As there is only limited data on the comparison with other 18F-labeled PSMA PET tracers, a comparative preclinical study between [18F]AlF-PSMA-11 and [18F]PSMA-1007 was conducted. Mice with varying PSMA expressing tumors  underwent two PET/CT scans with both [18F]AlF-PSMA-11 and [18F]PSMA-1007. Ten additional mice bearing C4-2 xenografts were subjected to ex vivo biodistribution with either [18F]AlF-PSMA-11 (n = 5) or [18F]PSMA-1007 (n = 5). Absolute SUVmean and SUVmax values were significantly higher for [18F]PSMA-1007 scans in both C4-2 tumors (p < 0.01) and 22Rv1 tumors (p < 0.01). In C4-2 xenograft bearing mice, the tumor-to-organ ratios did not significantly differ between [18F]AlF-PSMA-11 and [18F]PSMA-1007 for liver, muscle, blood and salivary glands (p > 0.05). However, in 22Rv1 xenograft bearing mice, all tumor-to-organ ratios were higher for [18F]AlF-PSMA-11 (p < 0.01). In healthy organs, [18F]PSMA-1007 uptake was higher in the liver, gallbladder, small intestines and glands. Biodistribution data confirmed the increased uptake in the heart, small intestines and liver with [18F]PSMA-1007. Absolute tumor uptake was higher with [18F]PSMA-1007 in all tumors. Tumor-to-organ ratios did not differ significantly in high PSMA expressing tumors, but were higher for [18F]AlF-PSMA-11 in low PSMA expressing tumors. Furthermore, [18F]PSMA-1007 showed higher uptake in healthy organs.A wide variety of  Further research showed PSMA to be an excellent target for molecular imaging of prostate carcinoma, which has led to a steep increase in the development of PSMA targeting tracers. Initially, PSMA monoclonal antibodies were introduced targeting either the intracellular domain (7E11 or Capromab Pendetide) or extracellular domain (J591) of PSMA3. However, monoclonal antibodies have several disadvantageous characteristics for diagnostic purposes, such as a slow tumor uptake and a long circulating half-life. Consequently, the focus of PSMA radiopharmaceutical development has shifted to the development of low molecular weight molecules. These PSMA inhibitors consist usually of a hydrophilic glutamate-urea based pharmacophore coupled to a lipophilic chelator, which target the extracellular zinc pocket and lipophilic pocket of the PSMA protein, respectively. The different affinity of these radiotracers for the PSMA target is determined by the variable amino acid linked to the Glu-urea group and the chelator. Finally, the PSMA inhibitors can be internalized into the cell via clathrin-coated pits5. [68 Ga]PSMA-11 was the first PSMA PET tracer that was widely applied for prostate cancer positron emission tomography/computed tomography (PET/CT) imaging. This PET tracer has demonstrated excellent overall performance in both initial staging (sensitivity of 0.74 (95% CI 0.51–0.89)) and specificity of 0.96 (95% CI 0.85–0.99)) and recurrent prostate cancer (PCa)  for PSA ≤ 2.0 ng/mL and 0.94  for PSA > 2.0 ng/mL)9. However, the cyclotron produced fluorine-18 has superior imaging characteristics, including a longer half-life (110 min vs 68 min), a lower positron energy (0.65 MeV vs 1.90 MeV) and a higher positron yield (97% vs 89%)10. Therefore, interest in 18F-labeled PSMA radiopharmaceuticals increased11. As a result, a wide variety of [18F]PSMA PET tracers were developed, each with its characteristic advantages and disadvantages in terms of availability, ease of synthesis, binding affinity, pitfalls and biodistribution patterns13. Out of the extensive pool of [18F]PSMA PET tracers, [18F]DCFPyL and [18F]PSMA-1007 are the most commonly used and their performance has been compared to [68Ga]PSMA-11. Studies suggested the non-inferiority of [18F]DCFPyL compared to [68 Ga]PSMA-1115, as well as a similar biodistribution pattern16. A comparative pilot study between [18F]PSMA-1007 and [68Ga]PSMA-11 showed that both tracers identified all dominant prostatic lesions, while [18F]PSMA-1007 detected some additional low-grade lesions17. A meta-analysis by Liu et al. reported a pooled sensitivity and specificity of 0.923 and 0.442 for PSA > 2 ng/mL and 0.832 and 0.277 for PSA ≤ 2 ng/mL, respectively18. These results were confirmed by an intra-individual comparative study by Hoberück et al.19. The authors reported the exchangeability of both tracers depending on the availability, but highlighted the increased incidence of non-specific bone findings with [18F]PSMA-1007. This finding corresponds to the results of a matched-pair comparison by Rauscher et al. which observed a considerably higher number of benign uptake foci with [18F]PSMA-1007  compared to [68Ga]PSMA-1120.The prostate specific membrane antigen (PSMA) is a type II transmembrane protein that is upregulated on prostate cancer cells68Ga]PSMA-11, [18F]AlF-PSMA-11 was developed. The evaluation in several clinical trials revealed a low radiation burden21, good inter-reader reliability22 and non-inferiority with [68Ga]PSMA-1123. However, limited data is available on the comparison of [18F]AlF-PSMA-11 with other 18F-PSMA PET tracers such as [18F]PSMA-100724. Therefore, the aim of this preclinical study was to compare [18F]AlF-PSMA-11 to an established 18F-PSMA PET tracer. For this purpose, [18F]PSMA-1007 was selected as a comparator because of its widely commercial availability25. This study includes the intra-individual comparison of mice bearing PCa xenografts with varying PSMA expression as well as an ex vivo biodistribution with [18F]AlF-PSMA-11 and [18F]PSMA-1007.Based on the binding motif of [18F]AlF-PSMA-11 was synthesized on a modified SynthraFCHOL synthesis module  as previously reported26. [18F]PSMA-1007 was synthesized on an IBA Synthera + platform  as described by Kramer et al.27 using a commercially available kit .[18F]AlF-PSMA-11 and > 95% for [18F]PSMA-1007. The molar activity (MA) was determined by high performance liquid chromatography  and a calibrated dose calibrator, and resulted in a median activity of 187.0 MBq/nmol (range 181.7 – 190.8 MBq/nmol) for [18F]AlF-PSMA-11 and 98.2 (range 83.6 – 312.7 MBq/nmol) for [18F]PSMA-1007 at the end-of-synthesis.The radiochemical purity was determined by thin layer chromatography ) using 3:1 v/v acetonitrile in water as mobile phase and resulted in > 96% for AlF-PSMA-11 and [18F]PSMA-1007 within a timeframe of 4 days (range 1–4 days). All mice were intravenously administered 9.09 ± 0.55 MBq [18F]AlF-PSMA-11 with a MA of 61.64 ± 15.83 MBq/nmol and 9.72 ± 0.67 MBq [18F]PSMA-1007 with a MA of 53.40 ± 16.44 MBq/nmol. One hour after tracer injection, static total-body PET/CT scans were performed for 15 min, followed by a CT scan for co-registration.All mice received two PET/CT scans with both [The PET images were acquired in list mode using a small animal PET scanner  with a spatial resolution of 0.85 mm and an axial field-of-view of 13 cm. All PET scans were reconstructed into a 192 × 192 × 384 matrix by an ordered subsets maximization expectation (OSEM) algorithm using 30 iterations and a voxel size of 400 × 400 × 400 µm. High-resolution CT images were acquired using a small animal CT scanner  and iteratively reconstructed with 200 µm voxel size.18F]AlF-PSMA-11 with a MA of 59.78 ± 11.61 MBq/nmol (n = 5) or 2.12 ± 0.11 MBq [18F]PSMA-1007 with a MA of 57.44 ± 12.31 MBq/nmol (n = 5). All mice were sacrificed at 1 h post injection (p.i.) and organs including the spleen, intestines, stomach, kidney, bladder, muscle, bone, liver, heart, lungs, brain and testes were removed and collected, as well as a blood sample. All tissues were weighted and measured using a gamma counter .Ten four-to-six-week-old male NOD/SCID mice  bearing C4-2 xenografts were subjected to ex vivo biodistribution. All mice received either 2.42 ± 0.09 MBq PSMA-1007, additional activity uptake was observed in the submandibular glands, intestines and gallbladder. The activity uptake in the glands seems to increase from high PSMA expression (C4-2) to no PSMA expression PC-3).C4-2 tumors (high PSMA expression) and 22Rv1 tumors (low PSMA expression) were clearly visible with both PSMA tracers, but uptake in the latter was less intense. No activity uptake was observed in PC-3 tumors. With both mean and SUVmax values in both C4-2 tumors (high PSMA expression) and 22Rv1 tumors (low PSMA expression) were significantly higher