首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
Sevoflurane postconditioning reduces myocardial infarct size.The objective of this study was to examine the role of the phosphatidylinositol-3-kinase(PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro-and antiapoptotic proteins in sevoflurane postconditioning.Isolated and perfused rat hearts were prepared first,and then randomly assigned to the following groups:Sham-operation(Sham),ischemia/reperfusion(Con),sevoflurane postconditioning(SPC),Sham plus 100 nmol/L wortmannin(Sham+Wort),Con+Wort,SPC+Wort,and Con+dimethylsulphoxide(DMSO).Sevoflurane postconditioning was induced by administration of sevoflurane(2.5%,v/v) for 10 min from the onset of reperfusion.Left ventricular developed pressure(LVDP),left ventricular end-diastolic pressure(LVEDP),maximum increase in rate of LVDP(+dP/dt),maximum decrease in rate of LVDP(?dP/dt),heart rate(HR),and coronary flow(CF) were measured at baseline,R30 min(30 min of reperfusion),R60 min,R90 min,and R120 min.Creatine kinase(CK) and lactate dehydrogenase(LDH) were measured after 5 min and 10 min reperfusion.Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion.Total Akt and phosphorylated Akt(phospho-Akt),Bax,Bcl-2,Bad,and phospho-Bad were determined by Western blot analysis.Analysis of variance(ANOVA) and Student-Newman-Keuls' test were used to investigate the significance of differences between groups.The LVDP,±dP/dt,and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion(P0.05).The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9±8)% vs.(42.4±9.4)%,respectively;P0.05].The SPC group also had increased the expression of phospho-Akt,Bcl-2,and phospho-Bad,and decreased the expression of Bax.Wortmannin abolished the cardioprotection of sevoflurane postconditioning.Sevoflurane postconditioning may protect the isolated rat heart.Activation of PI3K and modulation of the expression of pro-and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.  相似文献   

2.
Objective: To study the stereoselective glucuronidation of carvedilol (CARV) by three Chinese liver microsomes. Methods: The metabolites of CARV were identified by a hydrolysis reaction with β-glucuronidase and HPLC-MS/MS. The enzyme kinetics for CARV enantiomers glucuronidation was determined by a reversed phase-high pressure liquid chromatogra-phy (RP-HPLC) assay using (S)-propafenone as internal standard after precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosylisothiocyanate. Results: Two CARV glucuronides were found in three Chinese liver microsomes incubated with CARV. The non-linear regression analysis showed that the values of Km and Vmax for (S)-CARV and (R)-CARV enantiomers were (118±44) μmol/L, (2 500±833) pmol/(min·mg protein) and (24±7) μmol/L, (953±399) pmol/(min·mg protein), respectively. Conclusion: These results suggested that there was a significant (P<0.05) stereoselective glucuronidation of CARV enantiomers in three Chinese liver microsomes, which might partly explain the enantioselective pharmacokinetics of CARV.  相似文献   

3.
INTRODUCTION In this paper we investigate the uniform ma-chines scheduling problem with machine activationcost. This problem has application in garment pro-duction of international trade and is motivated by thefollowing scenario. Import-export company is com-pared to scheduler in this model, and orders are jobs,which arrive one by one. And garment factories canbe regarded as machines. Since jobs should be fin-ished on time, scheduler will choose a reasonablenumber of machines to make the…  相似文献   

4.
Study of the SISO mixedH 2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound inl 2 norm with solvable suboptimal solutions and solvable superoptimal solutions. Project supported by the National Natural Science Foundation of China (No. 60174026) and the Scientific Research Foundation for Returned Overseas Chinese Scholars of Zhejiang Province (No. J20020546)  相似文献   

5.
To assess the influence of cyclosporin A (CsA) and tacrolimus (FK506) on mycophenolic acid (MPA) and correlation analysis of the pharmacokinetic parameters and patient characteristics, clinical outcome in Chinese kidney transplant recipients, the pharmacokinetics of 1000 mg mycophenolate mofetil (MMF) twice daily was measured by high-performance liquid chromatography (HPLC). PKS (Pharmaceutical Kinctics Software) 1.0.2 software package was used for the calculation of pharmacokinetic parameters. The meanC max,t max, and AUC(0–12) were (21.88±10.52) μg/ml, (1.20±0.95) h, and (52.546±13.215) μg·h/ml, respectively. The level of AUC(0–12) in the FK506 group was significantly higher than that in the CsA group. MPA appeared not to be affected by renal function. MPA AUC(0–12) showed statistically significant difference according to the patient's gender. Project (No. 20040462) supported by the Foundation of Education Bureau of Zhejiang Province, China  相似文献   

