Rounded shoulder (RS) posture causes neck and shoulder pathologies.Mechanical correction taping (MCT) is often incorporated into posturalcorrective therapies; however, its effects on muscle stiffness areunclear.We investigated the effect of MCT with different tape fabrics, along withexercise, on upper trapezius and pectoralis minor muscle stiffness and theposture of sedentary workers.A randomized controlled study was performed at Aydın Adnan MenderesUniversity, Aydın, Turkey.The study included 39 workers with RS posture. Two intervention groups(performance tape: PT and classic tape: CT) were taped twice a week andadministered a home exercise program for 4 weeks. The control (C) groupperformed only home exercises. RS was measured using an acromion-testingtable (AT), stiffness using shear wave elastography ultrasound, and shoulderangle (SA) using a smartphone application at baseline and 4 weeks. Time andgroup interactions were determined using 3 × 2 mixed analysis ofvariance.2 = 0.445) and SA (η2 = 0.325) in the PT and Cgroups (P < 0.05) and left upper trapezius stiffness (η2 =0.287) in the CT and C groups (P < 0.05). In the post hoc analyses, nodifference was noted between the groups from baseline to 4 weeks (P >0.05).Intragroup analyses revealed a significant main effect of time on AT distance(ηScapular MCT added to postural exercises did not show any difference betweenthe intervention groups and controls in terms of muscle stiffness andposture in sedentary workers. Rounded shoulder (RS) posture is a postural disorder in which the line ofgravity shifts anteriorly. This shift causes the head and shoulder positions to beinconsistent with the vertical line of the body, leading to “poor” posture. Poor posture of the head and shoulders is associated with the risk ofincreased muscle load, degenerative disc disease, back pain, and chronic shoulder pathologies. RS posture also develops with alignment impairments in the scapular position.A protracted and anteriorly tilted scapula creates excessive stress and increasesmuscle tone. According to the literature, the muscles with the highest increase in toneare the upper trapezius and pectoralis minor.Posture is defined as the sequence of body parts required to maintain musculoskeletal balance. loss of function and work efficiency in workers.Prolonged sitting in a static position increases poor posture. Therefore, thepossibility of developing poor posture is especially concerning in desk workers.Working in a static environment exacerbates the RS posture over time, causing Among these, scapular mechanical corrective taping with elastic tape is apopular technique. In a study using corrective taping, it was shown that this applicationsignificantly improved shoulder posture. In a systematic review, scapular corrective taping was suggested to improvescapular posture in both healthy individuals and patients with shoulder problems.Several different applications used for posture correction have been described in the literature. The shear wave elastography method has high reliability and providesobjective data by converting the stiffness of the muscle in a localized area intonumerical data. In the literature, there is no study explaining the effectiveness of scapularmechanical correction taping (MCT) on shoulder muscle stiffness using the shear waveelastography method. Therefore, it remains unclear whether corrective tapingregulates muscle stiffness in the long term.Muscle stiffness is considered valuable information in the diagnosis of neck andshoulder problems.Our primary hypothesis was that MCT applied in addition to exercise would decreasethe stiffness of the upper trapezius and pectoralis minor muscles and fix shoulderposture in workers with RS deformity. The secondary aim of this study was todetermine whether different tape fabrics affected the application results. The participants were excluded if they had a musculoskeletal systeminjury in the past 6 months or any neurologic or orthopedic disorder or cervicalradiculopathy, received physical therapy in the last 6 months, participated inprofessional sports, or had an allergic skin reaction to the tape material. Allprocedures were explained to the participants, and written informed consent wasobtained. Ethical approval for the study was obtained from the Ethics Committeeof Aydın Adnan Menderes University, Faculty of Health SciencesNon-Interventional Clinical Investigations , dated April 25, 2018.This study was conducted at a university hospital with 45 sedentary workers aged18–34 years. Participants were included if they had RS posture with reference toa prior screening using lateral acromion-testing table distance (AT distance)measurement. Based on the results of this test, individuals with a result of 3cm or more were considered to have RS posture, as shown in a previousstudy.www.random.org” was used. Theparticipants did not have any information about the groups formed or which groupthey belonged to. Therefore, a single-blinded study was performed. The studyincluded two intervention groups, classic tape  and performance tape, and one control group . Data were collected using asmartphone-based photographic analysis application, Dr. Goniometer , for shoulder angle (SA) and using shear wave elastography formuscle stiffness. Elastographic evaluations of the participants were performedby a radiologist at the Radiology Department of the same university. Workerheight (cm), weight (kg), and age (years) were recorded as demographicinformation.This study was a randomized controlled, single-blinded clinical study. Theparticipants were randomized using a computer-assisted randomization method. Forthis process, the sequence generator available at “ at least 42 individuals (14 for each group) were required to obtain 80%power with 95% confidence.Assuming that a strong degree of effect size (f = 0.5) was obtained for thedifference between the three groups as a result of the power analysis conducteda priori in the direction of hypothetical expectations with reference to asimilar study,At the first visit, all the participants underwent baseline measurements.Immediately after the first visit, the tape was applied to the participants inthe CT and PT groups. CT is a classical corrective tape made with a regularcorrective fabric. PT is a new form of corrective tape developed by the samebrand for the same purpose although with a different fabric. There is adifference in weaving between the different fabrics of the tape, allowing themto be thicker or thinner. The tapes of the participants in these groups werereapplied twice a week for a total of 4 weeks. The workers continued their homeexercise program for 4 weeks. The workers in the control group performed onlythe home exercise program. Measurements were repeated in the same order at theend of 4 weeks. The tape was removed during the final measurement. The tape was applied to left and right shoulder girdle. The same tapingtechnique was applied to the CT and PT groups using different tape fabrics. Before the measurement, the reference bone points (the acromion andseventh vertebra) were marked using a pen or a reflective marker to beclearly observed on the photograph. The camera was set up to take aphotograph of the participant from the right lateral side. The participantwas subsequently asked to lean forward and backward three times to relax andassume a comfortable standing position. While the participants breathedproperly and stood still, a point was marked on the wall directly oppositethe participant’s eye level to maintain posture. After taking the photo, thecursors on the application screen were adjusted, and the desired angle wasrecorded , and the stiffness of the upper trapeziusand pectoralis minor muscles was examined. A 4 cm transducer and a 9 MHzlinear probe were used for imaging. The ‘musculoskeletal present’ settingwas used. The probe was placed parallel to the muscle fibers. At least 10consecutive measurements were performed for each muscle, and the median wasobtained. For standardization, measurements with a quality factor of 0.4–1.0reliability measurement index were used in each muscle. Measurements belowthe 0.4 reliability measurement index are omitted. The test for the uppertrapezius muscle was performed while the participant was in a sittingposition with the hands resting on the thigh. For the pectoralis minor test,the participant was in the supine position with the arms resting on bothsides. The muscle shear modulus was recorded in kilopascals (kPas),considering that each assessment was taken at the same point, and the levelof probe pressure was equal.2) and Cohen’s d. Partial eta squared (η2) valueswere accepted as follows: 0.01 = small, 0.06 = medium, and 0.14 = large. Cohen’s d values were accepted as follows: < 0.20 = small, 0.21–0.50 =small and medium, 0.50–0.80 = medium and large, and > 0.80 = large. Significance level was set at P < 0.05.The Statistical Package for Social Sciences (SPSS)  was used for data analysis. For the threegroups  at two different times of assessment (at baseline and 4weeks), time and group interactions were determined using 3 × 2 mixed analysisof variance. For significant P values, Bonferroni corrections were used for posthoc analysis. Effect sizes were interpreted using partial eta squared included in the study are shown in 2: 0.445) and SA degrees in the PTand C groups  and inleft upper trapezius stiffness in the CT and C groups  (P < 0.05). However, in the post hoc analyses, noneof the evaluated parameters showed differences among the groups from baseline to 4weeks (P > 0.05)  .To our knowledge, this is the first randomized controlled study to investigate theeffects of MCT on muscle stiffness. After 4 weeks of mechanical scapular correctiontaping application, the results showed that the RS posture significantly decreasedin all groups; however, the SA was corrected only in the PT and C groups.Improvement in muscle stiffness was only observed in the left upper trapezius in theCT and C groups. No superiority was observed among the intervention groups andcontrols in terms of the evaluations. To prevent these shoulder problems during repetitive overhead movements, astable scapula and coordinated activity of the scapulohumeral muscles are required.Impairments in scapular movements during activities are associated with shoulderpain because they cause excessive stress and microtrauma to soft tissues. Scapular taping is one of the most useful methods for increasing jointstability by providing biomechanical realignment of the scapula and glenohumeraljoint during several activities. With this technique, which is applied using anelastic therapeutic tape, both the normal healing of soft tissues and the stabilityof the joints are supported without restricting the range of motion. In a systematic review, it was suggested that scapular corrective tapingcould be used to improve scapular posture in both healthy individuals and patientswith shoulder problems. A placebo-controlled study also reported a reduction in supine AT distancemeasurement for RS posture with mechanical scapular correction taping. On the contrary, in a study investigating the acute effect of bilateralscapular mechanical correction technique by using corrective and rigid tapes onposture in university students with significant shoulder protraction, no significanteffect was reported. Similarly, Gulpinar et al. used the mechanical correction technique with bothcorrective and rigid tapes to determine the acute effect on RS posture. They positioned the glenohumeral joint in external rotation using themechanical correction technique. They found an increase in the total range of motionof the