Extended end-plate (EP) bolted connections are widely used in steel structures as moment-resisting connections. Most of these connections are semi-rigid or in other words flexible. The paper aims to study the behavior of such connections under the effect of column top-side cyclic loading using the finite element (FE) method. For semi-rigid connections, it is very vital to determine the moment-rotation relationship as well as the connection stiffness. These beam-column connections have been parametrically studied, the effect of joint type, shear forces, diameter of bolt, thickness of end-plate, and end-plate style were studied. Parametric studies show that the panel zone shear force is the key factor and has a significant effect on the connection stiffness. Finally, based on the component method, the stiffness of the bending component is improved, and the initial stiffness calculation model of the connection under column top-side cyclic loadings is established. The results show that the calculation model is in good agreement with the finite element analyses, and this proves that the calculation model proposed in this study could act as a reference method. M-θ) relationship curve of the joint as the design basis.Both the 1994 Northridge earthquake and the 1995 Hyogoken-Nanbu earthquake ,3,4,5 reKrishnamurthy, N. et al.  used fleSherbourne  and GangThe moment-rotation behavior of the end-plate joint with an extended stiffener was investigated by Tartaglia et al. , and alsMost of the above studies conform to the “strong column and weak beam” design criteria. The test, finite element, or both, simulations are carried out under the condition of beam tip loading. However, in actual engineering, for example, considering the combined effect of the floor slab and beam, the stub effect is caused by opening windows in the filling wall, and so on ,30. ThesTo further study the mechanical behaviors of the extended end-plate under the column top-side loading, this paper includes three main phases. The first phase is based on our previous experimental research  using thpreF) of the two kinds of bolts is 155 kN and 225 kN. The beams and columns of the six test specimens all adopt hot-rolled I-shaped sections, the steel strength grade of all components of the joint is Q345B, and the basic configuration of the joints are shown in Fc = 0.3 × fc × Ac = 1250 kN, where fc takes the nominal yield strength of Q345B steel 345 Mpa, and Ac is the column section area. The test data of the material properties of the joint components and the bolts have been used as the parameter values of the FE material model in In the experiment, six joint specimens of extended end-plate connections were designed, namely, the intermediate column joints (IC-EP1/2/3) and the edge column joint (EC-EP1/2/3), respectively. These joints were designed according to the standard for the design of steel structure , and theThe test setup is shown in The moment-rotation responses for all specimens are illustrated in ® [The extended end-plate connection analysis model was established using Abaqus Standard®  module. The stress-strain relationship of the steel can be the simplified trilinear model and considers the plastic hardening of the material. The Von Mises yield criterion is adopted to determine whether the steel reaches the yield point in the multi-axial stress state. When the equivalent stress of the steel exceeds the yield stress, the steel will undergo plastic deformation. A bilinear kinematic hardening model was applied to the high-strength bolt constitutive, which is very suitable for high-strength steel. The material parameters of the FE model correspond to every actual tensile coupon test result to better verify the mechanical properties of the joint. Poisson’s ratio was assumed to be 0.3. See All parts were modeled using the 8-node linear brick incompatible mode element (C3D8R), which reduced integration and used hourglass control. The model is divided into five parts, namely, beams, columns, end-plates, bolts, and web stiffeners. Tie contact was used for the welding relationship between the end-plates and steel beam and does not consider other weld modeling. The general mesh size for the entire model was moderate mesh density, and there were at least three layers in the thickness direction. All components were controlled by a structured mesh. The above-mentioned IC joint of the full model , the half-model (FE 1/2), and the quarter-model (FE 1/4) corresponding the total number of elements is about 104,000, 52,000, and 26,000 elements, respectively, and normal hard contact to simulate the extrusion phenomenon between bolts and plate. Tangential penalty function was used to simulate friction between the end-plate and the column flange (the friction coefficient of 0.44). The shapes and mesh division diagrams of the components are shown in Considering the symmetry boundary conditions and the loading direction, to divide an appropriate element mesh, the accuracy of the finite element analysis result can be guaranteed. Due to the difference of boundary conditions, the IC joint adopts half-model (FE 1/2) and quarter-model (FE 1/4), and the EC joint only adopts half-model (FE 1/2) for simulation calculation. The above symmetrical models combined themselves into a full-model , for specific values refer to In order to simulate the loading effect and boundary constraint of the beam tip and the column top-side, coupling constraints are applied to the specified area to eliminate unrealistic stress and strain concentration. Each model applies three types of loads, the first was the constant load that was applied at the middle of the bolt shank to simulate the bolt pretension force, the second is to maintain an axial compression ratio of 0.3 and apply a constant pressure value on the column-top, while the third was the cyclic load that the displacement was applied in the form of small steps at the column top-side to generate the moment on the connection. The cyclic displacement history of FE is similar to the experimental loading protocol for increasing amplitude, and both were incrementally imposed.These FE models were established and solved by using Abaqus software . As shown in As presented in M-θ) skeleton curve. The M-θ skeleton curves attained by numerical calculations in comparison with the moment-rotation skeleton curves obtained from the tests. The results show that there was good agreement between the test results and the FE simulation in the elastic stage. Additionally, in the stage after yielding, there was some disparity due to the simplification of the material constitutive behavior of the materials and test errors.As shown in Based on the above finite element verification and experimental research, a parameter study was conducted to develop three-dimensional FE models with variable parameters to simulate the IC joints and EC joints of the extended end-plates connection. Both material and geometry nonlinearities were considered in the analysis. This study aims to understand the connection behavior of such joints under cyclic loading on the column top-side and to determine the valid parameters on ultimate moment, rotation capacity and initial rotational stiffness.A total number of 144 3D-FE models were created for the connection of the extended end-plate beam to column joints to study their behavior under cyclic loading. These models and the investigated parameters are summarized in As shown in maxM) of the joint is always less than the plastic flexural resistance (bpM) of the beam or column. Therefore, the plastic hinge did not occur in the beam section, and the column section is not buckled. Failure always occurs in the connection component or panel zone.The FE analysis shows the different typical failure modes in The column top-side loading method is extremely sensitive to the shear effect of the panel zone, and the shear deformation of IC joints is more obvious than that of EC joints. Adopting different beam lengths to change the moments of the connections affects the shear force in the panel zone. The effect of end-plate thickness on the moment-rotation curve of the connection is shown in The influence of the bolt diameter on the ultimate flexural resistance of the connection is shown in Comparing the end-plates S1 and S2, the difference is the distance between each row of bolt holes and the end-plate size. The influence on the initial rotational stiffness of the joints is shown in By referring to ②,③). Then, as the load reverses, another opening between the end-plate and the column flange begins to appear at the beam web (④). By further load reversal, the tension is transferred to the upper beam flange, and the opening appears between the end-plate and the beam upper flange, when the tension increased in the upper flange and compression increased in the lower flange , the opening between the lower beam flange and the column flange begins to close (⑦).The difference between the IC joint and EC joint is whether to set up a single-sided connection or double-sided connection in the column flange, which results in the shear of the IC joint panel zone being twice the EC joint. At the ultimate loading capacity, the shear rotation of the IC joint and EC joint account for approximately 66% and 25% of the total rotation, respectively. Extracting the hysteresis curve from the cyclic load FE model shows that the characteristics of the IC joint are plumper, and their rotation span is slightly larger than the EC joint.The size information of the 019-ICBC1D20t16L15S1 model (test specimen IC-EP1) and the 091-ECBC1D20t16L15S1 model (test specimen EC-EP1) are the same, the IC joint can enhance the joint stiffness remarkably compared to the EC joint, but the ultimate flexural resistance is basically the same. The above reason is that the strength is controlled by the failure of the weakest component. The two joint size’s information is the same, and the weakest part is also unanimous, so the strength difference is slight; while the stiffness is determined by the stiffness contribution of each component. The panel zone boundary conditions of the IC joint are significantly different from the EC joint. The component stiffness of the IC joint panel zone is much greater than that of the EC joints. Under the column top-side loading method, the stiffness of the panel zone has a significant effect on the stiffness of the entire joint, so the stiffness of the two types of joints is obviously different.epb), the column flange in bending (② cfb), and the bolt in tension (③ bt). Then, the column web part is composed of five springs, which simulate the shear (⑥ cws), tension (④ cwt) and compression deformation (⑦ cwc) of the column web, stiffener in tension (⑤ st) and in compression deformation (⑧ sc), respectively. The deformation of the entire joint is composed of these two parts, and the initial rotational stiffness of the connection can be expressed as:conK and cwK are the stiffness of the connection and column web, respectively.The initial stiffness of the extended end-plate connection joint can be predicted according to the classical component method recommended by EC3 . MeanwhiF/2 at the center can be expressed as mω = αFab/2D, where mω is the center deflection of the plate, α is the coefficient related to the length and constraints of the plate, D is the bending stiffness of the plate per unit width, 3/12(1 − μ2)D = Et. For a rectangular cantilever plate with one fixed side and three free sides, the α coefficient reference [epb1ω = epb1F/2k, where epb1k = epb11/δ = D/(αab) = 1.79 × ep3/((1 − μ2)ab)Et, ept is the thickness of the end-plate; and the T-stub of No. II plate boundary conditions and bending stiffness are equivalent to No. I plate.For the calculation of the bending stiffness of the column flange and the end-plate, the deflection at the bolt hole of the rectangular plate is used to obtain the component stiffness. As displayed in eference  is 0.046The bending stiffness of the end-plate is:E is the elastic modulus of steel, μ is the Poisson’s ratio of the material; cft and ept are the thickness of the column flange and end-plate respectively; cfa, epa and cfb, epb are the calculated length and calculated height of the rectangular plate in the end-plate and column web, respectively.The bending stiffness of the column flange is:sA is the effective area of the bolt, generally 80% of the nominal area of the bolt shank; bL is the calculated length of the bolt, bL = ep + tcft + 2wh + (tht + n)/t2, refer to ept is the thickness of the end-plate, cft is the thickness of the column web, wht is the thickness of the bolt washer, and ht and nt are the thickness of the bolt head and nut, respectively.For high-strength bolts, the pretension of the bolts significantly improves the initial stiffness of the connection. The coefficient γ is introduced in consideration of the effect of its pretension. Its value is referred to in , and genθ can be expressed as:Integrate the stiffness of the connection joint of the extended end-plate, according to the beam end rotation conforms to the plane-section assumption and the superposition principle of displacement in the elastic stage, the rotation angle According to the physical meaning of the initial rotational stiffness of the joint, the stiffness of the connection part of the extend end-plate is:M is the elastic ultimate moments at the connection, conk is the connection stiffness, epbk, cfbk, and btk are the bending stiffness of the end-plate, column web, and the tensile stiffness of the bolt, respectively.In the formula, According to the finite element analysis in the above section, it can be seen that the direction of force transmission, the axial force transmitted from the connection, causes the column web to be in a real state of compression and tension. The method of simplifying the column web to axial compression and axial tension plate can be used to calculate. Meanwhile, the influence of different load forms on the joint stiffness must also be considered. To calculate the initial rotational stiffness of the IC joints under the antisymmetric load and the EC joints under the asymmetric load.cwh is the calculated height of the column web b; if the column is a welded steel section, eff,c = tbf + 2he,ep + 2tep + 2b, where e,eph and e,ch are the effective heights of the weld of the end-plate and column web, cr is the root radius of the column flange weld, bft is the thickness of the beam flange, and the φ value is 0.5.The expression of the compression stiffness of the column web of the IC joint and EC joint is:lumn web a; tcw iseference , if the The formula for calculating the tensile stiffness of the IC joint and EC joint is shown in Equations (8) and (9).