Graft construct elongation after pre-tensioning at 300 N was 12.8 mm (9.3 mm–16.5 mm) and mean cyclic elongation 0.4 mm (0.2 mm–0.9 mm), considered significant . The resistance and stiffness values were respectively 849.46 N (649.30 N-1027.90 N) and 221.49 N . Quadruple ST graft construct using two cortical buttons and adjustable loops showed a high stiffness and resistance with a very low elongation after cycling.The purpose of this study was to evaluate the biomechanical properties of a graft construct with quadrupled Semitendinosus and two cortical buttons with adjustable loops concerning elongation, stiffness and resistance. A total of 15 fresh human cadaveric semitendinosus tendons were quadrupled over the two adjustable loops and stitched at the tibial tip with a cerclage type suture. They underwent pre-tensioning at 300 N for 2 minutes followed by cyclic loading (1000 cycles between 50–250 N) and finally a load-to-failure test. Statistical analysis was performed using SPSS Statistics software and groups were compared using a paired t-test, with a significance level set at α This technique has the advantage of preserving the gracilis, potentially improving postoperative hamstring strength4, besides providing a larger diameter than ST-G graft.The most common preparation technique using hamstring is the doubled semitendinosus (ST) and gracilis tendons (G). However, to decrease the morbidity associated to hamstring harvesting, a quadrupled ST graft construct has been developed in the last few yearset al.5 published a new quadruple ST graft construct using two cortical button and adjustable loops. The purpose of this study was to evaluate its biomechanical properties.Recently, Silva It was hypothesized that this quadruple ST graft construct with double cortical suspension provides a higher stiffness and resistance fixation along with a lower elongation after cycling.The study, in compliance with the Helsinki Declaration, was approved by the institutional ethics committee , South Section and Board of Directors of the National Institute of Legal Medicine and Forensic Sciences. It was confirmed that all the cadaver bodies used, were not included in the National Register of Non Donors (RENNDA form), which avoids the need for informed consent form.A total of 15 fresh human cadaver semitendinosus tendons were harvested (age: 21–62) at the first 36 hours after death time.Grafts were wrapped in a wet dressing (NaCl 0.9%) on sterile boxes, stored at 10 °C while waiting for the biomechanical analysis, performed up to one hour after harvesting. Tendons length was defined as 240 mm in order to achieve a constant folded graft length of approximately 60 mm.5.Both free ends of the semitendinosus were stitched over a length of 30 mm, using No. 2 ExpressBraid™ suture . Two adjustable-length loop cortical button devices were used: ToggleLoc™ , for the femur, and ToggleLoc XL Inline™ , for the tibia. The tendon graft was symmetrically folded over the tibial cortical button loop and the doubled graft was passed through the femoral cortical button loop and once again symmetrically folded. Both grafts free ends are tied together with 3 knots over the tibial button loop. Then, the same sutures are tied over the graft itself using 4 knots6.Finally, the graft is reinforced to the tibial side with a cerclage suture and a buried knotTo simulate the common tunnel lengths on the femur and tibia we assumed a constant femoral side length of 40 mm (including graft’s 15 mm) and a tibial side length of 50 mm (including graft’s 20 mm), adjusting both ToggleLoc™ loops, in order to achieve these values.Tests were conducted in a servo-hydraulic device (retrofitted Instron 8800 plus) with a loading cell of 10.0 kN (class 0.5). The graft construction ends (ToggleLoc™) were then placed in custom designed jigs which were rigidly fixed to the machine grips as shown in Fig. The test protocol consisted in several steps from pretensioning to tensile test until failure finally took place Table .Table 1T7. The elongation (millimeter) was determined as the difference between the displacement at a certain load and the initial load. For the load protocol, elongation during pre-tensioning (step 2) - Pre-tensioning elongation- and after 1000 cycles (step 5) - cycling elongation - were measured.Displacement and load were recorded by using the BlueHill Instron native softwarePre-tensioning elongation represents the construct tensioning in traction table before graft implantation and cycling elongation represents the construct elongation after graft fixation followed by 1000 gait cycles.A final tensile test (step 7) was done to evaluate both the ultimate load failure (ULF) and stiffness. Stiffness (N/mm) was then calculated as the load-elongation’s slope for the first part of the curve, i.e., until a load of 300 N. The final test set-up can be depicted in Fig. The mechanism of failure was recorded Fig. . = 0.05.Statistical analysis was performed using SPSS Statistics software, version 24 . The Shapiro–Wilk test was used to check whether the data had a normal distribution. Paired t-tests were used to compare groups of two values obtained by the same individuals in different circumstances. Data descriptions include means, 95% confidence intervals, standard deviations, first and third quartiles, median, maximum and minimum values. The significance level was set at α9.Test power calculation was obtained using R software (R Core Team (2017))The estimate of the correlation (ρ) between elongation after pre-tensioning at 300 N and after 1000 cycles, is given by the sample correlation (r) obtained from the sample, which was equal to 0.7.300 = σ1000 = σ where σ is estimated by the sample standard deviation s = 1.8 mm. We can then use the following expression to obtain the standard deviation for the differences (diff) in elongations between the pre-tensioning at 300 N and after 1000 cycles (Eq. Assuming that the standard deviations of each elongation (pre-tensioning at 300 N and after 1000 cycles) are equal, i.e., making the general assumption for the homogeneity of variance we consider that σdiff equal to 1.394 mm.Consequently, we obtain an estimate of σIn order to detect a difference of about 1 mm between elongations after 300 N and 1000 cycles, when using a sample of size 15 (n = 15) with 0.05 significance level and assuming that the standard deviation of the differences is 1.39 mm, the obtained power was 84%.(a)Mean quadruple ST graft final diameter was 9.7 mm (8–11 mm Table ).Table 2Mean total graft construct’s elongation after pre-tensioning at 300 N was 12.8 mm (SD: 1.59 (Table th cycle) was 0.44 mm (SD: 0.24), considered significant , comprising a confidence range between 0.31 and 0.57 mm  and 221.49 N/mm (SD:25.16), respectively Table .All failures occurred in the graft. In 13 out of 15, the rupture was at the femoral side folded graft Fig. . In the The most important finding of the present study was that a quadruple ST graft construct with two cortical suspension devices provided a higher stiffness and resistance fixation along with a lower elongation after cycling.Elongation of the ACL graft construct should be kept to a minimum in order to avoid postoperative laxity and the risk of early ACL reconstruction failure.10. However, the effect of this preparation method on graft elongation is so far not known.With the development of adjustable-length loop cortical button devices, a new graft preparation technique using a cortical button graft fixation for the femur and tibia was introduced as described previously11 to allow a better accommodation of all the interfaces  and thus avoiding a higher elongation after graft implantation. There is no consensus regarding how much load is actually needed for this pre-tensioning. Considering that the common walking loads acting on the graft are estimated to be around 298 N15, in the current study pre-tensioning was undertaken at 300 N load, in an attempt to reproduce physiological loads.Proper pre-tensioning of graft construct is of extreme importanceet al.16. After pre-tensioning under 50 N, the elongation obtained in three different quadruple ST graft constructs ranged in-between 1.6 mm and 2.1 mm. Similar findings were reported by Petre10 referring a 2.45 mm elongation after pre-conditioning between 10 and 50 N. However, the used loads in those studies were 30 to 6 times lower (10–50 N) than the ones we applied.The elongation of the graft construct at this stage was 12.8 mm substantially higher than the one mentioned by Mayr In fact, greater elongation after pre-tensioning under high loads and low elongation after cycling, proves the importance of pre-tensioning in this kind of graft construct.18.Another concern topic is elongation after cycling, corresponding to the elapsed time after graft implantation. Ideally, it should be lower than 3 mm difference (side to side), considered by some authors as the limit above which failure is usually due to laxityet al.16 cyclic elongation after 1000 cycles ranged between 6.1 mm and 7.0 mm whereas Petre et al.10, mentioned higher cyclic elongation values (3.34 mm) and similar data were described by Barrow et al.11. These results are clearly higher than the ones obtained in our study (0.4 mm), suggesting that elongation after cycling is dependent on the selected pre-tensioning loads.In the present study, cumulative cyclic displacement determined after 1000 cycles was 0.4 mm and lower than the previous published data. According to Mayr 16.Stiffness and ultimate load failure of the studied graft construct were also evaluated. All the tested 15 constructs had mean values of stiffness (221.49 N/mm) and ULF (849.46 N) comparable or slightly higher than those published in the literatureThere are several limitations to the current study.19. This fact leads to higher stresses on the graft bending points over the adjustable loops. However, peak loads used in this study were similar to the forces experienced by the ACL during early rehabilitation20.First, the axial direction of the applied load, differs from clinical conditionsin vivo” conditions where graft is permanently hydrated, increasing graft fragility and decreasing the ULF.Secondly, it was not possible to hydrate the graft at the bending points Fig. , in oppoin vitro study focuses solely on graft construct biomechanics and does not include any biological factors.Finally, it is important to emphasize that this Nonetheless, in this study, we used fresh human cadaver grafts, minimizing the bias that can be associated to frozen human or animal grafts.The clinical relevance of this study comes from the fact that this graft construct technique may allow a safe rehabilitation with a low risk of elongation.Quadruple ST graft construct using two cortical buttons with adjustable loops, showed a higher stiffness and resistance with a very low elongation after cycling.Pre-tensioning the graft construct under high loads, seems to prevent from additional significant displacement after cycling, assuming a critical role in its preparation.


