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   2052篇
  免费   153篇
  国内免费   9篇
耳鼻咽喉   31篇
儿科学   70篇
妇产科学   63篇
基础医学   236篇
口腔科学   33篇
临床医学   397篇
内科学   345篇
皮肤病学   8篇
神经病学   207篇
特种医学   77篇
外科学   251篇
综合类   17篇
预防医学   201篇
眼科学   15篇
药学   169篇
中国医学   10篇
肿瘤学   84篇
  2021年   23篇
  2020年   20篇
  2019年   39篇
  2018年   55篇
  2017年   35篇
  2016年   31篇
  2015年   35篇
  2014年   48篇
  2013年   76篇
  2012年   91篇
  2011年   85篇
  2010年   49篇
  2009年   53篇
  2008年   90篇
  2007年   80篇
  2006年   82篇
  2005年   62篇
  2004年   66篇
  2003年   73篇
  2002年   68篇
  2001年   77篇
  2000年   56篇
  1999年   77篇
  1998年   42篇
  1997年   29篇
  1996年   37篇
  1995年   23篇
  1994年   28篇
  1993年   18篇
  1992年   52篇
  1991年   38篇
  1990年   37篇
  1989年   41篇
  1988年   42篇
  1987年   32篇
  1986年   37篇
  1985年   36篇
  1984年   26篇
  1983年   28篇
  1982年   31篇
  1981年   16篇
  1980年   19篇
  1979年   28篇
  1978年   13篇
  1975年   12篇
  1974年   13篇
  1972年   18篇
  1971年   12篇
  1969年   13篇
  1968年   20篇
排序方式: 共有2214条查询结果,搜索用时 296 毫秒
21.
22.
23.
Draize rabbit eye test scores, as modified maximum average score (MMAS), for 68 pure bulk liquids were adjusted by the liquid-saturated vapor pressure P. These 68 adjusted scores, as log (MMAS/P), were shown to be completely equivalent to eye irritation thresholds (EIT), expressed as log (1/EIT), for 23 compounds in humans. Thus, for the first time the Draize eye test in rabbits for pure bulk liquids is shown to be perfectly compatible with eye irritation thresholds in humans. The total data set for 91 compounds was analyzed by the general solvation equation of Abraham. Values of log (MMAS/P) or log (1/EIT) could be fitted to a five-parameter equation with R2 = 0.936, SD = 0.433, AD = 0.000, and AAD = 0.340 over a range of 9.6 log units. When divided into a training set of 45 compounds, the corresponding equation could be used to predict the remaining 46 compounds in a test set with AD = -0.037 and AAD = 0.345 log units. Thus, the 91-compound equation can now be used to predict further EIT values to around 0.4 log units. It is suggested that the mechanism of action in the Draize test and in the human EIT involves passive transfer of the compound to a biophase that is quite polar, is a strong hydrogen bond base, a moderate hydrogen bond acid, and quite hydrophobic. The biophase does not resemble water or plasma, but resembles an organic solvent such as N-methylformamide.  相似文献   
24.
25.
Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.  相似文献   
26.
27.

Background

The Veterans Health Administration (VHA) faces challenges in providing comprehensive, gender-sensitive care for women. National policies have led to important advancements, but local leadership also plays a vital role in implementing changes and operationalizing national priorities. In this article, we explore the notions of ideal women veterans' health care articulated by women's health leaders at local VHA facilities and regional networks, with the goal of identifying elements that could inform practice and policy.

Methods

We conducted semistructured interviews with 86 local and regional women's health leaders at 12 VHA medical centers across four regions. At the conclusion of interviews about women's primary care, participants were asked to imagine “ideal care” for women veterans. Interviews were transcribed and coded using a hybrid inductive/deductive approach.

Results

In describing ideal care, participants commonly touched on whether women veterans should have separate primary care services from men; the need for childcare, expanded reproductive health services, resources, and staffing; geographic accessibility; the value of input from women veterans; the physical appearance of facilities; fostering active interest in women's health across providers and staff; and the relative priority of women's health at the VHA.

Conclusions

Policy and practice changes to care for women veterans must be mindful of key stakeholders' vision for that care. Specific features of that vision include clinic construction that anticipates a growing patient population, providing childcare and expanded reproductive health services, ensuring adequate support staff, expanding mechanisms to incorporate women veterans' input, and fostering a culture oriented towards women's health at the organizational level.  相似文献   
28.
It is time for colleges and schools of pharmacy to examine and confront the rising costs of pharmacy education and the increasing student loan debt borne by graduates. These phenomena likely result from a variety of complex factors. The academy should begin addressing these issues before pharmacy education becomes cost-prohibitive for future generations. This paper discusses some of the more salient drivers of cost and student debt load and offers suggestions that may help alleviate some of the financial pressures.  相似文献   
29.
Bubble-induced color Doppler (BCD) is a histotripsy-therapy monitoring technique that uses Doppler ultrasound to track the motion of residual cavitation nuclei that persist after the collapse of the histotripsy bubble cloud. In this study, BCD is used to monitor tissue fractionation during histotripsy tissue therapy, and the BCD signal is correlated with the destruction of structural and non-structural components identified histologically to further understand how BCD monitors the extent of treatment. A 500-kHz, 112-element phased histotripsy array is used to generate approximately 6-?×?6-?×?7-mm lesions within ex vivo bovine liver tissue by scanning more than 219 locations with 30–1000 pulses per location. A 128-element L7-4 imaging probe is used to acquire BCD signals during all treatments. The BCD signal is then quantitatively analyzed using the time-to-peak rebound velocity (tprv) metric. Using the Pearson correlation coefficient, the tprv is compared with histologic analytics of lesions generated by various numbers of pulses using a significance level of 0.001. Histologic analytics in this study include viable cell count, reticulin-stained type III collagen area and trichrome-stained type I collagen area. It is found that the tprv metric has a statistically significant correlation with the change in reticulin-stained type III collagen area with a Pearson correlation coefficient of ?0.94 (p?<0.001), indicating that changes in BCD are more likely because of destruction of the structural components of tissue.  相似文献   
30.
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