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   88388篇
  免费   9599篇
  国内免费   6667篇
耳鼻咽喉   937篇
儿科学   904篇
妇产科学   765篇
基础医学   9721篇
口腔科学   1641篇
临床医学   11685篇
内科学   12470篇
皮肤病学   1096篇
神经病学   4647篇
特种医学   3328篇
外国民族医学   58篇
外科学   8862篇
综合类   17147篇
现状与发展   29篇
一般理论   6篇
预防医学   6579篇
眼科学   2427篇
药学   9819篇
  78篇
中国医学   5499篇
肿瘤学   6956篇
  2024年   275篇
  2023年   1476篇
  2022年   2835篇
  2021年   4914篇
  2020年   3846篇
  2019年   3131篇
  2018年   3282篇
  2017年   3126篇
  2016年   2845篇
  2015年   4388篇
  2014年   5459篇
  2013年   5017篇
  2012年   7310篇
  2011年   7889篇
  2010年   5060篇
  2009年   4037篇
  2008年   5028篇
  2007年   4748篇
  2006年   4513篇
  2005年   4226篇
  2004年   2794篇
  2003年   2691篇
  2002年   2140篇
  2001年   1784篇
  2000年   1742篇
  1999年   1842篇
  1998年   1113篇
  1997年   1068篇
  1996年   795篇
  1995年   731篇
  1994年   710篇
  1993年   431篇
  1992年   612篇
  1991年   467篇
  1990年   416篇
  1989年   366篇
  1988年   343篇
  1987年   275篇
  1986年   237篇
  1985年   203篇
  1984年   120篇
  1983年   63篇
  1982年   46篇
  1981年   47篇
  1980年   20篇
  1979年   45篇
  1978年   16篇
  1977年   14篇
  1975年   8篇
  1936年   8篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
91.
昆虫色氨酸羟化酶的研究进展   总被引:5,自引:0,他引:5  
色氨酸羟化酶(tryptophan hydroxylase、TPH)为5-羟色胺(5-hydroxytryptamine,5-HT)合成的限速酶,具有专一性,在组织中含量较低,且具有不稳定性。TPH的活性是5-HT合成的唯一前提,因此它可以作为5-HT能神经元的特异标志,也可以作为5-HT能神经元的一个分化特征。它的存在,住区分神经细胞特征方面比5-HT本身的含苗更有价值。因而近年来TPH迅速成为国际研究的热点和难点之一。本文主要就TPH在昆虫中的存在形式、调节机制及进化地位等方面已取得的研究进展作一简述。  相似文献   
92.
Single or combined monoclonal antibodies (McAbs) Zh53, Zh820, and Zh2-1 have been used to eliminate malignant clonogenic cells from human bone marrow. The test of cytotoxicity showed that all of these McAbs could express high specific cytotoxic action against HL-60 cells and were selectively complement-dependent cytotoxic to various types of fresh leukemic cells. Clonogenic assay detected that single treatment with antibody and rabbit complement (RC) could reduce clonogenic units of HL-60 cells by more than 2 logs and two treatments reduced clonogenic units by more than 4 logs. However, combination of 2 McAbs could reduce clonogenic units by 4-5 logs. The data suggest that multiple treatments with McAbs and RC or a combination of 2 McAbs are more effective than a single treatment in eliminating clonogenic tumor cells. Treatment of normal human bone marrow with Zh53, Zh2-1 and RC did not produce a loss of normal CFU-GM, but treatment with Zh820 reduced the clonic units of normal CFU-GM by 24%.
  相似文献   
93.
The toxic effects of nitroquine-dapsone compound(NQD)in mice and dogs were studied.The therapeutic index of NQDin mice is 1911,the greatest among the 6 antimalarials tested.Thetoxic effects of NQD(50 mg/kg/day for 3 days per os)and nitro-quine in dogs were manifested by injuries on the adrenal cortexand intestinal epithelium.When folic acid(4 mg/kg/day for 4 days)or calcium leucovorinum(0.3 mg/kg/day for 4 days)were usedconcomitantly with NQD,the death rate and the incidence of dia-rrhea in the toxicated dogs were greatly reduced,the injury on theintestinal epithelium was much milder,and the goblet cells weremuch more numerous than those without treatment.The results suggestthat folic acid and calcium leucovorinum can protect the undifferen-tiated cells in the intestinal crypts from being injured by NQD.  相似文献   
94.
文章从医院人性化管理的定义,僵硬制度化管理的弊端,医院人性化管理的作用,怎样人性化管理职工和患者,阐明了如何实现医院人性化管理的问题。  相似文献   
95.
3种雾化吸入法治疗支气管哮喘的比较   总被引:1,自引:0,他引:1  
李秀英  梁玉娟  胡玉莲 《护理研究》2005,19(27):2466-2467
近年来,随着环境的污染及病毒感染的蔓延,支气管哮喘将是21世纪影响人类健康的大敌.为探求治疗支气管哮喘的新疗法,比较3种雾化吸入法对支气管哮喘的治疗效果,寻找一种最安全、最有效、最可靠的治疗方法.……  相似文献   
96.
