79 research outputs found
The evaluation of lift and drag force for solid body with micro dimple
The present study explores the lift and drag mechanism, pressure distribution along the chord and flow visualization of the debossed dimpled- aerofoil with the aim to evaluation the effect of dimples on the aerodynamic characteristic on the aerofoil and find an optimisation on the dimples parameter in improving the aerodynamic performance. The issues on the fuel consumption, energy cost, aerodynamic performance efficiency for aerofoil application in turbine, automotive especially under unexpected weather condition such as air turbulence in air flight lead to the concern on improving the aerodynamic performance from time to time. In current context, the interaction of the dimple parameters influencing the aerodynamic behaviour of the aerofoil such as the dimple aspect ratio, shape, pitch resulting in variation of number of dimple is considered. An aerofoil sized 0.14m x 0.148m is tested under wind tunnel with different angle of attack and air velocity. The aerofoil flow visualizations under smoke test are captured with a high speed camera. A comparative study of the smooth and dimpled aerofoil with cylindrical (bluff) and hexagonal (blunt) dimple shape is investigated. From the result it is shown with the integration of dimple, the lift performance of the aerofoil is greatly improved with the delay of flow separation as a result from the streamwise vorticity reduces the turbulent skin drag. thus increasing the lift and the controllability of the aerofoil. The cylindrical dimpled aerofoil with the aspect ratio of 0.4 and pitch 8500 ΞΌm is highly recommended with the highest lift and lowest drag
Clinicopathological and prognostic significance of HER-2/neu and VEGF expression in colon carcinomas
<p>Abstract</p> <p>Background</p> <p>HER-2/neu and VEGF expression is correlated with disease behaviors in various cancers. However, evidence for their expression in colon cancer is rather contradictory both for the protein expression status and prognostic value. HER-2/neu is found to participate in VEGF regulation, and has known correlation with VEGF expression in some tumors. In this study, we investigated HER-2/neu and VEGF expression in Chinese colon patients and explored whether there was any correlation between their expression patterns.</p> <p>Methods</p> <p>HER-2/neu and VEGF were investigated immunohistochemically using tumor samples obtained from 317 colon cancer patients with all tumor stages. Correlation of the degree of staining with clinicopathological parameters and survival was investigated.</p> <p>Results</p> <p>Positive expression rates of HER-2/neu and VEGF in colon cancer were 15.5% and 55.5% respectively. HER-2/neu expression was significantly correlated with tumor size and distant metastases (<it>P </it>< 0.05), but was not an independent prognostic marker of survival <it>(P > 0.05)</it>. Expression of VEGF was significantly correlated with tumor size, tumor stage, lymph node metastases, and distant metastases (<it>P </it>< 0.05). The 5-year survival rate in patients with negative and positive VEGF expression was 70.2% and 61.9% respectively; the difference was not statistically significant <it>(P = 0.146)</it>. No correlation between HER-2/neu and VEGF expression was detected (<it>P = </it>0.151).</p> <p>Conclusions</p> <p>HER-2/neu and VEGF are not important prognostic markers of colon cancer. The present results do not support any association between HER2/neu and VEGF expression in this setting.</p
Kinetics of neutralizing antibodies against Omicron variant in Vietnamese healthcare workers after primary immunization with ChAdOx1-S and booster immunization with BNT162b2
We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research
Treatment results for hypopharyngeal cancer by different treatment strategies and its secondary primary- an experience in Taiwan
<p>Abstract</p> <p>Purpose</p> <p>The aim of this study was to evaluate treatment results in our hypopharyngeal cancer patients.</p> <p>Patients and Methods</p> <p>A total of three hundred and ninety five hypopharyngeal cancer patients received radical treatment at our hospital; 96% were male. The majority were habitual smokers (88%), alcohol drinkers (73%) and/or betel quid chewers (51%). All patients received a CT scan or MRI for tumor staging before treatment. The stage distribution was stage I: 2 (0.5%); stage II: 22 (5.6%); stage III: 57 (14.4%) and stage IV: 314 (79.5%). Radical surgery was used first in 81 patients (20.5%), and the remaining patients (79.5%) received organ preservation-intended treatment (OPIT). In the OPIT group, 46 patients received radiotherapy alone, 156 patients received chemotherapy followed by radiotherapy (CT/RT) and 112 patients received concomitant chemo-radiotherapy (CCRT).