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   1553篇
  免费   76篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   23篇
妇产科学   11篇
基础医学   194篇
口腔科学   24篇
临床医学   281篇
内科学   151篇
皮肤病学   1篇
神经病学   449篇
特种医学   22篇
外科学   251篇
综合类   16篇
预防医学   58篇
眼科学   13篇
药学   107篇
中国医学   1篇
肿瘤学   21篇
  2021年   21篇
  2020年   10篇
  2019年   15篇
  2018年   20篇
  2017年   24篇
  2016年   18篇
  2015年   30篇
  2014年   45篇
  2013年   56篇
  2012年   76篇
  2011年   91篇
  2010年   65篇
  2009年   57篇
  2008年   109篇
  2007年   96篇
  2006年   104篇
  2005年   85篇
  2004年   84篇
  2003年   52篇
  2002年   82篇
  2001年   48篇
  2000年   46篇
  1999年   32篇
  1998年   18篇
  1997年   12篇
  1996年   14篇
  1995年   17篇
  1994年   9篇
  1993年   9篇
  1992年   26篇
  1991年   25篇
  1990年   21篇
  1989年   22篇
  1988年   15篇
  1987年   16篇
  1986年   11篇
  1985年   11篇
  1984年   13篇
  1983年   9篇
  1982年   8篇
  1981年   9篇
  1978年   7篇
  1976年   5篇
  1974年   6篇
  1973年   9篇
  1972年   6篇
  1971年   10篇
  1970年   5篇
  1969年   7篇
  1967年   5篇
排序方式: 共有1630条查询结果,搜索用时 15 毫秒
1.
Migräne     
Migraine is a prevalent disease that affects women more frequently than men. A particular trigger for migraine is the perimenstrual period. Acute migraine attacks during menstruation are treated similarly to nonmenstrual attacks, e.g., with analgesics or triptans. In women with pure menstrual migraine, short-term prophylaxis can be performed with nonsteroidal anti-inflammatory drugs (NSAIDs), estrogens, or low-dose triptans. During pregnancy migraine improves. After menopause frequency and severity of migraine attacks improve.  相似文献   
2.
3.
This paper describes performance and results of a collaborative study in which the solid-phase enzyme immunoassay was tested in order to determine specific IgE under practical conditions. All titres of specific IgE can be differentiated in a reproducible way with high significance.  相似文献   
4.
Angesichts der vielf?ltigen klinischen Klassifikationssysteme und Syndrome fehlt bislang ein repr?sentativer überblick über ?tiologie und Prognose von Hirnstamminfarkten. Aus der Deutschen Schlaganfall-Datenbank untersuchten wir daher 455 Patienten mit bildmorphologisch nachgewiesenem, akuten Hirnstamminfarkt im Vergleich zu Patienten mit anderer Infarktlokalisation. Durch Nachbefragung der Patienten nach 3 und 12 Monaten wurden au?erdem das funktionelle Ergebnis sowie die Reinsultrate erhoben.  相似文献   
5.
Sex, socioeconomic status, intelligence, a clinical symptom score, and an index of abnormal psychosocial situations as proposed by a recent WHO draft were studied as correlates of the Global Assessment of Functioning Scale (GAFS), which comprises Axis V of theDSM-III-R. Whereas all parameters correlated significantly with the GAFS score, only total symptom domain score displayed a meaningful association. It was concluded that the GAFS contributes significantly to clinical information as an independent source.
Zusammenfassung Es wurden ein klinischer Symptomwert, ein Index für abnorme psychosoziale Situationen gemäß einem unlängst erschienenen WHO-Dokument, Geschlecht, sozioökonomischer Status und Intelligenz als Korrelate der Global Assessment of Functioning Scale (GAFS) untersucht, welche die Achse V des DSM-III-R bildet. Während alle Parameter

