and neutral surfaces like zirconia and alumina core surface or silica-based surface due to silanization  - 33. Tet al. [ One of the common methods used to create micromechanical retention on the surface and increase bond strength is sandblasting with alumina powder. According to the results, sandblasting increases the bond strength of resin to zirconia. This increase can be due to micromechanical retention and the bond of hydroxyl groups of alumina and MDP monomer of resin cement  . Jevinket al.   also uset al.  - 25. Set al.  .et al. [ et al. [ et al. [ According to Chen C et al.  , cement et al.   found t et al.   as theyVarious studies show the reasonable performance of the sol-gel method in creating a layer of nano-silica. In our study, a silica or aluminosilicate network forms, through hydrolysis and polycondensation reaction. On the other hand, existing Si-OH and Al-OH have the potential to create a chemical bond to resin. As another advantage, in the sol-gel method, less working space and cheaper chemicals are used in comparison to expensive machines used for sandblasting. et al. [ et al. [ et al. [ So far, the silica sol-gel coating technique been used to increase the bond strength to zirconia. This is the first study in which aluminosilicate particles are coated on the surface by a sol-gel dip coating method. According to literature, the zirconia surface has been mainly coated with nano-alumina. Külünk T et al.   found n et al.   and Zha et al.   found aAccording to the results of the present study, the use of nano-silica and aluminosilicate coatings on zirconia can increase the µSBS of resin cement to zirconia. Therefore, methods other than a mechanical procedure like thribochemical coating technique, which may have long destructive effects on the zirconia- resin cement bonding, could be used.


S. mutans viability, and optical properties of zirconia. Dental zirconia blocks were sintered and randomly distributed into seven experimental groups: F0–F6. Except for F0, which only went through sintering, the additive firing was performed in order for F1–F6. Surface roughness, contact angle, S. mutans viability by fluorescence, and translucency parameter were measured. They were all highest after sintering (F0) and decreased after additive firings (F1–F6). The additive firing of zirconia after sintering decreased surface roughness, contact angle, S. mutans viability, and translucency. The number of firings after the first firing was not found to be critical in surface characteristics, S. mutans viability, and optical property. Changes in surface characteristics might have led to a decrease in S. mutans viability, while the change of translucency was not clinically significant. This implies that additive firing may prevent secondary caries under zirconia restorations, not compromising esthetic appearance.The purpose of this study was to observe whether the repetitive firing of dental zirconia caused changes in surface characteristics,  Dental zirconia has been widely used for esthetic prostheses that required high physical properties due to its superior mechanical properties and chemical stability compared to conventional ceramic materials ,2,3. It The method of using zirconia for tooth restoration can be divided into two categories. One is its use as a core material; ceramic material is then fabricated on the top of zirconia in a bilayer form . Due to the optical impermeability of zirconia, it is covered with veneering porcelain. Feldspar is mainly used to reproduce the esthetic characteristics of natural teeth. The veneering process of placing ceramics on the zirconia surface generally requires five stages of firings (750–900 °C) Another method is a pre-colored dental zirconia block that overcomes the porcelain chipping, which is the biggest drawback of PFZ. Zirconia is manufactured and used in a crown shape without ceramic material . However, the colored zirconia blocks are also insufficient to reproduce the colors of various teeth, so additional coloring or firing in the dental laboratory is required. Therefore, additive firing is one of the essential parts in the fabrication of dental zirconia prostheses.Firing process and its effect on properties of zirconia are not fully understood, but there have been several reports on the negative effects of firing. Although the additive firing temperature was lower than the sintering temperature of the core material, it decreased the flexural strength and microhardness of zirconia . In addiSurface characteristics such as surface roughness and contact angle are closely related ,11. TheiS. mutans plays a main role [S. mutans adhesion might be important, so there has been research on adhesion of S. mutans on zirconia [S. mutans adhesion, reduction in surface roughness and hydrophobicity has been found to be successful [Analysis of surface roughness and contact angle in terms of biofilm accumulation is also important since they affect microbial adhesion to induce biofilm formation ,18,19. Iain role . For suczirconia ,28. To pccessful ,30. HoweS. mutans viability, and translucency. In addition, those characteristics have not been integrated to suggest clinical relevance. Therefore, the purpose of this study was to observe whether the repetitive firing of dental zirconia caused changes in surface characteristics, S. mutans viability, and optical property of zirconia and to discuss the importance of them in clinical perspective.Despite the importance and advantage of firing in zirconia, its effect has not been clearly identified in relation to surface roughness, contact angle, Dental zirconia blocks  were cut and finished by a low-speed diamond disc . They were then sintered, up to 1450 °C, according to the manufacturer’s instructions. The specimens were randomly distributed into seven experimental groups: F0 , F1 ), F2 (second additive firing (Margin)), F3 (third additive firing (Wash)), F4 (fourth additive firing (Dentin and Enamel)), F5 (fifth additive firing (Stain)), and F6 (sixth additive firing (Glazing)); n = 7 each. Except for F0, which only went through sintering, the additive firing was performed for F1–F6 according to the manufacturer’s instructions . They weFor all the groups (F0–F6), surface roughness was measured by confocal laser scanning microscopy (CLSM)  at 20 × objective to obtain the image field of 500 × 500 μm. High pass filter cut-off (Streptococcus mutans (UA159) was cultured in Brain Heart Infusion Broth  at 37 °C of 100% relative humidity. Zirconia specimens were prepared by ultrasonication with ethanol and distilled water. Then S. mutans (OD600 = 0.5) was cultured over the prepared specimen for 24 h. S. mutans was treated by bacterial viability kit  for 15 min to be observed under CLSM . Based on the images, the area fraction of the fluorescent cells was calculated with computer software .*a*b* values  were measured at the center of each specimen over a black (B) and white (W) background using a spectrophotometer . Then the TP values were calculated by the following equation:The translucency was measured using the translucency parameter (TP)  with thrSurface roughness, contact angle, and translucency parameters were analyzed by a nonparametric Kruskal–Wallis test and Mann–Whitney test with Bonferroni correction as they failed the normality test. All statistical analyses were performed with a significance level of 0.05 using SPSS statistics for Windows .The surface roughness measured as mean height (Sa) was the highest  μm) immediately after sintering , and the roughness decreased to 0.07  μm after the first firing (F1). Second firing (F2)  μm), third firing (F3)  μm), fourth firing (F4)  μm), fifth firing (F5)  μm), and sixth firing (F6)  μm) also decreased the surface roughness compared to F0. For the arithmetic mean roughness of profile (Ra), maximum height of surface (Sz), and maximum pit height of surface (Sv), the same trend as in mean height (Sa) was observed . Moreovep < 0.05).The contact angle was 53.13 ± 0.82° in F0, and it decreased to 21.83 ± 0.97° in F1 and to 14.75 ± 0.84° in F2. In F3–F6, the contact angle was less than 10°, indicating their hydrophilic properties . There wS. mutans, observed with CLSM was the highest in F0 (7.66%), and it decreased to 1.47% (F1), 1.02% (F2), 0.88% (F3), 0.66% (F4), 0.92% (F5), and 0.85% (F6). Its decrease was visualized as a series of fluorescence images  compared to F0. It was 5.05 in F0 and decreased to 4.39 (F1), 4.21 (F2), 4.43 (F3), 4.66 (F4), 4.53 (F5), and 4.79 (F6) .Dental zirconia undergoes additive firing during the veneering process for esthetic purposes, and their physical properties may change during the process. It was reported that the veneering process reduced mechanical properties such as flexural strength, microhardness , and bonS. mutans viability, so it was consistent with the previous studies. The significance of this study was that such phenomenon was reproduced by repeated firings. Increased roughness and the following hydrophobicity are also well-known [For the bacteria, on the other hand, increased roughness induces their adhesion due to irregularities and increased surface area . This phll-known . Typicalll-known , but theTo analyze the surface roughness both on a profile and surface, profile roughness parameter (Ra) and areal roughness parameters  were taken. Although Ra could provide the arithmetic mean of the roughness on a profile, it only measures 2D roughness. To include 3D information about the roughness, the areal parameters were additionally used in the study . First, The contact angle was significantly reduced after the first and second firing (F1 and F2), and