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   250篇
  免费   13篇
  国内免费   2篇
儿科学   1篇
妇产科学   3篇
基础医学   34篇
口腔科学   3篇
临床医学   14篇
内科学   89篇
神经病学   16篇
特种医学   8篇
外科学   24篇
综合类   4篇
预防医学   18篇
眼科学   13篇
药学   25篇
中国医学   1篇
肿瘤学   12篇
  2024年   1篇
  2023年   3篇
  2022年   5篇
  2021年   16篇
  2020年   10篇
  2019年   14篇
  2018年   9篇
  2017年   6篇
  2016年   9篇
  2015年   11篇
  2014年   11篇
  2013年   13篇
  2012年   25篇
  2011年   21篇
  2010年   12篇
  2009年   8篇
  2008年   23篇
  2007年   17篇
  2006年   7篇
  2005年   11篇
  2004年   6篇
  2003年   6篇
  2002年   6篇
  2001年   2篇
  2000年   3篇
  1999年   2篇
  1996年   1篇
  1993年   1篇
  1989年   1篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
  1980年   1篇
排序方式: 共有265条查询结果,搜索用时 46 毫秒
21.
The aim of this study was to determine the risks of human anaplasmosis in an area of central Slovakia endemic for Lyme borreliosis. The circulation of Anaplasma phagocytophilum in ticks and wild animals has been observed in natural foci in this area for several years. Samples of human sera from patients with Lyme borreliosis and persons with a history of recent tick bite and clinical symptoms indicating Lyme borreliosis were collected in central Slovakia. A total of 76 human sera were analyzed using an indirect HGE IgG immunofluorescent assay kit. IgG antibodies against A. phagocytophilum were found in 19 (25%) sera (15 female, 4 male patients). A. phagocytophilum infection was serologically confirmed in one (3.8%) child, 12 (38.7%) persons aged 22-56 and six (31.6%) persons older than 56. A statistically significant difference in seroprevalence (P < 0.01) was observed between children (3.8%, 1/26) and adults (36%, 18/50). Antibodies against A. phagocytophilum were detected in seven patients with clinically diagnosed Lyme borreliosis and in another seven individuals with assessed antiborrelia antibodies. IgG antibodies against A. phagocytophilum were detected in five persons seronegative for borrelia. The most frequent clinical symptoms in patients with positive A. phagocytophilum serology were cephalalgia, arthralgia, myalgia, fever, exanthema, neurological symptoms and lymphadenopathy. Positive sera were obtained from patients living in villages and towns in the orographic entities Vtácnik (5/19), Stiavnické vrchy (1/19), Kremnické vrchy (10/19) and Ziarska kotlina (3/19). Our results demonstrate the risk of acquiring A. phagocytophilum infection in natural foci in central Slovakia. Human anaplasmosis should be considered in the differential diagnosis, especially in cases of acute febrile illness with tick-bite history.  相似文献   
22.
This study examined the various ways adults engage and support youth in connected learning settings, which are focused on supporting youth in their interests or passions. Youth from 5 Chicago community‐based, out‐of‐school time (OST) programs participated in focus groups on the topic of adult–youth relationships. Participants reported characteristics and behaviors of supportive adults as well as the outcomes associated with those behaviors. Analyses revealed that the following characteristics of adults enabled engagement and relationship development: (a) mutual respect, (b) genuine interest, (c) ongoing communication and friendship, and (d) going above and beyond. Youth also identified the specific ways that adults supported them: (a) guidance and motivation, (b) skill‐based support, (c) role modeling, (d) connecting, (e) emotional support, and (f) cultivating youth voice. Finally, participants reported the following outcomes related to such support: (a) social capital, (b) a sense of empowerment and control of their futures, and (c) a sense of acceptance and validation. This study is a contribution to the literature on adult–youth relationships in connected learning sites and draws attention to the potential socioemotional and instructional benefits of such programs. Our study also highlights the various ways that adults in OST programs can successfully engage youth and form relationships.  相似文献   
23.
24.
25.
