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   2391篇
  免费   232篇
  国内免费   17篇
耳鼻咽喉   9篇
儿科学   153篇
妇产科学   36篇
基础医学   352篇
口腔科学   7篇
临床医学   343篇
内科学   601篇
皮肤病学   30篇
神经病学   160篇
特种医学   38篇
外科学   170篇
综合类   82篇
一般理论   1篇
预防医学   477篇
眼科学   27篇
药学   95篇
中国医学   8篇
肿瘤学   51篇
  2024年   4篇
  2023年   39篇
  2022年   29篇
  2021年   85篇
  2020年   54篇
  2019年   11篇
  2018年   50篇
  2017年   42篇
  2016年   48篇
  2015年   66篇
  2014年   46篇
  2013年   98篇
  2012年   228篇
  2011年   229篇
  2010年   94篇
  2009年   82篇
  2008年   180篇
  2007年   214篇
  2006年   177篇
  2005年   211篇
  2004年   193篇
  2003年   174篇
  2002年   121篇
  2001年   81篇
  2000年   17篇
  1999年   6篇
  1998年   12篇
  1997年   7篇
  1996年   8篇
  1995年   3篇
  1994年   6篇
  1993年   5篇
  1992年   2篇
  1991年   1篇
  1988年   1篇
  1987年   1篇
  1986年   4篇
  1985年   1篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1958年   1篇
排序方式: 共有2640条查询结果,搜索用时 15 毫秒
1.
2005年6月四川省报告狂犬病10例,均死亡。与上月及去年同期比,报告发病、死亡分别上升43%、400%。报告发病、死亡病例主要分布于自贡市(3例)、乐山市(2例)、眉山市(2例)、达州市(2例)、成都市(1例)。截止2005年6月30日,全省已累计报告狂犬病发病24例,均死亡。2~70岁各年龄段均有发病,主要集中在50~60岁年龄组,占50%。男女性别比3:1。职业以农民为主,约占58%。  相似文献   
2.
内蒙古:2006年5月报告病例1215例,比上月上升42.6%,比去年同期上升2.88%,病例主要集中在锡林郭勒盟(358例)、乌兰察布市(347例)、呼伦贝尔市(234例)、赤峰市(94例)及兴安盟和通辽市(各83例)。职业以农民和牧民为主,分别占61.07%和23.78%。  相似文献   
3.
We investigated the natural history of atopic dermatitis (AD) in a population-based birth cohort and assessed whether children at risk of visible eczema at 5 years of age can be identified from total immunoglobulin E (IgE) levels measured at 8, 12 and 18 months. AD data collected included a whole body examination for visible eczema at 49 months (4 years) and 61 months (5 years) of age and parent completed questionnaire data throughout their early lives. Children were divided into four groups based on their natural history of early AD: persistent (AD at 1, 6, 18, 30 and 42 months, n  = 34), intermittent early onset (before 18  months of age, n  = 495), intermittent late onset (18–42 months of age, n  = 273) and unaffected ( n  = 429). Visible eczema at 5 years of age was present in 12.2% (117/957) (95% confidence interval [CI] 10.1–14.3%) of the children. Levels of total IgE at 8, 12 and 18 months of age were associated with early onset of AD, but not with AD of later onset. For all four natural history groups, the geometric mean total IgE at 12 months was higher in those who subsequently had visible eczema than those who did not. However, the degree of overlap was such that total IgE at 12 months of age was a poor predictor of eczema at age five. A cutoff point of 78 kU/l had the highest positive predictive value for visible eczema at 5 years of age of 28.6%, with a sensitivity of 12% and specificity of 95%.  相似文献   
4.
