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   349篇
  免费   20篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   2篇
妇产科学   6篇
基础医学   48篇
口腔科学   30篇
临床医学   29篇
内科学   49篇
皮肤病学   2篇
神经病学   12篇
特种医学   9篇
外科学   32篇
综合类   30篇
预防医学   58篇
眼科学   9篇
药学   30篇
中国医学   4篇
肿瘤学   13篇
  2024年   1篇
  2023年   5篇
  2022年   9篇
  2021年   27篇
  2020年   15篇
  2019年   18篇
  2018年   15篇
  2017年   7篇
  2016年   13篇
  2015年   15篇
  2014年   18篇
  2013年   27篇
  2012年   28篇
  2011年   22篇
  2010年   15篇
  2009年   11篇
  2008年   13篇
  2007年   10篇
  2006年   11篇
  2005年   9篇
  2004年   9篇
  2003年   5篇
  2002年   5篇
  2001年   4篇
  2000年   3篇
  1999年   8篇
  1998年   3篇
  1993年   1篇
  1992年   3篇
  1991年   3篇
  1990年   6篇
  1989年   3篇
  1988年   4篇
  1987年   6篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1980年   2篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1973年   3篇
  1972年   1篇
排序方式: 共有370条查询结果,搜索用时 15 毫秒
101.
In the search for agents effective against immune-mediated disorders and inflammation, we have screened Malaysian medicinal plants for the ability to inhibit the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the surface of murine endothelial cells (F-2), and mouse myeloid leukaemia cells (M1), respectively. Of 41 kinds (29 species, 24 genera, 16 families) of Malaysian plants tested, 10 and 19 plant samples significantly downregulated the expression of ICAM-1 and VCAM-1, respectively. Bioassay-directed fractionation of an extract prepared from the bark of Goniothalamus andersonii showed that its ingredients, goniothalamin (1) and goniodiol (2) inhibited the cell surface expression of both ICAM-1 and VCAM-1. The present results suggest that Malaysian medicinal plants may be abundant natural resources for immunosuppressive and antiinflammatory substances.  相似文献   
102.
Despite the major anatomical importance of the human ilium in medicine and forensic investigations, little is understood about its pattern of growth. This study was conducted to investigate the changes in the surface area of the human ilium from birth through to adolescence in 80 human ilia. A photographic image of the pelvic surface of each bone was taken and examined using an image quantification package. The surface areas of four regions of interest were quantified: the auricular, post‐auricular (PA), iliac fossa, and whole pelvic surface of the ilium. The results highlight a rapid increase in surface area for all regions in the first few years after birth which continues, albeit at a slower rate, until ~4 years of age when the rate of growth is further reduced. Although the ilium and its various components continue to grow between 5 years and puberty, the rate of growth is markedly reduced until puberty when growth of the pelvis again increases. Interestingly, analysis of the differential growth of the auricular region compared with the PA region throughout development suggests that the PA region exhibits more advanced growth. This may indicate that its role in structural development for the purposes of preparation and maintenance of bipedal stance and locomotion may have been previously poorly understood. Anat Rec, 296:1688–1694, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
103.
Platelet rich plasma clot- releasate (PRCR) shows significant influence on tissue regeneration in clinical trials. Although, the mechanism of PRCR effect on fibroblast differentiation has been studied on 2D culture system, a detailed investigation is needed to establish the role of PRCR in cell seeded in 3D scaffolds. Therefore, a study was conducted to evaluate the influence of PRCR in fibroblasts (DFB) differentiation and extracellular matrix formation on both 3D and 2D culture systems. Cell viability was measured using MTT assay and DFB differentiation was evaluated by determining the expression levels of nucleostamin and alpha smooth muscle actin (α-SMA), using indirect immunostaining and Western blotting. The expression levels of extracellular matrix genes (collagen-I, collagen-III, fibronectin and laminin) and focal adhesion formation gene (integrin beta-1) were measured using Real-time PCR. The PRCR at 10% showed significant effect on cells viability compared with 5% and 20% in both culture environments. The decrease in the expression levels of nucleostamin and the increase in α-SMA signify the DFB differentiation to myofibroblast-like cells that was prominently greater in 3D compared to 2D culture. In 3D culture systems, the total collage production, expression levels of the extracellular matrix gene and the focal adhesion gene were increased significantly compared to 2D culture. In conclusion, 3D culture environments enhances the proliferative and differentiation effects of PRCR on DFB, thereby potentially increases the efficacy of DFB for future tissue engineering clinical application.  相似文献   
104.
