Effects of Nonuniform Fiber Geometries on the Microstructural Fracture Behavior of Ceramic Matrix Composites

Microstructural fracture behavior of a ceramic matrix composite (CMC) with nonuniformly distributed fibers is studied in the presentation. A comprehensive numerical analysis package to study the effect of nonuniform fiber dimensions and locations on the microstructural fracture behavior is developed. The package starts with an optimization algorithm for generating representative volume element (RVE) models that are statistically equivalent to experimental measurements. Experimentally measured statistical data are used as constraints while the optimization algorithm is running. Virtual springs are utilized between any adjacent fibers to nonuniformly distribute the coated fibers in the RVE model. The virtual spring with the optimization algorithm can efficiently generate multiple RVEs that are statistically identical to each other. Smeared crack approach (SCA) is implemented to consider the fracture behavior of the CMC material in a mesh-objective manner. The RVEs are subjected to tension as well as the shear loading conditions. SCA is capable of predicting different fracture patterns, uniquely defined by not only the fiber arrangement but also the specific loading type. In addition, global stress-strain curves show that the microstructural fracture behavior of the RVEs is highly dependent on the fiber distributions

Shear behavior of a shear thickening fluid-impregnated aramid fabrics at high shear rate

Shear-thickening fluid-impregnated aramid (STF-im-AR) fabrics have been manufactured for advanced soft body armor applications for which they provide improved ballistic and stab resistances. It is not yet clear whether or not such improvements can be attributed solely to the STF. In this study, the rate-dependent behavior of an STF-im-AR fabric was investigated at the fabric level, using uniaxial tensile, bias-extension, and picture-frame tests. Rate-dependent behavior of the STF-im-AR fabric was observed during uniaxial tensile testing; however, the effect of the STF treatment was slight and consistent with only the inherent effect of the polymeric nature of its constituent fibers. The shear rigidity of the STF-im-AR fabric increased, due to the presence of the STF and the sensitivity of the fabric's shear stiffness to changes in the shear strain rate also increased slightly. This rate-sensitive shear stiffness of STF-im-AR fabrics may contribute to improved ballistic and stab resistances

Clinical efficacy and safety of autologous serum intramuscular injection in patients with mild-to-moderate atopic dermatitis: a prospective, open-label, uncontrolled study

Background Autologous blood therapy (ABT) has been used to treat atopic dermatitis (AD) for over a century, even though evidence supporting its efficacy is lacking. We aimed to investigate the effectiveness and safety of autologous serum intramuscular injection (ASIM), which is a modified form of ABT, in treating mild-to-moderate AD. Methods This study was a 12-week, open-label, prospective, uncontrolled trial. Following a 4-week run-in period, 22 out of 25 screened patients received ASIM once a week for 4 weeks in conjunction with standard treatment. The primary outcome measure was the Eczema Area and Severity Index (EASI), while the secondary outcomes included the Scoring Atopic Dermatitis (SCORAD) score, Dermatologic Life Quality Index (DLQI), and patient ratings of pruritus, sleep difficulty, disease status, and treatment effectiveness. Safety parameters were also assessed. Results EASI scores showed a non-statistically significant trend toward improvement during ASIM intervention. Patients with at least a 50% improvement in the EASI score at 4 weeks were older and had lower peripheral eosinophil counts (p<0.05). Secondary endpoints, including the SCORAD score, pruritus, sleep difficulty, and DLQI, demonstrated statistically significant improvements at week 4 compared to baseline (p<0.05). No significant adverse reactions were observed. Conclusions This pioneering study suggests that repeated ASIM may improve the clinical symptoms of mild-to-moderate AD, particularly in terms of pruritus and overall quality of life. However, further research with a larger sample size is required to establish the clinical significance of these findings

Specific Intracellular Uptake of Herceptin-Conjugated CdSe/ZnS Quantum Dots into Breast Cancer Cells

Herceptin, a typical monoclonal antibody, was immobilized on the surface of CdSe/ZnS core-shell quantum dots (QDs) to enhance their specific interactions with breast cancer cells (SK-BR3). the mean size of the core-shell quantum dots (28 nm), as determined by dynamic light scattering, increased to 86 nm after herceptin immobilization. the in vitro cell culture experiment showed that the keratin forming cancer cells (KB) proliferated well in the presence of herceptin-conjugated QDs (QD-Her, 5 nmol/mL), whereas most of the breast cancer cells (SK-BR3) had died. to clarify the mechanism of cell death, the interaction of SK-BR3 cells with QD-Her was examined by confocal laser scanning microscopy. as a result, the QD-Her bound specifically to the membrane of SK-BR3, which became almost saturated after 6 hours incubation. This suggests that the growth signal of breast cancer cells is inhibited completely by the specific binding of herceptin to the Her-2 receptor of SK-BR3 membrane, resulting in cell death

