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   86845篇
  免费   7859篇
  国内免费   4315篇
耳鼻咽喉   952篇
儿科学   1437篇
妇产科学   972篇
基础医学   9359篇
口腔科学   1560篇
临床医学   10617篇
内科学   12780篇
皮肤病学   1990篇
神经病学   4008篇
特种医学   4115篇
外国民族医学   22篇
外科学   8224篇
综合类   13820篇
现状与发展   17篇
一般理论   15篇
预防医学   7112篇
眼科学   1932篇
药学   9444篇
  80篇
中国医学   4941篇
肿瘤学   5622篇
  2024年   257篇
  2023年   1100篇
  2022年   2795篇
  2021年   3848篇
  2020年   2894篇
  2019年   2479篇
  2018年   2635篇
  2017年   2637篇
  2016年   2692篇
  2015年   4217篇
  2014年   5277篇
  2013年   5618篇
  2012年   8050篇
  2011年   8262篇
  2010年   6025篇
  2009年   5030篇
  2008年   5775篇
  2007年   5431篇
  2006年   5144篇
  2005年   4404篇
  2004年   3183篇
  2003年   2720篇
  2002年   2337篇
  2001年   1339篇
  2000年   1063篇
  1999年   792篇
  1998年   434篇
  1997年   467篇
  1996年   317篇
  1995年   291篇
  1994年   259篇
  1993年   163篇
  1992年   190篇
  1991年   180篇
  1990年   125篇
  1989年   85篇
  1988年   75篇
  1987年   54篇
  1986年   53篇
  1985年   33篇
  1984年   32篇
  1983年   36篇
  1982年   25篇
  1981年   19篇
  1980年   18篇
  1979年   17篇
  1978年   12篇
  1974年   12篇
  1972年   18篇
  1971年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
搭建基础平台是改传统三年制医学教学“1+1+1”模式为“1+1”模式,为以“市场为导向,就业为中心”的高职教学进行多向培养提供条件,既拓宽教学渠道,适应市场需求,解决学生就业问题,同时又有利于学校发展,符合教学新模式量展要求。  相似文献   
82.
鹿鞭的药理研究与临床应用展望   总被引:1,自引:1,他引:0  
综述了近年来传统中药鹿鞭的药理作用以及临床应用,资料表明鹿鞭具有抗衰老、抗疲劳、增强机体免疫、促进伤口愈合等药理作用,且临床疗效突出,是具有开发前景的中药材。  相似文献   
83.
BACKGROUND & AIMS: The aim of this study was to assess the validity of frozen section analysis of endoscopic mucosal resection (EMR) specimens from Barrett's esophagus as compared with permanent sections for the detection of neoplasia. Frozen sections help to give immediate feedback for surgical procedures. It has not been determined whether EMR can be adequately interpreted by using frozen sections to aid endoscopists in completely resecting neoplastic lesions. METHODS: EMR specimens from Barrett's esophagus with high-grade dysplasia (HGD) and/or carcinoma were tested by frozen section. Pathologists evaluated EMR specimens for the depth of invasion as well as the appearance of clear margins of resection. The kappa statistic was calculated to assess the degree of agreement between the frozen section and permanent section diagnoses. RESULTS: Twenty-three consecutive patients underwent 30 EMRs with frozen section diagnosis. Frozen section revealed a carcinoma in 7 specimens (23%) and dysplasia in 20 (66%). Permanent sections found carcinoma in 8 specimens (26%), dysplasia in 19 specimens (63%), and normal or nondysplastic Barrett's esophagus in the remainder. The kappa statistic for the depth of invasion of EMR specimens was 0.93 (near perfect agreement). The kappa statistic for the margins of the EMR specimens was 0.80 (excellent agreement). CONCLUSIONS: This study indicated that frozen section analysis of esophageal EMR specimens is valid as compared with permanent section. This technique might allow rapid evaluation about the degree and depth of involvement of cancers. This allows physicians to make decisions regarding further therapy if margins are involved or decrease the use of EMR for histologically benign-appearing lesions.  相似文献   
84.
OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.  相似文献   
85.
86.
Glial glutamate transporter-1 (GLT-1) plays an essential role in removing glutamate from the extracellular space and maintaining the glutamate below neurotoxic level in the brain. To explore whether GLT-1 plays a role in the acquisition of brain ischemic tolerance (BIT) induced by cerebral ischemic preconditioning (CIP), the present study was undertaken to observe in vivo changes in the expression of GLT-1 and glial fibrillary acidic protein (GFAP) in the CA1 hippocampus during the induction of BIT, and the effect of dihydrokainate (DHK), an inhibitor of GLT-1, on the acquisition of BIT in rats. Immunohistochemistry for GFAP showed that the processes of astrocytes were prolonged after a CIP 2 days before the lethal ischemic insult, which could protect pyramidal neurons in the CA1 hippocampus against delayed neuronal death induced normally by lethal ischemic insult. The prolonged processes extended into the area between the pyramidal neurons and tightly surrounded them. These changes made the pyramidal layer look like a 'shape grid'. Simultaneously, the prolonged and extended processes showed a great deal of GLT-1. Western blotting analysis showed significant upregulation of GLT-1 expression after the CIP, especially when it was administered 2 days before the subsequent lethal ischemic insult. Neuropathological evaluation by thionin staining showed that DHK dose-dependently blocked the protective role of CIP against delayed neuronal death induced normally by lethal brain ischemia. It might be concluded that the surrounding of pyramidal neurons by astrocytes and upregulation of GLT-1 induced by CIP played an important role in the acquisition of the BIT induced by CIP.  相似文献   
87.
腰椎间盘突出症早期手术并发症的回顾性分析   总被引:1,自引:1,他引:0  
腰椎间盘突出是腰腿痛的主要原因,因患病率高,手术开展较为普及,关于其手术后并发症的相关报导也逐渐增多。为了进一步了解这些并发症的发生原因,我们将1993年2月至2004年12月手术治疗腰椎间盘突出症768例中所发生的74例早期并发症进行回顾性分析,针对手术的危险因素提出相应的  相似文献   
88.
目的探讨伴有齿槽嵴裂的单侧唇裂术后继发鼻畸形的修复方法。方法对34例伴有齿槽嵴裂的单侧唇裂术后继发畸形的患者,在行齿槽嵴植骨的同时,行彻底的鼻整形手术。结果术后随访1~3年,植骨区成活良好,鼻畸形较整形前明显改善,接近正常外形,效果满意。结论在行齿槽嵴植骨的同时,行彻底的鼻整形手术,能够取得满意的效果,并且节省了医疗费用,缩短了治疗时间。  相似文献   
89.
Torsion of greater omentum is a rare cause of acute abdomen. However, it should be included in the differential diagnoses in addition to acute cholecystitis, acute appendicitis, cecal diverticulitis, and other variable causes of acute abdomen. Diagnosis is usually made at laparotomy for suspected appendicitis. In some cases, computed tomography demonstrates a successful preoperative detection of omental torsion. We report a case of surgically and pathologically proven torsion with subsequent infarction of greater omentum presented as an acute abdominal pain.  相似文献   
90.
大肠癌组织中MMP-2、MMP-7的基因表达   总被引:3,自引:3,他引:0  
目的:观察MMP-2和MMP-7在大肠癌组织与正常组织中表达的差异.方法:取28例大肠癌组织及肿瘤周围正常组织,用RT-PCR方法检测肿瘤组织及正常组织中MMP-2和MMP-7的表达.结果:MMP-2和MMP-7在大肠癌组织中的表达率和表达水平高于周围的正常组织(P<0.05).结论:MMP-2和MMP-7可能在大肠癌的进展中起重要作用.  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