Validation of the Chinese system for cardiac operative risk evaluation (SinoSCORE):the experience from Guangdong Cardiovascular Institute

Objective To validate of the Chinese system for cardiac operative risk evaluation (SinoSCORE) in Cantonese surgery patients. Methods Data from Guangdong Cardiovascular Institute in the period January 2004 through December 2008 were analyzed on 2462 Cantonese heart surgery patients. First,compared risk factors of this series and database of SinoSCORE,and then calculated

Protective effects of L-arginine against ischemia-reperfusion injury in non-heart beating rat liver graft

BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary graft loss. Prevention of liver injury in NHBDs will benefit the results of transplantation. This study was conducted to evaluate the protective effects of L-arginine on liver grafts from NHBDs. METHODS: One hundred and four Wistar rats were randomly divided into 7 groups: normal control (n=8) controls 1, 2 and 3 (C-1, C-2, C-3, n=16), and experimental 1, 2 and 3 (E-1, E-2, E-3, n=16). For groups C-1 and E-1, C-2 and E-2, and C-3 and E-3, the warm ischemia time was 0, 30, and 45 minutes, respectively. Liver grafts were flushed with and preserved in 4 degrees C Euro-collins solution containing 1 mmol/L L-arginine for 1 hour in each experimental group. Recipients of each experimental group were injected with L-arginine (10 mg/kg body weight) by tail vein 10 minutes before portal vein reperfusion. Donors and recipients of each experimental control group were treated with normal saline. Then transplantation was performed. At 1, 3, and 24 hours after portal vein reperfusion, blood samples were obtained to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) and plasma endothelin (ET). At 3 hours after portal vein reperfusion, grafts samples were fixed in 2.5% glutaraldehyde for electron microscopic observation. RESULTS: At I hour after portal vein reperfusion, the levels of NO in groups E-1, E-2, E-3 and C-1, C-2, C-3 were lower, while the levels of plasma ET, serum ALT and AST were higher than those in the normal control group (P<0.05). At 1, 3, and 24 hours, the levels of NO in groups E-1, E-2, E-3 were higher, while the levels of plasma ET, serum ALT and AST were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of NO in groups C-2 and C-3 were lower than in group C-1 (P<0.05), and the level of NO in group C-3 was lower than in group C-2 (P<0.05). At 1, 3 and 24 hours, the levels of plasma ET, serum ALT, and AST in groups E-1, E-2, E-3 were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of plasma ET, serum ALT, and AST were lower in group C-3 than in groups C-1 and C-2 (P<0.05). Pathological changes in groups E-1, E-2, E-3 were milder than those in the corresponding experimental control groups (C-1, C-2, C-3). CONCLUSIONS: The imbalance between NO and ET plays an important role in the development of ischemia-reperfusion injury of liver grafts from NHBDs. L-arginine can attenuate injury in liver grafts from NHBDs by improving the balance between NO and ET.

Optical 2-benzyl-5-hydroxy-4-oxopentanoic acids against carboxypeptidase A:Synthesis,kinetic evaluation and X-ray crystallographic study

2-Benzyl-5-hydroxy-4-oxopentanoic acid 1 and its enantiomers were designed,synthesized and assayed for inhibitory activity against carboxypeptidase A(CPA,EC 3.4.17.1).To verify the role of the terminal hydroxyl group in 1 binding to CPA,2-benzyl-5- benzyloxy-4-oxopentanoic acid 2 was also synthesized and evaluated.The inhibition constants show that both L-1 and D-1 were shown to have strong binding affinity with L-1 being more potent than its enantiomer by 165-fold.On the other hand,the inhibition constant ...

Protective Effect of Schisanhenol Against Oxygen Radical Induced Mitochondrial Toxicity on Rat Heart and Liver

Schisanhenol (SAL) had been shown to have potent antioxidant activities. The protective effects of SAL against oxygen radical induced mitochondrial injuries of rat heart and liver were investigated in the present study. The ferrous-cysteine induced mitochondrial lipid peroxidation was significantly inhibited by SAL, while the loss of ATPase activity induced by the lipid peroxidation was prevented. The rigidification of mitochondrial membrane, as well as swelling, lysis and disintegration of the mitochondria induced by ferrous-cysteine were all significantly inhibited by SAL. These results further confirm that SAL possesses antioxidant activity.