shoulder in acute measurements; however, no change in posture was noted. The use of this technique is controversial in the literature. In thesestudies, posture was generally measured immediately after taping. In contrast, weevaluated the long-term effects in our study. The results were inconsistent withdifferent fabricated tapes. The SA did not change in the CT group; however, itsignificantly increased in the PT group. Intergroup analyses also showed that nosuperiority of scapular MCT on the SA over the controls was noted. Since thenumerical increase in the SA was mostly in the control group, we cannot concludethat the angular change was due to taping. We postulate that the exercise programhad the necessary effect.Deformities in soft tissue stiffness, muscle activity, and bone alignment may causealterations in scapular and humeral movement. Consequently, several conditions, suchas impingement, rotator cuff disease, joint instability, and capsulitis, may occur. In desk workers, upper trapezius stiffness was shown to increase as theinclination angle of the head changes. Like the upper trapezius, proper tension–length relationship and pectoralisminor stiffness are also associated with optimal scapular posture. Average stiffness values of the upper trapezius were calculated as follows:40–47 kPa in the sitting position and 0° neutral cervical position and 60–83 kPa in50° cervical forward flexion in healthy participants using the shear waveelastography method. Average pectoralis minor stiffness was also measured as 12.7 ± 3.6 kPa inhealthy individuals in another study. In our study, in the baseline measurements, upper trapezius stiffnessmeasured in the neutral position was found to be between 40 and 47 (±9–17) kPa inall groups, whereas pectoralis minor stiffness ranged between 15 and 34 (±14) kPa,similar to the study by Zhang et al. In this situation, scapular taping may be a useful technique to reduce thesymptoms. The tape can adjust the muscle activity through proprioceptivefeedback.Overactivation and stiffness of the upper trapezius and pectoralis minor musclesassociated with weakness of the lower trapezius and rhomboid muscles may cause arelatively protracted shoulder and disrupt normal posture. In our study, instead of reducing the muscle stiffness using a directapplication, we expected a decrease in stiffness that may occur secondary to posturecorrection with proprioceptive feedback. After 4 weeks of scapular MCT, asignificant decrease in left upper trapezius muscle stiffness in the CT and C groupswas noted; however, no intergroup superiority was observed. The pectoralis minorstiffness in the C group also numerically decreased; however, this was notstatistically significant. The decrease in the stiffness level of the uppertrapezius muscle in both the CT and C groups indicated that this decrease was notcaused by MCT. Thus, we can argue that a 4-week home exercise program regulatedmuscle stiffness by improving shoulder posture. In addition, although theparticipants included in this study had an RS posture, the initial stiffness valueswere similar to those in studies on healthy individuals. This may be another reasonwhy the decrease in stiffness levels was not significant. While there are studiesshowing the effectiveness of exercise on postural angles in the literature, nonehave evaluated muscular properties using shear wave ultrasonography. Kim et al.showed that McKenzie exercises were effective in increasing the craniovertebralangle and decreasing RS posture. Likewise, in another study, similar exercises were performed while MCT wasadded to the intervention group. In that study, it was shown that the greatestimprovement in craniovertebral angle occurred in the exercise group, and awell-planned exercise program was concluded to help improve posture. In the present study, the exercise program prescribed to all participantsincluded simple postural corrective exercises. The fact that no difference was notedbetween the groups showed that even a 4-week posture training with simple exercisescould achieve the same effect.It was reported that upper trapezius activity decreased and proprioception improvedin individuals who underwent scapular corrective taping.Our study had some limitations. First, we performed pre-screening using supine ATdistance measurement instead of angular measurement, while similar studies usedangular measurements as the inclusion criteria of the participants. We recommendusing postural angle data obtained by the photogrammetric method as an inclusioncriterion in future studies. Second, a healthy group was not included in the studyfor comparison. Thus, in future studies, the baseline measurements can also becompared with those of healthy individuals.Scapular mechanical correction using corrective taping in addition to a posturalexercise program was not found to be effective for muscle stiffness and posture inworkers with RS posture. Different fabrics of tape materials did not result insignificant changes. Therefore, prescribing corrective postural exercises will bemore effective for the treatment of muscle stiffness that develops secondary topostural disorders. Based on our study results, we do not recommend the use ofscapular MCT with the expectation of corrective and muscle stiffness regulatoryeffects in the long term.


Evidence that specific mortality of PCa decrease when clinically significant PCa (csPCa) is early detected has moved the focus of PCa screening towards csPCa.https://mripcaprediction.shinyapps.io/MRIPCaPrediction/.The recommendation of prostate biopsy is currently made according to the PI‐RADS category. Experienced radiologists, reporting with an updated version of PI‐RADS, obtain a negative predictive value of mpMRI that reaches up to 95%, which makes it possible to avoid prostate biopsies in men with suspected PCa with a PI‐RADS <3. MRI‐targeted biopsies of suspicious lesions (PI‐RADS ≥3) improve the sensitivity of systematic biopsies for csPCa. However, uncertain scenarios after mpMRI, having high rates of unnecessary biopsies and/or overdetection of iPCa, remain, and then PSA density (PSAD), new markers and predictive models are recommended to improve the selection of candidates for prostate biopsy.The present study aims to compare the current standard approach for early detection of csPCa, based on MRI‐targeted biopsies when PI‐RADS lesions ≥3 and systematic biopsy,A series of 946 men with serum PSA > 3.0 ng/mL and/or abnormal DRE was recruited prospectively in two academic centres of cities from the Barcelona metropolitan area (PSM and GTiP), between January 1 of 2018 and December 31 of 2021. This series was independent from those for the development of BCN‐RC 1 and BCN‐RC 2 recruited at VHH, between January 1 of 2016 and December 31 of 2019.The probability analyses of the standard approach and the proposed ROM are presented in Figure The proposed ROM was able to rule out almost one‐third of mpMRI exams and the percentage of saved biopsies increased from the 24.8% observed with the standard approach to the 28.2%, whereas the percentage of undetected csPCa decreased from 10.9 to 6.7 respectively. Remmers et al. have recently reported the results with an ROM based on sequencing the Rotterdam RC‐3 and the Rotterdam MRI‐RC in the MRI arm of the PRECISION trial, which was carried out in biopsy‐naïve men. After recalibration and adjustment of csPCa thresholds in both predictive models, this ROM was able to rule out 13% of mpMRI exams, decreasing the number of prostate biopsies in 9% and missing 8.5% of csPCa detected in the 134 men with PI‐RADS ≥3 in whom MRI‐targeted biopsies of suspicious lesions and systematic biopsy were performed.The present study confirms the effectiveness of the proposed ROM to improve the early detection of csPCa by reducing the demand of mpMRI exams and unnecessary prostate biopsies. The missing rate of csPCa of the standard approach that avoids systematic biopsy in men with negative mpMRI also decreased. The main limitation for the use of the proposed ROM is the need of validation in the populations where it will be implemented. Now, following the recommendation of EAU, this ROM is ready to be used in the metropolitan area of Barcelona, and validation in Catalonia (Spain), a country with seven and half million inhabitants, is ongoing. Ideally, a randomised trial would be necessary to generate high evidence level.Juan Morote, Ángel Borque‐Fernando and Luis M. Esteban conceptualised the idea. Marina Triquell, José M. Abascal, Pol Servian, Jacques Planas, Olga Mendez and Enrique Tilla developed the concept. Juan Morote wrote the first draft of the manuscript. All authors were involved in editing, critical review and final approval of the manuscript.The authors have no conflict of interest to declare.


Since their introduction, there has been limited research regarding the mechanical properties of novel strength-gradient monolithic zirconia. In addition to that, studies evaluating the effect of different core-build materials on the strength of indirect restorations are scarce. Therefore, the aim of this study was to investigate the effect of using different core build-up materials on biaxial flexural strength of a new monolithic multilayered zirconia material.n = 20). Forty composite discs were prepared from Tetric N-Ceram  and MultiCore Flow . The zirconia discs were adhesively cemented to the 2 types of composite forming 2 groups (Zirconia-Tetric N-Ceram and Zirconia-MultiCore Flow). Biaxial flexural strength was determined using a piston-on-3-ball test. The data were statistically analyzed with an independent t-test for significant differences (p = 0.05).Forty zirconia discs were fabricated from IPS e.max ZirCAD Prime  and divided into 2 groups (p < 0.001) but no statistically significant differences were found in strength values between Zirconia-Tetric N-Ceram and Zirconia-MultiCore Flow bilayered samples (p = 0.27).Tetric N-Ceram had significantly higher strength than MultiCore Flow (It was concluded that although the tested composite core materials significantly differ in their biaxial flexural strength values, they had no influence on the biaxial flexural strength of the overlying zirconia. Despite the increased awareness of the importance of dental and oral health, the need for endodontic treatment is still high . SeveralCore restorations used for endodontically treated teeth should restore the normal anatomical form of teeth in addition to improving the compressive and tensile strengths to resist functional and para-functional stresses . DiffereFollowing the direct restorations, full coverage indirect restorations are recommended for severely damaged teeth with large structural loss to provide cuspal protection for endodontically treated teeth . DiffereThe first generation of dental zirconia (3 Y-TZP) was the high-strength tetragonal crystalline phase, stabilized with 3 mol% yttria and enhanced with 0.25% alumina and used as core material . Due to Flexural strength is a significant characteristic of brittle materials like ceramics due to its ability to determine their durability and longevity . BiaxialLimited number of studies have been undertaken to evaluate the clinical performance of novel strength-gradient monolithic zirconia and studies evaluating the effect of different core-build materials on the strength of indirect restorations are scarce. Therefore, the aim of this study was to investigate the effect of using different composite core build-up materials on the flexural strength values of new highly translucent zirconia materials. The null hypotheses tested were that there is no statistically significant difference in biaxial