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   2591篇
  免费   82篇
耳鼻咽喉   7篇
儿科学   53篇
妇产科学   61篇
基础医学   146篇
口腔科学   53篇
临床医学   639篇
内科学   743篇
皮肤病学   81篇
神经病学   56篇
特种医学   1篇
外科学   275篇
综合类   4篇
一般理论   18篇
预防医学   159篇
眼科学   15篇
药学   308篇
肿瘤学   54篇
  2017年   13篇
  2016年   35篇
  2015年   42篇
  2014年   41篇
  2013年   80篇
  2012年   22篇
  2011年   15篇
  2010年   82篇
  2009年   97篇
  2008年   28篇
  2007年   25篇
  2006年   34篇
  2005年   12篇
  2004年   11篇
  2003年   20篇
  2002年   17篇
  2001年   53篇
  2000年   19篇
  1999年   99篇
  1998年   123篇
  1997年   174篇
  1996年   158篇
  1995年   127篇
  1994年   106篇
  1993年   104篇
  1992年   108篇
  1991年   88篇
  1990年   78篇
  1989年   80篇
  1988年   81篇
  1987年   63篇
  1986年   62篇
  1985年   45篇
  1984年   47篇
  1983年   45篇
  1982年   37篇
  1981年   53篇
  1980年   36篇
  1979年   35篇
  1978年   33篇
  1977年   28篇
  1976年   32篇
  1975年   22篇
  1974年   9篇
  1973年   10篇
  1972年   12篇
  1971年   17篇
  1966年   12篇
  1958年   9篇
  1954年   11篇
排序方式: 共有2673条查询结果,搜索用时 15 毫秒
101.
We report a patient without immune compromise with infection of an automatic internal cardiac defibrilla- tor patch due to Aspergillus fumigatus presenting 8 years after implantation. The mechanism of infection was unknown, but symptoms began 1 month after laser uvulopalatopharyngoplasty was performed for sleep apnea. The patches were surgically removed and the patient was treated sequentially with amphotericin B and itraconazole. He remains without evidence of infection 12 months after the completion of therapy.  相似文献   
102.
We have investigated the influence of antithyroid drugs (methimazole and propylthiouracil) and sodium iodide on the expression of major histocompatibility (MHC) class II antigen expression in human and rat thyroid cells. While methimazole and propylthiouracil significantly inhibited lectin-induced MHC class II (HLA-DR) antigen in crude human thyroid monolayer preparations these drugs had no influence on gamma-interferon induction of class II antigens in similar cell preparations. Hence, antithyroid drugs probably had a direct effect on thyroid monolayer T cells which are known to effect the lectin induction of MHC class II antigen via T-cell secretion of the cytokine, gamma-interferon (IF). Sodium iodide, similarly, had no direct influence on human thyroid cell MHC class II antigen expression induced by gamma-IF. However, iodide significantly inhibited the gamma-IF-induced expression of MHC class II antigens in a proliferating rat thyroid cell clone derived from FRTL-5 cells (clone 1B-6). In the rat thyroid cell clone this antagonistic action appeared to be exerted via inhibition of TSH-induced proliferation. These data add further support to the multifactorial nature of the profound immunosuppressive influence of antithyroid drugs in autoimmune thyroid disease and experimental thyroiditis. In contrast, iodides may have a major, and often overlooked, influence on thyroid cell proliferation and antigen expression.  相似文献   
103.
104.
Abstract— The subcutaneous absorption and consequent tissue distribution of interferon g was studied in an anaesthetized rat model. Interferon g showed a biphasic disappearance profile from a solution in a subcutaneous absorption cell. Both the initial rapid distribution phase and slower removal phase followed first order kinetics. The steady-state clearance of interferon g from the cell was 1·41 ± 0·38 × 10?3 mL min?1, and the absorption half-life (t½) was 3·8 ± 1·1 h (n = 4). Noradrenaline did not significantly alter either the clearance or absorption of interferon g (1·18 ± 0·44 × 10?3 mL min?1 P > 0·05, absorption t½ 4·96 ± 1·9 h, P > 0·05). Given that the clearance of smaller solutes, such as tritiated water, is significantly reduced when noradrenaline is coadministered, it is suggested that interferon g is removed via the lymphatic system rather than by the local blood supply. The amount of interferon g recovered in the plasma, urine and muscle is minimal relative to other solutes where the recovery is almost complete.  相似文献   
105.
The acetyl-derivative of the biologically active C-terminal 7-peptide portion of cholecystokinin (CCK), N-acetyl-O-sulfate-L-tyrosyl-L-methionyl-glycyl-L-tryptophyl-L-methionyl-L-aspanyl-L-phenylalanine amide was prepared by the condensation of 2-peptide segments with 1-isobutyloxycarbonyl-2-isobutyloxy-1,2-dihydroquinoline as coupling reagent. The N-terminal residue, tyrosine, was incorporated by the active ester method. The same 7-peptide was prepared also by stepwise chain-lengthening, starting with the C-terminal residue. The 9-fluorenylmethyloxycarbonyl group was applied for the protection of α-amino functions. In the release of amylase from acinar cells of the pancreas of guinea pigs, the acetyl-7-peptide amide was about 3 times more potent than CCK 27–33 and equal in potency to CCK 26–33. The new derivative strongly stimulated the contraction of the in situ guinea pig gall bladder.  相似文献   
106.
107.
ABSTRACT: A 6-year-old boy developed a sty of his right eye lid. This was proven to be caused by Trichophyton mentagrophytes which was also recovered from a pet guinea pig.  相似文献   
108.
The epidemiology of congenital abnormalities is reviewed and the data available in the Registrar General's Annual Reviews for England and Wales from 1848 to 1967 are analysed statistically. The time and place of reported epidemics of spina bifida and anencephalus are tabulated. It is concluded that the pattern of epidemics of dysraphism in time and place is inconsistent with a viral aetiology, and it is suggested that a proportion of embryos may be genetically susceptible to an antimetabolite present in a food under certain conditions of preservation, preparation or storage.  相似文献   
109.
Since an increasing number of patients with cystic fibrosis now reach adolescence and adulthood, more will be treated by general physicians. Since 1953 approximately 200 patients have been cared for in this unit, and in January, 1967, 31 were over 14 years of age; five of these have since died, and their modes of death (chest infection and respiratory failure, three; moderate chest disease, massive hæmoptysis, one; mild chest disease and progressive liver disease, one) are considered. The clinical state of the survivors varies greatly and allows discussion of the natural history of the disorder. The well-being of patients depends both on the intrinsic severity of the manifestations of the disease and the efficacy of treatment. With careful attention to chest disease most of these older patients manage to lead relatively active lives and are in most instances gainfully employed.  相似文献   
110.
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