Phaseolus vulgaris in comparison to the use of unmodified cellulose.The purpose of this work was to prepare new biodegradable starch-cellulose composites, with starch, using casein and gelatin as natural nutrients. The physico-chemical properties of the starch films and cellulose fabrics with starch coatings were studied by Fourier transformation infrared analysis, laser confocal scanning microscopy (LCSM), scanning electron microscopy (SEM), UV-Vis spectroscopy, swelling tests, mechanical tests, thermal analysis thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The susceptibility of the starch films to biodegradation was investigated, together with their resistance to thermo-oxidative aging. As a result of the formation of the starch films, both the casein and gelatin macromolecules were able to interact directly with the starch matrix and the fractions of unbranched amylose and branched amylopectin it contained. This interaction was visible as changes in the absorption bands of the polar groups, as revealed by infrared analysis. Spectral analysis of the cellulose fabrics coated with starch films suggests that hydrogen bridges formed between the micelles of long cellulose filaments and the micro and macro-fibers of the starch pectins. An applicative test revealed that when used as a covering for bean cultivation the cellulose-starch composites act as a fertilizing component, contributing to significantly improved growth of  The treatment of polymer waste has been recognized in recent decades as a major cause of environmental pollution. In agriculture, synthetic materials such as polymer mulches are applied to increase crop yields as well as to control weeds and pests. However, synthetic materials have a negative impact on the environment, due to their long degradation time. Therefore, there is increasing interest in the design and production of novel biodegradable composites from renewable resources ,3,4,5,6.Most films on the world market produced for agricultural applications are made of linear LLDPE (Linear Low-Density Polyethylene). Another important material is the EVA/EBA (ethylene-vinyl acetate EVA/ethylene-co-n-butyl acrylate EBA) copolymer, a combination of ethylene and vinyl acetate copolymer with built-in ethylene chains modified by butyl acrylate. The EVA/EBA copolymer is used to produce technical textiles, including garden foils. The copolymer is characterized by very good flexibility as well as chemical and thermal stability, making it a very desirable material ,8,9. AgrAlthough artificial fibers (such as polyolefins) are preferred to natural fibers for use in agro-textiles, due mainly to their better price/price ratio, low weight, high strength and long life, natural fibers can be used in some specific areas, where properties such as high moisture retention, wet strength, biodegradability are required . Jute, wStarch-type biopolymers, casein, gelatin, etc., seem promising materials for use in natural fibers. One such natural polymer is starch, which has many unique properties. Starch is a polysaccharide consisting of amylose and amylopectin. The ability to gelatinize is one of the most important properties of starch. In this process, the intermolecular bonds of starch molecules are broken down in the presence of water and heat. Many applications of starch rely on its ability to gelatinize and on its solubility or swelling power ,18,19,20The aim of the present study was to obtain and characterize starchy films and cellulose-starch composites (agro-textiles coated with the starch films). The starchy films were made by chemical modification of starch using gelatin or casein as the binder and coating–forming factors. Casein was chosen due to its film–forming properties and broad range of applications in food, textiles, adhesives, etc. and gelatin due to its gelling properties and the possibility of sol in the gel, as well as for its wide applications in the food industry, photography and industry pharmaceuticals ,28,29,30Starch SUPERIOR was obtained from Trzemeszno, Poland. Casein and gelatin were produced by Chemico, Białe Błota, Poland. Cellulose fabric was sourced from MATIMPEX PPHU, Lodz, Poland. Ammonia was obtained from Chempur, Piekary Śląskie, Poland. Glycerin was supplied by Chemico, Białe Błota, Poland.Mixtures were prepared according to the formulas presented in The process of preparing the mixture was based on gelatinization  of the respective weight fraction of starch , to whicStarch films with a thickness of 1 mm were obtained by pressing the starch mixture on a hydraulic press  b. The stAppropriate forms were cut from the fabric-coated compositions, in accordance with the applicable standards for the various test techniques. Immediately after their preparation, the starch mixtures were incubated under conditions of about 7 °C or directly formed in a hydraulic press.Importantly, during the production of the composites from natural raw materials the appearance of fungi or mold was noted on their surfaces. The appearance of microorganisms on the polymeric material was the result of storage for 3 days under standard room conditions and will be discussed in −1. The tensile strength (TSb) and percentage elongation at break (Eb) were determined.The mechanical properties of the prepared composites were tested using a Zwick universal testing machine model 1435  according to the PN-ISO 37:1998 standard with a preliminary force of 0.1 N and strain rate of 200 mm minHardness measurements were performed according to the PN-71/C-04238 standard. A SHORE C digital hardness meter  was used to test the coated fabrics and a SHORE A (pressure 12.5 N) to test the films . Measurements are made in accordance with the applicable standards: DIN EN ISO 868, DIN 53505, ASTM D 2240, ISO 7619, NFT 51-174, BS903 PART A 26. Hardness was determined before and after aging.The swelling index was determined using the equilibrium swelling method. This test was carried out according to the PN-ISO 1817:2011/Ap1:2002 standard. Specimens with an average mass of 30–40 mg were immersed in pure water. Measurements were carried out at room temperature (25 °C) for 2 days (48 h). After this time, the samples were removed from the immersion liquid to determine their weight change. The samples were washed with diethyl ether, then dried on filter paper and weighed. Next, the samples were dried in air for 7 days. They were then subjected to drying at a temperature of 50 °C for 96 h. Their weight stability was then tested by additional measurements. The swelling ratio was calculated according to the following Equation (1):b2—tensile strength [MPa] after thermal-oxidative aging; Eb2—elongation at break [%] after thermal-oxidative aging; TSb1—tensile strength [MPa] before thermal-oxidative aging; Eb1—elongation at break [%] before thermal-oxidative aging.Thermo-oxidative aging resistance was determined according to the PN-88/C-04207 standard. Samples were placed in a drier with an air circulation system . The samples were left for 7 days at a temperature of 70 °C. The tensile strength (TSb) and percentage elongation at break (Eb) were determined again. Based on TSb and Eb values, the ageing coefficient (A) was calculated from the Equation (2):−1 from 4000 to 600 cm−1 wavenumber, with a set resolution of 8 cm−1 and a scan number of 64. A confocal Keyence Laser Scanning Confocal Microscopy  system was used to acquire optical images in 3D with high resolution lenses: 220 μm × 50 μm; 220 μm × 100 μm and 2500 μm × 500 μm .The samples were characterized by means of Fourier Transformation Infrared (FTIR) spectroscopy using a Nicolet 6700  equipped with a Platinum ATR single reflection diamond, USA. Fifty scans were obtained at a resolution of 10 cmColor changes in the composites after incubation in universal soil were measured suing a CM-3600d UV-VIS spectrophotometer . The total color difference (∆E*) was evaluated from the range of changes, with higher ∆E* values indicating greater observed changes.Soil aging tests were carried out according to PN-EN ISO 846. Fittings in the form of paddles were placed in universal soil in a climatic chamber  for 15 days at 30 °C with relative humidity of air WWP = 80%.As a result of storage at room temperature (3 days), mold and similar microorganisms appeared on the surfaces of the starch films. The Institute of Microbiology at Lodz University of Technology investigated whether such fungi would appear under similar conditions on a composite material made of biopolymers, such as starch, gelatin or casein. Mold fungi chosen in accordance with PN-EN ISO 846 were used as test organisms. A mixture of the following mold fungus species was used: Aspergillus niger, Penicillum ochrochloron, Aspergillus terreus, Scopularopsis brevicaulis, Fuzarium, Rhizoctonia, Claviceps and Stachybotrys and Chaetomium globusum. Studies were also conducted on dermatophytes from the species Trichophyton mentagrophytes and actinomycetes of the genus Streptomyces. The strains were obtained from the Collection of Pure Cultures for Industrial Microbiology at the Institute of Fermentation and Microbiology Technology, PL, LOCK 105 .An optical microscope with digital imaging was used for 2D measurements in real time and for 3D imaging of surface topography .The surfaces of the obtained composites were assessed by SEM with a Bal-Tec SCD050 sputter coater and LEO 1530 produced by Bal-Tec .−1 in a stream of inert gas (argon) with a flow rate of 60 cm3 min−1 in a temperature range of 25–800 °C. The heat effect and the range of the glass transition temperature were determined by differential scanning calorimetry (DSC) in the temperature range of −80 to 150 °C, with a heating rate of 10 °C min−1.The thermal stability of the material was determined using a Mettler Toledo TGA/DSC  analyzer  calibrated using the standard pattern . The samples were heated at a heating rate of 10 °C minThe cellulose-starch composites were placed in containers containing soil with pH 5.5–6. Dwarf beans  were planted in the soil. Seeds were also planted in a container with no composite, as a control.°C in periods of 1 month, 3 months, half a year and 1.5 years. During the measurements, the composites were mechanically mixed and measured for the loss of mass. Structural changes in the composites were estimated organoleptically.Composting tests were conducted in a climatic chamber with a humidity of 80% and a temperature of 30 Analysis of the results was divided into two parts, the first relating to the properties of the starch films and the second focusing on the properties and possible applications of the cellulose fabrics covered with starch film.