flexural strength values between monolithic strength-gradient zirconia restorations cemented to 2 different composite core materials and that there is no statistically significant difference in values of biaxial flexural strength of the 2 composite core build-up materials tested.n = 20). Table Forty bilayered disc-shaped specimens fabricated from monolithic strength-gradient zirconia material , shade A2, and cemented to 2 composite core build-up materials using phosphate monomer containing resin-cement Multilink Automix  were evaluated in this study. Based on a power analysis which showed that for α = 0.05, power = 0.8, 40 disc-shaped monolithic zirconia specimens and 40 disc-shaped composite core specimens were fabricated; 20 for each group  [For the composite core material, 20 disc-shaped specimens of 10mm diameter and 4mm thickness for each group were prepared using a customized resin mold  that was designed with specific dimensions based on the digitized data  using CAD software  and printed using 3D printer . For the first group, Tetric N-Ceram , shade IVA, was applied in 2 increments for a total thickness of 4 mm into the resin mold until completely filled then carefully condensed with ST instrument with a plastic working end  . For theMN, USA) , 40.2O3-powder at 0.1 MPa pressure at constant distance of 10mm for 15 s , followed by ultrasonic cleaning in isopropanol bath for 5 min and air-drying for 15 s [The 40 disc-shaped zirconia specimens  were designed using CAD software  based on the digitized data and manufactured from partially sintered monolithic zirconia using a five-axis milling machine . The location of the cut was made through the middle layer of zirconia blocks. After separation from the blank, the samples were finished using finishing burs . The enlarged green-state specimens were then sintered using a special furnace  according to the recommended manufacturer sintering protocol at a temperature of 1,500°C for about 4.5 h. The sintered specimens were then finished using finishing burs  then abraded with 50 μm Alfor 15 s .Two uniform coats of a phosphate-containing primer  were applied directly to the abraded zirconia specimens just before cementation, gently air-dried for 10 s, and light polymerized for 20 s .Consequently, self-etching, dual-cure Multilink Automix resin-cement was used for cementation of the samples according to the manufacturers’ instructions. Resin-cement was applied from a syringe using automatic mixing tips to the intaglio surfaces of the zirconia specimens . ThereafAll specimens were subjected to the biaxial flexural strength test at the universal testing machine  according to ISO 6872:2008 for dental ceramics , 45. TheFor the piston-on-three-ball test, the sample holder was made of 3 hardened steel balls with a diameter of 3.2mm each. The steel balls were positioned at 120° apart forming an equilateral triangle on a support circle with a diameter of 10mm. The center of the specimens, which were placed upon the steel balls, and the center of the equilateral triangle were aligned coaxially. The load was applied centrally through a flat piston, with a diameter of 1.4mm, at a crosshead speed of 1mm/min until failure .The load at fracture (P) was determined when a dramatic drop in the applied load occurred, associated with acoustic sound and values were recorded in Newton (N). Figure The biaxial flexural strength values in the zirconia and composite layers of the bilayered specimen were calculated using the following formulas derived by Hsueh et al. :\documenFor this study, a = 5mm, c = 0.7mm, R = 5mm, t1 = 4mm, t2 = 2mm, z1 = 0, z2 = 2mmIn addition, Hsueh and Kelly provided analytical solutions for calculating the stresses at the outer surfaces of the discs, (bottom) :\documenFurthermore, stresses at composite and zirconia interfaces, Analytical data calculations were carried out using the SPSS version 26.0  statistical program. The results were statistically analyzed using the independent t-test . All data were subjected to Levene’s test of homogeneity of variance (α < 0.05) following the assumption of equal variance. A statistical significance was determined given a p-value less than 0.05 (2-tailed). The mean biaxial flexural strength values of the 2 zirconia groups, the mean biaxial flexural strength values of the 2 composite core materials, the mean stresses at the top and bottom of the bilayered specimens for each group, and the mean interfacial stresses at the zirconia and composite core layers for each group were calculated, analyzed, and compared for any statistically significant differences. In addition, the biaxial flexural strength values for each zirconia group were also analyzed using Weibull statistics  to evaluate the flexural strength’s reliability and to estimate characteristic strength (σo) as well as the Weibull modulus (m) according to the following equation:Pf = 1 − expPf is the probability of failure, σ is the fracture strength, σ0 is the characteristic strength, and m is the Weibull modulus.Where The visual analysis of the fractured specimens revealed 1 type of failure for all bilayered specimens in both groups: complete fracture, through the zirconia and composite core layers. An example of the fractured specimen is shown in Fig. p > 0.05). No statistically significant difference in the biaxial flexural strength values of the 2 zirconia groups cemented was found (p = 0.27). Higher Weibull modulus value was obtained for the Zirconia-Tetric N-Ceram compared to the Zirconia-MultiCore Flow. Three-point flexural strength results and characteristic strength values for the 2 tested zirconia groups were in the same order. The Weibull statistical analysis of the biaxial flexural strength data is summarized in Table The Kolmogorov–Smirnov test revealed no deviation from the normal distribution and data were analyzed parametrically (p < 0.001). Furthermore, for both tested groups, the stress values at the top layers were higher than the stress values at the bottom layers and the interfacial stresses at the zirconia layers were higher than the interfacial stresses at the composite core layers.Comparing the biaxial flexural strength values of the 2 tested composite core materials, Tetric N-Ceram had a significantly higher biaxial flexural strength values compared to MultiCore Flow (p = 0.12), the Zirconia-MultiCore Flow group had significantly higher stresses values at the top layer and at the interfacial zirconia layer ((p < 0.001), p = 0.008 respectively) but significantly lower stress values at the bottom layer (p < 0.001).Although no statistically significant differences were found in the interfacial stresses at the composite core layers between the 2 tested groups (These results are summarized in Table p = 0.270), hence the first null hypothesis was accepted. However, Tetric N-Ceram had significantly higher biaxial flexural strength than MultiCore Flow (p < 0.001) and therefore the second null hypothesis was rejected.The present study investigated the biaxial flexural strength of 2 different composite core materials (Tetric N-Ceram and MultiCore Flow) and their influence on the biaxial flexural strength of monolithic multilayered strength-gradient zirconia restorations. The results showed no significant effect of the composite core materials on the biaxial flexural strength of the zirconia specimens , p < 0.001 respectively). This can be attributed to the different chemical composition of Tetric N-Ceram and MultiCore Flow along with the lower modulus of elasticity, and stiffness of MultiCore Flow compared to the Tetric N-Ceram. Although no statistically significant differences were found in the interfacial stresses at the composite layers between the 2 tested groups (p = 0.12), variation in the chemical composition and the mechanical properties of Tetric N-Ceram and MultiCore Flow resulted in higher interfacial stress at the zirconia layer in the Zirconia-MultiCore Flow (p = 0.008) [When the prepared bilayered specimen is composed of 2 distinct layers with different moduli of elasticity, large stresses usually emerge. Two different stress zones arise through the thicknesses of the discs: the compressive force zone at the top layer and the tensile force zone at the bottom layer which is more critical since it induces more problems than compressive stresses for brittle materials as ceramics , 36. Fur= 0.008) .All specimens in our study exhibited 1 type of failure which was complete fracture through the entire bilayered specimen that seemed to act as a homogenous material without any sign of delamination or separation. This immediate fracture occurs when interfacial toughness is greater than the flexural stresses in the tension surface at failure and because the strengths at the bottom surface of the bilayered specimens (stress2) .E = 10.8) has a higher modulus of elasticity compared to the MultiCore Flow (E = 7). However, this disagrees with the results of some studies that found that variations in the moduli of elasticity had no influence on fracture resistance and flexural strength as multiple factors might also contribute to the overall strength of the material including the resin matrices, different types of fillers, or filler size and their distribution [Core buildup materials used to restore fractured, broken, and endodontically treated teeth should be of satisfactory strength to resist stresses during function and mastication . The coraterials . This miaterials . Furtherribution , 39. Warribution .One of limitations of our study was the absence of tooth substrate. However, previous studies proved the reliability of using the piston-on-three-ball test for studying the biaxial flexural strength of brittle dental materials such as ceramics . FurtherTetric N-Ceram composite core material have superior biaxial flexural strength than MultiCore Flow material.The type of core material used to restore endodontically treated teeth does not affect the biaxial flexural strength values of the overlying zirconia restorations.IPS e.max ZirCAD Prime has high biaxial flexural strength value allowing its use for the construction of anterior and posterior indirect restorations.Within the limitations of this in vitro study, the following conclusions can be withdrawn:


