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   4058篇
  免费   372篇
  国内免费   75篇
耳鼻咽喉   11篇
儿科学   134篇
妇产科学   61篇
基础医学   323篇
口腔科学   581篇
临床医学   312篇
内科学   887篇
皮肤病学   80篇
神经病学   238篇
特种医学   92篇
外国民族医学   2篇
外科学   391篇
综合类   339篇
预防医学   138篇
眼科学   29篇
药学   231篇
  3篇
中国医学   127篇
肿瘤学   526篇
  2024年   10篇
  2023年   131篇
  2022年   191篇
  2021年   250篇
  2020年   249篇
  2019年   248篇
  2018年   245篇
  2017年   161篇
  2016年   188篇
  2015年   136篇
  2014年   255篇
  2013年   279篇
  2012年   174篇
  2011年   205篇
  2010年   136篇
  2009年   172篇
  2008年   140篇
  2007年   136篇
  2006年   122篇
  2005年   116篇
  2004年   102篇
  2003年   92篇
  2002年   82篇
  2001年   64篇
  2000年   48篇
  1999年   54篇
  1998年   47篇
  1997年   51篇
  1996年   25篇
  1995年   33篇
  1994年   44篇
  1993年   20篇
  1992年   28篇
  1991年   31篇
  1990年   12篇
  1989年   19篇
  1988年   20篇
  1987年   22篇
  1986年   11篇
  1985年   34篇
  1984年   19篇
  1983年   19篇
  1982年   19篇
  1981年   25篇
  1980年   8篇
  1979年   10篇
  1978年   5篇
  1977年   3篇
  1976年   5篇
  1975年   5篇
排序方式: 共有4505条查询结果,搜索用时 312 毫秒
91.
92.
AIMS: To compare representative general population and treated samples on their reasons for drinking less and whether particular reasons were related to sustained remission from problem drinking for either group. PARTICIPANTS AND DESIGN: A total of 659 problem drinking adults in a Northern California county identified through a probability survey in the general population (n = 239) and a survey of consecutive admissions to public and private alcohol and drug programs (n = 420), who reported drinking less at the one-year follow-up and provided reasons for reducing their drinking, were assessed 1-, 3-, and 5-years post-baseline regarding their problem drinking status. MEASUREMENTS: Logistic regression models were used to predict sustained remission from problem drinking. RESULTS: While the treated sample endorsed a majority of reasons in significantly higher proportions than the general population sample, the same three reasons were significant for both groups in predicting sustained remission from problem drinking: hitting rock bottom, experiencing a traumatic event and undergoing a spiritual awakening. Interventions by medical personnel and family members were either non-significant predictors or significantly negatively related to sustained improvement for both general population and treated problem drinkers. CONCLUSIONS: General population and treatment samples have similar reasons for cutting down as they relate to sustained remission from problem drinking.  相似文献   
93.
94.

Background

Congenital heart surgery has improved the survival of patients with even the most complex defects, but the long-term survival after these procedures has not been fully described.

Objectives

The purpose of this study was to evaluate the long-term survival of patients (age <21 years) who were operated on for congenital heart defects (CHDs).

Methods

This study used the Pediatric Cardiac Care Consortium data, a U.S.-based, multicenter registry of pediatric cardiac surgery. Survival analysis included 35,998 patients who survived their first congenital heart surgery at <21 years of age and had adequate identifiers for linkage with the National Death Index through 2014. Survival was compared to that in the general population using standardized mortality ratios (SMRs).

Results

After a median follow-up of 18 years (645,806 person-years), 3,191 deaths occurred with an overall SMR of 8.3 (95% confidence interval [CI]: 8.0 to 8.7). The 15-year SMR decreased from 12.7 (95% CI: 11.9 to 13.6) in the early era (1982 to 1992) to 10.0 (95% CI: 9.3 to 10.8) in the late era (1998 to 2003). The SMR remained elevated even for mild forms of CHD such as patent ductus arteriosus (SMR 4.5) and atrial septal defects (SMR 4.9). The largest decreases in SMR occurred for patients with transposition of great arteries (early: 11.0 vs. late: 3.8; p < 0.05), complete atrioventricular canal (31.3 vs. 15.3; p < 0.05), and single ventricle (53.7 vs. 31.3; p < 0.05).

