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   232961篇
  免费   15567篇
  国内免费   5904篇
耳鼻咽喉   1782篇
儿科学   3511篇
妇产科学   4397篇
基础医学   37345篇
口腔科学   4375篇
临床医学   16300篇
内科学   30572篇
皮肤病学   3152篇
神经病学   14210篇
特种医学   7377篇
外国民族医学   10篇
外科学   18997篇
综合类   30132篇
现状与发展   30篇
一般理论   8篇
预防医学   19453篇
眼科学   2819篇
药学   29342篇
  59篇
中国医学   13074篇
肿瘤学   17487篇
  2024年   473篇
  2023年   2968篇
  2022年   6509篇
  2021年   8845篇
  2020年   7424篇
  2019年   7226篇
  2018年   7342篇
  2017年   7987篇
  2016年   8007篇
  2015年   7778篇
  2014年   9576篇
  2013年   13735篇
  2012年   11213篇
  2011年   13719篇
  2010年   9087篇
  2009年   9330篇
  2008年   10919篇
  2007年   11882篇
  2006年   11190篇
  2005年   10282篇
  2004年   8885篇
  2003年   8006篇
  2002年   6547篇
  2001年   5900篇
  2000年   5085篇
  1999年   4433篇
  1998年   3647篇
  1997年   3721篇
  1996年   3413篇
  1995年   2994篇
  1994年   2941篇
  1993年   2467篇
  1992年   2287篇
  1991年   2055篇
  1990年   1838篇
  1989年   1473篇
  1988年   1419篇
  1987年   1235篇
  1986年   1120篇
  1985年   1638篇
  1984年   1356篇
  1983年   989篇
  1982年   1019篇
  1981年   842篇
  1980年   791篇
  1979年   638篇
  1978年   420篇
  1977年   343篇
  1976年   324篇
  1975年   220篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
目的:总结Ⅰ期在第2足趾游离移植再造拇(手)指中行趾甲延长的临床应用经验.方法:采用趾甲延长方法对9例(男7,女2例)第2足趾移植再造拇(手)指的患者进行了趾甲延长术,其中拇指8例,食指1例.年龄18~46岁,平均25岁.在再造指距甲根皮缘5 mm处,去除1块矩形皮肤,勿损伤皮下血管网.其高度2 mm,宽度与趾甲相等,将U形皮瓣向近端柔和推剥并缝合.结果:1例术后供区发生表浅感染,经换敷料逐渐愈合.再造的拇(手)指全部成活,可延长趾甲2~3 mm,改善了再造拇(手)指的外形,无指甲生长畸形发生.随访7个月~2年(平均13个月),趾甲外形较好.结论:在第2足趾游离移植再造拇(手)指中应用Ⅰ期趾甲延长术,使趾甲从短小向纵向延长,缩小手指甲与足趾甲之间差异,能改善再造拇(手)指甲外形,且不影响再造指的活动功能,是一种简单有效的手术方法.  相似文献   
92.
We report the case of a 20-year-old man with an ipsilateral mid-third clavicle fracture with grade V acromioclavicular joint (ACJ) dislocation. The combination of these two injuries is rare. A literature search produced various treatment algorithms. In this case, the patient was successfully treated with a Bosworth screw.This work was carried out in the Department of Orthopaedics, William Harvey Hospital, Ashford, Kent, UK  相似文献   
93.
采用~(125)I 标记小鼠抗人IL—2受体(P55)的抗Tac(CD_(25))单克隆抗体,成功地建立了人IL—2受体的免疫放射分析法,动态观察了人外周血淋巴细胞经PHA 刺激24、48和72h 后IL—2受体表达的时间曲线,通过Scatchard 作图分析表明~(125)I—抗Tac 单克隆抗体与PHA 活化的上述三个时间点的T 淋巴细胞的最大结合容量(B_(max))分别为43000位点/细胞、54000位点/细胞和61000位点/细胞。本研究为临床IL—2受体检测提供一种简便的免疫放射测定法。  相似文献   
94.
目的总结地高辛血药质量浓度监测方法,寻求最适的测定方法。方法对近年来国内外与地高辛监测相关的文献进行检索综述分析。结果地高辛血药浓度测定方法很多,常用方法主要有:FPIA、酶免疫分析法、RIA、CLIA、乳胶免疫抑制法、干化学法、HPLC法等。结论通过比较分析其中RIA、CLIA、EIA和HPLC MS 4种方法更好。  相似文献   
95.