6.
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert…  相似文献   

7.
The long-arm and short-arm genes of fibroin light chain (L-chain) of silkworm,Bombyx Mori L., and the gene of human acidic fibroblast growth factor were cloned respectively and subsequently inserted into a transfer vector pVL 1392 used as a tool to target the L-chain region of the silkworm genome. Genomic DNA from their offsprings was extracted and the expected targeting was detected using polymerase chain reaction and DNA sequencing, as well as protein analysis. The results showed that positive events occurred and that the FGF gene was integrated into the L-chain locus through homologous recombination. Project supported by the Scientific Research Foundation for Returned Overseas Chinese Scholars, Education Ministry of China and the Natural Science Foundation of Zhejiang Province (No. 301306), China  相似文献   

8.
Plastids of nongreen tissues import carbon as a source of biosynthetic pathways and energy, and glucose 6-phosphate is the preferred hexose phosphate taken up by nongreen plastids. A cDNA clone encoding glucose 6-phosphate/phosphate translocator (GPT) was isolated from a cDNA library of immature seeds of rice and named asOsGPT. The cDNA has one uninterrupted open reading frame encoding a 42 kDa polypeptide possessing transit peptide consisting of 70 amino acid residues. TheOsGPT gene maps on chromosome 8 of rice and is linked to the quantitative trait locus for 1000-grain weight. The expression ofOsGPT is mainly restricted to heterotrophic tissues. These results suggest that glucose 6-phosphate imported viaGPT can be used for starch biosynthesis in rice nongreen plastids. Project supported by National Natural Scienc Foundation of China (No.39830250) and Natural Science Foundation of Zhejiang Province (No.2A0106), China. The nucleotide sequence data will appear in the GenBank under accession number AF375053.  相似文献   

9.
Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO2 extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50°C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield flavonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops. Project (No. Y304203) supported by the Natural Science Foundation of Zhejiang Province, China  相似文献   

10.
INTRODUCTION In the past 30 years, much progress has been achieved in thermoacoustic research (Backhaus and Swift, 1999; Garrett et al., 1993; Zhou and Matsubara,1998). However, most of them were still at laboratory scale. Aiming for industrial applications, recent re-searches began to pay attention to larger or smaller scale systems. The problem of heat dissipation from miniature high-tech products (say ICs, MEMS) at-tracts more attention due to the higher heat flux ac-companying th…  相似文献   

11.
In this letter, we introduce a novel passive transmission line of negative refractive index （i.e., left-handedness） based on identical symmetrical lattice type structures [thus called ＂lattice type transmission line＂ （LT-TL）]. The dispersion characteristic and the transmission response of the proposed LT-TL are analyzed. While all the other left-handed passive transmission lines are of high pass, the present passive left-handed transmission line is of low pass. Compared with a conventional transmission line, the LT-TL has a phase shift of 180° in the entire wide pass-band.  相似文献   

12.
INTRODUCTION In recent years theory of extending modules and rings has come to play an important role in the theory of rings and modules. A module is called an extending module (or CS-module) if every submodule is essen- tial in a direct summand, or equivalently, every closed submodule is a direct summand. Although this gen- eralization of injectivity is extremely useful, it does not satisfy some important properties. For example, direct sums of extending modules need not be ex- tending;…  相似文献   

13.
Objective: To observe the difference of androgen and inflammatory cytokines level in atherosclerosis and analyse their relations. Method: Both carotid arteries and arteries of lower extremity were subjected to ultrasonic examination by Doppler's method. Those with much atheromatous plaque formation were ranged into case group, and those with normal result formed control group. Total, free testosterone and estradiol were assayed by radioimmunoassay. C reactive protein (CRP) was assayed by nepheloturbidity. Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Interleukin-18 (IL-18), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were assayed by ELISA. The mean difference between two groups and the correlation between free testosterone and cytokines were analysed. Results: Free testosterone was (6.337±3.371) pg/L in case group and (11.375±4.733) pg/L in control group,P<0.01. No differences were found in total testosterone and estradiol. CRP was (27.294±10.238) mg/L in case group and (12.843±6.318) mg/L in control group,P<0.01. IL-6 was (41.700±31.385) pg/L in case group and (25.396±20.772) pg/L in control group,P<0.05. IL-8 was (89.249±58.357) pg/L in case group and (67.873±31.227) pg/L in control group,P<0.05. sICAM-1 was (470.491±134.078) pg/L in case group and (368.487±97.183) pg/L in control group,P<0.01.sVCAM-1 was (537.808±213.172) pg/L in case group and (457.275±157.273) pg/L in control group,P<0.05. There were no differences in TNF-α, IL-10 and IL-18. Correlation analysis showed that FT (free testosterone) had negative correlation with CRP, IL-6 and sICAM-1. Among them FT had well correlation with CRP, correlation index was −0.678. Conclusion: Free testosterone was in negative correlation with atherosclerosis in old-age male. Free testosterone may have the role of anti-atherosclerosis, and this effect was not achieved by its transformation to estradiol. Low free testosterone level was followed by increased level of inflammatory cytokines. Low free testosterones coexist with inflammation and they both affect the process of atherosclerosis in old-age male. Project (No. 2003B045) supported by the Health Bureau of Zhejiang Province, China  相似文献   