Conclusions

In this large U.S. cohort, long-term mortality after congenital heart surgery was elevated across all forms of CHD. Survival has improved over time, particularly for severe defects with significant changes in their management strategy, but still lags behind the general population.  相似文献   
95.
Background:Several randomized controlled trials (RCTs) have evaluated the efficacy of complete vs culprit-only revascularization for treatment of ST-segment elevation myocardial infarction (STEMI) with multivessel disease. However, the efficacy of complete revascularization vs culprit-only revascularization in some STEMI patient subgroups remains unclear.Methods:We searched PubMed and Embase for related RCTs from the start date of databases to January 3, 2020. The endpoint assessed in this meta-analysis was major adverse cardiac events (MACE). Random-effects meta-analysis was conducted stratified by each of the 5 factors of interest (i.e., sex, age, history of diabetes, ECG infarct location, and the number of arteries with stenosis) to estimate pooled hazard ratio and 95% confidence interval. Random-effects meta-regression was conducted to assess subgroup differences. We examined publication bias by drawing funnel plots and performing Egger test. This meta-analysis is reported according to the PRISMA statement.Results:Six RCTs were included for pooled analysis. Compared with culprit-only revascularization, complete revascularization significantly reduced the risk of MACE (hazard ratio 0.48, 95% confidence interval 0.42–0.55; I2 = 0%; P for relative effect < .001). This significant reduction in the risk of MACE exhibited by complete revascularization was observed in most of the subgroups of interest. All of the subgroup effects based on the 5 factors of interest were not statistically significant (Psubgroup ranged from 0.198 to 0.556). Publication bias was not suggested by funnel plots and Egger test.Conclusions:Compared with culprit-only revascularization, complete revascularization significantly reduces the MACE risk in patients with STEMI and multivessel disease, which is independent of sex, age, history of diabetes, ECG infarct location, and the number of arteries with stenosis.  相似文献   
96.

Background:

Magnetic resonance imaging studies have provided evidence of structural modifications in cortical-limbic regions in major depressive disorder. To date, however, few studies have tracked structural changes in patients during treatment. This prospective, longitudinal imaging study investigated associations between brain structure and clinical responsiveness in a sample of patients with treatment-resistant major depressive disorder during an approximate 1-year follow-up period.

Methods:

FreeSurfer software was used to extract volume or cortical thickness values from 6 regions of interest (hippocampus, rostral middle frontal gyrus, orbitofrontal cortex, rostral and caudal anterior cingulate cortices, and inferior temporal gyrus) in patients (n = 26) and matched healthy controls (n = 28). Regions of interest were selected based on previous evidence of potential associations between morphometric characteristics in these regions and treatment response or remission. Analyses were conducted to compare volume and cortical thickness in patients and controls at baseline imaging, determine whether patients’ brain structure at treatment initiation was associated with response over follow-up, and compare longitudinal changes in volume and cortical thickness in patients who achieved sustained 6-month remission (Montgomery-Åsberg Depression Rating Scale Score ≤12) with nonremitters.

Results:

Patients and controls showed no structural differences at baseline. Among patients, thicker right caudal anterior cingulate cortex at baseline was associated with greater symptom improvement over follow-up. Remitters and nonremitters showed subtle changes in volume and thickness over time in opposing directions, with increased hippocampal volume and cortical thickness in the rostral middle frontal gyrus, orbitofrontal cortex, and inferior temporal gyrus in remitters, and decreased volume or thickness in these regions in nonremitters.

Conclusions:

