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   1069篇
  免费   107篇
耳鼻咽喉   4篇
儿科学   21篇
妇产科学   4篇
基础医学   195篇
口腔科学   13篇
临床医学   135篇
内科学   168篇
皮肤病学   3篇
神经病学   180篇
特种医学   32篇
外科学   113篇
综合类   16篇
一般理论   1篇
预防医学   88篇
眼科学   32篇
药学   145篇
中国医学   1篇
肿瘤学   25篇
  2023年   4篇
  2022年   18篇
  2021年   39篇
  2020年   23篇
  2019年   25篇
  2018年   26篇
  2017年   23篇
  2016年   23篇
  2015年   25篇
  2014年   44篇
  2013年   54篇
  2012年   85篇
  2011年   82篇
  2010年   36篇
  2009年   28篇
  2008年   61篇
  2007年   51篇
  2006年   62篇
  2005年   59篇
  2004年   52篇
  2003年   44篇
  2002年   51篇
  2001年   24篇
  2000年   15篇
  1999年   27篇
  1998年   17篇
  1997年   6篇
  1996年   14篇
  1995年   9篇
  1994年   10篇
  1993年   9篇
  1992年   9篇
  1991年   4篇
  1990年   11篇
  1989年   5篇
  1988年   7篇
  1987年   7篇
  1986年   3篇
  1985年   8篇
  1984年   5篇
  1983年   6篇
  1982年   8篇
  1981年   4篇
  1980年   8篇
  1979年   5篇
  1978年   3篇
  1975年   3篇
  1970年   4篇
  1969年   5篇
  1966年   6篇
排序方式: 共有1176条查询结果,搜索用时 31 毫秒
1.
2.
The effect of exogenous vascular endothelium growth factor (VEGF) on wound healing in an ischaemic skin flap model was evaluated in this study. Seventy-two Sprague-Dawley rats were used. Normal incisional wound and H-shaped double flaps were used as the wound models. The study was divided into two parts. In Part I, VEGF protein levels were determined from the incisional and H-shaped ischaemic wounds at 12 and 24 h, postoperatively. In Part II, tensile strength and immunohistochemical stains were examined to determine the level of microvessel density (MVD) at 1 and 2 weeks, postoperatively in simple incisional wounds, ischaemic wounds, and ischaemic wounds following 1 ml (1 microg/ml) exogenous VEGF injections into the subcutaneous tissue. The results showed a significantly higher level of VEGF protein in the ischaemic wounds than the incisional wounds. Tensile strength was statistically higher in the incisional wound group and in the ischaemic flap wounds with VEGF treatment compared to the ischaemic flaps with no treatment at 1 week, postoperatively (p>0.05). MVD data indicated that ischaemic wound repair with VEGF treatment had significantly higher MVD than the normal incisional wounds and ischaemic wounds without treatment. We conclude that exogenous application of VEGF can increase early angiogenesis and tensile strength in the ischaemic wound.  相似文献   
3.
Chromatic discrimination loss was evaluated with the Lanthony D-15 desaturated Panel among 89 workers professionally exposed to organic solvents and 114 non-exposed workers. Quantitative and qualitative analysis of the results reveal the following: among the non-exposed workers, the prevalence of tritanomalies and the mean colour confusion index increase with age; among the exposed workers, the prevalence of dyschromatopsia and the mean colour confusion index increase with age and with exposure level; for 4% of the moderately exposed workers and 26% of the highly exposed workers, protanomaly, deuteranomaly or scotopic loss were observed with the tritanomaly. Chromatic discrimination impairment may be an important indicator of neuro-ophthalmologic changes associated with professional exposure to organic solvents.  相似文献   
4.
Integrated surveillance of infectious multi-source diseases using a combination of epidemiology, ecology, genetics and evolution can provide a valuable risk-based approach for the control of important human pathogens. This includes a better understanding of transmission routes and the impact of human activities on the emergence of zoonoses. Until recently New Zealand had extraordinarily high and increasing rates of notified human campylobacteriosis, and our limited understanding of the source of these infections was hindering efforts to control this disease. Genetic and epidemiological modeling of a 3-year dataset comprising multilocus sequence typed isolates from human clinical cases, coupled with concurrent data on food and environmental sources, enabled us to estimate the relative importance of different sources of human disease. Our studies provided evidence that poultry was the leading cause of human campylobacteriosis in New Zealand, causing an estimated 58–76% of cases with widely varying contributions by individual poultry suppliers. These findings influenced national policy and, after the implementation of poultry industry-specific interventions, a dramatic decline in human notified cases was observed in 2008. The comparative-modeling and molecular sentinel surveillance approach proposed in this study provides new opportunities for the management of zoonotic diseases.  相似文献   
5.
