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   2759篇
  免费   254篇
  国内免费   10篇
耳鼻咽喉   17篇
儿科学   60篇
妇产科学   35篇
基础医学   380篇
口腔科学   91篇
临床医学   323篇
内科学   597篇
皮肤病学   18篇
神经病学   285篇
特种医学   206篇
外科学   305篇
综合类   73篇
预防医学   250篇
眼科学   17篇
药学   166篇
肿瘤学   200篇
  2022年   24篇
  2021年   39篇
  2020年   35篇
  2019年   32篇
  2018年   42篇
  2017年   32篇
  2016年   41篇
  2015年   42篇
  2014年   44篇
  2013年   95篇
  2012年   115篇
  2011年   124篇
  2010年   73篇
  2009年   76篇
  2008年   111篇
  2007年   101篇
  2006年   105篇
  2005年   97篇
  2004年   105篇
  2003年   103篇
  2002年   94篇
  2001年   77篇
  2000年   80篇
  1999年   92篇
  1998年   61篇
  1997年   59篇
  1996年   54篇
  1995年   48篇
  1994年   46篇
  1993年   38篇
  1992年   68篇
  1991年   65篇
  1990年   59篇
  1989年   60篇
  1988年   49篇
  1987年   53篇
  1986年   57篇
  1985年   65篇
  1984年   28篇
  1983年   26篇
  1981年   21篇
  1979年   26篇
  1976年   20篇
  1975年   20篇
  1974年   26篇
  1973年   21篇
  1972年   24篇
  1971年   21篇
  1968年   20篇
  1966年   20篇
排序方式: 共有3023条查询结果,搜索用时 15 毫秒
71.

Purpose

Pulmonary edema (PE) is associated with fluid accumulation in the lungs. Device-based impedance measurements have been used to detect fluid overload prior to hospitalization. However, studies have reported a high false positive rate (FPR). The objective of this study was to develop and test a new multivector impedance-based algorithm that reliably tracks PE clinical events.

Methods

We enrolled patients with implanted CRT-Ds in 23 US centers within 2 weeks of device implant. Six-vector impedance data was collected automatically by the CRT-Ds every 30 min during emergency department visits/hospitalizations and every 2 h at all other times. Detection algorithms for cardiac resynchronization therapy defibrillator (CRT-D) and implantable cardiac defibrillator (ICD) devices were developed using those impedance vectors that would be available in corresponding devices and retrospectively evaluated.

Results

There were 75 patients (69 % male), mean age 66?±?12 years, with a LVEF of 23?±?6 % and QRS of 149?±?25 ms. Twenty-one major clinical events occurred over 8.2?±?2.6 months of follow-up time. CRT-D vector combinations resulted in a sensitivity of 71.4 % (95 % confidence interval 47.8–88.7) and a FPR of 0.56 (0.30–0.94) false positives per patient-year (FPs/pt-yr); ICD vector combinations resulted in a sensitivity of 61.9 % (38.4–81.9) and a FPR of 0.63 (0.36–0.90) FPs/pt-yr. In comparison, the single-vector RVCoil-Can implementation of this algorithm resulted in a sensitivity of 57.1 % (34.0–78.2) and a FPR of 0.74 (0.44–1.12) FPs/pt-yr.

Conclusions

This multivector impedance algorithm was effective in tracking PE clinical events in this patient population. Additional studies are needed to prospectively evaluate the performance of this algorithm in a larger population.  相似文献   
72.
Aim: To obtain experts' estimates of the number of non‐medical care hours required by older Singaporeans at different stages of ageing‐related dementia, with low or high behavioural features. Methods: Experts on dementia in Singapore attended one of two meetings where they provided estimates of the number of care hours required for individuals at mild, moderate and severe levels of dementia with either low or high behavioural features. The experts were shown the collated responses, given an opportunity to discuss as a group, and then polled again. Results: The estimated mean care hours varied by dementia severity and the level of behavioural features. There was no interaction between dementia severity and behavioural features. Conclusion: Estimated care hours needed by individuals with dementia is independently influenced by severity of dementia and behavioural features. These estimates may be useful for policy‐makers in projecting the impact of caregiving.  相似文献   
73.
74.
Pain, swelling, trismus, and alveolar osteitis often occur after removal of impacted third molar teeth. To minimize these complications a number of mucoperiosteal flap designs have been advocated, but, to date, a pedicle flap design has not been evaluated. In a randomized prospective split mouth study, 52 participants had bilateral symmetrically impacted mandibular third molars removed over two sessions. A buccal envelope or pedicle flap was randomly assigned to the left or right third molar site. Pre-and postoperative pain and swelling were recorded using a standardized visual analogue scale, trismus was measured as the maximum inter-incisal opening distance in millimetres and dry socket was assessed clinically. Greater continuous pain, pain on maximum opening, and oro-facial swelling were recorded with the pedicle flap design. Continuous pain resolved significantly faster with this flap design (p<0.05). Trismus was similar for both flap designs (p>0.05). Five cases of alveolar osteitis occurred with the envelope flap whilst no cases developed with the pedicle flap, but the incidence was too small for statistical analysis. The pedicle flap improved some aspects of postoperative pain experience and reduced the incidence of alveolar osteitis, but further investigation with a larger sample size is required to evaluate its significance.  相似文献   
75.
Lasers in Medical Science - Dental pulp cells are a source of multipotent mesenchymal stem cells with a high proliferation rate and multilineage differentiation potential. This study investigated...  相似文献   
76.
77.
78.
Aims: The IATPAD (Improvement in Access to Treatment for People with Alcohol and Drug Related Problems) study explored barriers and facilitators to accessing alcohol and drug treatment services in eight European countries.

Methods: Results from individual interviews and focus group discussions with 246 service users who had experienced alcohol and drug treatment in Bulgaria, Greece, Italy, Poland, Slovakia, Slovenia, Spain and Scotland are described. Thematic analysis was used to interpret the data.

Results: The study identified a number of consistent facilitating factors and barriers across all eight European countries, despite different health care systems. The results suggest that five main factors were implicated in the help-seeking behaviour of the service users interviewed. These were: information, service organisation, staff attitudes, significant others and personal disposition. All these factors could be viewed as both facilitators and barriers.

Conclusions: To enhance access to alcohol and drug treatment, local, non-stigmatising and available services are required alongside support from significant others which should increase motivation and skills of potential service users.  相似文献   

79.
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