Background Poor co‐ordination of services can have severe consequences for disadvantaged children with complex needs. Since 2003 national and local governments in England embarked on sweeping reforms aimed at improving and integrating local health, education and social services for children. These were to be organized locally by children's trusts and piloted by 35 children's trust pathfinders. Methods This study described and compared the experience of integrating children's services in all 35 children's trust pathfinders, covering 20% of children in England. It had a prospective mixed‐methods design. Over 3 years we interviewed 147 managers and professionals working in the children's trusts, including 172 semi‐structured interviews, carried out two questionnaire surveys of the 35 children's trusts and analysed official documents. Results In most areas different agencies jointly commissioned children's services, especially for mental health, disabilities and multi‐purpose children's centres, and increasingly pooled finances. Provision of multi‐agency and multi‐professional services was increasing. Professionals generally supported these changes but found them stressful. All children's trusts appointed directors of children's services and established boards representing multiple agencies. Systems for sharing information about individual children were mostly in place but were still underused. Health services were generally less involved in joint work than were local authorities' education and social care services, with notable exceptions. Areas where local authorities and health authorities shared geographical boundaries made most progress. Some children's trusts made few changes beyond their statutory obligations. Conclusion Children's trusts enabled major changes to services in areas where local actors and organizations were motivated and empowered. In other areas the remit of children's trusts was often too broad and vague to overcome entrenched organizational and professional divisions and interests. Policymakers need to balance facilitation of change in areas with dynamic change agents with methods for ensuring that dormant areas and agencies are not left behind.  相似文献   
5.
政府采购对中国经济的影响   总被引:2,自引:0,他引:2  
崔颖 《中国卫生经济》2003,22(12):16-17
从政府采购制度及其理论依据入手,从公共财政理论和新公共管理理论等方面分析了政府采购制度的利与弊。提出政府应利用行政、法律等手段加强对政府采购制度的宏观管理和监督,并逐步淡出微观管制。在政府采购制度与采购行为中,政府的作用不是取代市场,而是为市场保驾护航,让市场更好地发挥作用。  相似文献   
6.
BACKGROUND: Continence services in the UK have developed at different rates within differing care models, resulting in scattered and inconsistent services. Consequently, questions remain about the most cost-effective method of delivering these services. AIM: To evaluate the impact of a new service led by a continence nurse practitioner compared with existing primary/secondary care provision for people with urinary incontinence and storage symptoms. DESIGN OF STUDY: Randomised controlled trial with a 3- and 6-month follow-up in men and women (n = 3746) aged 40 years and over living in private households (intervention [n = 2958]; control [n = 788]). SETTING: Leicestershire and Rutland, UK. METHOD: The continence nurse practitioner intervention comprised a continence service provided by specially trained nurses delivering evidence-based interventions using predetermined care pathways. They delivered an 8-week primary intervention package that included advice on diet and fluids; bladder training; pelvic floor awareness and lifestyle advice. The standard care arm comprised access to existing primary care including GP and continence advisory services in the area. Outcome measures were recorded at 3 and 6 months post-randomisation. RESULTS: The percentage of individuals who improved (with at least one symptom alleviated) at 3 months was 59% in the intervention group compared with 48% in the standard care group (difference of 11%, 95% CI = 7 to 16; P<0.001) The percentage of people reporting no symptoms or 'cured' was 25% in the intervention group and 15% in the standard care group (difference of 10%, 95% CI = 6 to 13, P = 0.001). At 6 months the difference was maintained. There was a significant difference in impact scores between the two groups at 3 and 6 months. CONCLUSIONS: The continence nurse practitioner-led intervention reduced the symptoms of incontinence, frequency, urgency and nocturia at 3 and 6 months; impact was reduced; and satisfaction with the new service was high.  相似文献   
7.
Acute inflammatory response to endotoxin in mice and humans   总被引:3,自引:0,他引:3  
Endotoxin injection has been widely used to study the acute inflammatory response. In this study, we directly compared the inflammatory responses to endotoxin in mice and humans. Escherichia coli type O113 endotoxin was prepared under identical conditions, verified to be of equal biological potency, and used for both mice and humans. The dose of endotoxin needed to induce an interleukin-6 (IL-6) concentration in plasma of approximately 1,000 pg/ml 2 h after injection was 2 ng/kg of body weight in humans and 500 ng/kg in mice. Healthy adult volunteers were injected intravenously with endotoxin, and male C57BL/6 mice (n=4 to 12) were injected intraperitoneally with endotoxin. Physiological, hematological, and cytokine responses were determined. Endotoxin induced a rapid physiological response in humans (fever, tachycardia, and slight hypotension) but not in mice. Both mice and humans exhibited lymphopenia with a nadir at 4 h and recovery by 24 h. The levels of tumor necrosis factor (TNF) and IL-6 in plasma peaked at 2 h and returned to baseline levels by 4 to 6 h. IL-1 receptor antagonist RA and TNF soluble receptor I were upregulated in both mice and humans but were upregulated more strongly in humans. Mice produced greater levels of CXC chemokines, and both mice and humans exhibited peak production at 2 h. These studies demonstrate that although differences exist and a higher endotoxin challenge is necessary in mice, there are several similarities in the inflammatory response to endotoxin in mice and humans.  相似文献   
8.