it was consistently smaller than 10° in the following firing. This might be explained in relation to the physicochemistry alteration of the surface. Although there have been no explicit results about the effect of firing, numerous approaches, including oxygen plasma and ultraviolet treatment, were known to induce hydrophilicity by removal of hydrocarbons and insertion of polar groups on the surface . As the S. mutans forms a biofilm on the tooth surface and demineralizes it, causing dental caries [S. mutans viability to inhibit biofilm formation is important in preventing dental caries. After firing zirconia in this study, the viability of S. mutans was reduced in all stages (F1–F6), which can be said to be a clinical advantage. However, although S. mutans is one of the major players in biofilm formation, it is not the only one. Other microorganisms such as F. nucleatum, P. gingivalis, and S. sanguinis are also involved in biofilm formation [Among the various types of bacteria residing in the oral cavity, l caries . Reducinormation . Thus, mS. mutans viability, as previously discussed, are achieved not affecting translucency.Multiple firings bring changes in color and translucency due to alterations in crystalline structure and surface specifications ,46. The The physical changes by multiple firing of zirconia and their potential advantages were discussed in this study. However, it may be necessary to investigate whether multiple firing could affect other factors such as longevity, structural stability, color, and marginal integrity that might influence the function of dental restorations. If there is a negative effect on those factors, the clinical importance of the presented results might be questioned. Thus, additional research that confirms the original function as dental restoration is needed. In addition, the effect of multiple firings without the presence of additives  might also be investigated to observe possible interfacial interaction. By doing so, it would allow more sophisticated control of the experimental conditions and improve the clinical significance of the current study.In a dental prosthesis, the veneering material covers most of the outer surface and core material, so two different materials can affect each other. Veneering ceramic increases the bulk thickness and may cause a change in the mechanical strength. According to one study, the cause of failure of the zirconia-based all-ceramic restorations occurred between the two interfaces or inside the veneer ceramic . Thus, tThis study focused on the phenomenon that took place on the surface. However, zirconia goes through phase transformation from tetragonal to monoclinic under stress , so struS. mutans viability to be used with grafting biomaterials to induce bone growth more efficiently [The reported characteristics of zirconia in the present study, if reinforced by further studies, might be applied to various clinical situations. For example, zirconia implants can go through firings for better hydrophilicity and less iciently ,58,59 oriciently ,61,62. Aiciently .S. mutans viability, and translucency. The number of firings after the first firing was not found to be critical in surface characteristics, S. mutans viability, and optical property. Changes in surface characteristics might have led to decrease in S. mutans viability, while the change of translucency was not clinically significant. This study, if reinforced by further research on microbial viability, implies that additive firing may prevent secondary caries under zirconia restorations, not compromising esthetic appearance.The additive firing of zirconia after sintering decreased surface roughness, contact angle,


Furthermore, they apologize to the readership of the Journal for any inconvenience caused.The revised version of


Pancreatic cancer has a poor prognosis with a 5-year survival of approximately 7%.5In this international EURECCA studyAlthough the quantity and quality of randomized clinical trials is increasing


Treatment of severe spinal deformities associated with neurofibromatosis has proven to be challenging. An 11-year-old girl, with neurofibromatosis and severe cervicothoracic kyphoscoliosis, was initially treated with posterior instrumentation and fusion. Implant failure developed within a year, requiring an anterior stabilisation and fusion with a non-vascularised fibular strut graft for better stability and increased likelihood of achieving union. The posterior instrumentation was removed due to its prominence and wound breakdown. Following the removal of the posterior implant, the fibular graft fractured. The patient was maintained on a cervical collar until union was achieved. Posterior spinal fusion alone in severe spinal deformities in neurofibromatosis has a high risk of failure. A combined anterior and