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   64611篇
  免费   6239篇
  国内免费   4198篇
耳鼻咽喉   615篇
儿科学   744篇
妇产科学   600篇
基础医学   7678篇
口腔科学   1066篇
临床医学   7891篇
内科学   10033篇
皮肤病学   753篇
神经病学   3663篇
特种医学   2947篇
外国民族医学   26篇
外科学   6718篇
综合类   10753篇
现状与发展   17篇
一般理论   8篇
预防医学   4076篇
眼科学   1633篇
药学   6963篇
  70篇
中国医学   3504篇
肿瘤学   5290篇
  2024年   76篇
  2023年   808篇
  2022年   1367篇
  2021年   3098篇
  2020年   2466篇
  2019年   2160篇
  2018年   2264篇
  2017年   2116篇
  2016年   2150篇
  2015年   3163篇
  2014年   3754篇
  2013年   3596篇
  2012年   5247篇
  2011年   5604篇
  2010年   3940篇
  2009年   3048篇
  2008年   3705篇
  2007年   3713篇
  2006年   3397篇
  2005年   3376篇
  2004年   2413篇
  2003年   2432篇
  2002年   2091篇
  2001年   1553篇
  2000年   1270篇
  1999年   1266篇
  1998年   733篇
  1997年   723篇
  1996年   492篇
  1995年   528篇
  1994年   414篇
  1993年   232篇
  1992年   344篇
  1991年   265篇
  1990年   239篇
  1989年   226篇
  1988年   150篇
  1987年   145篇
  1986年   148篇
  1985年   91篇
  1984年   52篇
  1983年   27篇
  1982年   32篇
  1981年   23篇
  1980年   15篇
  1979年   18篇
  1974年   8篇
  1973年   13篇
  1972年   9篇
  1969年   12篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
1.
目的探讨脊髓小脑共济失调2型(SCA2)致病基因ATXN2异常等位基因中间重复个体的表型和分子遗传学特点。方法针对2005—2018年中日友好医院神经科运动障碍与神经遗传病研究中心收集的1383个常染色体显性遗传共济失调家系的先证者和部分家系成员,采用荧光标记毛细管电泳片段分析方法进行动态突变检测,对携带ATXN2基因中间重复的个体进行临床表型和遗传特征分析。结果共检出163个家系(包含先证者和家系成员共203人)携带异常扩展的ATXN2基因CAG重复序列,其中93个家系中有107例的异常扩展等位基因重复次数在29~34次之间。在其中的20个亲子对中,父系遗传16个,异常等位基因的代间扩展增加0~28次,母系遗传4个,异常等位基因的代间扩展增加0~4次。结论对于临床拟诊SCA2家系患者,需对其亲代或成年子代个体进行ATXN2基因检测,以免漏诊。动态突变基因检测有助于识别中间重复的个体,对明确家系致病基因和遗传咨询至关重要。  相似文献   
2.
目的 借助网络药理学的方法,探究两组王琦教授新冠肺炎预防方(简称预防方)预防新型冠状病毒肺炎(COVID-19)的分子靶点和机制。方法 通过TCMSP数据库检索并筛选其活性成分及其作用靶点,通过Uniprot数据库进行蛋白标准化处理。从Genecards数据库中以“Novel coronavirus pneumonia”为关键词搜索获取COVID-19的靶标,构建相交靶点韦恩图。通过cytoscape3.7.2构建PPI蛋白互作网络,寻找富集数目最多的靶点。通过R语言对预防方治疗COVID-19的靶点进行GO和KEGG富集分析,并绘制气泡图。结果 预防方与新冠肺炎相关靶点涉IL-6、TNF、CXCL8、VEGFA、MMP9;GO功能富集分析分别获得53、57条通路;27、29条KEGG相关信号通路。结论 王琦教授新冠肺炎预防方中的主要活性成分为槲皮素、山奈酚、木犀草素、β-谷甾醇、植物甾醇等,可能通过作用于IL-6、TNF、CXCL8、VEGFA、MMP9、CXCL8、IL10、CCL2、IL1B等靶点和介导TNF信号通路、T细胞受体信号通路、Toll样受体信号通路等发挥作用,从而促进免疫反应、炎症反应及细菌防御反应,预防COVID-19。  相似文献   
3.
Cantharidin (CTD) is an effective antitumor agent. However, it exhibits significant hepatotoxicity, the mechanism of which remains unclear. In this study, biochemical and histopathological analyses complemented with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabolomic analysis of bile acids (BAs) were employed to investigate CTD-induced hepatotoxicity in rats. Sixteen male and female Sprague–Dawley rats were randomly divided into two groups: control and CTD (1.0 mg/kg) groups. Serum and liver samples were collected after 28 days of intervention. Biochemical, histopathological, and BA metabolomic analyses were performed for all samples. Further, the key biomarkers of CTD-induced hepatotoxicity were identified via multivariate and metabolic pathway analyses. In addition, metabolite–gene–enzyme network and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to identify the signaling pathways related to CTD-induced hepatotoxicity. The results revealed significantly increased levels of biochemical indices (alanine aminotransferase, aspartate aminotransferase, and total bile acid). Histopathological analysis revealed that the hepatocytes were damaged. Further, 20 endogenous BAs were quantitated via UHPLC-MS/MS, and multivariate and metabolic pathway analyses of BAs revealed that hyocholic acid, cholic acid, and chenodeoxycholic acid were the key biomarkers of CTD-induced hepatotoxicity. Meanwhile, primary and secondary BA biosynthesis and taurine and hypotaurine metabolism were found to be associated with the mechanism by which CTD induced hepatotoxicity in rats. This study provides useful insights for research on the mechanism of CTD-induced hepatotoxicity.  相似文献   
4.
