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   314882篇
  免费   29910篇
  国内免费   18004篇
耳鼻咽喉   3112篇
儿科学   5154篇
妇产科学   1957篇
基础医学   20811篇
口腔科学   5504篇
临床医学   38132篇
内科学   30722篇
皮肤病学   3764篇
神经病学   7942篇
特种医学   11656篇
外国民族医学   19篇
外科学   29126篇
综合类   81894篇
现状与发展   84篇
一般理论   8篇
预防医学   35306篇
眼科学   4169篇
药学   38594篇
  418篇
中国医学   29220篇
肿瘤学   15204篇
  2024年   2450篇
  2023年   4206篇
  2022年   10097篇
  2021年   12820篇
  2020年   11230篇
  2019年   6625篇
  2018年   6852篇
  2017年   8823篇
  2016年   7267篇
  2015年   12260篇
  2014年   16143篇
  2013年   19552篇
  2012年   27987篇
  2011年   29614篇
  2010年   26111篇
  2009年   23443篇
  2008年   24282篇
  2007年   23296篇
  2006年   20906篇
  2005年   17381篇
  2004年   12055篇
  2003年   10202篇
  2002年   7902篇
  2001年   6996篇
  2000年   5443篇
  1999年   2503篇
  1998年   910篇
  1997年   842篇
  1996年   664篇
  1995年   689篇
  1994年   556篇
  1993年   343篇
  1992年   407篇
  1991年   275篇
  1990年   262篇
  1989年   228篇
  1988年   169篇
  1987年   187篇
  1986年   180篇
  1985年   116篇
  1984年   78篇
  1983年   54篇
  1982年   67篇
  1981年   16篇
  1980年   19篇
  1979年   18篇
  1963年   17篇
  1962年   19篇
  1956年   16篇
  1955年   16篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
2005年4月中旬,应EIZO Nanao Corporation的邀请,我们来到日本对EIZO公司进行了参观访问。以为只是一个例行公务的采访,没想到的是,几天的行程下来,又因为几座美术馆,而让我对EIZO有了新的看法,并且有了意外的收获。  相似文献   
12.
陈名道 《中华内分泌代谢杂志》2006,25(1):增录3b-1-增录3b-2
2008年对糖尿病学界来说是不平凡的一年,2型糖尿病的治疗经历了很多的挑战,也引起了更深入的思考.UKPDS试验后续10年随访、ADVANCE、ACcORD和VADT大型临床研究结果的揭晓,对2型糖尿病预防大血管并发症的治疗理念造成了冲击.  相似文献   
13.
目的:应用间接法制作cerecⅢ全瓷冠,避免了直接法的缺点,使完成的修复体更为精确.方法:从2002年1月至2003年7月采用间接法制备cerecⅢ全瓷冠35个单位,对后牙采用功能法进行设计;对前牙采用数据库法进行设计.戴牙后1个月随访检测颈缘密贴性、牙周状况和与邻牙的邻接状况.结果:后牙采用功能法制备,在模型上调改较少,而前牙采用数据库法制备,在模型上调改较多.戴入患者口内1个月有一后牙病例破损.其它病例全瓷冠颈缘与基牙肩台密贴,与邻牙的邻接状况良好,牙周状况未见异常.结论:对于大多数CerecⅢ的初学者来说,应用间接法可利用较长的时间来反复制取光学印模,光学印模较直接法更准确.还可更为精细地进行修复体的设计并在模型上调改精修修复体.完成修复体后也会有较长时间来总结经验.  相似文献   
14.
