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   334篇
  免费   49篇
耳鼻咽喉   6篇
儿科学   18篇
妇产科学   9篇
基础医学   50篇
口腔科学   1篇
临床医学   42篇
内科学   61篇
皮肤病学   1篇
神经病学   41篇
特种医学   7篇
外科学   33篇
综合类   27篇
一般理论   7篇
预防医学   43篇
眼科学   3篇
药学   23篇
肿瘤学   11篇
  2023年   5篇
  2022年   6篇
  2021年   7篇
  2019年   6篇
  2018年   9篇
  2017年   4篇
  2016年   6篇
  2015年   6篇
  2014年   5篇
  2013年   11篇
  2012年   25篇
  2011年   24篇
  2010年   5篇
  2009年   16篇
  2008年   19篇
  2007年   28篇
  2006年   21篇
  2005年   25篇
  2004年   19篇
  2003年   13篇
  2002年   15篇
  2001年   10篇
  2000年   10篇
  1999年   11篇
  1995年   4篇
  1993年   1篇
  1992年   9篇
  1991年   9篇
  1990年   4篇
  1989年   9篇
  1988年   6篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1983年   2篇
  1981年   1篇
  1980年   2篇
  1977年   1篇
  1976年   1篇
  1974年   4篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1969年   2篇
  1967年   1篇
  1966年   1篇
  1963年   1篇
  1941年   1篇
  1939年   1篇
  1936年   3篇
排序方式: 共有383条查询结果,搜索用时 15 毫秒
1.
We describe a tarsorrhaphy technique whereby an ipsilateral upper-eyelid tarsal pillar is sutured to a corresponding lower-eyelid recipient site. This technique allows maintenance of a narrowed interpalpebral fissure indefinitely, yet is easy to reverse without incurring lid-margin damage. Additionally, the procedure can be adjusted postoperatively to either narrow or widen the initial surgical result. We report our combined surgical experience in 35 consecutive procedures using this technique to treat eyes with exposure-related keratopathy of varied etiology, including facial nerve palsies, combined facial nerve palsy and trigeminal neuropathy with an anesthetic cornea, Graves' disease, congenital craniofacial anomalies, and severe keratitis sicca syndrome. The procedure was successful in improving exposure keratopathy symptoms in all 35 cases. Complications, reflecting the authors' learning curve with this new procedure, included intermarginal pyogenic granulomas, stretching of the tarsal pillar, minor lower-eyelid-margin eversion, and tarsal pillar dehiscence.  相似文献   
2.
A prospective, randomized trial was performed to compare the incidence of wound infection following skin closure with subcuticular polyglycolic acid and interrupted monofilament nylon mattress sutures in patients undergoing high saphenous ligation (126 patients; 75 polyglycolic acid wounds, 86 interrupted monofilament nylon mattress wounds). By 6 weeks after operation, pus had discharged from 15 (20%) polyglycolic acid wounds compared with seven (8%) interrupted monofilament nylon mattress wounds (P = 0.05), giving an overall infection rate of 13.7%. Infection occurred in 23% of the 56 procedures performed by the two surgeons with the highest infection rates compared with 8% of the 105 procedures performed by the remaining nine surgeons (P = 0.02). The excess of infections in wounds closed with subcuticular polyglycolic acid was caused by an excess of infections in operations performed by the two surgeons with the highest infection rates. The higher infection rate found with subcuticular polyglycolic acid appeared to be operator dependent.  相似文献   
3.
4.
OBJECTIVES. The purpose of the study was to identify cases of hypervitaminosis D caused by the inadvertent overfortification of milk from a home-delivery dairy and to identify risk factors for this illness. METHODS. Hospital discharge, laboratory, and state health department data were used to define, identify, and describe cases of hypervitaminosis D diagnosed in the exposed communities between January 1, 1985, and June 30, 1991. To identify disease risk factors, community-based sex- and age-matched controls were used in a case-control study. RESULTS. Of the 56 case patients identified, at least 41 were hospitalized; 2 died. The study included 33 case patients and 93 control subjects. Nineteen of the 33 case patients had been customers of the implicated dairy. Risk of illness rose with increasing consumption of the dairy's milk and was also associated with vitamin D supplement use, sunburn susceptibility, and cancer history. Accounting for these factors did not alter the association between drinking the dairy's milk and developing hypervitaminosis D. CONCLUSIONS. Overfortification of milk with vitamin D can lead to hypervitaminosis D, manifested by severe illness and death. The episode highlights the need for monitoring the fortification process and enforcing the upper limit for vitamin D addition to milk.  相似文献   
5.
