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   4845篇
  免费   260篇
  国内免费   31篇
耳鼻咽喉   51篇
儿科学   144篇
妇产科学   77篇
基础医学   576篇
口腔科学   442篇
临床医学   377篇
内科学   1059篇
皮肤病学   76篇
神经病学   324篇
特种医学   234篇
外科学   535篇
综合类   48篇
预防医学   540篇
眼科学   93篇
药学   345篇
中国医学   26篇
肿瘤学   189篇
  2023年   42篇
  2022年   133篇
  2021年   176篇
  2020年   134篇
  2019年   150篇
  2018年   186篇
  2017年   129篇
  2016年   118篇
  2015年   185篇
  2014年   237篇
  2013年   239篇
  2012年   348篇
  2011年   422篇
  2010年   242篇
  2009年   162篇
  2008年   267篇
  2007年   285篇
  2006年   216篇
  2005年   224篇
  2004年   155篇
  2003年   125篇
  2002年   120篇
  2001年   91篇
  2000年   87篇
  1999年   73篇
  1998年   40篇
  1997年   50篇
  1996年   52篇
  1995年   31篇
  1994年   32篇
  1993年   25篇
  1992年   40篇
  1991年   42篇
  1990年   23篇
  1989年   37篇
  1988年   28篇
  1987年   23篇
  1986年   20篇
  1985年   28篇
  1984年   14篇
  1983年   21篇
  1982年   13篇
  1981年   12篇
  1980年   6篇
  1979年   7篇
  1978年   5篇
  1977年   5篇
  1976年   7篇
  1971年   5篇
  1967年   4篇
排序方式: 共有5136条查询结果,搜索用时 15 毫秒
91.
92.
Abstract. Thomas J‐A II, Gerber L, Moreira DM, Hamilton RJ, Bañez LL, Castro‐Santamaria R, Andriole GL, Isaacs WB, Xu J, Freedland SJ (Durham VA Medical Center, Durham, NC, USA; Duke University School of Medicine, Durham, NC, USA; The Author Smith Institute for Urology, New Hyde Park, NY, USA; Memorial Sloan‐Kettering Cancer Center, New York, NY, USA; GlaxoSmithKline, Research Triangle Park, NC, USA; Washington University School of Medicine, St. Louis, MO, USA; Johns Hopkins Hospital, Baltimore, MD, USA; Wake Forest University, Winston‐Salem, NC, USA; and Duke University School of Medicine, Durham, NC, USA). Prostate cancer risk in men with prostate and breast cancer family history: results from the REDUCE study (R1). J Intern Med 2012; 272 : 85–92. Background. To what degree the associations between PCa risk and family history of prostate cancer (PCa) and/or breast cancer (BCa) are attributable to screening biases is unclear. We examined these questions within the REDUCE study, where biopsies were largely independent of prostate specific antigen (PSA) minimizing screening biases. Methods. Data were from REDUCE, which tested dutasteride 0.5 mg daily for PCa risk reduction in men with PSA 2.5–10.0 ng mL?1 and a negative prestudy biopsy. Among men undergoing at least one on‐study biopsy with complete data (n = 6415; 78.1%), the association between family history and PCa risk was tested using multivariate logistic regression adjusting for clinicodemographic characteristics. Results. A family history of PCa alone was associated with increased PCa diagnosis (OR: 1.47, 95%CI: 1.22–1.77). In North America, PCa family history was not related to PCa diagnosis (OR: 1.02, 95%CI: 0.73–1.44), whereas outside North America, PCa family history was significantly related to diagnosis (OR: 1.72, 95%CI: 1.38–2.15) (P‐interaction = 0.01). A family history of both PCa and BCa (OR: 2.54, 95%CI: 1.72–3.75) but not BCa alone (OR: 1.04, 95%CI: 0.84–1.29) was associated with increased PCa risk versus no family history and irrespective of geographical region. Conclusions. In REDUCE, PCa family history was significantly related to PCa diagnosis, although only for men outside North America. The presence of both PCa and BCa family history significantly increased risk versus PCa family history alone, irrespective of geographical region. Ultimately, our observations may support the need for changes in how we address family history in terms of both risk of PCa diagnosis and general risk stratification.  相似文献   
93.
94.
95.
ObjectiveThe aim of the study was to evaluate the effect of topical fluoride gel NaF 2% application on antioxidant parameters of whole saliva from children.DesignThe saliva mechanically stimulated with parafilm was collected from 25 children (6–12 years) attending the Clinic of Paediatric Dentistry of Universidade Cruzeiro do Sul, São Paulo, Brazil, before (control group) and immediately after application of neutral fluoride gel NaF 2% (fluoride-gel group), according to the Standards for Research Using Human Subjects, Resolution 196/96 of the USA National Health Council of 10/10/1996. Afterwards, pre-post ferric-reducing antioxidant power (FRAP), trolox-equivalent antioxidant capacity (TEAC), uric acid, reduced/oxidised glutathione content (GSH/GSSG) and total peroxidase activity (TPO) were evaluated in whole saliva of both groups.ResultsAll non-enzymatic antioxidant parameters were augmented by fluoride-gel NaF 2% application, whereas a notable reduction (31%) of peroxidase activity was concomitantly observed in the children's saliva (p  0.05). Nevertheless, the reducing power of saliva was kept unaltered under these circumstances (p  0.05).ConclusionsDespite the reduced activity of peroxidase (an important antimicrobial and antioxidant enzyme), the topical fluoride gel NaF 2% favourably stimulated the release of non-enzymatic antioxidant components of saliva, sustaining the reducing power of saliva and the natural defences of the oral cavity.  相似文献   
96.
Our aim was to evaluate cephalometrically the preoperative inclination of the incisors in a group of 50 patients with Class III dentofacial deformities whose immediate preoperative lateral cephalometric radiographs were analysed after they had been treated by maxillary advancement. The radiographs were hand-traced by the same operator who made the cephalometric analysis. Mean values for each measurement were compared with the normal values using Student's t-test (p<0.05). Results showed significantly increased inclination of the upper incisors, with a mean U1-NA angle of 27.58° and a mean U1-PP angle of 116°. The lower incisors were also inclined lingually, with a mean L1-NB angle of 22.53° and a mean IMPA of 83.13°. Thirty-five of the patients had labial inclination of the upper, and 28 lingual inclination of the lower, incisors. Mean inclinations of upper and lower incisors differed from the normal values, and the inclination of the lower incisors was more likely to be decompensated than that of the upper incisors.  相似文献   
97.

