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   234810篇
  免费   15255篇
  国内免费   988篇
耳鼻咽喉   2524篇
儿科学   5998篇
妇产科学   4417篇
基础医学   29305篇
口腔科学   4320篇
临床医学   24055篇
内科学   49571篇
皮肤病学   3226篇
神经病学   23655篇
特种医学   10110篇
外国民族医学   13篇
外科学   37040篇
综合类   2537篇
现状与发展   1篇
一般理论   177篇
预防医学   16519篇
眼科学   5529篇
药学   15494篇
  1篇
中国医学   319篇
肿瘤学   16242篇
  2023年   1335篇
  2022年   2189篇
  2021年   5334篇
  2020年   3046篇
  2019年   5054篇
  2018年   6056篇
  2017年   4446篇
  2016年   4853篇
  2015年   5733篇
  2014年   8348篇
  2013年   11246篇
  2012年   17280篇
  2011年   18014篇
  2010年   10070篇
  2009年   9314篇
  2008年   15863篇
  2007年   16653篇
  2006年   16194篇
  2005年   16052篇
  2004年   15104篇
  2003年   13784篇
  2002年   13185篇
  2001年   1927篇
  2000年   1427篇
  1999年   2001篇
  1998年   2783篇
  1997年   2213篇
  1996年   1923篇
  1995年   1762篇
  1994年   1527篇
  1993年   1493篇
  1992年   982篇
  1991年   926篇
  1990年   783篇
  1989年   742篇
  1988年   679篇
  1987年   614篇
  1986年   636篇
  1985年   678篇
  1984年   909篇
  1983年   787篇
  1982年   1033篇
  1981年   965篇
  1980年   836篇
  1979年   465篇
  1978年   514篇
  1977年   448篇
  1976年   421篇
  1975年   316篇
  1974年   314篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes.  相似文献   
63.
64.
65.
Der Freie Zahnarzt - Rechtstipp. Für angebliche Behandlungs- und Aufklärungsfehler bleiben die Zivilgerichte auch bei Kostenerstattung zuständig. Eine kuriose, wiewohl wichtige...  相似文献   
66.
67.
The presented case reports on successful treatment with everolimus in a neonate with left ventricular giant rhabdomyoma. The authors used a different dosage regime compared to literature and documented rapid tumor regression by 3D echocardiography.  相似文献   
68.
ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity.  相似文献   
69.
70.
Radiolabeled octreotide analogs (Oct) and metaiodobenzylguanidine (MIBG) offer 2 different approaches for imaging and targeting metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NET). Despite successful establishment of the revised World Health Organization (WHO) classification, which distinguishes between low- and high-grade malignant GEP-NET, there is a lack of scintigraphic studies comparing uptake behavior on the basis of this categorization. This study aims to define predisposing factors of tracer uptake for both imaging principles implementing the updated tumor criteria of the current WHO classification. METHODS: Fifty-seven consecutive patients with histologically confirmed metastatic GEP-NET evaluated with both 111In-pentetreotide and 123I/131I-MIBG scintigraphy were included in this study. Intensity of tracer uptake was graded according to the different metastatic regions. Patients were classified as overall positive when avid uptake in the clinically relevant tumor lesions was present. Correlation was tested between the proportion of positive patients and tumor origin, function, and malignancy. RESULTS: Overall, 52 patients (91.2%) were Oct positive and 28 patients (49.1%) were MIBG positive. The proportion of tracer-positive patients was significantly higher (P < 0.05) in low-grade malignant tumors for both tracers and in functioning as well as in gastroenteral NET for MIBG. Five patients were negative for both tracers. None of the Oct-negative patients proved to be MIBG positive. CONCLUSION: Oct affinity is observed with high frequency throughout the subgroups of metastatic GEP-NET, whereas corresponding MIBG uptake is overall less prevalent and more group dependent. Tumor differentiation significantly impacts both Oct and MIBG uptake, whereas functionality predisposes only for MIBG accumulation. Though clearly inferior to Oct-based radioimaging in most GEP-NET, MIBG achieves a remarkable rate of radioligand accumulation in functioning midgut enterochromaffin cell metastases (>80% of patients positive). These results may have implications for patient management and potentially for selection and performance of targeted therapy.  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