Digital Controller Candidate for Point-of-load Synchronous Buck Converter in Tri-mode Mechanism

Li-mei Xiu,Wei-ping Zhang,Bo Li,Yuan-sheng Liu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

A digital controller with a low-power approach for point-of-load synchronous buck converters is discussed and compared with its analog counterpart to confirm its feasibility for system integration. The tri-mode digital controller IC in 0.35 μm CMOS process is presented to demonstrate solutions that include a PID, quarter PID, and robust RST compensators. These compensators address the steady-state, stand-by, and transient modes according to the system operating point. An idle-tone free condition for S?D DPWM reduces the inherent tone noise under DC-excitation. Compared with that of the traditional approach, this condition generates a quasi-pure modulation signal. Experimental results verify the closed-loop performances and confirm the power-saving mechanism of the proposed controller.

Construction of antibacterial layer on polyvinylchloride three-channel hollow fiber membranes

Mei-Sheng Li,Ming-Xing Wang,Fei-Yue Wu,Xiao-Zhong Chu 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.39 No.-

The inner surfaces of polyvinylchloride (PVC) three-channel hollow fiber membranes were successfullymodified with poly(methacryloxylethyl benzyl dimethyl ammonium chloride) (PDMAE-BC) in a modulescale via remote plasma-induced surface graft polymerization method. After grafting a PDMAE-BC layer,the PVC surface hydrophilicity was improved greatly due to the introduction of large amounts of oxygenand nitrogen containing polar groups onto polymer backbone. This hydrophilicity improvement directlyleaded to a high pure water flux and a good antifouling property for the obtained PVC-PDMAE-BCmembrane module. Meanwhile, the inner surface morphologies of modified PVC membranes changedslightly and the surface structures were maintained well. The tensile strength, though deceased slightlyat the remote plasma-treated stage, showed no significant change during overall grafting process. Theobtained PVC-PDMAE-BC membrane module exhibited highly effective and stable antibacterialactivities against Escherichia coli. The antibacterial efficacy of PVC-PDMAE-BC membrane module withonly 6 fibers can achieve about 96.3% and could be further enhanced by increasing the packing density. The antibacterial membrane module may have great potential applications in actual wastewatertreatment and membrane bioreactor (MBR).

Indirect Determination of Cetirizine Hydrochloride by ICP-AES

Wang, Li-Sheng,Wei, Xiao-Ling,Gong, Qi,Jiang, Zhi-Liang,Li, Dong-Mei,Liang, Qing Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.2

Cetirizine hydrochloride reacted with $BiI_4^-$ in an acidic aqueous solution to form precipitate. After centrifugation, the atomic emission intensity of $Bi^{3+}$ contained in the supernatant solution was measured at the characteristic wavelength of 206.170 nm. The difference between the spectral signal intensity of the blank solution and that of the supernatant, ${\Delta}I$, was linearly related to the concentration of cetirizine hydrochloride. As a result, a new inductively coupled plasmaatomic emission spectrometric (ICP-AES) method was developed for the analysis of cetirizine hydrochloride. The linear range was from 27.7 to 184.8 $mg{\cdot}L^{-1}$, with a correlation coefficient (r) of 0.9961 and a detection limit of 9.6 $mg{\cdot}L^{-1}$. This method is simple and accurate, Without using toxic organic solvents, and is feasible for the quality control of cetirizine hydrochloride tablets and capsules.

Factors that Influence the Presciption of Antipsychotics for Patients with Schizophrenia in China

Tian-Mei Si,Liang Shu,Ke-Qing Li,Xie-He Liu,Qi-Yi Mei,Gao-Hua Wang,Pei-Shen Bai,Li-Ping Ji,Xian-Sheng Chen,Cui Ma,Jian-Guo Shi,Hong-Yan Zhang,Hong Ma,Xin Yu 대한정신약물학회 2011 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.9 No.3

Objective: To investigate the patterns of antipsychotic use in China and to analyze the factors that influence antipsychotic prescriptions. Methods: A standardized survey was conducted from May 20 to 24 2002 in five different regions of China with varying economic levels. The patterns of antipsychotic medication use were analyzed in a sample of 4,779 patients with schizophrenia. The survey gathered information on demographic characteristics, clinical profiles, and antipsychotic medications prescribed. Multiple logistic regression was used to analyze factors related to patterns of antipsychotic medication use. Results: A plurality of patients with schizophrenia was treated with clozapine (39%); this was followed by risperidone, sulpride,chlorpromazine, perphenazine, and haloperidol. More than 56.3% of patients were treated with only one atypical antipsychotic. The mean daily dose of chlorpromazine was 365±253 mg (mean±standard deviation), and 6.5% of patients were treated with depot injections of typical antipsychotic medications. A total of 73.7% (n=3,523) of patients with schizophrenia received monotherapy,24.8% (n=1,183) received two antipsychotics, 1.1% (n=52) received three antipsychotics, and one received four different antipsychotics. Patients often simultaneously received other classes of medications including anticholinergic agents, benzodiazepines,β-blockers, antidepressants, and mood stabilizers. Economic status and clinical symptoms were the main factors that contributed to the patterns of antipsychotic prescription. Conclusion: The present study suggests that atypical antipsychotic medications, especially clozapine, are the primary psychiatric treatments of choice in the management of schizophrenia in China. Moreover, the economic status and clinical profile of the patient are the major factors affecting the prescription of antipsychotic medication.

