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   7851篇
  免费   516篇
  国内免费   7篇
耳鼻咽喉   32篇
儿科学   226篇
妇产科学   154篇
基础医学   966篇
口腔科学   81篇
临床医学   976篇
内科学   1478篇
皮肤病学   58篇
神经病学   792篇
特种医学   197篇
外科学   905篇
综合类   419篇
一般理论   5篇
预防医学   978篇
眼科学   68篇
药学   485篇
中国医学   5篇
肿瘤学   549篇
  2023年   62篇
  2022年   84篇
  2021年   197篇
  2020年   125篇
  2019年   195篇
  2018年   229篇
  2017年   156篇
  2016年   170篇
  2015年   206篇
  2014年   323篇
  2013年   398篇
  2012年   573篇
  2011年   680篇
  2010年   314篇
  2009年   279篇
  2008年   596篇
  2007年   563篇
  2006年   519篇
  2005年   486篇
  2004年   466篇
  2003年   382篇
  2002年   368篇
  2001年   110篇
  2000年   89篇
  1999年   99篇
  1998年   76篇
  1997年   58篇
  1996年   49篇
  1995年   46篇
  1994年   29篇
  1993年   16篇
  1992年   47篇
  1991年   33篇
  1990年   33篇
  1989年   29篇
  1988年   26篇
  1987年   19篇
  1986年   16篇
  1985年   23篇
  1984年   24篇
  1983年   13篇
  1982年   11篇
  1981年   10篇
  1980年   10篇
  1979年   9篇
  1976年   9篇
  1974年   11篇
  1972年   9篇
  1969年   8篇
  1966年   9篇
排序方式: 共有8374条查询结果,搜索用时 31 毫秒
991.
992.
993.

Objective

To determine which work-related injuries are the most frequent and costly.

Design

Secondary analysis of workers' compensation claims data.

Setting

Data were provided by a large, Maryland workers' compensation insurer from 1998 through 2008.

Participants

Not applicable.

Interventions

None.

Main Outcomes Measures

For 45 injury types, the number of claims and compensation amount was calculated for total compensation and for medical and indemnity compensation separately.

Results

Back and knee injuries were the most frequently occurring single injury types, whereas heart attack and occupational disease were the most expensive in terms of mean compensation. When taking into account both the frequency and cost of injury (mean cost × number occurrences), back, knee, and shoulder injuries were the most expensive single injury types.

Conclusions

Successful prevention and management of back, knee, and shoulder injuries could lead to a substantial reduction in the burden associated with work-related injuries.  相似文献   
994.
The symptoms of prion infection can take years or decades to manifest following the initial exposure. Molecular markers of prion disease include accumulation of the misfolded prion protein (PrPSc), which is derived from its cellular precursor (PrPC), as well as downregulation of the PrP-like Shadoo (Sho) glycoprotein. Given the overlapping cellular environments for PrPC and Sho, we inferred that PrPC levels might also be altered as part of a host response during prion infection. Using rodent models, we found that, in addition to changes in PrPC glycosylation and proteolytic processing, net reductions in PrPC occur in a wide range of prion diseases, including sheep scrapie, human Creutzfeldt-Jakob disease, and cervid chronic wasting disease. The reduction in PrPC results in decreased prion replication, as measured by the protein misfolding cyclic amplification technique for generating PrPSc in vitro. While PrPC downregulation is not discernible in animals with unusually short incubation periods and high PrPC expression, slowly evolving prion infections exhibit downregulation of the PrPC substrate required for new PrPSc synthesis and as a receptor for pathogenic signaling. Our data reveal PrPC downregulation as a previously unappreciated element of disease pathogenesis that defines the extensive, presymptomatic period for many prion strains.  相似文献   
995.

Summary

Between 1997?C1998 and 2006?C2007 in Australia, the age-standardised incidence rates of hip fractures declined by 20 and 13?%, in females and males, respectively. Although this may be related to the rollout of public health campaigns and strategies addressing osteoporosis, absolute numbers of hip fractures continued to increase.

Background

Previous reports described an increasing trend in osteoporotic hip fracture incidence in Australia in the 1980s with a stabilisation over the 1990s.