for [18F]PSMA-1007 scans (p < 0.01) (Table 18F]AlF-PSMA-11 and [18F]PSMA-1007 for ratios including TLRmean (liver) , TMRmean (muscle) , TBRmean (blood)  and TSGRmean    , TMRmean (muscle) , TBRmean (blood)  and TSGRmean  . Similar trends were found for maximum tumor-to-organ ratios  Fig. . Howevermean values in organs suggests an overall higher activity uptake of [18F]PSMA-1007 in background tissues  and the liver , although the absolute uptake in the liver was relatively low for both PSMA tracers. No statistically significant difference could be observed in the kidneys. All glands  demonstrated higher [18F]PSMA-1007 activity uptake compared to [18F]AlF-PSMA-11, as well as the activity in the heart (blood pool) . Increased uptake of [18F]PSMA-1007 was also observed in the intestines with mean SUVmax values of 1.40 ± 0.89 with a maximum SUVmax value up to 3.33. Finally, no statistically significant difference could be observed in bone (spine) for [18F]PSMA-1007 and [18F]AlF-PSMA-11 .Comparison of SUVues Fig. . Overall18F]PSMA-1007. Although the uptake in the brain is statistically significant, the absolute values are insignificantly small. Furthermore, no significant difference could be found in the bladder, blood, bone (sternum), large intestines, lungs, spleen, stomach and testes.The tracer uptake in healthy organs was more thoroughly investigated by ex vivo biodistribution. Values are presented as percentage injected dose normalized for the weight of the organs Table . Biodist34. Although most comparative studies have suggested the overall comparable performance of these PET tracers, there are other factors to consider. [18F]PSMA-1007 has a more complex synthesis route including a critical [18F]fluoride azeotropic drying step whereas the synthesis of [18F]AlF-PSMA-11 can be performed in aqueous conditions. Where the PSMA-11 precursor is widely available for purchasing and in-house implementation, [18F]PSMA-1007 is commercially available as cassettes25. Several preclinical comparative studies between [18F]AlF-PSMA-11 and [68Ga]PSMA-11 have been conducted36, but data on the comparison with other 18F-labeled PSMA PET tracers is rather limited.Currently, there are several PSMA targeting PET tracers used in clinical practice. Several comparative studies between PSMA PET tracers have been conducted18F]PSMA-1007 compared to [18F]AlF-PSMA-11, although the difference for the low PSMA expression 22Rv1 tumors is less pronounced. The reported uptake values of [18F]PSMA-1007 for C4-2 tumors (comparable PSMA expression compared to LNCaP37) seem to be in line with previously reported values by Soeda et al. for LNCaP tumors (SUVmean of 1.81 ± 0.57 and SUVmax of 5.4 ± 2.6 versus SUVmean of 2.59 ± 0.37 versus SUVmax of 5.5 ± 1.0 in this study)38.PET images of both C4-2 and 22Rv1 xenograft bearing mice showed higher absolute uptake values for [18F]PSMA-1007, the tumor-to organ ratios show no significant difference between both tracers in C4-2 tumors (high PSMA expression). Furthermore, the tumor-to-organ ratios for [18F]AlF-PSMA-11 were significantly higher in 22Rv1 tumors (low PSMA expression). This could be explained by the higher uptake of [18F]PSMA-1007 in healthy tissues such as the liver, heart, and glands as well as the less pronounced absolute difference in tumor uptake between both PSMA tracers in low PSMA expressing tumors. These results suggest that [18F]AlF-PSMA-11 can be useful for the detection of lesions in proximity to organs with higher [18F]PSMA-1007 uptake such as the gallbladder, liver, heart (blood pool) and small intestines. However, the reverse also applies for the bladder and kidneys, as [18F]AlF-PSMA-11 is primarily renally excreted. Prostate cancer tumors with a low PSMA expression have been shown to be a negative prognostic factor for overall survival. A study by Seifert et al. investigated the correlation between PSMA expression and overall survival in patients who underwent [177Lu]PSMA therapy. Patients with low PSMA expressing lesions were reported to have a shorter survival (7.9 months) compared to patients without low PSMA expressing lesions . Whether this can be attributed to reduced efficacy of [177Lu]PSMA therapy or to dedifferentiated and more aggressive tumor phenotypes, remains unclear39. Nevertheless, it remains important to detect the presence of low PSMA expressing metastases to aid in the prognostication and decision making process regarding treatment plan. The higher tumor-to-organ ratios for [18F]AlF-PSMA-11 compared to [18F]PSMA-1007 may therefore be beneficial for the detection of low PSMA expressing tumors. This will mostly depend on the location of the lesion, as the absolute tumor uptake remains higher with [18F]PSMA-1007. Furthermore, the detection of non-prostatic tumors is a potential application these are mostly characterized by a low PSMA expression40.Although the absolute uptake values were higher for [18F]AlF-PSMA-11, the absolute uptake values in the muscle are relatively low (0.13 ± 0.03 for [18F]PSMA-1007 compared to 0.07 ± 0.02 for [18F]AlF-PSMA-11), which renders this parameter clinically less relevant. Images in Fig. Although the tumor-to-muscle ratio seems to be significantly higher for [18F]AlF-PSMA-11 and 53.4 ± 16.4 MBq/nmol for [18F]PSMA-1007). Although [18F]PSMA-1007 has been reported to achieve molar activities up to 1000 MBq/nmol41, the study by Soeda et al. showed no significant difference in tumor uptake values between 1000 and 100 MBq/nmol. However, at these higher MA, the uptake in the salivary glands increased significantly38.As the molar activity has a large influence on the tumor uptake, both radiotracers were administered in comparable MA values . These results are consistent with the study by Soeda et al. who also reported increased uptake in the small intestines38. Overall, [18F]PSMA-1007 seems to accumulate more in healthy organs that express PSMA to a low extent . This might be caused by a higher affinity of [18F]PSMA-1007 compared to [68Ga]PSMA-1143, which has been shown to have a similar affinity to [18F]AlF-PSMA-1136. Although this probably leads to the superior tumor uptake, this also causes more aspecific uptake in non-tumor tissue, increasing the background activity. A matched-pair comparative study evaluating the frequency of benign uptake for [18F]PSMA-1007 and [68Ga]PSMA-11, suggested that five times more lesions (245 out of 369 PSMA-uptake positive lesions) could be attributed to a benign origin for [18F]PSMA-1007 compared to 52 of 178 PSMA-uptake positive lesions for [68Ga]PSMA-1120. This difference was attributed to either the higher affinity of [18F]PSMA-1007 and the superior spatial resolution of fluorine-18. An overview of the strengths and weaknesses of both radiotracers is given in Table Several organs were difficult to delineate on PET images. For example, the spleen is located too closely to the kidneys to be accurately delineated, and it is difficult to distinguish between the large and small intestine on imaging. Therefore, additional biodistribution data of healthy organs was collected. Although PET images demonstrated increased uptake in the bladder of [18F]PSMA-1007 (hepatobiliary clearance) and [18F]AlF-PSMA-11 (urinary clearance) is comparable between mice and humans.The major limitation to this study is the difference in PSMA expressing tissues between mice and humans. Because of the high PSMA expression in murine kidneys, it is possible that kidney activity in humans may give different results. However, imaging and biodistribution data concerning the bladder and liver suggests that the primary excretion pathway for [18F]AlF-PSMA-11 and [18F]PSMA-1007 demonstrated good image quality. High and low PSMA expressing tumors demonstrated higher absolute tumor uptake with [18F]PSMA-1007, but tumor-to-organ ratios did not differ significantly and were higher with [18F]AlF-PSMA-11 in low PSMA expressing xenograft bearing mice. This may be attributed to increased [18F]PSMA-1007 uptake in healthy organs such as the liver, heart and salivary glands but also in the gallbladder and small intestines. Whether these preclinical observations will result in clinically relevant differences between both radiotracers should be further investigated.Both [Supplementary Information.