Digital Controller Candidate for Point-of-load Synchronous Buck Converter in Tri-mode Mechanism

Xiu, Li-Mei,Zhang, Wei-Ping,Li, Bo,Liu, Yuan-Sheng The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.4

A digital controller with a low-power approach for point-of-load synchronous buck converters is discussed and compared with its analog counterpart to confirm its feasibility for system integration. The tri-mode digital controller IC in $0.35{\mu}m$ CMOS process is presented to demonstrate solutions that include a PID, quarter PID, and robust RST compensators. These compensators address the steady-state, stand-by, and transient modes according to the system operating point. An idle-tone free condition for ${\Sigma}-{\Delta}$ DPWM reduces the inherent tone noise under DC-excitation. Compared with that of the traditional approach, this condition generates a quasi-pure modulation signal. Experimental results verify the closed-loop performances and confirm the power-saving mechanism of the proposed controller.

Use of Clozapine for the Treatment of Schizophrenia: Findings of the 2006 Research on the China Psychotropic Prescription Studies

Tian-Mei Si,Yun-shu Zhang,Liang Shu,Ke-Qing Li,Xie-He Liu,Qi-Yi Mei,Gao-Hua Wang,Pei-Shen Bai,Li-Ping Ji,Xian-Sheng Cheng,Cui Ma,Jian-Guo Shi,Hong-Yan Zhang,Hong Ma,Xin Yu 대한정신약물학회 2012 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.10 No.2

Objective: Clozapine is one of the most commonly used antipsychotic drugs in China. To date, few studies have investigated the patterns the prescription of clozapine nationwide. The present study examined these patterns in China in 2006 and identified the demographic and clinical characteristics associated with the use of clozapine. Methods: Using a standardized protocol and data collection procedure, we surveyed 5,898 patients with schizophrenia in 10provinces with differing levels of economic development. Results: Overall, clozapine had been prescribed for 31.9% (n=1,883) of the patients; however we found considerable variation among the 10 provinces. The frequency of clozapine use was highest in Sichuan (39.3%) and lowest in Beijing (17.3%). The mean daily dose of clozapine was 210.36±128.72 mg/day, and 25.1% of the patients were treated with clozapine in combination with other antipsychotics. Compared with the group not receiving clozapine, clozapine-user had been treated for longer durations and had experienced a greater number of relapses and hospitalizations. Furthermore, those in the clozapine-user had lower family incomes, were less able to seek psychiatric services, and more likely to be male and have a positive family history of schizophrenia. A multiple logistic regression analysis revealed that age, sex, professional help-seeking behaviors, duration of illness, economic status, educational level, and clinical manifestations were associated with the use of clozapine. Conclusion: Clozapine use is common in China. However, use of the antipsychotic varies among provinces, and demographic and clinical factors play important roles in the prescription of clozapine.

Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia

Cheng, Zhang,Li, Han-Han,Wang, Hong-sheng,Zhu, Xue-Mei,Sthiannopkao, Suthipong,Kim, Kyoung-Woong,Yasin, Mohamed Salleh Mohamed,Hashim, Jamal Hisham,Wong, Ming-Hung Elsevier 2016 Environmental research Vol.150 No.-

<P><B>Abstract</B></P> <P>Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of human to phthalates are limited. In this study, to assess the daily intakes of phthalate esters and the possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑phthalate ester concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 0.05 to 2.34 (median 0.88) μgg<SUP>−1</SUP>, 0.19–1.65 (median 0.86) μgg<SUP>−1</SUP> and 0.24–3.05 (median 0.59) μgg<SUP>−1</SUP> wet weight (ww), respectively. Di-2-Ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP) were the predominant compounds among all foodstuffs. The estimated daily intake (EDI) of phthalate esters for the general population in Kampong Cham, Kratie and Kandal was 34.3, 35.6 and 35.8μgkg<SUP>−1</SUP> bw d<SUP>−1</SUP>, respectively. The dietary daily intake of DEHP, benzylbutyl phthalate (BBP) and di-n-butyl phthalate (DBP) in Kampong Cham, Kratie and Kandal were below the tolerable daily intakes (TDI) imposed by the European Food Safety Authority (EFSA) and reference doses (RfD) imposed by The United States Environmental Protection Agency (USEPA). Rice contributed the greatest quantity of DEHP to the daily intake in Cambodia so may deserve further exploration. To our knowledge, this is the first study to investigate the occurrence and the daily intakes of phthalate esters in Cambodia.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phthalate esters concentration in daily foodstuffs collected from Cambodia. </LI> <LI> Investigate the bioaccessbility of phthalate esters via the foodstuffs consumption. </LI> <LI> Health risk evaluation of dietary exposure to phthalate esters. </LI> </UL> </P>

