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   240976篇
  免费   15163篇
  国内免费   1001篇
耳鼻咽喉   2571篇
儿科学   6201篇
妇产科学   4504篇
基础医学   30353篇
口腔科学   4511篇
临床医学   24527篇
内科学   50449篇
皮肤病学   3582篇
神经病学   24361篇
特种医学   10426篇
外国民族医学   13篇
外科学   37689篇
综合类   2581篇
现状与发展   1篇
一般理论   177篇
预防医学   16758篇
眼科学   5580篇
药学   15901篇
  1篇
中国医学   320篇
肿瘤学   16634篇
  2023年   1357篇
  2022年   2236篇
  2021年   5423篇
  2020年   3102篇
  2019年   5103篇
  2018年   6162篇
  2017年   4534篇
  2016年   4981篇
  2015年   5851篇
  2014年   8509篇
  2013年   11436篇
  2012年   17532篇
  2011年   18252篇
  2010年   10205篇
  2009年   9454篇
  2008年   16088篇
  2007年   16885篇
  2006年   16454篇
  2005年   16287篇
  2004年   15339篇
  2003年   13983篇
  2002年   13403篇
  2001年   2187篇
  2000年   1651篇
  1999年   2189篇
  1998年   2869篇
  1997年   2274篇
  1996年   1967篇
  1995年   1824篇
  1994年   1579篇
  1993年   1559篇
  1992年   1079篇
  1991年   1025篇
  1990年   895篇
  1989年   841篇
  1988年   763篇
  1987年   691篇
  1986年   714篇
  1985年   754篇
  1984年   981篇
  1983年   843篇
  1982年   1076篇
  1981年   1004篇
  1980年   869篇
  1979年   533篇
  1978年   558篇
  1977年   492篇
  1976年   443篇
  1975年   351篇
  1974年   350篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
Introduction: Pharmacological options to address the imbalance between bone resorption and accrual in osteoporosis include anti-resorptive and osteoanabolic agents. Unique biologic pathways such as the Wnt/β-catenin pathway have been targeted in the quest for new emerging therapeutic strategies.

Areas covered: This review provides an overview of existing pharmacotherapy for osteoporosis in women and explore state-of–the-art and emerging therapies to prevent bone loss, with an emphasis on the mechanism of action, indications and side effects.

Expert opinion: Bisphosphonates appear to be a reliable and cost-effective option, whereas denosumab has introduced a simpler dosing regimen and may achieve a linear increase in bone mineral density (BMD) with no plateau being observed, along with continuous anti-fracture efficacy. Abaloparatide, a parathyroid-hormone-related peptide (PTHrP)-analogue, approved by the FDA in April 2017, constitutes the first new anabolic osteoporosis drug in the US for nearly 15 years and has also proven its anti-fracture efficacy. Romosozumab, a sclerostin inhibitor, which induces bone formation and suppresses bone resorption, has also been developed and shown a significant reduction in fracture incidence; however, concerns have arisen with regard to increased cardiovascular risk.  相似文献   

34.
35.
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   
36.
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   
37.
38.
39.
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   
40.
The repair of massive cuff defects by direct suture often is impossible. In these cases, a repair by musculo–tendineous flaps (latissimus-dorsi, pectoralis or deltoideus) is required. It was the goal of this study to evaluate the result of delta-flap repair in case of massive cuff defects with a diameter of 5 cm or more. Between 1998 and 2000 for all patients who were suffering from a massive rotator cuff tear more than 5 cm a deltoid transfer was performed. A total of 20 patients (14 male, 6 female; age: 60.9 ± 8.7 years) were available for a follow-up after 47.2 ± 8.0 (range, 36 to 60) month. The operation included an arthroscopic evaluation, acromioplasty with resection of the lateral clavicular end, and biceps tenodesis. The cuff defect was repaired by transfer a muscular flap from the anterior part of the deltoid (about 2×6 cm) into the defect. The patients subjectively rated their result—10 excellent, 9 good, and 1 poor. Preoperatively, the Constant amounted 26.3 ± 5.1 points. At follow-up, the score significantly increased to 74.5 ± 8.5 points. The acromiohumeral distance increased from 4.9 ± 1.1 to 9.2 ± 1.7 mm. In MRI examination of 11 patients all had an intact flap. Two complications (a wound hematoma and a deep infection) did not influence the result. The repair of massive rotator cuff tears by a deltoid transfer produces acceptable clinical and radiological results.  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