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   2775篇
  免费   165篇
  国内免费   20篇
耳鼻咽喉   41篇
儿科学   20篇
妇产科学   20篇
基础医学   313篇
口腔科学   54篇
临床医学   170篇
内科学   731篇
皮肤病学   49篇
神经病学   183篇
特种医学   89篇
外科学   603篇
综合类   4篇
预防医学   103篇
眼科学   19篇
药学   175篇
中国医学   3篇
肿瘤学   383篇
  2024年   4篇
  2023年   31篇
  2022年   55篇
  2021年   85篇
  2020年   56篇
  2019年   85篇
  2018年   102篇
  2017年   64篇
  2016年   83篇
  2015年   109篇
  2014年   113篇
  2013年   127篇
  2012年   195篇
  2011年   230篇
  2010年   143篇
  2009年   125篇
  2008年   179篇
  2007年   184篇
  2006年   174篇
  2005年   166篇
  2004年   155篇
  2003年   121篇
  2002年   124篇
  2001年   17篇
  2000年   16篇
  1999年   27篇
  1998年   29篇
  1997年   21篇
  1996年   10篇
  1995年   10篇
  1994年   12篇
  1993年   8篇
  1992年   10篇
  1991年   11篇
  1990年   4篇
  1989年   9篇
  1988年   11篇
  1987年   8篇
  1986年   10篇
  1985年   4篇
  1984年   4篇
  1983年   3篇
  1981年   3篇
  1979年   4篇
  1978年   2篇
  1977年   2篇
  1971年   2篇
  1970年   4篇
  1969年   2篇
  1966年   1篇
排序方式: 共有2960条查询结果,搜索用时 11 毫秒
71.
We present the youngest patient reported to date with chronic nonspecific multiple ulcers of the small intestine (CNSU) diagnosed by double-balloon endoscopy (DBE). A 3-year-old girl was referred to our department with a 2-year history of iron-deficiency anemia. Failure to thrive and hypoproteinemia were also noted, and stool occult blood tests had been persistently positive. However, the C-reactive protein level and erythrocyte sedimentation rate were not elevated. Esophagogastroduodenoscopy and double-contrast enema revealed no abnormality in the colon and terminal ileum. Retrograde DBE was performed when the patient was 4 years old. Linear ulcerations arranged in an oblique or circular pattern were present at 3 sites between 55 and 65 cm from the ileocecal valve. Microscopic examination showed nonspecific inflammatory changes, and no granuloma was present. Based on the clinical and endoscopic findings, the patient was diagnosed as having CNSU. The youngest previously reported patient with CNSU was 7 years old, whereas our present patient was diagnosed at the age of 4 years. In pediatric cases of obscure gastrointestinal bleeding, it may be necessary to be aware of small bowel disease.  相似文献   
72.

Objective

The aim of this study was to examine the impact of CYP2C19 genotype on clinical outcome in coronary artery disease (CAD) patients with or without diabetes mellitus (DM).

Methods

CYP2C19 polymorphism and DM are associated with increased risk of cardiovascular events during antiplatelet therapy following stent implantation. Platelet reactivity during clopidogrel therapy and CYP2C19 polymorphism were measured in 519 CAD patients (males 70%, age 69 years) treated with stent placement. Patients were divided into two groups; DM (n = 249), and non-DM (n = 270), and clinical events were evaluated according to the carrier state, which included at least one CYP2C19 loss-of-function allele.

Results

The level of platelet reactivity and incidence of cardiovascular events were significantly different between Carriers and non-Carriers of the non-DM (platelet reactivity: 4501 +/− 1668 versus 3691 +/− 1714AUmin, P < 0.01; events, 32/178 versus 2/92, P < 0.01, respectively), however, there was no difference in clinical outcome in the DM group (events, 34/168 versus 14/81, respectively, P = 0.57). Multivariate analysis identified CYP2C19 loss-of-function allele carriage as an independent predictor of cardiovascular events in non-DM, but not in DM (non-DM, HR 7.180, 95% CI, 1.701 to 30.298, P = 0.007; DM, HR 1.374, 95% CI, 0.394 to 4.792, P = 0.618).

Conclusion

The impact of CYP2C19 polymorphism on clinical outcome seems to be more significant in non-DM compared with DM in patients with coronary stents.  相似文献   
73.

