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   713篇
  免费   93篇
  国内免费   17篇
耳鼻咽喉   3篇
儿科学   3篇
妇产科学   3篇
基础医学   119篇
口腔科学   23篇
临床医学   33篇
内科学   122篇
皮肤病学   2篇
神经病学   53篇
特种医学   23篇
外科学   40篇
综合类   46篇
预防医学   12篇
眼科学   12篇
药学   73篇
中国医学   28篇
肿瘤学   228篇
  2023年   41篇
  2022年   27篇
  2021年   62篇
  2020年   51篇
  2019年   39篇
  2018年   40篇
  2017年   25篇
  2016年   35篇
  2015年   71篇
  2014年   59篇
  2013年   58篇
  2012年   25篇
  2011年   24篇
  2010年   25篇
  2009年   17篇
  2008年   17篇
  2007年   14篇
  2006年   9篇
  2005年   6篇
  2004年   9篇
  2003年   12篇
  2002年   8篇
  2001年   12篇
  2000年   3篇
  1999年   11篇
  1998年   8篇
  1997年   5篇
  1996年   5篇
  1995年   9篇
  1994年   8篇
  1993年   4篇
  1992年   4篇
  1991年   6篇
  1990年   3篇
  1989年   3篇
  1987年   7篇
  1986年   4篇
  1985年   5篇
  1984年   6篇
  1983年   3篇
  1982年   4篇
  1981年   4篇
  1979年   6篇
  1978年   6篇
  1977年   3篇
  1976年   4篇
  1974年   3篇
  1973年   2篇
  1972年   2篇
  1970年   3篇
排序方式: 共有823条查询结果,搜索用时 359 毫秒
1.
PurposeTo investigate the reproducibility of diffusion-weighted (DW) MRI and 18F-Fluorodeoxyglucose (18F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.Materials and methodsTen women (median age, 67 years; range: 41.8–77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥ 1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients × 5 sites × 3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).ResultsFor both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained > 0.8 for PET/CT. Inter- and intra-observer ICCs were > 0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013–0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P = 0.0023, P< 0.0001 and P =0.0028, respectively).ConclusionWhile both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy.  相似文献   
2.
Growing evidence suggests that activated immune cells undergo metabolic reprogramming in the regulation of the innate inflammatory response. Remarkably, macrophages activated by lipopolysaccharide (LPS) induce a switch from oxidative phosphorylation to aerobic glycolysis, and consequently results in release of proinflammatory cytokines. Pyruvate Kinase M2 (PKM2) plays a vital role in the process of macrophage activation, promoting the inflammatory response in sepsis and septic shock. Deoxyelephantopin (DET), a naturally occurring sesquiterpene lactone from Elephantopus scaber, has been shown to counteracts inflammation during fulminant hepatitis progression, but the underlying mechanism remains unclear. Here, we studied the function of the DET on macrophage activation and investigated the anti-inflammatory effects of DET associated with interfering with glycolysis in macrophage. Our results first demonstrated that DET attenuates LPS-induced interleukin-1β (IL-1β) and high-mobility group box 1 (HMGB1) release in vitro and in vivo and protected mice against lethal endotoxemia. Furthermore, DET decreased the expression of pyruvate dehydrogenase kinase 1 (PDK1), glucose transporter 1(GLUT1), lactate dehydrogenase A (LDHA), and reduced lactate production dose-dependently in macrophages. Moreover, we further revealed that DET attenuates aerobic glycolysis in macrophages associated with regulating the nuclear localization of PKM2. Our results provided a novel mechanism for DET suppression of macrophages activation implicated in anti-inflammatory therapy.  相似文献   
3.