14.
INTRODUCTION On-road vehicles are responsible for a signifi-cant and rapidly increasing portion of the air pollution in the urban areas of China due to rapid growth of motor vehicle population. The State Environmental Protection Administration (SEPA) of China has identified motor vehicles emissions as the major source of urban air pollution in China (SEPA, 2004). As of 2004, on-road vehicles were estimated to con-tribute over 50% of the nitrogen oxides (NOx) to large city’s emissi…  相似文献   

15.
This paper proposes novel multi-layer neural networks based on Independent Component Analysis for feature extraction of fault modes. By the use of ICA, invariable features embedded in multi-channel vibration measurements under different operating conditions (rotating speed and/or load) can be captured together. Thus, stable MLP classifiers insensitive to the variation of operation conditions are constructed. The successful results achieved by selected experiments indicate great potential of ICA in health condition monitoring of rotating machines. Project supported by the National Natural Science Foundation (No. 50205025) and the Natural Science Foundation of Zhejiang Province (No. 5001004).  相似文献   

16.
The dense granule protein 4 (GRA4) is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3.1-GRA4 (pGRA4), encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine (PC), 8 mmol/L dioleoyl phosphatidylethanolamine (DOPE), and 4 mmol/L 1,2-diodeoyl-3-(trimethylammonium) propane (DOTAP). C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay (ELISA) of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon (IFN)-γ and interleukin (IL)-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii. Project supported by the Science Foundation of the Health Bureau of Zhejiang Province, China (Nos. 2003QN003 and 2005A001) and the Science Foundation of the Science and Technology Department of Zhejiang Province, China (No. 2006C13022)  相似文献   

17.
INTRODUCTION Monocrystalline SBN (Strontium barium nio-bium, SrxBa1?xNb2O6, denoted SBNx?100, where 0.25≤x≤0.75) solid solution, is currently being inves-tigated as potential material for many micro-device applications, such as piezoelectric infrared detectors, piezoelectric, electro-optic modulators, and holo-graphic storage (Koch et al., 1998), because SBN has one of the largest known linear electro-optic coeffi-cients (r33=1300 pm/V for SBN75), two orders of magnitude larger th…  相似文献   

18.
On generalized extending modules   总被引：1，自引：0，他引：1  
A module M is called generalized extending if for any submodule N of M, there is a direct summand K of M such that N≤K and K/N is singular. Any extending module and any singular module are generalized extending. Any homomorphic image of a generalized extending module is generalized extending. Any direct sum of a singular (uniform) module and a semi-simple module is generalized extending. A ring R is a right Co-H-ring if and only if all right R modules are generalized extending modules.  相似文献   

19.
Using texture synthesis in fractal pattern design   总被引：2，自引：0，他引：2  
INTRODUCTIONIn the last two decades, research on fractal ge-ometry has received much attention for its theoretical significance and practical applications. Pattern design based on fractal geometry is an important application area of fractal techniques in the textile industry (Wang, 2003). Computer aided pattern design involves the de-sign of textures and colors in the pattern. The source of textures is rich. All kinds of objects and scenery including man-made abstract objects can be used…  相似文献   

20.
Influence of input acoustic power on regenerator＇s performance   总被引：2，自引：0，他引：2  
Performance of a pulse tube cooler significantly depends on the efficient operation ofits regenerator. Influence of input acoustic power on regenerator＇s performance is simulated and analyzed with simple harmonic analysis method. Given regenerator＇s dimensions and pressure ratio, there is an optimal input acoustic power for achieving a highest coefficient of performance, due to a compromise between relative time-averaged total energy flux in regenerator and relative acoustic power at regenerator＇s cold end. Additionally, optimal dimensions of regenerator are also estimated and presented for different input acoustic powers. The computed optimal diameter obviously increases with increase of input acoustic power, while the optimal length decreases slightly, and as a result, a larger input acoustic power requires a smaller aspect ratio （length over diameter）.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号