Introduction

There is some controversy regarding the effect of CYP2C19 polymorphism on clinical outcome in patients with dual antiplatelet therapy. Chronic kidney disease (CKD) is associated with increased risk of cardiovascular event, but the association between the possession of CYP2C19 loss-of-function (LOF) alleles and clinical outcome according to the presence of CKD is poorly understood. The aim of this study was to investigate whether CKD status modifies the association of CYP2C19 polymorphism in predicting outcomes in a prospective cohort study.

Material and Methods

We enrolled 331 patients following coronary stent implantation. Patients were divided into two groups: CKD (n = 154) and non-CKD (n = 177). Platelet reactivity and CYP2C19 polymorphism were examined. The subjects were further divided into two groups according to the possession of CYP2C19 LOF alleles: carriers and non-carriers. Patients were followed up and clinical events were evaluated according to CKD and carrier status.

Results

The proportion of high platelet reactivity was significantly higher in carriers than in non-carriers in both CKD (42.4% versus 21.7%; P = 0.016) and non-CKD groups (34.3% versus 3.7%; P < 0.001). In the non-CKD group alone, the incidence of cardiovascular events was significantly higher in carriers than in non-carriers (13.7% versus 1.7%; P = 0.013). Kaplan-Meier analysis demonstrated a significantly higher probability of cardiovascular events in carriers than in non-carriers in the non-CKD group (log-rank test: P = 0.013) and there was no significant difference in the CKD group (log-rank test: P = 0.591). Multivariate analysis identified carriers as an independent predictor of cardiovascular events only in the non-CKD group alone (hazard ratio: 8.048; 95% confidence interval: 1.066 to 60.757; P = 0.043).

Conclusions

CYP2C19 polymorphism significantly correlates with clinical outcome in non-CKD patients, and CKD status modifies the association of CYP2C19 polymorphism in predicting clinical outcomes following coronary stent implantation.  相似文献   
74.
75.
76.
77.
Life expectancy (LE) among the Japanese population with or without diabetes mellitus was estimated. LE in 40-year old men and women was 41.1 and 47.5 years in those without diabetes and 32.3 and 40.9 years in those with diabetes. The LE of 40-year old men and women with diabetes was 8.8 and 6.6 years shorter than in those without diabetes. Diabetes mellitus leads to a decrease in LE. The presence of impaired glucose tolerance also affected LE inversely.  相似文献   
78.
Abstract –  An 11‐year‐old male who injured his maxilla and right maxillary central incisor and lip during a fall was presented to our hospital. His lower lip and upper gingiva were lacerated with swelling and epistaxis, and he had a maxillary alveolar bone fracture and severe intrusion of the right maxillary central incisor, which had penetrated the floor of the nasal cavity with avulsion. Under local anesthesia, we repositioned the incisor and bone segment and fixed them with a titanium micromesh plate and self‐tapping screws and splints. The incisor was also treated by root canal 3 days after the operation and was restored with a crown. We performed root canal filling 1 month later. Five months later, the plate and screws were removed. In prognosis of our case, no symptoms of inflammatory root resorption or ankylosis have observed for more than 1 year and 6 months of follow up based on both clinical and radiographic findings.  相似文献   
79.

Background

Mild cerebrospinal fluid (CSF) hypovolemia is a well-known clinical entity, but critical CSF hypovolemia that can cause transtentorial herniation is an unusual and rare clinical entity that occurs after craniotomy. We investigated CSF hypovolemia after microsurgical aneurysmal clipping for subarachnoid hemorrhage (SAH).

Method

This study included 144 consecutive patients with SAH. Lumbar drainage (LD) was inserted after general anesthesia or postoperatively as a standard perioperative protocol. CSF hypovolemia diagnosis was based on three criteria.

Results

Eleven patients (7.6 %) were diagnosed with CSF hypovolemia according to diagnostic criteria in a postoperative range of 0–8 days. In all patients, signs or symptoms of CSF hypovolemia improved within 24 hours by clamping LD and using the Trendelenburg position.

Conclusions

As a cause of acute clinical deterioration after aneurysmal clipping, CSF hypovolemia is likely under-recognized, and may actually be misdiagnosed as vasospasm or brain swelling. We should always take the etiology of CSF hypovolemia into consideration, and especially pay attention in patients with pneumocephalus and subdural fluid collection alongside brain sag on computed tomography. These patients are at higher risk developing of pressure gradients between their cranial and spinal compartments, and therefore, brain sagging after LD, than after ventricular drainage. We should be vigilant to strictly manage LD so as not to produce high pressure gradients.  相似文献   
80.
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