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   82958篇
  免费   8270篇
  国内免费   5288篇
耳鼻咽喉   839篇
儿科学   1291篇
妇产科学   707篇
基础医学   8885篇
口腔科学   1346篇
临床医学   9832篇
内科学   11251篇
皮肤病学   1327篇
神经病学   3932篇
特种医学   3509篇
外国民族医学   14篇
外科学   7812篇
综合类   15537篇
现状与发展   15篇
一般理论   5篇
预防医学   7026篇
眼科学   1657篇
药学   9492篇
  67篇
中国医学   6178篇
肿瘤学   5794篇
  2024年   394篇
  2023年   1253篇
  2022年   3054篇
  2021年   3937篇
  2020年   2887篇
  2019年   2535篇
  2018年   2648篇
  2017年   2729篇
  2016年   2724篇
  2015年   4012篇
  2014年   4779篇
  2013年   5242篇
  2012年   7162篇
  2011年   7561篇
  2010年   5525篇
  2009年   4510篇
  2008年   5138篇
  2007年   4974篇
  2006年   4578篇
  2005年   4045篇
  2004年   3042篇
  2003年   2963篇
  2002年   2532篇
  2001年   1968篇
  2000年   1515篇
  1999年   1040篇
  1998年   606篇
  1997年   552篇
  1996年   413篇
  1995年   342篇
  1994年   322篇
  1993年   207篇
  1992年   224篇
  1991年   208篇
  1990年   173篇
  1989年   138篇
  1988年   107篇
  1987年   90篇
  1986年   85篇
  1985年   50篇
  1984年   32篇
  1983年   19篇
  1982年   17篇
  1981年   23篇
  1980年   17篇
  1979年   37篇
  1978年   8篇
  1976年   8篇
  1972年   7篇
  1969年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
2.
3.
4.
BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection.METHODS. Using polychromatic flow cytometry, we evaluated the expression of immune activation markers on Mtb-specific CD4+ T cells from individuals with asymptomatic latent Mtb infection (LTBI) and ATB as well as from ATB patients undergoing anti-TB treatment.RESULTS. Frequencies of Mtb-specific IFN-γ+CD4+ T cells that expressed immune activation markers CD38 and HLA-DR as well as intracellular proliferation marker Ki-67 were substantially higher in subjects with ATB compared with those with LTBI. These markers accurately classified ATB and LTBI status, with cutoff values of 18%, 60%, and 5% for CD38+IFN-γ+, HLA-DR+IFN-γ+, and Ki-67+IFN-γ+, respectively, with 100% specificity and greater than 96% sensitivity. These markers also distinguished individuals with untreated ATB from those who had successfully completed anti-TB treatment and correlated with decreasing mycobacterial loads during treatment.CONCLUSION. We have identified host blood-based biomarkers on Mtb-specific CD4+ T cells that discriminate between ATB and LTBI and provide a set of tools for monitoring treatment response and cure.TRIAL REGISTRATION. Registration is not required for observational studies.FUNDING. This study was funded by Emory University, the NIH, and the Yerkes National Primate Center.  相似文献   
5.
6.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.  相似文献   
7.
8.
9.
本文报告3例在疼痛诊疗过程中的误诊与误治,原发病分别为病灶未明确的颈椎癌转移、脊椎结核腰大肌间沟寒性脓肿与腰骶椎恶性肿瘤,分别被误诊为颈椎病、腰肌劳损与腰肌劳损,幸及时发现,纠正了错误的治疗。因此应强调从事疼痛业务必须有扎实的通科基础,严格的检查流程与认真的工作态度。  相似文献   
10.
肝癌间质及癌旁病变的病理分析   总被引:2,自引:0,他引:2  
目的 研究肝癌间质及癌旁病变的临床病理意义。方法 在 2 0例肝癌组织标本中取 45个癌结节 ,分别在癌结节中间、癌旁肝组织等部位取组织 4块 ,连续切片 ,显微镜下观察。结果  19个结节有完整窦内皮细胞围绕癌巢 ,其中癌结节肉眼小于3cm者 13个 ,大于 3cm者 6个。 2 6个癌结节无完整窦内皮细胞围绕癌巢 ,其中癌结节直径大于 3cm者 2 4个 ,小于 3cm者 2个。2 0例中有 13例合并肝硬化 ,17例有乙型肝炎病毒感染和HBsAg阳性。 结论 病理连续切片 ,显微镜下观察肝癌间质及癌旁病变是预测肝癌患者预后的重要病理学指标  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