RISK ANALYSIS OF JACKET PLATFORMS DURING INSTALLATION ON SEA

In this paper, the uncertainty of environmental loads and soil resistance is analyzed, and the wave and current loads acting on a jacket during the unpiled installation phase are converted to its foundation loads. With a probability model of soil resistance, risk applied to the design of temporary seafloor support of a platform and the risk of failure, or probability of horizontal sliding, tilting and ovrturning can be pridicted. Thereby, optimum design and installation procedure may be chosen according to safety and economical factors. A Fortran program based on the model is developed. The application of the program to a jacket in South China Sea is described.

Cardioprotective effects of selective Na^＋/H^＋ exchanger inhibitor HOE642 against ischemia/reperfusion injury in immature hearts

Objective To compare the cardioprotective effect of HOE642, a highly selective Na^＋/H^＋ exchanger isoform-1 （NHE1） inhibitor, administered at different phase of ischemia/reperfusion in immature hearts： pre-ischemia, during ischemia and reperfusion.

New Polarographic Immunoassay Using Copper Ion as Catalyst for Conversion of Substrate Instead of Natural Enzyme

A new electrochemical immunoassay based on catalytic conversion of substrate by labeled metal ion and polarographic detection of generated product was developed. In this immunoassay,copper ion was used A catalyst for the conversion of substrate to substitute natural enzyme. Copper ion was labeled to antigens such as Human serum albumin(HSA), Diphtheria Toxoid (DT),Tetanus Toxoid (TT ) through bifunctional chelating agent diethylenetriamine pentaacetic acid (DTPA).After heterogeneous competitive immune reaction, the labeled copper ion was released by acidification, and then catalyzes chemically the conversion of substrate o-phenyldiamine (OPD ) to electroactive product 2,3-diaminophenazine (DAP). The product DAP was detected by using linearsweep polarography. The sensitivity of the proposed assay for the determination of HSA, DT and TT is superior to those of previous one based on direct detection of the labeled metal ion.

Prosthesis-patient mismatch in the mitral valve position:the initial result of a single-institutional observational study in China

Objective To analysis the causes of valve prosthesis-patient mismatch (PPM) after mitral valve replacement in Chinese patients. Methods Consecutive 100 patients for elective mitral valve replacement from January 2009 to June 2009 were enrolled and followed for this study. There were 37 males and 63 females.

Functions of spindle check-point and its relationship to chromosome instability

It is generally believed that the equal distribution of genetic materials to two daughter cells during mitosis is the key to cell health and development. During the dynamic process, spindle checkpoint plays a very important role in chromosome movements and final sister chromatid separation. The equal and precise segregation of chromosomes contributes to the genomic stability while aberrant separations result in chromosome instability that causes pathogenesis of certain diseases such as Down’s syndrome and cancers. Kinetochore and its regulatory proteins consist of the spindle checkpoint and determine the spatial and temporal orders of chromosome segregation.

Evidence for Asian summer monsoon precipitation instability of the Younger Dryas phase

The loess and desert transitional zone of China responses sensitively to the Asian monsoon fluctuations. A high resolution loess-dust and aeolian sand-paleosols section records the climatic history of the Younger Dryas. Based upon AMS 14C dating of pollen concentrates and proxy climate indices including magnetic susceptibility, organic carbon content and grain size, it is demonstrated that the Asian monsoon climate manifests not only cooling as in other regions of the Northern Hemisphere, but also unusual oscillations in precipitation which were probably associated with atmospheric interactions between both the Northern and Southern Hemispheres and atmospheric pressure anomalies of topic Pacific Ocean （ENSO）.

DNA-based immunization against hepatitis B surface antigen carrying preS epitopes

Three plasmid expression vectors containing modified hepatitis B surface antigen (HBsAg) carrying pres epitopes were constructed. Transient expression after in vitro transfection in COS-M6 cells showed that under the transcriptional control of the human cytomegalovirus (CMV) immediate early promoter, fusion genes expressed the modified HBV envelope proteins which were efficiently secreted into culture medium and presented HBsAg, preS1 and preS2 antigenicity. DNA-based immunization with these plasmids carrying pres sequences induced anti-HBs antibody in BALB/c mice. The titers of anti-HBs antibody were higher than those appeared in mice immunized with plasmid carrying S gene only. DNA injection with plasmids containing preS1 sequences elicited also high titers of anti-preS1 antibody. Moreover, the antipreS1 antibodies were found to appear earlier than anti-HBs antibodies.

