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Search Results: 1 - 10 of 577246 matches for " Yi-Ming A Chen "
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A Novel Large Moment Antiferromagnetic Order in K0.8Fe1.6Se2 Superconductor

BAO Wei,HUANG Qing-Zhen,CHEN Gen-Fu,M A Green,WANG Du-Ming,HE Jun-Bao,QIU Yi-Ming,

中国物理快报 , 2011,
Abstract:
Electromagnetic Band Gap Loaded Square Waveguide Band-Pass Filter for Dual-Polarized Application  [PDF]
Yi-Ming Tang
Wireless Engineering and Technology (WET) , 2012, DOI: 10.4236/wet.2012.34030
Abstract: An Electromagnetic Band Gap (EBG) loaded square waveguide Band-Pass Filter (BPF) is proposed in this paper. It’s simply composed by symmetrically loading periodical metal diaphragms on each wall of a square waveguide. The influences of insert sizes and loading periods on the overall BPF performances are analyzed. Experimental results agree well with those predicted. 6 GHz pass-band with insert loss less than 1 dB, 2.5 GHz stop-band and larger than 25 dB polarization isolation can be obtained. The BPF can be applied in dual-polarized waveguide-based antenna-feed systems.
Retrospective survey of avian influenza H5N1 infection in Northern Vietnam by using a combinational serologic assay  [PDF]
Hoa Minh Luong, Sheng-Fan Wang, Vu Tan Trao, Marcelo Chen, Jason C. Huang, Phung Dac Cam, Yu-Ting Lin, Yi-Ming Arthur Chen
Health (Health) , 2012, DOI: 10.4236/health.2012.430149
Abstract: Outbreaks of highly pathogenic avian influenza H5N1 virus have occurred in Vietnam since 2003. However, how people got avian H5N1 infection in Northern Vietnam is still unclear. We therefore performed a combination of the serologic assays H5N1 ELISA and H5 western blot to detect anti-H5N1 specific antibodies. Sera samples of 149 subjects with suspected H5N1 infection from three provinces of Northern Vietnam were collected from September 2006 to March 2007. Our results indicated that this combinational assay showed high sensitivity (100%) and specificity (95%) when compared with hemagglutinin inhibition (HI) assay. Fifty-one sera samples (34.2%) contained specific antibodies against H5N1 viruses. Poultry raisers (32/77; 41.6%) showed higher H5N1 infection rates than slaughterers (12/41; 29.3%) and health care workers (7/31; 22.6%). Contact history with sick or dead poultry in household or slaughter-house (p < 0.05) and lack of protective equipment use when in contact with dead poultry (p < 0.05) were risk factors found to be associated with H5N1 infection. In this study, we established an alternative serologic assay for H5N1 diagnosis, and we hereby present seroepidemiologic data of H5N1 infection in Northern Vietnam.
Risk Factors for HIV-1 seroconversion among Taiwanese men visiting gay saunas who have sex with men
Yen-Ju Chen, Yu-Ting Lin, Marcelo Chen, Szu-Wei Huang, Su-Fen Lai, Wing-Wai Wong, Hung-Chin Tsai, Yu-Huei Lin, Hsin-Fu Liu, Shu-Yu Lyu, Yi-Ming A Chen
BMC Infectious Diseases , 2011, DOI: 10.1186/1471-2334-11-334
Abstract: 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.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 (≥ 2 vs. ≤ 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).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.Since the global outbreak of HIV/AIDS, HIV has been transmitted among different vulnerable populations. According to a recent review, the global trend of HIV-1 infection among men having sex with men (MSM) has continued to increase, especially in East Asia, Africa, and Russia [1]. As of September 2011, there were 22, 335 known cases of HIV infection in Taiwan, and Taiwanese nationals accounted for 96.5% of those cases. Of the Taiwanese nationals, 92.5% were male. Populations at risk for HIV infection include injection drug users (30.4%), homosexual men (38.3%), heterosexual men (21.6%), and bisexual men (8.1%). Therefore, MSM are a high risk group for HIV infection in Taiwan [2].Since 1996~
A Seamless Broadcasting Scheme with Live Video Support
Zeng-Yuan Yang,Yi-Ming Chen,Li-Ming Tseng
International Journal of Digital Multimedia Broadcasting , 2012, DOI: 10.1155/2012/373459
