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   871篇
  免费   65篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   16篇
妇产科学   15篇
基础医学   76篇
口腔科学   37篇
临床医学   142篇
内科学   179篇
皮肤病学   37篇
神经病学   40篇
特种医学   109篇
外国民族医学   1篇
外科学   59篇
综合类   47篇
预防医学   56篇
眼科学   33篇
药学   54篇
中国医学   1篇
肿瘤学   33篇
  2022年   22篇
  2021年   21篇
  2020年   16篇
  2019年   19篇
  2018年   30篇
  2017年   23篇
  2016年   13篇
  2015年   22篇
  2014年   26篇
  2013年   39篇
  2012年   13篇
  2011年   24篇
  2010年   41篇
  2009年   35篇
  2008年   17篇
  2007年   20篇
  2006年   19篇
  2005年   14篇
  2004年   13篇
  2003年   18篇
  2002年   14篇
  2001年   18篇
  2000年   16篇
  1999年   12篇
  1998年   21篇
  1997年   14篇
  1996年   25篇
  1995年   18篇
  1994年   25篇
  1993年   32篇
  1992年   16篇
  1991年   12篇
  1989年   20篇
  1988年   17篇
  1987年   12篇
  1986年   9篇
  1985年   16篇
  1984年   8篇
  1983年   10篇
  1982年   10篇
  1981年   14篇
  1980年   14篇
  1979年   12篇
  1978年   7篇
  1977年   11篇
  1957年   9篇
  1955年   6篇
  1954年   6篇
  1949年   8篇
  1948年   8篇
排序方式: 共有937条查询结果,搜索用时 46 毫秒
931.
932.
933.
Bronchopulmonary cancer muscle metastases are uncommon, especially when they are visible. They can impact any muscle in the body, but the psoas, diaphragmatic, and paravertebral muscles have a clear advantage. We present a case of lateral pterygoid muscle metastasis of squamous cell carcinoma of the lung in a 70-year-old habitual smoker (40 packs per year) presents headaches more marked on the right and progressively worsening. A complementary brain MRI revealed a well-limited oval formation with irregular contours in hypo signal T1 hyper signal T2 heterogeneous, with area of central necrosis of the right pterygoid muscle, which was revealed to be a secondary location of bronchopulmonary malignancy after further examination (CT scan of the cervico-thoraco-abdomino-pelvic region, TEP scan, and biopsy). Moreover, muscle metastases are rarely revealing of primary cancer.  相似文献   
934.

Background

There remain few efficacious treatments for bipolar depression, which dominates the course of bipolar disorder (BD). Despite multiple studies reporting associations between depression and cerebral blood flow (CBF), little is known regarding CBF as a treatment target, or predictor and/or indicator of treatment response, in BD. Nitrous oxide, an anesthetic gas with vasoactive and putative antidepressant properties, has a long history as a neuroimaging probe. We undertook an experimental medicine paradigm, coupling in-scanner single-session nitrous oxide treatment of bipolar depression with repeated measures of CBF.

Methods

In this double-blind randomized controlled trial, 25 adults with BD I/II and current treatment-refractory depression received either: (1) nitrous oxide (20 min at 25% concentration) plus intravenous saline (n = 12), or (2) medical air plus intravenous midazolam (2 mg total; n = 13). Study outcomes included changes in depression severity (Montgomery-Asberg Depression Rating Scale scores, primary) and changes in CBF (via arterial spin labeling magnetic resonance imaging).

Results

There were no significant between-group differences in 24-h post-treatment MADRS change or treatment response. However, the nitrous oxide group had significantly greater same-day reductions in depression severity. Lower baseline regional CBF predicted greater 24-h post-treatment MADRS reductions with nitrous oxide but not midazolam. In region-of-interest and voxel-wise analyses, there was a pattern of regional CBF reductions following treatment with midazolam versus nitrous oxide.

Conclusions

Present findings, while tentative and based on secondary endpoints, suggest differential associations of nitrous oxide versus midazolam with bipolar depression severity and cerebral hemodynamics. Larger studies integrating neuroimaging targets and repeated nitrous oxide treatment sessions are warranted.  相似文献   
935.

Background

Sulfonylureas are oral glucose-lowering medications positioned as a second-line therapy for type 2 diabetes. Evidence relating them to cognitive decline has been mixed. The objective was to determine whether sulfonylurea use was associated with a differential risk of dementia compared with dipeptidyl peptidase-4 (DPP4) inhibitor use.

Methods

Using administrative data from residents in Ontario, Canada, adults aged ≥66 years who were new users of a sulfonylurea or a DPP4 inhibitor from June 14, 2011, to March 31, 2021 entered this population-based retrospective cohort study. Dementia was ascertained using a validated algorithm for Alzheimer's disease and related dementias. Propensity-score weighted Cox proportional hazards models were used to obtain adjusted hazard ratios (aHR) and confidence intervals (CI) for time to incident dementia. The observation window started at 1 year after cohort entry to mitigate protopathic bias due to delayed diagnosis. The primary analysis used an intention-to-treat exposure definition. A separate propensity-score weighted analysis was conducted to explore within-class differences in dementia risk among sulfonylurea new users selected from the primary cohort.

Results

Among 107,806 DPP4 inhibitor new users and 37,030 sulfonylurea new users, sulfonylureas compared with DPP4 inhibitors were associated with a higher risk of dementia (18.4/1000 person-years; aHR [95% CI] = 1.09 [1.04–1.15]) over a mean follow-up of 4.82 years from cohort entry. Glyburide compared to gliclazide exhibited a higher dementia risk (aHR [95% CI] = 1.17 [1.03–1.32]).

Conclusion

New use of a sulfonylurea especially glyburide was associated with a higher dementia risk compared with new use of a DPP4 inhibitor in older adults with diabetes.  相似文献   
936.
Post-traumatic hepatic biloma is a rare complication of closed trauma of the abdomen. Generally, biloma occurs spontaneously or secondary to traumatic or iatrogenic injury to the biliary system. It can lead to significant morbidity and mortality if not diagnosed promptly and properly managed. A 4-year-old child was admitted to the emergency room with abdominal pain following a traffic accident. Clinical examinations suspected closed abdominal trauma without biological signs of icteric cholestasis. Abdominal CT scan performed within 24 hours showed a focus of hepatic laceration, and follow-up imaging at 5 days showed post-traumatic intrahepatic cystic formations. This case report aims to emphasize the importance of imaging including ultrasound, CT, MRI, MRI cholangiopancreatography (MRCP), or hepatobiliary cholescintigraphy to establish the diagnosis and guide the therapeutic gestures.  相似文献   
937.
Mediastinal bronchial artery aneurysm is very rare and only few cases have been reported in the literature. The clinical presentations are varied, ranging from an incidental radiological finding to a cataclysmic rupture leading to hemorrhagic shock. Thus, a quick treatment is indicated upon diagnosis. Therapeutic options are various including surgical resection, stent grafting with percutaneous embolization of feeding vessel or transtarterial embolization. Herein we describe a case of an incidental mediastinal bronchial artery aneurysm in a 63-year-old man, managed by transtarterial embolization.  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