A national screening programme for antibody to hepatitis C virus (HCV) in blood donors in Taiwan began in July 1992 using a second-generation immunoassay. To study the impact of this screening on post-transfusion hepatitis in Taiwan, a prospective study on post-transfusion hepatitis, that was started in 1987, was continued. As of June 1994, 245 patients who received a blood transfusion after July 1992 had completed a follow-up period for more than 6 months post-transfusion. Of them, seven (2.8%) recipients developed acute post-transfusion hepatitis. The hepatitis in six cases could not be attributed to infection by hepatitis A, B, C, D, E viruses or cytomegalovirus (CMV) or Epstein-Barr virus (EBV). The remaining patient seroconverted to both IgG and IgM anti-CMV. All seven patients recovered in 6 months without development of chronicity, and the mean peak alanine aminotransferase level was lower compared with that of the cases before anti-HCV screening (i.e. pre-July 1992). These results indicate that the current anti-HCV screening has effectively interrupted HCV transmission through blood transfusion in Taiwan.  相似文献   
15.
16.
In order to understand the mechanism of immunosuppression caused by infusion of placental gamma globulin (PGG) in patients with renal allografts, rheumatoid arthritis, and graft – versus –host disease (GCHD) following bone marrow transplantation (BMT) ,we have examined the effect of PGG in vitro and in a model of the xenogeneic , local graft –ver- sus – host reaction (LGVHR) .PGG inhibited lymphocyte proliferation in mixed lymphocyte cultures (MLC) (P<0.005) and depressed interleukin -2 (IL-2) levels in such cultures at 72 hours (P<0.01) . In contrast phytohemagglutinin (PHA) –and pokeweed mitogen (PWM) –induced T and B lymphocyte blastogenesis was not affected by such PGG treatment .PGG treatment .PGG neither decreased the [3H] TdR pulse incorporation in unstimulated lymphocytes nor affected cell viability .Cell cycle analysis by flow cytometry showed that PGG reduced the percentage of cells in S and G2, M phases during the MLC, but did not alter cell cycling during PWM-stimulated proliferation . An immunosuppressive effect of PGG on the LGCHR was tested in a model of intracutaneous transplantation of PGG –treat human lymphocytes into cyclophosphamide – immunosuppressed rats. Lymphoprep – separated human tonsillar lymphocytes were incubated with RPMI-1640 buffer containing:(1)PGG,4mg/ml,(2) human plasma albumin,4mg/ml,(3)mitomycin-C,25ug/ml, or (4) no additive. Cell of each preparation (3x107cells in 0.1ml) were injected intracutaneously into cyclophosphamide-treated male rats at separate abdominal locations. A fifth site received only the buffer solution. Five days after injection of cells ,each rat received [125 I]IUdR (10uCi) intraperitoneally and was killed after 5 hours. For each site of injection, the diameters of induration were measured and 125 I was counted . There was no difference between buffer – treated and a ibumin – treated groups either in the diameter of the area of induration (t=0.66;P>0.5)or in radioactive counts(t=0.22;P>0.05).In the PGG –treated group, the induration and radioactivity measurements were significantly less than in control groups (t=3.72 and P<0.1;t=2.62 and P<0.02,respectively ) Cytophilic antibodies in PGG were thought to inhibit an early phase of T cell activation, and not to be cytotoxicity .In the LGVHR, the immune response might be abrogated either by immuno- regulatory suppression of T cell function or by toxicity to the infused lymphoid cells. For some clinical purposes, immuno- modulating, human antibodies might be preferred to murine, monoclonal antibodies.  相似文献   
17.
低位无肛术术中完整保留瘘口组织的必要性和可行性   总被引:2,自引:0,他引:2  
目的探讨低位肛门直肠畸形术术中保留瘘口组织的必要性和可行性。方法对67例无肛前庭及会阴瘘患儿的临床资料进行回顾性分析。其中女童无肛前庭瘘59例,男童无肛会阴瘘8例。年龄3个月~16岁,平均10个月。患儿多以排便困难或肛门位置异常就诊。4例无肛前庭瘘患儿曾在婴儿期行瘘口后切术。患儿均采用完整保留瘘口的前矢状入路肛门成形术治疗。结果患儿术后3及6个月常规来院复诊,最长随访8年。65例(97.0%)患儿会阴部矢状切口一期愈合,会阴及肛门外观良好;另2例(男、女各1例)术中直肠破损患儿,自修补处穿孔导致会阴部矢状切口感染(占直肠破损修补术的40%),最终形成直肠会阴瘘,但肛门外观良好。67例均采用肛门功能临床评分标准评估患儿排便功能,64例(95.5%)患儿排便功能良好,总评分为5~6分;另3例(男1例,女2例)顽固便秘,需开塞露协助排便。结论低位无肛术中完整保留瘘口组织非常必要。  相似文献   
18.