Climatic instability recorded by the mollusk assemblages from the late glacial loess deposits in China

The loess-paleosol sequence in China records abundant and valuable information on the global and regional climate changes. Biological record from the loess sequence is the most direct evidence on variation in pattern of paleo-atmospheric circulation and changes in winter and summer monsoon. A new record of climatic instability, which occurred in the Loess Plateau during the late glacial period, is presented. Through the study of terrestrial mollusks from three loess sequences, the authors intend to characterize the biological response process to rapid climate change and to learn the mechanisms driving the instable climate changes and the possible linkage in different regions. The result shows the striking consistent variability in the ratio records of three mollusk sequences of the late glacial, indicating apparent rapid climate fluctuations. Correlation of our three mollusk records with the oxygen isotopic records from Greenland ice cores and foraminiferal records from the Northeast Pacific Ocean

Calibration and Experimental Research of a Multiple-wavelength Flame Temperature Instrumentation System

This paper presents a study on a novel instrumentation system for the measurement of temperature distribution of combustion flames. This system operates upon the three-color principle combining advanced optical sensing and digital image processing techniques. It comprises an endoscope, a light splitter assembly, a CCD camera, a frame-grabber and associated software. This system was calibrated using a blackbody furnace as standard temperature source. The relationship between flame temperatures and grey-level of the images was established through image processing and function correlation. Experimental results obtained on a gas-fired combustion rig provide flame images and temperature distributions on three different wavelengths. Based on the flame temperature distribution the combustion conditions can be analyzed. Experimental results also reveal that this system is capable of online measurement of temperature distribution in a combustion zone. This system can potentially be applied to many areas such as power generation, metallurgy, chemical engineering. It is also a powerful tool for improving the control of combustion process. Keywords three-color method - flame monitor - temperature - imaging processing CLC number TK311

Neuroprotective effects of Ginkgo biloba extract and GinkgoUde B against oxygen-glucose deprivation/reoxygenation and glucose injury in a new in vitro multicellular network model

Acute ischemic stroke （AIS）, as the third leading cause of death worldwide, is characterized by its high incidence, mortality rate, high incurred disability rate, and frequent reoccurrence. The neuroprotective effects of Ginkgo biloba extract （GBE） against several cerebral diseases have been reported in previous studies, but the underlying mechanisms of action are still unclear. Using a novel in vitro rat cortical capillary endothelial cell- astrocyte-neuron network model, we investigated the neuroprotective effects of GBE and one of its important constituents, Ginkgolide B （GB）, against oxygenglucose deprivation/reoxygenation and glucose （OGD/R） injury. In this model, rat cortical capillary endothelial cells, astrocytes, and neurons were cocultured so that they could be synchronously observed in the same system. Pretreatment with GBE or GB increased the neuron cell viability, ameliorated cell injury, and inhibited the cell apoptotic rate through Bax and Bcl-2 expression regulation after OGD/R injury. Furthermore, GBE or GB pretreatment enhanced the transendothelial electrical resistance of capillary endothelial monolayers, reduced the endothelial permeability coefficients for sodium fluorescein （Na-F）, and increased the expression levels of tight junction proteins, namely, ZO-1 and occludin, in endothelial cells. Results demonstrated the preventive effects of GBE on neuronal cell death and enhancement of the function of brain capillary endothelial monolayers after OGD/R injury in vitro; thus, GBE could be used as an effective neuroprotective agent for AIS/reperfusion, with GB as one of its significant constituents.

Ribavirin is effective against drug-resistant H7N9 influenza virus infections

Dear Editor, In February and March 2013, a novel influenza A （H7N9） virus emerged in China, causing an acute respiratory distress syndrome and occasionally multiple organ failure with high fatality rates in humans （Li et al., 2014）. A total of 681 laboratory-confirmed cases and 275 deaths have been reported as of November 13th,