−1, and water absorption is higher for the SG75cg film than for SG75c, due to the gelatinizing properties of gelatin and greater hydrophilicity of the gelatin system. The OH groups are most visible in the cellulose spectrum. We therefore had the idea of coating cellulose with a starch-casein or starch-gelatin mixture to increase the hydrophilicity of the composite intended for the cultivation of plants. This would ensure greater water absorption and better maintenance of the plants during periods of drought.Interactions between the starch matrix and other components were evidenced by changes in the absorption bands on the transmission spectra obtained by FTIR . The ban−1 of the stretching vibrations of the –CH groups are visible, which, due to the introduction of either casein or the casein system with gelatin, were significantly shortened. This may indicate the creation of a common spatial network between the components of the composition during the cross-linking processes. The buildup of C=O bonds in the casein and gelatin sample (SG75cg) caused an increase in absorption band intensity in the range of 1500–1700 cm−1. The presence of bands attributed to the carbonyl and hydroxyl groups may be indicative of possible interactions in the lattice network between casein and gelatin macromolecules versus starch macromolecules. The starch films produced by thermal crosslinking in the presence of a plasticizer (glycerol) formed stable joints at elevated temperatures. New –OR groups were created at wavenumbers 1700 and 1100 cm−1, as shown in −1 was observed for the sample containing both casein and gelatin (SG75cg), as indicated by the occurrence of C–O bonding [The FTIR spectrum of the sample containing casein (SG75c) and casein/gelatin (SG75cg) shows the presence of –CH bonds. On the spectrum of both cellulose and starch, much more intense bands in the range of 3000–2800 cm bonding ,33,34,35Hardness (H) increased with increasing starch content relative to the glycerol plasticizer in the composites SG75, SG80 and SG85 . The stiThe results in It can be also seen that samples containing gelatin and casein exhibited the most significant changes in terms of the hardness parameter after soil tests (∆H). The introduction of gelatin and starch promotes the biodegradation process, as evidenced by greater changes in parameter ∆H as well as by composting tests. A larger proportion of plasticizer in starch films provides greater protection against color changes under a half-dozen different external factors, which is indicated by the dE*ab parameter. In addition, the SG75c and SG75cg samples may exhibit greater color protection, for example against UV radiation.The application of gelatin and casein as modifiers resulted in an increase in the hardness of starch films containing gelatin . Due to Non-crosslinked samples of the starch films were incubated at room temperature. This led to significant surface changes. Before thermal crosslinking, the samples the films were stored at room temperature for 3 days, not stored according to recommended practice in a thermal chamber at below 10 °C. This resulted in the formation of yellow-colored efflorescence as well as clusters of mold and fungi on their surfaces. Microbiological analysis carried out by the Microbiology Institute at Lodz University of Technology revealed that the surfaces were covered with dark green mycotoxin forms .The toxins were produced by fungi (mold) from the genera Aspergillus, Penicillium, Fusarium, Rhizoctonia, Claviceps and Stachybotrys. The optimal temperature at which mycotoxins form is between 20–25 °C. Mycotoxins include, among others, aflatoxins, ochratoxins (including ochratoxin A), patulin and aspergillose acid. For example, yellow, red and green blooms may suggest a type of Aspergillus, brown Cladosporium, black and gray Aspergillus niger, Alternaria, Rhizopus or Mucor .−1. The main differences seem to be in the fingerprint region at 3600–3200, 1650 cm−1 and 1200 cm−1. The FTIR spectra clearly indicate possible interactions occurring in the polysaccharide chains between starch and cellulose macromolecules  [The FTIR spectra of these samples show a strong absorption peak for the O–H stretching band centered around 3400 cmy casein . Typicalolecules b. The violecules a,b. Therles (−1) ,39,40.Based on the results of equilibrium swelling measurements, the swelling ratio of the studied composites decreased with increasing starch content . A reducThe composites with greater cross-link density appear to have more hydrogen bonds between their individual components, such as starch, gelatin and the glycerin system . This isThe composites produced by coating the agro-textile material with starch films were further analyzed in terms of their mechanical performance. Their tensile strength, elongation at break and hardness are given in The mechanical properties of all the cellulose-starch composites were significantly improved by the addition of the modifiers, casein or gelatin, while the difference in elongation at break was negligible. Gelatin caused a much greater improvement in mechanical properties. The increase in the mechanical properties of the SGg  composites may be attributed to the level of organization in the protein network ,41. CaseAs can be seen in We also studied the effect of starch and glycerin content as well as of the addition of casein or gelatin as modifiers on the thermo-oxidative aging resistance of the starch-based composites. The ageing coefficient values for the composites are presented in Surface analysis of the cellulose-starch composites was made using a confocal microscope with high accuracy and resolution, and also by SEM . Figure The application of the starch coating on the cellulose fabric was uniform. This is clearly visible in the images made with both the 220 × 50 and 2500 × 500 lenses . In a 10Similar observations can be made based on the SEM photos. 50 temperature loss of the sample mass is at a similar level in the case of degradation for the sample containing casein and gelatin biopolymers as in the SG75 composition . Differences were observed in the intensity of absorption bands from the groups –C=O, –OR and –OH. Increasing hardness values and sharper increases in water absorption during equilibrium swelling were also noted with respect to the native sample. The application of the films to natural cotton led to the formation of a stable structure between the gelatin or casein starch material and the cellulose base, as confirmed by confocal microscope analysis and SEM. This resulted in improved crosslink density, as shown by infrared spectral analysis, as well as more favorable mechanical properties. The starch composites produced, as shown in the thermal analysis of DTA, DSC, together with the addition of casein and gelatin, are characterized by a higher glass transition temperature Tg, greater rigidity, which is confirmed by the mechanical tests, hardness. The material should be stable for atmospheric conditions when used in crops. Similar observations have been made for cellulose-elastomeric material by Prochon and Tshela Ntumba . Starch


International Journal of Molecular Sciences have established the Best Paper Award to recognize the most outstanding articles published in the areas of molecular biology, molecular physics, and chemistry that have been published in the International Journal of Molecular Sciences. The prizes have been awarded annually since 2012 . Setting up standards and improving the characterization of EVs are our main goal and are important for any clinical approach. As we have treated an acute steroid-refractory Graft-versus-Host-Disease patient, we are aware of the complexity of MSC-EVs. In this context, we reviewed recently published in vivo models, which were treated with MSC-EVs. These disease models included rodent kidney, heart, liver, and brain injury models. A variety of different protocols for the production, characterization and application of MSC-EVs were used in these studies and are summarized in our article. The comparison of these studies revealed a lack of standardization, which is a broadly discussed issue in the field. Within this review, we point out the challenges and discuss possible solutions to build up standards for future studies .In case you have further questions, please do not hesitate to get in contact with us!Melatonin, a Full-Service Anti-Cancer Agent: Inhibition of Initiation, Progression, and MetastasisRussel J. Reiter, Sergio A. Rosales-Corral, Dun-Xian Tan, Dario Acuna-Castroviejo, Lilan Qin, Shun-Fa Yang and Kexin XuInt. J. Mol. Sci.2017, 18(4), 843; doi:10.3390/ijms18040843https://www.mdpi.com/1422-0067/18/4/843Available online: There is highly credible evidence that melatonin mitigates cancer at the initiation, progression, and metastasis phases. In many cases, the molecular mechanisms underpinning these inhibitory actions have been proposed. What is rather perplexing, however, is the large number of processes by which melatonin reportedly restrains cancer development and growth. These diverse actions suggest that what is being observed are merely epiphenomena of an underlying more fundamental action of melatonin that remains to be disclosed. Some of the arresting actions of melatonin on cancer are clearly membrane receptor-mediated, while others are membrane receptor-independent and involve direct intracellular actions of this ubiquitously distributed molecule. While the emphasis of melatonin–cancer research has been on the role of the indoleamine in restraining breast cancer, this is changing quickly, with many cancer types having been shown to be susceptible to inhibition by melatonin. There are several facets of this research which could have immediate applications at the clinical level. Many studies have shown that melatonin’s co-administration improves the sensitivity of cancers to inhibition by conventional drugs. Even more important are the findings that melatonin renders cancers that were previously totally resistant to treatment sensitive to these same therapies. Melatonin also inhibits molecular processes associated with metastasis by limiting the entrance of cancer cells into the vascular system and preventing them from establishing secondary growths at distant sites. This is of particular importance, since cancer metastasis often significantly contributes to the death of cancer patients. Another area that deserves additional consideration is related to the capacity of melatonin to reduce the toxic consequences of anti-cancer drugs while increasing their efficacy. Although this information has been available for more than a decade, it has not been adequately exploited at the clinical level. Even if the only beneficial actions of melatonin in cancer patients are its ability to attenuate acute and long-term drug toxicity, melatonin should be used to improve the physical wellbeing of the patients. The experimental findings, however, suggest that the advantages of using melatonin as a co-treatment with conventional cancer therapies would far exceed the improvements in the wellbeing of the patients. International Journal of Molecular Science and the scientific research field. On behalf of the International Journal of Molecular Science Editorial Board, we would like to congratulate these teams for their excellent work. In recognition of their accomplishment, they will receive the privilege of publishing an additional research article or review paper free of charge in open access format in the International Journal of Molecular Science, after the usual peer-review procedure.We believe that these six exceptional papers are valuable contributions to the International Journal of Molecular Science and thank the International Journal of Molecular Science Editorial Board for voting and helping with this “Best Paper Award”.We would like to take this opportunity to thank all the nominated research groups of the above exceptional papers for their contributions to the International Journal of Molecular Science are committed to meeting the needs of the molecular research community by providing useful and timely reviews of all manuscripts submitted and an open access journal for results’ publication. Please consider submitting your work to the International Journal of Molecular Science. We look forward to announcing your paper as an International Journal of Molecular Science “Best Paper” in the future.The Editorial Board and Editorial Staff at the International Journal of Molecular Science Editorial Board.