Massive immune hemolysis due to passenger lymphocyte-derived anti-D has not been reported in renal transplantation. A 50-year-old (B-positive) male received a dual deceased-donor kidney transplant (B-negative) for diabetic renal failure. Two weeks post-transplant, the patient developed severe hemolytic anemia. The donor anti-D titer was 1:8. The recipient anti-D titer (zero pre-transplant) increased from 1:4 to 1:16 over 4 days. Rapid hemolysis caused severe anemia, minimum Hb = 4.2 g/dL, while selectively lysing the patient's autologous red cells during this time. The hemolytic anemia did not impair the allografts and subsided without monoclonal B-cell pharmacotherapy or apheresis. The anti-D titer decreased to barely detectable levels at four months and had cleared when checked 2 years post-transplant. Transfusion support subsided after two months. If complications of anemia can be avoided, the deleterious effects of hemolysis may be well tolerated by renal allografts using antigen negative transfusion alone.  相似文献   
96.
Background: The Lichtenstein technique for inguinal hernia repair is easy to learn and associated with few complications. However, recent studies have suggested that this technique is inferior to some ‘sutureless’ repair systems in terms of perceived difficulty, operating time, surgeon satisfaction, etc. Methods: We employed a sutureless Lichtenstein technique in 80 consecutive patients with primary unilateral inguinal hernia, to assess patient and trainee surgeon outcomes. Human fibrin glue was used in place of conventional sutures. Results: The mean operating time was 36 min and all patients were discharged 5–6 h after the operation. On a 100-point visual analogue scale, the surgeons rated the difficulty of the operation as low (mean score, 31), and perceived satisfaction as high (mean score, 84). No complications were observed at 12-month follow-up. Conclusion: This study confirms the efficacy of mesh fixation with human fibrin glue, and supports the viability of a sutureless Lichtenstein procedure.  相似文献   
97.
骨髓基质干细胞修复兔关节软骨缺损的实验研究   总被引:1,自引:1,他引:0  
目的研究以多聚乙醇酸(PGA)为支架的骨髓基质干细胞(BMSCs)复合物修复兔膝关节软骨缺损的情况。方法体外培养扩增的自体BMSCs种植于PGA支架并培养72h,然后将支架-细胞复合物植入兔关节软骨缺损模型。术后12周处死动物,标本行大体观察、组织学检查及Ⅱ型胶原免疫组化染色。结果BMSCs-PGA复合物植入后形成丰富的透明软骨样修复组织,新生软骨无明显退变。对照组主要为纤维组织及软骨下骨修复。结论BMSCs-PGA复合物可修复关节软骨缺损。  相似文献   
98.
The effects of cepharanthin on inflammatory parameters such as neutrophil chemotaxis, phagocytosis and reactive oxygen species (ROS) generation, were examined. Cepharanthin significantly decreased the levels of O2-, H2O2, and OH. generated by neutrophils. H2O2 and OH. generated in a cell-free, xanthine-xanthine oxidase system were also reduced in the presence of cepharanthin. However, the drug did not affect neutrophil chemotaxis or phagocytosis. The present study indicates that cepharanthin is an effective ROS scavenger, exerting its anti-inflammatory action by reducing the potent ROS species excessively generated in tissues and organs, especially at the sites of inflammation.  相似文献   
99.
Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences.  相似文献   
100.
Despite the use of gold complexes in modern medicine for over 100 years and the use of gold complexes in the management of rheumatoid disease for more than 60 years, the definitive mechanisms of action for efficacy and for toxicity have not been established. Gold is a group 1b metal in the periodic table with several oxidation states but it is only Au(I) which is active in the biological milieu. Gold sodium thiomalate is not only a polymeric structure, but also has the chiral ligand, thiomalic acid. Gold sodium thiomalate thus can exist in several different physical states which may have different biological activity. In addition the pharmacokinetic profile of gold complexes has been of little value in the understanding of either the mechanism of action, efficacy or toxicity for both the injectable and the oral gold complexes. Many authors have misinterpreted research data on the activities of gold complexes because they compared gold complexes of different structures, and gold complexes which exist at different pH. Experimental work in our laboratory has identified that gold sodium thiomalate is a mixture and can exist as either a yellow or a colourless solution. These have some similar but several different biological activities. Many factors contribute to the lack of understanding of the action of gold complexes. Some of these factors are related to the wide variation in physical structure and biological activities exhibited by these compounds.  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