BACKGROUND: We recently found that paracetamol (acetaminophen) use in late pregnancy was associated with an increased risk of early wheezing in the offspring. OBJECTIVE: To see whether use of paracetamol in late pregnancy is associated with an increased risk of asthma, wheezing and other atopic outcomes in the child at school age. METHODS: In the population-based Avon Longitudinal Study of Parents and Children, we measured associations of paracetamol and aspirin use in late pregnancy (20-32 weeks) with asthma, hayfever, eczema (n = 8511) and wheezing (8381) in the offspring at 69-81 months, and with atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n = 6527) and blood total IgE (n = 5148) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders. RESULTS: Use of paracetamol, but not aspirin, in late pregnancy was positively associated with asthma (odds ratios (ORs), comparing children whose mothers took paracetamol 'sometimes' and 'most days/daily' with those whose mothers never took it, 1.22 (95% confidence interval (CI): 1.06-1.41) and 1.62 (95% CI: 0.86-3.04), respectively; P trend = 0.0037), wheezing (ORs 1.20 (95% CI: 1.02-1.40) and 1.86 (95% CI: 0.98-3.55), respectively; P trend = 0.011), and total IgE (geometric mean ratios 1.14 (95% CI: 1.03-1.26) and 1.52 (95% CI: 0.98-2.38), respectively; P trend = 0.0034), but not hayfever, eczema or skin test positivity. The proportion of asthma attributable to paracetamol use in late pregnancy, assuming a causal relation, was 7%. CONCLUSION: Paracetamol exposure in late gestation may cause asthma, wheezing and elevated IgE in children of school age.  相似文献   
9.
The long intracellular half-life of abacavir (ABC) supports its once-daily use, and this would be expected to simplify treatment if ABC could be given as part of a complete once-daily regimen. A randomized double-blind clinical trial compared the efficacy and safety of 600 mg of ABC administered once daily (n = 384) versus 300 mg of ABC administered twice daily (n = 386) in combination with 300 mg of lamivudine (3TC) and 600 mg of efavirenz (EFV) administered once daily in antiretroviral-naive patients over 48 weeks. The baseline median plasma HIV-1 RNA level was 4.89 log10 copies/mL (44% with viral load >100,000 copies/mL), and the median CD4 cell count was 262 cells/mm. ABC administered once daily was non-inferior to the twice-daily regimen, with 66% and 68% of patients in these respective treatment arms achieving a confirmed plasma HIV-1 RNA level <50 copies/mL (95% confidence interval: -8.4%, 4.9%). The ABC once-daily and twice-daily regimens were similar with respect to infrequency of virologic failure (10% vs. 8%), emergence of resistance mutations, CD4 cell increases from baseline (median, 188 vs. 200 cells/mm), safety profile, and incidence of ABC-related hypersensitivity reactions (9% vs. 7%). ABC administered once daily in combination with 3TC and EFV administered once daily was non-inferior to the ABC twice-daily dosing schedule when combined with 3TC and EFV over 48 weeks.  相似文献   
10.
Although many studies on alternative splicing of specific genes have been reported in the literature, the general mechanism that regulates alternative splicing has not been clearly understood. In this study, we systematically aligned each pair of the 21,076 cDNA sequences of Mus musculus, searched for putative alternative splicing patterns, and constructed a list of potential alternative splicing sites. Two cDNAs are suspected to be alternatively spliced and originating from a common gene if they share most of their region with a high degree of sequence homology, but parts of the sequences are very distinctive or deleted in either cDNA. The list contains the following information: (1) tissue, (2) developmental stage, (3) sequences around splice sites, (4) the length of each gapped region, and (5) other comments. The list is available at http://www.bioinfo.sfc.keio.ac.jp/intron. Our results have predicted a number of unreported alternatively spliced genes, some of which are expressed only in a specific tissue or at a specific developmental stage.  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