The objective of this research was to verify the feasibility of the use of newly synthesized biopolymer materials for sizing cotton yarns based on the basic principles of chemical modification. Research included acid hydrolysis of potato starch up to controlled molar masses together with graft-polymerization and methacrylic acid onto hydrolyzed starch to improve hydrophilicity and solubility, to increase the capability of film forming, to increase adhesive potential and to avoid retrogradation phenomena. Research objectives were primarily focused on finding an appropriate, environmentally-friendly and productive sizing agent for cotton yarns via the analysis and systematization of a large number of synthesis methods in conjunction with the characterization and properties of graft-copolymers. The research results showed that potassium persulfate initiator was most efficient in grafting of methacrylic acid onto hydrolyzed starch, while azobisisobutyronitrile (AIBIN) initiator was most efficient in grafting of acrylic acid (AC). FTIR analysis confirmed that new and efficient products for sizing cotton yarns from synthetized potato starch were obtained. Research on rheological properties of copolymers shows a higher viscosity of grafted products indicating the good stability of potential starches. Ecological improvements have been established through high desizing degree as well as improvements in physical-mechanical properties of yarn, abrasion resistance and decrease in yarn surface hairiness were noticed. The use of new derivatives of potato starch, especially of hydrolyzed starch grafted with methacrylic acid (MAA), potassium persulfate (KPS) as initiator, was confirmed. Anova statistical analysis determined the influence of the entire sizing process on individual yarn parameters. Sizing is a technological process of wet processing of warp yarns to obtain additional properties which are necessary for weaving. The sizing process is nowadays more aimed towards the development and use of natural-based sizing agents. The sizing process is one of the most important and expensive phases in fabric manufacturing; so its contribution in its development and improvement is reflected through the development and automation of sizing machines and the introduction of new, more efficient and more cost effective sizing agents. By using synthetic polymer products, sizing gains significance as a phase in which yarn properties can be greatly optimized, which significantly increases the productivity of the weaving mill and fabric quality. The basic objective of sizing is that the use of the appropriate polymer capable of forming a protective layer on the yarn provides the durability of warp threads and their minimum deformation during short and strong cyclic stresses in the weaving process ,4,5,6,7.Sizing efficacy does not depend only on the adhesion between the applied sizing agent and the yarn, but also on the ability to form a film, on rheological properties of the size, physical-chemical yarn properties, as well as on the technological parameters in the sizing process. Furthermore, it is necessary to completely remove the sizing agent from the fabric after the weaving process in an environmentally friendly manner. Under production conditions it often happens that inadequate sizing agents are used, especially inadequate recipes.The optimization of the proportion and application of sizing agents to the warp threads is of the utmost importance for the entire weaving process in order to achieve the planned machine utilization and the quality of the finished fabric. Optimization of size pick-up is one of the biggest problem in the sizing process even today. The purpose of sizing is to reduce the number of warp thread breakages to a minimum. Observing the curve of the warp threads breakage number  there isThe question is posed whether sizing is unconditionally necessary, because it practically represents an ecological and economic burden in fabric manufacturing. The complexity of the sizing process is reflected in a number of parameters related to the properties of sizing agents, used yarns and sizing and weaving machines which is always a challenge and is a significant field of research.Based on the chemical composition, the sizing agents used nowadays can be divided into the following groups: starches, carboxymethylcellulose, polyvinyl alcohols, polyacrylates and polyester resins. From the group of starches, potato is one of the most commonly used. It disadvantage is that a small drop in temperature suddenly changes the rheological properties of size, and this results in retrogradation, which causes difficult control of the degree of sizing.Starch properties depend on the relationship between amylose and amylopectin, but also on other constituents found in a starch granule, such as phosphates, lipids, phospholipids, etc. However, amylopectin, as the main starch ingredient, exerts a dominant influence on starch properties. The lateral chain length in amylopectin affects clustering, retrogradation and starch properties in the solution. In cold water starch swells, but does not dissolve. Starch granules disintegrate only at elevated temperatures, i.e., dissolving happens whereby amorphous amylose is released first which forms a three-dimensional network outside starch granules and inhibits further swelling of starch granules. Besides amylose, the present lipids also inhibit swelling. Although amylose makes only a slight contribution to the viscosity of the starch solution after granule disintegration, when cooling the viscosity of the starch solution increases with increasing amylose content, which is explained with amylose crystallization and gel structure formation. It is known that, if starch solution is allowed to stand, starch retrogradation occurs, which is one of bad indicators for commercial use as a sizing agent. An increase in the concentration and a decrease in the solution temperature accelerate retrogradation, while very short chains (degree of polymerization 6–9) suppress starch retrogradation ,14,15,16In order to allow recycling using ultra-filtration, sizing agents must have the following characteristics: water solubility, mechanical and thermal stability, biological resistance, good washing performance, low average viscosity ,18,19.Starch is mostly commercially applied in sizing cotton warp yarns, although with considerable shortcomings: (a) molecule size which limits the penetration into the yarn, (b) instability of size viscosity due to temperature changes during cooking until preparation and sizing process, (c) film rigidity , (d) sensitivity to microorganisms . Modification of natural starches is done just to eliminate the above mentioned shortcomings and to increase their usability for industrial applications ,21,22,23Hydrolysis of potato starch and vinyl monomers—acrylic (AA) and methacrylic acid (MAA) by using various initiators (azobisizobutyronitrile (AIBN), potassium persulfate (KPS) and benzoyl peroxide (BPO) was performed. The use of AA monomer in the process of grafting natural starch was found in textile finishing, but not in yarn sizing. Also, the absence of research of starch MAA grafting for use in sizing was crucial for their choice, assuming the behavior in the practice of the modified size film on the yarn, taking into consideration the presence of polar and non-polar parts in the structure of sizing agents. Hydrolysis of starch was carried out in order to reduce molar mass, which implies easier solubility without bulky agglomerates in the size, easier penetration into the yarn structure and later easier removal from the fabric. Monomers were grafted onto shorter starch macromolecules, creating lateral shorter or longer branches on the main chain, thus forming a product for a more efficient use in yarn processing. A variation of the initiator was performed in order to form grafted monomers more efficiently on the starch and because of the differences of bonded ones on longer or shorter lateral chains and/or denser packing of lateral chains. Later, that can greatly affect size rheology and the behavior of the film on the impregnated yarn ,25.The optimization of the technological sizing process conditions refers to the definition of the particular parameters of the laboratory sizing machine: thread tension between the bobbin creel and the size box; temperature of the sizing agent in the size box; sizing speed—passage of the threads through the size box; pressure of the immersion and squeezing rollers; temperature of the cylinders of the contact dryer, size circulation and exit moisture.Cotton yarns of different structures (single and double) were sized using different size recipes in order to find the optimal ones, which would, in practical terms, achieve the most efficient results on the weaving machine. During the research the best conditions of grafting, temperature-time regime, type of initiator and monomer were defined ,27,28. FFor the purposes of this research 100% ring spun single cotton yarns with counts of 20 tex and 30 tex (700 twists/m) and ply yarns with counts of 20 × 2 tex and 30 × 2 tex (324 twists/m) were used. Egyptian cotton fibers with lengths 27–28 mm and average diameter of 4.5 μm were spun into a yarn. The yarn was spun and plied by the Textile Company Bimtex, Leskovac, Serbia.2H5OH  and sodium carbonate—Na2CO3 .For the purpose of this research the following active products were used: potato starch , hydrochloric acid—HCl , ethyl alcohol (ethanol)—C2S2O8  and benzoyl peroxide (BPO) (C6H5CO)2O2 . As monomers in the grafting process were used: acrylic acid (AA) C3H4O2  and methacrylic acid (MAA) C4H6O2 .The following initiators in the grafting process were used: azobisisobutyronitrile (AIBN), i.e., ) 99% , potassium persulfate (KPS) KThe structures obtained by copolymerization are very complex, which is confirmed in many works with polysaccharides. Most commonly, graft polymerization is brought about by free radical addition polymerization. Even though a large number of works on graft copolymerization has been published, there is not a comprehensive understanding of the grafting process yet. The grafting schemes in The yarn sizing process was carried out on an innovative laboratory sizing machine adapted to industrial conditions  for the single yarn were: 5%, 10% and 15%, and for the ply yarn: 1%, 3% and 5%, adapted to industrial conditions. In the weaving process warp threads are strained and subjected to dynamic stresses, resulting in their deformation and breakage. It is not necessary to size the ply yarn with the amount of starch as a single yarn because ply yarns mostly have satisfactory