If an individual's gas exchange threshold (GET) is measured on several separate occasions, without a change in aerobic fitness, a random variability will be observed. However, it is not known how much of this variability is biologically determined and how much results from variability in the calibration and measurement processes. The statistical re-sampling technique of Bootstrapping was used to estimate the variability of the GET on a single occasion. This analysis provides the first estimate of the combined contribution of breath-by-breath measurement and calibration processes (6%), to the total between-occasion random variability, leaving biological variability to account for the remainder of the imprecision in the measurement of the GET.  相似文献   
6.
Genetic testing in a multisite clinical trial network for inherited eye conditions is described in this retrospective review of data collected through eyeGENE®, the National Ophthalmic Disease Genotyping and Phenotyping Network. Participants in eyeGENE were enrolled through a network of clinical providers throughout the United States and Canada. Blood samples and clinical data were collected to establish a phenotype:genotype database, biorepository, and patient registry. Data and samples are available for research use, and participants are provided results of clinical genetic testing. eyeGENE utilized a unique, distributed clinical trial design to enroll 6,403 participants from 5,385 families diagnosed with over 30 different inherited eye conditions. The most common diagnoses given for participants were retinitis pigmentosa (RP), Stargardt disease, and choroideremia. Pathogenic variants were most frequently reported in ABCA4 (37%), USH2A (7%), RPGR (6%), CHM (5%), and PRPH2 (3%). Among the 5,552 participants with genetic testing, at least one pathogenic or likely pathogenic variant was observed in 3,448 participants (62.1%), and variants of uncertain significance in 1,712 participants (30.8%). Ten genes represent 68% of all pathogenic and likely pathogenic variants in eyeGENE. Cross‐referencing current gene therapy clinical trials, over a thousand participants may be eligible, based on pathogenic variants in genes targeted by those therapies. This article is the first summary of genetic testing from thousands of participants tested through eyeGENE, including reports from 5,552 individuals. eyeGENE provides a launching point for inherited eye research, connects researchers with potential future study participants, and provides a valuable resource to the vision community.  相似文献   
7.
Microarray-based comparative genomic hybridization (CGH) provides a powerful tool for whole genome analyses and the rapid detection of genomic variation that underlies virulence and disease. In the field of Plasmodium research, many of the parasite genomes that one might wish to study in a high throughput manner are not laboratory clones, but clinical isolates. One of the key limitations to the use of clinical samples in CGH, however, is the miniscule amounts of genomic DNA available. Here we describe the successful application of multiple displacement amplification (MDA), a non-PCR-based amplification method that exhibits clear advantages over all other currently available methods. Using MDA, CGH was performed on a panel of NF54 and IT/FCR3 clones, identifying previously published deletions on chromosomes 2 and 9 as well as polymorphism in genes associated with disease pathology.  相似文献   
8.
The present study investigated sex differences and the effect of a high level of estradiol in the female meadow vole on performance in the forced swim test (FST) and the Morris water maze in meadow voles. Female meadow voles were ovariectomized (OVX) and administered either vehicle (sesame oil) or estradiol for 2 days prior to performing the FST. Four days following the FST, all animals were run in the Morris water maze. Results indicated that estradiol-injected female meadow voles showed more 'depressive-like' behaviors in the FST (greater time spent immobile and less time spent swimming) than vehicle-treated female or male meadow voles. In addition, estradiol-treated females had impaired performance (greater latencies and distance swam to reach the hidden platform) than both vehicle-treated female and male meadow voles, consistent with previous data. Despite the fact that estradiol administration increased 'depressive-like' behaviors in the FST and impaired performance in the Morris water maze, there was no correlation between the two behaviors indicating that 'depressive-like' behaviors did not account for the differences seen in spatial performance in the Morris water maze. To our knowledge, this is the first demonstration in rodents indicating that estradiol-mediated changes in behavior in the FST is not indicative of subsequent performance in the Morris water maze.  相似文献   
9.
Archives of Sexual Behavior - Gender variance is a broad term used to describe gender non-conforming behaviors. Past studies have used the parental response to Child Behavior Checklist (CBCL) Item...  相似文献   
10.
There is a marked variability in the susceptibility of different cell types in the nervous system to toxic insult. Some of this variation is associated with factors related to the specific functions of the cells, but some also reflects genetic differences in metabolism. It is important that the role of genetic polymorphisms are considered, along with the broader aspects of susceptibility to neurotoxins, in the development of certain neurological disorders.  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