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   676篇
  免费   40篇
  国内免费   3篇
  719篇
  2023年   3篇
  2022年   13篇
  2021年   27篇
  2020年   15篇
  2019年   9篇
  2018年   15篇
  2017年   10篇
  2016年   20篇
  2015年   35篇
  2014年   42篇
  2013年   44篇
  2012年   68篇
  2011年   63篇
  2010年   41篇
  2009年   24篇
  2008年   57篇
  2007年   47篇
  2006年   32篇
  2005年   26篇
  2004年   45篇
  2003年   21篇
  2002年   20篇
  2001年   4篇
  2000年   2篇
  1999年   2篇
  1998年   4篇
  1997年   3篇
  1996年   6篇
  1995年   3篇
  1994年   2篇
  1993年   2篇
  1992年   4篇
  1991年   4篇
  1990年   1篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1979年   1篇
排序方式: 共有719条查询结果,搜索用时 15 毫秒
1.
Three underutilized leafy vegetables Sarcochlamys pulcherrima (Roxb.) Gaudich (SP), Ipomoea aquatica Forssk. (IA) and Zanthoxylum rhetsa (Roxb.) DC (ZR) were extracted with different solvents viz. 95 % ethyl alcohol, methanol and hot water. The extracts were evaluated for their antioxidant potential via DPPH, ABTS and FRAP assay along with electroanalytical studies using cyclic voltammetry. The antidiabetic potential was determined by recording their α-amylase and α-glucosidase inhibitory assay. The total phenolic content (TPC), total flavonoid content (TFC) and the liquid chromatography-mass spectrometry (LC/MS) based phytochemical profiles of the extracts were also determined. All three extracts of SP exhibited significant antioxidant capacity. The antidiabetic potential of the IA and ZR extracts was found to be higher than or at par with that of standard acarbose. LC/MS studies reveal the presence of hitherto reported antioxidant and antidiabetic compounds like gamma-aminobutyric acid, cinnamic acid, caffeic acid, α-viniferin, piperlonguminine, niacin, kaempferol, etc., in the extracts.  相似文献   
2.
3.

Background

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited disease. It is relatively recent that type 2C was identified as a separate group solely presenting with pheochromocytomas. As an illustration, an interesting case is presented of a pregnant woman with refractory hypertension. It proved to be the first manifestation of bilateral pheochromocytomas. The family history may indicate the diagnosis, but only identification of a germ line mutation in the DNA of a patient will confirm carriership.

Case presentation

A 27 year pregnant patient with intra uterine growth retardation presented with hypertension and pre-eclampsia. Magnetic resonance imaging revealed bilateral adrenal pheochromocytoma. She underwent laparoscopic adrenelectomy and a missense mutation (Gly93Ser) in exon 1 of the VHL gene on chromosome 3 (p25 - p26) was shown in the patient, her father and her daughter confirming the diagnosis of VHL.

Conclusion

In almost all VHL families molecular genetic analysis of DNA will demonstrate an inherited mutation. Because of the involvement in several organs, periodic clinical evaluation should take place in a well coordinated, multidisciplinary setting. VHL disease can be classified into several subtypes. VHL type 2C patients present with pheochromocytomas without evidence of haemangioblastomas in the central nervous system and/or retina and a low risk of renal cell carcinoma. Therefore, in such families, periodic clinical screening can be focussed on pheochromocytomas.  相似文献   
4.
Coronary artery disease (CAD) affects Indians 5–6 years earlier than in the west, is diffuse and malignant, and poses a heavy burden on India’s developing economy. Traditional risk factors have failed to explain this high incidence of premature CAD and hence this study investigated the association of two novel risk biomarkers, cystatin C and small dense LDL (sdLDL) with the presence and severity of CAD. Cystatin C and sdLDL were estimated in 204 CAD patients ≤45 years of age and compared with 161 age-matched healthy controls. The traditional lipid profile parameters, i.e., cholesterol, LDL, HDL, triglycerides, apolipoproteins A1 and B, and Lp(a) were also measured in both groups. Cystatin C was significantly raised and mean LDL particle size significantly reduced in CAD patients as compared to controls. 62.7 % of CAD patients showed pattern B while 37.3 % patients showed pattern A. Of the traditional lipid tests, only HDL and apolipoprotein A1 showed a significant decrease in the CAD group. sdLDL was significantly associated with the severity of CAD, while cystatin C was not. Both cystatin C and sdLDL emerged as independent risk factors, however, of the two, sdLDL was a more sensitive predictor of CAD events. Cystatin C and mean LDL particle size are significantly and independently associated with the presence of CAD events in patients ≤45 years with normal kidney function. Hence, these novel risk biomarkers can be useful tools in reducing the morbidity and mortality associated with CAD in the productive Indian workforce.  相似文献   
5.
This report describes a transfection-independent system for packaging alphavirus replicon vectors using modified vaccinia virus Ankara (MVA) vectors to express all of the RNA components necessary for the production of Venezuelan equine encephalitis (VEE) virus replicon particles (VRP). Infection of mammalian cells with these recombinant MVA vectors resulted in robust expression of VEE structural genes, replication of the alphavirus vector and high titers of VRP. In addition, VRP packaging was achieved in a cell type (fetal rhesus lung) that has been approved for the manufacturing of vaccines destined for human use.  相似文献   
6.
Starting from HTS hit 1a, X-ray co-crystallization and molecular modeling were used to design potent and selective inhibitors of PI3-kinase. Bioavailablity in this series was improved through careful modulation of physicochemical properties. Compound 12 displayed in vivo knockdown of PI3K pharmacodynamic markers such as pAKT, pPRAS40, and pS6RP in a PC3 prostate cancer xenograft model.  相似文献   
7.
Rap1 GTPase activation by its cAMP responsive nucleotide exchange factor Epac present in endothelial cells increases endothelial cell barrier function with an associated increase in cortical actin. Here, Epac1 was shown to be responsible for these actin changes and to colocalize with microtubules in human umbilical vein endothelial cells. Importantly, Epac activation with a cAMP analogue, 8-pCPT-2'O-Me-cAMP resulted in a net increase in the length of microtubules. This did not require cell-cell interactions or Rap GTPase activation, and it was attributed to microtubule growth as assessed by time-lapse microscopy of human umbilical vein endothelial cell expressing fluorophore-linked microtubule plus-end marker end-binding protein 3. An intact microtubule network was required for Epac-mediated changes in cortical actin and barrier enhancement, but it was not required for Rap activation. Finally, Epac activation reversed microtubule-dependent increases in vascular permeability induced by tumor necrosis factor-alpha and transforming growth factor-beta. Thus, Epac can directly promote microtubule growth in endothelial cells. This, together with Rap activation leads to an increase in cortical actin, which has functional significance for vascular permeability.  相似文献   
8.
Human Ecology - We address two aspects of forest lives—violence and care—that are central to forest outcomes but often invisible in mainstream discussions on forests. We argue that...  相似文献   
9.
Damage to proximal tubules due to exposure to toxicants can lead to conditions such as acute kidney injury (AKI), chronic kidney disease (CKD) and ultimately end-stage renal failure (ESRF). Studies have shown that kidney proximal epithelial cells can regenerate particularly after acute injury. In the previous study, we utilized an immortalized in vitro model of human renal proximal tubule epithelial cells, RPTEC/TERT1, to isolate HRTPT cell line that co-expresses stem cell markers CD133 and CD24, and HREC24T cell line that expresses only CD24. HRTPT cells showed most of the key characteristics of stem/progenitor cells; however, HREC24T cells did not show any of these characteristics. The goal of this study was to further characterize and understand the global gene expression differences, upregulated pathways and gene interaction using scRNA-seq in HRTPT cells. Affymetrix microarray analysis identified common gene sets and pathways specific to HRTPT and HREC24T cells analysed using DAVID, Reactome and Ingenuity software. Gene sets of HRTPT cells, in comparison with publicly available data set for CD133+ infant kidney, urine-derived renal progenitor cells and human kidney-derived epithelial proximal tubule cells showed substantial similarity in organization and interactions of the apical membrane. Single-cell analysis of HRTPT cells identified unique gene clusters associated with CD133 and the 92 common gene sets from three data sets. In conclusion, the gene expression analysis identified a unique gene set for HRTPT cells and narrowed the co-expressed gene set compared with other human renal–derived cell lines expressing CD133, which may provide deeper understanding in their role as progenitor/stem cells that participate in renal repair.  相似文献   
10.
Shrubs belonging to Carissa genus (Apocyanaceae family) are potential sources of food, medicine and fuel, yet they are wallowing under obscurity and rarely been exploited. Edibility of the pulpy Carissa fruits is known to only a meagre few. Since antiquity, the stem, root bark, leaves, fruit and seed extracts have been used in folklore medication. Now, the emerging scientific investigations are validating the ethno-medicinal uses of these species. Bioactive compounds which include viz. polyphenolics, flavonoids, flavanones, lignans and sesquiterpenes imparting therapeutic potential to these species have been isolated. In vitro and in vivo studies have shown these species to have antioxidant, analgesic, anti-inflammatory, hypolipidemic, wound healing, antimicroabial, antidiabetic, antiepileptic, anticancer, diuretic, nephrotoxicity amelioration and hepatoprotective activity. This miraculous plant extract has also been effective in the management of veterinary ailments. Apart from the medicinal attributes, this genus also holds promise as a suitable alternative crop for harvesting renewable energy. Micropropagtion is being tried for rapid multiplication of the valuable species. This review summarizes the recent findings for promoting the versatility of this genus.  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