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   665篇
  免费   40篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   18篇
妇产科学   29篇
基础医学   69篇
口腔科学   20篇
临床医学   52篇
内科学   114篇
皮肤病学   12篇
神经病学   61篇
特种医学   96篇
外科学   38篇
综合类   4篇
预防医学   34篇
眼科学   12篇
药学   77篇
中国医学   8篇
肿瘤学   61篇
  2023年   7篇
  2022年   5篇
  2021年   22篇
  2020年   15篇
  2019年   16篇
  2018年   21篇
  2017年   21篇
  2016年   24篇
  2015年   23篇
  2014年   26篇
  2013年   41篇
  2012年   72篇
  2011年   66篇
  2010年   37篇
  2009年   27篇
  2008年   43篇
  2007年   52篇
  2006年   47篇
  2005年   32篇
  2004年   28篇
  2003年   24篇
  2002年   20篇
  2001年   6篇
  2000年   4篇
  1999年   10篇
  1998年   5篇
  1996年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1978年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
  1965年   1篇
排序方式: 共有708条查询结果,搜索用时 31 毫秒
1.
2.
3.
Dietary polyphenols promote cardiometabolic health and are linked with long-chain polyunsaturated fatty acids in plasma phospholipids (LC-PUFA). The FADS2 polymorphisms are associated with LC-PUFA metabolism and overweight/obesity. This 4-week study examined the link between polyphenol intake, FADS2 variants (rs174593, rs174616, rs174576) and obesity in 62 overweight adults (BMI ≥ 25), allocated to consume 100 mL daily of either: Aronia juice, a rich source of polyphenols, with 1177.11 mg polyphenols (expressed as gallic acid equivalents)/100 mL (AJ, n = 22), Aronia juice with 294.28 mg polyphenols/100 mL (MJ, n = 20), or nutritionally matched polyphenol-lacking placebo as a control (PLB, n = 20). We analyzed LC-PUFA (% of total pool) by gas chromatography and FADS2 variants by real-time PCR. Four-week changes in LC-PUFA, BMI, and body weight were included in statistical models, controlling for gender and PUFA intake. Only upon AJ and MJ, the presence of FADS2 variant alleles affected changes in linoleic, arachidonic, and eicosapentaenoic acid (EPA). Upon MJ treatment, changes in EPA were inversely linked with changes in BMI (β= −0.73, p = 0.029) and weight gain (β= −2.17, p = 0.024). Only in subjects drinking AJ, the link between changes in EPA and anthropometric indices was modified by the rs174576 variant allele. Our results indicate the interaction between FADS2, fatty acid metabolism, and polyphenol intake in overweight subjects.  相似文献   
4.
Aging is associated with decreased sleep continuity, slow wave sleep (SWS), growth hormone (GH) release and an increased hypothalamo-pituitary-adrenocortical (HPA) system activity. Total sleep deprivation (TSD) is a strong stimulus for sleep. To determine if aging affects the response to TSD, for the first time the combined effects of TSD on conventional and spectral sleep electroencephalographic (EEG) parameters and GH, cortisol and prolactin secretion were compared in elderly (60–80 years; n = 7) vs. younger subjects (20–30 years; n = 7). MANOVA revealed a reduction of SWS in the elderly. TSD led to an increase in SWS, a decrease in sleep onset latency, rapid eye movement (REM) density and by trend REM-latency without a global group difference. GH was reduced, whereas prolactin was enhanced in the elderly. After TSD GH was unchanged and prolactin secretion was enhanced without group difference. Thus, the plasticity of the sleep-endocrine system in response to TSD is sustained during aging. The possible involvement of the GABAergic system, that seems not to be severely impaired with age, is proposed.  相似文献   
5.
6.
Considering the relatively high heritability of schizophrenia and the fact that it significantly reduces the reproductive fitness of affected individuals, it is not clear how the disorder is still maintained in human populations at a disproportionally high prevalence. Many theories propose that the disorder is a result of a trade‐off between costs and benefits of the evolution of exclusively human adaptations. There have also been suggestions that schizophrenia risk alleles are accompanied with increase in fitness of affected persons or their relatives in both past and current social contexts. The discoveries of novel schizophrenia‐related genes and the advancements in comparative genomics (especially comparisons of the human genome and the genomes of related species, such as chimpanzees and extinct hominids) have finally made certain evolutionary theories testable. In this paper, we review the current understanding of the genetics of schizophrenia, the basic principles of evolution that complement our understanding of the subject, and the latest genetic studies that examine long‐standing evolutionary theories of schizophrenia using novel methodologies and data. We find that the origin of schizophrenia is complex and likely governed by different evolutionary mechanisms that are not mutually exclusive. Furthermore, the most recent evidence implies that schizophrenia cannot be comprehended as a trait that has elevated fitness in human evolutionary lineage, but has been a mildly deleterious by‐product of specific patterns of the evolution of the human brain. In other words, novel findings do not support previous hypotheses stating that schizophrenia risk genes have an evolutionary advantage.  相似文献   
7.
Cardiac rhabdomyomas are common in tuberous sclerosis. We report a child who developed rhabdomyoma related arrhythmia refractory to antiarrhythmic drug therapy. Reversion of the atrial ectopic tachycardia was achieved with mammalian target of rapamycin pathway (mTOR) inhibitor sirolimus. As per our knowledge, this is the first time that sirolimus has been successfully used in this setting.  相似文献   
8.
The actual nature of spindle cell carcinoma has been debated extensively because of its rarity. It carries a poor prognosis, even when early-stage disease is diagnosed and resected. In view of the rarity and the significance of the histological diagnosis, we report a patient with rapidly progressing spindle cell lung carcinoma with soft tissue metastasis. Diagnosis was confirmed by immunohistochemistry finding. Analysis of the TP53 gene mutations by polymerase chain reaction and DNA sequencing revealed insertion of single thymine resulting in frameshift mutation in the exon 8. Prognosis of spindle cell lung carcinoma might be determined by the sarcoma component of the tumor and, based on that, we wonder if this type of lung carcinoma could be followed-up and treated by strategies for soft tissue sarcomas, because of its rapid, sarcomatous type of growth, beside the properly lung carcinoma oncological treatment.  相似文献   
9.
Diffuse large B-cell lymphoma (DLBCL) is the most frequent, complex and heterogeneous lymphoma of adulthood. Heterogeneity is expressed at clinical, genetic, and molecular levels. It is known that BCL-6 expression is a favorable prognostic factor in DLBCL. However, the underlying mechanisms of BCL-6 expression in DLBCL relapse are not yet elucidated. Here, we present so far undescribed clinical phenomenon of switching BCL-6+ protein expression into BCL-6 expression in 19 of 41 relapsed DLBCL patients. The switch in relapsed DLBCL was associated with more aggressive clinical course of the disease. Bone marrow infiltration and high IPI risk were more often present in BCL-6 patients. Significantly increased biochemical parameters, such as LDH, beta-2 macroglobulin, CRP, and ferritin have been found, as well as significantly decreased serum Fe, TIBC, and hemoglobin. A Ki-67 proliferation marker was considerably high in relapsed DLBCL, but without significant differences between BCL-6+ and BCL-6 groups of patients. Thus, switching of the positive into negative BCL-6 expression during DLBCL relapse could be used as a prognostic factor and a valuable criterion for treatment decision.  相似文献   
10.
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