λ is to consider the influence coefficient of the bolt hole spacing, and the value 3λ = (p/w); and eff,tb is the effective tensile width of the column web. The calculation diagram is shown in cm is less than (p − m)/2d, then eff,tb is c + dm2m; when cm is greater than or equal to (p − m)/2d, then eff,tb is cmtan45° m + p)/2+ tcf2r, and G is the shear modulus of steel.To calculate the deformation The shear stiffness of the web of the IC joint and EC joint is:In the formula, when the connection belongs to the EC type, the column web is sheared on one side, and the β coefficient in the equation is 1; when the connection belongs to the IC joint type, the moments on both sides of the panel zone are equal and in the same direction, so the β coefficient in the equation is 2 if the moments on both sides of the panel zone are equal and in the opposite direction, so the β coefficient in the equation is 0, the bending moments offset each other, that is, no shear force. This paper does not involve such joints.The stiffeners of the column webs also adopted the similar axial tension and compression method at the column webs to calculate the stiffness. As shown in Tensile stiffness of column web stiffener:st is the thickness of the stiffener of the column web; eff,stb and eff,scb are the effective widths of the stiffener under tension and compression, respectively. Considering that the bolt force diffuses at 45° under tension.Compression stiffness of column web stiffener:eff,stb = cmin{m + me,d + 2m,e + m + m/2,mcd + m/2,bs}m + d, where cm is the distance from the center of the bolt hole to the welding foot of the root of the column web, e is the horizontal distance from the center of the bolt hole to the external edge, m is the distance from the bolt hole to the surface of the beam flange, dm = 1.5 × bd, bd is the nominal diameter of the bolt; effective width of stiffener under compression eff,scb: if ep(w – bf)/2 ≥ tepw, then eff,scb = bf/2min{w + cft + ep,wbf/2}t, if ep(w – bf)/2w<ept, then eff,scb = ep/2min{w + cf,bcf/2}t. epw, bfw, and cfw are the width of the connecting end-plate, the width of the beam flange, and the width of the column flange, respectively; sb is the width of the stiffener and ept is the thickness of the end-plate. The above specific parameters are shown in Compression considers the pressure transmission in the direction of 45° along with the thickness of the end-plate and column flange at the lower flange of the beam. Effective width of stiffener under tension: M, the five deformations of the column web are:The shear, tension, and compression deformation of the column web and the tension and compression deformation of the stiffeners cause relative deformation between the panel zones, which in turn causes the beam ends to rotate. Under the action of the moment The rotation produced by the column web is:The overall stiffness of the column web is:h0 is the vertical distance between the center of the upper and lower flanges of the beam, h0 = bh – bft, bh is the height of the beam, and bft is the thickness of the beam flange.In the formula, First applied to the test specimens IC-EP1/2/3 and EC-EP1/2/3, to verify the improved component model for predicting the initial rotational stiffness, Δ represents the ratio of the difference between the two to FE, that is Δ = T − KFE|/KFE|K. For the average of this ratio, the relative difference between the two is 8.99%. For dispersion, the standard deviation of this relative difference is equal to 6.88%. Due to the complexity and high cost of the test, the value calculated by the component method is still acceptable. The above two groups of verification data verify the validity of the initial rotational stiffness’s theoretical calculation. So generally, the theoretical equation proposed in this article is of good applicability for most reasonably designed joints.To further validate the above-mentioned component model. The stiffness of the 144 finite element models of the above parameter analysis has been calculated. The model included parameters such as different column section sizes, end-plate thickness, bolt diameter, and end-plate size to verify the proposed component method. According to the influence of different parameters on the mechanical behavior of the extended end-plate connection, the parametric FE models were established, and the effects on the flexural capacity, rotational stiffness and limit rotation of the joints are studied. Meanwhile, the joint typical failure model is divided into six types. It is also found that the joints also show nonlinear characteristics in the early stage, and some connected components have already yielded in the initial stage, and each component will not respond uniformly as a whole. The behavior of joints in the whole process is nonlinear.In most studies in the past, the main focus has been on the study of the moment-rotation relationship of the connection under the beam tip loading method, but this article focuses on some force forms in actual engineering, using the column top-side loading method to study the parameter’s comprehensive impact on joint performance. Additionally, the research on the panel zone shearing effect is focused, and it is concluded that the value of shearing force acting on the connection has a great influence on the mechanical behaviors of joints in this type of loading. Meanwhile, the shear rotation of the IC joint parameter model accounts for about 2/3 of the total connection rotation times, and the shear force in the panel zone is twice that of the EC joint. However, under the control of the failure mode of the weakest component, the ultimate flexural resistance capacity of the IC joint and EC joint remains consistent.Increasing the diameter of bolts or the thickness of the end-plate in most cases enhances the behavior of the connection, in other words, increases both moment capacity and rotation capacity by a certain percentage. However, the yield rotation of the connection is decreased with an increase in the thickness of end-plates, resulting in low connection ductility. In spite of this, the use of medium-thickness end-plates with bolts of appropriate diameters can greatly improve the overall mechanical properties of joints.According to the mechanical behavior of the joint components. The component model of the joint under the column top-side loading method is proposed, and the initial stiffness expression is established. The bending stiffness of the component was improved by adopting the large deflection calculation of the plate and shell theory, and considering the significant difference in the contribution of the shear stiffness component of the panel zone between the IC joint and EC joint. The expression is verified by experimental results and the 144-parameter FE model, which proves the reliability of the initial stiffness expression.This study involved analyzing the performance difference between IC joints and EC joints of extended end-plate connection under the column top-side loading method. Firstly, based on the test data of six joints, a set of symmetrical models was developed to verify actual experimental results, and the failure modes and joint stiffness were analyzed and compared. The above work laid the foundation for parameter analysis; a total of 144 symmetrical 3D finite element models were created to study the influence of cyclic loads on the extended end plate beam-column connection with different parameters. Finally, a calculation equation for the initial rotation stiffness of the joints was presented based on the component method. The key conclusions of the study include the following:


Medically-focused journal clubs have been used as an educational tool for over 100 years, with research indicating that they improve knowledge, reading behaviour, and critical appraisal skills. However, it is unknown how widespread they are in Australian medical schools, nor the opinions of medical education leaders as to their value.A nationwide cross-sectional study was performed among academic leaders from every Australian medical school. Individuals were asked to complete a survey detailing their attitudes towards journal clubs using single- or multiple-answer questions, Likert scales, and ranked data. They were asked whether students at their institutions were able to partake in journal clubs, and if so, provided details on their implementation.At least 1 response was collected from 18 of 19 Australian medical schools. The response rate was 40.8% (60 of 147), and 36 responses (60.0%) were from heads of clinical schools. Respondents from 15 of 18 institutions (83.3%) stated that their institution had a journal club. Of these, 23 (65.7%) were metropolitan institutions and 12 (34.3%) were rural institutions. Eighteen (51.4%) journal clubs were clinician-led, 13 (37.1%) were run through specific hospital departments, and 23 (65.7%) occurred during clinical years. Most respondents (20 [57.1%]) stated that the primary aim of the journal club was to develop critical appraisal skills.Journal clubs are a highly regarded educational tool in the armoury of medical school educators, with significant heterogeneity in their structure, geographic prevalence, and intended purpose. Further studies of their efficacy in teaching evidence-based medicine is warranted. In Australia, the last 2 decades have seen a profound shift in the curriculum and pedagogy of medical education, with less emphasis on traditional lecture-based learning and more emphasis on teaching that can be applied and practiced, such as problem-based learning, simulation, and inter-professional teamwork . The movApproval for this study was obtained from the University of Melbourne Department of Medical Education Human Ethics Advisory Group (Ethics ID: 1648448.1).All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation  and with the Helsinki Declaration of 1964 and its later amendments. Informed consent was obtained from all survey respondents included in the study and a plain-language statement was provided. This study was designed to improve quality in medical education through expert opinion in the form of a survey. Participants were made aware of the study and no staff—excluding the authors listed—had access to the data. Confidentiality was maintained at all times. The study did not involve any identifying data that could breach privacy. Respondents completed the survey on a voluntary basis, after which the results were pooled and analysed.A cross-sectional survey research design was used.www.surveymonkey.com/). The complete survey is available as We conducted a survey of key academics at all Australian medical schools to identify whether (1) their school had a journal club, (2) how the journal club was implemented if there was one, and (3) what they personally thought of journal clubs as an educational tool. The survey was administered online using the survey tool provided by Survey Monkey . If the necessary information could not be gleaned from online searches, the university was contacted directly.Included in our survey were all Australian medical schools that contained a cohort of students at every year level. This resulted in the exclusion of 2 newly established medical schools. All clinical schools based in Australia were included in the study, with the exception of schools consisting solely of a rural general practice clinic.A 10-point survey was developed to gain information on the participants’ roles within the university, preferred journal club logistics, attitudes