全文获取类型
收费全文 | 2703147篇 |
免费 | 191346篇 |
国内免费 | 5881篇 |
专业分类
耳鼻咽喉 | 37850篇 |
儿科学 | 86873篇 |
妇产科学 | 76257篇 |
基础医学 | 383058篇 |
口腔科学 | 80079篇 |
临床医学 | 238572篇 |
内科学 | 523246篇 |
皮肤病学 | 61493篇 |
神经病学 | 211942篇 |
特种医学 | 103690篇 |
外国民族医学 | 661篇 |
外科学 | 411694篇 |
综合类 | 62965篇 |
现状与发展 | 10篇 |
一般理论 | 934篇 |
预防医学 | 197156篇 |
眼科学 | 65190篇 |
药学 | 200132篇 |
11篇 | |
中国医学 | 6436篇 |
肿瘤学 | 152125篇 |
出版年
2018年 | 28131篇 |
2017年 | 21740篇 |
2016年 | 24115篇 |
2015年 | 27342篇 |
2014年 | 38205篇 |
2013年 | 56868篇 |
2012年 | 77061篇 |
2011年 | 81452篇 |
2010年 | 48363篇 |
2009年 | 45745篇 |
2008年 | 76500篇 |
2007年 | 82469篇 |
2006年 | 83065篇 |
2005年 | 79892篇 |
2004年 | 77444篇 |
2003年 | 74185篇 |
2002年 | 72212篇 |
2001年 | 131795篇 |
2000年 | 134927篇 |
1999年 | 112891篇 |
1998年 | 30605篇 |
1997年 | 27336篇 |
1996年 | 26792篇 |
1995年 | 25573篇 |
1994年 | 23594篇 |
1993年 | 21968篇 |
1992年 | 86600篇 |
1991年 | 84200篇 |
1990年 | 81648篇 |
1989年 | 79006篇 |
1988年 | 72620篇 |
1987年 | 71384篇 |
1986年 | 67799篇 |
1985年 | 64432篇 |
1984年 | 48027篇 |
1983年 | 40941篇 |
1982年 | 23874篇 |
1981年 | 21556篇 |
1979年 | 44557篇 |
1978年 | 31342篇 |
1977年 | 26937篇 |
1976年 | 24705篇 |
1975年 | 27260篇 |
1974年 | 32648篇 |
1973年 | 31676篇 |
1972年 | 29885篇 |
1971年 | 27850篇 |
1970年 | 26133篇 |
1969年 | 24792篇 |
1968年 | 23295篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.
We present evidence to show that monoclonal antibodies to estrogen receptors (ER) in solid phase recognize the secondary estrogen binding sites with moderate to low affinity for estradiol (E2). An excellent quantitative agreement was found in five cytosols between the ER values obtained by the enzyme immunoassay (ER-EIA) and the amount of secondary estrogen binding sites measured by the assay involving dextran-coated charcoal (Clin Chem 1986;32:1496). The immunoreactive protein recognized by the antibody-coated beads, when allowed to react with ER(+) cytosols, is shown to bind [3H]estradiol only when the ligand concentration exceeds 8 nmol/L. Further biochemical and functional characterization of the immunoreactive protein is required to establish similarities/dissimilarities between this protein, high-affinity Type I ER sites, and the secondary sites such as Type II sites. 相似文献
152.
Angiotensin Converting Enzyme Inhibitors: Animal Experiments Suggest a New Pharmacological Treatment for Alcohol Abuse in Humans 总被引:1,自引:0,他引:1
G. Spinosa MSc E. Perlanski Dipl Tech. F. H. H. Leenen MD R. B. Stewart MSc L. A. Grupp DSc 《Alcoholism, clinical and experimental research》1988,12(1):65-70
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans. 相似文献
153.
A mechanistic QSAR study on N-nitrosamines (NA) was performed with the aid of the semiempirical MINDO/3 method. Both the chemical reactivity and the transport in biological medium were taken into account. The parent NA molecules and their first reaction intermediates in the metabolic activation pathway were examined for possible determinants of the relative carcinogenic potency. The correlations found support the previous suggestions concerning the metabolic C alpha radical hydroxylation of NA. The role of transport properties in the early stage of NA biotransformation was also demonstrated. 相似文献
154.
S Hummel J Slapke 《Zeitschrift für die gesamte innere Medizin und ihre Grenzgebiete》1988,43(12):319-323
In any case of acute bronchoconstriction the possibility of an adverse reaction to a drug should be considered. In many of such side reactions no allergic mechanism can be detected. Therefore, they are included into the category of pseudoallergic reactions (PAR). The clinically most important form of drug-induced bronchial asthma, analgesics asthma, belongs to this PAR group. A further risk for asthmatics are intravenous applications of contrast-media for roentgenography which in about 15% induce a severe, sometimes life-threatening pseudo-allergic adverse reaction. In asthmatics, the application of any beta-receptor blocking agents and also the use of parasympathicotonic eye drops for treatment of glaucoma are contraindicated. Paradoxical bronchial constriction following application of antiasthmatics are preponderantly caused by locally irritative actions, less frequently by genuine allergic phenomena or additive intolerance. The most reliable prophylaxis against drug-induced bronchial asthma consists in strong avoidance of all derivatives possibly capable to trigger any intolerance. A respective warning should entered into the emergency passport. 相似文献
155.
H Struck 《Zeitschrift für Gerontologie》1988,21(2):106-109
Today old age represents no contraindication to operative treatment. The age dependence of normal coagulation, immunological system and connective tissue components is described with respect to the course of wound healing. Possible misinterpretations that may occur, if preoperative values do not exist and the subsequent course is not observed, are pointed out. 相似文献
156.
157.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia. 相似文献
158.
159.
B A Thornhill H T Morehouse J C Hoffman-Tretin 《Critical reviews in diagnostic imaging》1988,28(1):1-22
Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed. 相似文献
160.
Milton G. Mutchnick MD Horchang H. Lee MD 《Alcoholism, clinical and experimental research》1988,12(1):155-158
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease. 相似文献