A comparative study of failure criteria in sheet metal forming analysis

Development of predictive capabilities of forming failure can help not only to reduce the experimental effort of formability characterization but also to accelerate the development of new or improved sheet metal alloys. This paper presents a comparative study on prediction of failures in sheet metals which leads to undesirable localized straining and/or fracture during the stamping process. The theoretical diffuse and localized necking models were applied. Several classical fracture criteria were also studied in the finite element analysis. All these models were used to predict the onset of failure and compare with the experimental cases. Comparison and validity of different failure criteria was discussed

Sociodemographic factors that affect the real treatment rate among patients diagnosed with benign prostatic hyperplasia

Background Real treatment rate among patients diagnosed with benign prostatic hyperplasia (BPH/LUTS) and also its association with sociodemographic factor (SDF) have not been extensively investigated. Methods Data were obtained from the 2006, 2008, 2010, 2012, 2014, and 2016 waves of the Korean Longitudinal Study of Aging (KLoSA). Among 10,254 individuals at the first baseline survey in 2006, a total of 4383 participants were ultimately included for final analysis. For statistical analysis, chi-square tests and generalized estimating equation regression models were conducted. Results The prevalence rate of BPH/LUTS was 6.1% (266/4383) and real treatment rate was 58.3 percent (155/266). After adjusting for all confounders, odds ratio (OR) for the treatment of prostate disease in patients ages 55-64 and 65 years or more was 1.884 times higher (95% CI 1.096-3.237; p = .022) and 2.989 times higher (95% CI 1.755-5.091; p < .0001) than patients ages under 55, respectively. The OR for treatment of prostate disease in those residing in urban areas was 0.756 times lower (95% CI 0.573-0.998; p = .048) than those residing in metropolitan areas. The OR for treatment of prostate disease in those with bad self-rated health was 1.886 times higher (95% CI 1.461-2.436; p < .0001), compared to those with good self-rated health. Conclusion The real treatment rate among patients diagnosed with BPH/LUTS was 58.3%, a larger treatment rate than earlier reports. However, there are still a large proportion of patients who do not seek treatment; and age, residential area, and self-rated health were all found to be associated with real treatment rate

Association between lower urinary tract symptoms and cigarette smoking or alcohol drinking

Background: Although there have been several studies about the relationship between alcohol or smoking and lower urinary tracts symptoms (LUTS). This study aimed to investigate the association between alcohol or smoking and severity of LUTS in men, as alcohol intake and cigarette smoking is important modifiable lifestyle factors for LUTS. Methods: A cross-sectional analysis has been performed and a total of 86,707 participants in Korean Community Health Survey were included for final analysis. The adjusted odds ratio (OR) or coefficient with 95% confidence interval (CI) estimates were described to show the association between alcohol consumption or cigarette smoking and LUTS. Results: Among the total subjects, 77,398 (89.3%), 7,532 (8.7%), and 1,777 (2.0%) had mild, moderate, and severe symptoms, respectively, according to International Prostate Symptom Score (IPSS) grade. Those who drank alcohol at least once per month were significantly associated with decreased risk of having the worst IPSS grade (OR: 0.80, 95% CI: 0.68 to 0.93). Those who smoked in the past but currently quitted and those who were daily smokers showed significantly increased risk of having the worst IPSS grade (past smoker, OR: 1.26, 95% CI: 1.14 to 1.39; daily smoker, OR: 1.21, 95% CI: 1.10 to 1.34). For nocturia, daily smoking showed positive effect (OR: 0.79, 95% CI: 0.75 to 0.84) whereas heavy alcohol drinking showed negative effect (OR: 1.22, 95% CI: 1.14 to 1.32) Conclusions: Alcohol showed positive effect on LUTS except nocturia whereas cigarette smoking had negative effect on LUTS except nocturia. Daily smoking showed positive effect on nocturia whereas heavy alcohol drinking showed negative effect on nocturia

Proanthocyanidin from Grape Seed Extracts Protects Indomethacin-Induced Small Intestinal Mucosal Injury

Proanthocyanidin (grape seed proanthocyanidin extracts, GSPEs) is an antioxidant and scavenges free radicals. Excessive oxidative stress and free radical production are major components in the pathogenesis of NSAID-induced small intestinal injury. We investigated the effect of GSPEs on indomethacin-induced intestinal mucosal injury in the rat. Rats were allocated into four groups: the null control group, the indomethacin control group, the low-dose GSPEs group, and the high-dose GSPEs group. GSPEs were administered for 4 days. Then indomethacin and GSPEs were coadministered for the following 2 days by oral route. The dose of indomethacin was 200 mg/Kg. The doses of GSPEs were 100 mg/Kg for low-dose group and 300 mg/Kg for high-dose group. Luminal bleeding was solely observed in one of 5 rats from indomethacin control group. The number of ulcer count was reduced to 0.1 ± 0.3 per rat in GSPEs treated group compared to 1.4 ± 0.5 per rat in indomethacin control group. Submucosal inflammatory cell infiltration was also reduced to 50% in GSPEs treated group. The tissue level of prostaglandin E2 was not affected by GSPEs treatment. GSPEs attenuated the indomethacin-induced small intestinal injury irrespective of the tissue PGE2 depletion and glutathione consumption

Sondheimer Oscillation as a Fingerprint of Surface Dirac Fermions

Topological states of matter challenge the paradigm of symmetry breaking, characterized by gapless boundary modes and protected by the topological property of the ground state. Recently, angle-resolved photoemission spectroscopy (ARPES) has revealed that semiconductors of Bi$_{2}$Se$_{3}$ and Bi$_{2}$Te$_{3}$ belong to such a class of materials. Here, we present undisputable evidence for the existence of gapless surface Dirac fermions from transport in Bi$_{2}$Te$_{3}$. We observe Sondheimer oscillation in magnetoresistance (MR). This oscillation originates from the quantization of motion due to the confinement of electrons within the surface layer. Based on Sondheimer's transport theory, we determine the thickness of the surface state from the oscillation data. In addition, we uncover the topological nature of the surface state, fitting consistently both the non-oscillatory part of MR and the Hall resistance. The side-jump contribution turns out to dominate around 1 T in Hall resistance while the Berry-curvature effect dominates in 3 T $\sim$ 4 T