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   2784篇
  免费   185篇
  国内免费   81篇
耳鼻咽喉   55篇
儿科学   104篇
妇产科学   48篇
基础医学   287篇
口腔科学   88篇
临床医学   276篇
内科学   615篇
皮肤病学   248篇
神经病学   142篇
特种医学   320篇
外科学   249篇
综合类   39篇
预防医学   231篇
眼科学   38篇
药学   152篇
中国医学   10篇
肿瘤学   148篇
  2023年   14篇
  2022年   17篇
  2021年   49篇
  2020年   30篇
  2019年   50篇
  2018年   80篇
  2017年   51篇
  2016年   67篇
  2015年   79篇
  2014年   90篇
  2013年   88篇
  2012年   118篇
  2011年   128篇
  2010年   93篇
  2009年   103篇
  2008年   117篇
  2007年   149篇
  2006年   129篇
  2005年   129篇
  2004年   104篇
  2003年   98篇
  2002年   89篇
  2001年   89篇
  2000年   92篇
  1999年   68篇
  1998年   95篇
  1997年   83篇
  1996年   68篇
  1995年   67篇
  1994年   51篇
  1993年   51篇
  1992年   47篇
  1991年   33篇
  1990年   36篇
  1989年   53篇
  1988年   52篇
  1987年   34篇
  1986年   30篇
  1985年   33篇
  1984年   23篇
  1983年   19篇
  1982年   22篇
  1981年   13篇
  1980年   15篇
  1979年   15篇
  1978年   9篇
  1977年   21篇
  1976年   14篇
  1975年   17篇
  1972年   5篇
排序方式: 共有3050条查询结果,搜索用时 15 毫秒
91.
92.
ObjectiveLeukotrienes (LT) play a role in inflammation, cardiovascular diseases, and cancer. Although some studies suggest that there are genes that determine variability of some LT-related phenotypes, the genetic influence on these phenotypes has not been evaluated.MethodsThe relative contributions of genetic and environmental influences to the 5-lipoxygenase pathway-related phenotypes (5-Lipoxygenase, five lipoxygenase activating protein (FLAP), LTA4-hydrolase and LTC4-synthase expression, and LTB4-plasma concentration and LTB4 production by stimulated whole blood) were assessed in a sample of 934 individuals in 35 extended families. Our design is based on extended families recruited through a probands with idiopathic thrombophilia. This strategy allows us the analysis of the effects of measured covariates (such as sex, age and smoking), genes, and environmental variables shared by members of a household.ResultsAll of these phenotypes showed significant genetic contributions, with heritabilities ranging from 0.33 to 0.51 for enzyme expression and from 0.25 to 0.50 for LTB4 production of the residual phenotypic variance. Significant phenotypic and genetic correlation among the LT-related traits was found. More importantly, FLAP and LTA4-hydrolase expression exhibit significant genetic correlations with arterial thrombosis, indicating that some of the genes that influence quantitative variation in these phenotypes also influence the risk of thrombosis.ConclusionThis is the first study that quantifies the genetic component of 5-Lipoxygenase pathway phenotypes. The high heritability of these traits and the significant genetic correlations between arterial thrombosis and some of these phenotypes suggest that the exploitation of correlated quantitative phenotypes will aid the search for susceptibility genes.  相似文献   
93.
94.
Late-onset hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT) has been associated with BK virus (BKV). Antiviral drugs are of limited efficacy and the optimal treatment for HC has not yet been established. Hyperbaric oxygen (HBO) may benefit these patients. We, therefore, retrospectively evaluated the effectiveness of HBO therapy in 16 patients with HC after allogeneic HSCT. All 16 patients had macroscopic hematuria and BKV infection. Patients received 100% oxygen in a hyperbaric chamber at 2.1 atmospheres for 90?min, 5 days per week, with a median 13 treatments (range, 4-84). Fifteen patients (94%) showed complete resolution of hematuria. Median urinary DNA BKV titers declined after HBO (P<0.05). Patients started on HBO earlier after diagnosis of HC responded sooner (P<0.05). HBO was generally well tolerated and proved to be a reliable option for this difficult to manage condition.  相似文献   
95.
96.
A Plasmodium falciparum circumsporozoite protein (CSP)-based recombinant fusion vaccine is the first malaria vaccine to reach phase III clinical trials. Resistance to infection correlated with the production of antibodies to the immunodominant central repeat region of the CSP. In contrast to P. falciparum, vaccine development against the CSP of Plasmodium vivax malaria is far behind. Based on this gap in our knowledge, we generated a recombinant chimeric protein containing the immunodominant central repeat regions of the P. vivax CSP fused to Salmonella enterica serovar Typhimurium-derived flagellin (FliC) to activate the innate immune system. The recombinant proteins that were generated contained repeat regions derived from each of the 3 different allelic variants of the P. vivax CSP or a fusion of regions derived from each of the 3 allelic forms. Mice were subcutaneously immunized with the fusion proteins alone or in combination with the Toll-like receptor 3 (TLR-3) agonist poly(I·C), and the anti-CSP serum IgG response was measured. Immunization with a mixture of the 3 recombinant proteins, each containing immunodominant epitopes derived from a single allelic variant, rather than a single recombinant protein carrying a fusion of regions derived from each of 3 allelic forms elicited a stronger immune response. This response was independent of TLR-4 but required TLR-5/MyD88 activation. Antibody titers significantly increased when poly(I·C) was used as an adjuvant with a mixture of the 3 recombinant proteins. These recombinant fusion proteins are novel candidates for the development of an effective malaria vaccine against P. vivax.  相似文献   
97.
ObjectiveTo analyze the impact of reperfusion by either primary percutaneous coronary intervention (PPCI) or fibrinolysis, and mortality rates of a pre-hospital fast-track network for treating patients with ST-elevation myocardial infarction (STEMI).Methods and ResultsA pre-hospital network for STEMI patients, designated the Green Lane for Acute Myocardial Infarction (GL-AMI), has been implemented in the southern region of Portugal – the Algarve Project. We performed an observational study based on a prospective registry of 1338 patients admitted to Faro Hospital between 2004 and 2009, classified in two groups according to the method of admission: emergency department group (EDG) and GL-AMI group (GLG). More patients from GLG were reperfused (p < 0.0001). PPCI was the preferred method of reperfusion, 73.1% in GLG and 45.3% in EDG. Time delays were significantly shorter in GLG, except for pre-hospital delay: pre-hospital delay (p = 0.11); door-to-needle (p < 0.0001); door-to-balloon (p < 0.0001); and delay between symptoms and reperfusion (p < 0.0001). In-hospital mortality (4.3% vs 9.2%, p = 0.0007) and 6-month mortality (6.3% vs 13.8%, p < 0.0001) were significantly lower in GLG.ConclusionsThe Algarve Project significantly reduced the time delay between onset of symptoms and reperfusion, significantly increased the rate of reperfusion, and significantly reduced in-hospital and six-month mortality.  相似文献   
98.