towards journal clubs, and whether or not opportunities were available for medical students to partake in them. If a participant indicated that they were aware of a journal club’s existence at their institution, we asked 7 more questions pertaining to its implementation. For the purposes of our study we defined a journal club as “a group of people, including medical students, who meet periodically to discuss research articles in the scientific or medical field. Discussion may include, but is not limited to clinical application, biostatistics, epidemiology, and critical evaluation.” The survey, along with a plain-language statement, was initially delivered online via email, with 2 reminders. If no response was received electronically, the survey was delivered through standard mail. Responses were collected and securely stored on an Excel spreadsheet used for qualitative analysis.The respondents were dichotomised according to the Australian Standard Geographical Classification–Remoteness Area . The claResponses were collected using single- or multiple-answer questions, 10-point Likert scales, and ranked data.A ranking average was used to determine the intended purpose of journal clubs in medical education. The ranking average was determined as follows: w=weight of ranked position and x=response count for answer choice {(x1w1+x2w2 ... xnwn)÷}. The primary intended purpose of journal clubs, which respondents ranked as the most important, had the largest weight. The lowest-rated intended purpose (ranked in the last position) had a weight of 1. The criteria with the highest average score were deemed the primary purpose of journal clubs.One or more responses were collected from 18 of the 19 Australian medical schools (94.7%). This corresponded to a total of 60 of 147 (40.8%) responses, and most respondents (36 [60%]) were clinical school heads. Deputy heads of medical schools and academic leaders each comprised 7 (11.7%) responses, while heads of medical schools accounted for 6 (10.0%), and deputy head of clinical schools made up 4 (6.7%). Of the 60 collected responses, 35 (58.3%) were educators based in metropolitan centres, with the remaining 25 (41.7%) based in rural centres.Students’ ability to critically evaluate evidence was rated of great importance by these academics , as was an appreciation of research methods , and an understanding of biostatistics and epidemiology .Generally speaking, journal clubs were highly regarded for the education of medical students  and were thought to be effective at teaching research skills .When asked to rank the purpose of a journal club on a scale from 1 to 6 (with 1 indicating the highest importance) as demonstrated in Twenty-one (35.0%) respondents felt that journal clubs were of such importance that attendance should be made compulsory. However, 20 (33.3%) felt that journal club attendance should not be mandatory, while 19 (31.7%) were unsure.The plurality of respondents (25 [41.7%]) thought that journal clubs should only be run during the clinical years, 25 (41.7%). This was followed closely by the opinion that they should be run throughout medical school (23 [38.3%]), and less popular options were that journal clubs should be held during a compulsory research term (5 [8.3%]) and during the final year only (5 [8.3%]). Two responders (3.3%) felt that journal clubs should never be implemented during medical school.There was a high prevalence of journal clubs among medical schools, with 15 of 18 universities (83.3%) stating that they incorporated a journal club in their curriculum. Of the 60 respondents to the survey, 35 (58.3%) stated that their clinical school or institution had a journal club, and they were asked a further series of questions. Twenty-three (65.7%) of these respondents were based at metropolitan sites, while the remaining 12 (34.3%) were rurally based. Only 48.0% (12 of 25) of rurally based institutions had a journal club, compared to 65.7% (23 of 35) of institutions at metropolitan sites.As seen in Journal clubs were most commonly conducted during the clinical school years (23 [65.7%]), with fewer being available throughout medical school (4 [11.4%]), the pre-clinical years (4 [11.4%]), and the final year (4 [11.4%]). Two respondents (5.7%) stated that the journal club was held during a compulsory research term, and 2 (5.7%) were unsure when their journal club was run. As responders could select more than 1 time-point, our survey revealed multiple opportunities for students, at varying year levels, to gain exposure to a journal club.Journal clubs most commonly met either weekly (11 [31.4%]) or monthly (11 [31.4%]). Fortnightly gatherings were less common (6 [17.1%]), and some respondents reported “other” frequencies such as once every 2 months (1 [2.9%]), variably (3 [8.6%]), or unsure (3 [8.6%]). Journal clubs were reported as mandatory in 11 (31.4%) cases, while 21 (60.0%) were voluntary and 3 (8.6%) respondents indicated that they were unsure.The aims of existing journal clubs were to develop critical appraisal skills (20 [57.1%]), to provide a forum to discuss and debate medical topics using evidence (8 [22.9%]), to provide a means of disseminating information relating to good practice (3 [8.6%]), to encourage an appreciation of research (2 [5.7%]), and to keep students abreast of new research (1 [2.9%]). One person (2.9%) felt that the aims of a journal club differed depending on whether they were faculty or student-led, with the former being more focused on the teaching of critical appraisal, and the latter on fostering an appreciation of research.Our study demonstrated that journal clubs are popular in Australian medical schools, with over 4 in 5 of the surveyed universities implementing a journal club for the teaching of their students. Although no study has previously investigated the prevalence of journal clubs in this specific medical student cohort, the rate found in our study is similar to that reported for medical residency programs ,7.It is hardly surprising that the majority of journal clubs were found in metropolitan sites, and the reasons for this discrepancy are likely multifactorial. Firstly, rurally-based clinical schools contain fewer students than their metropolitan counterparts . Given tFurthermore, universities with a research focus—especially those affiliated with dedicated research institutions—are largely metropolitan, and therefore may place greater importance on journal clubs than less research-affiliated regional centres. Metropolitan sites are also more likely to offer specialty-based journal clubs given the greater number of specialty departments . Whatever the reason for the disparity, it is unlikely to have a significant effect on the academic performance of Australian rural students, given that they have demonstrated at least equivalence to their metropolitan counterparts .Our study found that the critical appraisal of evidence was the principal goal and the primary purpose of existing journal clubs. This is in keeping with previous research, including a seminal study of Linzer et al.  and otheWith regards to implementation, it was not surprising that journal clubs were predominantly clinician-led, as most medical students will require external input to decipher the content of journal articles. However, the popularity of student- or peer-led teaching activities has been growing since the 1990s, particularly in the medical field, as has the body of research exploring its benefits and limitations ,17. WhilMost journal clubs were held during the clinical years, which was also identified as being the ideal time during medical school by respondents. This was not a surprising finding given that students require a baseline level of knowledge achieved in their pre-clinical education years to understand the content of the articles reviewed. Additionally, when delivered during the clinical years, students would be able to apply knowledge obtained from journal articles to clinical interactions in the hospital and to patient care.The finding that journal clubs usually met weekly and fortnightly confirms the conclusions of a previous systematic review that weekly meetings were the most common, followed by monthly and fortnightly .While some journal clubs made student attendance mandatory, the majority did not. This difference could reflect both institutional culture and university requirements, with some clinical schools providing students the ability to attend opportunistically for furthering personal learning, while others may have mandated attendance as a ‘hurdle’ requirement in the curriculum. A systematic review by Deenadayalan et al.  in 2008 Despite a seemingly low response rate from eligible respondents, the survey was designed in way that accounted for non-responders, with in-built redundancy for each site. The response rate was also slightly higher than the expected response rate of 35% for web surveys .While under-sampling of academics was not an issue, it is possible that a small number of journal clubs— especially those that were led by students or allied health professionals—may have been missed. Similarly, fewer respondents were sourced per site regionally than in metropolitan areas. This again may have resulted in under-reporting. Finally, certain points that were emphasised in other reviews of journal clubs were not included in our survey, including the number of participants per session, the longevity of journal clubs, and the presence of external sponsorship.This nationwide study—the first of its kind—emphasizes the prevalence of journal clubs in Australian medical schools. Academics within these institutions believed that journal clubs are beneficial for the teaching of students, particularly with respect to critical appraisal skills. As research articles are being produced and disseminated at an exponential rate, teaching our future doctors the skills required to appropriately evaluate scientific articles is crucial for developing a generation of clinicians adept in providing evidence-based medicine. Our study provides a unique understanding of medical education leaders’ perceptions regarding the utility of journal clubs, and provides a framework of expert insights for the development of future journal clubs.


Esteemed readers and colleagues, I hope this message finds you and your families well in this challenging time of an ongoing global pandemic that has affected us all. I know this past year has brought about challenges beyond any of us could foresee but knowing the dedication and resilience of all of you, I know this is a temporary hurdle that all of us will not only overcome but will make us stronger and united. This past year has been another exceptional year for the International Brazilian Journal of Urology with the publication of a number of impactful scientific manuscripts and videos under the leadership of our new editor-in-chief Dr. Luciano A Favorito who instills great vision and foresight to our endearing journal for the many years to come. As is customary every year since taking on in my role as editor of the video section, I am pleased to announce the selection for best videos of the year for 2020. Many stringent criteria are used in making this selection including originality, innovation, and its inherent ability to optimize and positively impact patient care. Making this selection is truthfully never easy as we receive some truly outstanding videos every year and are privileged that international highly regarded colleagues specifically target our journal as their preferred journal for submission.On that note, I am pleased to announce the selection of the 1st prize for best video of the year to “Beyond traditional frontiers: robotic total pelvic exenteration” by Dr. Tamhankar and colleagues from the TATA Memorial Hospital in Mumbai, India published in the November-December 2020 (The selection for 2nd prize for best video of the year in 2020 is “Analysis of surgeon biometrics during open and robotic radical cystectomy with electromyography and motion capture analysis” by Dr. Baumgarten and colleagues from the University of South Florida departments of urology and physical therapy with this work being published in the January-February 2020 (Lastly but certainly not least, the selection for 3rd prize for best video of the year is awarded to “Single port robot-assisted transperitoneal kidney transplant using the SP surgical system in a pre-clinical model” by Dr. Garisto and colleagues in the department of urology at the Cleveland Clinic in Ohio. This work was published in the July-August 2020 (In conclusion, I would like to thank all of our readers for your strong support towards our journal and its video section, our success and recognition would not be possible without all of you. I strongly encourage international colleagues having interesting/innovative videos to consider submitting their work to our journal as we are continually seeking to highlight new approaches or surgical concepts as a means of offering our patients ultimately the most effective and minimally morbid surgical options in caring for their conditions.