</p> <p>Results</p> <p>The five-year overall survival rates for stages I/II, III and IV were 49.5%, 47.4% and 18.6%, respectively. There was no significant difference in overall and disease-specific survival rates between patients who received radical surgery first and those who received OPIT. In the OPIT group, CCRT tended to preserve the larynx better (p = 0.088), with three-year larynx preservation rates of 44.8% for CCRT and 27.2% for CT/RT. Thirty-seven patients developed a second malignancy, with an annual incidence of 4.6%.</p> <p>Conclusions</p> <p>There was no survival difference between OPIT and radical surgery in hypopharyngeal cancer patients at our hospital. CCRT may offer better laryngeal preservation than RT alone or CT/RT. However, prospective studies are still needed to confirm this finding. Additionally, second primary cancers are another important issue for hypopharyngeal cancer management.</p
Risk Factors for HIV-1 seroconversion among Taiwanese men visiting gay saunas who have sex with men
<p>Abstract</p> <p>Background</p> <p>Men having sex with men (MSM) accounts for 33.6% of all reported cases of HIV-1 infection in Taiwan. The aim of this study was to investigate the epidemiology of HIV-1 infection among MSM in gay saunas in Taiwan.</p> <p>Methods</p> <p>Patrons of 5 gay saunas were recruited for a weekly volunteer counseling and testing program from 2001 to 2005. Questionnaires were collected for a risk factor analysis. HIV-1 subtypes were determined using DNA sequencing and phylogenetic analyses.</p> <p>Results</p> <p>HIV-1 prevalence rates among MSM in gay saunas in 2001 through 2005 were 3.4%, 5.1%, 8.9%, 8.5%, and 8.3%, respectively. In total, 81 of 1, 093 (7.4%) MSM had HIV-1 infection. Fifty-two HIV-1 strains were genotyped, and all of them were subtype B. HIV-seropositive men were significantly younger than the seronegatives. Only 37.1% used condoms every time during sexual intercourse. A multivariate logistic regression analysis showed that the risk factors for HIV-1 were being uncircumcised (odds ratio (OR) = 2.19; 95% confidence interval (CI), 1.08~4.45); having sexual intercourse with at least 2 partners during each sauna visit (β₯ 2 vs. β€ 1, OR = 1.71; 95% CI, 1.02~2.89); and the role played during anal intercourse (versatile vs. an exclusively insertive role, OR = 2.76; 95% CI, 1.42~5.36).</p> <p>Conclusions</p> <p>Overall, 7.4% Taiwanese MSM participating in this study had HIV-1 subtype B infection. Uncircumcised, being versatile role during anal intercourse, and having sex with more than one person during each sauna visit were main risk factors for HIV-1 infection.</p
The Adiponectin Receptor Homologs in C. elegans Promote Energy Utilization and Homeostasis
Adiponectin is an adipokine with insulin-sensitising actions in vertebrates. Its receptors, AdipoR1 and AdipoR2, are PAQR-type proteins with 7-transmembrane domains and topologies reversed that of GPCR's, i.e. their C-termini are extracellular. We identified three adiponectin receptor homologs in the nematode C. elegans, named paqr-1, paqr-2 and paqr-3. These are differently expressed in the intestine (the main fat-storing tissue), hypodermis, muscles, neurons and secretory tissues, from which they could exert systemic effects. Analysis of mutants revealed that paqr-1 and -2 are novel metabolic regulators in C. elegans and that they act redundantly but independently from paqr-3. paqr-2 is the most important of the three paqr genes: mutants grow poorly, fail to adapt to growth at low temperature, and have a very high fat content with an abnormal enrichment in long (C20) poly-unsaturated fatty acids when combined with the paqr-1 mutation. paqr-2 mutants are also synthetic lethal with mutations in nhr-49, sbp-1 and fat-6, which are C. elegans homologs of nuclear hormone receptors, SREBP and FAT-6 (a Ξ9 desaturase), respectively. Like paqr-2, paqr-1 is also synthetic lethal with sbp-1. Mutations in aak-2, the C. elegans homolog of AMPK, or nhr-80, another nuclear hormone receptor gene, suppress the growth phenotype of paqr-2 mutants, probably because they restore the balance between energy expenditure and storage. We conclude that paqr-1 and paqr-2 are receptors that regulate fatty acid metabolism and cold adaptation in C. elegans, that their main function is to promote energy utilization rather than storage, and that PAQR class proteins have regulated metabolism in metazoans for at least 700 million years
BRAF Activation Initiates but Does Not Maintain Invasive Prostate Adenocarcinoma
