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   8259篇
  免费   893篇
  国内免费   11篇
耳鼻咽喉   119篇
儿科学   265篇
妇产科学   424篇
基础医学   1366篇
口腔科学   146篇
临床医学   992篇
内科学   1461篇
皮肤病学   122篇
神经病学   763篇
特种医学   330篇
外科学   861篇
综合类   233篇
一般理论   11篇
预防医学   786篇
眼科学   161篇
药学   535篇
中国医学   9篇
肿瘤学   579篇
  2021年   114篇
  2020年   100篇
  2019年   109篇
  2018年   148篇
  2017年   88篇
  2016年   135篇
  2015年   122篇
  2014年   186篇
  2013年   269篇
  2012年   392篇
  2011年   431篇
  2010年   214篇
  2009年   201篇
  2008年   374篇
  2007年   346篇
  2006年   351篇
  2005年   372篇
  2004年   378篇
  2003年   328篇
  2002年   334篇
  2001年   286篇
  2000年   299篇
  1999年   252篇
  1998年   103篇
  1997年   93篇
  1996年   92篇
  1995年   106篇
  1994年   107篇
  1993年   86篇
  1992年   201篇
  1991年   180篇
  1990年   195篇
  1989年   188篇
  1988年   178篇
  1987年   147篇
  1986年   136篇
  1985年   113篇
  1984年   118篇
  1983年   81篇
  1982年   63篇
  1981年   53篇
  1980年   63篇
  1979年   118篇
  1978年   90篇
  1977年   65篇
  1976年   71篇
  1975年   56篇
  1974年   81篇
  1973年   59篇
  1972年   68篇
排序方式: 共有9163条查询结果,搜索用时 390 毫秒
51.
52.
预测哪些人可能因急性发病而需要急诊入院,已成为英国国家医疗卫生服务体系(NHS)的一个重要话题。卫生部门将那些患有复杂的慢性疾病,经常不定期地去二级医疗机构就医的人们视为高危人群。确定这些人之后,社区护理员或其他卫生人员将通过“个案管理”的方法照顾他们。“个案管理”此前被定义为“对疾病尚未控制或所需费用昂贵的患者进行加强医疗计划”。社区护理人员可来自任何护理部门,但一般认为社区护士更能胜任这一角色。此方法能够减少可避免的急诊入院患者数量,并有助于实现到2008年3月减少5%急诊住院床位日的公共医疗服务目标。但是,如何才能界定需要急诊入院的高危人群呢?  相似文献   
53.
Detailed analyses of the neuropathologic changes in the cerebralcortex of elderly individuals and Alzheimer's disease patientshave demonstrated that certain components of the neocorticaland hippocampal circuits are likely to be selectively vulnerable.Based on the distribution of neurofibrillary tangles (NFTs)and senile plaques, it has been proposed that a global cortico-corticaldisconnection leads to the loss of integrated functions observedin Alzheimer's disease. In order to investigate the distributionof lesions associated with aging as well as with the earliestsymptoms of senile dementia, we performed a quantitative neuropathologicavaluation of a large series of elderly patients representingthe entire autopsy population for the year 1989 from a geriatrichospital. Among the 145 cases quantitatively assessed, therewere 102 nondemented patients, 33 patients presenting clinicallywith globally intact intellectual function but early signs ofimpairment of specific cognitive functions, and 10 cases withsenile dementia of the Alzheimer type. All of the cases hadNFTs in layer II of the entorhinal cortex, regardless of theirclinical diagnosis, and most cases had some NFTs in the CA1field of the hippocampus. Severe pathologic changes within theinferior temporal neocortex were observed only in the dementedcases. The extent of amyloid deposition was not correlated withthe clinical diagnosis and seemed to be present in the neocorticalareas earlier than in the hippocampal formation. Also, severalcases contained NFTs without amyloid deposition, but amyloidnever occurred without NFTs. These results suggests that involvementof certain structures within the hippocampal formation is aconsistent feature of aging. Thus, involvement of the hippocampalformation may be a necessary, but not sufficient, conditionfor the clinical expression of dementia, which is likely tobe more closely related to the progressive degeneration of selectneuronal populations in the neocortex.  相似文献   
54.
