Augmented finite element method for virtual testing of high temperature CMCs

Ceramic matrix composites (CMCs) have been increasingly used in high heat flux applications due to their ultra-high temperature resisting capabilities. However, CMCs are prone to processing-induced or in-serve cracking due to the large thermal stresses. Thermally-induced cracking are dangerous because they provide pathways for further damaging processes such as oxidation and vapor-assisted corrosion, which may lead to catastrophic failure [1]. High-fidelity thermal-mechanical analyses to CMCs with consideration of arbitrary cracking are very challenging because the heterogeneous nature makes it impossible to know the cracking locations a priori. Yet correct and efficient treatment of crack coalescence and bifurcation is critical for simulating the complex, multiple crack damage states in these materials. In the past years we have been developing a new simulation method named augmented finite element method (A-FEM) with temperature DoFs that can efficiently and faithfully account for the arbitrary cracking and the post-crack material damage accumulation in CMCs [2, 3]. The high accuracy and efficiency of the A-FEM is enabled by three key numerical capabilities developed in recent years: 1) a novel condensation method that enables mesh insensitive and accurate fracture predictions with mesh sizes 10~50 times larger, and computational times 100x~1000x times shorter, than other methods such as X-FEM, G-FEM, and PNM; 2) a unified cohesive zone model (CZM) that can predict static, fatigue, or dynamic crack initiation in general heterogeneous materials, followed by coupled crack propagation until final failure; and 3) a novel and very fast method to avoid numerical divergence due to unstable crack growth. The high-fidelity simulation capabilities pave the way for achieving virtual testing of complex CMCs at various scales from microscopic fiber/matrix interaction to structural integrity, all with explicit consideration of multiple cracking and crack interactions. In this study, the concept and procedure of a top-down virtual testing strategy will be first introduced, with emphases on the needs for novel experimental methods for basic property characterizing and results validation and advanced numerical methods for high-fidelity predictions at all important scales. The virtual testing scheme will then be demonstrated by a detailed review of a recent exercise on a high-temperature textile CMC, including the use of micro-computer-tomography (mCT) for material heterogeneity characterization, the generation of virtual test specimens with the statistic tow/matrix information from the mCT characterization, full 3D A-FEM modeling of the virtual specimen for material and structural performance evaluation, and validation of the A-FEM simulated results against independent experimental testing results. The presentation will conclude with key lessons learned from this exercise and important future needs to make the virtual testing for routine engineering design practice

An Epidemiological Study of Hyperhidrosis Patients Visiting the Ajou University Hospital Hyperhidrosis Center in Korea

Hyperhidrosis is a disorder of perspiration in excess of the body's physiologic need and significantly impacts one's occupational, physical, emotional, and social life. The purpose of our study was to investigate the characteristics of primary hyperhidrosis in 255 patients at Ajou University Hospital Hyperhidrosis Center from March 2006, to February 2008. Information collected from the medical records was: sex, sites of hyperhidrosis, age at visit, age of onset, aggravating factors, hyperhidrosis disease severity scale (HDSS) rank, family history, occupation, and past treatment. A total of 255 patient records were reviewed; 57.6% were male. Patients with a family history (34.1%) showed a lower age of onset (13.21±5.80 yr vs. 16.04±9.83 yr in those without family history); 16.5% had previous treatment, most commonly oriental medicine. Palmar and plantar sites were the most commonly affected, and 87.9% of patients felt their sweating was intolerable and always interfered with their daily activities. Our study provides some original information on the Korean primary hyperhidrosis population. Patients who have a family history show signs of disease in early age than those without family history

The East Asian Journal of British History, vol. 2

The East Asian Journal of British History is produced by the East Asian Society of British History, and supported by the Institute for Historical Research. The Institute of Historical Research is pleased and proud to be supporting this recent addition to British history scholarship. Developing out of the IHR’s long-standing collaborative partnership with Japanese universities, and now in its fourth year, the East Asian Journal of British History features some of the best emergent scholarship from Anglophone historians working in China, Japan, and South Korea. Divided between an articles section and one devoted to reviews, the journal’s remit wide-ranging covering all fields and periods of British history. It complements the triennial Anglo-Japanese Conference organised by the IHR and Japanese historians based at the universities of Tokyo, Kyoto and Osaka, and the conference of the East Asian Society of British history, in which we are joined by our colleagues from South Korea. In future, we hope that more contributions will be featured in the journal from the Chinese mainland and from Taiwan

The effect of meditation on brain structure: cortical thickness mapping and diffusion tensor imaging

