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   140030篇
  免费   13236篇
  国内免费   9143篇
耳鼻咽喉   1409篇
儿科学   1559篇
妇产科学   1361篇
基础医学   16903篇
口腔科学   2562篇
临床医学   16914篇
内科学   21046篇
皮肤病学   1993篇
神经病学   7345篇
特种医学   6068篇
外国民族医学   68篇
外科学   14182篇
综合类   22862篇
现状与发展   45篇
一般理论   12篇
预防医学   9613篇
眼科学   4160篇
药学   15225篇
  105篇
中国医学   7287篇
肿瘤学   11690篇
  2024年   448篇
  2023年   2070篇
  2022年   5073篇
  2021年   6709篇
  2020年   4944篇
  2019年   4401篇
  2018年   4598篇
  2017年   4318篇
  2016年   4353篇
  2015年   6529篇
  2014年   8093篇
  2013年   7561篇
  2012年   11339篇
  2011年   12111篇
  2010年   7656篇
  2009年   6309篇
  2008年   8194篇
  2007年   7788篇
  2006年   7513篇
  2005年   6955篇
  2004年   4937篇
  2003年   4870篇
  2002年   4049篇
  2001年   3043篇
  2000年   2800篇
  1999年   2845篇
  1998年   1753篇
  1997年   1642篇
  1996年   1279篇
  1995年   1174篇
  1994年   1147篇
  1993年   731篇
  1992年   928篇
  1991年   757篇
  1990年   666篇
  1989年   579篇
  1988年   483篇
  1987年   440篇
  1986年   352篇
  1985年   270篇
  1984年   153篇
  1983年   97篇
  1982年   82篇
  1981年   67篇
  1980年   46篇
  1979年   58篇
  1978年   21篇
  1977年   16篇
  1975年   14篇
  1973年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的评价烤瓷贴面的修复效果。方法选择20例患者制作烤瓷贴面92个。复诊时对烤瓷贴面的边缘适合性,边缘着色及颜色进行评价;同时采用牙龈出血指数和菌斑指数评价治疗前后的牙周状况。观察时间为12~18个月。结果5颗牙烤瓷贴面失败,成功率为95.7%;烤瓷贴面治疗前后牙龈出血指数无显著性差异(P>0.05),治疗后菌斑指数降低(P<0.01)。结论烤瓷贴面具有较好的治疗效果。  相似文献   
62.
T C Liou  X Z Lin  T T Chang  C Y Lin  P W Lin  Y T Jin  C Y Yu 《Pancreas》1992,7(2):251-256
A 61-year-old man experienced four bouts of pancreatitis in 1 year. Detailed history taking and a series of examinations, including sonography, computed tomography scan, and endoscopic retrograde cholangiopancreatography (ERCP), revealed pancreas divisum on the first admission. He was treated conservatively. However, repeated ERCP on the fourth admission, 1 year later, showed a small filling defect in the tail of the pancreatic duct. A distal pancreatectomy was carried out. Pathological studies revealed a small papillary adenocarcinoma (1.5 x 1.0 x 0.5 cm) confined to the pancreatic duct grossly with minimal parenchymal invasion microscopically. He has been free from cancer and pancreatitis for 13 months since the operation.  相似文献   
63.
A new hemoglobin variant with a Ser----Phe substitution at position beta 49(CD8) was discovered in two members of a family living in the Canary Islands, Spain. Detection was by polyacrylamide gel electrophoresis and by reversed phase high performance liquid chromatography. The variant, which constituted 43% and 45%, respectively, in the two heterozygotes, was slightly unstable. Its presence did not affect hematological values though there was a mild reticulocytosis.  相似文献   
64.
取32只2~3个月的BALB/C小白鼠,随机分为4组,每组8只,第1组为对照组,其余3个组为实验组,实验组小白鼠左腿皮下注射苯0.3ml(15ml/kg体重).注射后分别于24h,48h,72h脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明,苯中毒时骨髓变化先于末梢血象的变化,骨髓的病变为造血细胞变性、坏死,大量毛细血管扩张、充血,骨髓细胞构成降低,而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。  相似文献   
65.
15例离退休健康男性老人和9例红细胞增多症男性病人返回平原后,记忆功能改变的特点:①两组受试者除5例成绩下降外,苏州记忆成绩高于西宁成绩(p<0.01)。②记忆成绩降低现象存在于20%左右的人中。③高原缺氧和返平原脱适应均主要影响短时记忆。  相似文献   
66.
