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   13848篇
  免费   890篇
  国内免费   11篇
耳鼻咽喉   382篇
儿科学   454篇
妇产科学   775篇
基础医学   1498篇
口腔科学   257篇
临床医学   1273篇
内科学   2475篇
皮肤病学   414篇
神经病学   942篇
特种医学   805篇
外科学   2692篇
综合类   247篇
一般理论   11篇
预防医学   931篇
眼科学   402篇
药学   446篇
中国医学   6篇
肿瘤学   739篇
  2021年   95篇
  2020年   82篇
  2019年   88篇
  2018年   137篇
  2017年   85篇
  2016年   145篇
  2015年   590篇
  2014年   703篇
  2013年   777篇
  2012年   880篇
  2011年   885篇
  2010年   763篇
  2009年   713篇
  2008年   884篇
  2007年   771篇
  2006年   759篇
  2005年   703篇
  2004年   583篇
  2003年   324篇
  2002年   278篇
  2001年   276篇
  2000年   283篇
  1999年   252篇
  1998年   117篇
  1997年   117篇
  1996年   117篇
  1995年   123篇
  1994年   119篇
  1993年   105篇
  1992年   206篇
  1991年   182篇
  1990年   202篇
  1989年   199篇
  1988年   183篇
  1987年   157篇
  1986年   137篇
  1985年   119篇
  1984年   128篇
  1983年   108篇
  1982年   88篇
  1981年   79篇
  1980年   85篇
  1979年   137篇
  1978年   93篇
  1977年   72篇
  1976年   78篇
  1975年   65篇
  1974年   87篇
  1973年   66篇
  1972年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
At birth the human newborn is immature and has not yet acquired fully competent organ functions. During lactation especially the digestive tract and the immune system gain competence. Lactation is regulated by a complex interaction of numerous hormonal factors. Most important are probably prolactin and oxytocin—two hormones produced and secreted in the pituitary. The production and secretion of these two hormones is again regulated by several factors in the central nervous system and these mechanisms can be disturbed by a variety of exogenous factors such as drugs and any other substances interacting with dopamine metabolism in the brain. It is important to know these physiological interactions to be able to understand the regulation of lactation and to be able to assess which factors could interfere with this process.  相似文献   
63.
BACKGROUND: The axillobilateral breast approach (ABBA) is a procedure allowing thyroid resection without scarring at the neck. We operated on a series of 26 patients with this technique. METHOD: Via incisions at the edge of the mamilla and axilla, trocars are placed subcutaneously under the platyma. Dissection is performed bluntly and with an ultrasonographic scalpel under videoscopic control. The procedure itself corresponds to conventional surgery. The specimen is removed through the axillary trocar. RESULTS: Twenty-six female patients underwent thyroid resection using the ABBA technique. Subtotal resection was performed in 24. Mean operation times were 111 min (unilateral) and 187 min (bilateral). In none of these cases was conversion necessary. One transient recurrent laryngeal nerve palsy and one paresis of the arm plexus were found postoperatively. CONCLUSION: In selected patients the ABBA technique is feasible and safe with the mandatory radicalness. The primary aim of this method is the cosmetic result.  相似文献   
64.
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   
65.
The life time of hip endoprostheses is in part limited by aseptic loosening. The aim of this study was to produce a digital system for recording shaft loosening in such endoprostheses using acceleration sensors. Four identical prosthetic shafts were each set with 3.2-axial acceleration sensors and placed in artificial femurs. In order to simulate a firm fit, one prosthesis was fixed with bone cement; a loose fit was fixed with a surrounding silicon shell 0.5 mm thick. Simulation of the transition from firm to loose in the other two prostheses was attained by the distal 2/3 or 1/3 being cemented, with the rest surrounded by a silicone shell. A weak oscillation was initiated via a damped falling weight. Using a fast Fourier transformation it was possible to make a global evaluation of the measurement curves. A wavelet transformation could be used to differentiate firm or loose prostheses. A third order Daubechies filter recognized the deviation in the main oscillation, made visible by an increase in amplitude. The results encourage the development of an implantable, telemetrically functioning total system which would allow digital quality assurance when integrated into the endoprosthesis.  相似文献   
66.
The 2006, annual meeting of the senior physicians and emergency medical technicians of the German Air Rescue Service (Deutschen Rettungsflugwacht, DRF) was titled “From Concept to Practice”. The themes of security in the air rescue services and the current practice of cardiopulmonary respiration were discussed. In addition, different concepts and networks for treating patients with acute coronary syndrome or severe trauma were presented. The training of emergency technicians and quality assessment using the database of the whole TeamDRF was explained. New helicopter stations as well as long-range transport using normal aviation by the TeamDRF were presented.  相似文献   
67.
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   
68.
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   
69.
70.
The guidelines regarding medical rehabilitation have changed. When applying for medical rehabilitation, the International Classification of Functioning (ICF) must be used for young adults with somatic and/or psychiatric diseases. The ICF is an appropriate tool to assess the outcome of rehabilitation in children and adolescents. Nowadays the ICF is used in rehabilitation hospitals; in former times the Functional Independence Measure (FIM) was used. The different criteria of the ICF such as personal factors, environmental factors, body function and structure (impairment), activities (limitation) and participation (restriction) are explained. A case report is presented which shows the outcome of rehabilitation according to FIM and ICF in graphic form.  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