Prostate cancer is the second leading cause of cancer-related deaths in men. Activation of MAP kinase signaling pathway has been implicated in advanced and androgen-independent prostate cancers, although formal genetic proof has been lacking. In the course of modeling malignant melanoma in a tyrosinase promoter transgenic system, we developed a genetically-engineered mouse (GEM) model of invasive prostate cancers, whereby an activating mutation of BRAFV600Eβa mutation found in βΌ10% of human prostate tumorsβwas targeted to the epithelial compartment of the prostate gland on the background of Ink4a/Arf deficiency. These GEM mice developed prostate gland hyperplasia with progression to rapidly growing invasive adenocarcinoma without evidence of AKT activation, providing genetic proof that activation of MAP kinase signaling is sufficient to drive prostate tumorigenesis. Importantly, genetic extinction of BRAFV600E in established prostate tumors did not lead to tumor regression, indicating that while sufficient to initiate development of invasive prostate adenocarcinoma, BRAFV600E is not required for its maintenance
Effects of traditional and cyber homophobic bullying in childhood on depression, anxiety, and physical pain in emerging adulthood and the moderating effects of social support among gay and bisexual men in Taiwan
Chien-Chuan Wang,1,2 Huang-Chi Lin,2,3 Mu-Hong Chen,4,5 Nai-Ying Ko,6,7 Yu-Ping Chang,8 I-Mei Lin,9 Cheng-Fang Yen2,3 1Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan; 2Department of Psychiatry, Graduate Institute of Medicine and Department of Psychiatry, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Department of Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 4Division of Child and Adolescent Psychiatry, Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan; 5Department of Psychiatry, College of Medicine, National Yang-Ming University, Taipei, Taiwan; 6Department of Nursing, College of Medicine, National Cheng Kung University, Tainan, Taiwan; 7Nursing Department and Center for Infection Control, National Cheng Kung University Hospital, Tainan, Taiwan; 8School of Nursing, The State University of New York, University at Buffalo, Buffalo, NY, USA; 9Department of Psychology, College of Humanities and Social Science, Kaohsiung Medical University, Kaohsiung, Taiwan Objective: This study examined the differences in the current levels of depression, anxiety, and physical pain in emerging adulthood among gay and bisexual men with various experiences of traditional and cyber homophobic bullying based on gender role nonconformity and sexual orientation and the moderating effects of family and peer support.Methods: A total of 500 gay or bisexual men (age 20–25 years) in Taiwan were recruited from August 2015 to July 2017. The levels of depression, anxiety, and physical pain among gay or bisexual men who had experienced both traditional and cyber homophobic bullying (n=109), only traditional or cyber bullying (n=173), and neither traditional nor cyber bullying during childhood (n=218) were compared. The moderating effects of family and peer support on the effects of homophobic bullying victimization on depression, anxiety, and physical pain were also examined.Results: Victims of any type of homophobic bullying in childhood had more severe depression, anxiety, and physical pain in emerging adulthood than nonvictims. Victims of both traditional and cyber homophobic bullying had more severe anxiety in adulthood than victims of only traditional or cyber homophobic bullying. Family but not peer support in childhood moderated the effects of homophobic bullying victimization on current levels of anxiety and physical pain in emerging adulthood among gay and bisexual men.Conclusion: The results of the present study support that early prevention and intervention for homophobic bullying and enhancement of family support are essential to reduce mental health problems in emergent adults among gay and bisexual men. Keywords: sexual minority, homophobia, harassment, gender role nonconformity, sexual orientation 
The role of the gastrointestinal tract in toxigenic Clostridium tetani infection: a case-control study
Tetanus arises from wound contamination with Clostridium tetani, but approximately one fifth of patients have no discernable entry wound. Clostridium tetani is culturable from animal feces, suggesting the gastrointestinal tract could be an endogenous reservoir or direct-entry portal, but human data are lacking. In this study of 101 Vietnamese adults with tetanus and 29 hospitalized control subjects, admission stool samples were cultured for C. tetani. Anti-tetanus toxin antibodies were measured by ELISA. Clostridium tetani toxigenicity was evaluated using polymerase chain reaction and sequencing. Toxigenic C. tetani was cultured from stool samples in 50 of 100 (50%) tetanus cases and 12 of 28 (42.9%) control subjects (P = 0.50), and stool samples of 44 of 85 (52.4%) tetanus cases with clinically identified wounds compared with 6 of 15 (47.6%) patients without clinically identified wounds (P = 0.28). Nine of 12 (75%) control subjects with toxigenic C. tetani in their stool samples lacked protective antibody concentrations. These findings fail to show evidence of an association between gastrointestinal C. tetani and tetanus infection, but emphasize the importance of increasing vaccination coverage
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