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   2558篇
  免费   149篇
  国内免费   4篇
耳鼻咽喉   46篇
儿科学   128篇
妇产科学   48篇
基础医学   261篇
口腔科学   110篇
临床医学   187篇
内科学   611篇
皮肤病学   25篇
神经病学   184篇
特种医学   56篇
外科学   413篇
综合类   49篇
预防医学   109篇
眼科学   65篇
药学   233篇
中国医学   12篇
肿瘤学   174篇
  2023年   18篇
  2022年   35篇
  2021年   76篇
  2020年   55篇
  2019年   62篇
  2018年   91篇
  2017年   86篇
  2016年   66篇
  2015年   77篇
  2014年   112篇
  2013年   139篇
  2012年   212篇
  2011年   221篇
  2010年   128篇
  2009年   102篇
  2008年   192篇
  2007年   174篇
  2006年   147篇
  2005年   129篇
  2004年   116篇
  2003年   102篇
  2002年   91篇
  2001年   27篇
  2000年   13篇
  1999年   15篇
  1998年   19篇
  1997年   11篇
  1996年   15篇
  1995年   11篇
  1994年   10篇
  1993年   8篇
  1992年   7篇
  1991年   12篇
  1990年   22篇
  1989年   9篇
  1988年   7篇
  1987年   8篇
  1986年   6篇
  1985年   6篇
  1984年   6篇
  1983年   8篇
  1982年   5篇
  1981年   8篇
  1980年   8篇
  1979年   5篇
  1978年   3篇
  1976年   6篇
  1975年   3篇
  1973年   4篇
  1972年   5篇
排序方式: 共有2711条查询结果,搜索用时 15 毫秒
1.
INTRODUCTIONThis study aimed to investigate the therapeutic response to injected human umbilical cord blood mesenchymal stem cells (UCBMSCs) among albino rats with streptozotocin (STZ)-induced diabetes mellitus.METHODSControl group (GI; n = 25) rats were fed with standard rat diet. Rats with STZ-induced diabetes mellitus without (GII; n = 25) and with (GIII; n = 25) differentiated human UCBMSCs implantation were the test groups. Rats were sacrificed in Week 11 following implantation. Liver biopsies were sectioned and stained in order to highlight both the presence and function of impregnated cells in the liver tissue.RESULTSHaematoxylin and eosin-stained sections in GI and GII rats showed normal liver architecture while GIII rats showed presence of cell clusters inside the liver tissue and around the central veins. Cell clusters with blue cytoplasm were present in sections in GIII rats but absent in GI and GII rats, indicating the presence of injected differentiated human UCBMSCs. The anti-human insulin immunostaining of GIII rats showed clusters of cells within the liver parenchyma and around central veins, indicating that these cells were active and secreting insulin.CONCLUSIONUCBMSCs are proficient in differentiating into insulin-producing cells in vivo under specific conditions and, when transplanted into the liver of albino rats with STZ-induced diabetes mellitus, were able to secrete insulin and partially control the status of diabetes mellitus in rats.  相似文献   
2.
3.
A 17-year-old man presented with signs of peritonitis. Laparotomy revealed gangrene of the stomach without obvious cause. The patient underwent total gastrectomy with esophago-jejunal anastomosis with formation of jejunal pouch. Bacterial culture of the peritoneal fluid grew Strept. pyogenes and E. coli. The patient was discharged on day 21 after a stormy postoperative course.  相似文献   
4.
5.
OBJECTIVES: The purpose of this study was to determine quality of life (QOL) and exercise performance (EP) in patients with persistent atrial fibrillation (AF) converted to sinus rhythm (SR) compared with those remaining in or reverting to AF. BACKGROUND: Restoration of SR in patients with AF improving QOL and EP remains controversial. METHODS: Patients with persistent AF were randomized double-blind to amiodarone, sotalol, or placebo. Those not achieving SR at day 28 were cardioverted and classified into SR or AF groups at 8 weeks (n = 624) and 1 year (n = 556). The QOL (SF-36), symptom checklist (SCL), specific activity scale (SAS), AF severity scale (AFSS), and EP were assessed. RESULTS: Favorable changes were seen in SR patients at 8 weeks in physical functioning (p < 0.001), physical role limitations (p = 0.03), general health (p = 0.002), and vitality (p < 0.001), and at 1 year in general health (p = 0.007) and social functioning (p = 0.02). Changes in the scores for SCL severity (p = 0.01), functional capacity (p = 0.003), and AFSS symptom burden (p < 0.001) at 8 weeks and in SCL severity (p < 0.01) and AF symptom burden (p < 0.001) at 1 year showed significant improvements in SR versus AF. Symptomatic patients were more likely to have improvement. The EP in SR versus AF was greater from baseline to 8 weeks (p = 0.01) and to 1 year (p = 0.02). The EP correlated with physical functioning and functional capacity except in the AF group at 1 year. CONCLUSIONS: In patients with persistent AF, restoration and maintenance of SR was associated with improvements in QOL measures and EP. There was a strong correlation between QOL measures and EP.  相似文献   
6.