MIDDLE EAR MECHANISMS IN PROTECTION AGAINST NOISE INDUCED COCHLEAR DAMAGE

Quantitative estimation of sound transmission attenuation by different middle-ear protecting mechanisms was made with the use of a computer-based CM-cogram analyzing method (FFT of cochlear output in response to white noise) and other audiometric means. Strong reflex contraction of the middle-ear muscles in guinea pigs may cause a 5- 20 dB transmission attenuation in different frequency ranges. For impulse noise exposure, the presence of an effective reflex at the lashing of every impulse may reduce the post - exposure hearing threshold shift in 15 dB on an average.Increasing tension of the tympanic membrane by applying pressure to the ear- canal is also eflicacious.especially for frequencies below 500 Hz where attenuation of more than 10dB may result at a pressure difference of about 200mm H2O between the two sides of the membrane. Simulated opening of the eustachian tube helps only very insignificantly, with attenuation less than 5 dB. Destruction of the middle-ear structures ( drum perforation, ossicular disruption etc .) and fluid accumulation inside the tympanic cavity may buffer acoustic trauma to the cochlea to different extent depending on the amount of transmission attenuation.

TURBULENCE MEASUREMENT INSTRUMENT WITH A SILICON PIEZORE-SISTANCE BEAM

Turbulence measurement is a sensitive technique and the study of an instrument for measuring the turbulence in liquids is of vital importance. A new instrument for measuring turbulence is introduced in this paper. The transducer of the device is based on the principle of the effect of the silicon piezoresistance, which is integrated in the Wheatstone bridge on a pure silicon beam. At one end of the beam, a small light ball is installed as the target forced by the water flow. The instrument is equipped with a microcomputer inside. The instrument can be used to measure turbulent velocities and either in clear water or in flows bearing hyperconcentration of sediment.

3-Anhydro-6-hydroxy-ophiobolin A displays high in vitro and in vivo efficacy against influenza A virus infection

Dear Editor, Influenza A virus （IAV） is an enveloped negative-strand RNA virus containing eight RNA segments that belongs to the family Orthomyxoviridae and can cause acute respiratory infection in humans and animals. Although vaccination is one of the major means for prophylaxis of influenza virus infection, a particular influenza vaccine only confers pro- tection for no more than a few years. In addition, the out- break of novel influenza infection cannot be predicted （Gao et al., 2013）. Thus, vaccine is unable to provide immediate protection against sudden influenza outbreaks with unknown identity. Development of antiviral drugs for therapeutic treatment is an important strategy to reduce the duration and severity of influenza. However,

Expression of rabbit defensin NP-1 gene in transgenic tobacco plants and its activity against bacterial wilt

A cDNAderived 200 bp fragment encoding a rabbit defensin NP1 mature peptide was ligated into the GUSless pBI121 to yield pBIC35NP1. Tobacco leaf discs were genetically transformed with an Agrobacterium tumefaciens strain harbouring pBIC35NP1. Northern blot analysis showed that the defensin NP1 expression cassette was normally transcribed in transgenic plants. Resistance tests demonstrated that expression of native defensin NP1 can confer partial resistance to the bacterial wilt pathogen, Ralstonia solanacearum.

斯特林机帽式密封性能分析及回归参数优化设计

为改善斯特林机活塞杆帽式密封性能,首先采用数值仿真分析了5 MPa工质压力下其静、动态力学特性,从而获取了O型圈内径尺寸L_(N)、C型环径向壁厚T和装配过盈量S这3个关键结构参数对密封性能的影响规律。在此基础上,利用回归设计法以配伍面最大接触压力平稳且密封可靠为优化目标,对密封结构的上述3个关键参数进行优化设计以确定其最佳匹配方案,最后通过密封试验台验证了本文优化设计方法的准确性和普适性。结果表明:活塞杆与C型环密封面中间区域上最大接触压力随L_(N)和S的增大而增大,但随T的增大而减小;通过估计回归系数和方差分析(ANOVA)发现,L_(N)对密封性能影响最为显著、S次之、T影响最小;L_(N)和T、L_(N)和S交互项对响应显著,而T和S交互项对响应不显著;当L_(N)为13.745 mm、T为0.40 mm和S为0.020 mm时,优化密封件对应的正行程最大接触压力为9.01 MPa、回程为9.75 MPa,较工程在用密封件(L_(N)=13.780 mm、T=0.50 mm、S=0 mm)最大接触压力分别降低了14.7%和25.5%。实验进一步验证了优化密封件的密封性能和使用寿命均优于工程在用密封件,并且在不同工质压力下优化密封件的接触压力均匀性更好,减摩延寿效果显著,充分证明本文性能分析与优化设计方法准确有效。