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   23762篇
  免费   1195篇
  国内免费   85篇
耳鼻咽喉   175篇
儿科学   353篇
妇产科学   385篇
基础医学   2935篇
口腔科学   755篇
临床医学   1715篇
内科学   5727篇
皮肤病学   416篇
神经病学   2126篇
特种医学   1076篇
外科学   3683篇
综合类   89篇
预防医学   684篇
眼科学   408篇
药学   1840篇
中国医学   57篇
肿瘤学   2618篇
  2023年   124篇
  2022年   231篇
  2021年   422篇
  2020年   228篇
  2019年   332篇
  2018年   393篇
  2017年   298篇
  2016年   394篇
  2015年   410篇
  2014年   554篇
  2013年   643篇
  2012年   1019篇
  2011年   1187篇
  2010年   592篇
  2009年   556篇
  2008年   1016篇
  2007年   1024篇
  2006年   992篇
  2005年   1011篇
  2004年   979篇
  2003年   958篇
  2002年   1015篇
  2001年   918篇
  2000年   940篇
  1999年   923篇
  1998年   306篇
  1997年   244篇
  1996年   227篇
  1995年   190篇
  1994年   166篇
  1993年   155篇
  1992年   658篇
  1991年   572篇
  1990年   600篇
  1989年   580篇
  1988年   493篇
  1987年   456篇
  1986年   452篇
  1985年   405篇
  1984年   281篇
  1983年   236篇
  1980年   93篇
  1979年   240篇
  1978年   144篇
  1977年   128篇
  1975年   100篇
  1974年   95篇
  1972年   105篇
  1971年   103篇
  1969年   101篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
This retrospective study aimed to evaluate radiation-induced pneumonitis (RIP) and a related condition that we define in this report—prolonged minimal RIP (pmRIP)—after stereotactic body radiotherapy (SBRT) for Stage I primary lung cancer in patients with chronic obstructive pulmonary disease (COPD). We assessed 136 Stage I lung cancer patients with COPD who underwent SBRT. Airflow limitation on spirometry was classified into four Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, with minor modifications: GOLD 1 (mild), GOLD 2 (moderate), GOLD 3 (severe) and GOLD 4 (very severe). On this basis, we defined two subgroups: COPD-free (COPD −) and COPD-positive (COPD +). There was no significant difference in overall survival or cause-specific–survival between these groups. Of the 136 patients, 44 (32%) had pmRIP. Multivariate analysis showed that COPD and the Brinkman index were statistically significant risk factors for the development of pmRIP. COPD and the Brinkman index were predictive factors for pmRIP, although our findings also indicate that SBRT can be tolerated in early lung cancer patients with COPD.  相似文献   
2.
3.
4.
Experiments were performed on spinalized rats, transected at the Cl level. The intravenous administration of TRH and its analog YM-14673 (N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate) produced marked increases in the amplitude of mono- and polysynaptic reflex potentials and those of the withdrawal flexor reflexes. The effects of YM-14673 were stronger and longer-lasting than those of TRH. The stimulant action of TRH and YM-14673 on the flexor reflexes was not antagonized by prazosin, chlorpromazine, haloperidol or cyproheptadine, suggesting no involvement of the release of catecholamines or serotonin in the stimulant effects of TRH and its analog. Therefore, YM-14673 may be beneficial for the treatment of several spinal motor neuron diseases.  相似文献   
5.
S Yamada 《Journal of UOEH》1988,10(2):211-218
Physical activity and nutrition are the most important factors in preserving and/or improving health conditions. The relationship between exercise and nutrition is focused on two different directions: one is the direction toward health promoting, the other is for performance of a long heavy muscular work. For preserving and/or promoting health conditions, energy balance between intake and expenditure must be taken into account. The amount of glycogen stored in muscles is the essential factor to promote a long distance performance of working muscles. Topics that influence the energy balance and glycogen loading used by endurance athletes to improve performance are reviewed.  相似文献   
6.
In the focal infarction model of the rat middle cerebral artery (MCA), the thalamus of the occluded side becomes gradually atrophic, mainly because of retrograde degeneration. We determined whether basic fibroblast growth factor (bFGF) administered intracisternally could prevent this thalamic atrophy. We occluded the left MCA through a small cranial opening, and animals were then divided into two groups. One group received intracisternal injections of recombinant bFGF (1 microgram dissolved in 0.1 ml of saline with 2% rat serum) starting 1 day after occlusion and repeated once a week to a total dose of 4 micrograms by four injections. The other group received vehicle solution by the same schedule. The animals were perfused and fixed at 28 days after occlusion, and histological examination was made at the level of the caudoputamen and thalamus. In the bFGF-treated rats, the area of the posterior ventral thalamus of the occluded side was 93% of that of the contralateral side, i.e., significantly larger than in the normal saline-treated rats (75%, p less than 0.01). The infarction size was not statistically different in the two groups. Microscopic observation indicated that normal-saline-treated animals showed shrinkage and disappearance of thalamic neurons, whereas bFGF-treated groups showed preservation of thalamic neurons. Computerized analysis of the cell size substantiated this observation. To assess the effect of bFGF on astrocytes, bFGF or vehicle solution was injected into normal rats, and their histology was evaluated at 1, 2, and 4 weeks after injection. The bFGF-injected group showed a significant increase in glial fibrillary acidic protein-positive astrocytes in the brain tissue facing the ventriculocisternal system.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
7.
8.
9.
10.
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