Abstract: Broadcasting schemes, such as the fast broadcasting and harmonic broadcasting schemes, significantly reduce the bandwidth requirement of video-on-demand services. In the real world, some history events are very hot. For example, every year in March, thousands of people connect to Internet to watch the live show of Oscar Night. Such actions easily cause the networks contested. However, the schemes mentioned previously cannot alleviate the problem because they do not support live broadcasting. In this paper, we analyze the requirements for transferring live videos. Based on the requirements, a time skewing approach is proposed to enable the broadcasting schemes to support live broadcasting. However, the improved schemes require extra bandwidth for live broadcasting once the length of live shows exceeds the default. Accordingly, we proposed a scalable binomial broadcasting scheme to transfer live videos using constant bandwidth by increasing clients’ waiting time. When the scheme finds that the length of a video exceeds the default, it doubles the length of to-be-played segments and then its required bandwidth is constant. 1. Introduction With the growth of broadband networks, the video-on-demand (VOD) [1] becomes realistic. Many studies start investigating VOD. One of important areas is to explore how to distribute the top ten or twenty so-called hot videos more efficiently. Broadcasting is one of the promising solutions. It transfers each video according to a fixed schedule and consumes constant bandwidth regardless of the presence or absence of requests for the video. That is, the system’s bandwidth requirement is independent of the number of users watching a given video. A basic broadcasting scheme is the batch scheme [2], which postpones the users’ requests for a certain amount of time and serves these requests in batch so that its bandwidth consumption is reduced. However, the batch scheme still requires quite large bandwidth for a hot video. For example, given a video of 120 minutes, if the maximum clients’ waiting time equals 10 minutes, the required bandwidth is 12 , where is the video playout rate. Many broadcasting schemes were proposed to further reduce the bandwidth requirement by using a set-top box (STB) at the client end. The schemes include the fast broadcasting (FB) [3, 4], pagoda broadcasting (PB) [5], new pagoda broadcasting (NPB) [5], recursive-frequency splitting (RFS) [6], staircase broadcasting (SB) [7], and harmonic broadcasting (HB) [8, 9] schemes, which divide a video into multiple segments and distribute them through several
Loss to Followup in HIV-Infected Patients from Asia-Pacific Region: Results from TAHOD
Jialun Zhou,Junko Tanuma,Romanee Chaiwarith,Christopher K. C. Lee,Matthew G. Law,Nagalingeswaran Kumarasamy,Praphan Phanuphak,Yi-Ming A. Chen,Sasisopin Kiertiburanakul,Fujie Zhang,Saphonn Vonthanak,Rossana Ditangco,Sanjay Pujari,Jun Yong Choi,Tuti Parwati Merati,Evy Yunihastuti,Patrick C. K. Li,Adeeba Kamarulzaman,Van Kinh Nguyen,Thi Thanh Thuy Pham,Poh Lian Lim
AIDS Research and Treatment , 2012, DOI: 10.1155/2012/375217
Abstract: This study examined characteristics of HIV-infected patients in the TREAT Asia HIV Observational Database who were lost to follow-up (LTFU) from treatment and care. Time from last clinic visit to 31 March 2009 was analysed to determine the interval that best classified LTFU. Patients defined as LTFU were then categorised into permanently LTFU (never returned) and temporary LTFU (re-entered later), and these groups compared. A total of 3626 patients were included (71% male). No clinic visits for 180 days was the best-performing LTFU definition (sensitivity 90.6%, specificity 92.3%). During 7697 person-years of follow-up, 1648 episodes of LFTU were recorded (21.4 per 100-person-years). Patients LFTU were younger ( ), had HIV viral load ≥500?copies/mL or missing ( ), had shorter history of HIV infection ( ), and received no, single- or double-antiretroviral therapy, or a triple-drug regimen containing a protease inhibitor ( ). 48% of patients LTFU never returned. These patients were more likely to have low or missing haemoglobin ( ), missing recent HIV viral load ( ), negative hepatitis C test ( ), and previous temporary LTFU episodes ( ). Our analyses suggest that patients not seen at a clinic for 180 days are at high risk of permanent LTFU, and should be aggressively traced. 1. Introduction Loss to followup (LTFU) in patients receiving antiretroviral therapy can cause serious consequences such as discontinuation of treatment and increased risk of death [1–3]. At a program level, LTFU can make it difficult to evaluate outcomes of treatment and care [4, 5]. In resource-limited settings, where treatment has become rapidly available following the rollout of antiretroviral therapy, LTFU presents even more challenging obstacles that require special consideration and approaches [6, 7]. One of the key questions in patient followup is how to define a patient as LTFU. This has varied in studies conducted in different settings [8–10]. Defining LTFU using a very early threshold, for example, a patient with no clinic visit in the last three months, may result in many patients being considered as LTFU who would return to clinic naturally at a later date. Defining LTFU with a long threshold, for example, one year, may mean delaying too long before any effort is made to track patients potentially at risk of LTFU. The majority of research into LTFU in HIV-infected patients receiving antiretroviral treatment in resource-limited settings has been conducted in the sub-Saharan Africa region [3, 10–13]. A few studies have been conducted among Asian, mostly female, patients