posterior fusion may increase the chance of success, with better stability and union rate. Correcting the dystrophic curve has proven to be challenging due to the high rate of failure and pseudarthrosis3. Literature has recommended using both anterior and posterior fusion in a severe dystrophic curve to increase the chance of success4. Utilising fibula strut graft as anterior support in the correction of spinal deformities has been well reported. However, there is a risk of graft fracture. A newer technique of using vascularised fibula graft may have a higher rate of an union, but it was found to be technically more demanding5.Spinal deformities are often reported in neurofibromatosis patients and can be of dystrophic or non-dystrophic typeAn 11-year-old girl, with neurofibromatosis, first noticed a spinal deformity at the age of 7 and was diagnosed with severe cervicothoracic kyphoscoliosis. She defaulted follow-up and presented to us four years later with worsening of the spinal deformity associated with neurological deficit. She had bilateral weakness of the lower limbs with diminished sensation from the level of C5 and below. Computerised tomographic and magnetic resonance imaging showed that she had severe cervicothoracic kyphoscoliosis and ductal ectasia from C7 to T3 level. Posterior instrumentation and fusion in situ from C5 to T12 levels with decompression was performed  A year aWe proceeded with anterior cervicothoracic stabilisation, approaching via bilateral manubrio-sternotomy . A fibulTwo years later, she developed wound breakdown over the posterior thoracic region due to the prominence of the implant. The posterior instrumentation was subsequently removed to promote wound healing. However, two months after the removal of the posterior instrumentation, the fibula graft fractured as the spinal fusion had not been completed fully . She wasShe was followed up for more than six years since complete fusion occurred and was last seen six months ago with no new complaint. Recent radiographs showed no further progression of deformity . She had1.In neurofibromatosis, the spinal deformities could be classified into dystrophic or non-dystrophic. Dystrophic changes included rib “pencilling”, spindling of the transverse process, scalloping of vertebral bodies, foraminal enlargement and paravertebral soft tissue tumour. Dystrophic scoliosis in neurofibromatosis often was a short-segment angular curve over the thoracic region with primary involvement of five or fewer vertebrae. The more severe dystrophic changes in the vertebral bodies were associated with a more rapid deterioration of curve, whereas the non-dystrophic spinal deformities behaved like those without neurofibromatosis3. Rate of pseudoarthrosis in posterior spinal fusion alone in dystrophic scoliosis was reported high from 38-60%4 Crawford recommended anterior disc excision and bone graft followed by posterior arthrodesis with instrumentation if the scoliotic curve was more than 80° or when there was a kyphosis of more than 50°2. Other authors recommended both anterior and posterior spinal fusion when kyphosis was more than 95°, or the apical vertebra was at a level below T83.Most literature advocated for both anterior and posterior fusion in severe dystrophic scoliosis4. There was an average progression of the curve of 12.7° in posterior fusion, and more than one procedure was required to achieve solid posterior fusion4. Even with combined anterior and posterior fusion in dystrophic scoliosis, there was still a failure rate of 7.5%2.The failure rate of posterior fusion alone in dystrophic kyphotic curves of 50° or more was 64% -72%5.Anterior strut graft had been used as anterior support in the treatment of spinal kyphosis, using either the fibula or the rib. However, in non-vascularised bone graft, osteocytes in the strut graft died immediately when implanted. The resorption process weakened the graft resulting in a higher risk of fracture. Vascularised fibula graft was reported with better mechanical properties with preservation of viable osteocytes, resulting in an earlier bone union, better biomechanical strength and stiffness. In Streitz’s series of 16 patients using vascularised fibular strut graft for anterior spinal fusion in spinal kyphosis, all cases achieved union in three to eight months with no reported graft fractureIn our patient, the initial posterior only instrumentation and fusion failed. We subsequently performed anterior cervicothoracic stabilisation with fibula strut graft but were still unable to achieve spinal fusion as the posterior instrumentation had to be removed early due to wound breakdown.We are highlighting this case for the difficulty in managing severe dystrophic scoliosis and stressing the importance of both anterior and posterior stabilisation for better fusion.