Background

For rectal cancer, it is unknown how use of radiation, treatment cost, and survival differ based on hospital teaching designation.

Methods

Private insurance claims data linked with the Pennsylvania Cancer Registry were used to identify rectal cancer patients undergoing surgery from 2004 to 2006. Patients with missing data of interest were excluded. Hospitals were characterized as follows: large (≥200 beds) versus small size (<200 beds), teaching versus nonteaching, and urban versus rural. Logistic regression was used to model the use of neoadjuvant radiotherapy, and Cox proportional hazards models were used to compare cancer-specific survival between hospital types.

Results

A total of 432 patients were analyzed. There was no difference in the distribution of cancer stages among the various hospital types (all p > 0.20). Teaching hospitals were associated with significantly higher utilization of neoadjuvant radiotherapy for stage II and III cancers compared with nonteaching facilities (57 vs. 28 %; p < 0.0001). On multivariate analysis, teaching status was the only hospital designation associated with use of neoadjuvant radiation (p < 0.001); hospital size and rural/urban designation were not significant. Nonteaching hospitals were more likely to use adjuvant radiotherapy for stage II and III disease (13 vs. 30 %; p < 0.01). Teaching hospitals had lower odds of death from rectal cancer when evaluating all stages [hazard ratio (HR) = 0.35; p < 0.0001] with similar costs of inpatient treatment (teaching: US $30,769 versus nonteaching: US $26,892; p = 0.22).

Conclusions

Teaching designation was associated with higher incidence of neoadjuvant radiotherapy for stage II and III disease, with improved cancer-specific survival compared with nonteaching hospitals, and with similar treatment costs.  相似文献   
99.
100.
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