S/D0, opening ratio D/D0, hole shape and arrangement of layers, were selected to check their effect on the buckling load and postbuckling behavior of the tested channel profiles. To carry out the numerical analysis, the Abaqus software was used. The results obtained during the analysis helped to identify the best combination of tested parameters to obtain the highest critical load. The performed analysis show that the columns’ behavior is sensitive to configuration of composite, opening ratio and hole shape.Open holes or cut-outs have been commonly used in composite structures for various engineering purposes. Those elements often demand perforation especially for weight reduction and to ease maintenance and servicing operations, for example, in aircraft wing ribs. This work presents a numerical study of the stability behavior of composite perforated columns subjected to a compressive load. Profiles were made of CFRP laminate and weakened by three types of cut-out. Four parameters, spacing ratio  Thin-walled structures belong to the load-carrying elements characterized by high stiffness and strength while maintaining low weight ,2,3,4 anThin-walled channel profiles are currently widely used and often weakened by holes to reduce their volume. An example of such elements are perforated profiles used, among others, for shelves, balustrades, etc. In In the literature, there are a lot of investigations about the design and behavior of columns with different kinds of cross-sections made of composite ,25,26 orThe load-bearing capacity of composite profiles, due to wide usage of composite elements in a thin plate form, is very important. Furthermore, different kinds of cut-outs are very often made as a part of the project. This makes the information about the buckling and postbuckling behavior of composite profiles weakened by holes necessary.The idea of this work is based on the study carried out by Khazaal et al. , who tesThis paper includes the linear and nonlinear analysis of compressed, thin-walled, perforated profiles with a channel cross-section. Numerical calculations were carried out with the commercial Abaqus program using the finite element method (FEM). The effect of parameters such as hole shapes, spacing ratio, opening ratio and arrangement of layers’ layout on the buckling and postbuckling behavior of the perforated channel cross-section profiles was investigated. Moreover, obtained results were compared with unperforated profiles which were tested in previous works ,35,36. IThe research subjects were thin-walled composite profiles with a C cross-section subjected to axial compression. The geometric parameters of tested profiles are shown in According to the previous research ,36,37, fThe results presented above became a reference point for the research performed and presented in this paper. The current paper focuses on the behavior of channel cross-section profiles weakened by holes and subjected to axial compression. This work does not concern the in-depth presentation of the experimental results, it focuses on the numerical analysis, but this is the start for further experimental research.D—width of profile web; D0—diameter/width of hole; S—distance between holes; D/D0—opening ratio; S/D0—spacing ratio.In this work, according to ,33, threFor composite profiles, this kind of Eurocode does not exist but it was a good reason to take those equations under consideration and perform numerical analysis for composite columns with a channel section. The above equations were used in  to analyD/D0), spacing ratio (S/D0) and hole shape, were taken under consideration, and their influence on buckling and postbuckling behavior was measured. The opening ratio (D/D0) and spacing ratio (S/D0) were selected according to Equations (1) and (2). Parameters which were outside the bounds of the above equations were also taken into consideration. The parameters and levels are presented in Three parameters, opening ratio  presents mathematical notation of the loss of stability phenomenon. The scope of numerical simulations involved describing the critical state of the structure and influence of shape and parameters of cut-outs on critical force.The second stage of analysis tackled the nonlinear stability problem, based on the incremental iterative Newton–Raphson method. This analysis allowed us to determine the equilibrium path for the structure. The calculations were performed until failure initiation of first layer according to the Tsai–Wu criterion .The discrete model was prepared by using 8-node shell elements (S8R) of second order with reduced integration. The structure of the composite material was defined depending the thickness of the finite element. Mesh density, which was used for the composite profiles, equaled 4 mm and was selected as the optimal density according to the previous analyses on unperforated profiles with channel cross-sections . The valZ-axis (compressive force direction) and the lower plate was fully fixed. The boundary conditions were defined in a created reference point (RP), connected to plates. Between the plates and composite profile, a contact interaction was introduced with a friction coefficient of 0.2.The boundary conditions of the tested model are presented in In this section, the results from the performed numerical analysis are presented. The presented results from FE analysis show that the introduction of perforation leads to the load decrease. The circular holes caused a smaller decrease of critical load and for all tested cases it was in the range of 17 ÷ 28.48%. For square holes, this range was 21.30 ÷ 35.06% and for the hexagonal holes it was 18.76 ÷ 31.54%. It can be observed that when increasing the opening ratio, the buckling load also increased a, whereaD/D0 = 2 and with spacing ratio S/D0 = 1.67. In [It can be observed that among all tested samples with different kinds of hole shapes, the circular holes had the greatest impact on the buckling load with opening ratio 1.67. In , the bes1.67. In  the bestIn this section, the results of the lay-up effect on the buckling behavior of the tested profiles are presented. It can be observed that the laminate lay-up has a significant effect on buckling load. Furthermore, the weakest configuration is P4 and the difference between buckling load for unperforated and perforated profiles for this configuration is more than 20%, compared to the other three configurations where the difference was less than 20%. The highest critical load was obtained for the P2 lay-up. This is ascribable to the fact that, for P2, most outer layers are at an angle of 45 degrees, whereas for P4 the lay-up consists of a few layers at an angle of 90 degrees, which reduces the overall structural stiffness. In all cases, the shape of the buckling mode maintained its symmetrical character with respect to the symmetry plane of the C-profile . HoweverThe place of maximum deformation was also different: for the P1 and P2 configurations, it was on the shelf closest to the rigid plate and for the P3 and P4 configuration it was in the middle of the profile shelf.In the second part of the research, the nonlinear stability of the structure in the postbuckling range was measured. The aim of the analysis was to investigate the profile behavior in the postcritical state with the implemented lower buckling mode, which was determined in the first part of the tests. During the loading of the structure, a deepening form of laminate buckling was observed. The load-carrying capacity of tested profiles was determined by the Tsai–Wu failure criterion. This criterion was successfully used to determine the failure load of a compressed thin-walled composite plate element weakened by holes and columns with complex cross-sectional shapes in ,43,44. FIt can be observed that the most critical area is the corner near to the end of the cross-section. Moreover, the introduction of perforation did not change this localization. The obtained results show that for all of the tested profiles, the postbuckling equilibrium paths are stable. In addition, the postbuckling behavior of perforated and unperforated profiles is similar at the beginning. However, with the deepening of the deflection, the differences between the equilibrium paths increase. The highest deflection at failure was observed for the P4 lay-up and the lowest one for the P2 lay-up. Furthermore, the equilibrium path for the P2 laminate lay-up seems to be the one with the highest stiffness.D/D0, the spacing ratio S/D0 and composite arrangement of layout on buckling behavior of perforated profiles was studied. The obtained results were compared with profiles without holes. On the basis of the obtained results, some conclusions can be drawn:➢The introduction of perforations caused a decrease in the buckling loads: 21.30 ÷ 35.06% for the square shape, 17 ÷ 28.48% for the circular shape and 18.76 ÷ 31.54% for the hexagonal shape.➢The obtained results show that the shape of holes, opening ratio and arrangement of laminate layers have the greatest impact on the value of buckling load, whereas the spacing ratio has no significant influence on the buckling load.➢D/D0 = 2 and S/D0 = 1.67 gave the highest value of critical force.The circular holes with ➢The highest critical load was obtained for the P2 lay-up, while the lowest one for the P4 lay-up.➢The introduced perforation caused not only a decrease in the critical load value, but also a change in the buckling form. The decrease in the critical load for all tested configurations was: 17.4% for P1, 15.27% for P2, 18.08% for P3 and 29.32% for P4.In this study, the linear and nonlinear analysis of perforated composite profiles with a C cross-section subjected to axial compression was performed. The effect of three hole shapes, opening ratio The presented results allow us to expand our knowledge about the design of thin-walled composite structures weakened by holes with potential significance for practical applications. However, to confirm the obtained numerical results, a deeper analysis of nonlinear stability conditions and experimental validation are necessary.