Résumé Le sexe, le statut socio-économique, l'intelligence, le score des symptômes cliniques, et un index de situations psychosociales anormales proposés par un récent projet del'OMS furent étudiés en corrélation avec l'évaluation globale de l'échelle de fonctionnement (Global Assessment of Functioning Scale G.A.F.S.) qui correspond à l'axe V du DSM III R. Tandis que tous les paramètres sont corrélés significativement avec un score GAFS, seul le score symptomatique total n'offre pas d'association significative. Les auteurs ont conclu que le GAFS contribue significativement à l'information clinique en tant que source indépendante.
  相似文献   
6.
BACKGROUND: Previous research found an association between single nucleotide polymorphisms (SNPs) in the promoter region of DRD4 and statistically derived phenotypes generated from attention-deficit/hyperactivity disorder (ADHD) symptoms. We sought to replicate this finding by using the same methodology in an independent sample of ADHD individuals. METHODS: Four SNPs were genotyped in and around DRD4 in 2631 individuals in 642 families. We developed a quantitative phenotype at each SNP by weighting nine inattentive and nine hyperactive-impulsive symptoms. The weights were selected to maximize the heritability at each SNP. Once a quantitative phenotype was generated at each SNP, the screening procedure implemented in PBAT was used to select and test the five SNPs/genetic model combinations with the greatest power to detect an association for DRD4. RESULTS: One of the four SNPs was associated with the quantitative phenotypes generated from the ADHD symptoms (corrected p-values = .02). A rank ordering of the correlation between each of the ADHD symptoms and the quantitative phenotype suggested that hyperactive-impulsive symptoms were more strongly correlated with the phenotype; however, including inattentive symptoms was necessary to achieve a significant result. CONCLUSIONS: This study partially replicated a previous finding by identifying an association between rs7124601 and a quantitative trait generated from ADHD symptoms. The rs7124601 is in linkage disequilibrium (LD) with the SNPs identified previously. In contrast to the previous study, this finding suggests that both hyperactive-impulsive and inattentive symptoms are important in the association.  相似文献   
7.
Studies by comparative genome hybridization have suggested that 5p amplification is related to tumor progression in urinary bladder cancer. In this study seven genes (TAS2R, ADCY2, DNAH5, CTNND2, TRIO, ANKH, and MYO10) located to 5p15.31-5p15.1 were analyzed by fluorescence in situ hybridization using a tissue microarray containing samples from tumors and cell lines with known 5p amplification by comparative genome hybridization. Amplification frequency was highest for TRIO, which maps to 5p15.2 and encodes a protein with a putative role in cell-cycle regulation. To further investigate the role of TRIO amplification in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for fluorescence in situ hybridization analysis. TRIO amplification was strongly associated with invasive tumor phenotype, high tumor grade, and rapid tumor cell proliferation (Ki67 LI) (P < 0.0001 each). Only 7 of 456 pTaG1/G2 tumors (1.5%) but 62 of 485 pT1-4 carcinomas (12.8%) had TRIO amplification. TRIO amplification was not associated with poor prognosis. Using a frozen bladder tumor tissue microarray RNA in situ hybridization confirmed that TRIO is up-regulated in amplified tumors. It is concluded that TRIO up-regulation through amplification has a potential role in bladder cancer progression.  相似文献   
8.
In the Australian echidna Tachyglossus aculeatus, a close relative of the extinct ancestors of higher mammals, the lymphoid organs were investigated by means of autoradiographic studies after the injection of [3H]thymidine and 125I-labelled flagellar antigen of Salmonella adelaide. The histology of organs from echidnas injected with colloidal carbon was studied in parallel. The results lead to the conclusion that each lymph nodule in the echidna represents a single lymphoid follicle comparable to a cortical follicle in lymph nodes of higher mammals. Studies on lymph nodules of echidnas injected with [3H]thymidine revealed the presence of highly active germinal centres, usually one per nodule. Antigen became localized first around the entire nodule; later on it was found within the germinal centre or in its peripheral parts. Often a germinal centre was eccentrically located, in which case the labelled antigen formed the typical germinal centre cap known to be characteristic of secondary follicles in the rat lymph node. A significant uptake of antigen was also seen in the appendix, the Peyer's patches of the gut and in the Hassall's corpuscles of the thymus.

Our findings for the echidna lymph nodule are discussed with respect to their possible significance in the evolutionary development of the multi-follicular lymph node of higher mammals.

  相似文献   
9.
10.
BACKGROUND AND PURPOSE: Based on neuroprotective efficacy in animal models, we evaluated the N-methyl D-aspartate antagonist Selfotel in patients with ischemic stroke, after doses up to 1.5 mg/kg were shown to be safe in phase 1 and phase 2a studies. METHODS: Two pivotal phase 3 ischemic stroke trials tested the hypothesis, by double-blind, randomized, placebo-controlled parallel design, that a single intravenous 1.5 mg/kg dose of Selfotel, administered within 6 hours of stroke onset, would improve functional outcome at 90 days, defined as the proportion of patients achieving a Barthel Index score of >/=60. The trials were performed in patients aged 40 to 85 years with acute ischemic hemispheric stroke and a motor deficit. RESULTS: The 2 trials were suspended on advice of the independent Data Safety Monitoring Board because of an imbalance in mortality after a total enrollment of 567 patients. The groups were well matched for initial stroke severity and time from stroke onset to therapy. There was no difference in the 90-day mortality rate, with 62 deaths (22%) in the Selfotel group and 49 (17%) in the placebo-treated group (RR=1.3; 95% CI 0.92 to 1.83; P=0.15). However, early mortality was higher in the Selfotel-treated patients (day 30: 54 of 280 versus 37 of 286; P=0.05). In patients with severe stroke, mortality imbalance was significant throughout the trial (P=0.05). CONCLUSIONS: Selfotel was not an effective treatment for acute ischemic stroke. Furthermore, a trend toward increased mortality, particularly within the first 30 days and in patients with severe stroke, suggests that the drug might have a neurotoxic effect in brain ischemia.  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