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   1448篇
  免费   70篇
  国内免费   53篇
耳鼻咽喉   34篇
儿科学   22篇
妇产科学   16篇
基础医学   175篇
口腔科学   87篇
临床医学   137篇
内科学   390篇
皮肤病学   15篇
神经病学   89篇
特种医学   153篇
外科学   192篇
综合类   11篇
预防医学   38篇
药学   83篇
肿瘤学   129篇
  2022年   8篇
  2021年   22篇
  2020年   9篇
  2019年   13篇
  2018年   11篇
  2017年   12篇
  2016年   19篇
  2015年   22篇
  2014年   36篇
  2013年   29篇
  2012年   49篇
  2011年   35篇
  2010年   41篇
  2009年   44篇
  2008年   38篇
  2007年   99篇
  2006年   52篇
  2005年   71篇
  2004年   61篇
  2003年   58篇
  2002年   75篇
  2001年   53篇
  2000年   48篇
  1999年   42篇
  1998年   36篇
  1997年   31篇
  1996年   37篇
  1995年   27篇
  1994年   28篇
  1993年   17篇
  1992年   42篇
  1991年   20篇
  1990年   40篇
  1989年   43篇
  1988年   44篇
  1987年   20篇
  1986年   34篇
  1985年   29篇
  1984年   15篇
  1983年   14篇
  1979年   11篇
  1978年   12篇
  1977年   14篇
  1976年   12篇
  1975年   9篇
  1973年   10篇
  1971年   13篇
  1969年   6篇
  1968年   7篇
  1966年   7篇
排序方式: 共有1571条查询结果,搜索用时 15 毫秒
131.
小肠缺血再灌注损伤的研究进展   总被引:9,自引:0,他引:9  
  相似文献   
132.
Calcium channel blockers (CCB) and statins are frequently prescribed for patients with coronary artery disease (CAD) complicated by hypertension and/or hypercholesterolemia. CCB have pleiotropic actions beyond their blood pressure-lowering effect, while statins have pleiotropic actions beyond their cholesterol-lowering effect. We assessed the hypothesis that combined treatment with CCB and statins has additional prognostic benefits resulting from potential additive or synergistic pleiotropic actions of both classes of drugs in the Japanese CAD (JCAD) study population. The JCAD study consisted of 13,812 patients with angiographically demonstrable significant coronary narrowing in at least 1 of 3 major coronary arteries who were followed-up for a mean of 2.7 years (follow-up rate, 88.4%). The primary endpoint of the present study was all cardiovascular events. We compared the event rate between patients receiving neither CCB nor statins and those receiving each drug alone or as a combination treatment using propensity score matching analysis. The rate of all events was 62.8 per 1,000 patient-years in the JCAD study. Kaplan-Meier analysis with the log-rank test showed no statistically significant difference in the event rate in each comparison. In conclusion, there may be no additional prognostic benefit beyond the blood-pressure-lowering and cholesterol-lowering effects in the combined treatment with CCB and statins for angiographically documented CAD patients.  相似文献   
133.
Reward-induced burst firing of dopaminergic neurons has mainly been studied in the primate midbrain. Voltammetry allows high-speed detection of dopamine release in the projection area. Although voltammetry has revealed presynaptic modulation of dopamine release in the striatum, to date, reward-induced release in awakened brains has been recorded only in rodents. To make such recordings, it is possible to use conventional carbon fibres in monkey brains but the use of these fibres is limited by their physical fragility. In this study, constant-potential amperometry was applied to novel diamond microelectrodes for high-speed detection of dopamine. In primate brains during Pavlovian cue-reward trials, a sharp response to a reward cue was detected in the caudate of Japanese monkeys. Overall, this method allows measurements of monoamine release in specific target areas of large brains, the findings from which will expand the knowledge of reward responses obtained by unit recordings.  相似文献   
134.

Background  

Prosthetic design for the use in primary total knee arthroplasty has evolved into designs that preserve the posterior cruciate ligament (PCL) and those in which the ligament is routinely sacrificed (posterior stabilized). In patients with a functional PCL the decision which design is chosen depends largely on the favour and training of the surgeon.  相似文献   
135.
136.
137.
BACKGROUND/AIMS: Although hyperglobulinemia is frequently detected in severe chronic liver diseases (CLD) such as liver cirrhosis (LC), the mechanism for this is still uncertain. Hyperglobulinemia may represent a functional aspect of the liver. METHODOLOGY: The correlation between serum globulin (GLB) level and each of various liver function tests including the indocyanine green (ICG) retention rate at 15 min (ICGR15) was studied using 146 patients with liver dysfunction. The correlations among GLB, IgG and ICGR15 were also studied in other 32 patients with LC, in whom the glycosylation pattern of IgG was determined by enzyme-linked immunosorbent assay to detect terminal galactose (Gal) and neuraminic acid (NA) using biotinylated lectins. RESULTS: GLB level was predominantly correlated with ICGR15 (r = 0.449) among various liver function tests in 146 patients with liver dysfunction. In the 32 patients with LC, strong positive correlations between GLB and IgG (r = 0.875), between GLB and ICGR15 (r = 0.435), and between IgG and ICGR15 (r = 0.557) were evident. The glycosylation pattern of IgG showed that the proportions of both Gal and NA were inversely correlated with serum IgG levels (r = -0.516 and -0.390, respectively) in these patients. Significant decreases of the proportions were found in patients with IgG elevation (> 20 g/L, n = 13). CONCLUSIONS: The correlation between GLB and ICGR15 suggested that hyperglobulinemia is related to a common dysfunction estimated by ICG clearance, which represents mainly the liver's blood flow and removal capacity. The removal of immunoglobulins by the liver may be impaired in patients with severe liver dysfunction because the liver is a major catabolic site for immunoglobulins. The glycation pattern suggested that the proportions of asialo IgG and agalactosyl IgG were increased in the LC patients with IgG elevation possibly by deficient receptor-mediated removal in the liver. Although further investigations will be needed, hyperglobulinemia could be predictive for a certain impaired hepatic function estimated by ICG clearance in severe CLD such as LC.  相似文献   
138.
We previously performed mutant screens in the medaka for defects in gonadal development and identified a mutant of interest in this regard, which was designated as hotei (hot). This mutant manifests a number of remarkable phenotypic abnormalities including: (i) excessive proliferation of germ cells that initiates at around the hatching stage regardless of the genetic sex of the fish; (ii) initiation of premature meiosis in phenotypically male hot homozygotes; (iii) one-half of the hot-homozygous XY fish undergo sex reversal, which accompanies the expression of the female-characteristic aromatase gene in the somatic cells of the gonad; and (iv) in phenotypically female homozygotes, follicular development is arrested at an early stage. We have also performed genetic mapping, chromosome walking, and candidate gene sequencing analysis of hot and demonstrate that the underlying mutation occurs in the recently identified medaka anti-Müllerian hormone (Amh) receptor type II (amhrII) gene. Moreover, this gene was found to be responsible for each of the hot phenotypes, as an amhrII transgene rescues these abnormalities. In addition, the amhrII gene is expressed in the somatic cells of the gonads of both sexes. The phenotypes of the hot homozygotes indicate that there are multiple regulatory functions of the AMH/AMHRII signaling system in the development of the gonad, including the sex-dependent regulation of germ cell proliferation and follicular development. These presumably represent the basic roles of Amh, which precede Müllerian duct evolution during phylogeny.  相似文献   
139.
140.
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