This study aimed primarily to investigate the lateral batting backlift technique (LBBT) among semi-professional, professional and current international cricket players. A key question was to investigate whether this technique is a factor that contributes to success for cricket players at the highest levels of the game.The participants in this study’s sample (n = 130) were South African semi-professional players (SP) (n = 69), professional players (PP) (n = 49) and South African international professional players (SAI) (n = 12). Biomechanical and video analyses were performed on all the participating groups. Classifiers were utilised to identify the batting backlift technique type (BBTT) employed by all batsmen. All statistics and wagon wheels (scoring areas of the batsmen on a cricket field) were sourced online. A Pearson’s Chi-squared test, Student T-test, one-way analysis of variance and T-test were performed in this study. All analyses were performed using R (R Core Team) at a significance level of α = 0.05.This study found that a LBBT is more common at the highest levels of batsmanship with batsmen at the various levels of cricket having percentages of the LBBT as follows: SP = 37%; PP = 38%; SAI = 75%; p = 0.001. There was also a noticeably higher difference in the highest scores and career averages between all groups of players, as well as batsmen who either use a straight batting backlift technique (SBBT) or a LBBT. This study also found that SAI batsmen who used the LBBT were more proficient at scoring runs in various areas around the cricket field .This study found that a LBBT is a contributing factor for success regarding players wanting to play cricket at the highest levels. Cricket coaches should also pay attention to the direction of the backlift with players, especially when correlating it to various scoring areas on the cricket field. Further in-depth research is required to fully investigate the change in batting backlift techniques among cricket players over a long-term period. Qualitative biomechanical analyses of movement in sports are key to its investigation. Such a mode of investigation can provide important insights into the biomechanics of technique in sports. Cricket batting is complex with different variables such as the grip, stance, initial movement, backlift, downswing and follow through. An important component of the overall batting technique is the backlift, a technical component of batting that has defied the traditional attempt to constrain its motion to the linear plane.,5 The most proficient run-scorers of the game lift the bat from the region of the slips, often causing the downswing path of the bat to deviate from its upswing. Devising a qualitative biomechanics model of the backlift could therefore do much to probe its underlying mechanics.The mechanics of the backlift in cricket batting are poorly understood. This is contrary to what may be logically expected as the most effective means of preparing for a straight and efficient downswing.,7 It was also found that angling of the backlift away from the body was common, and was similar for all skilled and lesser-skilled batters. It has been proposed that this angle may provide a comfortable position for the batters to place their hands in preparation for the subsequent downswing, allowing for a possible more ‘rotary’ movement of the wrists by which the bat’s backswing and downswing can be performed in a continuous motion.Examinations of the backlift of the bat provide an interesting insight into how skilled batters achieve control of the bat to effectively and efficiently swing their arms to successfully strike a ball. Many batters have been observed to adopt a backlift that is diverted away from their body, rather than positioning their bat directly behind them as is commonly advocated in the coaching literature. on international batsmen (n = 9) was one of few studies that demonstrated findings of the backlift in cricket batting. The study showed that path tracings of the bat indicated a distinctive loop, which was unexpected. There was no clear evidence provided by the authors to explain the cause of this significant loop, aside from the fact that a greater diversity of strokes would be a possible outcome as batsmen would get used to hitting the ball in this way. In addition, it was found that the path of the bat deviated laterally from the mean alignment of the shoulders, reaching an average maximum angle in the transverse plane of 47° (after the batsmen initiated the backlift). The study then indicated how this angle was reduced by a mean of 23° at the top of the backlift, which showed that the position of the bat was increasingly lateral from an alignment that would enable the required bat plane to drive to the offside. Stuelcken et al. also proposed that batsmen manoeuver their bat by using their wrists as levers to position the bat close to the body’s centre of mass. This may help to keep the bat’s centre of mass close to the batter’s base of support, and ultimately allow a later downswing, thereby helping to overcome the temporal constraints inherent in batting. If the wrists were to be moved away from the body in the bat’s backswing, more energy and time would be required to produce the backswing and downswing respectively.,8 If the wrists are kept close to the body, the batter is afforded a mechanical advantage as the moment of inertia required to move the bat at a given velocity is reduced. This decreases the amount of muscular effort required to play a stroke, allowing the bat to travel through a smaller arc to enable its faster movements.,8Research conducted in Australia by Stuelcken et al.  followed on from the above study which had shown that a vast majority of successful batsmen (77%) in the last century had used a lateral batting backlift technique (LBBT). It was also investigated that the LBBT is a key contributing factor to the success of the overall cricket batting technique. The LBBT is one in which the bat is lifted laterally in the direction of second slip or gully. Therefore, the face of the bat is directed towards point or the offside. By contrast, the backlift, where the bat is lifted towards the stumps or first slip and the face of the bat points towards the wicket-keeper or the ground, is known as the straight batting backlift technique (SBBT).Recently, Noorbhai and Noakes For example, Sir Donald Bradman  exhibited a highly unique ‘rotary’ technique, which is contrary to coaching conventions, and is yet to be replicated.,9 In modern coaching manuals (those published after 2009), it has become an acceptable norm for batsmen to lift the bat in the direction of the slips. A mixed-methods study conducted among 161 coaches around the world showed that most of them (83%) coach the SBBT technique as opposed to the LBBT at various proficiency levels of the game. With regards to the higher levels of cricket, most coaches understand the potential value of the LBBT but have challenges coaching it. Expert coaches have frequently supported the notion that there is no necessarily ‘right’ or ‘wrong’ way to bat, and that many of the greatest players have exhibited techniques not necessarily commensurate with those recommended in coaching manuals., this present study attempts to investigate the batting backlift technique (BBT) among semi-professional, professional and current international cricket players. The findings of the previous study suggested that the LBBT is a likely contributing factor to effective batsmanship. Therefore, a key question in this present study was to investigate to what extent batters at the lower levels of the game use the LBBT. These authors’ hypothesis suggests that the LBBT acts as a selective factor among proficient batters at the highest levels of cricket.As a previous study by these authors had analysed successful batsmen only at the highest international level Since the backlift direction can be readily detected with qualitative observations from the direction in which the toe of the bat is pointing, and since there are additional gaps to explore regarding the LBBT as highlighted above, these authors considered it feasible to investigate the following question: is a LBBT used more frequently by batters at the highest levels of the game, compared to batters at lower levels?As previously mentioned, the authors hypothesised that the LBBT is a contributing factor for cricket players wanting to play cricket at the highest levels of the game.This was a cross-sectional research study in which analytical and qualitative biomechanical research methods were employed.Ethical approval for the study was granted by the Human Research Ethics Committee of the University of Cape Town (HREC: 586/2014). All participants provided signed consent prior to participating in the study. This study conforms to the World Medical Association Declaration of Helsinki on Ethical Principles for Research Involving Human Subjects.Participants (n = 130) were South African semi-professional players (SP) (n = 69), professional players (PP) (n = 49)  and SoutVarious types of deliveries  were analysed from the SP and PP when they faced a fast, fast-medium or spin bowler. Any deliveries that were determined as wide, no-ball or a full toss were excluded from this analysis. Participants were required to bat using their usual batting technique in either a match or practice situation. For the SAI group, the deliveries were randomly chosen. Similarly, any deliveries that were determined as wide, no-ball or a full toss were also excluded from this analysis.The researchers had considered the use of the bowling machine to ensure standardisation during the study. However, the objective of the study was to mimic a match situation (through practices in the nets or match practices) and an environment where various players had bowled to the batsmen. Legitimate deliveries by the bowlers were not permutated, allowing for the measures and responses from the batsmen to be consistent and accurate. All six deliveries per batsman were analysed and the still frame that best represented the player based on how the various deliveries were faced. The batsmen were used in the figure descriptions to determine the backlift type.http://www.youtube.com), since it was challenging to recruit the South African international cricket team while they were on tour overseas.For the SAI players, video footage was obtained via YouTube  software package, in conjunction with a virtual protractor to ensure further reliability of the angle ranges. The analyses were done similarly to those in other studies,8 whereby the initial movement of the batsman was determined from the first frame before the initiation of the backlift, while initial movement patterns were assessed qualitatively by viewing the footage. The backlift represented the period from the initiation of the backlift to the maximum vertical displacement of the toe of the bat. The video frame was also selected immediately before the bowler released the ball. These frames were then used to determine the type of batting backlift technique for each type of delivery bowled. Variables of interest included the direction of the backlift and the direction of the face of the bat during the backlift from a Canon LEGRIA HF R506 HD CamcorderTM video camera attached to a laptop computer. An external hard drive from the video camera was inserted into the laptop for further usage of the