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   1847篇
  免费   142篇
  国内免费   5篇
耳鼻咽喉   14篇
儿科学   79篇
妇产科学   33篇
基础医学   323篇
口腔科学   12篇
临床医学   169篇
内科学   573篇
皮肤病学   11篇
神经病学   138篇
特种医学   54篇
外科学   159篇
综合类   19篇
一般理论   2篇
预防医学   226篇
眼科学   23篇
药学   76篇
肿瘤学   83篇
  2022年   21篇
  2021年   22篇
  2020年   16篇
  2019年   27篇
  2018年   36篇
  2017年   29篇
  2016年   36篇
  2015年   34篇
  2014年   45篇
  2013年   48篇
  2012年   84篇
  2011年   78篇
  2010年   56篇
  2009年   37篇
  2008年   88篇
  2007年   88篇
  2006年   94篇
  2005年   83篇
  2004年   64篇
  2003年   66篇
  2002年   56篇
  2001年   69篇
  2000年   59篇
  1999年   42篇
  1998年   21篇
  1997年   13篇
  1996年   18篇
  1995年   21篇
  1994年   9篇
  1993年   9篇
  1992年   31篇
  1991年   41篇
  1990年   39篇
  1989年   49篇
  1988年   36篇
  1987年   39篇
  1986年   39篇
  1985年   39篇
  1984年   19篇
  1983年   27篇
  1982年   13篇
  1981年   17篇
  1980年   23篇
  1979年   17篇
  1978年   19篇
  1976年   13篇
  1975年   14篇
  1974年   16篇
  1973年   17篇
  1972年   11篇
排序方式: 共有1994条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Previous studies have suggested that corticotropin-releasing factor (CRF) has immunoregulatory effects in addition to its neuroendocrine role. We examined the ability of CRF to inhibit lipopolysaccharide (LPS)-induced pulmonary vascular leak in vivo. Female BALB/C mice were treated with either normal saline (NS) or CRF prior to injection with LPS. Pulmonary vascular leak was inhibited by CRF as assessed by measurement of lung wet-to-dry ratios. The stress-induced increase in serum corticosterone levels in mice injected with LPS alone was not further increased by treatment with CRF. This indicates that the effect of CRF was not mediated centrally by stimulation of endogenous steroid release. Histologic examination of the lungs revealed that leukocyte infiltration was significantly depressed in CRF-treated mice thus confirming the protective effect of CRF. In addition, a modest prolongation of survival was demonstrated in CRF-treated mice following challenge with LPS (p=.08). These data indicate the potential utility of CRF as a modulator of pulmonary vascular leak.  相似文献   
7.
OBJECTIVES. Primary care medical clinics are good settings for smoking interventions. This study extends this strategy with a smokeless tobacco intervention delivered by dentists and dental hygienists in the course of routine dental care. METHODS. Male users of moist snuff and chewing tobacco (n = 518) were identified by questionnaire in clinic waiting rooms and then randomly assigned to either usual care or intervention. The intervention included a routine oral examination with special attention to the part of the mouth in which tobacco was kept and an explanation of the health risks of using smokeless tobacco. After receiving unequivocal advice to stop using tobacco, each patient viewed a 9-minute videotape, received a self-help manual, and was briefly counseled by the dental hygienist. RESULTS. Long-term success was defined as no smokeless tobacco use at both 3- and 12-month follow-ups, with those lost to follow-up counted as smokeless tobacco users. The intervention increased the proportion of patients who quit by about one half (12.5% vs 18.4%, P < .05). CONCLUSIONS. These results demonstrate the efficacy of a brief dental office intervention for the general population of smokeless tobacco users.  相似文献   
8.
ABSTRACT: Given the increasing prevalence of schoolchildren's experience with crises and resulting loss through sudden or violent death, adoption of a school-based crisis prevention and response plan becomes crucial. This article reviews a model of regional, district, and school-based levels of response designed collaboratively by four school districts and consultants from Yale University. The team approach on which the model is based is examined through benefits it affords students, staff, parents, and the community. Obstacles that can impede full implementation of the model are identified, and strategies for overcoming logistical and systemic resistances are offered. This proactive design helps promote individual and organizational resiliency to traumatic events by promoting communication, collaboration, and service provision in an efficient and comprehensive manner.  相似文献   
9.
Summary The tension-free hernioplasty project began in 1984 at the Lichtenstein Hernia Institute. The method consists of complete reinforcement of the inguinal floor with a large sheet of mesh, with adequate mesh tissue interface beyond the boundary of the inguinal floor and creation of a new internal ring made of prosthesis. The preliminary report of this operation was published in 1989, with no recurrence at that point in time. Shortly after the submission of the report, several recurrences were encountered. Based on the lesson learned from those recurrences, the operation was slightly modified and reported in 1991 [Amid 1993]. Since then, the Lichtenstein technique has gained world-wide popularity. Outcome measures identical to ours and other authors have been achieved by even those surgeons who have no special interest or expertise in herniology. The purpose of this article is to report the current state of the open tension-free hernioplasty for the repair of primary and recurrent inguinal hernias.  相似文献   
10.
The presence of metastases in the regional lymph nodes is the major prognostic factor in breast cancer in the absence of overt distant metastases and is also an important indicator of the need for adjuvant therapy in "early" breast cancer. Currently, the accurate assessment of axillary lymph node status requires axillary dissection which has an associated morbidity. An alternative method of identifying patients who are "node positive" has been developed by means of immunolymphoscintigraphy with s.c. administered radioiodinated monoclonal antibody. The 131I-labeled anti-breast cancer antibody (RCC-1; 400 micrograms) and cold iodine-labeled "blocking" antibody (Ly-2.1; 2 mg which is nonreactive with breast cancer) were injected s.c. into both arms and scintigraphy images were obtained 16-18 h after the injection, using the axilla contralateral to the side of the breast cancer as the control. Studies were reported as positive (and therefore indicative of lymph node metastases) if the amount of background-subtracted radioactive count in the axilla of interest exceeded the normal side by a radio equal to or greater than 1.5:1.0 as assessed by computer analysis. In 38 of 40 patients the findings on scintigraphy were correlated with operative and histopathological findings on the axillary dissection specimen or cytological findings of fine needle aspiration of axillary lymph nodes. In a prospective study of 26 patients, the method is more sensitive (86%) and specific (92%) than preoperative clinical assessment (57% sensitivity, 58% specificity) in the detection of axillary lymph node metastases; and by combining both modalities of assessment, there was an improvement in the sensitivity (100%) but a deterioration in the specificity (50%). There was no significant complication from this essentially outpatient procedure and only 1 of 40 patients developed a human anti-mouse antibody response. This novel and safe method of imaging may become a most useful adjunct in the surgical management of breast cancer.  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