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   1925篇
  免费   88篇
  国内免费   13篇
耳鼻咽喉   10篇
儿科学   27篇
妇产科学   5篇
基础医学   188篇
口腔科学   59篇
临床医学   127篇
内科学   484篇
皮肤病学   21篇
神经病学   148篇
特种医学   100篇
外科学   305篇
综合类   6篇
预防医学   36篇
眼科学   99篇
药学   216篇
中国医学   4篇
肿瘤学   191篇
  2023年   32篇
  2022年   25篇
  2021年   61篇
  2020年   44篇
  2019年   50篇
  2018年   40篇
  2017年   45篇
  2016年   45篇
  2015年   55篇
  2014年   66篇
  2013年   95篇
  2012年   158篇
  2011年   146篇
  2010年   72篇
  2009年   73篇
  2008年   103篇
  2007年   105篇
  2006年   140篇
  2005年   121篇
  2004年   107篇
  2003年   115篇
  2002年   105篇
  2001年   27篇
  2000年   8篇
  1999年   25篇
  1998年   18篇
  1997年   13篇
  1996年   8篇
  1995年   7篇
  1994年   12篇
  1993年   6篇
  1992年   13篇
  1991年   7篇
  1990年   4篇
  1989年   4篇
  1988年   6篇
  1987年   5篇
  1986年   5篇
  1985年   11篇
  1984年   4篇
  1983年   5篇
  1982年   5篇
  1979年   3篇
  1977年   7篇
  1976年   3篇
  1974年   2篇
  1970年   2篇
  1969年   3篇
  1968年   3篇
  1910年   1篇
排序方式: 共有2026条查询结果,搜索用时 15 毫秒
31.
Abstract: The barrier of ABO-incompatible kidney transplantation is the presence of anti-A and anti-B antibodies in the recipient's circulating blood. Double filtration plasmapheresis (DFPP) is usually used to eliminate those antibodies. We tried cryofiltration apheresis (CRYO) in 2 recipients. Patient 1 was a 45-year-old male with B, Rh(±). The titers of IgM anti-A antibody were only reduced from ×64 to ×32 by the end of 3 sessions of standard CRYO. Renal allografting was not performed. Case 2 was a 29-year-old male with B, Rh(+). CRYO was introduced for 3 sessions. The initial IgM and IgG titers were ×128 and negative, respectively. The standard CRYO system was modified by temperature, treated volume, and filter pore size. The IgM anti-A antibody titer was markedly reduced to ×2 after the final session of CRYO. The donor was a 56-year-old father with A, Rh(+). Tacrolimus, azathio-prine, methylprednisolone, and antilymphocyte globulin were used as the introductory immunosuppression therapy.  相似文献   
32.
33.
34.
Cognitive behavioral therapy (CBT), an effective treatment for depression, targets self-referential processing of emotional stimuli. We examined the effects of CBT on brain functioning during self-referential processing in depressive patients using functional magnetic resonance imaging (fMRI). Depressive patients (n = 23) and healthy participants (n = 15) underwent fMRI scans during a self-referential task using emotional trait words. The depressive patients had fMRI scans before and after completing a total of 12 weekly sessions of group CBT for depression, whereas the healthy participants underwent fMRI scans 12 weeks apart with no intervention. Before undergoing CBT, the depressive patients showed hyperactivity in the medial prefrontal cortex (MPFC) during self-referential processing of negative words. Following CBT, MPFC and ventral anterior cingulate cortex (vACC) activity during self-referential processing among depressive patients was increased for positive stimuli, whereas it was decreased for negative stimuli. Improvements in depressive symptoms were negatively correlated with vACC activity during self-referential processing of negative stimuli. These results suggest that CBT-related improvements in depressive symptoms are associated with changes in MPFC and vACC activation during self-referential processing of emotional stimuli.  相似文献   
35.
36.
37.
MRP has been identified as another multidrug-resistance (MDR) gene and may be involved in an alternative MDR mechanism in some solid tumors. We investigated the expression of MRP mRNA in multidrug-resistant KB sublines (KB-8-5, KB-C2, C-A40 and C-A120), human non-small-cell lung carcinomas (NSCLC), gastric and colorectal carcinomas, and compared it with that in drug-sensitive human KB cells, MRP gene expression was elevated in 8 of 9 (89%) squamous-cell carcinomas of the lung. Furthermore, MRP expression in 4 squamous-cell carcinomas (L13, 18, 19 and 20) was more than 3.6 times higher than in KB-3-I cells, and the average MRP mRNA expression level of all squamous-cell carcinomas was significantly higher than that of adenocarcinoma of the lung and of colorectal and gastric carcinomas. These results suggested that the MRP is responsible, at least in part, for drug resistance in some squamous-cell carcinomas of the lung. © 1996 Wiley-Liss, Inc.  相似文献   
38.
