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   10595篇
  免费   609篇
  国内免费   52篇
耳鼻咽喉   107篇
儿科学   269篇
妇产科学   137篇
基础医学   1531篇
口腔科学   272篇
临床医学   997篇
内科学   2080篇
皮肤病学   252篇
神经病学   1150篇
特种医学   622篇
外科学   1448篇
综合类   44篇
一般理论   2篇
预防医学   605篇
眼科学   217篇
药学   734篇
中国医学   18篇
肿瘤学   771篇
  2023年   43篇
  2022年   36篇
  2021年   175篇
  2020年   129篇
  2019年   177篇
  2018年   235篇
  2017年   160篇
  2016年   249篇
  2015年   297篇
  2014年   386篇
  2013年   444篇
  2012年   707篇
  2011年   699篇
  2010年   446篇
  2009年   454篇
  2008年   645篇
  2007年   675篇
  2006年   736篇
  2005年   712篇
  2004年   683篇
  2003年   648篇
  2002年   563篇
  2001年   142篇
  2000年   122篇
  1999年   104篇
  1998年   130篇
  1997年   67篇
  1996年   61篇
  1995年   73篇
  1994年   73篇
  1993年   60篇
  1992年   64篇
  1991年   52篇
  1990年   51篇
  1989年   46篇
  1988年   45篇
  1987年   44篇
  1986年   33篇
  1985年   42篇
  1984年   43篇
  1983年   42篇
  1982年   32篇
  1981年   20篇
  1980年   29篇
  1979年   28篇
  1978年   40篇
  1977年   19篇
  1976年   26篇
  1968年   17篇
  1954年   25篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Patients admitted to intensive care after cardiac arrest are at risk of circulatory shock and early mortality due to cardiovascular failure. The aim of this study was to evaluate the ability of the veno-arterial pCO2 difference (∆pCO2; central venous CO2 – arterial CO2) and lactate to predict early mortality in postcardiac arrest patients. This was a pre-planned prospective observational sub-study of the target temperature management 2 trial. The sub-study patients were included at five Swedish sites. Repeated measurements of ∆pCO2 and lactate were conducted at 4, 8, 12, 16, 24, 48, and 72 h after randomization. We assessed the association between each marker and 96-h mortality and their prognostic value for 96-h mortality. One hundred sixty-three patients were included in the analysis. Mortality at 96 h was 17%. During the initial 24 h, there was no difference in ∆pCO2 levels between 96-h survivors and non-survivors. ∆pCO2 measured at 4 h was associated with an increased risk of death within 96 h (adjusted odds ratio: 1.15; 95% confidence interval [CI]: 1.02–1.29; p = .018). Lactate levels were associated with poor outcome over multiple measurements. The area under the receiving operating curve to predict death within 96 h was 0.59 (95% CI: 0.48–0.74) and 0.82 (95% CI: 0.72–0.92) for ∆pCO2 and lactate, respectively. Our results do not support the use of ∆pCO2 to identify patients with early mortality in the postresuscitation phase. In contrast, non-survivors demonstrated higher lactate levels in the initial phase and lactate identified patients with early mortality with moderate accuracy.  相似文献   
2.
Die Anaesthesiologie - Phantomschmerzen haben eine hohe Prävalenz nach Majoramputationen und sind mit einer zusätzlichen Einschränkung der Lebensqualität verbunden....  相似文献   
3.
Die Anaesthesiologie - Die Implementierung eines Patient Blood Management (PBM) wird zunehmender Standard in der operativen Medizin. Seit einiger Zeit gilt das Interesse auch den vulnerablen...  相似文献   
4.
5.

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) without and with cervical plating (ACDF+CP) are accepted surgical techniques for the treatment of degenerative cervical disc disorders. The effect of CP on the development of adjacent segment degeneration (ASD) remains unclear.

PURPOSE

To assess whether CP accelerates the degeneration of the adjacent and adjoining segments.

STUDY DESIGN/SETTING

This is an imaging cohort study.

