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   1382篇
  免费   113篇
  国内免费   3篇
耳鼻咽喉   5篇
儿科学   29篇
妇产科学   22篇
基础医学   186篇
口腔科学   86篇
临床医学   188篇
内科学   251篇
皮肤病学   22篇
神经病学   139篇
特种医学   36篇
外科学   176篇
综合类   24篇
一般理论   3篇
预防医学   100篇
眼科学   47篇
药学   112篇
中国医学   24篇
肿瘤学   48篇
  2024年   2篇
  2023年   23篇
  2022年   56篇
  2021年   86篇
  2020年   61篇
  2019年   96篇
  2018年   102篇
  2017年   76篇
  2016年   56篇
  2015年   56篇
  2014年   63篇
  2013年   86篇
  2012年   127篇
  2011年   125篇
  2010年   74篇
  2009年   67篇
  2008年   85篇
  2007年   68篇
  2006年   41篇
  2005年   37篇
  2004年   28篇
  2003年   28篇
  2002年   10篇
  2001年   10篇
  2000年   11篇
  1999年   3篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1993年   1篇
  1992年   2篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1981年   1篇
  1978年   1篇
  1976年   2篇
  1975年   1篇
  1972年   1篇
排序方式: 共有1498条查询结果,搜索用时 15 毫秒
101.
102.
The low rate of understanding and the limited domain of attention are two important and distinctive characteristics of mental retardation. One of the important strategies to provide effective education for these subjects is to lessen the backgrounds and impacts of these affective factors. The aim of this research was to find the effect of computer games program on the amount of mentally retarded persons' attention. Sixty educable male mentally retarded subjects were selected from two 24-h care centres in Tehran. The Toulouse-Pieron Scale was used to determinate the subjects' attention at pre-post test. Members of the experimental group were subjected to 35 sets of computer games. After use of the sets of computer games, the attention scores of the subjects were assessed immediately after the intervention and 5 weeks later. The results showed that exactly after the intervention the average attention scores of the experimental group were significantly higher than those of the control group. But, 5 weeks after the intervention, there was actually no significant difference.  相似文献   
103.

Background

The nation-wide epidemiological survey of psychiatric disorders in term of lifetime prevalence is not adequately known in Iran. The prevalence of lifetime psychiatric disorders was estimated among the population of aged 18 and over on gender, age group, educational level, occupational status, marital status, and residential area.

Methods

The subjects were 25,180 individuals selected through a clustered random sampling method. The psychiatric disorders were diagnosed on the bases of Diagnostic and Statistical Manual of Mental Disorders-IV criteria. It is the first study in which the structured psychiatric interview administered to a representative sample of the Iranian population age 18 and over by the 250 trained clinical psychologist interviewers. The data was entered through EPI-Info software twice in an attempt to prevent any errors and SPSS-11 statistical software was also used for analyses. The odds ratios and their confidence intervals estimated by using logistic regression.

Results and Discussion

The prevalence of psychiatric disorders was 10.81%. It was more common among females than males (14.34% vs. 7.34%, P < 0.001). The prevalence of anxiety and mood disorders were 8.35% and 4.29% respectively. The prevalence of psychotic disorders was 0.89%; neuro-cognitive disorders, 2.78% and dissociative disorders, 0.77%. Among mood disorders, major depressive disorder (2.98%) and among anxiety disorders, phobic disorder (2.05%) had the higher prevalence. The prevalence of psychiatric disorders among divorced and separated 22.31%; residents of urban areas 11.77%; illiterates 13.80%; householders 15.48%; unemployed 12.33% that were more than other groups.

