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   1615篇
  免费   119篇
  国内免费   14篇
耳鼻咽喉   5篇
儿科学   34篇
妇产科学   38篇
基础医学   269篇
口腔科学   87篇
临床医学   141篇
内科学   386篇
皮肤病学   45篇
神经病学   178篇
特种医学   51篇
外科学   118篇
综合类   2篇
一般理论   1篇
预防医学   107篇
眼科学   51篇
药学   112篇
中国医学   4篇
肿瘤学   119篇
  2023年   13篇
  2022年   28篇
  2021年   66篇
  2020年   38篇
  2019年   56篇
  2018年   61篇
  2017年   64篇
  2016年   56篇
  2015年   64篇
  2014年   89篇
  2013年   95篇
  2012年   142篇
  2011年   159篇
  2010年   80篇
  2009年   61篇
  2008年   85篇
  2007年   89篇
  2006年   91篇
  2005年   105篇
  2004年   68篇
  2003年   64篇
  2002年   46篇
  2001年   15篇
  2000年   11篇
  1999年   2篇
  1998年   6篇
  1997年   8篇
  1996年   4篇
  1995年   5篇
  1994年   3篇
  1993年   6篇
  1992年   8篇
  1991年   4篇
  1990年   6篇
  1989年   9篇
  1988年   5篇
  1987年   2篇
  1986年   4篇
  1985年   2篇
  1984年   2篇
  1983年   3篇
  1981年   6篇
  1980年   2篇
  1979年   3篇
  1977年   2篇
  1975年   1篇
  1974年   3篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有1748条查询结果,搜索用时 31 毫秒
41.
Impaired balance and gait performance increase fall-risk in seniors. Acute effects of different exercise bouts on gait and balance were not yet addressed. Therefore, 19 healthy seniors (10 women, 9 men, age: 64.6 ± 3.2 years) were examined on 3 days. After exhaustive treadmill testing, participants randomly completed a 2-km treadmill walking test (76 ± 8 % VO2max) and a resting control condition. Standing balance performance (SBALP) was assessed by single limb-eyes opened (SLEO) and double limb-eyes closed (DLEC) stance. Gait parameters were collected at comfortable walking velocity. A condition × time interaction of center of pressure path length (COPpath) was observed for both balance tasks (p < 0.001). Small (Cohen’s d = 0.42, p = 0.05) and large (d = 1.04, p < 0.001) COPpath increases were found after 2-km and maximal exercise during DLEC. Regarding SLEO, slightly increased COPpath occurred after 2-km walking (d = 0.29, p = 0.65) and large increases after exhaustive exercise (d = 1.24, p < 0.001). No significant differences were found for gait parameters. Alterations of SBALP after exhaustive exercise might lead to higher fall-risk in seniors. Balance changes upon 2-km testing might be of minor relevance. Gait is not affected during single task walking at given velocities.  相似文献   
42.
43.
The International Journal of Cardiovascular Imaging - The aim of our study was to assess the anatomical changes of the mitral valve apparatus after percutaneous repair with the MitraClip®...  相似文献   
44.
45.

Background

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis. Gemcitabine is the standard chemotherapy for patients with metastatic pancreatic adenocarcinoma (MPA). Randomized clinical trials evaluating intensified chemotherapies including FOLFIRINOX and nab-paclitaxel plus gemcitabine (NAB+GEM) have shown improvement in survival. Here, we have evaluated the efficacy of intensified chemotherapy versus gemcitabine monotherapy in real-life settings across Europe.

Methods

A retrospective multi-center study including 1056 MPA patients, between 2012 and 2015, from nine centers in UK, Germany, Italy, Hungary and the Swedish registry was performed. Follow-up was at least 12 months. Cox proportional Harzards regression was used for uni- and multivariable evaluation of prognostic factors.

Results

Of 1056 MPA patients, 1030 (98.7%) were assessable for survival analysis. Gemcitabine monotherapy was the most commonly used regimen (41.3%), compared to FOLFIRINOX (n = 204, 19.3%), NAB+GEM (n = 81, 7.7%) and other gemcitabine- or 5-FU-based regimens (n = 335, 31.7%). The median overall survival (OS) was: FOLFIRINOX 9.9 months (95%CI 8.4–12.6), NAB+GEM 7.9 months (95%CI 6.2–10.0), other combinations 8.5 months (95%CI 7.7–9.3) and gemcitabine monotherapy 4.9 months (95%CI 4.4–5.6). Compared to gemcitabine monotherapy, any combination of chemotherapeutics improved the survival with no significant difference between the intensified regimens. Multivariable analysis showed an association between treatment center, male gender, inoperability at diagnosis and performance status (ECOG 1–3) with poor prognosis.

Conclusion

Gemcitabine monotherapy was predominantly used in 2012–2015. Intensified chemotherapy improved OS in comparison to gemcitabine monotherapy. In real-life settings, the OS rates of different treatment approaches are lower than shown in randomized phase III trials.  相似文献   
46.
CTX-M-131 is a natural Asp240Gly variant from the CTX-M-2 group detected in a Providencia rettgeri clinical strain from Brazil. Molecular analysis showed that blaCTX-M-131 was inserted in a complex class 1 integron harbored by a 112-kb plasmid, which has not been previously described as a platform for CTX-M-encoding genes with the Asp240Gly mutation. Steady-state kinetic parameters showed that the enzyme has a typical cefotaximase catalytic profile and an enhanced activity against ceftazidime.  相似文献   
47.
While ocular syphilis is not a new phenomenon, recent increased rates of new diagnoses, especially in human immunodeficiency virus (HIV)-infected persons and men who have sex with men, have sparked a new interest in an old disease. This article will review the clinical presentation, diagnosis, and treatment of ocular syphilis, and provide guidance on management.  相似文献   
48.
49.

Background

The aim of the study was to focus the awareness of complications of oral piercing among a group of adolescents and young Italian adults with intraoral piercings.

Material and Methods

A total of 225 teenagers were asked to complete a questionnaire on the awareness of complications of oral piercing. An additional questionnaire was administered in case of oral piercing worn, based on site piercing, knowledge about piercer license, oral and systemic risks due to oral piercing, disinfection and sterilization of the material pierced, information by the piercer about piercing hygiene maintenance and post-piercing dentist check-up. After questionnaire all partecipants received a brochure with some information about risks and maintenance mode of piercing.

Results

Data revealed that more than 50% of teens surveyed was found to wear a piercing. Only 25.3% was aware of the risk of HCV cross-infection and only 17.3% reported of knowledge about risk of endocarditis. Only 17% checked the piercer license and only 18% sterilization and disinfection of the materials used. 53.7% did not received explanations about the risks associated with piercing. With regard to the maintenance mode of the piercing, it has been suggested to brush the piercing bar in 17% of cases. The post piercing specialist visits have been suggested only in 7% of cases.

Conclusions

The general lack of awareness of complications and maintenance mode related to oral piercing needs to be addressed by some education programs performed at school and by dentists. Key words: Oral piercing, oral health, oral complications.  相似文献   
50.
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