Aim

The aim of this study was to describe national trends in the incidence of osteoporotic hip fracture in Australia between 1997?C1998 and 2006?C2007.

Methods

Data on low-trauma hip fractures in persons aged 50?years and over were obtained from the National Hospital Morbidity Database. Cases where the patient was transferred in from another hospital were excluded. Age-standardised incidence rates were calculated and a linear test for trend applied.

Results

Although the absolute number of hip fracture cases has continued to increase, from 14,769 in 1997?C1998 to 16,412 in 2006?C2007, these numbers are lower than previous predictions based on population ageing. Over the 10-year period, the age-standardised incidence rates in females declined by 20?%, from 370 to 295 per 100,000, while the age-standardised incidence rates in males declined by 13?%, from 200 to 174 per 100,000. Both declines were statistically significant. The sex difference in incidence rates narrowed between 1997?C1998 (females 85?% higher) and 2006?C2007 (females 70?% higher).

Conclusions

The age-standardised incidence of osteoporotic hip fracture in Australia is falling. This may be related to the uptake of bisphosphonates as well as the rollout of public health campaigns and strategies addressing osteoporosis.  相似文献   
996.
997.
998.
Burkholderia cepacia complex (Bcc) pulmonary infections in people living with cystic fibrosis (CF) are difficult to treat because of the extreme intrinsic resistance of most isolates to a broad range of antimicrobials. Fosmidomycin is an antibacterial and antiparasitic agent that disrupts the isoprenoid biosynthesis pathway, a precursor to hopanoid biosynthesis. Hopanoids are involved in membrane stability and contribute to polymyxin resistance in Bcc bacteria. Checkerboard MIC assays determined that although isolates of the Bcc species B. multivorans were highly resistant to treatment with fosmidomycin or colistin (polymyxin E), antimicrobial synergy was observed in certain isolates when the antimicrobials were used in combination. Treatment with fosmidomycin decreased the MIC of colistin for isolates as much as 64-fold to as low as 8 μg/ml, a concentration achievable with colistin inhalation therapy. A liquid chromatography-tandem mass spectrometry technique was developed for the accurate quantitative determination of underivatized hopanoids in total lipid extracts, and bacteriohopanetetrol cyclitol ether (BHT-CE) was found to be the dominant hopanoid made by B. multivorans. The amount of BHT-CE made was significantly reduced upon fosmidomycin treatment of the bacteria. Uptake assays with 1-N-phenylnaphthylamine were used to determine that dual treatment with fosmidomycin and colistin increases membrane permeability, while binding assays with boron-dipyrromethene-conjugated polymyxin B illustrated that the addition of fosmidomycin had no impact on polymyxin binding. This work indicates that pharmacological suppression of membrane hopanoids with fosmidomycin treatment can increase the susceptibility of certain clinical B. multivorans isolates to colistin, an agent currently in use to treat pulmonary infections in CF patients.  相似文献   
999.
The aim of this article is to understand the components of decision regret for women making breast cancer treatment decisions. Patient-centered care models encourage women to become more active in the decision-making process, inadvertently exposing them to the risk of experiencing decision regret. Enhancing the understanding of the concept of decision regret can offer insight into ways to mitigate this phenomenon. The Walker and Avant method was used to analyze this concept. Using PubMed, CINAHL, ERIC, Academic Search Complete, PsychINFO, SocINDEX, Joanna Briggs Institute of EBP Database, and an online dictionary, articles from 2011 to 2021 were analyzed to identify concept uses, attributes, antecedents, and consequences. Decision regret in women making breast cancer healthcare decisions is a negative cognitive-emotional response to a treatment decision that involves counterfactual thinking with three targets of regret: outcome regret, chosen option regret, and process regret. Experiencing decision regret can reduce a woman's quality of life, inflict psychological distress, and impact future decision-making. Unfavorable outcomes, decision uncertainty, and breakdowns in the decision-making process can lead to decision regret. Findings provide information on identifying women experiencing decision regret and illustrate opportunities to address causative factors through patient education and support to promote optimal patient outcomes.  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