software. The frontal camera was situated 20 m away from the participants (for the SP and PP only) and in the line of where the bowler released the ball, just behind the bowler facing the batsman , 2 (bat face facing first or second slip), and 3 (bat face towards gully or point). If the bat is directed fairly straight back or towards the slips/gully regions but has an open face, it is classified as classifier 3. Angle ranges were conceptualised to determine these classifiers (1: between 0° – 25°), (2: between 25° – 45°), (3: between 45° – 80°). This strengthens the validity and reliability of the analysis as the backlift can be readily detected and analysed at different positions and time points in the backlift. Drawing a vector is a common approach in defining the toe of the bat and how it will point in a particular direction. Lines and vectors were drawn (1) vertically from the head to the hands (green line), (2) a line drawn horizontally to show where the hands rest (blue line), and (3) a line drawn obliquely to show the direction of the bat during the backlift (red line)  . The linhttp://www.espncricinfo.com) was used to retrieve the career statistics of each player . South African domestic players’ statistics were also sourced from their first-class (three- or four-day games) and List A (one-day games) results.Cricinfo  and PP  were used to analyse the batting backlift technique of the players. at a significance level of α = 0.05.A Pearson’s Chi-squared test was performed to determine whether percentages of batsmen using a LBBT differed between the levels of professional cricket. The Student’s T-test was used to compare highest scores, career averages and strike rates between batsmen with a LBBT and SBBT, and batsmen in each population group , respectively. For SAI, just T-tests could be performed for test matches as only a single batsman using a SBBT had scored in ODI matches and the means for this group could be calculated. A one-way analysis of variance (ANOVA) was also calculated for highest scores, career averages and strike rates for first-class cricketers and List A statistics. All analyses were performed using R2 = 39.02, df =3, p = 0.001).In this study, 37% of SP and 38% of PP used a LBBT respectively (p>0.05)  and 2. AF  = 19.369, p = .000 and List A cricket, F  = 18.85, p = .000 (t(103) = −3.18, p = .000 and List A cricket, t(102) = −3.61, p = .000. The high scores of cricketers at the amateur level was significantly different from the international level for both first class, t(64) = −6.32, p = .000 and List A cricket, t(27) = −8.21, p = .000. Similarly, high scores of cricketers at the franchise level was significantly different from the international level for both first class cricket, t(61) = 3.87, p = .000 and List A cricket, t(28) = −4.88, p = .000   .F = 10.89, p = .000 and List A cricket, F = 14.31, p = .000 (t(103) = 1.78, p = .038 and List A cricket, t(103) = 2.64, p = .005. The averages of cricketers at the amateur level were significantly different from the international level for both first-class cricket, t(36) = −7.75, p = .000 and List A cricket, t(31) = −7.75, p = .000. Similarly, career averages of cricketers at the franchise level were significantly different from the international level for both first-class cricket, t(46) = −5.93, p = .000 and List A cricket, t(31) = −5.22, p = .000   and career averages , and for List A cricket among highest scores  and career averages   . When co= 0.001) .As expected, there were no significant differences for all analyses on strike rates.For test matches, the average highest score for South African International batsmen using a LBBT was significantly higher than that for batsmen using a SBBT  . HoweverThe main finding of this study has shown that a LBBT is commonly used by batsmen at the highest levels of cricket. Despite the small differences in percentages of SP and PP using the LBBT, this finding is nevertheless compatible with the interpretation in this study that the LBBT is more common at the highest levels of cricket .There were also noticeably higher differences in the highest scores and career averages between all groups of players, as well as batsmen who either use a SBBT or a LBBT. As such, the LBBT acts as a selective factor among proficient batters at the highest levels of cricket batting.This study has shown that the analysis of high scores and career averages was significant for both first-class cricket and List A cricket. Comparisons indicated that the high scores and career averages of cricketers at the amateur level were significantly different from the franchise level for first-class cricket and List A cricket. The high scores and career averages of cricketers at the amateur level were significantly different from the international level for both first-class and List A cricket. Similarly, high scores and career averages of cricketers at the franchise level were significantly different from the international level for first-class cricket and List A cricket.This shows how performances (in the form of career averages and highest scores) increases with players who use the LBBT at the higher levels of the game in both limited overs and four-day cricket.Wagon wheels were only available for the SAI groups, and therefore scoring areas and career statistics of these players will be clarified.The SAI batsmen’s wagon wheels show interesting findings. Batsmen with a LBBT were found to score runs in more areas around the cricket field and in front of the wicket. By contrast, batsmen with a SBBT scored runs in selected areas around the cricket field only and roughly in front of the wicket (mostly behind square with shots such as the late cut and leg glance). Although the late cut to third man and leg glance to fine leg can be rewarding for batsmen, these are not shots that are always commonly played by batsmen within an innings. Some batsmen who are more defensive in their approach would score runs in selected areas around the cricket field whereas more aggressive batsmen may score runs in various parts of the cricket field. Interestingly, wagon wheel examples of three left-handed SAI batsmen with a LBBT   show thaIn addition to the SAI batsmen’s scoring areas, it is also worth noting their productive shots used during their highest scoring innings in either a test match or ODI. Batsmen with a LBBT (n = 9) had a leg glance and pull as their most productive shot (the leg-side), whereas batsmen with a SBBT (n = 3) had a cover drive as their most productive shot (off-side). From this, it is suggested that batsmen with a LBBT are more likely to go at a ball harder in the high scoring zone (on the leg-side) as opposed to a less high scoring zone (on the off-side). In this instance, batsmen who had a LBBT mostly used the leg glance and pull (leg-side), implying that these are not straight bat shots whereas batsmen with a SBBT mostly played a cover drive, implying a straight bat shot.It is also important to consider the varied formats of the game. Batsmen would be more aggressive in one-day games as opposed to test matches. Further research is required in this area if there are variances in the batting backlift techniques of the same batsmen in all three formats of the game .Apart from Farhaan Behardien, three SAI batsmen with a SBBT were found to have the lowest high scores. Although an individual high score may not be an indicator for success, the observed pattern does support the idea that batsmen with a LBBT might be able to score runs more rapidly than batsmen with a SBBT. Furthermore, these three batsmen are part of the five batsmen from the SAI cohort that have the lowest strike rate in either tests or ODIs. Although the strike rate statistic is more pertinent in the ODI format of the game, it still raises the question of whether batsmen with a LBBT are able to score runs more rapidly than batsmen with a SBBT. It has also been shown that coaching with the SBBT may be detrimental to cricketers’ future prospects, as this study has shown that the LBBT produces better performances at the higher levels. In addition, if such players are not coached traditionally, they automatically hit the ball using the LBBT.The use of the LBBT may have decreased among a number of players as a result of exposure to traditional coaching methods and philosophies earlier in their careers.The strengths of this study are as follows:The ability to retrieve both completed batting records and video footage of all batsmen in this study.The sample number of 130 batsmen  is reflective of over half of the population sample of semi-professional and professional cricketers in South Africa.The analysis of all the six South African franchise teams (n = 49 batsmen) and nine out of the 13 South African semi-professional teams (n = 69).Each group of participants played in the same environment and in the same month, which limited a seasonal effect.Biomechanical and video analyses of players was also obtained objectively and was not self-reported.With regards to the limitations:Only wagon wheels of the SAI could be sourced. However, this sample was sufficient to correlate the runs scored on the field with the players’ BBT.The dots per inch (dpi) quality for some of the videos with the SP and PP appeared to be inconsistent due to the variances in weather when testing, as well as varied camera distances behind the bowler.The researchers accounted for perspective error by limiting the type of videos observed and including horizontal lines in the background.Exact angles were not measured, while it was only possible to measure and report on angle ranges. This was because the analysis was conducted in a field setting (due to the number of players studied) and not in a laboratory.,15 A LBBT may not come naturally to some professional players. Coaches should also pay attention to the direction of the backlift with players, especially when correlating the backlift to various scoring areas on the cricket field. At semi-professional and professional levels, a coach can only do so much to ensure optimal performance and subtle technical optimisations.All batsmen are unique in their technique and approach and will display attributes that are distinctive and suit them best as individual players. As scientists and coaches, the above should be taken into consideration in order to assist players with subtle discrepancies that may hinder their performance. Innovative coaching tools , in the form of a coaching cricket bat and a mobile application, are also available for coaches and players to improve and assist with the coaching of the LBBT.This study found that a LBBT is more common at the highest levels of cricket batsmanship. Batsmen at the various levels of cricket had percentages of the LBBT as follows: SP = 37%; PP = 38%; SAI = 75%; p = 0.001. The LBBT is a contributing factor for cricket players wanting to play cricket at the highest levels of the game. This study showed that there was also noticeable difference in the highest scores and career averages between all groups of players in general as well as batsmen who either use a SBBT or a LBBT. Cricket coaches need to pay attention to the direction of the backlift with players, especially when correlating the backlift to various scoring areas on the cricket field. Further in-depth research is required to fully investigate the change in batting backlift techniques among cricket players over a long-term period.