Background

No study has investigated the alterations in the flexibility of beginners using an experimental protocol with basic techniques of Capoeira.

Purpose

To analyze the effects of 8 weeks of Capoeira progressive training program on the flexibility of beginners.

Methods

Twenty-one individuals divided in two groups (Capoeira: n = 13; 26.1 ± 7.2 years; 22.7 ± 2.7 kg m2(?1) and control: n = 08; 27.1 ± 0.5 years; 24.3 ± 3.3 kg m2(?1)) participated in the study. The Capoeira group performed 8 weeks of Capoeira progressive training program (two sessions per week lasting 60 min each). The experimental protocol used was exclusively based on the basic techniques of a programmed Capoeira training system. Before and after the intervention, measurements were performed aiming to analyze (1) trunk flexion flexibility through a sit-and-reach test using a Wells’ Bench (WBtf), (2) passive tension (PThf), and (3) maximum amplitude of hip flexion (MAhf) through goniometry.

Results

A two-way ANOVA revealed a main effect of group by time interaction to PThf (F = 11.797; P = 0.003; η p 2  = 0.383) and MAhf (F = 9.650; P = 0.006; η p 2  = 0.337). No significant main effect of group by time interaction occurred to WBtf (F = 3.320; P = 0.084; η p 2  = 0.149). The relative changes (? %) before and after the intervention in both groups showed that the Capoeira group significantly differed to the control group in the PThf (Capoeira: 46.2 ± 29.9 % vs. control: 5.7 ± 27.6 %; P = 0.003) and MAhf (Capoeira: 22.4 ± 24.5 % vs. control: ?6.1 ± 13.1 %; P = 0.006).

Conclusion

Eight weeks of Capoeira progressive training program resulted in a significant improvement in angular flexibility for beginners.
  相似文献   
98.
The notable evolution of heart transplant (HTX) has paralleled the capacity of diagnosing rejection and, consequently, initiating timely treatment. Acute cellular rejection, diagnosed by endomyocardial biopsy, is the most frequent in the first 6 months after HTX. HLA matching is not routinely performed in HTX due to the absence of consensus regarding its usefulness. However, the use of HLA typing might be underscored if it could predict an increased risk of rejection. Therefore, the aim of this study was to evaluate, at a public cardiology center in Brazil, the association between HLA mismatches and the incidence of acute cellular rejection in the first 6 months after HTX. Data were obtained from hospital records and from the National Transplant System. Overall, there was no association between the number of HLA mismatches and the frequency of acute cellular rejection, but there was a tendency toward a higher incidence of rejection with HLA‐DR incompatibility.  相似文献   
99.
100.
Introduction: Diabetes Mellitus has been considered an epidemic by the World Health Organization, with a high risk of morbidity and mortality. The treatment of this pathology consists in glycemic control, which can be done by oral hypoglycemic agents, insulin therapy, dietary guidance, regular physical activity, and psychosocial support. In addition, other adjuvant treatments are employed, such as phytotherapic, and one of the most used plants is Bauhinia forficata.

Areas covered: In the current review, patents using Bauhinia forficata for the Diabetes Mellitus treatment have been analyzed. There were 03 patents in WIPO, 01 in Espacenet, 01 in USPTO, and 02 in INPI.

Expert opinion: Patents on the adjuvant treatment of Diabetes Mellitus by Bauhinia forficata are discussed. Although there are some phytotherapy products containing this medicinal plant which has hypoglycemic effect here is still a need for the development of more products based on natural resources, for the treatment of this pathology, without side effects and with other benefits, to assist in the glycemia control in diabetic patients, and to improve their quality of life.  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