The question is explored of whether the state may stop competent individuals from being voluntarily euthanatized, now that the state's power is justified by reason instead of divine right. The challenge of determining a moral and political agenda which reason would endorse is analyzed in relation to the philosophical question: who may effectively constrain others so as to impose a particular view of the good life and the good death? And why? The right to euthanasia is established negatively in a pluralist, secular society not because we agree that it is good, but because where there is no justification for state authority to intervene coercively, individuals are morally free to act.  相似文献   
6.
AIDS and Behavior - South Africa maintains the world’s largest HIV prevalence, accounting for 20.4% of people living with HIV internationally. HIV Pre-exposure prophylaxis (PrEP) has...  相似文献   
7.
8.
9.
To identify neuroimaging biomarkers of alcohol dependence (AD) from structural magnetic resonance imaging, it may be useful to develop classification models that are explicitly generalizable to unseen sites and populations. This problem was explored in a mega-analysis of previously published datasets from 2,034 AD and comparison participants spanning 27 sites curated by the ENIGMA Addiction Working Group. Data were grouped into a training set used for internal validation including 1,652 participants (692 AD, 24 sites), and a test set used for external validation with 382 participants (146 AD, 3 sites). An exploratory data analysis was first conducted, followed by an evolutionary search based feature selection to site generalizable and high performing subsets of brain measurements. Exploratory data analysis revealed that inclusion of case- and control-only sites led to the inadvertent learning of site-effects. Cross validation methods that do not properly account for site can drastically overestimate results. Evolutionary-based feature selection leveraging leave-one-site-out cross-validation, to combat unintentional learning, identified cortical thickness in the left superior frontal gyrus and right lateral orbitofrontal cortex, cortical surface area in the right transverse temporal gyrus, and left putamen volume as final features. Ridge regression restricted to these features yielded a test-set area under the receiver operating characteristic curve of 0.768. These findings evaluate strategies for handling multi-site data with varied underlying class distributions and identify potential biomarkers for individuals with current AD.  相似文献   
10.
Major depressive disorder (MDD) is characterized by low mood for at least two weeks. Impaired emotion regulation has been suggested to be the consequence of dysfunctional serotonergic regulation of limbic and prefrontal regions, especially the amygdala, the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC). The impact of genetic variation on brain function can be investigated with intermediate phenotypes. A suggested intermediate phenotype of MDD is emotion recognition: The 5-HTTLPR polymorphism of SLC6A4 as well as other serotonergic genes have been associated with amygdala and prefrontal function during emotion recognition. Previously, it has been suggested that habituation is a more reliable index of emotion recognition than functional activation. We examined the relationship of genes involved in serotonergic signaling with amygdala as well as prefrontal functional activation and habituation during an emotion recognition task in 171 healthy subjects. While effects of 5-HTTLPR and of a serotonergic multi-marker score (5-HTTLPR, TPH1(rs1800532), TPH2(rs4570625), HTR1A(rs6295) and HTR2A(rs6311)) on amygdala activation did not withstand correction for multiple regions of interest, we observed a strong correlation of the multi-marker score and habituation in the amygdala, DLPFC, and ACC. We replicated a well-studied intermediate phenotype for association with 5-HTTLPR and provided additional evidence for polygenic involvement. Furthermore, we showed that task habituation may be influenced by genetic variation in serotonergic signaling, particularly by a serotonergic multi-marker score. We provided preliminary evidence that PFC activation is an important intermediate phenotype of MDD. Future studies are needed to corroborate the results in larger samples.  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