朱亮  陈士岭  邢福祺  杜建新  郭宇红 《医学争鸣》2005,26(15):1414-1416
目的:观察环境温度的改变对MⅡ期人卵纺锤体结构的影响.方法:40例非男性因素的不孕妇女,将常规体外授精后未受精的MⅡ期卵子置于室温(23~25℃)直至纺锤体消失.于纺锤体消失后,将卵子分成3个实验组:1组纺锤体消失后立即复温(n=8);2组纺锤体消失后室温下静置5 min再复温(n=6);3组纺锤体消失后室温下静置10 min再复温(n=6).卵子复温后5 min,10 min,2 h分别观察纺锤体的复现情况.结果:20个未受精的MⅡ期卵子置于室温下5 min内纺锤体均消失.1组中的8个卵子,2组中的6个卵子复温后再次观测到了MⅡ期纺锤体.3组中的6个卵子只有3个卵子再次出现了MⅡ期纺锤体.对照组的18个卵子放置于37℃恒温板上观察30 min,纺锤体均未见消失.结论:MⅡ期卵子纺锤体对环境温度的改变非常敏感.温度降低将导致纺锤体消失,随着时间的延长,纺锤体复现几率明显减少.  相似文献   
19.
In-situ forming drug delivery systems are prepared by dissolving a drug and a biodegradable polymer (poly(D,L-lactide-co-glycolide), PLGA) in a biocompatible organic solvent (In-situ implant, ISI) or further emulsified into an external phase (oil or aqueous solution), resulting in oil-in-oil or oil-in-water emulsions (In-situ forming microparticles, ISM). The chemical stability of PLGA and the drug is a major concern. In this study, the stability of PLGA and leuprolide acetate in the in-situ forming systems and lyophilized sponges was investigated. The degradation of PLGA increased with increasing storage temperature and water content in the biocompatible solvents. A faster degradation occurred in polar protic solvents (2-pyrrolidone, PEG 400, triethyl citrate) than in polar aprotic solvents (N-methyl-2-pyrrolidone, DMSO, triacetin, ethyl acetate). The presence of leuprolide acetate significantly accelerated PLGA degradation, especially in solution state. PLGA was stable in oily suspensions at 4 degrees C and degraded only slightly faster than solid powder at 25 degrees C. No interaction between the oils and the PLGA was observed as indicated by an unchanged T(g) of approx. 47 degrees C. PLGA underwent a slight degradation at 4 degrees C after 150 days in water and saturated sodium chloride solution. The degradation was slower in saturated sodium chloride solution than in water at 25 degrees C. Residual acetic acid in lyophilized sponges facilitated the PLGA degradation in contrast to dioxane. Leuprolide acetate did not affect the PLGA stability negatively. However, lidocaine significantly enhanced the polymer degradation in the sponges. Finally, leuprolide acetate was chemically stable in the sponges, the oils and the polymer solutions in suspension state, but unstable (aggregation) when dissolved in the polymer solutions and stored at 25 degrees C and 40 degrees C.  相似文献   
20.
临床护士工作满意度调查及分析   总被引:7,自引:0,他引:7  
目的 探讨护士工作满意度状况及其影响因素.方法 应用Mueller/McCloskey满意度量表(MMSS)对随机抽取的574名护士进行问卷调查,并对结果进行分析.结果 护士对自己工作总体满意程度不高,为(2.95±0.49)分;对工作待遇的满意度最低为(2.10±0.71)分.不同年龄、学历水平护士的工作满意程度比较差异有统计学意义,P<0.05.结论 应根据影响工作满意度因素采取不同的管理措施及激励手段,提高护士的工作满意度.  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