Retention and support are needed for removable partial denture stability. The stability can be achieved by clasps, occlusal and cingulum rests on healthy abutment teeth. However, implants or crowns can be used to support the removable partial denture instated on unhealthy abutment teeth. This study was conducted to investigate the fracture strength of two types of all-ceramic restorations used as abutments for the removable partial denture framework. The crowns were manufactured with two types of ceramic materials: zirconia and IPS e.max Press ceramics. The metal alloy  was cast to form the removable partial denture framework. A universal testing machine was used to evaluate the fracture strength of both ceramic crown materials. The results presented no fractures in all-ceramic crowns, but deformation of the partial denture frameworks occurred. With the limitation of this study, it can be concluded that zirconia and IPS e.max Press ceramic can be used as abutments to provide adequate support to the removable partial denture. Partially dentate problems are still present in dental clinical practices. An increase in these problems means that, over time, patients may lose more than one tooth and become partially dentate. These scenarios will generally increase the demand for dental prosthodontics . This inThe patient’s age can affect the success of the dental implant treatment. The elderly have less healing time due to the decreased formation of new bone around an implant . TherefoDespite the effect of the RPD on the periodontal condition and other problems, for instance, pain in the soft tissues, especially with free-end saddles , RPD is Due to the disadvantages such as color and biocompatibility, the demand for aesthetic materials such as all-ceramics is increasing. Despite dental ceramic materials’ high performance and strength, fractures are commonly reported with this type of restoration . ClinicaIn addition, fracturing of all-ceramic restorations can be caused by a load of biting forces exerted, particularly in the posterior areas . NumerouLimited previous studies were found to investigate the fracture strength of all-ceramic restorations for removable partial dentures. For this reason, this study aimed to investigate and compare the fracture strength of two selected types of all-ceramic restorations involved in the removable partial denture framework.Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) was used to mill the final restoration, such as zirconia samples or wax with IPS e.max Press and RPD samples, to standardize the sample fabrication and dimension ,29,31,33A unilateral edentulous space with natural teeth remaining in both anterior and posterior models, known as class III modification 1, was selected for this study . The selThe duplicated model was trimmed until it reached the target area, the edentulous area between two prepared teeth . . The selThe crowns were designed on the digitally scanned model with these measurements ) using Amman Girrback Ceramill 600 software. Two ceramic materials were used to fabricate all-ceramic crowns (IPS e.max Press lithium disilicate glass ceramics and zirconia).For the IPS e.max empress, the designed crowns were milled into the wax using the CAM process (milling manufacturing). The wax crowns were then sprued, invested, cast, divested, finished and glazed according to the manufacturer’s instructions for the IPS e.max Press ceramic materials .For zirconia materials, the designed crowns were milled into the zirconia using the CAM process (milling manufacturing), and the zirconia crowns were sintered according to the manufacturer’s instructions.All IPS e.max Press and zirconia crowns were cemented into the resin models using 3M ESPE Relyx luting Cement and scanned for the RPD framework  design.The RPD framework was designed using the digitally scanned model with the default thickness of the saddle and occlusal rests area ) using Amman Girrback Ceramill 600 software. Moreover, a distance of approximately 3 mm was created between the saddle and the alveolar ridge to allow the universal testing machine crosshead to be generated when the load is applied . The desAll the samples were subjected to the test by a universal testing machine . A single fracture load was applied at a rate of 1 mm/min to investigate the fracture strength of both ceramic crown types (IPS e.max Press ceramics and zirconia) for RPDs.Twenty samples were fabricated; each had two all-ceramic crowns connected by the removable partial denture saddle framework, with two occlusal rest seats on the abutment crowns merged distally in the first premolar and mesially in the second molar .Ten samples from both groups (IPS e.max Press and zirconia) were subjected to the test by a universal testing machine to compare each group’s mean fracture strength. The results showed no fracturing of ceramic crowns for both groups after applying a single cycle of fracture strength test at a 1 mm/min rate, which prevented the results from being recorded, and these result were excluded.For the RPD saddles with both ceramic crowns, a deformation was observed. This could be related to the differences in design and weak mechanical properties (modulus of elasticity and tensile strength) of Co-Cr compared to all-ceramic restorations .The maximum load of the RPD framework with the zirconia group was at 400 N with a maximum deflection of 1.9409 mm. However, the minimum load was at 206 N with a maximum deflection of 1.9014 mm .For the RPD framework with the IPS e.max Press group, the maximum load was at 374 N with a maximum deflection of 2.3335 mm, while the minimum load was at 174 N with a minimum deflection of 1.1745 mm .p ≤ 0.05) (The mean fracture strength of zirconia crowns from the previous research  was sign ≤ 0.05) p ≤ 0.05) (The mean fracture strength of zirconia crowns from the previous research  was sign ≤ 0.05) . This in ≤ 0.05) .p ≤ 0.05) (The mean fracture strength of IPS e.max Press crowns from the previous research  was sign ≤ 0.05) . This in ≤ 0.05) .This study was carried out to investigate and compare the fracture strength of two types of ceramic restorations involved in the RPD framework and determine which type of ceramic restoration can be used to support the RPD framework.Twenty samples were fabricated and divided into two groups: group A zirconia crowns and group B IPS e.max Press crowns. The CAD/CAM technology was used to fabricate all crowns with similar dimensions according to the previous study by Jang et al. ,35 with A variety of studies have investigated all-ceramic restorations under the fracture fatigue resistance or until fractures occurred ,37,38, yOne factor that affects fracture test performance is the firmly located samples in the testing machine during the test. One of the IPS e.max Press crowns failed the test due to the improbably located occlusal rest, which led to the move and sliding of the RPD saddle during the test. That was not expected, as all samples were designed and fabricated using CAD/CAM. It was assumed that the RPD saddles would be accurate enough to obtain acceptable results. This assumption was related to the findings of a previous study, indicating that the adaptation of CAD/CAM fabricated dentures would be more accurate compared to the conventional methods . It is wAll saddles in this study were designed by the Amman Girrback Ceramill software. The designed saddle and occlusal rest area dimensions were as follows: thicknesses of 1.2 mm and occlusal rest thinness preparation of 1.2 mm . The strength of any material may be affected by modified dimensions and design applied to the RPD and Co-Cr component, particularly for the cingulum and occlusal rest seats. This was confirmed in Sato et al.’s  report oCo-Cr alloy was used and selected for the RPD framework in this study because of its biocompatibility, mechanical and physical properties. Furthermore, Co-Cr alloy is the most used and affordable material for the RPD framework. The maximum fracture load was recorded on the RPD with the zirconia group at 400 N, while the minimum was with IPS e.max Press at 174 N. This can be related to the difference in mechanical strength between the ceramics used in this study (zirconia and IPS e.max Press).Furthermore, the alloy material type and composition impact the outcome result according to Gapido et al.’s  study onLastly, the fracture test in this study was applied to the saddle area between the first premolar and second molar, which have been selected due to the maximum forces found in these regions according to the previous study. However, the outcomes might be changed using anterior teeth because of the different masticatory forces ,46,47,48With the limitation of this study, it can be concluded that all-ceramic restorations (zirconia and IPS e.max Press crowns) can support the framework of removable partial dentures, confirming this study’s hypothesis. Further studies of the all-ceramic restorations’ ability to support the removable partial denture framework of different materials and design is required.


The purpose of this study was to perform an integrative review on laser texturing the inner surface of lithium disilicate-reinforced glass ceramic or zirconia to increase their bond strength to resin-matrix cements.A bibliographic review was performed on PubMed using the following search terms: “zirconia” OR “lithium disilicate” AND “laser” AND “surface” OR “roughness” AND “bond strength” AND “luting agent” OR “resin cement.” Studies published in English language until March 15, 2023, were selected regarding the purpose of this study.4 laser irradiation were slightly higher (~ 33.5 MPa) than those recorded for grit-blasted zirconia surfaces (28 MPa). Laser-textured zirconia surfaces on CO2 laser revealed higher SBS values (18.1 ±0.8 MPa) than those (9.1 ± 0.56 MPa) recorded for untreated zirconia surfaces. On lithium disilicate-reinforced glass ceramics, higher SBS values to resin-matrix cements were recorded for specimens textured with a combination of fractional CO2 laser irradiation and HF acid etching (~ 22–24 MPa) when compared with grit-blasted specimens (12.2 MPa). Another study revealed SBS values at around 27.5 MPa for Er:YAG-textured lithium disilicate-reinforced glass ceramics to resin-matrix cements.A total of fifty-six studies were identified althoug thirteen studies were selected. The findings revealed that zirconia surfaces were significantly modified after laser irradiation resulting in macro-scale aligned retentive regions with depth values ranging from 50 to 120 µm. Average roughness values of laser-textured zirconia by Er,Cr:YSGG laser (~ 0.83 µm) were quite similar when compared to grit-blasted zirconia surfaces (~ 0.9 µm) although roughness increased up to 2.4 µm depending on the laser type and parameters. Lithium disilicate-reinforced glass ceramics textured with Er:YAG revealed an average roughness of around 3.5 µm while surfaces textured using Nd:YAG laser revealed an average roughness of 2.69 µm; that was quite similar to the roughness values recorded for etched surfaces (2.64 µm). The shear bond strength (SBS) values of zirconia surfaces textured on Nd:YVOThe laser irradiation at high power increases the roughness of the inner surface of lithium disilicate-reinforced glass ceramic or zirconia leading to an enhanced bond strength to resin-matrix cements. Thus, the laser type and irradiation parameters can be adjusted to enhance the macro- and micro-scale retention of zirconia and glass ceramic surfaces to resin-matrix cements.Alternative methods for surface modification of lithium disilicate-reinforced glass ceramic and zirconia surfaces have been assessed to provide proper morphological aspects for enhanced adhesion to resin-matrix cements. An increase in the bond strength of glass ceramics or zirconia to resin-matrix cements can improve the long-term performance of cemented prosthetic structures in the oral cavity. Titanium abutment base can also be modified by grit blasting with alumina particles (Al2O3) followed by acid etching with (5–10%) HF acid and then conditioning with silane and methacrylate-based adhesives , and Nd:YVO4 [2 laser ranged from 3 up to 20 W [Of the 13 selected studies, yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) were assessed by 9 studies –32 altho Nd:YVO4 . The las Nd:YVO4  while Er Nd:YVO4 –35. The 2 ,32,35,,  to 20 W . After l to 20 W , 32, 34 4 laser resulting in aligned retentive regions with macro-scale depth values ranging from 50 up to 120 µm [The surfaces of the zirconia were significantly modified after laser irradiation with Yb-doped fiber or Nd:YVOo 120 µm .The average roughness of laser-textured surfaces using Yb-doped fiber laser system was recorded at around 2.4 µm that was significantly higher when compared to the untreated zirconia surfaces (~ 0.2 µm). Nevertheless, the average roughness recorded for laser-textured surfaces using Er,Cr:YSGG (~ 0.83 µm) was quite similar to those recorded for grit-blasted zirconia surfaces (~ 0.9 µm) .Surfaces of lithium disilicate-reinforced