When writing the “2019 State of the Journal Report” at this same time last year, we could not have predicted the global changes that would beset us with so many challenges from the emergence of the COVID-19 pandemic. Some of us lost loved ones, friends, and colleagues, while the entire world adapted to working from home, participating in remote classrooms, and adopting safety precautions as a new means of daily life. The research community was also affected, with the cessation of travel leading to virtual conferences. Thanks to the heroic efforts of many conference chairsYet, in the presence of a global pandemic, scientific contributions continued in the software and systems modeling community. The number of SoSyM submissions over the past year saw an increase, while the general health of the journal remains strong. Measures put in place recently, such as the second year of moving to six issues per year, have helped to reduce the time to publication significantly. The Open Access movement is also progressing, with Springer announcing new initiatives to make SoSyM publications more accessible to a broader community of researchers. The rest of this editorial summarizes the progress made by the journal during this unprecedented situation.Our hope is that you remain safe and have a productive 2021!The six SoSyM issues published in 2020 contained 17 Regular papers, 33 Special Section papers, 6 Theme Section papers, 4 Expert Voices, and 9 Guest Editorials. In total, 1587 pages were published in volume 19.We are very happy to report that the 2-year Impact Factor (IF) for SoSyM continues to be very respectable at 1.876 (previously at 2.66 in 2019 and 1.722 in 2018), with the 5-year IF holding at 1.915. Furthermore, the h-5 Google Scholar ranking places SoSyM at #12 among all conferences and journals related to software engineering and programming languages.There are two new positive “records” set for SoSyM in 2020 related to submissions and downloads. Over the past year, SoSyM received 372 submissions—the largest number for any year in our history (over 100 submissions over the average of the past three years). Furthermore, at the time of this writing, there were over 164,316 downloads from January through the end of November 2020. This is well beyond the 2019 download numbers  of 136,378. These two observations suggest the growing interest in SoSyM among the research community.The acceptance rate in 2020 was 19%, which is a respectable rate for a high-quality journal such as SoSyM. The average time from submission to the final decision (accept or reject) has slightly increased to 146 days (128 days in 2019 and 138 days in 2018).http://www.sosym.org/awards/.MODELS 2020 was originally planned to be held in Montreal, Canada, but due to the safety concerns with COVID-19, the conference was held virtually in October 2020. We thank the MODELS 2020 organizers (Eugene Syriani and Houari Sahraoui) and the PC co-Chairs (Silvia Abrahão and Juan de Lara) for collaborating with SoSyM. We were able to host another awards session with paper presentations of the Best SoSyM Papers over the past 10 years during a special virtual session of MODELS 2020. The selection was based on the ISI citation index among papers published in SoSyM since 2010. More information about the awards can be found at: SoSyM 2020 "Ten-year most influential Regular paper award" was given to:Journal on Software and Systems Modeling (SoSyM), Volume 9, Issue 2, pp. 257–280, Springer, April 2010.Jeff Offutt and Ye Wu, "Modeling presentation layers of web applications for testing," In: https://doi.org/10.1007/s10270-009-0125-4The SoSyM 2020 "Ten-year most influential Theme Section paper award" was given to:Journal on Software and Systems Modeling (SoSyM), Volume 9, Issue 4, pp. 427–451, Springer, September 2010.Nicolas Anquetil, Uira Kulesza, Ralf Mitschke, Ana Moreira, Jean-Claude Royer, Andreas Rummler, and Andre Sousa, "A model-driven traceability framework for software product lines," In: https://doi.org/10.1007/s10270-009-0120-9The Journal on Software and Systems Modeling (SoSyM), Springer, in press, 2020. https://doi.org/10.1007/s10270-020-00807-4Yinling Liu, Tao Wang, Haiqing Zhang, and Vincent Cheutet. “An improved approach on the model checking for an agent-based simulation system.” In: Journal on Software and Systems Modeling (SoSyM), Springer, in press, 2020. https://doi.org/10.1007/s10270-020-00819-0Simin Cai, Barbara Gallina, Dag Nyström, and Cristina Seceleanu. “Specification and automated verification of atomic concurrent real-time transactions.” In: Journal on Software and Systems Modeling (SoSyM), Volume 20, Issue 1, Springer, January 2021. https://doi.org/10.1007/s10270-020-00804-7Karim Jahed, Mojtaba Bagherzadeh, and Juergen Dingel. “On the benefits of file-level modularity for EMF models.” In: Journal on Software and Systems Modeling (SoSyM), Springer, in press, 2020. https://doi.org/10.1007/s10270-020-00815-4Stefan Götz, Matthias Tichy, and Raffaela Groner. “Claimed Advantages and Disadvantages of (dedicated) Model Transformation languages: A Systematic Literature Review.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 3, pp. 647–691, Springer, May 2020. https://doi.org/10.1007/s10270-019-00752-xAnthony Anjorin, Thomas Buchmann, Bernhard Westfechtel, Zinovy Diskin, Zinovy, Hsiang-Shang Ko, Romina Eramo, Georg Hinkel, Leila Samimi-Dehkordi, and Albert Zuendorf. “Benchmarking bidirectional transformations: theory, implementation, application, and assessment.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 3, pp. 741–762, Springer, May 2020. https://doi.org/10.1007/s10270-019-00764-7Milena Guessi, Flavio Oquendo, and Elisa Yumi Nakagawa. “Ark: A constraint-based method for architectural synthesis of smart systems.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 3, pp. 763–784, Springer, May 2020. https://doi.org/10.1007/s10270-019-00770-9Enyo Gonçalves, Camilo Almendra, Miguel Goulão, João Araújo, and Jaelson Castro. “Using empirical studies to mitigate symbol overload in iStar extensions.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 4, pp. 959–981, Springer, July 2020. https://doi.org/10.1007/s10270-020-00780-yNicolas Hili, Mojtaba Bagherzadeh, Karim Jahed, and Juergen Dingel. “A model-based architecture for interactive run-time monitoring.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 3, pp. 625–646, Springer, May 2020. https://doi.org/10.1007/s10270-019-00755-8Juan C. Vidal, Paulo Carreira, Vasco Amaral, Joao Aguiam, and João Sousa. “Towards high-level fuzzy control specifications for building automation systems.” In: Journal on Software and Systems Modeling (SoSyM), Volume 19, Issue 6, pp. 1483–1587, Springer, November2020. https://doi.org/10.1007/s10270-020-00806-5Bence Graics, Vince Molnár, András Vörös, István Majzik, and Dániel Varró. “Mixed-semantics composition of statecharts for the component-based design of reactive systems.” In: The continuous collaboration between SoSyM and the MODELS conference in organizing the SoSyM “Journal-First” was successfully continued. This enables authors of recent SoSyM papers to present their work across the core conference sessions at MODELS. Through this collaboration, SoSyM authors have the opportunity to reach a broader audience to present their work. This also benefits the MODELS conference program by including research talks that explore more depth through analytical and empirical evidence than can be presented in a traditional conference submission. The virtual nature of MODELS 2020 allowed for more SoSyM papers to be selected for presentation. At MODELS 2018, four articles were presented. At MODELS 2019, we increased this number to seven articles and at MODELS 2020 to ten articles (papers that were accepted from July 2019 through June 2020). The SoSyM “Journal-First” papers presented at MODELS 2020 were the following (note: Some of the papers are available online but have not yet received an assignment to an issue):Each year, Editors who served the SoSyM community for many years retire from the SoSyM Editorship with distinction of service and our deep appreciation. In 2020, Dorina Petriu announced that she desired to step down as an Editor after many years of service. Thanks Dorina for all of your contributions to SoSyM! As mentioned earlier in this report, SoSyM received a record number of submissions this year (372), which requires us to grow the Editorial Board. We are very happy to welcome the following new SoSyM Editors and look forward to working with them in the future.Juergen Dingel, Antonio García-Domínguez (twice!), Marcus Gerhold, Mario Gleirscher, Sylvain Hallé, Stefan Klikovits, Thomas Kühne, Hugo A. López, Florian Matthes, Libero Nigro, Bentley Oakes, Stefan Sauer, Harald Störrle, Valentín Valero, Steven van Kervel, and Simon Van Mierlo.A strong research community depends on the efforts of volunteers who help serve as reviewers.The software and systems modeling community has always risen to the request for help from SoSyM. We appreciate all of the help that the reviewers provided in service to the modeling community! We would also like to offer special recognition to the following reviewers, who were recommended as the SoSyM Best Reviewers of 2020, based on the technical depth and feedback provided to authors over the past year—congratulations! We will send a certificate of recognition to each of the following reviewers:http://www.sosym.org/people/.Rasmus Adler, Paulo Alencar, Ian Alexander, Joao Paulo Almeida, Ahmad Salim Al-Sibahi, Juliana Alves Pereira, Vasco Amaral, Elske Ammenwerth, Moussa Amrani, Daniel Amyot, Kelly Androutsopoulos, Anthony Anjorin, Muhammad Anwar, Vincent Aranega, Joao Araujo, Paolo Arcaini, Chetan Arora, Cyrille Artho, Wesley K. G. Assuncao, Colin Atkinson, Vanessa Ayala-Rivera, Thomas Baar, Onder Babur, Mojtaba Bagherzadeh, Mira Balaban, Torsten Bandyszak, Luciano Baresi, Kamel Barkaoui, Jiri Barnat, Angela Barriga, Francesco Basciani, María Bastarrica, Dinesh Batra, Steffen Becker, Mitra Tabaei Befrouei, David Benavides, Luca Berardinelli, Gabor Bergmann, Simona Bernardi, Ilia Bider, Robert Bill, Olivier Biot, Karsten Boehm, Francis