Prevalence and risk factors of hepatitis C among former blood donors in rural China

SummaryBackgroundIllegal commercial plasma and blood donation activities in the late 1980s and early 1990s caused a large number of hepatitis C virus (HCV) infections in rural areas of China.MethodsA cross-sectional survey was carried out in 2008, in which all residents in a former blood donation village in rural Hebei Province were invited for a questionnaire interview and testing for HCV antibodies. Questionnaires were administered to collect information about their personal status and commercial blood donation history, and HCV antibodies were tested by enzyme immunoassay.ResultsOf 520 villagers who participated in the interviews, 236 (45.4%) reported a history of selling whole blood or plasma. HCV seropositivity was confirmed in 148/520 (28.5%) interviewees and 101/236 (42.8%) former commercial plasma and blood donors. Selling plasma was the strongest independent predictor of HCV seropositivity (p=0.0037). Past history of an operation was also independently associated with HCV infection (p=0.0270).ConclusionsUnsafe practices during illegal plasma donation led to a high risk of HCV seropositivity for donors during the late 1980s and early 1990s. Many infected people suffered chronic hepatitis from that time onwards and urgently needed treatment and care

Triptolide Inhibits the Proliferation of Prostate Cancer Cells and Down-Regulates SUMO-Specific Protease 1 Expression

Recently, traditional Chinese medicine and medicinal herbs have attracted more attentions worldwide for its anti-tumor efficacy. Celastrol and Triptolide, two active components extracted from the Chinese herb Tripterygium wilfordii Hook F (known as Lei Gong Teng or Thunder of God Vine), have shown anti-tumor effects. Celastrol was identified as a natural 26 s proteasome inhibitor which promotes cell apoptosis and inhibits tumor growth. The effect and mechanism of Triptolide on prostate cancer (PCa) is not well studied. Here we demonstrated that Triptolide, more potent than Celastrol, inhibited cell growth and induced cell death in LNCaP and PC-3 cell lines. Triptolide also significantly inhibited the xenografted PC-3 tumor growth in nude mice. Moreover, Triptolide induced PCa cell apoptosis through caspases activation and PARP cleavage. Unbalance between SUMOylation and deSUMOylation was reported to play an important role in PCa progression. SUMO-specific protease 1 (SENP1) was thought to be a potential marker and therapeutical target of PCa. Importantly, we observed that Triptolide down-regulated SENP1 expression in both mRNA and protein levels in dose-dependent and time-dependent manners, resulting in an enhanced cellular SUMOylation in PCa cells. Meanwhile, Triptolide decreased AR and c-Jun expression at similar manners, and suppressed AR and c-Jun transcription activity. Furthermore, knockdown or ectopic SENP1, c-Jun and AR expression in PCa cells inhibited the Triptolide anti-PCa effects. Taken together, our data suggest that Triptolide is a natural compound with potential therapeutic value for PCa. Its anti-tumor activity may be attributed to mechanisms involving down-regulation of SENP1 that restores SUMOylation and deSUMOyaltion balance and negative regulation of AR and c-Jun expression that inhibits the AR and c-Jun mediated transcription in PCa

Dynamic Modeling and Parameter Identification of Double Casing Joints for Aircraft Fuel Pipelines

Double casing joints are flexible pipe joints used for connecting aircraft fuel pipelines, which can compensate for the displacement and corner of the connected pipes and have complex mechanical characteristics. However, it is difficult to use sensors to directly measure the mechanical connection parameters of flexible joints. In this paper, we construct a coupling dynamics model and parameter identification of a double casing joint. Firstly, we analyze the structure and working principle of double-layer casing joints and establish the dynamics model of a single-layer flexible joint based on the transfer matrix method. Then, we deduce the coupling matrix of the inner and outer pipeline according to the deformation coordination conditions combined with matrix dimension extension. We establish the coupling dynamics model of flow–solid coupling of double casing joints. Furthermore, parameters such as equivalent stiffness and damping of each motion of the double casing joint in the casing unit are identified using the force-state mapping (FSM) method, and an analytical solution in the frequency domain under hammering excitation is given by the dynamics model. Finally, the dynamics test bench of the double casing joint for aircraft fuel is set up, and the free mode test of the double casing joint assembly is carried out. The results show that under free boundary hammering excitation, the theoretical and experimental frequency-domain response results are well matched, both obtaining seven main resonance peaks, and the maximum error is 9.45%, which shows the validity of the pipeline dynamics modeling method with a double casing joint

Application of Fourier transform infrared (FT-IR) spectroscopy in determination of microalgal compositions

Fourier transform infrared spectroscopy (FT-IR) was applied in algal strain screening and monitoring cell composition dynamics in a marine microalga Isochrysis zhangjiangensis during algal cultivation. The content of lipid, carbohydrate and protein of samples determined by traditional methods had validated the accuracy of FT-IR method. For algal screening, the band absorption ratios of lipid/amide I and carbo/amide I from FT-IR measurements allowed for the selection of Isochrysis sp. and Tetraselmis subcordiformis as the most potential lipid and carbohydrate producers, respectively. The cell composition dynamics oft zhangjiangensis measured by FT-IR revealed the diversion of carbon allocation from protein to carbohydrate and neutral lipid when nitrogen-replete cells were subjected to nitrogen limitation. The carbo/amide I band absorption ratio had also been demonstrated to depict physiological status under nutrient stress in T. subcordiformis. FT-IR serves as a tool for the simultaneous measurement of lipid, carbohydrate, and protein content in cell. (C) 2013 Elsevier Ltd. All rights reserved