The differentiation of colorectal cancer cells is associated with the arrest of tumor growth and tumor regression. However, the mechanism of such tumor cell differentiation has not yet been elucidated. Several adenocarcinoma cell lines, including HT29 which differentiates only upon stimulation with a differentiation agent, have been used for the study of colorectal cells. Since we had previously obtained variable results during analyses of these cells, we selected several clones of this cell line. In this study, four clones of the parental HT29 cells, H8, G9, G10 and A3, were characterized. All of them differentiated upon treatment with sodium butyrate as the differentiation agent but they appeared different in their response regarding some of the markers of differentiation. As revealed by ultrastructural analysis, H8 and G10 clones formed numerous intercellular cysts with microvilli whereas these structures were found only occasionally in G9 and A3 clones. An elevated level of the indicator of cell differentiation, CEACAM 1, was found in H8 and G10 clones and the activity of alkaline phosphatase, another important marker of colorectal cell differentiation, was up-regulated and highly increased upon butyrate treatment in the H8 clone. Phosphorylation of p38 MAPK was increased in H8 and A3 butyrate-treated clones. According to the levels of cleaved PARP and activated caspase-3, the apoptotic response to butyrate appeared similar in all four clones, while electronoptic analysis revealed that clones G9 and A3 were more perceptive to butyrate-induced apoptosis. In conclusion, our data showed considerable heterogeneity in morphology and some enzymatic activity of the cloned cells. This fact may contribute to the evidence that many HT29 cells possess multipotent information similar to that of stem cells of the normal intestinal crypt.  相似文献   
26.
Purpose: Stereotactic radiofrequency amygdalohippocampectomy (SAHE) has been modified recently in our center for the therapy of mesial temporal epilepsy (MTLE). It has promising clinical results comparable with microsurgical amygdalohippocampectomy despite smaller volume reduction of the hippocampus. We hypothesized that the extent of perirhinal and entorhinal cortex (PRC, EC) reduction could explain the clinical outcome. Therefore, we performed, retrospectively, volumetric analysis of PRC and EC and compared it with the seizure control. Methods: Twenty‐six consecutive patients with MTLE treated by SAHE were included. PRC and EC volumes were measured from magnetic resonance imaging (MRI) records obtained before and 1 year after SAHE. The clinical outcome was assessed each year after SAHE using Engel’s classification. Key Findings: Twenty‐six patients were analyzed. The volume of PRC decreased by 46 ± 17% (p < 10−12); EC volume decreased by 56 ± 20% (p < 10−10). Two years after the procedure, 73% of patients were classified as Engel’s I, 19% as Engel’s II; in 2 (8%) the treatment failed (were reoperated). Eighteen patients finished 3 years follow‐up; 72% of them were classified as Engel’s I, 17% as Engel’s II, and in 2 (11%) above‐mentioned patients the treatment failed. Thirteen patients finished 4 years of follow‐up, 11 of them as Engel’s I. There was no significant correlation of the clinical outcome to PRC and EC volume reductions. Significance: The clinical effect of SAHE is not clearly explained by the volume reductions of PRC and EC (nor of the hippocampus and the amygdala). It promotes opinion that the extent of resection/destruction is not important for seizure outcomes.  相似文献   
27.
Foreword In 2005, for the first time, an expert panel named “The Bariatric Scientific Collaborative Group” (BSCG), was appointed through a joint effort of the major European Scientific Societies which are active in the field of obesity management. Societies that constituted this panel were: International Federation for the Surgery of Obesity – European Chapter (IFSO-EC), European Association for the Study of Obesity (EASO), European Childhood Obesity Group (ECOG) and the International Obesity Task Force (IOTF) which was represented during the completion process by its representatives. The BSCG was composed of officers representing the respective Scientific Societies (including four acting Presidents, two past Presidents, one Honorary President, and three Executive Directors). The panel was also balanced by the presence of many other opinion leaders in the field of obesity. The BSCG composition allowed coverage of the key disciplines in comprehensive obesity management, as well as being reflective of European geographic and ethnic diversity. This joint BSCG Expert Panel has convened several meetings which were entirely focused on guideline creation during the past 2 years. There was a specific effort to develop and concur on clinical guidelines which reflect current knowledge, expertise and evidence- based data on treatment of morbid obesity.  相似文献   
28.
Macaques were immunized with SF162 Env-based gp140 immunogens and challenged simultaneously with the CCR5-tropic homologous SHIV(SF162P4) and the CXCR4-tropic heterologous SHIV(SF33A) viruses. Both mock-immunized and immunized animals became dually infected. Prior immunization preferentially reduced the viral replication of the homologous virus during primary infection but the relative replication of the two coinfecting viruses during chronic infection was unaffected by prior immunization, despite the fact that five of six immunized animals maintained a significantly lower overall viral replication that the control animals. Neutralizing antibodies participated in controlling the replication of SHIV(SF162P4), but not that of SHIV(SF33A). Dual infection resulted in the emergence and predominance within the circulating CCR5 virus pool, of a variant with a distinct neutralization phenotype. The signature of this variant was the presence of three amino acid changes in gp120, two of which were located in the receptor and coreceptor binding sites. Also, a significant fraction of the viruses circulating in the blood, as early as two weeks post-infection, was recombinants and prior immunization did not prevent their emergence. These findings provide new insights into the dynamic interaction of CCR5- and CXCR4-tropic HIV isolates that are potentially relevant in better understanding HIV-mediated pathogenesis.  相似文献   
29.
30.
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