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   857篇
  免费   167篇
  国内免费   69篇
耳鼻咽喉   3篇
儿科学   31篇
妇产科学   17篇
基础医学   96篇
口腔科学   6篇
临床医学   127篇
内科学   179篇
皮肤病学   3篇
神经病学   59篇
特种医学   75篇
外科学   144篇
综合类   126篇
预防医学   105篇
眼科学   6篇
药学   77篇
肿瘤学   39篇
  2022年   7篇
  2021年   14篇
  2020年   8篇
  2019年   18篇
  2018年   22篇
  2017年   11篇
  2016年   7篇
  2015年   14篇
  2014年   21篇
  2013年   33篇
  2012年   38篇
  2011年   26篇
  2010年   19篇
  2009年   27篇
  2008年   33篇
  2007年   82篇
  2006年   35篇
  2005年   36篇
  2004年   38篇
  2003年   38篇
  2002年   47篇
  2001年   44篇
  2000年   74篇
  1999年   30篇
  1998年   26篇
  1997年   23篇
  1996年   25篇
  1995年   26篇
  1994年   10篇
  1993年   15篇
  1992年   29篇
  1991年   25篇
  1990年   19篇
  1989年   24篇
  1988年   20篇
  1987年   11篇
  1986年   17篇
  1985年   8篇
  1984年   9篇
  1983年   8篇
  1980年   5篇
  1979年   5篇
  1978年   4篇
  1977年   6篇
  1976年   4篇
  1974年   6篇
  1973年   4篇
  1972年   5篇
  1971年   5篇
  1966年   4篇
排序方式: 共有1093条查询结果,搜索用时 46 毫秒
991.
Respiratory syncytial virus (RSV) is an important cause of morbidity in children worldwide, although data from equatorial regions are limited. We analysed climatic, spatial, and temporal data for children presenting to hospitals in Lombok island, Indonesia with clinical pneumonia. During the study period, 2878 children presented and 741 RSV cases were identified. In multivariate analysis with an 8-day lag, occurrence of rain was associated with 64% higher incidence of RSV disease [incidence rate ratio (IRR) 1.64, 95% confidence interval (CI) 1.13-2.38]. A 1% rise in mean relative humidity and 1 degree C increase in mean air temperature was associated with a 6% (IRR 1.06, 95% CI 1.03-1.10) and 44% (IRR 1.44, 95% CI 1.24-1.66) increase in RSV cases, respectively. Four statistically significant local clusters of RSV pneumonia were identified within the annual island-wide epidemics. This study demonstrates statistical association of monsoon-associated weather in equatorial Indonesia with RSV. Moreover, within the island-wide epidemics, localized RSV outbreaks suggest local factors influence RSV disease.  相似文献   
992.
993.
994.
BACKGROUND: The purpose of this multicentre, multinational trial was to study whether rLH supplementation to recombinant FSH (rFSH) during the late follicular phase increased pregnancy rates. METHODS: After down-regulation with nafarelin, 526 women were randomized on Day 1 of stimulation to use either rFSH (Gonal-F) alone (n = 261) or to continue after Day 6 of stimulation with both rFSH (Gonal-F) and rLH (Luveris) (n = 265) from Day 6. The starting dose of rFSH was 150-225 IU/day according to age below or above 35 years. RESULTS: Ongoing pregnancy rate at week 10-12 was 28.7% after rFSH alone and 27.2% after rFSH + rLH. This showed no evidence of a difference. Administration of rLH significantly (P< 0.001) increased serum LH. Ongoing pregnancy rates in patients with low LH levels (<33 percentile) on Days 1 and 6 of stimulation showed no difference between the group treated with rFSH only (23.9% low Day 1 LH; 22.1% low Day 6 LH) versus rFSH + rLH (25.0% low Day 1 LH; 28.9% low Day 6 LH). CONCLUSIONS: Supplementing rFSH with daily doses of 75-150 IU of rLH during the second half of the follicular phase showed no evidence of increasing the ongoing pregnancy rates in the general population. (ClinicalTrials.gov, trial number: KF02-035/03).  相似文献   
995.
996.