Bordeleau, Dominik Bork, Artur Boronat, Saida Boukhedouma, Frederic Boulanger, Erwan Bousse, Drazen Brdjanin, Uwe Breitenbuecher, Ruth Breu, Jean-Michel Bruel, Davide Brugali, Hugo Bruneliere, Andrea Burattin, Erik Burger, Loli Burgueño, Arvid Butting, Cristina Cabanillas, Josè Campos, Laurent Capocchi, Jan Carlson, Victorio Carvalho, Roberto Casadei, Ana Cavalcanti, Graziana Cavone, Moharram Challenger, Mohammad Chami, Michel Chaudron, Franck Chauvel, Stanislav Chren, Antonio Cicchetti, Federico Ciccozzi, Robert Clarisó, Tony Clark, Peter Clarke, Manuel Clavel, Rolland Colette, Nelly Condori-Fernández, Maxime Cordy, Carl Corea, Mario Cortes-Cornax, Jesús Sánchez Cuadrado, Alberto da Silva, Fabiano Dalpiaz, Marian Daun, Nancy Day, Alfonso de la Vega, Juan de Lara, Romulo De Oliveira, Julien DeAntoni, Patrick Delfmann, Romain Demangeon, Joerg Desel, Xavier Devroey, Juri Di Rocco, Davide Di Ruscio, Marcos Didonet Del Fabro, Aleksandar Dimovski, Crystal Din, Juergen Dingel, Zinovy Diskin, Lydie Du Bousquet, Francisco Duran, Alexander Egyed, Maged Elaasar, Eduard Enoiu, Romina Eramo, Huseyin Ergin, Maria Escalona, Lorenz Esch, Elisabet Estevez, Bedilia Estrada, Dirk Fahland, Michalis Famelis, Anna Rita Fasolino, Andreas Fellner, Peter Fettke, Barabara Fila, Hans-Georg Fill, John Fitzgerald, Ulrich Frank, Martin Fränzle, Agnès Front, Frederik Gailly, Antonio García-Domínguez, Gregory Gay, Sebastien Gerard, Marcus Gerhold, Mario Gleirscher, Martin Gogolla, Aniruddha Gokhale, Thomas Goldschmidt, Claudio Gomes, Cesar Gonzalez-Perez, Catarina Gralha, Peter Green, Joel Greenyer, Paul Grefen, Raffaela Groner, Georg Grossmann, Lars Grunske, Esther Guerra, Renata Guizzardi, Jens Gulden, Jin Guo, Simon Hacks, Sylvain Hallé, Stefan Hallerstede, Oystein Haugen, Jane Hayes, Xiao He, Regina Hebig, Reiko Heckel, Constance Heitmeyer, Loic Helouet, Martin Henkel, James Hill, Georg Hinkel, Nico Hochgeschwender, Jennifer Horkoff, Christopher Hoyle, Ludovico Iovino, Muhammad Zohaib Iqbal, Karim Jahed, Amin Jalali, Phillip James, Cyrille Jegourel, Manfred A. Jeusfeld, Christian Johansen, Monika Kaczmarek, Bernhard Kaiser, Sungwon Kang, Dimitris Karagiannis, Gabor Karsai, Evangelia Kavakli, Timo Kehrer, Udo Kelter, Wael Kessentini, Djamel Eddine Khelladi, Ferhat Khendek, Marite Kirikova, Stefan Klikovits, Alexander Knapp, Jan Kofron, Shekoufeh Kolahdouz-Rahimi, Dimitrios Kolovos, Dimitris Kolovos, Harald König, Nikolai Kosmatov, Stefan Kugele, Thomas Kühne, Akhil Kumar, Katsiaryna Labunets, Yngve Lamo, Kevin Lano, Xavier Le Pallec, Choonhwa Lee, Henrik Leopold, Shuai Li, Sotirios Liaskos, Crescencio Lima, Lukas Linsbauer, Guanjun Liu, Malte Lochau, Hugo A. López, Ernesto López-Mellado, Florian Lorber, Mass Soldal Lund, Fernando Macías, Frédéric Mallet, Beatriz Marín, Andrea Marrella, Florian Matthes, Raimundas Matulevicius, Claudio Menghi, Gergely Mezei, Faida Mhenni, Judith Michael, Miguel Mira da Silva, Raffaela Mirandola, Michael Möhring, Brice Morin, Sebastien Mosser, Christian Moya, Seyyedeh Atefeh Musavi, Gunter Mussbacher, Andreas Naderlinger, Pascal Négros, Bernd Neumayr, Phu Nguyen, Phuong Nguyen, Libero Nigro, Alexander Nolte, Arne Nordmann, Markus Nüttgens, Bentley Oakes, Peter Ölveczky, Andreas Opdahl, Mert Ozkaya, Richard Freeman Paige, Marc Pantel, Jovanka Pantovic, Nick Papoulias, Raul Pardo, Chris Partridge, Oscar Pastor, Patrizio Pelliccione, David Pereira, Diego Perez-Palacin, Barbara Pernici, Justyna Petke, Alfonso Pierantonio, Ingo Pill, Elias Pimenidis, Geert Poels, Pascal Poizat, Fiona Polack, Gregor Polančič, Luigi Pomante, Saheed Popoola, Sam Procter, Luise Pufahl, Ahsan Qamar, Truong Ho Quang, Ansgar Radermacher, Akshay Rajhans, Alexander Raschke, Muhammad Rashid, Daniel Ratiu, Gil Regev, Gianna Reggio, Manfred Reichert, Hajo Reijers, Wolfgang Reisig, Guizzardi Renata, Jan Oliver Ringert, Roberto Rodríguez-Echeverría, Marcela Ruiz, Adrian Rutle, Renaud Rwemalika, Aymen Saied, Gwen Salaun, Cesar Sanchez, Jesús Sánchez Cuadrado, Kurt Sandkuhl, Alceste Scalas, Axel Scheithauer, Johannes Schobel, Stefan Schönig, Ulrik Schultz, Christoph Schütz, Cristina Seceleanu, Ed Seidewitz, Lionel Seinturier, Bran Selic, Sagar Sen, Eltefaat Shokri, Natalia Sidorova, Anthony Simons, Monique Snoeck, Stefan Sobernig, Pnina Soffer, Hui Song, Wei Song, Matthew Stephan, Janis Stirna, Volker Stolz, Harald Störrle, Eleni Stroulia, Daniel Strüber, Patrick Stünkel, Arnon Sturm, Andreas Symeonidis, Eugene Syriani, Gabor Szarnyas, Jérémie Tatibouet, Michael Tautschnig, Ramin Tavakoli Kolagari, Martin Thibault, Matthias Tichy, Ulyana Tikhonova, Massimo Tisi, Saurabh Tiwari, Jake Tom, Hanh Nhi Tran, Javier Troya, Christos Tsigkanos, Valentín Valero, Antonio Vallecillo, Han van der Aa, Steven van Kervel, Simon Van Mierlo, Irene Vanderfeesten, Juan Manuel Vara, Tullio Vardanega, Daniel Varro, Gabriel Wainer, Pengyuan Wang, Barbara Weber, Ron Weber, Heike Wehrheim, Marco Wehrmeister, Jun Wei, Andrew Weinert, Georg Weissenbacher, Bernhard Westfechtel, Anton Wijs, Manuel Wimmer, Karsten Wolf, Uwe Wolter, Murray Woodside, Andreas Wortmann, Franz Wotawa, Jin-Long Wu, Sobhan Yassipour-Tehrani, Sira Yongchareon, Shin Yoo, Bahman Zamani, Anna Zamansky, Jelena Zdravkovic, Bernard P. Zeigler, Man Zhang, Alois Zoitl, Athanasios Zolotas, Steffen Zschaler, and Albert Zuendorf.Below is a list of those who reviewed one or more papers for the journal in the last year. The complete list of reviewers can also be found on our website Expert's Voice“The triptych of conceptual modeling—A framework for a better understanding of conceptual modeling” by Heinrich C. Mayr and Bernhard ThalheimEMMSAD 2019 Special SectionGuest Editors: Iris Reinhartz-Berger and Jelena ZdravkovicRegular Papers"Generation of hazard relation diagrams: Formalization and tool support" by Bastian Tenbergen and Thorsten Weyer"A framework for automated multi-stage and multi-step product configuration of cyber-physical systems" by Safdar Aqeel Safdar, Hong Lu, Tao Yue, Shaukat Ali, and Kunming Nie"On the benefits of file-level modularity for EMF models” by Karim Jahed, Mojtaba Bagherzadeh, and Jürgen DingelThe contents of this issue are as follows:We wish you a Happy New Year with the hope that you enjoy reading the papers in this issue!Huseyin Ergin, Jeff Gray, Bernhard Rumpe, and Martin Schindler


The optimization of the thermal treatment of cationic starch in the paper industry offers the opportunity to reduce the energy consumption of this process. Four different industrially relevant cationic starches, varying in source, cationization method and degree of substitution were treated by a steam-jet cooking procedure, comparable to industrially employed starch cooking processes. The influence of the starch properties and cooking parameters on the adsorption behavior of the starches on cellulosic pulp was investigated. The adsorbed amount was affected by the cooking temperature and the type of starch. For some starch grades, a cooking temperature of 115 °C can be employed to achieve sufficient starch retention on the pulp fibers. The energy consumption could further be reduced by cooking at higher starch concentrations without loss of adsorption efficiency. Besides cellulosic fibers and mineral fillers, starch is one of the main components in paper-based products. In the paper industry, starch derived from corn, potato, wheat as well as tapioca is used, depending on the region. Starch consists of amylose, which has a mainly linear structure with few long chain branches, and of amylopectin, which has a high number of short-chain branches and higher molecular weights ,2. The r2 of industrial relevant cationic starches adsorbing to the surface of cellulose thin films which is a 2D-system [Starch used in the wet-end of the paper machine as a dry strength and retention agent commonly contains cationic groups which have been introduced through chemical modification of the native starch ,4. The cD-system . AlthougD-system ,27 in whIn the current study, the effect of cooking parameters on the adsorption efficiency of cationic starch on cellulosic fibers was investigated. A jet-cooking procedure comparable to the process used in the paper industry was used. Four starches used in the paper industry, differing in the cationization process (wet and dry), degree of substitution (DS), and source (potato and corn), were studied. Their adsorption behavior on pulp fibers was investigated. Experiments were performed at different cooking temperatures, focusing on determining the lowest temperature necessary to achieve maximum cationic starch retention. As the cooking procedure resembles the process used in the paper industry, the results will give an understanding of how the cooking conditions affect the adsorption behavior.Wet-cationized potato starch P-W1 and P-W2 were obtained from Südstärke GmbH ; dry cationized potato (P-D) and corn (C-D) starches were obtained from Roquette Frères . The experiments were performed using dried, bleached, unrefined birch, and aspen wood Kraft pulp , cationic demand 4 meq/g) provided by a local pulp mill in Austria.Sodium chloride and potassium chloride were purchased from Herba Chemosan Apotheker-AG  (purity: 99.97%) and Fluka Analytical (purity: >99%), respectively. Iodine–potassium iodide solution acc. to Lugol was obtained from Carl Roth GmbH + Co. KG .x(N)), the degree of substitution (DS) was calculated according to following formula:rM(anGlu), rM(N), and rM(GTAC) are the relative molecular weights of anhydroglucose, nitrogen, and glycidyltrimethylammonium chloride, respectively. The results for the different starches are depicted in The nitrogen content of the samples was determined by elemental analysis using a CNHS Elemental Analyzer, Vario MICRO Cube . Starch samples were dried for 24 h at 100 °C before the measurements. From the resulting percentage nitrogen content  to prevent sedimentation. It was attached to a Netzsch Mohno pump  with flow rates reaching up to 50 L/min. The pressure of the slurry inlet was controlled by a Jordan GP valve . The steam was generated by a steam generator  which generates pressures ranging from 0.1 to 6 bars. In order to keep the aperture running smoothly, the