Risk and prognostic significance of tuberculosis in patients from The TREAT Asia HIV Observational Database
Jialun Zhou, Julian Elliott, Patrick CK Li, Poh Lim, Sasisopin Kiertiburanakul, Nagalingeswaran Kumarasamy, Tuti Merati, Sanjay Pujari, Yi-Ming A Chen, Praphan Phanuphak, Saphonn Vonthanak, Thira Sirisanthana, Somnuek Sungkanuparph, Christopher KC Lee, Adeeba Kamarulzaman, Shinichi Oka, Fujie Zhang, Goa Tau, Rossana Ditangco
BMC Infectious Diseases , 2009, DOI: 10.1186/1471-2334-9-46
Abstract: The risk of TB diagnosis after recruitment was assessed in patients with prospective follow-up. TB diagnosis was fitted as a time-dependent variable in assessing overall survival.At baseline, 22% of patients were diagnosed with TB. TB incidence was 1.98 per 100 person-years during follow up, with predictors including younger age, lower recent CD4 count, duration of antiretroviral treatment, and living in high TB burden countries. Among 3279 patients during 6968 person-years, 142 died (2.04 per 100 person-years). Compared to patients with CDC category A or B illness only, mortality was marginally higher in patients with single Non-TB AIDS defining illness (ADI), or TB only (adjusted HR 1.35, p = 0.173) and highest in patients with multiple non-TB AIDS or both TB and other ADI (adjusted HR 2.21, p < 0.001).The risk of TB diagnosis was associated with increasing immunodeficiency and partly reduced by antiretroviral treatment. The prognosis of developing TB appeared to be similar to that following a diagnosis of other non-TB ADI.The use of highly active antiretroviral therapy (HAART) has led to dramatic reductions in morbidity and mortality in HIV patients [1,2]. However, tuberculosis (TB) remains a common opportunistic infections and a major cause of death among patients with HIV, especially in sub-Saharan African and Asian countries [3-5], where there is a high background prevalence of TB [5-7].The risk of TB in HIV-infected patients and the impact of TB diagnosis on disease progression in HIV infected patients have been well described in Africa [3,8-10]. The Asia-Pacific region has a large burden of both tuberculosis [7], with nearly 5 million prevalent cases and over 3 million new cases in 2006, and HIV, with an estimated 5 million people living with HIV and 380,000 new infections occurring in 2007 [11]. It is estimated that 2.5 million people are living with both infections in the region [5]. Despite the importance of these inter-related epidemics in the region, fe
Trends in CD4 counts in HIV-infected patients with HIV viral load monitoring while on combination antiretroviral treatment: results from The TREAT Asia HIV Observational Database
Jialun Zhou, Thira Sirisanthana, Sasisopin Kiertiburanakul, Yi-Ming A Chen, Ning Han, Poh_Lian Lim, Nagalingeswaran Kumarasamy, Jun Choi, Tuti Merati, Evy Yunihastuti, Shinichi Oka, Adeeba Kamarulzaman, Praphan Phanuphak, Christopher KC Lee, Patrick CK Li, Sanjay Pujari, Vanthanak Saphonn, Matthew G Law
BMC Infectious Diseases , 2010, DOI: 10.1186/1471-2334-10-361
Abstract: Treatment-naive HIV-infected patients who started cART with three or more and had three or more CD4 count and HIV VL tests were included. CD4 count slopes were expressed as changes of cells per microliter per year. Predictors of CD4 count slopes from 6 months after initiation were assessed by random-effects linear regression models.A total of 1676 patients (74% male) were included. The median time on cART was 4.2 years (IQR 2.5-5.8 years). In the final model, CD4 count slope was associated with age, concurrent HIV VL and CD4 count, disease stage, hepatitis B or C co-infection, and time since cART initiation. CD4 count continues to increase with HIV VL up to 20 000 copies/mL during 6-12 months after cART initiation. However, the HIV VL has to be controlled below 5 000, 4 000 and 500 copies/mL for the CD4 count slope to remain above 20 cells/microliter per year during 12-18, 18-24, and beyond 24 months after cART initiation.After cART initiation, CD4 counts continued to increase even when the concurrent HIV VL was detectable. However, HIV VL needed to be controlled at a lower level to maintain a positive CD4 count slope when cART continues. The effect on long-term outcomes through the possible development of HIV drug resistance remains uncertain.Studies show that latent infection of CD4 cells provides a mechanism for lifelong persistence of HIV-1, even in patients on effective anti-retroviral therapy [1]. To suppress viral replication so that the VL is below the level of detection with standard assays is thus one of the aims at the start of antiretroviral treatment. Maximal and durable suppression of HIV VL prevents or delays development of drug resistant mutations, preserves CD4 cells, and eventually results in better clinical outcomes. According to the US guidelines, if HIV VL suppression is not achieved, it is necessary to change to a new regimen, a second or third line regimen, with at least two active drugs [2].HIV-infected patients in most developing countries h