The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity. The global market for the production and industrial applications of biopolymers is constantly developing owing to the high consumer demand. The application of biodegradable and environmentally friendly materials has a positive influence on the right balance of waste management. In recent years, biocomposites are increasingly used in various sectors of the economy, particularly in the rubber industry.Conventional rubber fillers are organic or inorganic substances, that are introduced to the elastomer matrix to improve mechanical, thermal, chemical, dielectric or processing properties of rubber composites and to reduce production costs by increasing the weight and volume of the final rubber product . The mos2, water, methane and other products with low molecular weight, can be absorbed back into the earth [According to European Bioplastics, a plastic material is defined as a bioplastic if it is either biodegradable or biobased or features both properties. Biocomposites are biobased materials and have no harmful effect on the environment; their disposal results in less air pollution and global warming . During he earth . Technolhe earth ,7,8,9. H6H10O5)n. It has a granular form and consists mainly of two types of polysaccharides: amylopectin and amylose, with different structures and functions. There are also limited amounts of lipids proteins and minerals [Starch is common in nature and can be obtained from cereals , roots or tubers (potatoes and cassava) and sugar, fruits and vegetables . The staminerals . Starch minerals ,13,14. Hminerals . Therefominerals , applicaminerals  or starcminerals ,18.In the last decade, ionic liquids (ILs) have gained more interest as solvents for polysaccharides, including starches ,20. The Walnut shells are one of the agricultural biomass waste materials sourced from the walnut dry fruit . WalnutsIn order to improve the polymer–filler interactions, and thus the performance of vulcanizates, many modifications are used, including treatment of the filler surface with coupling agent prior to incorporation to the polymer matrix or adding a coupling agent directly to the composite. Moreover, most elastomers are nonpolar, whereas in many cases biofillers are hydrophilic. Silanes are widely known additives, used for improving the interfacial adhesion and compatibility between fillers and elastomers . HoweverIn this work, we applied corn starch and ground walnut shells as biofillers of NR elastomer biocomposites. Studies have been performed to prove that these biofillers can be successfully used as inactive fillers alternative to chalk or talc. Additionally, ionic liquid BmiCl and aminosilane such as (3-aminopropyl)-triethoxysilane (APTES) were applied to enhance the vulcanization process of NR compounds and to improve the compatibility between NR elastomer and biofillers tested and thus the useful properties of NR vulcanizates. Furthermore, the influence of the amount of biofiller used on the properties of NR composites was explored. Biobased materials have been repeatedly reported as not improving the properties of polymer composites ; thus, wThe rheometric properties of NR compounds were investigated to determine the effect of the content and the type of biofiller used as well as APTES and BmiCl on the curing parameters. The rheometric measurements were performed at 160 °C and the results are summarized in min) is a measure of the viscosity of the uncrosslinked rubber compound. The value of Smin for the unfilled NR compound was 0.5 dNm. Considering the measurement error, addition of biofillers and both APTES and BmiCl did not significantly affect the Smin value and therefore the viscosity of NR biocomposites (The minimum rheometric torque (Smposites . This ismax) depends on the crosslinking degree of the elastomer. It is also affected by the hydrodynamic effect of the filler used. The unfilled NR compound showed Smax value of 5.4 dNm. Based on the obtained results, it was concluded that the type of biofiller used had no significant influence on the Smax values. NR compounds filled with starch, especially those containing 20 phr of this bioadditive, showed higher Smax compared to unfilled NR, which was directly related to the increase in the stiffness of the composition [max of approximately 1 dNm. Regardless of the biofiller’s amount, NR compounds containing walnut shells exhibited slightly higher Smax compared to the unfilled NR and similar to that of the rubber compound filled with 10 phr of starch. The highest Smax was observed for NR compounds containing APTES and BmiCl, especially those filled with starch. In our previous work [max of NR compounds. The positive influence of APTES and BmiCl on the Smax could result from both the improved compatibility of the biofillers used with NR matrix and the increased crosslinking degree of the elastomer.The maximum torque  and 2.4 dNm  higher ∆S compared to the unfilled benchmark. It was probably due to the improved polymer–biofiller compatibility after introducing BmiCl and beneficial influence of BmiCl on the crosslinking degree of elastomer. It should be noticed that NR compounds containing APTES were also characterized by the higher ∆S compared to the unfilled benchmark and rubber compounds without this additive. However, the improvement of ∆S resulting from APTES addition was slightly smaller as compared to the BmiCl.The rheometric torque increase (∆S) results from the increase in the stiffness of rubber composite during rheometric measurement; thus, it can be considered as a measure of the crosslinking degree of elastomer. In the case of rubber compounds containing fillers, ∆S is also affected by the hydrodynamic effect of the filler used. Regarding the examined NR compounds, the influence of the filler, APTES and BmiCl on ∆S fully correlated with their effect on the values of S02) defines the safety of the processing of rubber composites at a certain temperature. The longer the t02, the more secure the processing; thus, the rubber compound can be processed without the risk of scorching. The unfilled rubber compound exhibited a t02 of 2 min, whereas the scorch time for the NR compounds filled with starch and walnut shells was extended by approximately 1 min, thus resulting in the slightly improved safety of the processing. In contrast, APTES and BmiCl reduced the t02 of the filled NR compounds to 1 min.The scorch time (t90) is a crucial parameter from a technological and economic point of view. In the industry, shorter vulcanization times are more desirable because of the reduction of the total cost of final rubber products by reducing the cost of the rubber compound’s vulcanization. The unfilled rubber compound exhibited the t90 of 7 min. Rubber compounds filled with starch or walnut shells demonstrated t90 to be approximately 2–3 min shorter compared to the unfilled benchmark. Therefore, the accelerating effect of starch and walnut shells on vulcanization was observed. The accelerating influence of starch on the vulcanization of NR was reported by Riyajan et al. [90 by about 4 min as compared to the benchmark. Hence, APTES and BmiCl shortened both t02 and t90 of rubber compounds, which proves their accelerating effect on vulcanization. The beneficial influence of silane on the vulcanization was confirmed by other researchers [The optimal vulcanization time  of NR vulcanizates filled with both starch and walnut shells was greater compared to the unfilled sample  of the NR elastomer was determined as well. The results of DSC analysis are summarized in In the next step of the research, differential scanning calorimetry (DSC) was employed to explore the influence of biofillers and other additives, i.e., silane and BmiCl, on the crosslinking temperature and the enthalpy of crosslinking reactions. The influence of biofillers APTES and BmiCl on the glass transition temperature (Tp) presented in g of NR determined for the unfilled benchmark was approximately −62 °C, so typical for NR [g of the elastomer.Analyzing the differential scanning calorimetry (DSC) results, the change in the heat capacity  compared to the unfilled vulcanizate. In contrast, vulcanizates containing APTES and BmiCl exhibited slightly higher SE300 compared to the unfilled benchmark and vulcanizates without these additives. It resulted from the higher crosslink density of these vulcanizates compared to other samples. It is commonly known that SE300 depends strongly on the crosslink density of vulcanizates and increases when the crosslink density increases [Analyzing the data collected in ncreases .Regarding the tensile strength (TS) and elongation at break (EB) of vulcanizates, the unfilled benchmark reached the TS value of 10.4 MPa and EB of approximately 820%. Vulcanizates filled with starch showed slightly improved TS compared to the unfilled benchmark. The amount of starch had no considerable influence on the TS of the vulcanizates. The starch-filled vulcanizate without BmiCl and APTES exhibited approximately 1.3–1.7 MPa higher TS than the unfilled sample, whereas TS of the vulcanizates containing BmiCl and APTES was approximately 1 MPa higher than that of the unfilled NR composite . Regardless of their amount, application of walnut shells did not significantly affect the TS of vulcanizates compared to the unfilled benchmark. APTES and BmiCl did not improve the TS of the NR vulcanizates containing walnut shells.The elongation at break (EB) is a parameter strongly dependent on the crosslink density and filler’s addition. Introducing the biofillers, APTES and BmiCl to NR composites reduced the EB by approximately 200–300% as compared to the unfilled benchmark. Moreover, vulcanizates containing BmiCl showed the lowest EB of all tested vulcanizates . This resulted from the highest crosslink density of these vulcanizates.It is known that the hardness is directly proportional to the crosslink density of the vulcanizates and depends on the addition and activity of the filler. Considering the examined vulcanizates, the type of biofiller slightly affected their hardness. As expected, the unfilled benchmark exhibited the lowest hardness of 31 Shore A. Introduction of starch and walnut shells slightly enhanced the hardness of NR vulcanizates compared to the unfilled sample (by 1–3 Shore A). Addition of APTES and BmiCl caused