glass ceramics were also modified by laser irradiation although the etching with HF acid resulted in high mean values of roughness . Lithium4 laser were slightly higher (~ 33.5 MPa) than those recorded for grit-blasted zirconia surfaces (28 MPa) [2 laser revealed the highest SBS values (18 ±0.8 MPa) while lowest values (9.1 ± 0.56 MPa) were recorded for untreated zirconia surfaces [Laser-textured zirconia surfaces showed high values of shear bond strength (SBS) to resin-matrix cements , 27. Theurfaces 2 MPa [2 l2 laser irradiation and HF acid etching (~ 22–24 MPa) when compared with grit-blasted specimens (12.2 MPa) [2O3 particles showed the lowest mean bond strength to the resin composite (15.62 MPa) [On lithium disilicate-reinforced glass ceramics, higher values of SBS to resin-matrix cements were recorded for specimens textured with a combination of fractional CO2.2 MPa) . Another2.2 MPa) , 34. Sur.62 MPa) .The main findings of the selected studies can be drawn as follows:This review reported relevant findings on laser-textured lithium disilicate-reinforced glass ceramic or zirconia surfaces and their adhesion to resin-matrix cements. Results showed an increased roughness of the glass ceramics and zirconia when compared to untreated surfaces. Thus, high values of roughness reveal an increase in the retentive area to silane agents, adhesive systems, and resin-matrix cements. Indeed, those findings validate the hypothesis of the present review. Nevertheless, different types of laser and irradiation parameters are reported in literature. A detailed discussion on laser parameters as well as on zirconia and glass ceramics and their adhesion to resin-matrix cements is given as follows.2, and Nd:YVO4) and irradiation parameters (Table 2 laser irradiation (wavelength of 10.6 mm) at a pulse repetition rate of 1000 Hz and pulse duration of 160 ms at an average power setting of 3 W and at 1 mm away from the surface [Previous studies revealed the surface modification of zirconia and glass ceramics by using different laser types  was assessed using a femtosecond laser, and the SBS values of Y-TZP to resin cement  were measured . The SBS studies .p = 0.2155).A previous study also assessed the effects of thermal cycling on the SBS values of laser-textured zirconia surfaces to resin-matrix cements. Y-TZP was textured on Yb-doped laser irradiation at a pulse repetition rate of 60 Hz and pulse duration of 6.6 s and at an average power setting of 24 W . Then, l4 laser irradiation (wavelength of 1065 nm) at 70 kHz from 60 mm away to the surface [In a previous selected study, Y-TZP or Ce-TZP surfaces were modified on Nd:YVO surface . Morphol surface . The rou surface . There w surface .Fig. 2Sc2O3 into ZrO2 formulations [1/2, flexural strength values at around 1200 MPa, and hardness at 1.1 GPa [2), magnesium oxide , and calcium oxide  [Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) are produced by introducing 2–5 mol% Yulations , 38 for  1.1 GPa , 40. Alsia, CaO) , 38. Theia, CaO) –42. Neveia, CaO) –43. Thus2-Li2O-K2O-ZnO-Al2O3-La2O3-P2O5 glass system [1/2, bend strength values around 320 ± 30 MPa, and hardness at 5.5 ± 0.3 GPa [Lithium disilicate-reinforced glass ceramic contains approximately 65% volume fraction of lithium disilicate crystals, 34% volume fraction of residual glass, and 1% volume fraction of porosity after heat treatment . The glas system , 46. Lit 0.3 GPa –47. Such2 laser irradiation (wavelength of 10.6 µm) at two different irradiation intensities (10W and 28 J or 20 W and 28 J) at a pulse repetition rate of 200 Hz and pulse duration of 1.7 ms or 0.58 ms [2 laser irradiation and HF acid etching . Grit-blasted specimens exhibited the lowest shear bond strength (12.2 MPa) to resin-matrix cements [In a previous study, lithium disilicate-reinforced glass ceramics were textured on CO 0.58 ms . Surface 0.58 ms . The hig cements . Considep < 0.05), although there was significant correlation between the ceramic systems. Grit-blasted plus laser-textured surfaces showed the highest mean SBS values for both ceramics groups. Atomic force microscopy images revealed a rough morphological aspect for grit-blasted surfaces [Another previous study reported the influence of grit blasting, acid etching, and laser irradiation on the shear bond strength of lithium disilicate-reinforced glass ceramic  and a feldspar-based porcelain  to a resin-matrix cement  . Each ofsurfaces .In another study, lithium disilicate-reinforced glass ceramic was also modified by Er:YAG  or Nd:YAG  pulsed laser irradiation . Groups Nowadays, ceramics and glass ceramics are used to synthesize metal free  and metal ceramic  for implant- or teeth-supported prostheses Fig. . On teetEven though a limited number of studies in literature, the selected studies reveal noteworthy data on laser-textured lithium disilicate-reinforced glass ceramic or zirconia surfaces and their adhesion to resin-matrix cements. In fact, several laser protocols have been assessed to enhance the retentive morphological aspects and increase the roughness for adhesion of ceramics and glass ceramics to resin-matrix cements. Indeed, the variability of laser types and irradiation parameters brings a broad data on the efficiency of the laser-assisted methods for surface modification of zirconia and glass ceramics. Also, further studies are performed to validate the effects of different laser parameters, restorative materials, and types of resin-matrix cements. Laser-assisted methods have been increasingly gathering attention in the technological field although most of laser apparatus are still quite expensive for clinical or laboratory application.2 laser irradiation and HF acid etching when compared with grit-blasted specimens. In fact, the association of traditional surface modification methods and laser-texturing provide beneficial effects for adhesion of glass-ceramics to resin-matrix cements.On lithium disilicate-reinforced glass ceramics, higher shear bond strength values to resin-matrix cements were recorded for specimens textured with a combination of fractional CO2 or Nd:YVO4 laser revealed higher shear bond strength to resin-matrix cements than those recorded for untreated zirconia surfaces. Thus, laser texturing approaches can become an alternative method for the modification of zirconia surfaces.Laser-textured zirconia surfaces on COThe laser irradiation at high power increases the roughness of the inner surface of lithium disilicate-reinforced glass ceramic or zirconia veneers and crowns leading to an enhanced bond strength to resin-matrix cements. Thus, the laser type and irradiation parameters can be adjusted to enhance the macro- and micro-scale retention of zirconia and glass ceramics surfaces. Further studies should consider other parameters related to the power output, frequency, and mode as well as the fluence of the laser irradiation to establish a standard guidelines for laser-texturing.Within the limitations of the selected studies, the main outcomes can be drawn as follows:


States Parties to the 1966 International Covenant on Economic, Social and Cultural Rights (ICESCR) have explicitly recognized the “benefits to be derived from the encouragement and development of international contacts and co-operation in the scientific field” in Article 15(4) of the Covenant.In its General Comment No. 25 published in 2020, the Committee on Economic, Social and Cultural Rights (CESCR) posits that this provision “reinforces” the general “duty to cooperate internationally toward the fulfillment of all economic, social and cultural rights” as established in Article 2 ICESCR and in Articles 55 and 56 of the United Nations (UN) Charter  and 15(4) ICESCR are notoriously unclear on this point  and 15(4) ICESCR and Articles 55 and 56 UN Charter on the same plane and by drawing what it refers to as a single “reinforced duty of international cooperation” expressly from their conjunction.So-doing, the CESCR misses the opportunity not only to clearly establish, once and for all, the legal bindingness of the duty of international cooperation it grounds in the RPEBSPA, but also to spell out the multiple specific duties of international cooperation that correspond to the four “dimensions” of the duty it distinguishes.Moreover, the Committee also contributes to the conflation between the transnational or international dimension of the duty of cooperation with other States that arises under the RPEBSPA, on the one hand, with the extraterritorial application of that duty, on the other. Most extraterritorial obligations are not duties of international cooperation, however. They require a State to act individually to protect human rights when it has effective control over right-holders situated on another State's territory.A second feature in the CESCR's treatment of the duty of international cooperation in General Comment No. 25 is its lack of specificity on the content of that duty.inter alia by facilitating air travel, data sharing arrangements and accessibility of educational resources (see text footnote 2). In order to prevent and mitigate the potentially harmful effects of science and technology and their applications on a transnational scale, the Committee posits that States “should promote multilateral agreements” to organize robust international cooperation.True, the Committee is quite concrete in relation to the first and the fourth “justifications and dimensions” of international cooperation in the scientific realm. In relation to nurturing science as a universal endeavor, the CESCR comments that States should promote and enable scientists' participation in the international scientific and technological community, Moreover, with respect to the third dimension of the duty of international cooperation that relates to the sharing of the benefits and applications of scientific progress with the international community, the CESCR refrains from specifying the content of the relevant duty.More generally, one may quibble about the choice of the term “dimensions” of the duty of international cooperation. It may have been better to refer to four actual “types” of duties of international cooperation. The fact that the Committee also refers to those four dimensions as “justifications” is indeed a clear indication of the need to ground them normatively as duties under the RPEBSPA and hence to link their content to their object of protection. In any case, those four dimensions of the duty of international cooperation overlap , and it is unclear whether they are exhaustive of international cooperation in the field of science. It remains to be determined, moreover, whether all duties arising under the RPEBSPA also have a cooperative dimension, including an international one.Last but not least, one particularly striking omission of the General Comment in this regard is its failure to engage with the positive cooperative duty to build international institutions for scientific cooperation with other States. That duty was mentioned as early on as 2009 by the UNESCO's Venice Statement as the duty “to establish institutions to promote the development and diffusion of science and technology”A third indeterminacy relates to the question of who should cooperate with whom, that is of the bearers of the duty of international cooperation under the RPEBSPA.In relation to the second justification for the duty of international cooperation, i.e. the disparities among States in science and technology, the CESCR distinguishes between “developing” and “developed” States.stricto sensu and the “responsibilities” of international cooperation.qua effective control over them, responsibilities for