pressure was always kept below 3 bars. In a hydro THERMAL M101 hydroheater reaction chamber , the steam was mixed with the starch slurry inlet stream. Pressure and temperature could be changed via a control panel. The flow rate was set to 6 L/min at a pump frequency of 9.7 Hz. The temperature used to cook the starch slurry was varied between 115 and 130 °C, dependent on the experiment. The first few hundred milliliters were discarded, and then the cooked starch solutions were transferred to insulated bottles. A flowchart in The cationic starch powder was placed into a 25 L plastic canister, and 5 L of deionized water containing KCl (40 mg/L) and NaCl (120 mg/L) was added. The mixture was shaken vigorously to ensure a homogenous distribution of the starch. After transferring the starch slurry into the storage vessel of the steam jet cooker (capacity 50 L), it was stirred at 50 rpm with a EUROSTAR 20 stirrer (IKAPulp panels (35 g) were cut in small pieces (<2 cm × 2 cm), equilibrated in 1 L of deionized water containing KCl (40 mg/L) and NaCl (120 mg/L) (conductivity of approximately 30 mS/m), and stirred for 24 h with a KPG stirrer at room temperature to guarantee complete swelling of the unrefined pulp fibers. Then, 250 mL of water was removed from the beaker, and a sample was taken for background determination. The cooked starch solution was diluted with the electrolyte solution to give a final concentration of 3.5 to 4.2 g/L and stirred with a magnetic stirrer at 500 rpm for 60 min at room temperature. A sample of the diluted starch solution was taken for analysis; 250 mL of the diluted starch solution was added to the pulp and mixed throughout the experiment at 500 rpm with a KPG stirrer. Samples were taken after 1, 5, 10, and 15 min. The final ratio of starch to pulp was 25 to 30 mg/g in all the adsorption experiments, which is the upper limit of cationic starch used in industrial applications. The experiments were performed in triplicate. After the adsorption experiments, the starch solution was drained with a sieve, and the pulp was squeezed by hand to remove any excess solution. A petri dish was filled with the pulp samples which were allowed to dry at room temperature. These samples were subject to scanning electron microscopy and ζ-potential measurements. For comparison, pure pulp was treated the same way.c is the concentration of starch in mg/mL, l is the optical path length, which was 1 cm in all measurements, Anm660 is the absorbance at 660 nm, and The amount of starch which was adsorbed to the pulp was determined by measuring the remaining starch concentration in the solution. Samples were taken 1, 5, 10, and 15 min after the starch solution was added to the pulp. The samples were diluted to obtain starch concentrations between 10 to 100 mg/L; 2.7 mL of starch solution was put into a polystyrene cuvette, and 0.3 mL of Lugol solution was added. For the measurement, a UV/VIS Spectrometer “Lambda 25”  was used. The measurement was made from 450 to 800 nm with a scan speed of 480 nm/min in absorption mode using a 1 nm slit. The data were collected with the software “Lambda 25”. Starch concentrations were calculated by Lambert–Beer’s Law:t 660 nm .618nmA and 550nmA) using a UV/VIS Spectrometer “Lambda 25” . Their ratio, (R) 618nmA/550nmA, was used to calculate the fraction of amylose (P) using following formula:The amylose content was estimated using the method described by Hovenkamp-Hermelink . Starch TM 3 . Four measurements were done and averaged. The pulp was treated with potato starches and corn starch cooked by steam jet cooking at 115 and 125 °C, respectively. Approximately 0.5 g of the sample  which produced steam to dissolve the starch. The steam cleaner was filled with 100 mL deionized water, and the steam was injected into the starch slurry until its tank was empty (approx. 3 min.). Afterward, the starch solution was homogenized using a hand blender  for one minute. The starch solutions were diluted with deionized water to obtain final concentrations of 1 mg/mL for particle size and ζ-potential measurements as well as for the determination of the conductivity of the starch solutions. All the following experiments were performed in triplicate. The hydrodynamic radius, conductivity, and ζ-potential were measured at 25 °C using a Litesizer 500 . Starch samples containing 1 mg/mL starch in deionized water were filled into cuvettes and allowed to equilibrate at 25 °C for at least five minutes before the measurement. KalliopeScanning electron microscopy (SEM) images of gold-sputtered samples were obtained with a TESCAN VEGA3 .Different types of steam-jet cooked cationic starches were adsorbed on cellulosic pulps. The starches (two potato and two corn starches) featured a DS between 0.037 and 0.055 and were either dry or wet cationized. These starches were subjected to dissolution via steam-jet cooking in deionized water with defined ionic strength that matches typical conditions present in process waters. The temperature , as well as the concentration of the starches (3.5 and 7 wt.%) were varied and their influence on the adsorption behavior investigated. Before addition to the pulp fiber suspension, the starch solutions were diluted. Retention was monitored and quantified by visible light absorption at 660 nm of the starch–iodine complex. Adsorption times were varied between 1 and 15 min as these are typical times for starch adsorption in an industrial context. The experiments were performed at relatively high starch-to-pulp ratios.The starches were cooked at 125 °C at a concentration of 3.5 wt.%. Subsequently, the influence of adsorption time on the adsorption efficiency, i.e., how much of the starch was retained on the fibers, was explored. A starch-to-pulp ratio of 25 to 30 mg/g was chosen in the experiments, and the adsorption time was varied between 1 and 15 min. Most of the starch was already adsorbed within the first minute of the experiment. Dry-cationized corn and potato starches showed a significant reduction of adsorbed material between 10 and 15 min and between 5 and 10 min, respectively. This phenomenon was related to the replacement of adsorbed starch clusters by single starch molecules . The res2/g according to [2.The starch retentions translate to maximum adsorption of 10 to 24 mg starch/g of pulp . Assuminrding to  for unreIn industry, the cooking temperature and concentration are directly correlated with the energy consumption of the starch cooking process. A decrease in cooking temperature is therefore an important factor in reducing energy costs. Steam-jet cooking temperatures of 120 and 115 °C were applied for the three potato starches. Adsorption time was set to 15 min in this set of experiments. The potato starches showed a clear increase in adsorption efficiency when the cooking temperature was reduced from 125 to 115 °C . The effThe energy input for the dissolution of starch in the paper industry can further be reduced by jet-cooking increased starch concentrations. The experimental conditions of the adsorption experiments were kept the same, only the concentration of starch during the cooking procedure was doubled. The increased concentration caused a significantly increased adsorption efficiency for dry-cationized corn starch (C-D) . HoweverDifferent absorption maxima of the iodine complexes of amylose and amylopectin enabled the observation of changes in composition during the adsorption experiments. The absorption maximum of the starch remaining in solution shifted during the adsorption. This indicated that amylopectin and amylose were not adsorbed to the same extent. The shift of the absorption maximum to lower wavelengths indicated that the ratio in the solution changed to higher amylopectin contents. In turn, there was an increased amount of amylose adsorbed onto the pulp fibers. The amylose content in the drain water was estimated according to Hovenkamp-Hermelink  Table 4Table 4. The electrostatic interaction of cationic starches with cellulosic fibers is related to their charges. As a measure of the effective charge on the surface, the ζ-potential of starches in pure water was determined . The ζ-pIn order to evaluate the effect of cationic starch on the charge properties of pulp, the ζ-potentials of untreated pulp as well as those treated with different starches were determined. All samples showed a reduction of the negative charge on the fibers a. The chPulp fibers with adsorbed starches were dried and monitored by SEM. For all samples, starch adsorbed to the pulp was observed . The appFour different, industrially relevant cationic starches were studied. The starches differed in source (corn and potato) and cationization process (wet and dry) and had a slightly different degrees of substitution. Depending on the type of starch, different retention efficiencies were observed. Determination of the amylose content  revealedIn the current study, the adsorption behavior of four different industrially relevant cationic starches to cellulosic pulp was studied. The starches were pretreated by a steam-jet cooking method which is comparable to the cooking process used in the paper industry. The presented results have improved relevance to industrial applications contrary to experiments performed with laboratory cooking methods. The adsorption efficiency is related to the amylose content of the starches as well as their degree of substitution. A higher amylose content results in increased adsorption whereas the amount of adsorbed starch decreases with increasing degree of substitution. Besides these differences, the adsorption of the cationic starches is also affected by the cooking conditions. Current results suggest that the cooking temperature of cationic potato starch can be reduced to 115 °C without a reduction of adsorption efficiency. Additionally, an increased concentration only negatively affects the adsorption of dry-cationized potato starch, whereas the adsorption of dry-cationized corn starch increases. A reduction of cooking temperature as well as an increase in starch concentration during the cooking procedure significantly reduced the energy consumption of this process.


