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   146460篇
  免费   12788篇
  国内免费   8732篇
耳鼻咽喉   1499篇
儿科学   2168篇
妇产科学   1162篇
基础医学   14275篇
口腔科学   2571篇
临床医学   16514篇
内科学   20700篇
皮肤病学   1846篇
神经病学   6961篇
特种医学   6097篇
外国民族医学   32篇
外科学   15934篇
综合类   27946篇
现状与发展   37篇
一般理论   12篇
预防医学   12692篇
眼科学   2624篇
药学   15293篇
  146篇
中国医学   8859篇
肿瘤学   10612篇
  2024年   455篇
  2023年   1617篇
  2022年   4253篇
  2021年   6082篇
  2020年   4577篇
  2019年   3790篇
  2018年   4006篇
  2017年   4257篇
  2016年   4184篇
  2015年   6414篇
  2014年   8106篇
  2013年   8607篇
  2012年   12634篇
  2011年   13518篇
  2010年   10446篇
  2009年   8788篇
  2008年   10134篇
  2007年   10078篇
  2006年   8999篇
  2005年   8037篇
  2004年   6026篇
  2003年   5720篇
  2002年   4846篇
  2001年   3097篇
  2000年   2375篇
  1999年   1524篇
  1998年   958篇
  1997年   930篇
  1996年   638篇
  1995年   572篇
  1994年   485篇
  1993年   306篇
  1992年   282篇
  1991年   237篇
  1990年   167篇
  1989年   138篇
  1988年   105篇
  1987年   91篇
  1986年   89篇
  1985年   48篇
  1984年   54篇
  1983年   32篇
  1982年   28篇
  1981年   23篇
  1980年   24篇
  1979年   33篇
  1978年   22篇
  1975年   17篇
  1973年   16篇
  1972年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
急诊室是基层医院工作的窗口,护理管理在急救工作中起着至关重要的作用。因此,基层医院对急诊护理管理提出了完善管理制度,各种物品、药品、器材做到“四定三及时”;急诊科设置集中,标志醒目;根据工作特点,严格要求护士;合理安排班次,保证充足的人力资源;加强护士急救技术和心理素质的培训,提高护理质量;不断提高护理管理者的自身素质等要求。  相似文献   
62.
BACKGROUND: During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin (PRL) and may promote formation of prolactin neoplasia in pituitary anterior lobe. OBJECTIVE: To observe the effect of diethylstilbestrol (DES) on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats. DESIGN: Observational contrast animal study. SETTING: Beijing Neurosurgical Institute. MATERIALS: A total of 21 female Wistar rats, 3 weeks old weighing 70–80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at (24±1)℃ and a humidity of (55±5)%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan. METHODS: The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil (1 mL/kg, twice a week) for 16 weeks; DES group, where animals were administered with DES (5 mg/kg, twice a week) for 16 weeks; DES + vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil (1 mL/kg, twice a week) for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. MAIN OUTCOME MEASURES: ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue. RESULTS: All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination: Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone (ACTH) was increased in both DES group and DES + vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES + vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue: Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissues were confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES + vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES. CONCLUSION: A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe.  相似文献   
63.
Research evidence that corticotropin-releasing factor (CRF) plays a role in the pathophysiology of major depressive disorder (MDD) has accumulated over the past 20 years. The elevation of lumbar cerebrospinal fluid (CSF) concentrations of CRF decreased responsiveness of pituitary CRF receptors to challenge with synthetic CRF, and increased levels of serum cortisol in MDD subjects support the hypothesis that CRF is chronically hypersecreted in at least the endocrine circuits of the hypothalamic-pituitary-adrenal (HPA) axis and may also involve other CRF brain circuits mediating emotional responses and/or arousal. One such circuit includes the excitatory CRF input to the locus coeruleus (LC), the major source of norepinephrine in the brain. Furthermore, there are now reports of decreased levels of CRF in lumbar CSF from MDD patients after symptom relief from chronic treatment with antidepressant drugs or electroconvulsive therapy. Whether this normalization reflects therapeutic effects on both endocrine- and limbic-associated CRF circuits has not yet been effectively addressed. In this brief report, we describe increased concentrations of CRF-like immunoreactivity in micropunches of post-mortem LC from subjects with MDD symptoms as established by retrospective psychiatric diagnosis compared to nondepressed subjects matched for age and sex.  相似文献   
64.
颅面联合入路切除颅眶鼻沟通瘤   总被引:4,自引:0,他引:4  
本文报告了颅面联合入路成功切除颅眶鼻沟通瘤5例,包括上颌窦腺鳞癌及胚胎型横纹肌肉瘤各1例,嗅神经母细胞瘤2例,分化好的软骨肉瘤1例。重点讨论了手术方法,眼球保留及颅底修复等问题。  相似文献   
65.
目的 观察东莨菪碱对大鼠下丘脑室核精氨酸升压素的影响。方法 以不同浓度Scop推挽灌流大鼠下丘脑室旁核 结果 扣留出液中精氨酸升压素含量随推挽时间延长而增多。结论Scop可促进PVN释放内源性AVP,这对了解Scop抗休克的机理有重大的意义。  相似文献   
66.