The effect of chronic patellar tendinopathy on tissue function and integrity is currently unclear and underinvestigated. The aim of this cohort comparison was to examine morphological, material, and mechanical properties of the patellar tendon and to extend earlier findings by measuring the ability to store and return elastic energy in symptomatic tendons.Seventeen patients with chronic , inferior pole patellar tendinopathy  were carefully matched to controls (25 ± 3 years) for training status, pattern, and history of loading of the patellar tendon. Individual knee extension force, patellar tendon stiffness, stress, strain, Young’s modulus, hysteresis, and energy storage capacity, were obtained with combined dynamometry, ultrasonography, magnetic resonance imaging, and electromyography.p = 0.216; d < −0.31) nor in tensile tendon force produced during isometric ramp contractions . Similarly, tendon strain , hysteresis , and strain energy storage  did not differ between groups. However, patellar tendon stiffness , stress  and Young’s modulus  were significantly lower in tendinopathic patients compared to healthy controls.Anthropometric parameters did not differ between groups. VISA-P scores ranged from 28 to 78 points, and symptoms had lasted from 10 to 120 months before testing. Tendon proximal cross-sectional area was 61% larger in the patellar tendinopathy group than in the control group. There were no differences between groups in maximal voluntary isometric knee extension torque (In this study, we observed lower stiffness in affected tendons. However, despite the substantial structural and histological changes occurring with tendinopathy, the tendon capacity to store and dissipate energy did not differ significantly. Tendinopathy is a multifactorial tissue disorder  responsiIn vivo measures on tendinopathic patellar tendons currently indicate either a deficit  on this topic, additional research is required to elucidate whether tendinopathy alters the stiffness of the patellar tendon, as suggested by alterations in extracellular matrix composition and by certain studies on patellar  of the affected region, but a decreased elastic modulus when compared to asymptomatic, healthy control tendons. Based on the limited evidence, we hypothesized that the chronic patellar tendinopathy of the inferior pole would not meaningfully effect tensile tissue strain and stiffness. Given the complexity of histological changes associated with tendinopathy and in the absence of previous data to specify this hypothesis, the purpose of this exploratory study was also to determine whether hysteresis would be lower or higher with this disorder.n = 13, male = 10; female 3) and/or non-tendon-like phenotypes, including bone formation or heterotopic ossification  at the proximal tendon region only  at the Department of Sport and Exercise Science. In patients suffering from chronic patellar tendinopathy, lower leg strength and tendon properties were estimated in the leg of the pathology, or that leg of the most severely affected tissue disorder. In the healthy matched case-control subject, leg selection was based on leg dominance  of the p1. Tissue length was defined as the distance between the tibial insertion and the apex of the patella. Mean patellar tendon CSA was obtained as the average of three separate measures performed at the proximal (pCSA) and distal (dCSA) insertion and at tendon mid-length (mCSA). Analyses were conducted by the same orthopaedist (YS). The reliability of MRI-based measurements of patellar tendon CSA has been reported in previous publications , and analyzed offline using an image-processing program ications .–1 at a cadence of ∼70 rpm on a stationary ergometer . The rotational center of the isokinetic dynamometer arm  was carefully aligned with the rotation axis of the knee joint. Subjects sliding was minimized by means of firm securing with adjustable shoulder pads, hip and footplate straps. Hip and knee joint angles were set to 75° and 90° (0° corresponding to full extension) throughout all test procedures . Tensile tendon force was calculated offline as the difference between the net extension torque and the torque produced by antagonist’s muscles, divided by the patellar tendon moment arm, which was based on a function of upper segment leg length , with a gradual but continuous ∼2-s build-up period and a 3-s plateau. The trial yielding the highest peak torque was retained for analysis. Three additional MIVCs were performed at a rate of 50 Nm⋅sg length . Antagong length . To thisg length . This teg length .80%). The targeted and produced torque were displayed on visual feedback, and several practice trials were performed for familiarization and tendon preconditioning . Dynamometer signals and sEMG data were collected at a sampling rate of 2000 Hz, and all data records were synchronized from sending an electrical pulse grabbed simultaneously by the dynamometer and ultrasound system . Force-deformation and stress-strain slopes were fitted using a constrained least-square function  sagittal over the patellar tendon. Scans were then analyzed offline by an experienced investigator (H-P.W) as the displacement between the patella apex and the tibial anterosuperior