Identification and characterization of longevity assurance gene related to stress resistance in Brassica

Brassica is a very important vegetable group worldwide and different stresses are a major concern for these crops. Enhancement of resistance against biotic and abiotic stresses by exploiting stress resistance related genes offers the most efficient approach to address this concern. In this study, a stress resistance related gene was identified from the full-length cDNA library of Brassica rapa cv. Osome, which was determined to be Brassica longevity assurance protein (BrLAP) after sequence analysis. A comparison study of this gene showed a high degree of homology with other stress resistance related longevity assurance genes and was shown to be expressed in all organs during all of the developmental growth stages. In addition, this gene significantly responded after cold, drought and ABA stress treatments in Chinese cabbage. All these data revealed that this gene may be involved in plant resistance against stresses.Keywords: Brassica rapa, longevity assurance gene, gene expression, biotic and abiotic stres

Predisposing Factors of Ischemic Colitis: Data from 14 Years of Experience in a Single Center

Background and Aims. While several case reports on ischemic colitis (IC) suggest the presence of predisposing causative factors, a few studies have investigated the predisposing factors in IC. This study aimed to identify the characteristics of patients with IC, particularly focusing on the predisposing factors. Methods. We conducted a single-center, retrospective analysis of 159 patients with IC. Clinical characteristics, laboratory data, endoscopic findings, and medical records were reviewed. Data were compared between groups of patients defined according to the predisposing factors. The predisposing factors are defined as temporary states or episodic events occurring within a week before the development of IC such as colonoscopy, enema, use of laxatives, heavy drinking, pancreatitis, shock, and burn. Results. Compared to the group of patients without predisposing factors of IC, the group of patients with predisposing factors was characterized by a relatively higher prevalence of male sex (56.9% versus 33.3%, p=0.005), younger age (60.9 ± 15.4 versus 67.2 ± 13.4 years, p=0.010), lower incidence of hypertension (43.1% versus 60.2%, p=0.044), and fewer risk factors (1.24 ± 1.18 versus 1.82 ± 1.22, p=0.005). Conclusions. Among men with predisposing factors, IC may develop even at a relatively younger age and in the absence of multiple risk factors, suggesting that predisposing factors may be involved in the pathogenesis of IC

Intramuscular Hemangioma Mimicking Myofascial Pain Syndrome : A Case Report

Intramuscular hemangioma, an infrequent but important cause of musculoskeletal pain, is often difficult to establish the diagnosis clinically. This report describes a case of a 32-yr-old woman who presented with severe left calf pain for 10 yr. Initial conservative treatments consisting of intramuscular electrical stimulation, herb medication, acupuncture, and intramuscular lidocaine injection under the diagnosis of myofascial pain syndrome in other facilities, failed to alleviate the symptoms. On physical examination, there was no motor weakness or sensory change. Conventional radiography of the leg revealed a soft tissue phlebolith. Conventional angiography study showed hemangioma. Intramuscular hemangioma within the soleus muscle was confirmed by magnetic resonance imaging. Following surgical excision of the hemangioma, the patient's symptom resolved completely. Intramuscular hemangioma is a rare cause of calf pain and should be considered in the differential diagnosis if a patient with muscle pain, particularly if associated with a soft tissue mass, fails to respond to conservative treatment

Transphyseal Reconstruction of the Anterior Cruciate Ligament Using Hamstring Autograft in Skeletally Immature Adolescents

Eleven skeletally immature adolescents underwent anterior cruciate ligament reconstruction using a transphyseal tibial and femoral tunnel. An autologous quadrupled hamstring tendon was used in all cases and the average follow-up was 77.7 months. Clinical results were evaluated using Lysholm knee scores and a return to pre-injury sports activities. Radiological results were evaluated using side-to-side differences of instrumented laxities and growth disturbances compared with the uninjured side on final follow-up orthoroentgenograms. The mean Lysholm score was 97.8 (range 94-100) and mean side-to-side laxity difference was 2.4 mm (range 1-4). Ten of 11 patients returned to pre-injury sports activity. No patient had a leg length discrepancy of over 1 cm or a significant abnormal angular deformity of the knee joint. Therefore, anterior cruciate ligament reconstruction using the transphyseal tunnel and hamstring autograft in skeletally immature adolescents is believed to be a reliable treatment method, which is not associated with significant leg length discrepancy or abnormal angular deformity of the knee joint