钩体基因疫苗对豚鼠延髓原癌基因表达的影响   总被引:1,自引:1,他引:0  
张燕华  李峻 《华西医学》1998,13(2):166-169
我们的研究已表明,赖型017株钩体外膜疏水蛋白OmpL39是稳定的免疫原,在此我们分别用OmpL39与钩体死菌苗和生理盐水对照免疫豚鼠,研究OmpL39的免疫保护作用和免疫机理,对OmpL39的抗原特异性刺激引起中枢原癌基因(Cfos基因)表达进行了观察。结果表明,OmpL39在豚鼠体内能产生高效价的阳性抗体,免疫保护率为100%。在OmpL39对中枢Cfos基因表达的影响中,我们观察到OmpL39免疫的豚鼠较空白和死菌苗组Cfos表达明显少于死菌苗组和空白对照组(p<005)。提示OmpL39能特异性地抑制Cfos基因的表达,减轻强毒钩体对动物体内的病理损伤,有较死菌苗强的免疫保护作用。  相似文献   
67.
肾移植前后男性性生活状况比较   总被引:7,自引:5,他引:2  
目的 :探讨肾移植前后男性性生活质量的变化。 方法 :将 86例男性肾移植病人分为低年龄组 (2 5~ 35岁 ,35例 )、中年龄组 (36~ 45岁 ,2 9例 )、高年龄组 (46~ 5 5岁 ,2 2例 ) 3组 ,分别调查病人患病前后、肾移植术后性生活能力、频率、性生活满意程度等性生活状况。 结果 :86例病人患病前均有性生活能力 ,患病后有性生活能力的 :低年龄组、中年龄组、高年龄组分别为 2 8.6 %,13.8和 9.1%。肾移植术后有性生活能力的 :低年龄组、中年龄组、高年龄组分别为 88.6 %、75 .9%和 6 3.6 %。 结论 :肾移植术后的性生活质量明显好于患病后 ,年龄越轻、恢复的越理想。  相似文献   
68.
阎俊 《护理研究》2007,21(15):1404-1405
目前,我国医疗总费用的增长速度大大超过了国民经济和财政收入的增长速度[1]。卫生经费投入不足,药费居高不下,政府、企业不堪重负,医疗制度改革势在必行。成本核算是医院经济管理的基础工作,核算工作的深度和层次直接影响医院成本管理的成效。1医疗成本核算的概念医疗成本是卫生服务过程中所发生的物化劳动和活劳动耗费的总和。它由以下6大类成本构成:劳务费、业务费、公务费、原材料费、固定资产折旧费和管理费。医疗成本核算是按照《医院财务制度》有关成本费用开支范围的规定,核算医院在医疗服务过程中所支出的物质消耗、劳务报酬以及有…  相似文献   
69.
停跳或不停跳心脏手术对血清 S-100B蛋白表达的影响   总被引:2,自引:1,他引:1  
【目的】研究心脏手术围术期血清S-100B蛋白表达及其与停跳或不停跳心肺转流方式和时间的关系。【方法】体外循环心脏手术患者23例,测转流前、转流10min、转流末、转流后24h的血清S-100B蛋白表达水平。【结果】①血清S-100B蛋白质量浓度在体外循环前后动态变化:转流前(M)为0.27μg/L,转流10min后升至0.57μg/L(P<0.01),转流末达峰值1.80μg/L(P<0.01),转流后24h降为0.22μg/L(P>0.05)。转流末的血清S-100B蛋白质量浓度与转流时间呈正相关(r=0.488,P<0.05)。②停跳组(n=6)转流前、转流10min、转流末、转流后24h平均血清S-100B蛋白质量浓度分别为(0.17±0.09)μg/L、(0.48±0.13)μg/L、(1.65±0.52)μg/L和(0.19±0.04)μg/L,不停跳组(n=6)分别为(0.26±0.14)μg/L、(0.71±0.41)μg/L、(1.59±0.84)μg/L和(0.23±0.11)μg/L,两组差别无统计学意义(P>0.05)。【结论】体外循环可导致血清S-100B蛋白表达增高,其表达水平与心肺转流时间呈正相关,但与停跳或不停跳转流方式无关。  相似文献   
70.
目的:探讨经尿道等离子前列腺双极汽化电切术(TUPKVP)治疗前列腺增生的效果。方法:回顾性分析580例良性前列腺增生(BPH)患者行TUPKVP的临床资料。结果:中转开放手术2例,切除前列腺组织10~80 g,平均32.5 g。手术时间25~150 min,平均60 min,术中输血10例,无电切综合征(TURS)发生。术后随访2~36个月,患者最大尿流率升高,IPSS症状评分值降低,排尿通畅,疗效好,并发症少。结论:TUPKVP出血少,手术安全,疗效确切,是治疗前列腺增生的有效方法。  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