BACKGROUND: Risperidone has been shown to be clinically effective for the treatment of aggressive behavior in children, yet no information is available regarding whether risperidone exhibits aggression-specific suppression in preclinical studies that use validated developmentally immature animal models of escalated aggression. Previously, we have shown that exposure to low doses of the psychostimulant cocaine-hydrochloride (.5 mg/kg intraperitoneally) during the majority of pubertal development (postnatal days [P]27-57) generates animals that exhibit a high level of offensive aggression. This study examined whether risperidone exerts selective aggression-suppressing effects by using this pharmacologic animal model of highly escalated offensive aggression. METHODS: Experimental hamsters were tested for offensive aggression after the acute administration of risperidone (.05-1.0 mg/kg, intraperitoneally). RESULTS: Risperidone dose-dependently reduced the highly aggressive phenotype, with a significant reduction observed at .1-.2 mg/kg for most aggressive responses measured. Experimental animals treated with higher doses of risperidone (.3-1.0 mg/kg) showed significant reductions in aggression and social interest toward intruders, indicating more general behavioral inhibition. CONCLUSIONS: These studies provide evidence that risperidone exerts specific aggression-suppressing effects in a developmentally immature animal model of escalated aggression.  相似文献   
55.
A stretcher for transporting the injured is described which in an almost automatic fashion immobilizes and places in controlled traction and countertraction any long bone fracture. At the same time vertebral fractures are placed in sufficient hypertension to protect the cord and prevent increase in deformity.There is no necessity for the first aid crew to make a diagnosis as there is only one way to position the patient regardless of the injury.X-rays may be taken without taking the patient out of the stretcher.  相似文献   
56.
This study assesses the effects of HIV (human immunodeficiency virus) antibody testing on subsequent (one year) sexual behavior among 270 homosexual men at a Boston community health center, 21 per cent of whom were unaware of their test result. Except for the number of steady partners, the levels of all sexual activities of all groups of study participants declined over time. No effects of test awareness of antibody status were found on protective behavior for receptive anogenital contact. Elimination of unprotected insertive anogenital contact (by elimination of the practice or by condom use) was reported somewhat more often among seropositive men who became aware of their test result. Increased negative emotional reactions were reported by HIV seropositive men who were aware of their test result. These results suggest some behavioral impact of HIV antibody test knowledge in this cohort, but may not be generalizable to other populations.  相似文献   
57.
Between 1974 and 1984, 173 patients were treated for squamous cell carcinoma of the tongue base. Fifty-four patients had T1 or T2 primaries, while 115 patients had T3 or T4 tumors (4 were not staged). Lymph node metastasis was present in 120 patients. Early primary tumors treated with surgery or radiotherapy had a control rate of 83% (5 of 6 tumors) and 89% (40 of 45 tumors), respectively. For advanced primary tumors, definitive radiotherapy produced a local control rate of 55% (42 of 76 tumors), compared with 79% (23 of 29 tumors) for surgery and postoperative radiotherapy. If primary control was obtained, the regional failure rate was less than 10%. Tumor growth patterns were predictive of the response to radiotherapy. The primary control rate at 2 years for 21 patients with exophytic tumors was 84% as opposed to 58% for 62 patients with ulcerative-infiltrative tumors (p = 0.04). Radiotherapy is effective for early stage or exophytic tumors, whereas for advanced or deeply invasive tumors combined therapy enhances local control.  相似文献   
58.
59.
60.
Sixteen chronic asthmatic patients inadequately controlled by drugs had, after one year of hypnotherapy, a fall in admissions from 44 in the year before starting therapy to 13 in the year after. Duration of stay was reduced for 13 patients by 249 days; prednisolone was withdrawn in 6, reduced in 8 and increased in none. Side effects of drugs were reduced. Although 62% reported improvement on a visual analogue scale, observations of air flow gave variable results.  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