Role of Embolisation in preoperative management of Nasopharyngeal angiofibroma is well established in present day therapeutic modalities. An improvised technique i.e., subselective embolisation has been provided by Interventional radiologists to fortify the therapeutic results. This study compares the final outcome of seven cases, four of which were embolised pre operatively. Each case was dealt with varying surgical approaches.  相似文献   
7.
At present, polymers represent a class of ubiquitous materials. They are being used for a multitude of purposes and the almost inexhaustible varieties of molecular architecture that macromolecular materials can possess provides the possibility for a myriad of applications. Because of the increased interest being shown in the macromolecules by the pharmaceutical industry for the fabrication of drug delivery systems, numerous polymers have been synthesized and successfully used in drug delivery devices. The necessary conditions for developing the concept of pharmaceutically applicable polymers depend upon delineating a detailed knowledge of the relationship between the structure and properties of polymer networks. A number of polymers have been studied systematically from this point of view and there is every indication that the systems described have the potential to become clinically valuable and therefore marketable drug delivery systems. The potential of these promising polymers is still far from being exhausted and there is a strong possibility that many important developments will be forthcoming in this field in the future. In the current review article, polymers for controlled release have been divided into four major categories: diffusion-controlled systems; chemically controlled systems; solvent-activated systems; and magnetically controlled systems. Polymers as drug carriers also have been divided into various subgroups: soluble, biodegradable, mucoadhesive and other polymeric systems. The latter group includes polymers containing pendant bioactive substituents, matrix systems, heparin-releasing polymers, ionic polymers, oligomers and miscellaneous. At an introductory and fundamental level, an overview of these polymers and the materials science for the design of drug delivery systems will be discussed.  相似文献   
8.
This article summarizes the ways in which a clinician should think about medication use in children and describes practical usage of the most frequently used child psychopharmacologic agents.Leena Ranade, M.D., and Aftab Qadir, M.D., were Fellows in Child Psychiatry, State University of New York at Stony Brook at the time of writing this article.  相似文献   
9.
OBJECTIVE: Recent studies of patients with juvenile bipolar disorder report low rates of recovery and high rates of chronicity. However, we lack data on the short-term outcome. This study examines the pattern of recovery from the index episode in an aggressively treated juvenile sample. METHOD: We assessed 25 subjects (< 16 years) with a diagnosis of mania, using the Diagnostic Interview for Children and Adolescents-Revised) (DICA-R), Young Mania Rating Scale (YMRS), and Children's Global Assessment Scale (CGAS) at intake and at 3 and 6 months. We studied the time taken to recover from the index episode, the level of functioning, and the factors predicting them. RESULTS: After 6 months, 24 (96%) subjects had recovered from the index manic episode. The median time to recovery was 27 days. Total episode length was significantly longer among those with previous affective episodes. CONCLUSIONS: The findings suggest that juvenile-onset mania has high rates of recovery and low rates of chronicity. These differences from the existing literature need further exploration.  相似文献   
10.
It was postulated that identification of term (LGA) large for gestational age newborns by the Portland Intrauterine Growth Curve rather than the Colorado Curve would classify a lesser number of neonates as LGA, but would identify the LGA neonates at risk for hypoglycemia. One hundred inborn neonates who plotted LGA on the Colorado Chart were reviewed. Sixty-one infants were LGA on the Portland Chart. Of the 100 infants, 17 were found to have dextrostix less than 45 mg% in the first two hours of life, 15 of these had quantitative blood glucose (BG) test performed. Eleven of the 15 neonates had a BG less than 40 mg%; all 11 hypoglycemic neonates were identified LGA on the Colorado Graph whereas only seven were identified LGA by the Portland Graph. The authors conclude that the Colorado Graph is a better tool in their population than the Portland in identifying term LGA neonates at risk for hypoglycemia.  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