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   466000篇
  免费   24331篇
  国内免费   1631篇
耳鼻咽喉   5870篇
儿科学   14481篇
妇产科学   10972篇
基础医学   60489篇
口腔科学   10542篇
临床医学   42606篇
内科学   92983篇
皮肤病学   8298篇
神经病学   37862篇
特种医学   19989篇
外国民族医学   108篇
外科学   70949篇
综合类   4836篇
一般理论   340篇
预防医学   39332篇
眼科学   11230篇
药学   31884篇
  8篇
中国医学   528篇
肿瘤学   28655篇
  2022年   2986篇
  2021年   6540篇
  2020年   3923篇
  2019年   6211篇
  2018年   10179篇
  2017年   8751篇
  2016年   8601篇
  2015年   11252篇
  2014年   13652篇
  2013年   16267篇
  2012年   29268篇
  2011年   25280篇
  2010年   13641篇
  2009年   13917篇
  2008年   19771篇
  2007年   21343篇
  2006年   21399篇
  2005年   28955篇
  2004年   29282篇
  2003年   23723篇
  2002年   18100篇
  2001年   6715篇
  2000年   3492篇
  1999年   8383篇
  1998年   3715篇
  1997年   2946篇
  1996年   2676篇
  1995年   2560篇
  1992年   8305篇
  1991年   8418篇
  1990年   8535篇
  1989年   8118篇
  1988年   7606篇
  1987年   7368篇
  1986年   7087篇
  1985年   6385篇
  1984年   4971篇
  1983年   4208篇
  1982年   2489篇
  1979年   4677篇
  1978年   3231篇
  1977年   2514篇
  1975年   3023篇
  1974年   3659篇
  1973年   3222篇
  1972年   3187篇
  1971年   3086篇
  1970年   2878篇
  1969年   2694篇
  1968年   2407篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
32.
The present narrative review examines the scientific evidence of the biological mechanisms that may link periodontitis and diabetes, as a source of comorbidity. Publications regarding periodontitis and diabetes, in human, animals, and in vitro were screened for their relevance. Periodontal microbiome studies indicate a possible association between altered glucose metabolism in prediabetes and diabetes and changes in the periodontal microbiome. Coinciding with this, hyperglycemia enhances expression of pathogen receptors, which enhance host response to the dysbiotic microbiome. Hyperglycemia also promotes pro-inflammatory response independently or via the advanced glycation end product/receptor for advanced glycation end product pathway. These processes excite cellular tissue destruction functions, which further enhance pro-inflammatory cytokines expression and alteration in the RANKL/osteoprotegerin ratio, promoting formation and activation of osteoclasts. The evidence supports the role of several pathogenic mechanisms in the path of true causal comorbidity between poorly controlled diabetes and periodontitis. However, further research is needed to better understand these mechanisms and to explore other mechanisms.  相似文献   
33.
34.
Bowel diseases of prematurity, including necrotizing enterocolitis, are dreaded ailments of neonates. Early diagnosis is difficult, with clinical and radiographic findings often inconclusive. We present a novel use of contrast-enhanced ultrasound in detection of pediatric bowel disease. Early identification of compromised blood flow or an at-risk bowel can be quantitatively detected and monitored. This ability has implications for guidance of emerging therapies, allowing targeting of inflammation. These findings represent an advancement in detection of bowel disease in neonates.  相似文献   
35.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.  相似文献   
36.
37.
38.
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period.  相似文献   
39.
40.
Geneticists have, for years, understood the nature of genome‐wide association studies using common genomic variants. Recently, however, focus has shifted to the analysis of rare variants. This presents potential problems for researchers, as rare variants do not always behave in the same way common variants do, sometimes rendering decades of solid intuition moot. In this paper, we present examples of the differences between common and rare variants. We show why one must be significantly more careful about the origin of rare variants, and how failing to do so can lead to highly inflated type I error. We then explain how to best avoid such concerns with careful understanding and study design. Additionally, we demonstrate that a seemingly low error rate in next‐generation sequencing can dramatically impact the false‐positive rate for rare variants. This is due to the fact that rare variants are, by definition, seen infrequently, making it hard to distinguish between errors and real variants. Compounding this problem is the fact that the proportion of errors is likely to get worse, not better, with increasing sample size. One cannot simply scale their way up in order to solve this problem. Understanding these potential pitfalls is a key step in successfully identifying true associations between rare variants and diseases.  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