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   1563篇
  免费   134篇
  国内免费   17篇
耳鼻咽喉   7篇
儿科学   62篇
妇产科学   17篇
基础医学   222篇
口腔科学   34篇
临床医学   189篇
内科学   288篇
皮肤病学   39篇
神经病学   155篇
特种医学   156篇
外科学   114篇
综合类   45篇
预防医学   186篇
眼科学   22篇
药学   56篇
中国医学   2篇
肿瘤学   120篇
  2023年   7篇
  2022年   8篇
  2021年   28篇
  2020年   18篇
  2019年   33篇
  2018年   31篇
  2017年   33篇
  2016年   26篇
  2015年   42篇
  2014年   55篇
  2013年   59篇
  2012年   69篇
  2011年   52篇
  2010年   75篇
  2009年   67篇
  2008年   57篇
  2007年   66篇
  2006年   79篇
  2005年   52篇
  2004年   51篇
  2003年   51篇
  2002年   45篇
  2001年   38篇
  2000年   37篇
  1999年   51篇
  1998年   59篇
  1997年   54篇
  1996年   50篇
  1995年   33篇
  1994年   44篇
  1993年   37篇
  1992年   26篇
  1991年   22篇
  1990年   26篇
  1989年   32篇
  1988年   26篇
  1987年   28篇
  1986年   15篇
  1985年   16篇
  1984年   9篇
  1983年   11篇
  1982年   15篇
  1981年   9篇
  1980年   16篇
  1979年   3篇
  1978年   5篇
  1977年   13篇
  1976年   7篇
  1975年   6篇
  1956年   3篇
排序方式: 共有1714条查询结果,搜索用时 15 毫秒
1.
Endosonography in diagnosing and staging duodenal villous adenoma.   总被引:1,自引:0,他引:1       下载免费PDF全文
T L Tio  L H Sie  P C Verbeek  L T D Wit    G N Tytgat 《Gut》1992,33(4):567-568
Endosonography was carried out in a patient with an extensive juxtapapillary tumour. Radiology and endoscopy were unable to distinguish a villous adenoma from an invasive carcinoma. Endosonography revealed a mucosal hypoechoic tumour without penetration into the submucosa and muscularis propria. The common bile duct, pancreatic duct, and pancreas were normal. Lymph node abnormalities were not found. Based on the endosonography findings, local surgical tumour resection was undertaken instead of a Whipple procedure. The histology of the resected specimen confirmed the endosonography diagnosis.  相似文献   
2.
3.
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.  相似文献   
4.
A double or bilobar gallbladder is a rare congenital anomaly. If not recognized during preoperative evaluation or operation, it can cause severe complications. We describe two cases in which a second operation had to be performed because of the presence of a second or bilobar gallbladder that was not recognized in the preoperative evaluation and during (laparoscopic) cholecystectomy. The types of anomalies, the concomitant pathology, and treatment are discussed.  相似文献   
5.
We studied the reported frequencies of clinical complaints of neuromuscular hyperexcitability (muscle cramps and fasciculations) in random samples of 527 Dutch adults, who were and 253 Dutch adults, who were not suffering from musculoskeletal pain and tenderness. Data were collected by telephone-interview and by self-administered questionnaire. Muscle cramps and fasciculations were recorded more frequently in the category that suffered from musculoskeletal pain (p less than 0.001). This association warrants further investigation into the possible intrinsic role of neuromuscular hyperexcitability in musculoskeletal pain and primary fibromyalgia.  相似文献   
6.
7.
8.
Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced thoracic cavity. In the most common subtype (TD1), femurs are curved, while in TD2, straight femurs are associated with cloverleaf skull. Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene were identified in both subtypes. While TD2 was accounted for by a single recurrent mutation in the tyrosine kinase 2 domain, TD1 resulted from either stop codon mutations or missense mutations in the extracellular domain of the gene. Here, we report the identification of FGFR3 mutations in 25/26 TD cases. Two novel missense mutations (Y373C and G370C) were detected in 8/26 and 1/26 TD1 cases respectively. Both mutations created cysteine residues in the juxta extramembrane domain of the receptor. Sixteen cases carried the previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically homogeneous condition and give additional support to the view that newly created cysteine residues in the extracellular domain of the protein play a key role in the severity of the disease.   相似文献   
9.
BACKGROUND: Lipid transfer proteins (LTPs) are small molecules of approximately 10 kD that demonstrate high stability. They have recently been identified as allergens in the Rosaceae subfamilies of the Prunoideae (peach, apricot, plum) and of the Pomoideae (apple). They belong to a family of structurally highly conserved proteins that are also present in non-Rosaceae vegetable foods. OBJECTIVE: The aim of this study was to investigate the cross-reactivity to non-Rosaceae LTPs, and to study the role of protein stability in allergenicity. METHODS: Thirty-eight patients with a positive SPT to Rosaceae fruit extracts enriched for LTP were characterized by interview and SPT. To investigate IgE cross-reactivity between Rosaceae and non-Rosaceae LTPs, RAST and RAST inhibition as well as ELISA and ELISA inhibition were performed, using whole food extracts and purified LTPs. Both purified natural LTPs (peach, carrot and broccoli) and Pichia pastoris recombinant LTPs (carrot and wheat) were included. Pepsin digestion was used to address the role of stability in the allergenicity of LTPs. RESULTS: IgE antibodies to Rosaceae LTPs reacted to a broad range of vegetable foods, including Gramineae (cereals), Leguminosae (peanut), Juglandaceae (walnut), Anacardiaceae (pistachio), Brassicaceae (broccoli), Umbelliferae (carrot, celery), Solanaceae (tomato), Cucurbitaceae (melon), and Actinidiaceae (kiwi). Binding and inhibition studies with purified natural and recombinant LTPs confirmed their role in this cross-reactivity. Many of these cross-reactivities were accompanied by clinical food allergy, frequently including systemic reactions. Antibody binding to LTP was shown to be resistant to pepsin treatment of whole extract or purified LTP. CONCLUSION: LTP is a pan-allergen with a degree of cross-reactivity comparable to profilin. Due to its extreme resistance to pepsin digestion, LTP is a potentially severe food allergen.  相似文献   
10.
Amyloid-beta (Abeta) deposition in the cerebral arterial and capillary walls is one of the characteristics of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type. In vitro, Abeta1-40, carrying the "Dutch" mutation (DAbeta1-40), induced reproducible degeneration of cultured human brain pericytes (HBP), by forming fibrils at the cell surface. Thus, this culture system provides an useful model to study the vascular pathology seen in Alzheimer's disease. In this study, we used this model to investigate the effects of insulin on Abeta-induced degeneration of HBP, as it has been mentioned previously that insulin is able to protect neurons against Abeta-induced cell-death. The toxic effect of DAbeta1-40 on HBP was inhibited by insulin in a dose-dependent matter. Insulin interacted with Abeta and inhibited fibril formation of Abeta in a cell-free assay, as well as at the cell surface of HBP. Our data indicate that the formation of a fibril network is essential for Abeta-induced cell death in HBP. Additionally, insulin may be involved in the regulation of Abeta fibrillization in AD.  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