tenacity properties. In that case, it is only sufficient to connect the fibers on the yarn surface, which is conducted by using lower concentrates of starch. The size was prepared by mixing sizing agents in cold distilled water. After grinding, the bath was gradually heated with intense mixing up to 80 °C during 30 min and then 5 min at a temperature of 95 °C. Afterwards the size paste is ready for sizing, and the following conditions are adapted before sizing:n, Mw, Mz, D) was conducted by gel permeable chromatograph GPC Agilent 1100 Series, Agilent Technologies, Santa Clara, CA, USA, using a differential refractometer (RID detector) of 1200 Series, Agilent Technologies, USA, as a detector. Mn represents the number average molecular weight calculated from the number of macromolecules of the polymer, while Mw represents weight average molecular weight calculated on the basis mass of these macromolecules. Mz is z-average molecular weight that also depends on the size and weight of molecules. For polymers characterization it is essential to determine the polydispersity index D and to define the degree of polymer inequalities. Dispersion is a measure of molecular weight distribution or the degree of polymerization, which is for uniform polymer D = 1.Determination of average values of molecular weights and the distribution of copolymer molar weights , according to standard ISO 2062.Unevenness testing carried out on a Keisokki Evenness Tester Model 80, type B  according to ISO 16549. The criteria selected for yarn testing are: recording thick places of the yarn over 50% of the average thickness, recording thin places of the yarn under 50% of the average yarn thickness and recording yarn slubs  of the yarn over 200% of the average yarn thickness.Yarn hairiness tested on a Zweigle G 565  instrument for yarn hairiness testing according to standard ASTM D 5674-01.Yarn twist was determined using a MesdanLab Twist Tester  according standard ISO 17202.Abrasion resistance of the yarn was measured on a Zweigle G551 yarn abrasion tester Desizing was conducted using ultrasound and washing off process. Ultrasound desizing process was performed in a Ultrasonic Laboratory Reactor URS 1000 , with the frequency of applied ultrasound oscillations of 40 kHz, using 150 W, at 60 °C for 30 min. Washing off process was performed using washing machine Ahiba Linitest , by washing agent Lavan NH, Textilcolor AG, Sevelen, Switzerland (2 g/L concentration), at 60 °C for 30 min, followed by abundant water wash and air drying.−1 was conducted.The FTIR analysis of samples—potassium bromide technique, spectrophotometer BOMEM Hartmann & Braun MB-Series  in the range of wavelengths 4000–400 cmHPLC (high pressure liquid chromatography) method was used to investigate the residual amounts of the unreacted monomer in the copolymer. Tests were carried out on the device Agilent Series 1100 HPLC with a diode-array detector, DAD 1200 Series . The detection wave length is 205 nm. The ZORBAX Eclipse XDB-C18 column, 4.6 × 250 mm, 5 μm was used. The effluent is methanol, the flow rate is 1 mL/min, the column is thermostated at 25 °C, the injected volume is 20 μL. Monomer standards were prepared by single weighing of the sample with diluted methanol.Scanning Electron Microscopy (SEM) was performed on a JEOL JSM–6610 LV microscope .m1—yarn mass after sizing (g); m0—yarn mass before sizing (g);Size pick-up (D) on the yarn was determined using the mass technique according to the equation:Apparent viscosity on the rotational viscometer “Visco Basic Plus” . The spindle speed of the viscometer is 60°/min, time: 15 min to 40 °C, 20 min to 60 °C and 30 min to 85 °C.Vs) according to the equation [V—apparent viscosity of size, maxV and minV—maximum and minimum of the measured viscosity over a period of 7 h.Viscosity stability (equation :(2)Vs= Anova: Analysis of Multiple Linear Regression (Multiple Regression), linear linkage of key variables and their predictors, Levene test, Scheffe test, To conduct an overall analysis, tests on unprocessed and processed samples were carried out according to standardized methods:For the purposes of this research potato starch was used for hydrolysis and afterwards for grafting of various monomers. Starch hydrolysis was carried out to reduce molar weight, to increase the solubility and availability of active centers for chemical modification.w (weight average molecular weight) was higher than Mn (number average molecular weight), which confirms polydisperse systems, respecting the rule that the greater difference between the Mw and Mn is, the systems is more polydispersonal. It is known that all the synthetic polymers are polydispersed and the valid order for them is: Mz > Mw > Mn [ Mw > Mn . Less waGraft copolymerization was carried out whereby monomers were grafted onto shorter starch macromolecules, forming lateral branches on the main chain resulting in a product, which can be more efficiently used as a sizing agent. By increasing the index of polydispersity, the presence of chain contents with lower molar weight values is greater, whose mobility is also greater (for example sample HS-AA-KPS). Shorter chains are easily movable in the solution and serves as a “lubricator” (plasticizers) during movement of a longer chain or their aggregates . A varia–yield of starch hydrolysis (Ysh):–graft yield (Yg):–grafting percentage (Pg):–percentage of graft efficacy (Pge):–W1—mass of hydrolysed starch, W0—mass of natural screed, W2—mass of grafted starch (gravimetric method), W3—mass of used monomer, W4—mass of residual monomer.conversion of monomer to polymer (Cmp):Characterization of all grafted monomers onto hydrolyzed starch was performed based on the following equation:−1 is observed, which stems from O–H valence vibrations as well as a smaller peak at 2925 cm−1 which is attributed to the C–H valence vibration. Wave numbers at about 1153, 1078 and 1023 cm−1 describe C–O–C stretching (triplet of starch) and the maximum band at about 1638 cm−1 originates from water molecules [olecules ,42.−1 (C=O stretching). If it is a carboxylate anion, there are two ν (C=O) maximums, one of which is at about 1637 cm−1 νas (C=O) and the other at about 1420 cm−1 νs (C=O). Bands at about 1458 and 1375 cm−1 indicate deformation vibrations of the methyl group, δas (CH3) and δs (CH3), respectively [Potato starch grafted with AA—in the spectrum characteristic bands appear which originate from polyacrylic acid. The carboxylic acid group is detected through the absorption of the carbonyl C=O group at about 1733 cmectively ,44,45.−1 originates from valence vibrations C=O. Also, bands coming from valence of the O–H group at about 3410 cm−1 are formed, valence vibrations of CH2 group at about 2927 cm−1 and deformation vibrations of CH3 in the plane having a maximum at 1374 cm−1 [The confirmation of grafting of MA onto the hydrolyzed potato starch can be found in new bands in the FTIR spectrum. The absorption with a maximum at about 1716 cm374 cm−1 .Chromatography is a high-performance liquid method (HPLC) used to separate liquid mixtures. According to the obtained HPLC results of hydrolyzed starch, it is possible to determine the difference between graft products and initiators. The viscosity of the sizing liquor, which is also defined as its flow, mostly depends on the time of left standing unused, on circulation and temperature. During the preparation of the solution it is noted that at lower concentrations of up to 3%, the solution of hydrolyzed potato starch behaves almost like a Newtonian fluid, i.e., starch macromolecules are sufficiently distant so that no strong physical crosslinking occurs. Potentially formed bonds are easily broken under the action of mechanical forces and during testing they fail to form again. By analyzing the relationship between hydrophilic and hydrophobic interactions and the effects of secondary chemical bonds, it is noticed that the grafted macromolecule exhibits a specific behavior in the solution, which is reflected in viscosity and then in binding to the cotton yarn in the sizing process.The viscosity stability of the solution of potential sizes was tested by heating to 85 °C for 7 h together with viscosity measurement every hour . Table 5The grafted products have a higher viscosity than a non-grafted hydrolyzed product, which is indicative of the good stability of potential sizes. By increasing the viscosity the surface size pick-up is higher, while in the case of low viscosity the size pick-up is lower on the yarn surface, but more uniform and higher in the yarn interior, which is an additional essential requirement for the sizing process. Higher size temperature allows a faster movement of size molecules, and hence a higher degree of overcoming adhesion forces and better adsorption of the size to the fibers in the yarn interior.Yarn sizing was performed according to the designations in The test results of some mechanical properties, Yarns sized with starch with MAA monomer achieves slightly better results of breaking force than yarns sized with starch with AA monomer. This indicates to more uniform distribution and appropriate adhesion of this starch type (with MAA monomer), both on the yarn surface and in the yarn interior. The consequence of sizing is a reduction in elongation at break of all yarns, probably because the yarn became encapsulated and trapped by the size coating, making it less elastic.This reduction in breaking elongation of yarn is a shortcoming of sizing, whereby it is extremely significant that result variations are as low as possible which is manifested in this study. It is interesting to mention that breaking elongation of yarn sized with sizing agents with MAA and AA monomers hasn’t decreased a lot, which is convenient for practical use.Yarn abrasion resistance is one of the basic properties in weaving whereby the number of yarn breaks during weaving or weaving machine efficiency can be predicted, By applying the size to the yarn all tested samples of the sized yarn increased abrasion resistance or the number of abrasion cycles up to breakage.Ply yarns (20 × 2 tex and 30 × 2 tex) has greater abrasion resistance before and after sizing process. The tendency to increase the abrasion resistance has a single yarns (20 tex and 30 tex) indicating the justification of conducting sizing process for this yarn. Yarns sized with hydrolyzed starch HS-MAA has a higher abrasion resistance increase compared to yarn sized with hydrolysed starch HS-AA starch.Grafted starch proved to be an efficient product with regard to abrasion resistance. The reasons for such results of polymer chains in the starch macromolecular structure can be sought