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   1728篇
  免费   152篇
  国内免费   4篇
耳鼻咽喉   38篇
儿科学   45篇
妇产科学   39篇
基础医学   233篇
口腔科学   17篇
临床医学   258篇
内科学   318篇
皮肤病学   31篇
神经病学   145篇
特种医学   50篇
外科学   222篇
综合类   16篇
现状与发展   1篇
一般理论   2篇
预防医学   240篇
眼科学   17篇
药学   104篇
中国医学   1篇
肿瘤学   107篇
  2023年   29篇
  2022年   11篇
  2021年   43篇
  2020年   53篇
  2019年   70篇
  2018年   76篇
  2017年   69篇
  2016年   52篇
  2015年   49篇
  2014年   75篇
  2013年   119篇
  2012年   123篇
  2011年   141篇
  2010年   51篇
  2009年   51篇
  2008年   93篇
  2007年   95篇
  2006年   74篇
  2005年   77篇
  2004年   70篇
  2003年   55篇
  2002年   64篇
  2001年   30篇
  2000年   22篇
  1999年   24篇
  1998年   11篇
  1995年   7篇
  1993年   6篇
  1992年   18篇
  1991年   15篇
  1990年   8篇
  1989年   17篇
  1988年   13篇
  1987年   9篇
  1986年   11篇
  1985年   8篇
  1984年   13篇
  1983年   12篇
  1982年   9篇
  1981年   7篇
  1980年   5篇
  1979年   12篇
  1978年   5篇
  1977年   5篇
  1975年   9篇
  1974年   8篇
  1973年   5篇
  1972年   11篇
  1971年   6篇
  1970年   5篇
排序方式: 共有1884条查询结果,搜索用时 15 毫秒
101.
Transradial coronary intervention is usually performed via a 5 or 6 Fr sheath due to the small calibre of radial arteries. Simultaneous kissing stenting (SKS) technique requires a guiding catheter 7 Fr or larger and is therefore difficult to perform via transradial approach. Conversion to femoral approach or additional arterial access is usually required to achieve this goal. To overcome this limitation, a hydrophilic 7.5 Fr SheathLess guiding catheter can be exploited. This catheter possesses approximately the same size outer diameter as a 6 Fr sheath and an internal diameter of a 7.5 Fr catheter. A smooth and successful performance of SKS through transradial approach is described using this catheter. © 2009 Wiley‐Liss, Inc.  相似文献   
102.
103.
The anti-microbial compound triclosan is incorporated into numerous consumer products and is detectable in the urine of 75% of the general United States population. Recent epidemiological studies report positive associations with urinary triclosan levels and allergic disease. Although not sensitizing, earlier studies previously found that repeated topical application of triclosan augments the allergic response to ovalbumin (OVA) though a thymic stromal lymphopoietin (TSLP) pathway in mice. In the present study, early immunological effects following triclosan exposure were further evaluated following topical application in a murine model. These investigations revealed abundant expression of S100A8/A9, which reportedly acts as an endogenous ligand for Toll-like Receptor 4 (TLR4), in skin tissues and in infiltrating leukocytes during topical application of 0.75–3.0% triclosan. Expression of Tlr4 along with Tlr1, Tlr2 and Tlr6 increased in skin tissues over time with triclosan exposure; high levels of TLR4 were expressed on skin-infiltrating leukocytes. In vivo antibody blockade of the TLR4/MD-2 receptor complex impaired local inflammatory responses after four days, as evidenced by decreased Il6, Tnfα, S100a8, S100a9, Tlr1, Tlr2, Tlr4 and Tlr6 expression in the skin and decreased lymph node cellularity and production of IL-4 and IL-13 by lymph node T-cells. After nine days of triclosan exposure with TLR4/MD-2 blockade, impaired T-helper cell type 2 (TH2) cytokine responses were sustained, but other early effects on skin and lymph node cellularity were lost; this suggested alternative ligands/receptors compensated for the loss of TLR4 signaling. Taken together, these data suggest the S100A8/A9-TLR4 pathway plays an early role in augmenting immunomodulatory responses with triclosan exposure and support a role for the innate immune system in chemical adjuvancy.  相似文献   
104.
This paper describes a simple technique for the patterning of glia and neurons. The integration of neuronal patterning to Multi-Electrode Arrays (MEAs), planar patch clamp and silicon based ‘lab on a chip’ technologies necessitates the development of a microfabrication-compatible method, which will be reliable and easy to implement. In this study a highly consistent, straightforward and cost effective cell patterning scheme has been developed. It is based on two common ingredients: the polymer parylene-C and horse serum. Parylene-C is deposited and photo-lithographically patterned on silicon oxide (SiO2) surfaces. Subsequently, the patterns are activated via immersion in horse serum. Compared to non-activated controls, cells on the treated samples exhibited a significantly higher conformity to underlying parylene stripes. The immersion time of the patterns was reduced from 24 to 3 h without compromising the technique. X-ray photoelectron spectroscopy (XPS) analysis of parylene and SiO2 surfaces before and after immersion in horse serum and gel based eluant analysis suggests that the quantity and conformation of proteins on the parylene and SiO2 substrates might be responsible for inducing glial and neuronal patterning.  相似文献   
105.