PATIENT SAMPLE

Retrospectively, a total of 84 patients who underwent ACDF or ACDF+CP were identified. At final follow-up, an MRI was performed and evaluated in this study.

MATERIALS AND METHODS

An MRI of 84 patients who underwent ACDF (46 patients) and ACDF+PS (38 patients) was performed. The mean follow-up was 24 years (17–45 years). None of the patients had a repeat procedure in the cervical spine. The grade of degeneration of the segments adjacent and adjoining to the fusion was assessed via a five-step grading system (segmental degeneration index, or SDI) that includes disc signal intensity, anterior and posterior disc protrusion, narrowing of the disc space, and foraminal stenosis. Furthermore, the disc height (DH) and sagittal segmental angle (SSA) of fused segments were measured.

RESULTS

A significantly (p<.001) greater SDI was identified at the caudal adjacent segment following ACDF compared to ACDF+CP. No other significant differences were identified in patients following ACDF and ACDF+CP. Between 50% and 96% of all segments showed severe degenerative changes according to SDI. There was no significant difference in DH between the patients following ACDF and ACDF+CP. The SSA in patients who underwent ACDF+CP was significantly greater than in the ACDF patients (p=.002).

CONCLUSIONS

In this cohort of patients, cervical plating had no significant impact on segmental degeneration and decrease of DH in the adjacent and adjoining segments. ACDF+CP seem to preserve the lordotic alignment more with respect to the SSA than ACDF.  相似文献   
6.
Evidence on survival of malignant mesothelioma (MM) and other rare thoracic cancers is limited due to the rarity of these cancer sites. Here, we provide a comprehensive overview of MM incidence and survival after MM and other rare thoracic cancers in Germany and the United States (US). Incidence was estimated from a German National Cancer Database and from the Surveillance, Epidemiology and End Results (SEER) 18 database for 2000–2014. Patients diagnosed in 1997–2013 with malignant epithelial tumors of the trachea (Etra), epithelial tumors of the thymus (Ethy) and MM were extracted from a German cancer survival database and from the SEER 13 database. Period analysis was employed to compute 5-year relative survival (RS). During 2000–2014, an annual average of 0.9 and 0.6 MM cases per 100,000 person-years was diagnosed in Germany and the US. Rates decreased in Germany and in the US. Patients with Ethy had highest 5-year RS with US patients surviving longer (69.1% compared to 63.7%, p = 0.02). Survival after Etra was comparable in both countries (Germany 33.6%, US 34.4%, p = 0.07). Survival in MM patients was poor overall (Germany 11.8%, US 12.1%, p < 0.01). Survival improvements were only observed in MM patients in Germany (10.8% [2002–2007] vs. 13.0% [2008–2013], p < 0.01). The lack of progress in survival for Etra and Ethy patients underlines the need of novel preventive, therapeutic and diagnostic approaches. MM incidence significantly decreased in Germany and in the US. Further monitoring of MM incidence is warranted given that a peak in incidence is expected in 2020–2030 in Western countries.  相似文献   
7.
8.
The resistant and recalcitrant nature of severe allergic contact dermatitis (ACD) makes its management challenging. With advances in the understanding of the cellular and molecular pathogenesis of ACD, newer therapeutic targets are becoming apparent. In particular, the use of biologics has gained momentum, given the specificity of their action. This article aims to review the presently available data on the use of biologics in ACD. English-language–based literature available on the use of biological therapy was thoroughly probed in the following databases as on October 14, 2019: PubMed, Google Scholar, The Cochrane library, Embase, Scopus, and EBSCO. The following keywords were used: “contact dermatitis”, “allergens”, “delayed-type hypersensitivity reaction”, “biologics”, “biological therapy”, “monoclonal antibodies”, “patch testing”, “TNF-α inhibitors”, “infliximab”, “adalimumab”, “etanercept”, “dupilumab”, “omalizumab”, “secukinumab”, “ustekinumab”, “rituximab”.  相似文献   
9.
10.
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