human rights are not owed to the right-holders, but to other States as erga omnes partes duties and arise under all ICESCR rights including the RPEBSPA. More precisely, the latter include responsibilities to cooperate and assist the duty-bearing States in complying with their own  duties under the RPEBSPA.Importantly, by identifying a single “duty” of international cooperation owed under Article 2(1) ICESCR and Articles 55 and 56 UN Charter and one that is “reinforced” by Article 15(4) ICESCR, the CESCR fails to distinguish between the “duties” of international cooperation Failing to distinguish between those duties and responsibilities to cooperate internationally prevents the Committee from addressing the multiplicity of duty- and responsibility-bearers of international cooperation under the RPEBSPA. More specifically, it cannot distinguish between the duty-bearing public institutions, such as States and IOs, and the additional and concurrent responsibility-bearers. The latter include States or IOs that do not have  jurisdiction over the respective right-holders, but also private persons  or institutions .By extension, General Comment No. 25 is also silent on the allocation of duties and responsibilities between those multiple cooperation duty-bearing States and/or public institutions, on the one hand, and between them and other responsibility-bearers, on the other. The CESCR merely begs the question when it refers to securing persons in other States an “adequate” access to scientific results (see text footnote 22). Here again, one may regret the lack of concern by the CESCR for the institutionalization of international cooperation and for how international institutions could help co-specify and co-allocate duties and responsibilities among the multiple duty-bearers and/or responsibility-bearers.In response to those three critiques of the General Comment No. 25, this section makes two proposals to dispel the indeterminacies surrounding the duty of international cooperation arising under the RPEBSPA: grounding the separate legal duties and responsibilities of international cooperation; and building international institutions to co-specify and co-allocate duties and responsibilities between their multiple bearers.To dispel the first indeterminacy criticized in Section 2.1, it is important to ground, i.e., justify, the separate legal duties and responsibilities of international cooperation.together.One way of doing so is to ground them specifically in the international public good of science. As one of this piece's authors has argued elsewhere, indeed, a key specificity of the duties and responsibilities corresponding to the RPEBSPA stems from their pertaining to a public, participatory and communal good. Their bearers do not merely owe them individually as they would were the protected interest individual only, but also bear those duties collectively. What this means is that States and IOs owe their respective individual duties and responsibilities relative to the RPEBSPA duties arising under the RPEBSPA is two-pronged: it resides in the universal scope of the public good of science and, by extension, in the universal scope of the standard threats to the interests in that good.More specifically, the justification of the collective and hence cooperative dimension of the The proposed justification of the legal duties of international cooperation arising under the RPEBSPA is consistent with the General Comment No. 25′s reference to science as “universal endeavor”. It also fits and justifies the distinction the CESCR makes between different “dimensions” of the duty of international cooperation. It seems, indeed, that three of the four dimensions of the duty of international cooperation identified by the CESCR correspond to the three dimensions or duties one usually identifies as arising under the RPEBSPA:responsibilities for the RPEBSPA that should be regarded as cooperative in the same way as the corresponding duties. It is the pivotal importance of those responsibilities to cooperate for the human right to participate in the international public good of science that explains the separate and explicit, and hence “reinforced” reference to “international assistance and cooperation” in Article 15(4) ICESCR.The same may be argued for the The proposed interpretation of the responsibilities to cooperate grounded in the RPEBSPA is consistent with the second “dimension” of the “duty” of international cooperation justified by the General Comment No. 25 relating to existing “international disparities in science and technology”. Although the CESCR does not draw a distinction between duties and responsibilities of international cooperation in that passage, it tautologically identifies the second dimension of the duty of international cooperation with the “resort to international cooperation and assistance”, thereby hinting at its generality. One may therefore consider that what the CESCR refers to there is actually a “responsibility” of States to assist each other and to cooperate in order to contribute to the “development of science and technology” in all States.In order to address the second and third indeterminacies identified in Sections 2.2. and 2.3., our second proposal, when specifying the content of the duties and responsibilities of international cooperation, is to focus on the general positive duty of institution-building mentioned earlier, i.e., the positive duty to institutionalize what the CESCR refers to as the “international scientific and technological community”.While all the manifestations of international cooperation mentioned by the CESCR correspond to what this piece has argued could amount to the content of the duties under or responsibilities for the RPEBSPA, they barely scratch the surface of what is required in terms of international cooperation in order to effectively realize the right in all its facets. Respect for those duties and responsibilities cannot be exhausted in the adoption of “multilateral agreements”, for instance. Rather, and most fundamentally, it includes duties and responsibilities to engage in international institution-building . International institutions are required in particular in order to distribute the burden of international cooperation in the scientific realm more fairly and effectively. This extends, for instance, to the determination of the “adequate” level of access to scientific results across the “international community” which the CESCR rightly advocates, but does not further explicate. Such institutions could also contribute, more generally, to the co-specification of another pivotal albeit underdetermined principle applicable to participation in the universal practice of science, i.e., equality.KA: Writing—original draft. SB: Writing—original draft.


Professor Jens Kossmann was the Specialty Chief Editor of the Plant Biotechnology section at Frontiers in Plant Science from its inception until his death in March 2023 at the age of 59. He ran the section with great enthusiasm and was an important driver of its success. This obituary is designed to celebrate his contribution to plant science as well as his role as a mentor and friend.Jens’ career spanned three countries and many different projects. He studied Agricultural Science as an undergraduate at the University of Göttingen, and later received a master degree in microbiology where he identified his first gene  which leIn his early career he embraced the possibilities that were becoming available due to the emergence of molecular biology. The establishment of plant transformation in the 1980’s had led to the ability to manipulate gene expression in transgenic plants through the use of overexpression and antisense constructs. As plant genome sequences were unavailable at that time, Jens spent much effort identifying DNA that encoded the protein he wished to manipulate. From today’s perspective, it is very easy to underestimate how much work and brainpower was required to isolate a single gene and Jens was a true master in developing new and sophisticated screening methods. He benefited greatly from what he learned in his studies, especially during his master’s project, as he knew that for every question there was a microorganism that offered the answer; it just had to be found. We remember many night-long discussions where the distillation of diverse thoughts about gene identification strategies led to the birth of unconventional ideas for screening which he could never wait to implement. He always looked back at this time with a great fondness and it was probably one of the happiest phases of his career, where he both established himself as a scientist and made many friends with whom he would collaborate for the remainder of his life.His major work involved studying the synthesis and degradation of starch, which is the main carbon store in most plants. In leaves it acts as a short term carbon store and is synthesized during the day and degraded at night, while in storage organs, such as seeds and tubers, it accumulates in much higher amounts and is used for long term storage. Studying starch metabolism is important as it is used as an industrial feedstock, influences plant growth and is the major source of calories in the human diet.In Jens’ early career he was an important international figure involved in isolating genes encoding starch biosynthetic enzymes. He used some of these, encoding isoforms of starch synthase and starch branching enzyme, to demonstrate that they affect starch structure and industrial properties . These dHis most important contribution to science was probably the identification of the glucan, water dikinase enzyme that introduces phosphate groups into starch in many diverse plant species, and which is also involved in starch degradation in both photosynthetic tissue and potato tubers . The inhin vivo, such as a β-amylase (The observation that repression of glucan, water dikinase affects starch degradation led Jens to initiate projects examining this process in more detail in potato as the pathway was poorly understood at the time. He was involved in identifying some of the first enzymes demonstrated to be important in leaf starch degradation -amylase  and a di-amylase . The wor-amylase . He used-amylase . Interes-amylase .Identifying processes that influence the rate of starch synthesis could be used to increase the caloric content of some crops. Jens was involved in many projects designed to identify steps that could influence this, for example the identification of genes encoding proteins which lead to the formation of ADP-glucose - the substrate used to form the starch polymer . AnotherThe institute in South Africa where he spent most of his career had been established prior to his arrival as a link between academia and the local sugar industry. This led to many applied projects aimed at improving sugarcane. These included the development of plants with reduced amounts of starch  as the sAlthough his best known work examined carbon metabolism, he was always interested in developing new projects. When he arrived in South Africa he started using various omics approaches to examine the ways that plant growth promoting substances function . These sThe breadth of his research demonstrated Jens’ fascination with biology. However, he did not just want to understand how genes affected biological processes, but was also driven to try and apply that knowledge to engineer crops with improved yield that can be used to improve human health and alleviate inequality. The most recent Specialty Grand Challenge article  that he JL: Writing – original draft. US: Writing – review & editing.