The use of the vancomycin wrap to pretreat the hamstring graft in anteriorcruciate ligament reconstruction (ACLR) has grown in popularity since it wasfirst described in 2012 and has significantly reduced rates of postoperativeinfection. However, it remains unknown if this antibiotic treatment affectsthe molecular composition of the graft.To establish whether treatment with vancomycin at 5 mg/mL, the most commonlyused concentration, alters the molecular function of the hamstring graft inACLR.Controlled laboratory study.Surplus hamstring tendon collected after routine ACLR surgery was used for invitro cell culture and ex vivo tissue experiments. Vancomycin was used at 5mg/mL in RPMI or saline diluent to treat cells and tendon tissue,respectively, with diluent control conditions. Cell viability at 30, 60, and120 minutes was assessed via colorimetric viability assay. Tendon cellstreated with control and experimental conditions for 1 hour was evaluatedusing semiquantitative reverse transcription analysis, immunohistochemistrystaining, and protein quantitation via enzyme-linked immunosorbent assay forchanges in apoptotic, matrix, and inflammatory gene and proteinexpression.P < .05); however,this was not sustained at 120 minutes. Vancomycin-treated tendon tissueshowed no significant increase in apoptotic gene expression, or apoptoticprotein levels in tissue or supernatant, ex vivo. Vancomycin was associatedwith a reduction in inflammatory proteins from treated tendon supernatants.Vancomycin treatment at 5 mg/mL significantly reduced tenocyte viability invitro after 60 minutes of treatment (Vancomycin did not significantly alter the molecular structure of thehamstring graft. Reductions in matrix protein and inflammatory cytokinerelease point to a potential beneficial effect of vancomycin in generating ahomeostatic environment.Vancomycin ACL wrap does not alter the molecular structure of the ACLhamstring graft and may improve graft integrity. Theminimum inhibition concentration required for Staphylococcus aureus is0.5 μg/mL and is in the range of 0.25 μg/mL to 2.0 μg/mL for other bacteria.3 It is widely used in many forms in orthopaedic surgery  infusion to treat prosthetic joint infection, and topicalpowder on spinal surgery wounds), with results showing that it reduces infectionsignificantly.24 Anumber of other surgical specialties utilize antibiotics and antimicrobials, eithertopically on wounds or in solution to immerse and wrap implants before surgery, andreports have shown significant reductions in infection.33 Cardiothoracic surgery has been atthe forefront of this, with surgeons applying vancomycin powder to sternotomy woundsfollowing the results of a seminal paper in 198933 and now implanting cardiac electronic devices enveloped in a degradableantimicrobial sleeve.30Vancomycin is a glycopeptide antibiotic originally introduced to treatmethicillin-resistant 34 Since then, there have been a number of published studies and reviews that havedemonstrated significantly reduced postoperative infection rates in ACLR.2534The specific practice of wrapping the donor graft in a vancomycin-soaked sterile swabbefore insertion in ACLR surgery has steadily increased since 2012 when the “vancomycinwrap” was first described.29 A human in vitro study has shown vancomycin toxicity to chondrocyte andosteoblast-like cells, via a reduction in cell DNA, at doses of 250 μg/mL and 125 μg/mLfor osteoblast and chondrocytes, respectively, after 48 hours of treatment.4 Two further studies have concluded that vancomycin is not toxic at doses up to 16μg/mL for 36 hours in an ex vivo chondrocyte model12 and up to 1000 μg/mL for 72 hours in an in vitro osteoblast model.13 Porcine tendon models show that vancomycin is effective at eliminating bacterialcontamination at 5 mg/mL after 20 minutes of soaking and that it has no effect on thebiomechanical properties at doses up to 10 mg/mL.28 Bovine studies have demonstrated that tendon can act as a reservoir forvancomycin, releasing the antibiotic for up to 24 hours into the joint, changing asource of infection into an intra-articular prophylactic vehicle.15The molecular effects of vancomycin on human and animal periarticular tissues, includingtendon, has a limited evidence base. Porcine chondrocyte death was significantlyincreased after exposure to vancomycin at doses of 5 mg/mL or higher.The current study aimed to determine whether treatment with vancomycin at 5 mg/mL, theclinically used concentration, alters the structural or molecular function of thehamstring graft in ACLR using human tendon in vitro and ex vivo models.Surplus human tendon tissue was obtained during surgery for ACL hamstringreconstruction. Patients were screened and the tissue discarded if there was ahistory of surgery to that joint, infection, or malignancy. The tissue was usedfor ex vivo and in vitro experiments as outlined below. Tissue collectioncomplied with local research ethics committee approval. All tissue was collectedunder ethics REC 14/WS/1035.2. Cells were passaged with trypsin atsubconfluency and used at second or third passage for in vitro experiments.Tenocyte cells were derived from surplus hamstring tendon tissue. Cell culturewas maintained for 28 days in RPMI supplemented with 10% fetal calf serum, 100U/mL penicillin, 100 μg/mL streptomycin (Gibco), at 37°C in a humidifiedatmosphere of 5% CO2.Supernatants were aspirated and stored for future protein analysis and replacedwith RPMI for 16 hours of culture to allow for gene expression changes andcytokine release. After the 16-hour incubation, supernatants were aspirated andstored for future analysis and the tendon tissue was transferred to RNALater(Ambion) or 4% buffered formalin for quantitative polymerase chain reaction(qPCR) and immunohistochemistry analysis, respectively.Surplus tendon tissue from separate donors was cut into 1-cm sections for ex vivoexperiments. These sections were treated with vehicle control and experimentalconditions for 1 hour at 37°C in a humidified atmosphere of 5% CO2, before use. The culturemedia was aspirated and discarded and replaced with RPMI control andexperimental conditions, vancomycin 5 mg/mL in RPMI diluent for 30, 60, and 120minutes at 37°C, 5% CO2. Supernatants were aspirated and replacedwith sterile filtered MTT for 3 hours. Cells were then washed with sterile RPMIand incubated with DMSO for 10 minutes to dissolve the formazan product. Thiswas transferred into a 96-well plate (100 μL per well in duplicate) and read onan MTX TC II microplate reader (Dynex Technologies) at 540 nm.To assess the effect of vancomycin on tenocytes, cells were exposed to theclinically relevant concentration of 5 mg/mL of vancomycin for up to 120minutes. The in vitro effect was evaluated using3--2,5-diphenyltetrazolium bromide cell viabilityassays . Tenocytes were plated at 25,000 cells/well in a24-well plate for 48 hours at 37°C, 5% COAppendix 1 (available in the online version of this article).The gene expression of 9 genes involved in the intrinsic and extrinsic apoptoticpathways and extracellular matrix protein collagen 1α were assessed.Vancomycin-treated, vehicle control, and untreated tendon explant tissue inRNALater (Ambion) from 5 donors was used for qPCR analysis. The untreatedcondition allowed for any gene expression changes already present in the tendonto be evaluated. RNA was extracted using PureLink RNA Mini Kit (Thermo Fisher)as per the manufacturer’s instructions. The High Capacity cDNA ReverseTranscription Kit (Thermo Fisher) was used to prepare cDNA as per themanufacturer’s instructions on a thermal cycler (Applied Biosystems). PCRanalysis was performed with PowerUP SYBER Green Master Mix (Thermo Fisher), induplicate. Primers (Integrated DNA Technologies) are listed in Quantitation of the inflammatory proteins interleukin 6 (IL-6), interleukin 8(IL-8), MMP3, CCL2; extracellular matrix protein collagen 1α; and mitochondrialsignally apoptotic protein cytochrome C were determined in supernatants fromcontrol and treated tendon explants with vancomycin 5 mg/mL in 0.9% salinediluent, using ELISAs as per the manufacturer’s instructions . Samples were run in duplicate on a 96-well plate andread on an MTX TC II microplate reader (Dynex Technologies).Caspase 3 is an enzyme common to both intrinsic and extrinsic apoptosis pathways.Levels of cleaved caspase 3 in supernatants from treated and control tendonexplants were determined by luminescence assay  as perthe manufacturer’s instructions. Supernatant was diluted 1:1 with Caspase-GLO3/7 reagent, incubated for 1 hour at room temperature, and the luminescencedetected on a MicroBeta TriLux 1450 plate reader (Perkin Elmer Life Sciences).All samples were run in duplicate.Treated and control tendon explant tissue, fixed in 4% buffered formalin andembedded in paraffin, was immunohistochemically stained for caspase 3 . Sections of tissue were cut to 5-μm thickness (LeicaMicrosystems), paraffin removed by xylene, and rehydrated in graded alcohol.2O2, and nonspecific antibody binding was blockedwith 2.5% horse serum in tris-buffered saline (TBST) buffer for 30 minutes.Antigen retrieval was performed in 0.01 M citrate buffer for 25 minutes in amicrowave. Tissue sections were incubated with primary antibody diluted 1:125 in2.5% (w/v) horse serum/TBST overnight at 4°C. After 2 washes, the slides wereincubated with a Vector ImmPRESS Reagent kit as per the manufacturer’sinstructions for 30 minutes. The slides were washed and incubated with VectorImmPACT DAB chromagen solution (1 drop per 1 mL diluent) for 30 seconds,followed by extensive washing with water. Finally, the sections werecounterstained with hematoxylin, dehydrated in graded alcohol, and mounted inDPX with a coverslip.Endogenous peroxidase activity was quenched with 3% (vol/vol)HTissue sections were imaged under a light microscope  at 10× and40× magnification and compared with Isotype controls. Quantification of stainingwas performed in 2 stages. First, semiquantitative staging was performed on 5random high-powered fields, grading the percentage of positively stained cellsin the filed using the Modified Bonar Score .Second, the total number of positive and negative stained cells in each of the 5high-powered fields was counted to generate the mean percentage positive forstained cells.t test. Multiple comparisons wereperformed between the untreated tendon and tendon treated with vancomycin insaline compared with tendon in saline alone, as this is current clinicalpractice.GraphPad Prism software (Version 6) was used for all statistical analyses, anddata were reported as mean and standard error of the mean unless statedotherwise. Comparisons between treatment groups were made using 1-way analysisof variance or Student P < .05). However, this was not the case with treatmentat 30 and 120 minutes  staining, after vancomycin treatment.IHC staining showed that vancomycin treatment resulted in no disruption to theuniform collagen structure of tendon and suggested a trend toward more positivestaining for caspase 3 in the vancomycin-treated tissue, but this was notsignificant , Cand DThe expression of 9 apoptotic genes was also measured after ex vivo treatment oftendon with experimental conditions. All results were normalized to freshuntreated graft tendon. There was no significant increase in pro-apoptotic geneswith vancomycin treatment compared with untreated or saline-treated tendon. TherewVancomycin treatment caused no significant changes in tendon matrix geneexpression by measuring the expression of genes collagen 1α, collagen 3α,decorin, and tenascin C. There was a significant reduction in collagen 1αprotein in supernatants from tendon treated with vancomycin compared with thosetreated with saline alone .Ex vivo vancomycin treatment of tendon showed a significant reduction in thelevel of inflammatory cytokine IL-6 being released into the supernatant whencompared with saline treatment . No diff2534 One study reported infectionrates in the control group, treated with prophylactic IV antibiotics alone, as 1.4%(n = 285) compared with 0% in patients who were treated with prophylactic IVantibiotics in combination with vancomycin wrap (n = 870).34 A further study that conducted a postoperative follow-up of 1300 consecutiveACLRs using the vancomycin wrap in combination with standard IV antibioticprophylaxis reported zero postoperative infections against a retrospective controlgroup (n = 240) that reported infections in 2.4% of patients.27 A more recent study that looked at 1640 patients found the use of avancomycin wrap during ACLR was associated with a 10-fold reduction in postoperativeinfection (0.1% vs 1.2%).5The first description of the “vancomcyin wrap” for ACLR was in 2012; since then, anumber of studies have demonstrated its effectiveness in combination with usual IVantibiotic prophylaxis at reducing postoperative infection rates to almost0%.Our study is the first to evaluate the molecular and structural effects thatvancomycin has on a human hamstring graft for ACLR. The results of the current workindicate that vancomycin appears safe and has no detrimental effects on the cellularor molecular structure of the tendon graft used for ACLR.12 above the minimum inhibitory concentration for Staphylococcusaureus.3 It remains unclear from the published literature how much of the antibioticis absorbed both by the sterile swab and by the tendon itself and therefore whatconcentration the tenocytes are exposed to. One study reported that the sterile swababsorbs an average of 7 mL of the 100-mL solution containing vancomycin at 5 mg/mL.34 Bovine studies specifically looking at absorbance and elution of vancomycinfrom tendon have demonstrated that both of these characteristics are affected bygraft size and rinsing,15 which occurs in clinical practice once implanted, with arthroscopic washoutof the joint. It is challenging to develop a model that