Background: Metabolic syndrome (MS) is a condition that consists of several disorders, and the individual impact of these disorders on metabolic dysfunction-associated fatty liver disease (MAFLD) is still not clear in a combined diagnosis of MS. In this study, we aimed to investigate the effect of MS on advanced fibrosis in patients with MAFLD.Methods: We recruited the patients from our gastroenterology out-patient clinic who were being followed up for MAFLD. MAFLD was diagnosed with liver biopsy in all patients. The frequency of MS and other metabolic parameters were also compared between groups with advanced fibrosis and groups in which fibrosis was not as advanced.Results: In total, we enrolled 424 biopsy-proven MAFLD patients to the study. In univariate analysis, individuals with greater age, body mass index (BMI), higher aspartate transaminase (AST), MS, impaired fasting glucose, hypertension, enlarged waist circumference (WC), diabetes mellitus (DM), and women had significantly increased risk for fibrosis. In multivariate analysis, it was found that DM, greater age, higher BMI, and increased AST were seen more commonly in MAFLD patients with advanced fibrosisConclusion: Greater age, a higher BMI, higher AST and a diagnosis of diabetes were more commonly associated with advanced fibrosis. However, DM was found to be the strongest predictive factor of advanced fibrosis in our cohort (OR: 2.495). Multivariate analyses did not indicate a significantly common occurrence of MS in the advanced fibrosis group, despite its important role in MAFLD pathophysiology.  相似文献   
39.
Behaviors comparable to human child maltreatment are observed widely among mammals, in which parental care is mandatory for offspring survival. This article first reviews the recent findings on the neurobiological mechanisms for nurturing (infant caregiving) behaviors in mammals. Then the major causes of attack/desertion toward infants (conspecific young) in nonhuman mammals are classified into five categories. Three of the categories are ‘adaptive’ in terms of reproductive fitness: (i) attack/desertion toward non‐offspring; (ii) attack/desertion toward biological offspring with low reproductive value; and (iii) attack/desertion toward biological offspring under unfavorable environments. The other two are nonadaptive failures of nurturing motivation, induced by: (iv) caregivers’ inexperience; or (v) dysfunction in caregivers’ brain mechanisms required for nurturing behavior. The proposed framework covering both adaptive and nonadaptive factors comprehensively classifies the varieties of mammalian infant maltreatment cases and will support the future development of tailored preventive measures for each human case. Also included are remarks that are relevant to interpretation of available animal data to humans: (1) any kind of child abuse/neglect is not justified in modern human societies, even if it is widely observed and regarded as adaptive in nonhuman animals from the viewpoint of evolutionary biology; (2) group‐level characteristics cannot be generalized to individuals; and (3) risk factors are neither deterministic nor irreversible.  相似文献   
40.
Follicular lymphoma (FL) is a germinal center-derived B-cell lymphoma that is known to proliferate in the intrafollicular region. However, lymphoma cells can be identified in the extrafollicular regions, which are related to disease dissemination. We purified the intrafollicular and extrafollicular regions of FL cells by laser microdissection and conducted microarray analysis in order to characterize the gene expression profiles of FL cells from both regions. BCL2 and genes of germinal B-cell markers clearly separated intrafollicular and extrafollicular regions of reactive follicular hyperplasia, suggesting the adequacy of the current analysis. In FL cases, cytokine-related genes were significantly enriched in extrafollicular regions compared with those in the intrafollicular regions. In intrafollicular regions of FL, cell-cycle–related genes were enriched. We found that the FL cells in the extrafollicular region more strongly expressed IL3RA and CXCL12 than those of intrafollicular regions. The cytokines might be also derived from stroma cells in the extrafollicular regions, which may initiate activation and migration of the tumor cells to this region. Our results suggest that FL cell interaction with surrounding stroma cells plays an important role in the pathophysiology of FL and that such interactions should be a good target for therapy.  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