Decreased Expression of FADS1 Predicts a Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

Du, Yong,Yan, Shu-Mei,Gu, Wan-Yi,He, Fan,Huang, Li-Yun,Li, Mei,Yuan, Yan,Chen, Ren-Hui,Zhong, Qian,Li, Man-Zhi,Li, Yong,Zeng, Mu-Sheng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC. Immunohistochemical analyses revealed that 58.2% (146/251) of the ESCC tissues had low levels of FADS1 expression, whereas 41.8% (105/251) exhibited high levels of FADS1 expression. In positive cases, FADS1 expression was detected in the cytoplasm of cells. Correlation analyses demonstrated that FADS1 expression was significantly correlated with tumor location (p=0.025) but not with age, gender, histological grade, tumor status, nodal status or TNM staging. Furthermore, patients with tumors expressing high levels of FADS1had a longer disease-free survival time (p<0.001) and overall survival time (p <0.001). Univariate and multivariate analyses revealed that, along with nodal status, FADS1 expression was an independent and significant predictive factor (p<0.001). In conclusion, our study suggested that FADS1 might be a valuable biomarker and potential therapeutic target for ESCC.

Isolation, Characterization, and Molecular Cloning of the cDNA Encoding a Novel Phytase from Aspergillus niger 113 and High Expression in Pichia pastoris

( Ai Sheng Xiong ),( Quan Hong Yao ),( Ri He Peng ),( Xian Li ),( Hui Qin Fan ),( Mei Jin Guo ),( Si Liang Zhang ) 생화학분자생물학회 2004 BMB Reports Vol.37 No.3

Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyII) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyII and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyII and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyIIs, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pustoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of I? pustoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that -4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and anoptimum temperature of 60℃.

Association of Lipoprotein-Associated Phospholipase A_2 with Characteristics of Vulnerable Coronary Atherosclerotic Plaques

Yu-Sheng Liu,Qing-Hua Lu,Xiao-Bo Hu,Hong-Zhuan Li,Wei-Dong Jiang,Xin Wang,Hao Lin,Ai-Qiong Qin,Yong-Mei Wang,Tong Zhao,Zhao-Qiang Dong,Mei Zhang 연세대학교의과대학 2011 Yonsei medical journal Vol.52 No.6

Purpose: Lipoprotein-associated phospholipase A2 (Lp-PLA_2) is an inflammatory enzyme expressed in atherosclerotic plaques. We investigated the association of circulating Lp-PLA_2 with characteristics of vulnerable coronary atherosclerotic plaques. Materials and Methods: We recruited 113 patients with either unstable angina (UA, n=59) and stable angina (SA, n=54) by coronary angiography. Thirty-six healthy subjects served as controls. Intravascular ultrasound (IVUS) was used to evaluate the characteristics of coronary atherosclerotic plaque, and serum Lp-PLA2 concentration was measured as well. Results: Lp-PLA_2 concentration was significantly higher in both UA and SA patients [(396±36) μg/L and (321±39) μg/L, respectively]compared with the controls [(127±49) μg/L, p<0.01], and higher in UA than SA group. IVUS findings showed that remodeling index (RI) (0.91±0.15 vs. 0.85±0.11, p=0.005) and eccentricity index (EI) (0.73±0.16 vs. 0.65±0.22, p=0.039) were larger in UA than in SA group, and fibrous caps were thicker in SA than UA group [(0.91±0.23) mm vs. (0.63±0.21) mm, p=0.032]. Moreover, Lp-PLA_2 correlated positively with EI (r=0.439, p<0.01) and RI (r=0.592, p<0.05) in UA group. There was an inverse relationship between Lp-PLA_2 and fibrous cap thickness in both UA (r=-0.587, p<0.001) and SA (r=-0.318, p<0.05) groups. The independent risk factors in UA group were Lp-PLA_2 (OR=1.055, 95% CI: 1.03-1.08, p=0.013), LDL-cholesterol (OR=0.032, 95% CI: 0.00-0.05, p=0.041) and fibrous cap thickness (OR=0.008, 95% CI: 0.00-0.45, p=0.019). Lp-PLA_2 was strongly associated with both EI and fibrous cap thickness in both groups. Conclusion: Serum level of Lp-PLA_2 is associated with both eccentricity index and fibrous cap thickness in both UA and SA groups. Elevated levels of circulating Lp-PLA_2 might to be a strong risk factor and more serious for unstable angina than stable angina.