106.
Pagetoid reticulosis is an indolent primary cutaneous T‐cell lymphoma. It typically presents as a solitary and slowly growing patch or plaque on the extremity, histologically characterized by an acanthotic epidermis infiltrated with atypical lymphocytes. Here, we present histological, immunophenotypical and molecular findings of a 29‐year‐old Jamaican man with bilateral wrist plaques. Histology showed marked acanthosis, hyperkeratosis and an intraepidermal infiltration consisting of large atypical lymphocytes. Immunohistochemical stains showed CD3 and CD5 positive T cells with significant loss of CD7, double negative CD4 and CD8 and strong positive CD30. Molecular analysis showed a monoclonal T‐cell receptor (TCR) gamma gene rearrangement. Review of the literature confirms that the immunophenotype of pagetoid reticulosis is variable with decreasing frequency of CD8+ cytotoxic/suppressor T cell, CD4+ helper T cell and least commonly CD4/CD8 double negative phenotypes. Although CD4/CD8 double negative phenotype appears to be associated with higher proliferation index, it does not appear to confer prognostic significance. Mourtzinos N, Puri PK, Guanghua W, Liu M‐L. CD4/CD8 double negative pagetoid reticulosis: a case report and literature review.  相似文献   
107.
Children are particularly vulnerable to the health effects of climate change, the biggest global health threat of the 21st century. However, the worst effects on child health can be avoided, and well‐designed climate policies can have important benefits for child health and equity. We call on child health professionals to seize opportunities to prevent climate change, improve child health and reduce inequalities, and suggest useful actions that can be taken.  相似文献   
108.
In October 2002, a series of sniper attacks in the Washington, DC area left 10 people dead and 3 wounded. We examined the association between identification with terrorist victims and psychological and behavioral outcomes. Participants were 1,238 residents of the Washington, DC area (ages 18–90 years; M = 41.73, SD = 12.56) who completed the Impact of Event Scale‐Revised, Patient Health Questionnaire‐9, and items pertaining to identification with attack victims approximately 3 weeks following the first sniper shooting. We examined 3 types of identification with the victims: (a) as like oneself, (b) as like a friend, and (c) as like a family member. The relationships of identification to posttraumatic stress and depressive symptoms were examined using linear regression analyses. Greater total identification was associated with more posttraumatic stress and depressive symptoms (B = 0.27, p < .001, and B = 0.44, p < .001, respectively), after adjusting for demographics. Those who specifically identified with the victims as either self (B = 0.24, p < .001), friend (B = 0.30, p < .001), or family member (B = 0.27, p < .001) reported more PTSD symptoms (n = 1,101). Identifying with victims as like a friend or family member, but not as like oneself, was associated with increased depressive symptoms (B = 0.61, p < .001, and B = 0.45, p = .01, respectively; n = 1,222). Presence and type of identification play a differential role in psychological and behavioral responses during traumatic events.  相似文献   
109.
110.
ObjectivesThe aim of this study was to evaluate the psychometric performance of the patient- and parent-reported measures in the International Consortium for Health Outcomes Measurement (ICHOM) Standard Set for Cleft Care, and to identify ways of improving concept coverage.MethodsData from 714 patients with cleft lip and/or palate, aged 8 to 9, 10 to 12.5, and 22 years were collected between November 2015 and April 2019 at Erasmus University Medical Center, Boston Children’s Hospital, Duke Children’s Hospital, and from participating sites in the CLEFT-Q Phase 3 study. The Standard Set includes 9 CLEFT-Q scales, the Nasal Obstruction Symptom Evaluation (NOSE) questionnaire, the Child Oral Health Impact Profile–Oral Symptoms Scale (COHIP-OSS), and the Intelligibility in Context Scale (ICS). Targeting, item-fit statistics, thresholds for item responses, and measurement precision (PSI) were analyzed using Rasch measurement theory.ResultsThe proportion of the sample to score within each instruments range of measurement varied from 69% (ICS) to 92% (CLEFT-Q teeth and COHIP-OSS). Specific problems with individual items within the NOSE and COHIP-OSS questionnaires were noted, such as poor item fit to the Rasch model and disordered thresholds (6 of 10). Reliability measured with PSI was above 0.82 for the ICS and all but one CLEFT-Q scale (speech distress). PSIs were lowest for the COHIP-OSS (0.43) and NOSE questionnaire (0.35).ConclusionThe patient- and parent-reported components within the facial appearance, psychosocial function, and speech domains are valid measures; however, the facial function and oral health domains are not sufficiently covered by the CLEFT-Q eating and drinking, NOSE, and COHIP-OSS, and these questionnaires may not be accurate enough to stratify cleft-related outcomes.  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