Thrombocytopenia is a frequent finding following living donor hepatectomy. It appears more pronounced in right graft donors than in left graft donors. This study analyzed postoperative thrombocytopenia in 20 living liver donors and examined the change of endogenous thrombopoietin (TPO) in its recovery. Platelet count, TPO level, fibrinogen degradation product (FDP), and D-Dimer were measured before surgery and on postoperative days (PODs) 1, 2, 3, 5, 7, and 14. Concurrently, liver and spleen volumes were calculated by computed tomography. Platelet count on POD 3 was significantly lower in right graft donors than in left graft donors (13.0 +/- 3.7 x 10(4)/microL vs. 16.8 +/- 4.0 x 10(4)/microL, P = 0.039) but recovered by POD 7 in all donors. Postoperative elevations of FDP and D-Dimer were significantly higher in right graft donors than in left graft donors. TPO level rose immediately after surgery, peaked on POD 5 in left graft donors and on POD 7 in right graft donors, and fell nearly to preoperative levels by POD 14. Postoperative TPO level per liver volume was significantly higher in right graft donors than in left graft donors. In conclusion, thrombocytopenia following living donor hepatectomy resolved within the first week regardless of graft type and was mainly associated with increasing consumption of circulating platelets, possibly due to intrahepatic and splenic congestion. With a reduced number of circulating platelets, TPO level rapidly increases. Also, with reduced consumption of platelets related to recovery from surgery, thrombocytopenia should resolve. As a consequence, TPO level would be expected to fall.  相似文献   
67.
目的避免或减少老年人植入心脏起搏器术后疗养康复过程中起搏器故障和相关疾病的发生。积极治疗基础疾病,改变其不良症状,并通过心理治疗改善不良心理情绪,使其增强自信,提高生活质量。方法入院后,详细了解安置起搏器的时间、类型及工作情况,全面掌握其身体状况和心理特点,为其制定合理的疗养计划。结果疗养期结束后,疗养员无一例出现起搏器故障和发生相关疾病;基础疾病及不良症状得到进一步控制,心理不良情绪得到进一步控制,基本达到了疗养的目的。结论疗养院医务人员应全面了解起搏器的类型及特性;掌握安置起搏器的适应症和容易出现的病症;掌握此类疗养员的身体情况和心理特点,制定合理的疗养计划并按计划认真予以实施,是保证老年人植入心脏起搏器疗养员能够顺利完成疗养生活的有效措施。  相似文献   
68.
R Hu  C Beck  Y B Chang  L J DeGroot 《Autoimmunity》1992,12(2):103-106
Inheritance of Graves' disease has been linked to the HA-DR3 gene product which may function in some specific way in antigen presentation. To determine whether the first extracellular domain of this protein, which is specifically involved in antigen presentation, has the same sequence in patients with Graves' disease and in normal individuals, we have amplified the second exon using the polymerase chain reaction, and then cloned and sequenced the DNA segment. In eight subjects with Graves' disease, sequences identical to prototypic reported sequence for DRB1*0301 were recovered, and in two individuals sequences varied by a few nucleotides, leading to 1-3 amino acid substitutions which did not occur in a pattern. Sequences identical to the prototypic sequence known as DRB3*0101, also previously known as DRw52, were also recovered. Thus the HLA-DRB1 and B3 genes present in patients with autoimmune disease appear to be the same as those present in the general population. These observations indicate that a unique allele is not present in patients with autoimmune disease, but rather that the normal DR3 allele itself, in a manner yet to be described, increases the probability of developing autoimmune thyroid disease.  相似文献   
69.
目的:探讨奎的平、氯氮平对精神分裂症的疗效及副作用。方法:80例患者随机分为两组,分别应用奎的平或氯氮平治疗6周,采用四级临床疗效评定标准、阳性症状与阴性症状量表(PANSS)、副反应量表(TESS)评定疗效及副反应。结果:奎的平组有效率87.5%,氯氮平组有效率82.5%。治疗第一周末,奎的平组PANSS量表总分较治疗前差异有显著性(P<0.05)。奎的平组副反应低于氯氮平组。结论:奎的平与氯氮平疗效相似,但奎的平起效较快,副反应较轻。  相似文献   
70.
本文报告了经手术病理证实的53例甲状腺肿瘤,均作了甲状腺造影和B超检查.通过比较分析,我们认为造影对确定肿瘤的良、恶性以及延伸到胸骨后的异位甲状腺肿瘤有其优越性,是一项有效的检查方法;超声则能准确地判断肿瘤的囊、实性,适合碘过敏患者的检查.两种检查各有特点,配合使用有利于对甲状腺肿瘤的诊断和治疗.  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