Hemolytic uremic syndrome (HUS) is characterized by the triad of thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. The non-Shiga toxin-associated HUS (atypical HUS [aHUS]) has been shown to be a disease of complement dysregulation. Mutations in the plasma complement regulators factor H and factor I and the widely expressed membrane cofactor protein (MCP; CD46) have been described recently. This study looked for MCP mutations in a panel of 120 patients with aHUS. In this cohort, approximately 10% of patients with aHUS (11 patients; nine pedigrees) have mutations in MCP. The onset typically was in early childhood. Unlike patients with factor I or factor H mutations, most of the patients do not develop end-stage renal failure after aHUS. The majority of patients have a mutation that causes reduced MCP surface expression. A small proportion expressed normal levels of a dysfunctional protein. As in other studies, incomplete penetrance is shown, suggesting that MCP is a predisposing factor rather than a direct causal factor. The low level of recurrence of aHUS in transplantation in patients with MCP mutations is confirmed, and the first MCP null individuals are described. This study confirms the association between MCP deficiency and aHUS and further establishes that a deficiency in complement regulation, specifically cofactor activity, predisposes to severe thrombotic microangiopathy in the renal vasculature.  相似文献   
997.
OBJECTIVE: The aim of this study was to assess the relationship between receipt of routine childhood immunizations and infant mortality before 6 months of age. METHODS: This was an observational study of 10,274 infants, in a randomized trial of vitamin A supplementation, who received the study dose and survived to at least 1 week of age. The primary outcome was mortality before 6 months of age, analysed in Cox regression models as a function of vaccine receipt and gender. RESULTS: Receipt of Bacille Calmette Guerin (BCG) or diphtheria, tetanus, polio (DTP) vaccine was associated with significant reductions of one-half to two-thirds of mortality hazards; among girls, those who received both BCG and DTP experienced higher mortality than those who received only one of the two vaccines (hazards ratio 2.4; 95% confidence interval 1.2-5.0). CONCLUSION: The reduced mortality rate associated with receipt of BCG or DTP may be due to both biological and selection factors; the analyses regarding the combined effect of these vaccines and gender need to be replicated in other settings.  相似文献   
998.
OBJECTIVE: Panic disorder (PD) has been linked to perturbed processing of threats. This study tested the hypotheses that offspring of parents with PD and offspring with anxiety disorders display relatively greater sensitivity and attention allocation to fear provocation. METHOD: Offspring of adults with PD, major depressive disorder (MDD), or no disorder (ages 9-19) viewed computer-presented face photographs depicting angry, fearful, and happy faces. Offspring rated (1) subjectively experienced fear level, (2) how hostile the face appeared, and (3) nose width. Attention allocation was indexed by latency to perform ratings. RESULTS: Compared with offspring of parents without PD (n = 79), offspring of PD parents (n = 65) reported significantly more fear and had slower reaction times to rate fear, controlling for ongoing anxiety disorder in the offspring. Offspring with an anxiety disorder (n = 65) reported significantly more fear than offspring without an anxiety disorder but not when parental PD was controlled. Social phobia but no other anxiety disorder in offspring was associated with slower reaction times for fear ratings (but not greater fear ratings). Parental PD and offspring social phobia independently predicted slower reaction time. CONCLUSIONS: Results support an association between parental PD and offspring responses to fear provocation. Social phobia in children may have a specific relationship to allocation of attention to subjective anxiety during face viewing.  相似文献   
999.
BACKGROUND: Charge capture plays an important role in every surgical practice. We have developed and merged a custom mobile database (DB) system with our trauma registry (TRACS), to better understand our billing methods, revenue generators, and areas for improved revenue capture. METHODS: The mobile database runs on handheld devices using the Windows Compact Edition platform. The front end was written in C# and the back end is SQL. The mobile database operates as a thick client; it includes active and inactive patient lists, billing screens, hot pick lists, and Current Procedural Terminology and International Classification of Diseases, Ninth Revision code sets. Microsoft Information Internet Server provides secure data transaction services between the back ends stored on each device. Traditional, hand written billing information for three of five adult trauma surgeons was averaged over a 5-month period. Electronic billing information was then collected over a 3-month period using handheld devices and the subject software application. One surgeon used the software for all 3 months, and two surgeons used it for the latter 2 months of the electronic data collection period. This electronic billing information was combined with TRACS data to determine the clinical characteristics of the trauma patients who were and were not captured using the mobile database. RESULTS: Total charges increased by 135%, 148%, and 228% for each of the three trauma surgeons who used the mobile DB application. The majority of additional charges were for evaluation and management services. Patients who were captured and billed at the point of care using the mobile DB had higher Injury Severity Scores, were more likely to undergo an operative procedure, and had longer lengths of stay compared with those who were not captured. CONCLUSION: Total charges more than doubled using a mobile database to bill at the point of care. A subsequent comparison of TRACS data with billing information revealed a large amount of uncaptured patient revenue. Greater familiarity and broader use of mobile database technology holds the potential for even greater revenue capture.  相似文献   
1000.
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