Conclusion

The mental health pattern in Iran is similar to the western countries, but it seems that the prevalence of psychiatric disorders in Iran may be lower than these countries.It is estimated that at least about 7 millions of Iranian population suffer from one or more of the psychiatric disorders. It shows the importance of the role of the psychiatric disorders in providing preventive and management programs in Iran.
  相似文献   
104.
Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia due to inactivating mutations in FGF23 or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). Herein we report a homozygous missense mutation (H193R) in the KLOTHO (KL) gene of a 13-year-old girl who presented with severe tumoral calcinosis with dural and carotid artery calcifications. This patient exhibited defects in mineral ion homeostasis with marked hyperphosphatemia and hypercalcemia as well as elevated serum levels of parathyroid hormone and FGF23. Mapping of H193R mutation onto the crystal structure of myrosinase, a plant homolog of KL, revealed that this histidine residue was at the base of the deep catalytic cleft and mutation of this histidine to arginine should destabilize the putative glycosidase domain (KL1) of KL, thereby attenuating production of membrane-bound and secreted KL. Indeed, compared with wild-type KL, expression and secretion of H193R KL were markedly reduced in vitro, resulting in diminished ability of FGF23 to signal via its cognate FGF receptors. Taken together, our findings provide what we believe to be the first evidence that loss-of-function mutations in human KL impair FGF23 bioactivity, underscoring the essential role of KL in FGF23-mediated phosphate and vitamin D homeostasis in humans.  相似文献   
105.
Attention-deficit hyperactivity disorder (ADHD) is a common disorder of childhood that affects 3-6% of school children. Conventional stimulant medications are recognized as useful symptomatic treatments by both specialists and parents. Nevertheless, approximately 30% of ADHD children treated with them do not respond adequately or cannot tolerate the associated adverse effects. Such difficulties highlight the need for alternative, safe and effective medications in the treatment of this disorder. Theophylline is a psychomotor stimulant most widely used as a broncodilator. Purinergic modulation may be therapeutically beneficial in the treatment of psychiatric disorders. We hypothesized that theophylline would be beneficial for the treatment of ADHD and report results of a trial of theophylline compared with methylphenidate for the treatment of ADHD. A total of 32 children with ADHD as defined by DSM IV were randomized to theophylline and methylphenidate dosed on an age and weight-adjusted basis at 4 mg/kg/day (under 12 years) and 3 mg/kg/day theophylline (over 12 years) (group 1) and 1 mg/kg/day methylphenidate (group 2) for a 6-week double-blind and randomized clinical trial. The principal measure of the outcome was the Teacher and Parent ADHD Rating Scale. Patients were assessed by a child psychiatrist, at baseline and at 14, 28 and 42 days after start of the medication. No significant differences were observed between theophylline and methylphenidate on the Parent and Teacher Rating Scale scores over the trial (t = 0.49, d.f. = 24 P = 0.62 and t = 0.19, d.f. = 24 P = 0.54 respectively). Although the number of dropouts in the methylphenidate group was higher than the theophylline group, there was no significant difference between the two protocols in terms of the dropouts. In addition, headaches were observed more often in the methylphenidate group. The results suggest that theophylline may be a useful for the treatment of ADHD. In addition, a tolerable side-effect profile is one of the advantages of theophylline in the treatment of ADHD. Nevertheless, our study is small and our results would need to be confirmed in a larger study.  相似文献   
106.
Objective: The aim of this study was to investigate electroencephalogram (EEG) dynamics using complexity analysis in children with attention-deficit/hyperactivity disorder (ADHD) compared with healthy control children when performing a cognitive task. Method: Thirty 7–12-year-old children meeting Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition (DSM–5) criteria for ADHD and 30 healthy control children underwent an EEG evaluation during a cognitive task, and Lempel–Ziv complexity (LZC) values were computed. There were no significant differences between ADHD and control groups on age and gender. Results: The mean LZC of the ADHD children was significantly larger than healthy children over the right anterior and right posterior regions during the cognitive performance. In the ADHD group, complexity of the right hemisphere was higher than that of the left hemisphere, but the complexity of the left hemisphere was higher than that of the right hemisphere in the normal group. Conclusion: Although fronto-striatal dysfunction is considered conclusive evidence for the pathophysiology of ADHD, our arithmetic mental task has provided evidence of structural and functional changes in the posterior regions and probably cerebellum in ADHD.  相似文献   
107.
The purpose of this study was to investigate the relationship among meta-cognitive beliefs, mindfulness and ruminative thoughts in post-secondary students. The Mindful Attention Awareness Scale (MAAS) and Ruminative Response Style Scale (RRS) were completed by 381 students who were selected using multi-stage cluster sampling from the Islamic Azad University of Bojnoord, Iran. The results showed a negative correlation between metacognitive beliefs and rumination (P < 0.01), while positive and significant correlation with mindfulness and ruminative thoughts (P < 0.01).  相似文献   
108.
109.
Growing evidence sheds light on the use of flavonoids as the promising alternatives for the treatment of chronic conditions, including cancer and neurodegenerative disorders. Accordingly, in the present study, we aimed at evaluating the effects of oral intake of two structurally different flavonoids 5-hydroxy-6,7,4?-trimethoxyflavone (flavone 1) and 5,7,4?-trihydroxyflavone (flavone 2) on recognition memory, hippocampal protein level of immediate early gene cFos and mitochondrial dynamic markers in Amyloid β (Aβ)-injected rats. Recognition aspect of memory and level of proteins were measured using novel object recognition test and Western blot, respectively. Our data indicated that even though flavone 1 was more effective than flavone 2 to prevent memory impairment, feeding with both flavones alleviated memory in Aβ-injected rats. Furthermore, in flavones-administered rats, mitochondrial dynamic balancing returned to the control level by the decline in Dynamin-related protein-1 protein level, a known marker for mitochondrial fission, and elevation in protein level of mitochondrial fusion factors Mitofusins 1 and 2. In parallel with behavior results, flavone 1 was more effectual on mitochondrial dynamic moderating. The more neuroprotective effects of flavone 1 could be attributed to its methylated structure leading to crossing of the blood-brain barrier with ease and metabolic stability and bioactivity.  相似文献   
110.
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