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   50917篇
  免费   2863篇
  国内免费   497篇
耳鼻咽喉   671篇
儿科学   1836篇
妇产科学   860篇
基础医学   6592篇
口腔科学   1163篇
临床医学   3739篇
内科学   12052篇
皮肤病学   1673篇
神经病学   4098篇
特种医学   1270篇
外国民族医学   2篇
外科学   6325篇
综合类   1303篇
一般理论   16篇
预防医学   4340篇
眼科学   1473篇
药学   3454篇
  6篇
中国医学   530篇
肿瘤学   2874篇
  2024年   60篇
  2023年   399篇
  2022年   583篇
  2021年   1521篇
  2020年   810篇
  2019年   1532篇
  2018年   2191篇
  2017年   1351篇
  2016年   1205篇
  2015年   1218篇
  2014年   1530篇
  2013年   2261篇
  2012年   3809篇
  2011年   4203篇
  2010年   2132篇
  2009年   1396篇
  2008年   3205篇
  2007年   3212篇
  2006年   2929篇
  2005年   3032篇
  2004年   2761篇
  2003年   2642篇
  2002年   2417篇
  2001年   1625篇
  2000年   1986篇
  1999年   1193篇
  1998年   358篇
  1997年   250篇
  1996年   243篇
  1995年   219篇
  1994年   140篇
  1993年   154篇
  1992年   214篇
  1991年   174篇
  1990年   151篇
  1989年   151篇
  1988年   135篇
  1987年   117篇
  1986年   101篇
  1985年   94篇
  1984年   83篇
  1983年   60篇
  1982年   47篇
  1981年   37篇
  1980年   40篇
  1979年   27篇
  1978年   31篇
  1977年   28篇
  1976年   23篇
  1973年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
An inbreeding program has been carried out with the Swiss sublines of Roman high- and low-avoidance rats since 1993. The present study reports the first experiments conducted with young animals of those inbred strains (RHA-I/Verh and RLA-I/Verh, respectively) from the sixth and seventh inbreeding generations. The results confirmed expected behavioral profiles. Compared to the RHA-I/Verh strain, RLA-I/Verh rats showed decreased entries into the illuminated central arena of an hexagonal tunnel maze, as well as decreased spontaneous locomotor activity and increased defecations, in two independent experiments. Young RLA-I/Verh females explored less than did their RHA-I/Verh counterparts during session 1 of a conditioned-fear experiment preceding shock administration, and in session 2 (conducted 24 h after the application of three footshocks), they showed greater conditioned behavioral inhibition (i.e., reduced amount of rearing), as well as higher defecation scores, than did RHA-I/Verh females.Karl Bättig tragically and unexpectedly died on December 27, 1996  相似文献   
113.
Adenosine monophosphate, inosine monophosphate, inosine, adenosine, guanosine, adenine, guanine, hypoxanthine, xanthine and uric acid were determined in cerebrospinal fluid (CSF) of 15 children after complex febrile seizures (CFS) and in 27 after simple febrile seizures (SFS), and compared with those in a control group of 63 children. There was no statistically significant difference between the groups for any of these metabolites, suggesting that CFS and SFS neither significantly disturb the metabolism of nucleotides, nucleosides or bases nor significantly deplete neuron adenosine triphosphate levels.  相似文献   
114.
PURPOSE: To compare two protocols of epidural administration of racemic methadone for postoperative analgesia (continuous infusion and intermittent bolus), focussing on plasma concentration, analgesic efficacy and side effects. METHODS: Ninety patients undergoing abdominal or lower-limb surgery were randomly assigned to two groups in a prospective double-blind design. The continuous infusion patients (n=60) received initial doses of 3 to 6 mg followed by 6 to 12 mg by continuous infusion over 24 hr. The bolus administration patients (n=30) received repeated boluses of 3 to 6 mg of racemic methadone every eight hours. Pain intensity was assessed on a visual analog scale. Amount of supplementary analgesia was recorded, as was the incidence of side effects. Plasma methadone concentrations were determined by high performance liquid chromatography. Treatment was continued for 72 hr. RESULTS: Pain relief was good and comparable in both groups throughout the three days of treatment. No accumulation of plasma racemic methadone was observed in either group, although the concentrations were significantly higher in the bolus group. Miosis was significantly more frequent in the bolus group. CONCLUSION: Plasma methadone concentrations were significantly lower with continuous infusion. Plasma methadone accumulation, which is considered the main disadvantage for its purported influence on the incidence of side effects, did not occur at the doses used over the three days of treatment that we report.  相似文献   
115.
116.
117.
118.
3例前列腺癌施行双侧睾丸节除术后2-12周的患,每天肌注苯甲酸雌二醇1mg,d。治疗前后分别每10min采血一次,作7h LH脉冲分析。结果表明,3例患平均血清LH水平分别由177.58±3.20,138.30±5.83和145.88±3.82IU/LGHBTGC 174.90±7.60,132.02±5.77和142.80±3.65IU/L(P均<0.01),但LH脉冲幅度和频率无明显变化(  相似文献   
119.
120.
We report the sudden development of an inflammatory process thought to be of the floor of the mouth with subsequent involvement of the respiratory airway. MR imaging showed an enhancing posterior lingual lesion, consistent with an abscess. Immediate surgical drainage relieved the symptoms. MR imaging allowed accurate diagnosis, which was essential for surgical planning in a condition that was otherwise difficult to diagnose.  相似文献   
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