a further increase in the hardness of NR vulcanizates filled with starch, which was due to the higher crosslink density of those vulcanizates as compared to vulcanizates without these additives. In contrast, APTES and BmiCl did not considerably influence the hardness of NR vulcanizates filled with walnut shells.Taking into account the effect of starch and walnut shells on the tensile properties and hardness of NR vulcanizates, these biofillers can be classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk and talc . ApplyinDynamic mechanical analysis (DMA) was employed to study the influence of biofillers, APTES and BmiCl on the viscoelastic properties of NR composites and their ability to dampen vibrations. The measurements were performed as a function of temperature. The results are summarized in g) of NR elastomer determined in dynamic conditions (oscillating stretching). The Tg of NR determined by DMA for the unfilled sample was −68 °C, whereas the Tg for the vulcanizates filled with starch and walnut shells was approximately 1–2 °C lower. Therefore, the type and the content of biofiller as well as the additives used did not considerably affect the Tg of NR composites, which was within the measurement error.The DMA curves of NR vulcanizates filled with starch and walnut shells plotted in g  is a measure of the energy dissipated as heat by the elastomer network during each deformation cycle. By definition, tan δ is the ratio of the loss and the storage moduli (E”/E’) and corresponds to the material’s ability to dampen vibrations ,64. As eg  was exhi fillers ,66.Concerning the tan δ at 25 °C and 50 °C, i.e., in the rubbery elastic region , additioIt is known that NR composites have poor resistance to thermo-oxidative aging as compared to most synthetic rubbers . It has As expected, vulcanizates containing starch and walnut shells exhibited higher crosslink densities after prolonged exposure to 70 °C a. A simi300 depends on the crosslink density, NR vulcanizates demonstrated higher SE300 upon thermo-oxidation as compared to the nonaged samples . It was calculated using the changes in the TS and EB of vulcanizates resulted from the aging process. The results are summarized in Having examined the effect of thermo-oxidative aging on the tensile properties of NR vulcanizates containing biofillers, we then determined their aging factor . It resulted from significant negative changes in the TS and EB of the vulcanizates due to the aging process. NR elastomer contains double bonds, which are an active sites for oxidation reactions, leading to the polymer degradation [The unfilled NR vulcanizate showed poor resistance to thermo-oxidative degradation processes , since t1 Af = 0.. It resuf of the starch-filled composites was approximately 0.6, so the same as for the unfilled sample. Thus, the vulcanizates filled with starch were susceptible to thermo-oxidative aging similarly to the unfilled NR. Vulcanizates filled with walnut shells exhibited better resistance to prolonged thermo-oxidation compared to the unfilled benchmark and vulcanizates containing starch (Af of approximately 0.8). It is known that lignin can act as stabilizer in reactions induced by oxygen and its radical species due to the presence of hindered phenolic groups, thus improving the resistance of polymers to thermo-oxidation [f of the starch-filled vulcanizates. The beneficial effect of ionic liquids on the aging resistance of different elastomers has already been reported by various researchers [The application of biofillers did not significantly affect the resistance of NR vulcanizates to thermo-oxidative aging. The Axidation ,75. The earchers ,56,76.Thermal stability of elastomer composites strongly depends on the type and the amount of filler used, especially when biofillers are applied, which contain organic compounds. No less important are other organic additives, i.e., silane and ionic liquid, which decompose when heated to high temperatures.5%) was established as the temperature at 5% mass loss in relation to the initial mass of the biofiller. TG and derivative thermogravimetric (DTG) curves for pure biofillers are presented in In the first step of the research, thermogravimetric analysis (TG) was employed to determine the thermal stability of pure biofillers. The onset decomposition temperature  of the NR vulcanizates, which was reduced as compared to the unfilled vulcanizate. In contrast, no influence of biofillers and additives on the TDTG, and therefore, the temperature of the maximum mass loss rate was achieved. TDTG of the studied vulcanizates ranged from 399 °C to 401 °C. Thermal decomposition of the unfilled vulcanizate started at a temperature of approximately 322 °C and proceeded with the mass loss of 97.1%. Applying starch reduced the T5% by 24 °C and 32 °C for 10 phr and 20 phr of this biofiller, respectively. Thus, the T5% decreased with increasing amount of starch in the vulcanizate. Therefore, it was concluded that deterioration of the thermal stability of NR vulcanizates was due to the thermal decomposition of starch, which proceeded at a lower temperature than the thermal decomposition of NR in the unfilled vulcanizate. It is also confirmed by the small peak in the DTG curve, which was observed for the starch-filled vulcanizates at a temperature above 300 °C. It should be mentioned that thermal decomposition of pure starch proceeded with a sharp peak on the DTG curve at a temperature of approximately 318 °C. It resulted from the degradation of organic components of starch such as amylose and amylopectin [As expected, the type of biofiller and additives affected the onset decomposition temperature (Tlopectin .5% of NR vulcanizates by 33 °C (10 WS) and 48 °C (20 WS) compared to the unfilled benchmark. Thus, walnut shells deteriorated the thermal stability of NR vulcanizates to a greater extent than the starch. It was due to the lower thermal stability of pure walnut shells compared to the pure starch as confirmed by TG results of biofillers presented in 5% and TDTG of NR vulcanizates. T5% of the vulcanizates containing APTES and BmiCl was 3–10 °C lower compared to the vulcanizates without these additives.Walnut shells reduced TThe mass loss at 25–600 °C for the starch-filled vulcanizates was practically the same as for the unfilled benchmark, while it was slightly lower for the vulcanizates containing APTES and BmiCl (mass loss of approximately 91%). It resulted from the lower rubber content in the same amount of rubber compound compared to the unfilled vulcanizate.Regarding the mass loss at 25–600 °C for the vulcanizates filled with walnut shells, it was approximately 5–8% lower compared to the unfilled benchmark and vulcanizates filled with starch. Ground walnut shells contain not only organic components, which decompose at this step, but also minerals, such as K, Ca and Mg, which do not degrade in the temperature range of 25–600 °C . TherefoAlthough biofillers worsened the thermal stability compared to the unfilled vulcanizate, it should be noted that NR composites filled with starch or walnut shells were thermally stable up to a temperature of approximately 270 °C.3 was supplied by Torimex Chemicals . A conventional crosslinking system was used, containing sulfur with a purity of 99.9%  as a curing agent, microsized zinc oxide (ZnO) with a specific surface area of 10 m2/g and purity of 99.0%  as a vulcanization activator and 2-mercaptobenzothiazole (MBT) with purity of 98.0% applied as an accelerator . Stearic acid (St.A.) purchased from Akzo Nobel  was used as the softener and filler-dispersing agent. Natural bioadditives with different characteristics such as ground walnut shells (WS) and corn starch (St) obtained from Plantago  were used as fillers for NR compounds. Additionally; ionic liquid, i.e., 1-butyl-3-methylimidazolium chloride (BmiCl) with purity of ≥99.0%, supplied by IoLiTec Ionic Liquids Technologies GmbH, Heilbronn, Germany; and aminosilane such as (3-aminopropyl)-triethoxysilane  were applied to improve the compatibility between the elastomer matrix and biocomponents added. The structure of BmiCl and APTES was presented in Natural rubber  of RSS1 type with a density of 0.930–0.988 g/cm−1. The average temperature of the rolls during rubber preparation was approximately 30 °C. In the case of NR compounds containing ionic liquid and silane, biofillers were mixed with APTES and BmiCl, respectively, before being incorporated into the rubber compounds. Then, the mixtures of biofillers with a proper additive were introduced into the rubber composites.NR compounds were prepared according to the general formulations presented in In order to obtain plates of the vulcanizates, NR compounds were cured at 160 °C, at 15 MPa pressure using the optimal vulcanization times determined during rheometric tests. The vulcanization of NR compounds was carried out using a hydraulic press with electrical heating.90) was determined as a parameter corresponding to the time required for the rubber compound to reach 90% of the maximum torque as given by Equation (1), where ΔS is the torque increase during rheometric test, calculated as the difference between the maximum (Smax) and the minimum (Smin) torque. Adapting the similar equation, the scorch time (t02) was determined.The curing behavior of NR compounds was investigated at 160 °C according to the ISO 6502  standardTo determine the effect of biofillers, BmiCl and APTES on the temperatures and enthalpy of NR vulcanization, a differential scanning calorimeter DSC1  was employed. Using a STARe software , the onset temperature of the peak corresponding to the crosslinking reactions was determined according to the ISO 11357-1  standardχ) given by Equation (2), where rV is the volume of the elastomer fraction in swollen gel [According to the ISO 1817  standardllen gel .