in its hydrophobicity. This fact can be the reason why the size softens or plasticizes, why fibers do not stick together or why some kind of yarn lubrication is achieved .Hairiness can be defined as the state of migrated fiber ends and fiber loops pushed to the surface of the yarn body, not adhering to it. Some fibers have one of their ends fixed inside the yarn while others protrude under the influence of mechanical and geometrical causes. The intensity of yarn hairiness depends on the spinning method, degree of fiber parallelization, fiber types and lengths, yarn twist and other causes. One of the goals of sizing is to reduce yarn hairiness which negatively affects yarn abrasion in contact with the elements of the weaving machine. Yarn hairiness test results are shown in The largest part of the protruding fibers are 2 mm long up to the yarn body. After sizing, the yarn hairiness (according to the measuring ranges) decreases, which is also one of the basic objectives of the sizing process. From the obtained results it is evident that sizing masses with higher concentrations have a better effect, i.e., the number of protruding fibers according to measuring ranges drastically decreases, even more in single then in ply yarns. Greater lengths of the protruding fibers cause thread entanglements and more yarn breakages in weaving. By observing the obtained results it is evident that the best effects of sizing in terms of hairiness reduction were achieved by using the HS-MAA-15/HS-MAA-5, for even more then 50% in single yarn and around 30% in plied yarn 30 × 2 tex, while this maximum reduction in yarn of finesses 20 × 2 tex is just 10%. The weakest effect on hairiness reduction was achieved with HS-5/HS-1 for all tested samples.Desizing was performed in two ways: by using ultrasound and washing off . HydrolyThe use of ultrasound in washing, as an additional source of highly usable energy, brings significant improvements, i.e., the removal of the size material from the warp yarn is more intensive. The best values of removing the size material from the single yarn by using ultrasound amount to 97% for starch HS-MAA-1 and in the case of the ply yarn the degree of desizing amounts also to 97% when using the same starch HS-MAA-1.Sizing agents are major polluters of wastewaters in the textile industry due to great amounts of acids, oxidants, enzymes, bacteria etc. The results of the analysis of waste water after desizing are shown in The analysis of individual research results from the point of view of statistical modelling and event prediction is of great importance in the analyses of individual yarn parameters that are affected by the sizing process.This analysis deals with the parameter yarn breaking force as one of the most significant yarn parameters. It is one of the main reasons for sizing in order to improve yarn strength. The subject of research was interrelationship between breaking force (dependent variable) and the following parameters: degree of size pick-up, yarn hairiness, yarn count and yarn twist – independent variables. According to the basic yarn data and test results  the equaIf one example of predicting the value of variable Yarn strength is taken for 20 tex yarn sized with AA copolymer and hydrolyzed potato starch (HS-AA-5), it is:Consequently, yarn strength  = 383.96 cN.Actual measured value of this variable is: Yarn strength  = 380.00 cN.−12, 0.01828, 3.93 × 10−13 or 0.0022 < 0.05).With a probability of 95% it is claimed that a single sized yarn has the value of variable Yarn strength of 383.96 cN. Practically, each value of the variable Yarn strength can be described with this model (coefficient of determination = 0.991). All variables contribute to the model, which is verified statistically , Hydrolyzed and grafted starches showed different properties, depending on the type of initiator used, but also on monomers. Based on the research methods used, mathematical and statistical analyses, it can be concluded:Grafting with vinyl monomers depends on the used initiators. KPS initiator was the most efficient in grafting methacrylic acid onto hydrolyzed starch while AIBN initiator was very efficient in grafting of acrylic acid. The most important measurements in the synthesis of copolymers, yield of hydrolysis and grafting, grafting percentage and efficiency, conversion of monomer into polymer, as well as FTIR analysis confirmed that these are new starch and vinyl monomer products. All grafted products increase viscosity in comparison to non-grafted hydrolyzed starch, which is indicative of the good stability of a potential product. It is evident that the changes in temperature of the copolymer solution affects the viscosity. By increasing the concentration of starch, the size pick-up ratio also increases, and this is somewhat higher for polymers than for hydrolyzed starch, while the HS-AA copolymer is particularly emphasized. Ply yarns adsorb or bind to themselves more sizing agents in all cases in comparison to single yarns, which is related to higher volume, looser structure (yarn porosity) and smaller number of twists. Products with MAA copolymer achieve the best results with regard to breaking force for all types of yarn, which indicates their more uniform distribution within the yarn and good adhesion both over the surface and in the interior of yarn. A consequence of sizing is a reduction in the elongation at break of yarn, while products with MAA copolymer retain the elongation values which are approximate to the values of the unprocessed sample. By applying the size to the yarn, all tested samples of the sized yarn increased abrasion resistance or the number of abrasion cycles up to breakage. Grafted starch showed good resistance to abrasion. The best effects of sizing in terms of hairiness reduction were achieved with HS-MAA-15/HS-MAA-5, while the weakest effect was achieved with HS-5/HS-1, for all tested samples. In the desizing process by washing, as the most effective starches proved to be HS-AA-5, HS-MAA-5 and FOR HS-MAA-10 for single yarns and HA-MAA-1 for ply yarns. In the case of the desizing process using ultrasound, the starch HS-MAA-1 proved to be the easiest to remove from both single and ply yarns. The greatest advantage of polymers from an ecological point of view is manifested as biodegradability. The analysis results of the wastewater after desizing of the samples are promising for all tested parameters, where the obtained values of the ratio between biological and chemical oxygen demand belong to the range of values that indicate partial biodegradability. It is an advantage that the grafted starches do not disintegrate in sizing, but dissolve in water which allows recycling.By analysis of the sized yarn it can be ascertained that synthesized starches yielded good results with regard to improving breaking force, abrasion resistance and reducing yarn hairiness. Statistical analyses of individual parameters and determining the finite models revealed their interrelationship, and thus the complexity of research. Careful selection of the synthesis process of the active agent, valid combination of modified sizing agents as well as the optimal choice of temperature-time regime make it possible to obtain an appropriate size paste composition and processing method which will enable uniform yarn sizing.Based on the extensive analyses carried out, it can be concluded that economic, qualitative and environmental cost-effectiveness supports the reuse of natural starches in the sizing process, but only by synthesizing and grafting with appropriate initiators that significantly improve their properties. Further research will focus on the gradual reuse of natural synthesized starches, first as a mixture with synthetic starches, and then until their complete replacement.


The ability of natural systems to change functions in response to altered environmental conditions has inspired scientists during the last decades to fabricate smart materials that respond to different stimuli . These responses are typically manifested as remarkable changes from the molecular to the macroscopic level. Among many kinds of stimuli-responsive materials, gels have been recognized as versatile functional materials for numerous exciting applications, in areas such as personal care, medicine, food, agriculture, bioengineering, art restoration, and electronic devices. Despite different forms of gels that are already well-integrated in everyday life, the development of new gels and their applications is growing at extraordinary pace, stimulating even the naissance of new paradigms that challenge established knowledge. Consider, for example, the concept of gel-like nature of the cytoplasm described by Gerald H. Pollack, which has confronted the wisdom on how cells work, and turned into a persuasive new foundation for cell biology.When I first introduce gels to my undergraduate and graduate students, including practical examples, they feel immediately interested and fascinated by how they are formed, their dynamic nature (in contrast to the popular perception) and their widespread presence in our lives (including in our own body!). In fact, for many years I have found myself completely captivated by gels and their amazing properties! Gel materials are expected to form part of prominent solutions to major problems, such as limited resources, and safeguarding human health and the environment.A quick look at the constantly increasing literature dealing with gels demonstrates that more and more researchers worldwide are becoming engaged in this fascinating topic. Thus, we have envisioned the convenience of a new journal devoted to these materials that could serve as a reference, by bridging the gap and promoting fruitful interactions between very different fields that, in one way or another, are beneficiaries of the properties of gel materials. For this journal, a broad range of gels will be considered. Articles covering in detail preparation methods, characterization, functionalities, mechanistic studies, and applications of either chemical or physical gels made from low molecular weight compounds or polymers—including, for example, organogels, hydrogels, aqueous gels, ionic gels, organic-inorganic hybrid gels—are within the scope of the journal. Theoretical studies with explicit solvent molecules, and studies focused on the relationship between solvent properties and gelation ability are also becoming increasingly important in the field, as they may contribute to a better understanding of gelation mechanisms. Hence, contributions of this nature will be also highly appreciated.Gels is committed to rapid dissemination of knowledge through an