全文获取类型
收费全文 | 8239篇 |
免费 | 499篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 113篇 |
儿科学 | 248篇 |
妇产科学 | 198篇 |
基础医学 | 1099篇 |
口腔科学 | 139篇 |
临床医学 | 908篇 |
内科学 | 1549篇 |
皮肤病学 | 96篇 |
神经病学 | 644篇 |
特种医学 | 552篇 |
外科学 | 1438篇 |
综合类 | 131篇 |
一般理论 | 1篇 |
预防医学 | 579篇 |
眼科学 | 141篇 |
药学 | 504篇 |
中国医学 | 12篇 |
肿瘤学 | 442篇 |
出版年
2023年 | 34篇 |
2022年 | 36篇 |
2021年 | 110篇 |
2020年 | 60篇 |
2019年 | 109篇 |
2018年 | 165篇 |
2017年 | 117篇 |
2016年 | 111篇 |
2015年 | 145篇 |
2014年 | 232篇 |
2013年 | 336篇 |
2012年 | 446篇 |
2011年 | 429篇 |
2010年 | 300篇 |
2009年 | 245篇 |
2008年 | 439篇 |
2007年 | 562篇 |
2006年 | 454篇 |
2005年 | 529篇 |
2004年 | 440篇 |
2003年 | 452篇 |
2002年 | 400篇 |
2001年 | 111篇 |
2000年 | 96篇 |
1999年 | 96篇 |
1998年 | 127篇 |
1997年 | 104篇 |
1996年 | 139篇 |
1995年 | 108篇 |
1994年 | 104篇 |
1993年 | 97篇 |
1992年 | 99篇 |
1991年 | 102篇 |
1990年 | 85篇 |
1989年 | 86篇 |
1988年 | 103篇 |
1987年 | 88篇 |
1986年 | 88篇 |
1985年 | 99篇 |
1984年 | 83篇 |
1983年 | 70篇 |
1982年 | 80篇 |
1981年 | 78篇 |
1980年 | 53篇 |
1979年 | 54篇 |
1978年 | 48篇 |
1977年 | 54篇 |
1976年 | 54篇 |
1975年 | 43篇 |
1974年 | 30篇 |
排序方式: 共有8794条查询结果,搜索用时 15 毫秒
21.
22.
23.
Brain-tumor cell kinetics correlated with survival 总被引:1,自引:0,他引:1
J W Bookwalter R G Selker L Schiffer M Randall D Iannuzzi M Kristofik 《Journal of neurosurgery》1986,65(6):795-798
In a review of 38 glioblastoma patients for whom fresh tissue kinetic data were available before any therapy was instituted, no correlation between the labeling index and survival time could be statistically determined. This relationship seems entirely consistent with the published theoretical determinants of tumor behavior: that is, altered ability for growth arrest and differentiation, constantly evolving mutant sublines, genetic instability, and an ever-changing metabolic and vascular environment. 相似文献
24.
Carrie L. Randall PhD Raymond F. Anton MD Howard C. Becker PhD 《Alcoholism, clinical and experimental research》1988,12(3):412-416
The purpose of this study was to determine the role of alcohol-induced maternal hypothermia in the teratogenic actions of alcohol. C57BL/6J mice were administered an acute dose of alcohol (5.8 g/kg orally) or isocaloric sucrose on day 10 of gestation. One half of each group was placed for 6 hr in an incubator set at 32 degrees C and the other half was housed in the incubator at room temperature (22 degrees C). As expected, acute prenatal alcohol exposure at this time of gestation was associated with decreased birth weight and an increase in limb and kidney malformations. The significant alcohol x environmental temperature interaction on these dependent variables indicated that the teratogenic insult was not attenuated, but was in fact even greater for the 32 degrees C/alcohol group. An absence of a main effect of environmental temperature indicated that the 32 degrees C environment, per se, was not teratogenic. Thus, maternal hypothermia is probably not an etiological factor in animal models of fetal alcohol syndrome. Moreover, antagonism of alcohol-induced maternal hypothermia exacerbates the teratogenic actions of alcohol observed at room temperature. 相似文献
25.
26.
Esinduy Canan B.; Chang Chia Cheng; Trosko James E.; Ruch Randall J. 《Carcinogenesis》1995,16(4):915-921
We examined whether the inhibition of neoplastically transformedcell growth by co-cultured non-transformed cells involved gapjunctional intercellular communication (GJIC). The growth ofpoorly communicating ( 相似文献
27.
28.
L Hoffman-Goetz B MacNeil Y Arumugam J Randall Simpson 《International journal of sports medicine》1992,13(2):167-171
Acute exercise and exercise conditioning have been shown to affect the activity of natural killer (NK) cells as well as the growth of experimentally induced tumors in animals. Since psychosocial factors are also known to alter NK activity and tumor growth, isolation, a known psychosocial stressor of mice, was also investigated to see if housing condition could alter exercise-induced changes in NK cell activity and tumor growth. NK cell activity and concentration of asialo GM1 (ASGM1) positive splenocytes were measured in male C3H mice inoculated i.v. with CIRAS 3 tumor cells. Mice were housed individually or in groups of four and trained to run for eight weeks on a rodent treadmill; controls remained sedentary throughout the experimental period. At four weeks into the training protocol, mice were injected with the tumor cells and continued to run for four weeks after tumor exposure. There was a significant effect of physical activity (p less than 0.019) but not of housing on splenic NK cytotoxicity against tumor targets in vitro. When the data were analyzed by presence or absence of lung metastases, only those animals without visible lung tumors had significantly higher NK activity as a function of exercise relative to sedentary controls. There were no significant differences in the frequency of ASGM1+ splenocytes between trained and untrained animals, irrespective of presence or absence of lung tumor colonies. There was a significant effect of housing (p less than 0.02), but not of physical activity, in mice with successful tumor takes with greater numbers of group housed animals (29/59) with tumor relative to individually housed animals (13/60).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
29.
Beverly M. Genez M.D. Victor L. Zirilli M.D. Alan E. Schlesinger M.D. Elizabeth A. Harden M.D. Kim D. Murphy M.D. Randall F. Dryer M.D. 《Skeletal radiology》1988,17(4):306-309
The opinions or assertions contained herein are the private views of the authors and are not to be construed as official nor as reflecting the views of the United States Air Force 相似文献
30.
Most clinicians agree that psychological factors are important considerations in the evaluation and treatment of headache patients. There has been a lack of systematic research, however, that has examined the relationship between these variables. Attention to such factors may become a greater concern as the frequency of a patient's headaches increases, there is increased disability secondary to headaches, and/or there is an inadequate response to usually effective treatment. In addition, there is no consensus as to the proper method to assess psychopathology in headache patients. 相似文献