accounts for all of thesevariables. We therefore submerged uniform size tendon explant pieces in vancomycinor saline for 1 hour. This eliminated any effect drying may have had on the tendonand was long enough to encompass reported average times from graft harvest toimplantation of 30 minutes .16 The graft was then cultured for up to 16 hours after 1 hour of treatment toassess the effect of vancomycin on tendon gene expression and cytokine release. Weused this as our “surgical scenario” model and believe this accurately reflectscurrent practice and gives confidence that our molecular findings translate toeveryday clinical practice.The addition of vancomycin at the commonly used clinical dose did result in areduction in tenocyte viability at 60 minutes. It is common in an in vitro model toexperience biological variability and we did not see this reduction sustained after30 or 120 minutes of treatment. Previously published literature that used the sameassay to assess chondrocyte viability found vancomycin to be safe at doses up to 16mg/L over 36 hours of treatment,Treatment with vancomycin did not appear to initiate cell death as there was noincrease in cytochrome C in supernatant and no increase in caspase 3 protein inexplant tissue. Interestingly, there may be a small but beneficial effect ofvancomycin in decreasing caspase 3 in supernatants from treated tendon, mirroringthe significant reduction in the gene expression of caspase 3. Furthermore, therewas little evidence that vancomycin induced any upregulation in apoptotic geneexpression compared with saline-treated grafts.The primary function of the tendon graft in ALCR is to transfer mechanical load.Although the current study did not directly measure the biomechanical properties ofthe tendon graft after vancomycin treatment, histological studies indicatevancomycin treatment does not affect the integrity of the graft structure.Furthermore, exploration of the effect of vancomycin treatment on the matrixcomponent of the graft after treatment demonstrated no significant difference inmatrix gene expression compared with untreated tendon or saline-treated tendon. Itis important to note, however, that there was a small but significant reduction incollagen 1α protein release in vancomycin-treated tendon supernatants compared withsaline treatment. It is postulated that this may demonstrate lower collagen 1αprotein breakdown from the tissue explant into the supernatant after vancomycintreatment and thus may reflect a positive effect of vancomycin treatment.1 In a sepsis model, however, vancomycin was found to have proinflammatoryeffects on the innate immune system.6 We therefore investigated the inflammatory effect vancomycin had on tendon.Our results show that vancomycin treatment reduced inflammatory cytokine releasefrom tendon compared with saline alone, significantly IL-6. Previous work has shownthat inflammation has a negative effect on the health of a tendon and IL-6 isinvolved in the development of tendinopathy.22 The “vancomycin wrap” has the potential to create an anti-inflammatoryenvironment.Vancomycin, as well as being antimicrobial, has also been shown to have immunemodulating potential. In inflammatory mediated conditions, it has been shown to actvia alterations in the host T-cell population and lead to reduced inflammation.P < .01).25These results suggest vancomycin treatment is not detrimental to the cellularviability of the tendon graft but may indeed have small beneficial effects pointingtoward a homeostatic molecular environment to encourage graft viability. Thereduction in collagen 1α release and inflammatory cytokine release indicate reducedcellular stress and may be linked with the reduction seen in the apoptotic geneexpression of caspase 3. A recent retrospective cohort study reviewed 1779 patientswho underwent ACLR with vancomycin soaking of the hamstring graft employed in 853 ofthese cases. Over a 5-year period, whereby 100 patients were randomly selected forfollow-up each year, graft failure and re-rupture rates were reported to besignificantly lower in the vancomycin wrap group; 8 failures out of 257 versus 16failures out of 167 patients in the control group .32 Furthermore, infection after ACLR can be caused by multiple pathogens thatmay not be susceptible to vancomycin and the increasing use of 1 antibiotic as localprophylaxis may begin to select out for non-Staphylococcalinfections, which does not constitute resistance but may have implications forclinical treatment protocols should infection occur.17Risk factors and prevention strategies for postoperative infection in ACLR aremultifactorial, with longer surgical times and higher body mass index both shown tobe independent predictors.20 Animal studies have demonstrated that once wrapped in a vancomycin solution,the ACL graft can act as a reservoir, continuing to release the drug over 24 hoursat gradually decreasing levels, below a dose considered toxic to cells.15 Exposing tissues to prolonged subtherapeutic levels of a drug is a known wayto establish resistance.2 Future evaluation on the safety of the vancomycin wrap in ACLR could includeserum and synovial drugs levels after surgery to investigate this.Antibiotic resistance is an important consideration as an increasing number ofantibiotics are being used in the perioperative period as prophylaxis. Data fromcardiothoracic surgery using vancomycin paste in sternotomy wounds have not foundantibiotic resistance to be an issue given that topical use does not lead totherapeutic serum levels of the drug.There are limitations to this work, primarily with the tendon explant model. Thereare many variables involved in the vancomycin wrap during surgery: the volume ofantibiotic absorbed by the swab and by the graft, both influenced by the volume oftissue and rinsing during the arthroscopic procedure, and the effect of drying ofthe graft before implantation under the lamina flow. It is challenging to create amodel that encompasses all of these variables. We believe the model we usedaccurately reflects the effect of the antibiotic alone on the graft. Further studiesand clinical follow-up are recommended to investigate the tendon graft biomechanicalproperties after treatment, if there is any association with reduced graft failureand any indications of antibiotic resistance.No detrimental effect of vancomycin treatment was found in terms of cellularapoptosis, matrix protein expression, and inflammatory cytokine levels, comparedwith saline treatment, in hamstring ACL graft. Additionally, data from the currentstudy provide minor indications for the beneficial effect of vancomycin treatment onACL graft integrity by promoting a homeostatic molecular environment.Click here for additional data file.Supplemental material, sj-pdf-1-ajs-10.1177_0363546520981570 for Vancomycin Wrapfor Anterior Cruciate Ligament Surgery by Caroline M. Atherton, Simon J.Spencer, Katy McCall, Emma Garcia-Melchor, William J. Leach, Michael Mullen,Brian P. Rooney, Colin Walker, Iain B. McInnes, Neal L. Millar and Moeed Akbarin The American Journal of Sports Medicine


As we were all celebrating the end of 2019 and the start of 2020 with all the promises of a new year and renewal, little did we know what was coming a few months later. Slowly but surely, the world became infected with the coronavirus disease 2019 (COVID-19), and countries in their efforts to control the virus, shut down their economies and people’s lives. The full impact of COVID-19 hit South Africans with the state of disaster, which started on 15th of March this year. Since then we have learned to live with the virus and everyone in all walks of life has learned to adapt. Learning went online, work went online, and we have learnt to live differently from the way we did before the pandemic.As high-income countries like the United States of America and those in Europe battle a second wave of the virus, we hope that we will be spared a second wave with a high number of cases. Our current problems are to complete the academic year for those at schools, colleges and universities and to cope with a devastated economy. Our thoughts are continually with those who have lost their loved ones to the virus and those who have suffered so badly economically. We also keep all front-line healthcare workers and essential workers in our thoughts as they continue to keep the rest of us safe. I hope that all of us will continue with safe practices until such time as we come out of this pandemic.South African Journal of Physiotherapy (SAJP) has continued to thrive this year. For this, we owe a heartfelt thanks to our authors who have kept the submissions coming in; our reviewers who carefully consider the submissions and make appropriate recommendations and finally but not least our publishers who have often had to work remotely and who keep the wheels of the journal turning.The We are receiving more submissions from a greater variety of authors, not only from South Africa but slowly and surely from other countries as well. This is wonderful and we will continue to encourage this in all ways possible. The number of submissions has also increased and again we need to encourage this. The variety of topics published is increasing and there really should be something of interest for all our readers.We have published two ‘state-of-the-art’ articles this year and are awaiting the promises of more that have been made by some of our senior researchers. We continually hope that we get bigger studies to publish and that researchers increasingly consider the SAJP as a journal of choice. To do this, we have to continue to improve the standard, and trust that by being on international indices our work is noticed by a larger audience.This year we have also included additional checklists for authors, so that prior to submission they can check their articles to ensure they are at an acceptable level for scientific publication. The articles obviously still need to be reviewed, but we believe this additional checks will improve the standard of submissions in the long run. Now we also have more reviewers from Africa and are working continually to obtain even more.So despite the hardships of working both remotely and in a difficult situation, the journal has thrived. We trust that the journal will continue to develop into the future as we constantly work on innovations to improve the quality of the SAJP.Our best wishes for 2021 and stay safe and happy.Prof. Aimée StewartEditor-in-ChiefSouth African Journal of Physiotherapy.


The gap between the kidney transplant recipient list and the number of organs available for transplantation continues to grow. Kidneys from living donors are a major source of high-quality organs. However, they commonly have benign conditions such as cysts and benign tumors that present as operative challenges. This case presents a donor kidney that had a benign angiomyolipoma. The kidney was donated in a standard, minimally invasive fashion. The tumor was then removed on the back table and transplanted without an issue. Both donor and recipient enjoyed a speedy recovery with no significant complications. There is a large discrepancy between the number of organ donors and the number of patients on the kidney transplant list . As of DOccasionally, donors present with benign conditions that can seem prohibitive to donations. One example is angiomyolipomas (AML), which are benign tumors that can grow to large sizes. AML is only second to renal cell carcinoma in causing spontaneous retroperitoneal hemorrhage ,9. FortuA healthy 54-year-old female presented to donate a kidney to a family member and was evaluated according to our standard protocol. Her CT scan showed a 2.52 cm left lower pole exophytic AML Figure . Our teaThe donor kidney was removed in a standard hand-assisted laparoscopic donor nephrectomy procedure. During the operation, the tumor was easily seen and protected Figure . The kidThe recipient operation proceeded with a standard open technique. A right lower quadrant incision was performed, and the iliac artery and vein were anastomosed to the corresponding iliac vessels. Upon reperfusion, the kidney showed minimal to no signs of bleeding from the excision site. Postoperatively, the recipient had immediate function of the graft. The recipient showed no signs of bleeding or urine leaks. Creatinine clearance increased appropriately to 91 ml/min by day 5 post-transplantation. At two months post-transplantation, the recipient continues to enjoy excellent renal function and reports no complications. Flum and colleagues reported on the overall management of patients with AML tumors . The diaNiemi and Mandelbrot reported comprehensively on the utilization of medically complex patients for kidney donations and concluded that the use of complex patients as donors is worthwhile for recipients . There iPatients who present with small AML masses normally do not need intervention. However, should these patients choose to donate a kidney, leaving the benign AML mass puts the recipients at risk of bleeding or needing additional intervention. The natural history of AML after transplantation is unknown. The advantage of ex vivo excision is that all associated risks are managed and reduced in advance. This rationale is what led to our planned intervention. We had an excellent outcome where neither the donor nor recipient will need surveillance or follow-up in regard to AML.AML tumors are usually harmless, but can grow and hemorrhage spontaneously. The utilization of these kidneys after an ex vivo excision allows donors to help intended recipients receive very valuable organs. This also allows them not to worry about the benign tumor for their lifetime. On the recipient end, a large number of high-quality life years can be added. Removing the AML also allows recipients to not to worry about the risks of tumor-related complications.