On passivity and passification of Markovian jump systems

The problem of delay-dependent robust passivity analysis and robust passification for uncertain Markovian jump linear systems (MJLs) with time-varying delay is discussed. The parameter uncertainties are time-varying but norm-bounded. Attention is focused on the design of passification controllers, which guarantee that the closed-loop MJLs is passive. By constructing a proper stochastic Lyapunov-Krasovskii functional and employing the free-weighting matrix technique, delay-dependent passivity and passification performance conditions are formulated. A numerical example is given to illustrate the usefulness of the proposed approaches

Coordinated regulation of nitrogen supply mode and initial cell density for energy storage compounds production with economized nitrogen utilization in a marine microalga Isochrysis zhangjiangensis

Lipids and carbohydrates are main energy storage compounds (ESC) of microalgae under stressed conditions and they are potential feedstock for biofuel production. Yet, the sustainable and commercially successful production of ESC in microalgae needs to consider nitrogen utilization efficiency. Here the impact of different initial cell densities (ICDs) on ESC accumulation in Isochrysis zhangjiangensis under two nitrogen supply modes (an initially equal concentration of nitrogen per-cell in the medium (N1) and an equal total concentration of nitrogen in the culture system (N2)) were investigated. The results demonstrated that the highest ESC yield (1.36 g L-1) at N1, which included a maximal nitrogen supply in the cultivation system, and the highest ESC content (66.5%) and ESC productivity per mass of nitrogen (3.28 g g(-1) (N) day(-1)) at N2, were all obtained under a high ICD of 8.0 x 10(6) cells mL(-1). Therefore I. zhangjiangensis qualifies for ESC-enriched biomass production with economized nitrogen utilization. (C) 2015 Elsevier Ltd. All rights reserved

Identification of the role of polar glycerolipids in lipid metabolism and their acyl attribution for TAG accumulation in Nannochloropsis oceanica

Nannochloropsis, an ocean microalgal genus, is a promising resource of biodiesel feedstock because of its capacity for triacylglycerol (TAG) accumulation. Polar glycerolipids have big contribution for TAG accumulation by providing acyl group or diacylglycerol (DAG). Due to the diversities and amount of polar glycerolipids in species, a suitable approach has not been developed well to quantify and qualify, which veils the clarification of how important roles the polar glycerolipids play in microalgal lipid metabolism and TAG accumulation. In this study, a total of 112 polar glycerolipid species, covering eight classes, were identified using UPLC/Q-TRAP plus Orbitrap coupled with quantified using UPLC/Q-TOF. A comprehensive profiling of polar glycerolipid was established to study the polar glycerolipids variations in response to nitrogen deprivation in Nannochloropsis oceanica. Through targeted lipidomics analysis it was proposed that in N. oceanica, phosphatidylcholine (PC) serve as linoleic and gamma-linolenic acyl donors via oleic acyl desaturation, and under nitrogen stress condition PC transfers acyl 16:0 and 18:1 to TAG. The result disclosed PC played import roles for TAG accumulation not only in high plants but also in PC-containing microalgae even PC is not the most extraplastidial lipid. In addition, it was showed that phosphatidylethanolamine (PE) and diacylglyceryl-N-trimethylhomoserine (DGTS) are suppliers of eicosapentaenoic acid (EPA) to other lipids. These new discoveries reveal the diversity of microalgae in acyl metabolism and shed light on the understanding of lipid biosynthesis by stoichiometry. (C) 2017 Published by Elsevier B.V

Passivity analysis and passification of Markovian jump systems

This paper is concerned with the problems of delay-dependent robust passivity analysis and robust passification for uncertain Markovian jump linear systems (MJLSs) with time-varying delay. The parameter uncertainties are time varying but norm bounded. For the robust passivity problem, the objective is to seek conditions such that the closed-loop system under the state-feedback controller with given gains is passive, irrespective of all admissible parameter uncertainties. For the robust passification problem, desired passification controllers will be designed which guarantee that the closed-loop MJLS is passive. By constructing a proper stochastic Lyapunov-Krasovskii function and employing the free-weighting matrix technique, delay-dependent passivity/passification performance conditions are formulated in terms of linear matrix inequalities. Finally, the effectiveness of the proposed approaches is demonstrated by a numerical example

Robust H∞ filtering of Markovian jump stochastic systems with uncertain transition probabilities

This article investigates the problem of robust H∞ filtering for a class of uncertain Markovian stochastic systems. The system under consideration not only contains Itô-type stochastic disturbances and time-varying delays, but also involves uncertainties both in the system matrices and in the mode transition rate matrix. Our aim is to design an H∞ filter such that, for all admissible parameter uncertainties and time-delays, the filtering error system can be guaranteed to be robustly stochastically stable, and achieve a prescribed H∞ disturbance rejection attenuation level. By constructing a proper stochastic Lyapunov-Krasovskii functional and employing the free-weighting matrix technique, sufficient conditions for the existence of the desired filters are established in terms of linear matrix inequalities, which can be readily solved by standard numerical software. Finally, a numerical example is provided to show the utility of the developed approaches