To determine potential quadriceps versus hamstring tendon autograft differences in neuromuscular function and return to sport (RTS)-success in participants after an anterior cruciate ligament (ACL) reconstruction.n = 25) or the time since reconstruction (n = 25). At the end of the rehabilitation (averagely 8 months post-reconstruction), self-reported knee function (KOOS sum scores), fear of loading the reconstructed knee during a sporting activity (RSI-ACL questionnaire), and fear of movement  were followed by hop and jump tests. Front hops for distance (jumping distance as the outcome) were followed by Drop jumps , and concluded by qualitative ratings of the Balanced front and side hops. Between-group comparisons were undertaken using 95% confidence intervals comparisons, effect sizes were calculated.Case–control study on 25 participants operated on with an arthroscopically assisted, anatomic ipsilateral quadriceps femoris tendon graft and two control groups of 25 participants each, operated on with a semitendinosus tendon or semitendinosus-gracilis (hamstring) tendon graft ACL reconstruction. Participants of the two control groups were propensity score matched to the case group based on sex, age, Tegner activity scale and either the total volume of rehabilitation since reconstruction , and less kinesiophobia . Small and once more non-significant effect sizes point towards lower values in the quadriceps graft groups in the Front hop for distance limb symmetry values in comparison to the two hamstring control groups . The normalised knee joint separation distance were non-significantly and small effect sized higher in the quadriceps than in the hamstring groups .The quadriceps case group  had non-significant and only marginal higher self-reported issues during sporting activities: Cohen’s Only non-significant and marginal between-graft differences in the functional outcomes at the end of the rehabilitation occurred. The selection of either a hamstring or a quadriceps graft type cannot be recommended based on the results. The decision must be undertaken individually.III.The online version contains supplementary material available at 10.1007/s00167-023-07422-y. After an anterior cruciate ligament (ACL) rupture and reconstruction, neuromuscular performance, mostly rated by jump- or hop-performances and movement quality, are predictive for a subsequent second ACL injury , 11, 13.Semitendinosus  and quadriceps femoris tendon grafts show comparable graft survival rates, clinical stability and functional outcomes when compared to each other , 15. In In most studies on this topic, the comparative functional measurements were taken at pre-selected or randomly selected time points. As the duration until rehabilitation completion and return to sports success is highly variable between individuals , a compaTherefore, the purpose of the present study was to compare self-reported and objective functional outcomes, as well as return to sport success, from participants after a quadriceps autograft reconstruction with both a rehabilitation volume-matched and a time-matched hamstring autograft group. We hypothesised that (1) the quadriceps group shows inferior self-report and (2) objective functional values than the hamstring autograft groups and that (3) no between-group differences in return to sport success rates between the groups occurs.This propensity score matched case–control study was conducted as a part of the PReP project . The indThe study was planned and performed in agreement with the Declaration of Helsinki . The study was pre-registered in the German Clinical Trials Register (DRKS), 01. October 2018, DRKS00015313).Individuals with an acute unilateral ACL rupture and having passed an arthroscopically assisted, anatomic ipsilateral quadriceps femoris or a hamstring tendon graft ACL reconstruction were included. Secondary inclusion criteria were (1) being < 36 years of age, (2) have been engaged in any type of sport prior to the ACL injury and (3) aimed to return to their previous sporting activity.Exclusion criteria consisted of a meniscus lesion with a diameter of > 2 cm, (2) a cartilage lesion > ICRS II°, previous musculoskeletal surgery of the uninvolved  leg, leg malalignment > 5°, a multi-ligament injury pattern, severe post-operative complications such as graft failure, arthrofibrosis, or a subsequent second knee injury, acute or chronic inflammation of the musculoskeletal system or muscle soreness and pregnancy.The autograft was selected based on biomechanical and individual criteria. When it was, from the athlete point of view of the participant and/or due to the type of activity, important to preserve the hamstring complex and, thus, to avoid damage to the knee flexor compartment , a quadrTo match two counterpart to each quadriceps graft participant, we screened all 229 participants with a hamstring graft and a measurement at the end of the individual rehabilitation included in the PReP-cohort . A logisn = 25  and, the hamstring graft (control) sample of n = 35  individual participants. N = 10 participants were included in both of the hamstring graft control groups.The quadriceps graft (case) sample consisted of To ensure that they were not only called just once at the hypothetical end of rehabilitation, all participants were prospectively monitored until their individual rehabilitation completion through a series of telephone calls . The preIn the structured telephone interview at inclusion (at 1–3 weeks after the reconstruction), the participants reported socio-demographic and anthropometric details, injury mechanisms , all (rehabilitation) measures taken between injury and reconstruction  and the www.surveymonkey.de.The outcome assessments took place at the individually determined end of the rehabilitation and consisted of a battery of questionnaires, followed by a series of hop and jump tests. Knee function and symptoms were reported using the Knee injury and osteoarthritis outcome score (KOOS) subscales: sport (SPORT), pain (PAIN), symptoms (SYMPTOMS) and activities of all daily living (ADL). The KOOS thresholds/cut-offs for non-restricted ratings (“non-symptomatic”) were: PAIN 89 points, SYMPTOMS 83, ADL 95 and SPORT 72 points . To repoAfter a specific warm-up (jumping jacks and steps), the Front hop for distance (i.e. single leg hop for distance) was performed. The cut-off/threshold for the present case was selected to be an LSI of 90% for the Front hop for distance. The test conduction and measurement quality criteria can be found in the supplemental file 1.The Drop jump screening test followed. A normalised knee separation distance at the jump’s reversal point of 60% was selected as the cut-off threshold for the following ratings and analyses . The detFor the sagittal plane landing quality rating, the Balance front hop test  was perfAll hop/jump tests were performed by self-administration and filmed from a frontal position (3 m distance). The participants used their own smartphone cameras. The videos were expert-rated using the investigator-blinded videos. Participants were educated on how to perform the jumps and hops. In cases of incorrect execution, the tests and, where needed, the instructions for the tests were repeated. This is valid when compared to 3D motion-capture systems for the analyses of sagittal plane knee angles .dz of 0.36; at least 25 full datasets per group are needed to be included in the analyses if a significant result should be found under an 5% alpha and a 20% beta error probability. Thus, 25 participants with a quadriceps graft had to be recruited and 2 × 25 hamstring graft participants from the PReP cohort had to be included for matching purposes.The required sample size was estimated based on the effects for the self-reported sport-associated function (KOOS-SPORT) at a 1-year post-surgery follow-up . The quaThe alpha-error threshold was set at 5% for all inference statistical analyses The analyses were performed with SPSS .d comparisons between groups (quadriceps in comparisons to one of the hamstring groups at each time).Main between-graft comparisons for any interval scaled or pseudo-interval scaled outcomes were undertaken based on the means and 95% confidence intervals comparisons plus between group effect size comparisons. The confidence intervals were displayed separated by groups, while comparisons were undertaken using confidence intervals overlapping comparisons and by Cohen’s 2-tests or the Fisher's exact test, depending on the structure. The groups were compared using relative risks .The numbers (and %) of the participants fulfilling the pre-defined and literature-based cut-offs, again separated by group, were displayed as absolute numbers. Inference-statistically, associations of RTS success and fulfilling the functional cut-offs were checked using ChiExplorative secondary analyses contained linear mixed models for repeated measures. The time effects were modelled as random effects (and factors), the other independent variables (group) and covariates  as fixed effects.No participant was excluded, no one withdrew his/her consent for participation. No adverse events or serious adverse events occurred. All sport-, injury- and surgery-specific characteristics of the study sample can be found in Table The hamstring rehabilitation-matched group showed a significantly shorter time period since reconstruction than the quadriceps graft group . In this period, the total volume of exercise (rehabilitation measures and sport) in minutes was significantly larger in the time-matched hamstring participants than in the quadriceps graft group individuals .Figure The between-graft comparison for the confidence to return to sport (ACL-RSI) and for kinesiophobia revealed no between-graft differences Fig. . Small eIn Fig. Only marginal and non-significant differences between the quadriceps graft participants and either of the two hamstring matching groups occurred in the two balance hopping performances Fig. . The hamOnly 16% in the quadriceps graft group returned to their pre-injury type and level of sport. In the hamstring graft groups, this share was (rehabilitation-matched group) 32% and (time-matched control) 38%). The underlying absolute values for this percentage share and the relative risk including its confidence intervals are, likewise, for all other self-reported and objectively assessed functional outcomes, displayed in the Table None of the outcomes was non-equally distributed between groups with the exception of the Balance front hop for the contralateral leg. Here, more participants of the quadriceps graft group than in the hamstring graft time-matched group had not reached the requested 5 points.The results of the explorative linear mixed models can be found in the Supplemental Table 1. The graft type itself had a significant effect on knee problems during everyday functions; here, the quadriceps patients reported worse values . Furthermore, many co-variates such as age, time since reconstruction, having been rehabilitated during the COVID-associated restrictions, and the Tegner activity scale had a significant effect on the outcomes. In contrast, only minor non-significant interaction effects (co-variate*graft type) occurred: graft type* sex had a negative impact on kinesiophobia, whereas graft type*lockdown led to a decrease in both kinesiophobia and in the Front hop for distance limb symmetry index, likewise. Graft type*age significantly increased the normalised knee separation distance at landing.The most important finding of the present study was the marginal differences in self-reported and objectively assessed function between participants with a quadriceps autograft reconstruction and those with hamstring autograft reconstructions. These marginal differences were independent of whether the hamstring control group was matched to the quadriceps graft case group in terms of rehabilitation amounts or in terms of time since reconstruction. Therefore, the hypotheses (1) and (2) must be rejected, while hypothesis (3) could be verified.The participants completed their individual rehabilitation averagely at 8 months post-reconstruction. This value corresponds to reference studies in which the return to sport clearance in young, non-professional athletes was reached at 8.2 months post-surgery . Thus, eThe non-significant and, according to the effects sizes, marginal differences between the quadriceps and hamstring-tendon grafts are in accordance with the current literature in the field , 22. NeiSport-associated self-reported outcomes scores were, additionally, only slightly superior in the hamstring-graft groups, whereas the kinesiophobia values tended to be lower in the quadriceps group. An explanation for the latter finding may be found in the explorative analyses; the graft types may have acted differently during a lockdown in terms of kinesiophobia . A smallIn general, upon individual rehabilitation completion, those participants with a rehabilitation-matched and those with a time-matched hamstring graft volume were not different than participants with a quadriceps tendon graft.As only marginal between-graft differences in functional outcomes at the end of the rehabilitation occurred, the decision to selection of a hamstring or a quadriceps graft type cannot be undertaken based on the results. Beyond comparable functional findings of other studies, this conclusion is supported by findings of no differences in stability outcomes and in the odds for a Lachman test grade 0 differences between grafts at an early post-reconstruction time point , 22. In As only considerably low shares of the participants fulfilled all the functional cut-offs for a successful function at the end of their formal rehabilitation, the end of the rehabilitation is, thus, not the actual end of the rehabilitation . One mayFuture studies are warranted to determine potential differences in the trainability between the different graft types, both during rehabilitation itself at the early and late-stage, and during subsequent recurrence-preventive measures. A graft comparison in other samples such as adolescents or in older participants than ours would furthermore expand the transferability of the results.From a pragmatic point of view and due to the research gap sketched above (the need for a rehabilitation- versus time-matching), a randomised controlled approach could not be adopted in the present study. Although meta-analyses found no significant differences in the effect estimates between the randomised controlled trials and observational studies , it stilIn this study, only tests that were self-administered by the patient in view of the pandemic situation and the otherwise higher dropout rate were adopted; this approach was assumed to be the most practicable way. However, this setting may display a more vulnerable validity than laboratory measurements.Although a state-of-the-art effect estimator was used, the LSI may overestimate one’s functional ability by masking bilateral deficits . RecentlBy including 3 × 25 participants, the sample size calculation was followed; the analyses are, thus, considered as adequately powered. However, a larger sample size would have led to even more robust findings, although the clinical relevance of the  still would question the clinical relevance of the between-graft differences.Only marginal and non-significant differences in functional outcomes between quadriceps and hamstring autograft reconstructions occur after anterior cruciate ligament ruptures at the end of rehabilitation. The decision for selecting a hamstring tendon or a quadriceps tendon autograft cannot conclusively be recommended based on these functional outcomes but must be undertaken individually.Supplementary file1 (DOCX 96 kb)Below is the link to the electronic supplementary material.