The results suggest that longitudinal structural trajectories may differ in major depressive disorder patients according to their clinical response to treatment.  相似文献   
97.
Introduction:Chimeric antigen receptor T (CAR-T) cells targeting B-cell maturation antigen (BCMA) have been used in the treatment of relapsed and refractory multiple myeloma (RRMM). The response rate and the depth of responses induced by anti-BCMA CAR-T cells are impressive. However, despite this, remissions are not sustained, and the majority of patients eventually relapse.Patient concerns:Two patients with multiple myeloma (MM) were selected to enroll in a phase I study involving anti-BCMA CAR-T cells (ChiCTR-OPC-16009113) because they did not have the good effect after traditional treatment. One is a 48-year-old male patient who received a diagnosis of IgG lambda MM in June 2015, he has received 4 cycles of cyclophosphamide, bortezomib, and dexamethasone (CyBorD) and obtained a complete response (CR). Approximately 11 months later, the disease progressed. Subsequent treatment included regimens incorporating liposomal doxorubicin, bortezomib, and dexamethasone (3 cycles); the response was poor, and the disease kept progressing. Another 65-year-old female patient received a diagnosis of IgG lambda MM in September 2016, she has received induction therapy with 1 cycle of bortezomib and dexamethasone (VD) and 4 cycles of lenalidomide and dexamethasone, the response was poor.Diagnosis:Both patients were diagnosed with RRMM according to the International Myeloma Working Group criteria.Interventions:Both patients received infusions of anti-BCMA CAR-T cells following an induction chemotherapy regimen of cyclophosphamide and fludarabine.Outcomes:Both of them achieved a stringent CR at the 30th day with minimal residual disease-negative bone marrow by flow cytometry and serum monoclonal protein was undetectable at 4 and 10 months after cell transfusion. The CR has persisted in the 2 patients for >36 months.Conclusions:Our findings demonstrate the anti-BCMA CAR-T cell treatment is a feasible therapeutic option for patients with RRMM. Fewer early lines of treatment may be beneficial to maintain the efficacy of CAR-T cells.Trial registration:ChiCTR-OPC-16009113.  相似文献   
98.
Budesonide is a glucocorticoid characterized by its local action, with a low systemic bioavailability. Since the original trial comparing budesonide with prednisone in 2010, it is recommended as an effective alternative for the treatment of non-severe acute or chronic autoimmune hepatitis. In this document, we review the general pharmacologic properties of glucocorticoids, the available evidence for the use of budesonide as first line option for autoimmune hepatitis as well as the safety profile of the drug.  相似文献   
99.
Complete atrioventricular block (CAVB) is a common complication of ST‐segment elevation myocardial infarction (STEMI). Although STEMI patients complicated with CAVB had a higher mortality in the thrombolytic era, little is known about the impact of CAVB on STEMI patients who underwent primary percutaneous coronary intervention (PCI). The study aimed at evaluating the clinical impact of CAVB on STEMI patients in the primary PCI era. We consecutively enrolled 1295 STEMI patients undergoing primary PCI within 24 hours from onset. Patients were divided into two groups according to the infarct location: anterior STEMI (n = 640) and nonanterior STEMI (n = 655). The outcomes were all‐cause death and major adverse cardiocerebrovascular events (MACCE) with a median follow‐up period of 3.8 (1.7–6.6) years. Eighty‐one patients (6.3%) developed CAVB. The incidence of CAVB was lower in anterior STEMI patients than in nonanterior STEMI (1.7% vs 10.7%, p < .05). Anterior STEMI patients with CAVB had a higher incidence of all‐cause deaths (82% vs 20%, p < .05) and MACCE (82% vs 25%, p < .05) than those without CAVB. Although higher incidence of all‐cause deaths was found more in nonanterior STEMI patients with CAVB compared with those without CAVB (30% vs 18%, p < .05), there was no significant difference in the incidence of MACCE (24% vs 19%). Multivariate analysis showed that CAVB was an independent predictor for all‐cause mortality and MACCE in anterior STEMI patients, but not in nonanterior STEMI. CAVB is rare in anterior STEMI patients, but remains a poor prognostic complication even in the primary PCI era.  相似文献   
100.
Gastrointestinal stromal tumour (GIST) is a rare tumour of the gastrointestinal tract which does not generally originate in the rectum. The authors describe a case of a 70-year-old man who underwent an anterior resection of the rectum for a low-risk GIST. The patient was not given adjuvant chemotherapy with imatinib and is still disease-free 30 mo after surgery. The authors conclude that although rectal GIST is extremely uncommon, it should be included in differential diagnosis when a tumour in the rectum is detected. Biopsy of the tumour is essential, since this makes it possible to reach a sure preoperative diagnosis based on the immunohistological features of the CDl17 and CD34. Although complete surgical resection with negative tumour margins is the principal curative procedure for primary and nonmetastatic tumours, further studies are still needed for the determination of the most effective treatment strategy for patients with rectal GIST.  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