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   5376篇
  免费   341篇
  国内免费   22篇
耳鼻咽喉   48篇
儿科学   181篇
妇产科学   78篇
基础医学   672篇
口腔科学   123篇
临床医学   514篇
内科学   1150篇
皮肤病学   42篇
神经病学   295篇
特种医学   83篇
外科学   475篇
综合类   246篇
一般理论   3篇
预防医学   722篇
眼科学   163篇
药学   588篇
中国医学   87篇
肿瘤学   269篇
  2024年   9篇
  2023年   85篇
  2022年   318篇
  2021年   419篇
  2020年   200篇
  2019年   233篇
  2018年   242篇
  2017年   180篇
  2016年   164篇
  2015年   158篇
  2014年   222篇
  2013年   285篇
  2012年   403篇
  2011年   409篇
  2010年   186篇
  2009年   127篇
  2008年   254篇
  2007年   223篇
  2006年   204篇
  2005年   173篇
  2004年   168篇
  2003年   154篇
  2002年   138篇
  2001年   93篇
  2000年   73篇
  1999年   72篇
  1998年   32篇
  1997年   50篇
  1996年   24篇
  1995年   24篇
  1994年   25篇
  1993年   22篇
  1992年   36篇
  1991年   33篇
  1990年   33篇
  1989年   22篇
  1988年   32篇
  1987年   18篇
  1986年   14篇
  1985年   18篇
  1984年   13篇
  1983年   14篇
  1982年   9篇
  1980年   16篇
  1978年   10篇
  1976年   10篇
  1975年   13篇
  1972年   8篇
  1971年   9篇
  1970年   9篇
排序方式: 共有5739条查询结果,搜索用时 15 毫秒
81.
82.
M. S. Islam  I. Zimmermann  W. T. Ulmer 《Lung》1975,152(4):281-289
Unilateral application of histamine in one segmental bronchus potentiated the airway resistance increase caused by ACH challenge of the bronchial tree. Unilateral or contralateral blockade of the N. vagus reduces the severity of the reaction by about 70% of the values before the blockade. The arterial blood gases were not influenced by the unilateral blockade of the N. vagus. The decrease of the arterial oxygen pressure following the ACH induced bronchoconstriction was not changed by the unilateral vagotomy. The breathing patterns change by unilateral vagus blockade: Tidal volume increases by about 50% and the breathing rate decreases by about 30%. The heart rates were remained unchanged.  相似文献   
83.
84.
85.
86.
87.
Shigellosis is a worldwide disease, characterized by abdominal pain, fever, vomiting, and the passage of blood‐ and mucus‐streaked stools. Rhesus monkeys and other primates are the only animals that are naturally susceptible to shigellosis. A suitable animal model is required for the pre‐clinical evaluation of vaccines candidates. In this study, the minimal dose of Shigella dysenteriae1 1617 strain required to produce dysentery in four of five (80% attack rate) monkeys using an escalating dose range for three groups [2 × 108, 2 × 109 and 2 × 1010 colony forming unit (CFU)] was determined. In addition, the monkeys were re‐infected. The identified optimal challenge dose was 2 × 109 CFU; this dose elicited 60% protection in monkeys when they were re‐challenged with a one log higher dose (2 × 1010 CFU). The challenge dose, 2 × 1010 CFU, produced severe dysentery in all monkeys, with one monkey dying within 24 h, elicited 100% protection when re‐challenged with the same dose. All monkeys exhibited immune responses. This study concludes that the rhesus monkey model closely mimics the disease and immune response seen in humans and is a suitable animal model for the pre‐clinical evaluation of Shigella vaccine candidates. Prior infection with the 1617 strain can protect monkeys against subsequent re‐challenges with homologous strains.  相似文献   
88.
Campylobacter jejuni is the most important cause of antecedent infections leading to Guillain–Barré syndrome (GBS) and Miller Fisher syndrome (MFS). The objective of the present study was to define the genetic diversity, population structure, and potential role of poultry in the transmission of Campylobacter to humans in Bangladesh. We determined the population structure of C. jejuni isolated from poultry (n?=?66) and patients with enteritis (n?=?39) or GBS (n?=?10). Lipooligosaccharide (LOS) typing showed that 50/66 (76 %) C. jejuni strains isolated from poultry could be assigned to one of five LOS locus classes (A–E). The distribution of neuropathy-associated LOS locus classes A, B, and C were 30/50 (60 %) among the typable strains isolated from poultry. The LOS locus classes A, B, and C were significantly associated with GBS and enteritis-related C. jejuni strains more than for the poultry strains [(31/38 (82 %) vs. 30/50 (60 %), p?p?C. jejuni isolated from humans and poultry. There seems to be a lack of overlap between the major human and chicken clones, which suggests that there may be additional sources for campylobacteriosis other than poultry in Bangladesh.  相似文献   
89.
Objective:To evaluate the antidiabetic and antioxidant potential of Emblica officinalis(E.officinalis)fruit on normal and type 2 diabetic rats.Methods:Type 2 diabetes was induced into the male Long-Evans rats.The rats were divided into nine groups including control groups receiving water,type 2 diabetic controls,type 2 diabetic rats treated with glibenclamide(T2GT)and type 2diabetic rats treated with aqueous extract of fruit pulp of E.officinalis.They were fed orally for8 weeks with a single feeding.Blood was collected by cutting the tail tip on 0 and 28 days and by decapitation on 56 day.Packed red blood cells and serum were used for evaluating different biochemical parameters.Results:Four weeks administration of aqueous extract of E.officinalis improved oral glucose tolerance in type 2 rats and after 8 weeks it caused significant(P0.007)reduction in fasting serum glucose level compared to 0 day.Triglycerides decreased by 14%but there was no significant change in serum ALT,creatinine,cholesterol and insulin level in any group.Furthermore,reduced erythrocyte malondialdehyde level showed no significant change(P0.07)but reduced glutathione content was found to be increased significantly(P0.05).Conclusions:The aqueous extract of E.officinalis has a promising antidiabetic and antioxidant properties and may be considered for further clinical studies in drug development.  相似文献   
90.
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