A convergent line of neuroscientific evidence suggests that meditation alters the functional and structural plasticity of distributed neural processes underlying attention and emotion. The purpose of this study was to examine the brain structural differences between a well-matched sample of long-term meditators and controls. We employed whole-brain cortical thickness analysis based on magnetic resonance imaging, and diffusion tensor imaging to quantify white matter integrity in the brains of 46 experienced meditators compared with 46 matched meditation-naïve volunteers. Meditators, compared with controls, showed significantly greater cortical thickness in the anterior regions of the brain, located in frontal and temporal areas, including the medial prefrontal cortex, superior frontal cortex, temporal pole and the middle and interior temporal cortices. Significantly thinner cortical thickness was found in the posterior regions of the brain, located in the parietal and occipital areas, including the postcentral cortex, inferior parietal cortex, middle occipital cortex and posterior cingulate cortex. Moreover, in the region adjacent to the medial prefrontal cortex, both higher fractional anisotropy values and greater cortical thickness were observed. Our findings suggest that long-term meditators have structural differences in both gray and white matter

Surgical Treatment of Non-Small Cell Lung Cancer with Isolated Synchronous Brain Metastases

This study is a retrospective examination of our experiences with patients who underwent treatment of isolated synchronous brain metastases coupled with primary non-small cell lung cancer. From January 1995 to June 2004, 12 patients presented with isolated synchronous brain metastases coupled with primary non-small cell lung cancer. The patient was comprised of 8 men and 4 women. The median age was 52 yr, in a range of 32 to 75 yr. Median follow-up duration was 10.6 months, in a range of 2 to 55.8 months. Recurrence developed in 7 patients, and the median interval from 1st treatment to recurrence was 4.5 months (2.8-6.5 months). The overall 1-yr survival rate was 61.7%. The 1-yr survival rates for pathologic N0 and N1 cases were 75% and 66.7%, respectively. The median survival duration for pathologic N2 was 6.2 months (95% CI, 4.8-7.5 months). The 1-yr survival rate for cases of single brain metastasis was 75%. Based on our current observations, we could speculate that aggressive management of primary non-small cell lung cancer and isolated synchronous brain metastases was beneficial in a selected group of patients, as long as the brain lesions and pulmonary lesions were limited or resectable

Effect of Chongkukjang on histamine-induced skin wheal response: A randomized, double-blind, placebo-controlled trial

AbstractBackgroundStudies in animals have demonstrated the antiallergenic properties of Chongkukjang (CKJ), a traditional Korean food made by fermentation of soybean with Bacillus subtilis. CKJ might therefore be used as an ingredient in a functional food designed to suppress allergies. The purpose of this study was to investigate the effect of CKJ on histamine-induced skin wheal response in healthy participants.MethodsA randomized, double-blind, placebo-controlled trial was conducted. Sixty participants (48 women and 12 men) were randomly assigned to one of two groups: One group received 35 g CKJ daily for 12 weeks, and the other received a placebo at the same dosing frequency. A skin prick test with histamine (10 mg/mL) was conducted on the ventral forearm 10 cm from the elbow, and assessed 15 minutes later. Outcomes included measurement of efficacy [skin wheal response, immunoglobulin E (IgE), histamine, interferon-gamma, interleukin-4, eosinophil, and eosinophil cationic protein (ECP)], and safety (adverse events, laboratory test results, electrocardiogram, anthropometric values, and vital signs).ResultsFifty-five participants (28 in the CKJ group and 27 in the placebo group) completed the study. After 12 weeks of supplementation, participants in the CKJ group showed a significant reduction in histamine-induced skin wheal areas compared with placebo group (p < 0.05). At 12 weeks, the CKJ group showed a significant improvement in percentage change from baseline in histamine-induced wheal area, compared with the placebo group (p < 0.05). CKJ did not influence blood levels of IgE, histamine, interferon-gamma, interleukin-4, eosinophil, or ECP.ConclusionOral administration of CKJ for 12 weeks resulted in a reduction of the skin wheal response to histamine, with no apparent adverse effects. Trial registration: ClinicalTrials.gov: NCT01402141

Efficacy and safety of intragastric balloon for obesity in Korea

Background/Aims Intragastric balloon (IGB) is the only available endoscopic bariatric and metabolic therapy in Korea. End-ball (Endalis) has the longest history of clinical use among the IGBs available in Korea. However, little clinical data on this system have been reported. In this study, we aimed to evaluate the efficacy and safety of End-ball in Korea. Methods We performed a retrospective cohort study of patients who underwent IGB insertion (End-ball) from 2013 to 2019. Demographic and anthropometric data were collected. The efficacy and safety of IGB treatment were analyzed. Results In total, 80 patients were included. Mean age was 33.7 years and 83.8% were female. Initial body mass index was 34.48±4.69 kg/m2. Body mass index reduction was 3.72±2.63 kg/m2 at the time of IGB removal. Percent of total body weight loss (%TBWL) was 10.76%±6.76%. Percentage excess body weight loss was 43.67%±27.59%. Most adverse events were minor, and 71.4% of participants showed nausea, vomiting, or abdominal pain. Conclusions IGB treatment showed good efficacy and safety profile in Korean patients with obesity. In terms of %TBWL and percentage excess body weight loss, the efficacy was similar to that in the Western population

Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation

A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active β-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear β-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach