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   354篇
  免费   28篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   26篇
妇产科学   3篇
基础医学   39篇
口腔科学   30篇
临床医学   40篇
内科学   63篇
皮肤病学   5篇
神经病学   15篇
特种医学   62篇
外科学   28篇
综合类   28篇
预防医学   17篇
药学   6篇
中国医学   4篇
肿瘤学   20篇
  2023年   1篇
  2022年   1篇
  2021年   10篇
  2020年   3篇
  2019年   4篇
  2018年   4篇
  2017年   6篇
  2016年   6篇
  2015年   10篇
  2014年   6篇
  2013年   18篇
  2012年   18篇
  2011年   14篇
  2010年   25篇
  2009年   12篇
  2008年   9篇
  2007年   6篇
  2006年   9篇
  2005年   8篇
  2004年   3篇
  2003年   3篇
  2002年   2篇
  2001年   2篇
  2000年   6篇
  1999年   3篇
  1998年   24篇
  1997年   14篇
  1996年   19篇
  1995年   8篇
  1994年   13篇
  1993年   9篇
  1992年   3篇
  1991年   9篇
  1990年   5篇
  1989年   11篇
  1988年   12篇
  1987年   15篇
  1986年   10篇
  1985年   6篇
  1984年   6篇
  1983年   3篇
  1982年   8篇
  1981年   2篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1976年   7篇
  1975年   2篇
  1971年   2篇
排序方式: 共有387条查询结果,搜索用时 31 毫秒
91.
目的 研究唇腭裂患者AF-BF距和AXB角.方法 选取20例替牙期及30例恒牙期唇腭裂患者拍摄头颅定位侧位X线片,测量其AF-BF距及AXB角与北京市同龄、同性别正常儿童、青少年的AF-BF距及AXB角值进行比较.结果 替牙期和恒牙期唇腭裂患者AF-BF距及AXB角值无性别差异(P > 0.05).新疆地区替牙期和恒牙期唇腭裂患者AF-BF距小于北京市正常儿童、青少年(P < 0.05),而AXB角值差异无统计学意义(P > 0.05).结论 AF-BF距可以作为评价唇腭裂患者上下颌骨间矢状关系的指标之一,但最好进行综合分析.  相似文献   
92.
不育患者精索静脉曲张手术前后精液质量变化的观察   总被引:1,自引:0,他引:1  
目的:观察不育患者精索静脉曲张手术前后精液质量的变化,探讨手术的价值。方法:按WHO标准常规分析110例不育伴精索静脉曲张患者手术前后的精液质量。结果:110例精索静脉曲张患者术后精子密度、(A+B)级精子比率、有效精子数、精子活动率、活动精子数、精子低渗肿胀比率、正常形态精子比率较术前明显提高,两组差别有显著性意义(P0.05)。结论:精索静脉曲张手术能改善精液的质量。  相似文献   
93.
本文论述了分子筛制氧机的工作原理、主要组成部分及作用.强调了应严格遵守规章制度,认真做好制氧机的维护保养,加强质量监控和管理.同时阐述了医院在选购制氧系统时要综合分析影响其能耗的因素,在保证氧气产量和纯度的前提下,尽量降低系统能耗,提高长期运行的经济效益.  相似文献   
94.
BACKGROUND: One of the most recognizable features of psychopathy is the reduced ability to successfully learn and adapt overt behavior. This might be due to deficient processing of error information indicating the need to adapt controlled behavior. METHODS: Event-related potentials (ERPs) and behavioral components of error-monitoring processes were investigated in 16 individuals with psychopathy and in 18 healthy subjects. A letter version of the Eriksen flanker task was used in two conditions. The first condition (normal condition) required participants to press one of two buttons depending on the identity of the target stimulus. The second condition (signaling condition) required them to signal each time they had committed an error by making a second press on a signaling button. Early stages of error monitoring were investigated by using the error-related negativity (ERN/Ne) and post-error slowing as indexes. Later stages were explored by examining the error positivity (Pe) and signaling rates. RESULTS: Both groups showed similar ERN amplitudes and amounts of post-error slowing. The psychopathic group exhibited both reduced Pe amplitudes and diminished error-signaling rates compared with the control group. CONCLUSIONS: Individuals with psychopathy show intact early error processing and automatic behavioral adaptation but have deficits in later stages of error processing and controlled behavioral adaptation. This is an indication that individuals with psychopathy are unable to effectively use error information to change their behavior adequately.  相似文献   
95.
