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   37970篇
  免费   3430篇
  国内免费   465篇
耳鼻咽喉   336篇
儿科学   2074篇
妇产科学   393篇
基础医学   4294篇
口腔科学   544篇
临床医学   3331篇
内科学   2678篇
皮肤病学   216篇
神经病学   15073篇
特种医学   364篇
外科学   1242篇
综合类   3160篇
现状与发展   3篇
一般理论   1篇
预防医学   3110篇
眼科学   136篇
药学   3147篇
  8篇
中国医学   1468篇
肿瘤学   287篇
  2024年   186篇
  2023年   927篇
  2022年   1407篇
  2021年   2042篇
  2020年   1894篇
  2019年   1766篇
  2018年   1615篇
  2017年   1730篇
  2016年   1773篇
  2015年   1543篇
  2014年   2552篇
  2013年   3487篇
  2012年   1977篇
  2011年   2402篇
  2010年   1847篇
  2009年   1817篇
  2008年   1885篇
  2007年   1716篇
  2006年   1388篇
  2005年   1185篇
  2004年   961篇
  2003年   868篇
  2002年   766篇
  2001年   548篇
  2000年   442篇
  1999年   364篇
  1998年   420篇
  1997年   337篇
  1996年   260篇
  1995年   219篇
  1994年   180篇
  1993年   166篇
  1992年   166篇
  1991年   162篇
  1990年   133篇
  1989年   127篇
  1988年   116篇
  1987年   89篇
  1986年   44篇
  1985年   80篇
  1984年   52篇
  1983年   35篇
  1982年   60篇
  1981年   27篇
  1980年   27篇
  1979年   19篇
  1978年   16篇
  1977年   15篇
  1976年   10篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
31.
Background:  Melatonin is gaining popularity as a sedative agent with children. This study sought to characterise this practice more precisely as well as examine aspects of its safety and efficacy in order to develop treatment guidelines.
Method:  Postal surveys of two groups of psychiatrists: generic child psychiatrists and psychiatrists who regularly treat learning disabled children.
Results:  Both groups (all of the specialists and 81% of the non-specialists) reported regular but not frequent use of melatonin in their usual practice, mostly for night-settling sleep problems refractory to behavioural modification strategies, commonly in the context of neurodevelopmental disability (especially autism). Treatment was described as being 'usually successful' and side-effects were highly infrequent and mild in nature. Variations in most prescribing practices were identified (dosage, timing).
Conclusions:  Melatonin appears to represent a useful and relatively safe drug when used in specific circumstances; however, the evidence-base underpinning its use, particularly over the long-term, remains modest. Thus caution and clinical audit of practice is required.  相似文献   
32.
目的 探讨待分类的精神病性和非精神病性精神障碍临床特征。方法 对待分类的精神病性和非精神病性精神障碍与精神分裂症临床资料进行对比分析。结果 待分类的精神病性障碍与精神分裂症在发病年龄、复发率、阳性家族史、治疗和疗效上无显著性差异;待分类的非精神病性精神障碍在复发率、阳性家族史及治愈率上与前两者有显著性差异。结论 待分类的精神病性障碍与精神分裂症可能具有同源性,部分非精神病性精神障碍与两者可能不同源。  相似文献   
33.
34.
Data are presented from the English national statistics for first admissions with affective disorders during the years 1982-1985. Overall rates per 10(5) of the population aged over 15 years were 36.1 for men and 59.1 for women. The peak incidence for depressive neurosis was middle adulthood, that for affective psychosis much later. The widowed and divorced showed much higher rates than the single and married for all types of disorder. Marriage appeared less protective for women than for men. The age-incidence relationship among the divorced and widowed was exaggerated for depressive neurosis and reversed for psychosis. The results are interpreted in terms of a (possibly biological) releasing effect of age upon affective psychosis that could be overwhelmed by severely adverse social circumstances. The findings support the validity of the distinction between affective psychoses and depressive neurosis.  相似文献   
35.
Serum and red blood cell folate in depression   总被引:2,自引:0,他引:2  
Serum folate concentrations were estimated in patients with major depressive disorders, lithium-treated patients, detoxified alcoholic patients and normal controls. Red blood cell (RBC) folate concentrations were also estimated in subgroups of patients with major depressive disorder and normal controls. Results showed significantly lower serum and RBC folate concentrations in patients with major depressive disorder than in normal controls. Lower serum folate concentrations were associated with greater severity of depression. There was no association between serum and RBC folate concentrations and endogenicity of depression or the presence of weight loss.  相似文献   
36.
