The Effect of Carbon Black on the Properties of Plasticised Wheat Gluten Biopolymer.

Wheat gluten biopolymers generally become excessively rigid when processed without plasticisers, while the use of plasticisers, on the other hand, can deteriorate their mechanical properties. As such, this study investigated the effect of carbon black (CB) as a filler into glycerol-plasticised gluten to prepare gluten/CB biocomposites in order to eliminate the aforementioned drawback. Thus, biocomposites were manufactured using compression moulding followed by the determination of their mechanical, morphological, and chemical properties. The filler content of 4 wt% was found to be optimal for achieving increased tensile strength by 24%, and tensile modulus by 268% along with the toughness retention based on energy at break when compared with those of glycerol-plasticised gluten. When reaching the filler content up to 6 wt%, the tensile properties were found to be worsened, which can be ascribed to excessive agglomeration of carbon black at the high content levels within gluten matrices. Based on infrared spectroscopy, the results demonstrate an increased amount of ß-sheets, suggesting the formation of more aggregated protein networks induced by increasing the filler contents. However, the addition of fillers did not improve fire and water resistance in such bionanocomposites owing to the high blend ratio of plasticiser to gluten.

No correlation between femoral tunnel orientation and clinical outcome at long-term follow-up after non-anatomic anterior cruciate ligament reconstruction.

PURPOSE: This study aimed to determine the influence of femoral tunnel orientation on long-term clinical outcome and osteoarthritis in patients undergoing ACL reconstruction and to test the reliability of the implemented radiographic measurement methods. It was hypothesized that a more horizontal femoral tunnel would correlate with superior clinical outcome. METHODS: A cohort of 193 patients who underwent non-anatomic ACL reconstruction was examined. In this specific study, non-anatomic is defined by the surgeons' pursuit of optimal isometry, not to emulate the native ACL anatomy. At follow-up, the Lachman test, the KT-1000, the pivot-shift test, the one-leg-hop test and the IKDC-2000 were evaluated. Osteoarthritis was evaluated radiographically. Posteroanterior and lateral radiographs were used to determine the position of the femoral tunnel in the coronal and sagittal planes and the angle of the tunnel in the coronal plane. A method for determining femoral rotation on the lateral radiographs was developed and its reliability was evaluated. The femoral tunnel orientation was analyzed to examine its influence on clinical outcome and osteoarthritis. RESULTS: A total of 101 patients were analyzed at a mean of 16.4 (± 1.3) years postoperatively. The reliability of the measurement methods was regarded as good to excellent (ICC 0.57-0.97). The mean coronal femoral tunnel angle was 9.6° (± 9.4°). The coronal femoral tunnel was positioned at a mean of 43% (± 3.5%) of the distance measured from lateral to medial. The mean sagittal femoral tunnel position, measured using the quadrant method, was 40% (± 6.4%) from posterior to anterior. No significant associations were found between tunnel orientation and the clinical outcome variables. CONCLUSIONS: The orientation of the femoral tunnel did not predict the long-term subjective outcome, functional outcome or the development of osteoarthritis in patients undergoing non-anatomic ACL reconstruction. The method for determining femoral rotation on lateral radiographs was found to be reliable. LEVEL OF EVIDENCE: Retrospective cohort study, level of evidence IV.