To evaluate the safety and the effectiveness of our novel penetrating keratoplasty for infectious keratitis.Retrospective, noncomparative, interventional case series of patients with infectious keratitis who received the novel penetrating keratoplasty technique were analyzed. A prepared plastic sheet was located between the diseased cornea and iris-lens diaphragm. After the diseased lesions were removed, the graft was positioned on the plastic sheet and sutured to the recipient bed. The plastic sheet was pulled out from the anterior chamber before the all interrupted sutures were placed. The intra- and post-operative complications, the outcome of the graft and the number of corneal endothelial cells were analyzed.A total of 82 eyes of 82 patients was included. The mean follow-up period was 29 ± 16 months (range from 13 to 45 months). No intraocular content extrusion, simultaneous cataract extraction and suprachoroidal hemorrhage occurred. Direct contact between the infectious cornea and the graft was successfully avoided. Greater than expected endothelial cell reduction or complications were not found.This modified technique effectively prevents the extrusion of intraocular contents while avoiding the direct contact with donor endothelium during the procedure. The occurrence rate of complications such as endothelial cell loss is not higher than the conventional methods. Suprachoroidal hemorrhage is one of the most devasting intraoperative complications. It occurs more frequently than might be appreciated in corneal transplant, ranging from 0.45 ~ 1.08%. It’s incOther contributing factors include previous surgery, diabetes, hypertension, older age, anticoagulant therapy and vitreous loss. The rupture of long or short posterior ciliary artery is liable to occur while the intraocular pressure drops rapidly in a short time. The best preventive measures are the control of blood pressure and tachycardia, and especially to avoid the sudden release of aqueous humor during the surgery.Various modifications have been reported to prevent the forward movement effectively by supplying counterbalance against the extrusion. The most common precautionary measures are to place the graft on the diseased cornea and suture the donor to the recipient bed, then followed by removing the diseased cornea before the rest interrupted sutures was placed –5. It isThis retrospective, noncomparative, interventional case series was performed between March, 2017 to March, 2020. It was approved by the Institutional Ethics Committee of Chengdu Aidi Eye Hospital, and performed in compliance with the Declaration of Helsinki. Informed written consent was obtained from all patients. For fungal keratitis, 1% voriconazole and 5% natamycin were used topically, and oral itraconazole  was given if required. For bacterial keratitis, 0.5% Levofloxacin and 0.3% tobramycin were used. Patients who were suitable for deep anterior lamellar keratoplasty or had a lesion extended to the corneoscleral limbus were excluded. Patients with follow-up less than six months were also excluded in the analysis.All surgeries were conducted with the modification by four skilled surgeons  under retrobulbar block or general anesthesia. A plastic sheet, approximately 5.0 × 9.0 mm in size (based on the diameter of the trephination) Fig. , A, was After the partial thickness trephination, two paracentesis were created at the 6- and 12-o’ clock positions, and the full-thickness arc wounds from 4 to 8- and 10-2-o’ clock positions were completed symmetrically. The width of arc wound was based on the size of the plastic sheet. After completing the lamellar demarcation of the recipient bed with trephination, the full-thickness incision of the vertical or horizontal diameter of the recipient bed with its arc length of about 6.75 mm was made, the anterior chamber was injected with antibiotic solution to wash the inflammatory exudates . Then the sufficient viscoelastic agent was injected into the anterior chamber (AC) and the adhesion between the cornea and the lens–iris diaphragm was separated. One end of the plastic sheet was inserted into the anterior chamber via the superior incision, and the other end was pulled out from the inferior incision with curved toothed forceps, just between the infectious cornea and the iris–lens diaphragm. The sheet was then sutured symmetrically to the recipient bed and fixed with four 10 − 0 nylon sutures. Both ends of the plastic sheet were sutured radially in the stromal layer of the recipient margin, and then the donor cornea was sutured in alignment with the recipient bed with 2–4 stitches. Care must be taken not to tying the first two sutures too tightly to avoid pushing the sheet to the donor endothelium and the increased abrasion. The plastic sheet that was placed between the diseased cornea and the lens-iris diaphragm, like a corneal transplant, was sutured in the anterior stromal layer of the recipient bed in radial pattern. Detailed steps of the technique were shown in Fig. The ulcerated cornea was excised completely. The exudate membranes, as well as the hypopyon over the iris and pupil, were mechanically removed by the “indirect” force of the viscoelastic agent and forceps. After wash with antibiotics in AC, the viscoelastic-coated donor button with its endothelium down was overlaid on the plastic sheet and fixed at the 3 and 9 o’clock positions with four sutures. All 4 tying knots on the sheet were removed, and the sheet was carefully pulled out from AC Fig. . The othTopical or/and systemic treatment are used to decrease the risk of recurrence of initial microbial infections, retro-donor membrane formation, glaucoma and immunological graft rejection postoperatively. The drug delivery method depended on the condition of the operated eye based on previous literatures or expert consensus –12. The 82 eyes from 82 patients  with refractory infectious keratitis underwent penetrating keratoplasty using our method. The mean follow-up period was 29 ± 16 months . The mean age was 51 ± 12 years . 61 cases were infected with fungi and 21 cases were infected with bacteria. 19 cases had corneal perforation and adherent leukoma to iris. Hypopyon was found in 24 cases. Anterior synechia or adherent leukoma was found in 15 cases, and pupil exudative membrane was found in 14 cases. Cataract was found in seven cases. The interval time between PK (penetrating keratoplasty) and infection was 2–7 weeks.The mean diameter of the graft was 6.75 mm . Each procedure was completed without severe intraoperative complications, such as suprachoroidal hemorrhage, vitreous prolapse, lens extrusion, suture placement challenges, and iris–lens damage.There was no recurrence of infectious keratitis. The anti-fungal and anti-bacterial drugs were used for 6 weeks and 3 weeks, respectively. Anatomical integrity was achieved in all eyes. No cases had choroidal and retinal detachment. Shallow anterior chamber was observed in 6 eyes (7.6%). Among these, there were 3 cases with posterior synechia, and another 3 cases with cataract development. Secondary glaucoma was confirmed in 14 eyes (17%), which was mostly caused by inflammation, but cured by topical anti-glaucoma medications.2 to 1978 ± 225 cells/mm2 at 1 month (loss of 19%) and 1829 ± 144 cells/mm2 at 3 months (loss of 25%).Four eyes (6%) developed postoperative cataracts with variable degrees of severity. Graft rejection occurred in 13 eyes (17%) and the neovascularization was found in 6 eyes, but the rest grafts were still clear. The mean postoperative endothelial cell densities decreased from 2439 ± 138 cells/mmDuring PK procedure, the most devasting complication is expulsive suprachoroidal hemorrhage. If it occurs during the open-sky step of the surgery, it typically leads to the expulsion of intraocular contents. Its occurrence in related to old age, hypertension, high myopia, tachycardia during operation, the presence of anterior chamber IOL, previous hemorrhage in the same eye and Valsalva maneuver, et al.  Sudden decompression could raise episcleral venous pressure. Long-term hypotony provides more opportunity for scleral collapse and translocation of intraocular structure including iris-lens diaphragm, vitreous or retina.The conventional steps for reducing these contribution factors include the Flieringa ring, local or general anesthesia and ocular massage combined with intravenous administration of mannitol. Although the different types of anesthesia combined with scleral fixation ring are thought to be safe enough in vast majority of cases, still these can be a potential threat to safety of operation, especially when coughing or bucking related with imperfect general anesthesia or raised orbital pressure to venous outflow associated with retrobulbar anesthesia. The challenge of completely eliminating extrusion of intraocular contents remains unresolved for the lack of counterbalance.Different modifications have been adopted previously. These improvements had been changed from suturing the graft on the full-thickness diseased cornea to suturing the graft on the anterior lamellar bed –5. The aOur approach worked as an enhancement of the previous techniques. The plastic sheet which acted as a “temporary tamponade”, was fixed with 4 sutures, it can resist the extrusion of intraocular contents by alone or combined with the graft. When hypopyon and inflammatory exudation in anterior chamber are eliminated, the donor then was sutured to the recipient bed. Here, the plastic sheet plays the role of a “transitional lenticule”.No infection recurred in all cases postoperatively. The incidence of postoperative cataract (6%) and secondary glaucoma (17%) is not higher than that of previous report , 19. TheA delicate manoeuvre is required during insertion of plastic sheet beneath the ulcerated cornea especially when the diseased cornea adhered with iris. Rough handling may lead to iridodialysis, anterior lens capsule or Zinn’s ligament injury. When the superior and inferior incisions are made, a gently curved, blunt-tipped 26-gauge cannula on a 5ml antibiotics-filled syringe is inserted into the anterior chamber to separate the adhesion. Make sure the tip must always be upward and pressed against the endothelial surface and make a slow Z-shaped movement. When the adhesions are relieved, a curved toothed forceps is inserted from inferior incision to superior one, the plastic sheet is pulled out and sutured. Usually, hypopyon and exudate can be pushed away by injection of viscoelastic from the two sides of the plastic sheet, the thick pus or proliferative membrane covering the pupil can be taken out with curved toothless forceps / toothed forceps, an oval hole preformed in the center of the film will facilitate the removing of infectious substances in pupil area and it will not weaken the effect of the sheet to prevent extrusion of the intraocular contents. To prevent damage to donor endothelial cells, several steps would be required: first, adequate viscoelastic agent is injected between the endothelium of the graft and the sheet. The sheet is thinner and smoother than the ulcerated cornea, which has less resistance on the endothelium of donor when removed from under the implant. For the reason of convex shape, the gap between the corneal endothelium and the plastic sheet could lessen the abrasion of the endothelium while the donor is sutured directly above the flat plastic sheet. Next, care must be taken not to tying the first two stitches too tightly as normal to avoid pushing the sheet to the donor and increased abrasion of donor endothelium when removing the sheet. Finally, the plastic sheet (Fig. In our cases, no serious complications associated with intraocular extrusion occurred, but it is well known that the final outcome may depend on the check-up and medication. There are still some limitations for our method. For example, the follow-up period is not long. Some patients may be lost during follow-up. Occasionally, very few patients may receive enucleation in another hospital due to recurrent infection or refractory glaucoma, and it will be difficult to know the long-term efficacy of the procedure and may affect the overall surgical outcomes. It is necessary to strengthen communication with the patient and improve their good compliance.The plastic sheet was easily prepared with no special equipment was required. This innovative technique based on this effective, easily constructed plastic sheet facilitated the proper positioning of the anterior segment during PK for infectious keratitis patients.