Hyperinsulinaemia/euglycaemia therapy (HIET) consists of the infusion of high-dose regular insulin (usually 0.5 to 1 IU/kg per hour) combined with glucose to maintain euglycaemia. HIET has been proposed as an adjunctive approach in the management of overdose of calcium-channel blockers (CCBs). Indeed, experimental data and clinical experience, although limited, suggest that it could be superior to conventional pharmacological treatments including calcium salts, adrenaline (epinephrine) or glucagon. This paper reviews the patho-physiological principles underlying HIET. Insulin administration seems to allow the switch of the cell metabolism from fatty acids to carbohydrates that is required in stress conditions, especially in the myocardium and vascular smooth muscle, resulting in an improvement in cardiac contractility and restored peripheral resistances. Studies in experimental verapamil poisoning in dogs have shown that HIET significantly improves metabolism, haemodynamics and survival in comparison with conventional therapies. Clinical experience currently consists only of a few isolated cases or short series in which the administration of HIET substantially improved cardiovascular conditions in life-threatening CCB poisonings, allowing the progressive discontinuation of vasoactive agents. While we await further well-designed clinical trials, some rational recommendations are made about the use of HIET in severe CBB overdose. Although the mechanism of action is less well understood in this condition, some experimental data suggesting a potential benefit of HIET in β-adrenergic blocker toxicity are discussed; clinical data are currently lacking.  相似文献   
96.
Pityriasis versicolor is a common superficial mycoses of the skin. It is now recognized that the causative organisms of this infection are different species of Malassezia . The aim of this study was to determine the distribution of Malassezia species in patients with pityriasis versicolor in Adana, Turkey. In total, 97 patients positive for Malassezia elements, namely, yeast cells and short hyphae in microscopic examination, were included in the study. All samples were inoculated in plates containing modified Dixon's medium. However, only 44 of the patients (45.4%) showed Malassezia spp. in culture. Malassezia globosa (47.7%) was the most commonly isolated species followed by Malassezia furfur (36.4%) and Malassezia slooffiae (15.9%). Mixed Malassezia species were not isolated. In conclusion, M. globosa was found to be the predominant PV isolate in Adana, Turkey.  相似文献   
97.
Specimens of excised tissue from the porta hepatis in 26 infants with extrahepatic biliary atresia undergoing hepatic portoenterostomy were analysed histologically for the presence and size of biliary ductules. No correlation could be found between the establishment of effective biliary drainage and the number or size of biliary ductules. it is suggested that prognosis after surgery may be related to the intrahepatic lesion and age of the child at operation rather than to the histology of the extrahepatic bile duct remnants.  相似文献   
98.
The response of bronchiolitis to bronchodilator drugs is controversial. The present study was designed to evaluate the efficacy of oral or metered dose inhaler (MDI) salbutamol using a coffee cup as a spacer device in bronchiolitis. In the trial, 31 hospitalized patients between 6 and 24 months of age, who exhibited the first episode of acute bronchiolitis without any other predisposing illness such as cystic fibrosis, congenital heart disease etc., were randomly assigned to receive oral salbutamol (n=11, 0.1 mg/kg per dose, four times a day), or MDI salbutamol (n = 12, 200 μg per dose, every 3 h) or formed the control group without any bronchodilator therapy (n = 8). All of the patients were given supplemental oxygen as needed and adequate hydration was maintained. The patients were evaluated with clinical symptom scores. There were no differences in the beneficial or side effects of salbutamol, or the number of days in hospital between the treatment groups and the control group. It was concluded that there is no beneficial effect in using bronchodilators in infants with bronchiolitis. Supplemental oxygen and maintenance of normal hydration may be adequate.  相似文献   
99.
Analysis of newly identified microsatellite polymorphisms flanking the low density lipoprotein receptor (LDLR) gene was undertaken in the kindred of a child with apparent homozygous LDLR deficiency. The applicability of these approaches to prenatal diagnosis is considered and compared with previous approaches applying functional studies of the LDLR in amniotic fibroblasts.  相似文献   
100.
In this randomized crossover trial we investigated whether the use of controlled ovarian hyperstimulation with low-dose human menopausal gonadotrophin in couples with male subfertility leads to a higher probability of conception when intrauterine insemination (IUI) is applied. We also investigated whether the efficacy of IUI in natural or stimulated cycles was related to the severity of male subfertility. Seventy-four couples completed 308 treatment cycles. Thirteen pregnancies occurred after IUI in a natural cycle (pregnancy rate per completed cycle: 8.4%) and 21 after IUI in a stimulated cycle (pregnancy rate per completed cycle: 13.7%). The difference between the two treatment modalities was not statistically significant. The efficacy of IUI in stimulated cycles was related to the severity of the semen defect. In couples with a total motile sperm count < 10 x 10(6), ovarian stimulation did not improve treatment outcome, while it did in couples with a total motile sperm count > or = 10 x 10(6). Compared with the expected chance of conceiving spontaneously without treatment, both natural and stimulated cycles improved the probability of conception. We conclude that, for the group as a whole, ovarian stimulation did not improve the probability of conception. However, in couples with less severe semen defects, ovarian stimulation did improve the probability of conception.   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