aspect using a semi-automatic video analysis software . The effect size (d) was defined as small for d> 0.2, medium for d> 0.5, and large for d> 0.8 . Two-tailed paired-samples r d> 0.8 . Pearsonn = 12), volleyball (n = 8), team handball (n = 4), skiing (n = 4), high level of long-distance running (n = 2), American football (n = 2), and recreational activities (n = 2). In line with activity background and volume, anthropometric parameters did not differ between groups. VISA-P and VAS scores ranged from 28 to 78 and 3.0 to 9.5 points, respectively, and symptoms had lasted from 10 to 120 months before the examination , stiffness measured to individual  or highest common force levels , Young’s modulus , hysteresis , or VISA-P scores .Since athletic activity background and volume were used as matching criteria, all pairs of case and control practiced the same sport, at the same national or international level, for a similar number of years and according to comparable weekly volumes. Patients and controls had thus loaded their patellar tendon according to comparable functional requirements. Athletic activity included football  = 4.98, p< 0.001, d = 1.21), medial  = 3.51, p = 0.003, d = 0.85), and distal tissue site  = 2.80, p = 0.013, d = 0.68)  .There was no difference in maximal knee extension torque or patellar tendon peak force when testing tendon mechanical properties. Patellar tendon stiffness did not differ between groups when measured at the greatest common force level. However, when measured at the individual highest force level, patellar tendon stiffness was lower (−18%) in the tendinopathic group compared to controls. Additionally, patellar tendon stress (−27%) and absolute and relative Young’s modulus (−32 and −33%) were significantly lower in tendinopathic patients compared to controls, but there was no difference in tendon strain . PatellaDespite the substantial structural and histological changes occurring with tendinopathy  energy dPatient reports of VISA-P and VAS scores  are consmax) and a lower Young’s modulus. Contrasting differences in tissue size and stiffness between tendinopathic and healthy patellar tendons had been previously observed by Consistent with previous observations, the greater tendon size was not reflected in higher stiffness values, but chronically diseased tendons exhibited a lower stiffness in high loading conditions  are common features of various mammalian tendons  and makeurements  and coulurements , metabolurements , and anaurements  featuresThe significant correlations found between VISA-P scores and the differences in proximal CSA, stiffness and Young’s modulus  of affecThe comparison of case-control pairs of symptomatic and pain-free, visually asymptomatic patellar tendons confirmed morphological differences and indicated differences in certain mechanical and material properties. Tendinophatic patellar tendons were characterized by a much larger thickness but a lower stiffness (and consequently a lower Young’s modulus) at maximal individual force. On the other hand, analyses of the loading and unloading curves suggest that elastic energy storage and dissipation capacities remain similar in tendinopathic and healthy subjects. Besides, the significant correlations found between the functional severity of the pathology (VISA-P) and mechanical and material patellar tendon properties  calls foin vivo, and the quantitative nature of the EMG-strength relationship remains a topic of scientific debate. Despite these potential validation limits, it is unlikely that differences in coactivation have influenced our findings. Similar ratios of antagonist-to-measured knee extension torque in tendinopathic (11.2%) and healthy subjects (10.1%) support this assumption. Finally, tendon provides viscoelastic behavior, and tissue property acquisitions potentially differ during dynamic, real-life situations (in vivo. Moreover, it seems a fair assumption that tendon properties calculated during isometric ramp contractions would be related to their measurements under different contractile conditions. Therefore, this standardized procedure seems valid and does not mitigate our initial conclusions.Potential limitations should be considered before concluding. First, some of the subjects suffered from patellar tendon disorders substantially longer than others . Althougtuations . HoweverThe datasets generated for this study are available on request to the corresponding author.The studies involving human participants were reviewed and approved by the German register for clinical trials: DRKS00011338 Local Research Ethics Committee: 415-E/2012/11-2016. The patients/participants provided their written informed consent to participate in this study.H-PW, OS, AK, EM, and FR contributed to the conceptualization of the study, and the review and editing of the writing. H-PW contributed to the methodology, the writing – original draft visualization, and the supervision. H-PW and FR contributed to the investigation and the project administration. H-PW contributed to the data analysis. FR, H-PW, and OS contributed to the funding acquisition. All authors read and approved the content of the final manuscript.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.