The present study aimed at examining the curative effect of modified posterior operation on treatment of Kümmell''s disease.About 30 patients of Kümmell''s disease with complete image and clinical data treated during June 2004 to July 2013 were conducted with anterior and posterior approaches, respectively. Kyphotic Cobb angle, fractured vertebra wedge angle, and the anterior and posterior heights of fractured vertebra were all measured through x-ray before and after operation, and the pain visual analog scale (VAS) was determined for evaluating the effect of operations. The injury and restoration of neurological function were assessed using Frankel classification.Patients in group A were treated with anterior operation, whereas group B was posterior operation. Postoperatively, VAS score, kyphotic Cobb angle, anterior vertebra height, and pathologic vertebra wedge angle were all significantly improved in patients with Kümmell''s disease receiving modified posterior operation (group B). Similar results were also observed in patients with anterior operation. The improvement of VAS and correction rate of kyphotic Cobb angle indicated equivalent effects of posterior and anterior operations. Meanwhile, alleviated neurological function damage was observed in 2 groups. Relevant factor analysis illustrated that there was no significant correlation of the severity and improvement rate of pain symptoms with age, medical history, anterior and posterior vertebra heights, kyphotic Cobb angle, and pathological vertebra wedge angle.Compared with traditional anterior approach, modified posterior operation, adopting transpedicular vertebral body grafting combined with vertebral pedicle screw fixation, could produce equivalent effects on kyphosis correction, pain relief, and improvement of neurological function in patients with Kümmell''s disease.  相似文献   
5.
目的探讨脑卒中患者急性应激障碍发生现状及影响因素。方法采用斯坦福急性应激反应问卷对349例脑卒中住院患者进行调查。结果共163例(46.70%)患者发生急性应激障碍;Logistic回归分析结果显示,患者性格、是否存在偏瘫及是否吞咽功能障碍是脑卒中患者发生急性应激障碍的主要影响因素(P0.05,P0.01)。结论脑卒中患者急性应激障碍发生率较高,内向性格及存在偏瘫和吞咽功能障碍的患者更容易发生急性应激障碍。医护人员应及时为高危患者提供个体化治疗及预见性护理,防止脑卒中患者发生急性应激障碍。  相似文献   
6.
7.
Patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) have poor prognosis, and the efficacy of chemotherapy plus tyrosine kinase inhibitors (TKIs) followed by mismatched donor stem cell infusion (microtransplantation, MST) has not been determined. We retrospectively summarized 45 patients including 11 undergoing MST with TKIs, 17 receiving allogeneic transplant and 17 undergoing chemotherapy with TKIs. Improved 4-year overall survival rate was observed in the MST group (91%) compared with either transplant group (31%, P = .005) or chemotherapy group (36%, P = .013). The MST group also had higher 2-year and 4-year leukemia-free survival rates (91% and 72%, respectively) compared with either transplant group (33%, P = .005 and 33%, P = .021, respectively) or chemotherapy group (41%, P = .017 and 31%, P = .023, respectively). 2-year and 4-year cumulative incidences of hematologic relapse were lower in the MST group (9% and 28%, respectively) compared with those in the chemotherapy group (56%, P = .025 and 67%, P = .034, respectively). In patients undergoing MST, donor microchimerism was detected (1.07 × 10-5 to 6.6 × 10-4 copies from 9 to 1499 days) in 7 patients, and donor/patient-derived HLA*0201/2402+WT1+CD8+ T cells were found from 0.05% to 0.67% in 6 patients. MST may provide a favorable treatment for patients with Ph+ ALL.  相似文献   
8.
目的探讨神经内镜辅助下经鼻蝶入路切除鞍区肿瘤的方法和优势。方法回顾性分析30例鞍区肿瘤病人的临床资料,垂体腺瘤26例(其中无功能垂体腺瘤6例、泌乳素瘤16例、垂体生长激素腺瘤4例),拉克囊肿1例,胆脂瘤1例,脑膜瘤1例,颅咽管瘤1例。采用神经内镜辅助下经鼻蝶入路手术切除肿瘤。结果肿瘤全切27例,部分切除3例。术后3例发生脑脊液鼻漏,经腰大池持续引流后痊愈。无死亡病例。随访3~6个月,病人恢复良好。结论在神经内镜辅助下经鼻蝶入路治疗鞍区肿瘤,较单纯的显微镜手术治疗创伤更小,肿瘤全切率更高。  相似文献   
9.
ABSTRACT

Purpose

Work-related eye injuries have been reported with a variety of epidemiologic and clinical characteristics. We aimed to identify epidemiologic characteristics of work-related eye injuries and risk factors associated with severe injury in a large metropolitan city.  相似文献   
10.
【摘要】 报道临床症状不典型的家族性黑棘皮病1家系。先证者女,4岁,自1周岁时,颈部、腹部出现黑色斑片,近年来逐渐扩大至唇周、躯干前部。腹部皮肤全反式共聚焦显微镜检查可见乳头环下延扭曲及沟壑结构,乳头环内可见中高折光颗粒结构。先证者父亲及祖母既往有类似病史,但随着年龄增长色素沉着自发性消退,仅有局部皮纹增粗。采集先证者及父母、祖母外周血,对先证者外周血DNA行Panel靶向测序,结果显示,先证者存在FGFR3基因14号外显子c.1949A>C(p.Lys650Thr)错义突变,Sanger测序验证证实先证者及其父亲和祖母均存在此突变。诊断:家族性黑棘皮病。  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