Triage vital signs predict in-hospital mortality among emergency department patients with acute poisoning: a case control study
Yu Jiun-Hao,Weng Yi-Ming,Chen Kuan-Fu,Chen Shou-Yen
BMC Health Services Research , 2012, DOI: 10.1186/1472-6963-12-262
Abstract: Background To document the relationship between triage vital signs and in-hospital mortality among emergency department (ED) patients with acute poisoning. Methods Poisoning patients who admitted to our emergency department during the study period were enrolled. Patient’s demographic data were collected and odds ratios (OR) of triage vital signs to in-hospital mortality were assessed. Receiver operating characteristic curve was used to determine the proper cut-off value of vital signs that predict in-hospital mortality. Logistic regression analysis was performed to test the association of in-hospital mortality and vital signs after adjusting for different variables. Results 997 acute poisoning patients were enrolled, with 70 fatal cases (6.7%). A J-shaped relationship was found between triage vital signs and in-hospital mortality. ED triage vital signs exceed cut-off values independently predict in-hospital mortality after adjusting for variables were as follow: body temperature <36 or >37°C, p < 0.01, OR = 2.8; systolic blood pressure <100 or >150 mmHg, p < 0.01, OR: 2.5; heart rate <35 or >120 bpm, p < 0.01, OR: 3.1; respiratory rate <16 or >20 per minute, p = 0.38, OR: 1.4. Conclusions Triage vital signs could predict in-hospital mortality among ED patients with acute poisoning. A J-curve relationship was found between triage vital signs and in-hospital mortality. ED physicians should take note of the extreme initial vital signs in these patients.
Germinal center kinase-like kinase (GLK/MAP4K3) expression is increased in adult-onset Still's disease and may act as an activity marker
Chen Der-Yuan,Chuang Huai-Chia,Lan Joung-Liang,Chen Yi-Ming
BMC Medicine , 2012, DOI: 10.1186/1741-7015-10-84
Abstract: Background Germinal center kinase-like kinase (GLK, also termed MAP4K3), a member of the MAP4K family, may regulate gene transcription, apoptosis and immune inflammation in response to extracellular signals. The enhanced expression of GLK has been shown to correspond with disease severity in patients with systemic lupus erythematosus. We investigated the role of GLK in the pathogenesis of adult-onset Still's disease, which shares some similar clinical characteristics with systemic lupus erythematosus. Methods The frequencies of circulating GLK-expressing T-cells in 24 patients with active adult-onset Still's disease and 12 healthy controls were determined by flow cytometry analysis. The expression levels of GLK proteins and transcripts were evaluated in peripheral blood mononuclear cells by immunoblotting and quantitative PCR. Serum levels of T helper (Th)17-related cytokines, including IL-1β, IL-6, IL-17 and TNF-α, were measured by ELISA. Results Significantly higher median frequencies of circulating GLK-expressing T-cells were observed in patients with adult-onset Still's disease (31.85%) than in healthy volunteers (8.93%, P <0.001). The relative expression levels of GLK proteins and transcripts were also significantly higher in patients with adult-onset Still's disease (median, 1.74 and 2.35, respectively) compared with those in healthy controls (0.66 and 0.92, respectively, both P <0.001). The disease activity scores were positively correlated with the frequencies of circulating GLK-expressing T-cells (r = 0.599, P <0.005) and the levels of GLK proteins (r = 0.435, P <0.05) or GLK transcripts (r = 0.452, P <0.05) in patients with adult-onset Still's disease. Among the examined Th17-related cytokines, elevated levels of serum IL-6 and IL-17 were positively correlated with the frequencies of circulating GLK-expressing T-cells and the levels of GLK proteins as well as transcripts in patients with adult-onset Still's disease. GLK expression levels decreased significantly after effective therapy in these patients. Conclusions Elevated expression levels of GLK and their positive correlation with disease activity in patients with adult-onset Still's disease indicate that GLK may be involved in the pathogenesis and act as a novel activity biomarker of this disease.
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