目的:观察脂多糖(lipopolysaccharide,LPS)诱导肺成纤维细胞及肺组织有氧糖酵解关键酶6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶3(6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3,PFKFB3)表达及其与有氧糖酵解的关系,探讨在LPS诱导肺纤维化过程中肺成纤维细胞和肺组织有氧糖酵解的潜在机制。方法:将人胚肺成纤维细胞MRC-5细胞系采用随机数字表法分为PBS对照组(PBS组)和LPS组(每组3孔),Western blot检测LPS刺激细胞6h后PFKFB3表达情况,同时免疫荧光显示PFKFB3在细胞内的定位情况;于LPS刺激后48 h采用海马细胞能量代谢仪检测细胞耗氧率(oxygen consumption rate,OCR)和产酸率(extracellular acidification rate,ECAR),并采用比色法检测有氧糖酵解产物乳酸产生情况,同时Western blot检测LPS刺激48 h后Ⅰ型胶原蛋白合成情况。将24只C57BL/6小鼠按随机数字表法分为生理盐水对照组(C组)、LPS组(L组),每组12只,L组、C组连续5d分别腹腔注射5 mg/kg LPS、等容量生理盐水;每组各6只于造模后第7天无痛处死小鼠,取血浆和肺组织,Western blot和免疫荧光检测各组肺组织中PFKFB3表达情况,比色法检测各组小鼠血浆中乳酸的含量;剩余小鼠于造模后第28天取肺组织,一侧肺通过Western blot检测肺组织Ⅰ型胶原蛋白合成情况,另一侧肺做石蜡切片进行病理学检测。结果:与PBS组比较,LPS刺激细胞6h后PFKFB3表达明显升高(P<0.05);LPS刺激细胞48 h后,与PBS组比较,LPS组细胞耗氧率降低、产酸率增加,代谢产物乳酸含量明显升高(P<0.05),同时细胞Ⅰ型胶原蛋白合成显著增加(P<0.05)。与C组比较,L组小鼠腹腔注射LPS 7 d后肺组织中PFKFB3表达明显升高(P<0.05),血浆乳酸含量明显升高(P<0.05);LPS注射28 d后,L组小鼠Ⅰ型胶原蛋白表达明显升高(P<0.05),肺组织出现明显纤维化。结论:在LPS诱导的肺纤维化过程中,LPS可诱导肺成纤维细胞和肺组织中PFKFB3蛋白表达,该过程与其有氧糖酵解过程相关,PFKFB3的表达上调可能是LPS诱导肺成纤维细胞和肺组织有氧糖酵解和肺纤维化的关键环节。  相似文献   
4.
5.
6.
7.
In clear cell renal cell carcinoma (ccRCC), glycolysis is enhanced mainly because of the increased expression of key enzymes in glycolysis. Hence, the discovery of new molecular biomarkers for glycolysis may help guide and establish a precise system of diagnosis and treatment for ccRCC. Expression profiles of 1079 tumor samples of ccRCC patients (including 311 patients treated with everolimus or nivolumab) were downloaded from public databases. Proteomic profiles of 232 ccRCC samples were obtained from Fudan University Shanghai Cancer Center (FUSCC). Biological changes, tumor microenvironment and prognostic differences were explored between samples with various glycolysis characteristics. There were significant differences in CD8+ effector T cells, epithelial-to-mesenchymal transition and pan-fibroblast TGFb between the Low and High glyScore groups. The tumor mutation burden of the Low glyScore group was lower than that of the High glyScore group. And higher glyScore was significantly associated with worse overall survival (OS) in 768 ccRCC patients (P < .0001). External validation in FUSCC cohort also indicated that glyScore was of strong ability for predicting OS (P < .05). GlyScore may serve as a biomarker for predicting everolimus response in ccRCC patients due to its significant associations with progression-free survival (PFS). And glyScore may also predict overall survival in patients treated with nivolumab. We calculated the glyScore in ccRCC and the defined glyScore was of strong ability for predicting OS. In addition, glyScore may also serve as a biomarker for predicting PFS in patients treated with everolimus and could predict OS in patients treated with nivolumab.  相似文献   
8.
Spermatozoa are highly specialized cells. Adenosine triphosphate (ATP), which provides the energy for supporting the key functions of the spermatozoa, is formed by 2 metabolic pathways, namely glycolysis and oxidative phosphorylation (OXPHOS). It is produced in the mitochondria through OXPHOS as well as in the head and principal piece of the flagellum through glycolysis. However, there is a great discrepancy as to which method of ATP production is primarily utilized by the spermatozoa for successful fertilization. Mitochondrial respiration is considered to be a more efficient metabolic process for ATP synthesis in comparison to glycolysis. However, studies have shown that the diffusion potential of ATP from the mitochondria to the distal end of the flagellum is not sufficient to support sperm motility, suggesting that glycolysis in the tail region is the preferred pathway for energy production. It is suggested by many investigators that although glycolysis forms the major source of ATP along the flagellum, energy required for sperm motility is mainly produced during mitochondrial respiration. Nevertheless, some studies have shown that when glycolysis is inhibited, proper functioning and motility of spermatozoa remains intact although it is unclear whether such motility can be sustained for prolonged periods of time, or is sufficiently vigorous to achieve optimal fertilization. The purpose of this article is to provide an overview of mammalian sperm energy metabolism and identify the preferred metabolic pathway for ATP generation which forms the basis of energy production in human spermatozoa during fertilization.  相似文献   
9.
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