exemplar model for high quality publications under the open access format. While other publishers require access fees that are continuously increasing and, in many cases, very high costs for covering color images, MDPI charges only moderate article processing fees without institutional subscriptions. In this way, the journal aims to sustain a quick, yet rigorous peer-review process and rapid publication once a contribution has been accepted, which will be freely available to everyone in the world. Nevertheless, contributions published in the first two years of Gels will be exempt from article processing fees. This publishing model is also expected to encourage the research of countries that have not historically been very active in the field.The publisher of During the launch of the journal we will publish a series of special issues, based on areas of expansion and the latest advances in the field. One of the main aims of these issues is to provide a forum for researchers from different disciplines to learn and identify the major challenges in the field of gels. The broad scope of the journal, in terms of different kinds of gels, is expected to stimulate new discoveries by successful implementation of breakthrough concepts from one field in another. Within this context, we envision the first series of topical issues covering gels with self-healing properties; applications of gels in biomedicine, catalysis, sensors, environmental remediation, and energy; gelation of fluids at room temperature; gels as selective micro- or nanoreactors; elucidation of gelation mechanisms; and computational modeling of gel systems. Proposals for other topics that you think should be explored in a special issue are most welcome, as are appropriate guest editors.Gels, as well as your comments and ideas that can contribute to make this journal a prominent and unique platform for scientific discussion and rapid dissemination of knowledge in the fast-growing and interdisciplinary field of Functional Gels.On behalf of our Editorial Board, I cordially invite you to submit your articles to Editor-in-Chief of GelsDavid Díaz Díaz


The aim of this study was to evaluate the shear bond strength of orthodontic tubes adhered to ceramics with the Transbond™ XT bonding resin  while varying the surface treatment. Then, the adhesive remaining index (ARI) was verified, and the representative fracture patterns were evaluated via scanning electron microscopy. Forty-eight zirconia blocks were divided into three groups, varying the number of layers of the 10-methacryloyloxy-decyl dihydrogen phosphate (MDP) primer: one, two, or three applications. In addition, 16 lithium disilicate IPS E.max ceramic disks  were conditioned with 10% hydrofluoric acid for 20 s and underwent a single-layer primer application regimen. The four groups were further stratified to undergo bond testing after either 24 h (control) or 5000 cycles in a thermocycling machine. A shear bond strength test was performed (0.5 mm/min), and the MPa values obtained were submitted to a two-way analysis of variance and Tukey’s test. There was no statistical difference among the control group ceramics that received the varying surface treatments. After thermocycling, it was verified that both the E.max disks and the zirconia ceramics with three primer applications obtained the highest bond strength values. In the 24 h groups, a total displacement of the resin from the orthodontic tubes was observed (ARI of 1). After thermocycling, the highest prevalence of an ARI of 5 (adhesive failure) was observed among the zirconia ceramics with single-coat primer application, followed by those with triple-coat primer application (mixed failure). Three applications of the MDP-containing ceramic primer achieved the best result in the present study. Zirconia surface should be treated with three coats of MDP primer to achieve a level of bond strength similar to silica-rich phase ceramic. Zirconia is widely used as a ceramic crown material in dentistry. It has superior aesthetic appearance in comparison with metallic restorations and high mechanical strength in relation to other ceramic materials ,2. NowadDespite providing structural strength, this ceramic’s high crystalline phase makes it harmless to hydrofluoric acid ,5,6,7. SNotably, the use of primers or resin cements containing 10-methacryloyloxy-decyl dihydrogen phosphate (MDP) may increase zirconia bond strength between zirconia ceramics and resin materials ,17,18,19Even with this idea consolidated in the literature, there is not yet any definitive protocol for the stable chemical treatment of zirconia, as in the case of ceramics containing silica, which may be treated with hydrofluoric acid and silane , or in cThe materials are described in 2, with application lasting 10 s on each side . This ceramic was used, because it has SiO2 in its composition, which is affected by the presence of 3-MPS in the composition of the ceramic primer.The 16 IPS E.max specimens, previously polished with a Sof-Lex™ disk , pumice stone, and water, were conditioned with 10% hydrofluoric acid for 20 s and washed thoroughly with air–water jets. A layer of ceramic primer air-drying was applied, and tubes were subsequently bonded with Transbond™ XT resin . Any excessive resinous material was removed with the aid of an exploratory probe, and the assembly was photopolymerized  with a light intensity of 1000 mW/cmSeparately, the 48 zirconia specimens were randomly divided into three groups of 16 each. In the first group, the second molar tubes were bonded as recommended by the primer manufacturer . The zirconia received a layer of the primer and was dried with an air jet. The tubes were then bonded using the same Transbond™ XT resin, the excess was removed with the aid of an exploratory probe, and the specimens were photopolymerized in the same manner as previously described. In the second group of 16 zirconia specimens, the second molar tubes were bonded after the same preparation process outlined in the first group, but two layers of primer were applied before bonding and dried with air jets between the applications and immediately prior to bonding. Thereafter, the tube was bonded in the same manner as described above. Finally, in the third group of zirconia specimens, the tubes were bonded in the same way as in the previous two zirconia groups but with three layers of primer applied and dried with air jets between the applications and immediately before bonding. Again, the tubes were bonded in the same manner as described above.Next, each of the four 16-specimen groups were randomly divided into two groups of eight specimens each. The groups underwent either a bond strength test 24 h after the bonding (control) or after 5000 cycles in a thermocycling machine (5 °C and 55 °C for 30 s each) following the bonding, as presented in 2), leading the results to all be expressed as sheer bond strength in megapascal (MPa) values. The groups described in The specimens were then evaluated using a shear test device . The device was attached to the bottom of a universal testing machine . A chisel-shaped beveled stainless-steel tip was attached to the 5 kilonewtons (kN) load to test the shear bond strength between the ceramic and the base of the orthodontic tube. A crosshead speed of 0.5 mm/min was used to test the shear bond strength, thereby developing a degree of shear stress at the tube–resin base interface until the moment of detachment failure. The values were recorded directly in N on the digital monitor of the testing machine. Subsequently, the value in N of each specimen was divided by the internal area of the bracket , and the amount of resin remaining was classified according to a “Resin Index”  14]. A . A 14]. p < 0.05). The Tukey’s test results  and those who had thermocycling aging  compared the effects of different surface treatments on ceramics . The ideThe ceramic primer used was a blend of ethanol solution (nearly 80% by weight), MDP, and a quantity of less than 5% by weight of silane. This material was initially designed to treat different types of ceramics, including those rich in silica, alumina-reinforced, or composed almost entirely of zirconia ,24,25. TAfter thermocycling, the E.max ceramic had its strength value lowered by only 4.3%, while the zirconia triple-coat group showed a reduction in bond strength of 18.5%, the zirconia double-coat group experienced a reduction of 33.8%, and the zirconia single-coat group presented a reduction of 71%. Of note, the thermocycled E.max and zirconia double-and triple-coat specimens had bond strengths that remained sufficiently efficient enough to comply with the value established by Reynolds in 1975 , althougThe MDP is capable of establishing a very intensive and stable chemical interaction with hydroxyapatite . AdditioIt should be noted that, at each primer application in the present study, a solvent evaporation procedure with a continuous air-jet application of 10 s was performed. This airflow allowed for the evaporation of any residual ethanol, which, according to the manufacturer, is present in up to 80% by weight in the solution. In dentin, the excess solvent leads to the formation of a hybrid layer, and the adhesive layer becomes more hydrophilic and susceptible to water absorption over time. This leads to the softening of the polymers and, consequently, the breaking of the long polymer in smaller chains, which make the resin materials more prone to crack propagation .Thermocycling in water baths has been used to simulate the aging effect on resin materials ,30. The Further studies are needed to evaluate different surface treatment methods. A limitation of the present study was to use only one zirconia ceramic and only one type of ceramic primer. Future studies may take advantage of other varieties of products or even treat ceramics with different universal adhesives. Additionally, different aging methods can be used to challenge the bond between ceramics and resinous materials, such as long-term storage in water at 37 °C, thermocycling greater than 5000 cycles, and use of mechanical cycling.Within the limitations of this study, it is possible to conclude that thermocycling decreased the shear bond strength of all test groups, including one containing a silica-rich ceramic. It is recommended that ceramics composed essentially of zirconia must be treated with at least three coats of MDP primer so as to exhibit a bond strength comparable to that of a silica-rich ceramic treated with hydrofluoric acid and silane. This implies a more conservative procedure and an alternative to mechanical treatments that may harm the labial surface of the ceramics.


