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   2134篇
  免费   129篇
  国内免费   12篇
耳鼻咽喉   14篇
儿科学   92篇
妇产科学   47篇
基础医学   269篇
口腔科学   51篇
临床医学   142篇
内科学   385篇
皮肤病学   15篇
神经病学   147篇
特种医学   72篇
外科学   258篇
综合类   65篇
预防医学   141篇
眼科学   152篇
药学   289篇
中国医学   50篇
肿瘤学   86篇
  2023年   15篇
  2022年   30篇
  2021年   79篇
  2020年   38篇
  2019年   57篇
  2018年   66篇
  2017年   43篇
  2016年   66篇
  2015年   62篇
  2014年   98篇
  2013年   98篇
  2012年   149篇
  2011年   157篇
  2010年   88篇
  2009年   64篇
  2008年   109篇
  2007年   92篇
  2006年   90篇
  2005年   77篇
  2004年   86篇
  2003年   90篇
  2002年   76篇
  2001年   34篇
  2000年   38篇
  1999年   25篇
  1998年   16篇
  1997年   18篇
  1996年   12篇
  1995年   8篇
  1993年   9篇
  1992年   39篇
  1991年   37篇
  1990年   25篇
  1989年   35篇
  1988年   23篇
  1987年   18篇
  1986年   15篇
  1985年   12篇
  1984年   28篇
  1983年   14篇
  1980年   11篇
  1979年   17篇
  1978年   8篇
  1976年   10篇
  1975年   9篇
  1974年   12篇
  1973年   13篇
  1972年   12篇
  1971年   9篇
  1969年   9篇
排序方式: 共有2275条查询结果,搜索用时 93 毫秒
1.
2.
3.
A sublethal concentration of technical grade endosulfan (END) inhibited 35 to 55% of the activities of cytoplasmic malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH), and lactate dehydrogenase (LDH) in the liver and the skeletal muscle of a freshwater catfish, Clarias batrachus, after 7 days of exposure. The activity remained in the inhibited state up to 28 days. The withdrawal of END from the medium after 1 week of exposure gradually restored the activities to control levels within 21 days in the skeletal muscle and 28 days in the liver. The administration of actinomycin D or cycloheximide between the 14th and the 21st day of the withdrawal of END almost completely inhibited the withdrawal-dependent recovery in the activities of all the three enzymes. This indicates de novo synthesis of the enzymes during the recovery period. A conjoint treatment of END and triiodothyronine (T3) raised the activities of cMDH, mMDH, and LDH in the liver and the skeletal muscle up to the control levels. This shows that the inhibitory effect of END may be relieved in presence of T3. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed few changes in the pattern of cytoplasmic proteins of the liver and the skeletal muscle in response to exposure to END.  相似文献   
4.
慢性胰腺炎的临床表现包括疼痛、脂肪泻和糖尿病。在西方国家,慢性胰腺炎最常见的病因是酗酒。70%以上的病人在就诊时有疼痛的临床表现,而且,这些患者中又有75%以上会在几年之后出现疼痛减轻或完全消失。对于所有的慢性胰腺炎的病人来说,均应排除非胰源性疼痛和胆道梗阻、胰腺假性囊肿等胰腺局部并发症。应建议所有慢性胰腺炎病人戒烟、戒酒。阿片类镇痛剂仅应用于治疗疼痛严重的病人。尽管有报道认为胰酶替代治疗有助于止痛,但是,对于已经确诊的慢性胰腺炎病人来说,该疗法无效。激素类药物进行腹腔神经丛阻滞术可能有助于病人度过剧烈疼痛期。顽固性疼痛是进行胰液引流或胰腺切除的适应证。建议应用适量胰酶替代联合(或不联合)制酸剂治疗营养不良。慢性胰腺炎导致的糖尿病与原发性糖尿病的治疗原则相似。  相似文献   
5.
Ten smoker sportsmen and 17 non-smoker sportsmen and 41 smoker non-sportsmen were studied. Lung function was assessed by means of Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), the ratio of FEV1 to FVC (FEV1%) and Peak Expiratory Flow Rate (PEFR). For the smokers, all the tests were conducted before smoking (BS) and 30 min after smoking (AS) two cigarettes consecutively to observe the acute effect of smoking. In the smoker sportsmen there was no significant difference between BS and AS measures of lung function. Before smoking smoker sportsmen had lower values for FEV1, FEV1% and PEFR than non-smoker sportsmen (p less than 0.05). However, smoker sportsmen show higher BS values of FEV1 (p less than 0.01), FEV1% (p less than 0.01) and PEFR (p less than 0.05) compared with those of smoker non-sportsmen who had similar smoking indices. These results indicated that the smoker sportsmen, despite exhibiting some degree of lung function impairment in relation to non-smoker sportsmen, still maintained rather better lung function status than the smoker non-sportsmen.  相似文献   
6.
Mice were fed for 24 weeks with three different subtoxic dosages of γ-HCH (0.012, 0.12 and 1.2 mg/kg) mixed in powdered feed. The immunological profile was assessed at an interval of one month during the entire exposure period. Both the cell mediated and humoral components of immunity showed a biphasic response characterized initially by stimulation followed by suppression in a dose dependent manner. However, γ-HCH did not affect the functional properties of peritoneal macrophages. Histological changes in lymphoid organs were in accordance with the biphasic immunomodulatory effects of γ -HCH.  相似文献   
7.
A case of veruccous carcinoma of the maxilla extending to alveulus and palate is reported. Treated with radical maxillectomy: there has been no recurrence within one year. The coexistance of submicous fibrosis and veruccous carcinoma is observed and the histological features of the later are highlighted.  相似文献   
8.
9.

Background and Purpose:  

Higher rates of glucose utilization and glycolysis generally correlate with poor prognosis in several types of malignant tumors. Own earlier studies on model systems demonstrated that the nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DG) could enhance the efficacy of radiotherapy in a dose-dependent manner by selectively sensitizing cancer cells while protecting normal cells. Phase I/II clinical trials indicated that the combination of 2-DG, at an oral dose of 200 mg/kg body weight (BW), with large fractions of γ-radiation was well tolerated in cerebral glioma patients. Since higher 2-DG doses are expected to improve the therapeutic gain, present studies were undertaken to examine the tolerance and safety of escalating 2-DG dose during combined treatment (2-DG + radiotherapy) in glioblastoma multiforme patients.  相似文献   
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