Background Health-related quality of life (HRQL) is an accepted outcome measure in patients with mood and anxiety disorders. Yet, surprisingly little attention has been paid to the determinants. In this paper we test the hypothesis that it is associated with personality traits while controlling for mental disorders. Methods A large sample of outpatients (n=640) with mood and anxiety disorders was studied. The empirically supported five factor model of normal personality traits was assessed using the NEO-FFI and includes: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness. Mental disorders were assessed with the CIDI, and HRQL with the SF-36. Results Regression analyses revealed that the NEO-FFI scores, with the exception of conscientiousness, were significantly associated with SF-36 subscales and summary scores, independently from the mental disorders. The percentage of explained variance due to the personality traits was highest for the subscales Vitality (10.0%), Mental Health (13.3%) and the Mental Health Summary Score (9.5%). Furthermore, specific personality traits were related to specific SF-36 subscales. Conclusions A low HRQL of patients with mood or anxiety disorders is not only determined by the disease or the current health but is also shaped by personality traits that are relatively stable throughout an individual's life time.  相似文献   
37.
38.
BACKGROUND: Since 1997, a number of trials have shown promising results in treating generalized vitiligo with narrowband ultraviolet B (UVB) both in adults and children. However, there is little knowledge concerning the duration and permanency of the treatment-induced repigmentation. OBJECTIVE: Our main objective was to perform a follow-up trial of successfully treated patients receiving narrowband UVB for generalized vitiligo. METHODS: We have investigated to what degree the treatment-induced repigmentation remains stable for up to 2 years post-treatment. We performed an initial open trial including 31 patients with generalized vitiligo. They received narrowband UVB thrice weekly for up to 12 months. Patients experiencing > 75% repigmentation were defined responders and were included in the follow-up trial. Responders were followed every 6 months for up to 2 years after cessation of treatment. We observed the pigmentation status and registered any changes indicating loss of pigmentation and relapse. RESULTS: Eleven of the 31 treated patients were included in the follow-up trial. Six patients had relapse and five patients had stable response 24 months after cessation of treatment. Four out of six relapses were within 6 months post-treatment. CONCLUSION: In our study population of 31 patients with generalized vitiligo, five patients (16%) experienced > 75% stable repigmentation 2 years after cessation of a treatment programme of up to 1 years narrowband UVB therapy.  相似文献   
39.
Aim: This article reviews research centred around juvenile bipolar disorder with particular reference to diagnostic difficulties. Putative deficits are scrutinized with respect to trait likelihood and the roles of neuropsychology and neuroimaging in enhancing our understanding of juvenile bipolar disorder are discussed. Methods: Search terms including childhood, adolescent, youth and juvenile combined with the terms ‘bipolar disorder’, mania, depression and hypomania were used to identify relevant studies in MEDLINE and PsychLit. Results: Over recent years research into this relatively new disorder has increased phenomenally. Key issues within the field include diagnostic specificity, the heritability of the disorder, the impact of comorbidity and the implications of neuropsychological and neuroimaging findings. Conclusion: Despite concerning controversies in literature the diagnosis of bipolar disorder in children and adolescents as compared with adults, promising future research directions include better neurological characterization of the disorder through the application of findings from clinical populations, neuropsychological and neuroimaging research.  相似文献   
40.
BACKGROUND: Recent research has addressed the issue of subtyping juvenile bipolar disorder (JBD). Accordingly, we set out to find out, in a naturalistic sample of bipolar children and adolescents with mania and mixed mania, whether the most useful subtyping should be based on clinical features (elated vs. irritable) or course (episodic vs. chronic). METHODS: We studied 136 patients, 81 male patients (59.6%) and 55 female patients (40.4%), mean age 13.5 +/- 2.9 years, meeting the DSM-IV diagnosis of bipolar disorder, assessed by a structured clinical interview (Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version [K-SADS-PL]). RESULTS: Regarding course, 77 patients (56.6%) had an episodic course and 59 patients (43.4%) had a chronic course. Patients with chronic course were significantly younger, had an earlier onset of JBD, and presented a more frequent comorbidity with disruptive behavior disorders. According to the prevalent mood disturbance, 75 patients (55.1%) showed an elated and 61 patients (44.9%) showed an irritable mood. Elated mood was more frequent in patients with episodic course, whereas irritable mood was more frequent in the patients with chronic course. CONCLUSIONS: These findings suggest that chronic versus episodic course may be a putative differential feature. Further validation of such a distinction would require prospective studies, temperament evaluation, gender and neurobiologic approaches, and differential psychopharmacologic assignment and response.  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