首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   649篇
  免费   21篇
  国内免费   44篇
耳鼻咽喉   1篇
儿科学   13篇
妇产科学   6篇
基础医学   64篇
口腔科学   21篇
临床医学   69篇
内科学   106篇
皮肤病学   4篇
神经病学   41篇
特种医学   18篇
外科学   110篇
综合类   24篇
预防医学   105篇
眼科学   15篇
药学   76篇
肿瘤学   41篇
  2023年   6篇
  2022年   13篇
  2021年   16篇
  2020年   13篇
  2019年   14篇
  2018年   25篇
  2017年   8篇
  2016年   9篇
  2015年   19篇
  2014年   17篇
  2013年   33篇
  2012年   40篇
  2011年   59篇
  2010年   37篇
  2009年   23篇
  2008年   33篇
  2007年   65篇
  2006年   39篇
  2005年   44篇
  2004年   43篇
  2003年   27篇
  2002年   31篇
  2001年   4篇
  2000年   12篇
  1999年   4篇
  1998年   10篇
  1997年   8篇
  1996年   3篇
  1995年   9篇
  1994年   5篇
  1993年   7篇
  1992年   5篇
  1991年   8篇
  1990年   7篇
  1989年   2篇
  1988年   4篇
  1985年   1篇
  1984年   2篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有714条查询结果,搜索用时 31 毫秒
1.
2.
糖尿病妇科手术92例的围手术期处理   总被引:1,自引:0,他引:1  
朱文昭 《医学争鸣》2005,26(4):367-367
2002-01/2004-01Ⅱ型糖尿病(DM)妇科手术患92例,年龄31~73(平均53.4)岁.有明确DM病史53例.病程1/12~21(平均6.9)a,入院后新诊断的DM39例空腹血糖为5.9—18.0(平均9.6)mmol/L,餐后血糖为9.3—22.6(平均16.5)mmol/L,术前准备时间平均为6.4d,术后住院时间平均为11.4d,术前有并存症72例.随机抽取同期住院非DM妇科手术92例,年龄22~65(平均41.5)岁,  相似文献   
3.
The aim of this study was to examine hormonal and metabolic changes in a group of 18 professional male cyclists ((.)VO(2)max 69.9 [95 % CI 64.9 to 74.9] mL x kg(-1) x min(-1) ) during two successive periods of adapted intensive training. The second training period included 4 days of cycling competition. Intensity was increased while volume was decreased in the second training. Anthropometric data were collected before and at the end of the two training periods. Venous blood samples were taken in a basal state before the two training sessions and after each training session. Serum concentrations of cortisol (C), testosterone (T), dehydroepiandrosterone sulfate (DHEAs), and catecholamines were determined as well as branched-chain amino acids (valine, leucine, isoleucine) (BCAA) and free fatty acids (FFAs). At the end of the two training periods, the subjects lost fat mass whereas mean body mass was unchanged. The T/C ratio was reduced transiently after the first training session (45.90 %), while DHEAs/C remained unchanged. T/C and DHEAs/C were significantly increased after the second training session compared to the first (48.40 and 97.18 %, respectively). Catecholamines and FFAs were unchanged. The significant increase in BCAA levels after the second training session was of note as it might constitute a "store shape" of amino acids in anticipation of future intense training loads. Based on the responses of testosterone, DHEAs, and cortisol, and on the training-induced increase in BCAA, there appeared to be hormonal and metabolic adaptation despite the inherent psychological stress of competition.  相似文献   
4.
5.
Analysis of the HIV-1 V3 quasispecies present in an individual at the time of seroconversion was carried out. The polymerase chain reaction (PCR) was used to amplify proviral HIV-1 DNA extracted from peripheral blood mononuclear cells from a patient who was viraemic (p24 = 15 pg/ml) and had an equivocal HIV-1 antibody status. The PCR products were cloned and the DNA sequence determined for 15 clones. These data showed that the V3 region contained only limited sequence heterogeneity with a major variant accounting for 66% of the protein quasispecies present. The protein sequence of the principal neutralising domain on all species contained the relatively rare GPGKTL motif rather than GPGRAF. The relevance of these data for early stages of HIV infection are discussed.  相似文献   
6.
We are elaborating on the kinetics and mechanisms of septic rabbit liver to de novo biosynthesize acute-phase response (APR) proteins under in vitro conditions of deepening ischemia in reference to their in vivo prevalence in serum and cerebrospinal fluids (CSF) collected at predetermined times. The significance of the data is interpreted as relevant to grafting cadaveric liver into end-stage liver diseased patients and APR-induced ischemic heart diseases (IHD). Hepatic APR was induced by CCl(4)-intubation, and the administration of cholera toxin (CT) or scorpion venom (SV), or both, to rabbits. Hepatic functional efficiency, in terms of biosynthesis of APR proteins in closed circuit perfusion of the isolated intoxicated liver with oxygenated saline or L-15 media paralleled the two-dimensional immunoelectrophoresis (2D-IEP) spectrum of APR serum proteins at time of liver isolation. We are suggesting: (a) in vitro biosynthesis of plasma proteins by isolated perfused liver is the result of in vivo decoded and retained APR inflammatory signals; and (b) decoded inflammatory signals are expressed not withstanding the perfusate's organic composition. Furthermore, 90 min of ischemic perfusion in saline or L-15 medium precipitated mitochondrial aberrations which resulted in further deterioration of de novo biosynthesis of APR plasma proteins. Regardless of the nature of the inflammatory stimuli, mitochondrial aberrations rendered the perfused organ a biologically inert tissue mass that was incapable of resuming biological function upon perfusion with oxygenated L-15 medium. This is most likely due to ischemia-induced irreversible hepatic necrosis. Thus, in vitro aberrations of mitochondrial function(s) critically limit the capability of the isolated liver to resume its organic function to sustain biosynthesis of de novo plasma proteins. Extrapolation of these results to the surgical management of end-stage liver diseases points to the importance of the status and the handling protocol(s) of the cadaver donor liver prior to successful grafting. We conclude that although histology of a cadaver liver may reveal well-preserved hepatic cellular organelles with at least minimal intra- and intercellular communication required for viable hepatic function, we deem it essential to further define acceptable minimal capabilities to de novo biosynthesize plasma proteins by a cadaver liver as a measure of its functional viability and suitability for transplantation. Ultimately, this measure may improve the success of liver transplants with minimal surgical and drug interventions.  相似文献   
7.
8.
To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1 (CN)) in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA (1.3 kb) was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows: BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting.  相似文献   
9.
Plackett–Burman randomization method is a conventional tool for variables randomization aiming at optimization. Bacterial Ghosts (BGs) preparation has been recently established using methods other than the E lysis gene. The protocol has been based mainly on using critical concentrations from chemical compounds able to convert viable cells to BGs. The Minimum Inhibition Concentration (MIC) and the Minimum Growth Concentration (MGC) were the main guide for the BGs preparation. In this study, Escherichia coli JM109 DEC has been used to produce the BGs following the original protocol. The study contained a detail protocol for BGs preparation that could be used as a guide.  相似文献   
10.
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