The SEM images showed significant and nonuniform impact of ultrasound on the structure of starch granules in which some granules remained almost smooth, but some showed high irregular surfaces or even in some cases structure collapse. The highest disintegration of granules was obtained in probe 200 W treatments.Ultrasound has been rapidly applied successfully in diverse food technological aspects including improvement of functional properties of food ingredients such as starch. This work was carried out to compare the influence of two types of sonication, bath and probe, on several physicochemical and microstructural properties of wheat starch. Two sonication probes (200 and 400 W) and a sonication bath (690 W) were applied to treat wheat starch suspensions at 15 and 30 min. Sonication time in 400 W probe was intermittent while for the other treatments, it was continuous. Swelling capacity (SC), solubility (SB), turbidity (TB), and oil absorption (OA) parameters were investigated for native (control) and sonicated wheat starch. Moreover, scanning electron microscopy (SEM) was performed to determine the influence of sonication treatments on the morphology of wheat starch granules. The highest level of SB and OA, as well as the lowest SC, was obtained for starch samples treated with 200 W sonication probe, while no significant difference ( The amylose (amorphous region) and amylopectin  chains are the composing units of semicrystalline structure of starch  and continuous sonication compared with intermittent sonication has rarely been studied. Therefore, this work was aiming to examine the influence of different sonication devices (probe and bath) with different powers and different treatment times (continuous vs. cycle set) on PH‐CH and microstructure properties of wheat starch.22.1Powdered wheat starch  was used in all experiments. The suspensions were produced by suspending 10 g wheat starch in 90 ml distilled water to provide 10% (W/W) samples. Then, the suspensions were mixed on a magnetic stirrer (IKA RCTBASIC) at speed 1,500 rpm for 15 min and utilized in the following steps.2.2For sonication treatment of wheat starch suspensions, firstly, two types of ultrasound probe devices with 24 kHz frequency (UP 200S and UP 400S) were applied. 500 ml volume of prepared samples was placed in a conical flask. Ultrasound probe equipped with a vibrating titanium tip (diameter: 8 mm) was immersed into the suspension container and each sample was sonicated continuously (200 W) or intermittently (400 W) for 15 and 30 min, while the amplitude was set at 100%. In other words, for the two 400 W samples, the intermittent condition, instead of continuous sonication was applied. For this, after every 5 min of treatment, one minute resting time was considered. For bath sonication, 500 ml of starch samples were poured directly into the ultrasound bath  and treated with ultrasound waves (40 kHz frequency and 690 W power) for 15 and 30 min. Different treatments and their relevant conditions have been depicted in Table 2.32 × 12 cm) were placed on the trays of the freeze dryer (−55°C) for 6 hr (<100 Pa) to freeze and dry the starch samples.Upon the end of ultrasound treatment, the starch samples were dried by using a laboratory scale freeze dryer (Christ‐Alpha 1–2 kg –LD). The dishes containing the starch suspensions (0.12 m2.42.4.1W0) inside a tube and 10 ml distilled water was added. Then, the tubes were heated in a water bath  at 85°C for 25 min. The tubes were cooled to room temperature and centrifuged (Heraus Christ‐Multifuge x1) at 2,200 rpm for 20 min. The supernatant samples were dried to constant weight (W1) using a vacuum oven (Fischer Scientific) at 110°C for 5 hr. The wet starch sediments were also weighed (W2) to measure the SC of starch samples. The experiments were done in triplicates. The SB and SC were determined using the following equations  and solubility (SB) of the starch samples were analyzed according to the method described by Chang, Lin, and Chang . Firstly2.4.2A, the absorbance at 650 nm; I, the path length of cuvette (m).The turbidity (TB) of sonicated starch samples was measured according to the method suggested by Jambrak et al. . Firstly2.4.3For this index, 10 ml rapeseed oil was added to the tubes containing weighted starch powder samples (1 g) and the tubes were homogenized at 1,000 rpm for 1.5 min (Heraus Christ‐Multifuge). After 5 min, the samples again were homogenized at 1,700 rpm for 12 min. Then, the unabsorbed oil was rinsed and the weight of absorbed oil was determined , under accelerating potential of 30 kV.2.6α = 0.05 significant level.All treatments were triplicated, and values were representative of the mean of three measurements. The impact of different sonication treatments on starch properties was investigated with the ANOVA , using SPSS version 21 (IBM). The significant differences among means was determined by Duncan's test, performed at 33.1The SC and SB are two key factors which provide information on the quantity of interactions between starch chains associated with the amorphous and crystalline regions. The degree of this interaction is affected by the numerous parameters such as the ratio of amylose/amylopectin and the branching level and length of the amylose and amylopectin  the SC for all samples, compared with the control sample (with a SC of 12.63%), except for the sonication probe 400 W for 15 min, which the decrease in its SC was not statistically significant (p < 0.05). The highest reduction in the SC was obtained for the sonication probe 200 W samples , followed by the sonication bath treatment for 30 min (8.25%). The lower effect of ultrasound treatment at higher intensity (400 W), compared with the lower intensity (200 W) on the SC could be due to the intermittent conditions used in 400 W probe sonication, compared with the continuous application of probe sonication for the 200 W samples. The continuous sonication resulted in a higher temperature, rather than the intermittent use, even in higher intensities (400 W).The SC of untreated and sonicated wheat starches are shown in Figure The decrease in the SC of sonicated starches might be due to the structural fragmentation of starch granules during the ultrasound process (as observed in SEM images) and loosening of starch polymer network  raised the SB of wheat starch samples, compared with the control sample (7.53%), except for the ultrasound bath for 30 min, which its influence was not statistically significant (8.94%). The two highest SB values were obtained for the ultrasound probe 200 W samples . Similar to the SC results, the lower effect of ultrasound at higher intensities (400 W) compared with the lower intensities (200 W) might was due to the intermittently use of probe sonication at 400 W and a The major changes on the starch granules caused by ultrasound are through the cavitation forces, which break down the crystalline molecular structure and the chains of starch by disrupting bonds  are important parameters affecting the starch paste TB. Researchers reported that separation of several heterogeneous materials  during starch modification through physical technologies might be the main cause of alterations in color and clarity levels of starches which are closely associated with the TB  effect of ultrasound on the wheat starch TB, as shown in Figure p < 0.05) higher TB than the native starch, except for the treatment of ultrasound probe 200 W for 15 min, which its TB was similar to the native starch (1.00%). The sample sonicated with probe 400 W for 30 min presented the highest TB (1.25%). Similarly, Sujka and Jamroz  increased the OA for the wheat starch samples sonicated with the probe 200 W for 15 min and 30 min , and the ultrasound bath for 30 min (3.22%), compared with the control sample (1.74%), as presented in the Figure p < 0.05) difference with the control sample. In a study by Sujka and Jamroz (The oil absorption (OA) is a physical entrapment which is dependent on the size as well as the shape of starch granules (Verma et al., d Jamroz , the ultd Jamroz . Huang ed Jamroz  showed td Jamroz .4Ultrasound, compared with the traditional technologies used for starch modification, is much more energy efficient which increases the temperature of treatment medium in a lower extent. Our results showed an increase in the SB as well as the OA degree of sonicated wheat starch samples. The disruption of the granular structure resulted in a higher water and oil uptake might was the key cause of increased SB and OA levels due to sonication. The decrease in the SC for sonicated samples might was due to the increase in temperature and collapse of granules and led granules to lose their ability to swell. The SEM images showed the great mechanical damages imposed on starch granules in some of ultrasound treatments. This study by presenting thorough information on the changes in the structure and PH‐CH characteristics of wheat starch subjected to the different ultrasound treatment can be used as a base for further works. As the PH‐CH features of wheat starch profoundly varied due to the changes in ultrasound treatment conditions, more study needs to be carried out to optimize the process parameters and propose the best ultrasound conditions according to the initial starch properties. Ultrasound conditions, such as power and frequency, time, and temperature, are among important factors that should be optimized to inhibit or decrease adverse impacts of sonication.All authors declare that there is no conflict of interest.There was no human or animal testing in this study.


David Shalloway   . Ono andIP2 .A theme in Freed’s research for many years has been the interplay between the gp41 cytoplasmic tail and the MA domain of Gag. His early work had shown that single amino acid mutations in MA block Env incorporation, and that this block can be overcome by deleting the gp41 cytoplasmic tail . Freed’sAn additional focus of Freed’s research since the early 2000s has been the development of HIV-1 maturation inhibitors –45. In cResearch in the Freed laboratory has benefited greatly from a number of productive and rewarding collaborations with investigators both within and outside of the NIH, including Schuyler van Engelenburg, Jennifer Lippincott-Schwartz, Juan Bonifacino, James Hurley, Michael Summers, Judith Levin, Eric Barklis, Asim Debnath, Simon Cocklin, Shan-Lu Liu, and Sriram Subramaniam, to name a few , 55–74.In 2014, Freed became Deputy Director of the HIV DRP (under then-Director Stephen Hughes) and in 2015 became Director of the HIV DRP, which was renamed the HIV Dynamics and Replication Program. Freed enjoys close scientific interactions with the other DRP PIs—Stephen Hughes, Alan Rein, Vinay Pathak, Wei-Shau Hu, Frank Maldarelli, Mary Kierney, and Alex Compton—and with DRP-associated investigators John Coffin and John Mellors.Viruses. He also serves as an Editor for Journal of Molecular Biology and is on the editorial boards of several virology journals, including Journal of Virology and Retrovirology. Starting in 2018, he is serving as an Associate Editor for Fields Virology. Freed has been an organizer for a number of international virology conferences, including the Cold Spring Harbor Retroviruses Meeting (2004); American Society for Cell Biology Conference on the Cell Biology of HIV-1 and Other Retroviruses (2006); the Keystone Meeting “Frontiers in HIV Pathogenesis, Therapy and Eradication” (2012); the Keystone Meeting “The Ins and Outs of Viral Infection: Entry, Assembly, Exit and Spread” (2014); two conferences sponsored by Viruses: “At the Forefront of Virus-Host Interactions  and “Breakthroughs in Viral Replication” ; and the International Workshop of the Structure and Function of the gp41 Cytoplasmic Tail . Freed is Co-Chair of the NIH Virology Interest Group and Co-Director of the University of Maryland Virology Program. In addition to ad hoc service on many national and international study sections and grant review panels, he was a member of the NIH AIDS Discovery and Development of Therapeutics (ADDT) Study Section from 2012 to 2017 and served as ADDT Chair from 2015 to 2017. The recognition of which Freed is perhaps most proud is an NCI Mentor of Merit Award for excellence in mentoring.Freed has long been an advocate for virology research and has worked to promote interactions among virologists. Since its launch in 2009, he has served as Editor-in-Chief of the open-access journal When not working, Freed enjoys running, hiking, skiing, biking, backpacking, fly fishing, and music, and spending time with his family.