(2)χ=0.Scanning electron microscopy (SEM) was employed to study the dispersion of biofillers and other additives in the NR elastomer matrix. SEM images of NR vulcanizates were taken using a LEO1450 SEM microscope . Prior to the measurement, vulcanizates were broken down using liquid nitrogen. In the next step, their fractures were coated with carbon and then examined. Energy-dispersive X-ray spectroscopy (EDS) was employed to investigate the morphology and size of corn starch and ground walnut shells particles. Samples of pure fillers were coated with carbon to improve the quality of the obtained results. EDS spectra were collected to establish the elemental composition of the fillers used.Mechanical properties of NR vulcanizates under static conditions were investigated following to the ISO 37  standardZwick Roell 3105  hardness tester was used to establish the hardness of NR vulcanizates using Shore’s A method according to the standard ISO 868 . Measureg) was designated from the maximum of the tan δ = f (T) curve, where tan δ is the mechanical loss factor, and T is the measurement temperature.Dynamic mechanical analysis (DMA) was performed in tension mode using a DMA/SDTA861e analyzer . The measurements were carried out in the temperature range of −100–80 °C with a heating rate of 3 K/min, a frequency of 1 Hz and a strain amplitude of 4 µm. Tests were performed for strip-shaped specimens with a width of 4 mm, length of 10.5 mm and a thickness of approximately 2 mm. Liquid nitrogen was applied as a cooling medium. The temperature of the elastomer glass transition (TThermogravimetric (TG) analysis was carried out to study the thermal behavior of pure biofillers and consequently their influence on the thermal stability of NR vulcanizates. Thermogravimetry/differential scanning calorimetry TGA/DSC1 analyzer  was applied to perform measurements for the samples with a mass of approximately 10 mg. Samples were placed in the open alumina crucibles with a capacity of 70 µL. Measurements were carried out using two-step procedure. First, specimens were heated in the temperature range of 25–600 °C in an argon atmosphere (gas flow of 50 mL/min) with a heating rate of 20 K/min. Subsequently, the gas was changed into air (gas flow of 50 mL/min), and heating was continued up to 800 °C with the same heating rate. In the case of pure biofillers, the powders were heated in the temperature range of 25–700 °C in an argon atmosphere, and then the gas was changed into air. The heating was continued up to 800 °C with the same heating rate (20 K/min).f), which quantifies the resistance of material to prolonged thermo-oxidation, was calculated according to Equation (3) [bE is the elongation at break.Following to the ISO 188 standard , the thetion (3) , where TThe aim of this work was to study the influence of biofillers on the curing characteristics and performance of natural rubber biocomposites. Corn starch and ground walnut shells were used as biodegradable and eco-friendly fillers of NR composites.The performed research proved that starch and ground walnut shells can be classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk or talc. Furthermore, ionic liquids, i.e., BmiCl, and aminosilane, i.e., APTES, can be successfully used to support the vulcanization and improve the performance of NR composites filled with starch and walnut shells.Applied biofillers affected the rheometric properties and cure characteristics of NR compounds. Both biofillers and additives used caused an increase in the maximum torque during vulcanization due to the introduction of the rigid phase of the filler into the elastomer matrix. The improvement of torque increase indicated the development of spatial structure in the crosslinked elastomer network, which was confirmed by the enhancement of the crosslink density of vulcanizates, especially those containing APTES and BmiCl as compared to the unfilled sample. These additives not only improved the crosslink density but also had a beneficial effect on the optimal vulcanization time and the onset vulcanization temperature, which were reduced compared to NR compounds without APTES and BmiCl.Vulcanizates containing starch, especially with addition of APTES and BmiCl, exhibited improved tensile properties as compared to the unfilled benchmark. It resulted from the higher crosslink density of these vulcanizates and from the homogenous dispersion of starch, which was mainly due to the acting of BmiCl. Regardless of the biofiller and additives used, NR vulcanizates exhibited approximately 200–300% lower elongation at break than the unfilled benchmark. It resulted from the increased crosslink density of these vulcanizates and increased stiffness due to the introduction of biofillers into the elastomer matrix. In contrast, biofillers APTES and BmiCl did not significantly affect the ability of NR vulcanizates to dampen vibrations.Walnut shell-filled vulcanizates demonstrated improved resistance to thermo-oxidative aging as compared to the unfilled benchmark and starch-filled composites. It resulted from the presence of lignin in the composition of walnut shells, the components of which belong to polyphenols, which have an antioxidant activity. The beneficial influence of BmiCl on the resistance to prolonged thermo-oxidation of the starch-filled NR composites was observed.


A 76-year-old female developed progressive local groin bulging. She received regular hemodialysis using a left-thigh polytetrafluoroethylene arteriovenous graft in the loop configuration. Lower extremity enhanced computed tomography showed a large low-density area around the graft 18 months after its creation, and perigraft seroma (PS) was suspected. The patient underwent PS excision followed by graft wrapping with two local hemostatic agents, oxidized regenerated cellulose, and a fibrin sealant. Local PS recurrence was not detected four months after surgery. We herein describe a surgical case of refractory PS successfully treated by graft wrapping using two local hemostatic agents. Its prevalence is reportedly 1.2%–2.4% after extra-anatomical bypass and 1.7% after arteriovenous graft (AVG) placement for hemodialysis (HD). Since PS is rare, there is no consensus on treatment strategies and management plans. PS may induce graft thrombosis, skin erosion, and secondary graft infection, ultimately resulting in graft failure. We present a surgical case of PS that was successfully treated by graft wrapping using two types of local hemostatic agents, and discuss and suggest clinical strategies and management plans following prosthetic graft implantation.Perigraft seroma (PS) is local fluid collection around a vascular graft. Based on the product information, this PTFE graft has an average outer surface porosity of 50 µm, and an average inner surface porosity of 20 µm. Thigh loop AVG was perfused from the proximal side of the superficial femoral artery to the proximal side of the great saphenous vein  tapered graft  in the loop configuration was introduced approximately 18 months ago at our institute. The PTFE graft was a slider graft placed using a standard implantation technique that included multiple precautions to avoid excessive graft ultrafiltration, such as never forcing saline or blood into the graft under pressure and removing the distal venous-side clamp first. As far as we checked, there were few previous reports of the incidence of PS in patients with lower extremity AVG, which was 5% of lower extremity AVGs more evident than upper limb AVGs. The reason for more incidents of PS with AVG placement at the lower extremity is suspected that subcutaneous dead space around prosthetic grafts might be more common in the groin area. To avoid AVG failure, surgical interventions are sometimes indicated for PS if it is refractory to treatment. Managing uncurable PS involves conservative therapy, such as local compression, followed by percutaneous drainage. However, this strategy may be ineffective and increase the risk of graft infection and failure. Surgical drainage with or without a graft’s primary or secondary replacement with a different material is also considered.PS sometimes occurs after prosthetic graft implantation, and it may have a negative impact on the clinical outcome of a vascular graft, ultimately leading to graft failure. The development of PS after creating AVG as vascular access for HD is a rare complication with a prevalence of only 1.7%.In this case, discrimination with lymphorrhea was needed. If this gelatinous component originated from lymphorrhea, bulging was located at both arterial and venous sides of anastomosis, and local bulging might be recognized just after surgical intervention. However, this bulging originated only from the arterial side of anastomosis and developed over 18 months after the creation of vascular access. Seroma almost invariably develops around the arterial portion of the graft in PTFE grafts placed for vascular access. Therefore, PS was suspected and diagnosed in this case. which was successful in 84% of patients. They suggested that the instillation of fibrin glue only into the space surrounding the affected graft was insufficient because it could not completely and stably coat the outer graft surface. In an experimental evaluation of fibrin glue for PTFE grafts, Tsuchida et al. concluded that its sealant effects on preventing late fluid leakage were inadequate. In the present case, we wrapped the PTFE graft using two types of local hemostatic agents because only one hemostatic agent may be insufficient to completely seal the outer grafts, resulting in the recurrence of PS. We expected both local hemostatic agents’ synergistic effects to successfully seal the graft.Based on previous findings, we discuss optimal strategies for surgical management of PS. Zanow et al. reported successful treatment of PS by fibrin sealing of the outer surface of PTFE grafts to prevent leakage, We recommend conservative therapy, such as local compression or percutaneous drainage, to reduce or prevent PS by inducing local adhesion, and reducing the subcutaneous dead space. The minimally invasive surgical approach of graft wrapping with local hemostatic agents, as described for the present case, may be performed if PS is not located at the puncture site of AVG. Graft replacement using a different graft material may be considered to prevent graft failure if PS is refractory to treatment. Although surgical interventions are a radical approach, our surgical technique may be an alternative option for treating refractory PS before the surgical replacement of a related prosthetic graft with a different material.Based on previous studies, reviews, and summaries, we propose a strategy for PS at the vascular access for HD.We herein described a surgical case of PS that was successfully treated by local graft wrapping using two types of hemostatic agents.