Neurotropin (NSP) is an extract isolated from the skin of rabbits inoculated with vaccinia virus. The present study examines the possible action of NSP on the number and function of immunocompe tent cells in mice. The experiment showed that NSP had no effect on both T and B lymphocytes of nor- malimmunized mouse spleen. The degree of plaque forming cell reaction and titre of specific antibody showed no significant differences when the NSP treated group and controls were compared. How- ever, NSP exhibited promotive effect on specific antigen binding cells in the early stage of immune responses. It was also noted that the rosette forming capacity of human T lymphocytes in vitro was restor- ed markedly by NSP. These results suggest that NSP possesses certain immunostimulating activity, particularly on the specific antigen binding cells and human T lymphocytes.  相似文献   
97.
PURPOSE: To evaluate a computational approach that incorporates experimental data in preclinical models to depict doxorubicin human tissue pharmacokinetics. EXPERIMENTAL DESIGN: Beagle dogs were given 2 mg/kg doxorubicin as i.v. bolus, 4-h infusion, or 96-h infusion. Concentrations in plasma, prostate (target tissue), heart (toxicity), and major tissues for disposition were determined and modeled. Model parameters were obtained after the bolus injection with model validation based on the 4-h and 96-h infusion data. Clinical pharmacokinetic data and scale-up gave doxorubicin profiles in human prostate and heart. RESULTS: In agreement with in vitro results, tissues were best modeled with two compartments, one rapidly and one slowly equilibrating. The developed tissue distribution model predicted concentrations for all three administration regimens well, with an average deviation of 34% (median, 29%). Interspecies scale-up to humans showed that the change from a bolus injection to a slow, 96-h infusion (a) had different effects on the drug partition and accumulation in heart and prostate, and (b) lowered the peak concentration in the plasma by approximately 100-fold but had relatively little effect on maximal heart concentration ( approximately 33% lower). The simulated drug exposure in a human prostate was above the exposure required to inhibit tumor proliferation but was 30 to 50 times below that needed for cell death. CONCLUSION: The present study shows a computation-based paradigm for translating in vitro and in vivo preclinical data and to estimate and compare the drug delivery and pharmacokinetics in target tissues after different treatment schedules.  相似文献   
98.
[目的]探讨儿童频繁瞬目征的发病原因及其治疗措施。[方法]随机抽取148例门诊频繁瞬目征患儿,对其生活习惯、眼部情况进行详细询问并进行病因分析及综合治疗。[结果]通过克服不良生活习惯、去除谤因、调节心理和综合治疗措施,148例频繁瞬目征惠患儿经2周~5周的治疗,115例患儿治愈,28例好转,5例无效。[结论]频繁瞬目征与玩电脑、看电视及偏食有一定关系,针对性综合治疗可获得较满意的疗效。  相似文献   
99.
三维立体培养法诱导去分化软骨细胞Ⅱ型胶原的重新表达   总被引:2,自引:0,他引:2  
目的用藻酸盐三维立体培养法及离心管聚集体诱导培养法促进去分化的永生化软骨细胞第50代(IHACs50)重新表达软骨细胞的Ⅱ型胶原标志性表型。方法利用藻酸盐三维立体培养法以及离心管聚集体诱导培养法分别诱导培养去分化的永生化人关节软骨细胞第50代,然后用Ⅰ、Ⅱ、Ⅲ型胶原的免疫组织化学染色、Ⅱ型胶原的逆转录-聚合酶链反应(RT-PCR)检测、激光共聚焦显微镜检测、胶原定量检测该永生化软骨细胞的Ⅱ型胶原表型表达情况。结果免疫组织化学染色、激光共聚焦显微镜检测、RT-PCR检测分别提示藻酸盐三维立体培养法和离心管聚集体诱导培养法使去分化永生化人关节软骨细胞的Ⅱ型胶原染色阳性以及621 bp的Ⅱ型胶原mR- NA表达,Western blot和3H-脯氨酸标记SDS-PAGEⅡ型胶原定量检测发现前者促进Ⅱ型胶原分泌较后者多。结论去分化永生化人关节软骨细胞可以经不同的诱导方法而重新表达Ⅱ型胶原表型,藻酸盐三维立体培养法因与软骨细胞的生理环境相似,故促进Ⅱ型胶原重新表达较多。  相似文献   
100.
[目的]分析讨论桡骨小头假体置换治疗MasonⅢ型骨折的临床疗效。[方法]采用双极桡骨小头假体对7例成人MasonⅢ型骨折患者进行了手术治疗。[结果]随访6-11个月,按照Morrey和Broberg的肘部功能评分标准进行评定,总的优良率达83%。[结论]桡骨小头假体置换对成人MasonⅢ型骨折的治疗非常适合。  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