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   16454篇
  免费   1308篇
  国内免费   54篇
耳鼻咽喉   221篇
儿科学   363篇
妇产科学   228篇
基础医学   2039篇
口腔科学   630篇
临床医学   1636篇
内科学   3673篇
皮肤病学   211篇
神经病学   1271篇
特种医学   685篇
外科学   2490篇
综合类   331篇
一般理论   17篇
预防医学   1281篇
眼科学   512篇
药学   1124篇
中国医学   40篇
肿瘤学   1064篇
  2021年   201篇
  2020年   104篇
  2019年   205篇
  2018年   232篇
  2017年   181篇
  2016年   226篇
  2015年   278篇
  2014年   420篇
  2013年   690篇
  2012年   865篇
  2011年   947篇
  2010年   503篇
  2009年   491篇
  2008年   925篇
  2007年   1040篇
  2006年   1060篇
  2005年   1046篇
  2004年   1111篇
  2003年   1020篇
  2002年   1032篇
  2001年   183篇
  2000年   144篇
  1999年   215篇
  1998年   240篇
  1997年   213篇
  1996年   196篇
  1995年   203篇
  1994年   154篇
  1993年   164篇
  1992年   115篇
  1991年   124篇
  1990年   128篇
  1989年   123篇
  1988年   133篇
  1987年   106篇
  1986年   105篇
  1985年   134篇
  1984年   186篇
  1983年   164篇
  1982年   222篇
  1981年   231篇
  1980年   173篇
  1979年   109篇
  1978年   120篇
  1977年   143篇
  1976年   139篇
  1975年   128篇
  1974年   106篇
  1973年   106篇
  1972年   76篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Capillary malformation–arteriovenous malformation syndrome (CM‐AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM‐AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM‐AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM‐AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.  相似文献   
4.
Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence.  相似文献   
5.
Abstract

Purpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.

Design: Secondary analysis of data collected from a clinical trial.

Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.

Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.

Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.

Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI.  相似文献   
6.
7.
8.
BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group.  相似文献   
9.
10.
BACKGROUND: Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. METHODS: Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. RESULTS: Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 +/- 0.9 vs 3.21 +/- 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 +/- 2.9 vs 2.37 +/- 2.9 mm(2), p = 0.004) and total vessel area (18.36 +/- 5.8 vs 12.81 +/- 4.8 mm(2), p = 0.012) than those with normal plasma concentrations. CONCLUSIONS: Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation.  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