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   3640篇
  免费   251篇
  国内免费   11篇
耳鼻咽喉   36篇
儿科学   198篇
妇产科学   67篇
基础医学   495篇
口腔科学   55篇
临床医学   242篇
内科学   701篇
皮肤病学   115篇
神经病学   343篇
特种医学   67篇
外科学   572篇
综合类   82篇
预防医学   262篇
眼科学   66篇
药学   360篇
  2篇
中国医学   18篇
肿瘤学   221篇
  2023年   32篇
  2022年   86篇
  2021年   135篇
  2020年   64篇
  2019年   96篇
  2018年   114篇
  2017年   87篇
  2016年   104篇
  2015年   87篇
  2014年   108篇
  2013年   165篇
  2012年   211篇
  2011年   209篇
  2010年   125篇
  2009年   95篇
  2008年   153篇
  2007年   178篇
  2006年   144篇
  2005年   151篇
  2004年   98篇
  2003年   121篇
  2002年   105篇
  2001年   68篇
  2000年   86篇
  1999年   83篇
  1998年   31篇
  1996年   23篇
  1995年   19篇
  1993年   20篇
  1992年   59篇
  1991年   53篇
  1990年   25篇
  1989年   40篇
  1988年   42篇
  1987年   41篇
  1986年   34篇
  1985年   32篇
  1984年   24篇
  1983年   32篇
  1982年   28篇
  1979年   20篇
  1976年   25篇
  1975年   28篇
  1974年   27篇
  1973年   23篇
  1972年   18篇
  1971年   27篇
  1970年   30篇
  1969年   25篇
  1968年   18篇
排序方式: 共有3902条查询结果,搜索用时 15 毫秒
81.
Serum aliesterase levels have been estimated in 38 patients with head and neck cancer. The mean value was significantly lower than in controls. The decrease in activity was greater in patients with ulcerative growths and it progressed with advancement in the stage of cancer. With radiotherapy, a progressive and significant increase in serum aliesterase activity was observed. In patients with non-malignant growths the activity was comparable with that in controls.  相似文献   
82.
83.
Dexmedetomidine, a highly selective alpha(2)-adrenoceptor agonist, reduces the requirements for anesthetic, analgesic, sedative, and hypnotic drugs. Dexmedetomidine pharmacokinetics were characterized in healthy subjects after intravenous administration by means of a computer-controlled infusion pump. A series of seven stepwise increasing pseudo-steady-state plasma concentrations were targeted. The influence of cardiac output on the pharmacokinetics was investigated by use of a compartmental modeling approach in which the elimination clearance was characterized as being either cardiac output independent or dependent. At dexmedetomidine concentrations of 0, 0.6, and 1.2 ng/mL, mean (SD) estimated cardiac outputs were 5. 6 (0.85), 5.1 (0.67), and 4.5 (0.83) L/min, and mean (SD) clearances were 40 (10), 38 (9.0), and 35 (8.5) L/h, respectively. Dexmedetomidine V(SS) and elimination half-life were 72 (19) L and 1. 9 (0.62) h, respectively. The approximately 3 to 19% decrease in cardiac output observed within the anticipated therapeutic range of 0.3 to 1.2 ng/mL was similar to that observed for clonidine. The decrease in cardiac output with increasing plasma concentrations of dexmedetomidine resulted in a corresponding decrease in drug elimination clearance of < or =12% within the therapeutic range; however, this decrease in dexmedetomidine clearance is likely not clinically relevant.  相似文献   
84.
Role of curcumin in idiopathic inflammatory orbital pseudotumours   总被引:2,自引:0,他引:2  
The present report, describes for the first time the clinical efficacy of curcumin, the active constituent of rhizomes of Curcuma longa, in the treatment of patients suffering from idiopathic inflammatory orbital pseudotumours. Curcumin was administered orally at a dose of 375 mg/3 times/day orally for a period of 6-22 months in eight patients. They were followed up for a period of 2 years at 3 monthly intervals. Five patients completed the study, out of which four recovered completely and in one patient the swelling regressed completely but some limitation of movement persisted. No side effect was noted in any patient and there was no recurrence. It is suggested that curcumin could be used as a safe and effective drug in the treatment of idiopathic inflammatory orbital pseudotumours.  相似文献   
85.
The nature of gene action for biomass yield and tropane alkaloid content was ascertained through diallel analysis in Egyptian henbane, HYOSCYAMUS MUTICUS L. Dominance variation was preponderant over additive genetic variance, dominance being in the overdominance range for both traits. On an overall basis, recessive alleles had a positive (i.e. increasing) effect on both the characters. However, the positive or negative effects of recessive or dominant alleles were genotype-specific. Hence, transgressive breeding was suggested for isolating segregants with dominant alleles for herb yield and with recessives for alkaloid content so as to achieve overall high yields of tropane alkaloid per unit area.  相似文献   
86.
Because of the importance of central nervous system (CNS) functions to productive capacity and quality of life, biomarkers of these functions will play a key role in evaluating the success of interventions targeting aging processes. The CNS biomarkers may also be useful for predicting aging in other systems and in the organism as a whole. Age-related behavioral changes, the products of CNS aging, have content and predictive validity with respect to human functional capacities and may, therefore, represent important "neurobehavioral" markers of functional aging. This article presents a discussion of some behavioral paradigms which are currently being considered as neurobehavioral biomarkers of aging in mice and the experimental approaches being employed in the assessment of their validity. Studies conducted in the authors' laboratory using dietary restriction and genetic comparisons to evaluate the validity of neurobehavioral biomarkers have revealed several methodological concerns, and hypothetical and empirical examples of these pitfalls are described and discussed. In spite of those concerns, it is concluded that approaches to validity using genetic comparisons and dietary restriction can be successfully implemented and should ultimately lead to identification of valid and useful neurobehavioral biomarkers of aging.  相似文献   
87.
We describe here two cases, one male and one female, both age 40 years, with visceral leishmaniasis and HIV-1 co-infection. The female patient had features of Koch's abdomen. The male patient had features of tuberculous lymphadenitis and bilateral pleural effusion more marked on the right side. Both were treated with highly active antiretroviral therapy, antituberculous drugs, antibiotics, antifungal medicine (fluconazole) and miltefosine. Both patients showed marked improvement with therapy.  相似文献   
88.
89.
90.

Background  

Workers working close to salt milling plants may inhale salt particles floating in the air, leading to a rise in plasma sodium, which, in turn, may increase the blood pressure and the risk of hypertension.  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