We report a 47-year-old Malay lady, para 4 + 1, with known medical history of hypertension whom presented at Emergency Department with severe anaemia, most likely secondary to menorrhagia caused by uterine fibroids. Her haemoglobin was 5.5 g/dl and she was transfused with three units of packed cell without any adverse reaction, her haemoglobin level increased to 9.8 g/dl. She was then planned for total abdominal hysterectomy and bilateral salpingo-oophorectomy later. Four months later when she came for the elective surgery, her pre transfusion investigations showed blood group as B Rh D positive, with a probable R1R1 phenotype. Her antibody screening was positive in all the three panel cells. Further testings showed a negative Direct Coomb’s test and negative autocontrol, antibody identification showed pan-agglutination reaction on all 11 panel cells with enzyme enhancement. Patient’s red cell phenotype was Jk(a−b−). Anti-Jk3 was suspected and further confirmed in the reference laboratory by phenotyping as well as negative urea lysis test. This case report highlights an extremely rare but clinically significant anti-JK3 antibody detected during pretransfusion testing. This phenotype is rare in the white population, more commonly seen in various polynesians. Increased awareness among the blood bank personnel regarding the variability of the blood group phenotype and the capricious nature of the Kidd antibodies may contribute to the better management of these patients.  相似文献   
105.
Vertical transmission may contribute to the maintenance of arthropod-borne viruses, but its existence in chikungunya virus (CHIKV) is unclear. Experimental vertical transmission of infectious clones of CHIKV in Aedes aegypti mosquitoes from Malaysia was investigated. Eggs and adult progeny from the second gonotrophic cycles of infected parental mosquitoes were tested. Using polymerase chain reaction (PCR), 56.3% of pooled eggs and 10% of adult progeny had detectable CHIKV RNA, but no samples had detectable infectious virus by plaque assay. Transfected CHIKV RNA from PCR-positive eggs did not yield infectious virus in BHK-21 cells. Thus, vertical transmission of viable CHIKV was not demonstrated. Noninfectious CHIKV RNA persists in eggs and progeny of infected Ae. aegypti, but the mechanism and significance are unknown. There is insufficient evidence to conclude that vertical transmission exists in CHIKV, as positive results reported in previous studies were almost exclusively based only on viral RNA detection.  相似文献   
106.
The applicability of the Willems et al. model was verified on a collected sample of Malay (Malaysian nationality) children. This sample was split in a reference sample to develop a Malay-specific prediction model based on the Willems et al. method and in a test sample to validate this new developed model. Next, the incorporation of third molars into this model was analyzed. Panoramic radiographs (n?=?1,403) of Malay children aged between 4 and 14.99 years (n?=?702) and subadults aged between 15 and 23.99 years (n?=?701) were collected. The left mandibular seven permanent teeth of the children were scored based on the staging technique described by Demirjian and converted to age using the Willems et al. method. Third molar development of all individuals was staged based on the technique described by Gleiser and Hunt modified by Kohler. Differences between dental age and chronological age were calculated and expressed in mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The Willems et al. model verified on the collected Malay children overestimated chronological age with a ME around 0.45 year. Small differences in ME, MAE, and RMSE between the verified Malay-specific prediction model and the Willems et al. model were observed. An overall neglected decrease in RMSE was detected adding third molar stages to the developed permanent teeth model.  相似文献   
107.
108.
109.
110.
In this work, batch adsorption experiments were carried out to investigate the suitability of prepared acid activated carbons in removing heavy metal ions such as nickel(II), lead(II) and chromium(VI). Acid activated carbons were obtained from oil palm and coconut shells using phosphoric acid under similar activation process while the differences lie either in impregnation condition or in both pretreatment and impregnation conditions. Prepared activated carbons were modified by dispersing hydrated iron oxide. The adsorption equilibrium data for nickel(II) and lead(II) were obtained from adsorption by the prepared and commercial activated carbons. Langmuir and Freundlich models fit the data well. Prepared activated carbons showed higher adsorption capacity for nickel(II) and lead(II). The removal of chromium(VI) was studied by the prepared acid activated, modified and commercial activated carbons at different pH. The isotherms studies reveal that the prepared activated carbon performs better in low concentration region while the commercial ones in the high concentration region. Thus, a complete adsorption is expected in low concentration by the prepared activated carbon. The kinetics data for Ni(II), Pb(II) and Cr(VI) by the best selected activated carbon fitted very well to the pseudo-second-order kinetic model.  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