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冻融作用对湿地土壤氨氮、硝氮以及解性有机碳的吸附解吸作用的影响(主要研究以溶解性有机碳为主),对深入研究季节性冻融区营养元素循环具有重要意义.本文以三江平原岸边湿地、环形湿地和农田湿地表层为研究对象,通过室内模拟实验,研究冻融作用对温地土壤冻融后溶解性有机碳吸附解吸强度影响;不同浓度梯度溶解性有机碳对湿地土壤冻融后碳吸附解吸强度影响.研究结果表明,冻融作用对湿地土壤碳的吸附解吸有所抑制.吸附量随冻融周期和所加溶液浓度的增加而增加,并且与土壤的理化性质具有一定的相关性.  相似文献   

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Retinal diseases are significant by increasing problem in every part of the world. While excellent treatment has emerged for various retinal diseases, treatment for early disease is lacking due to an incomplete understanding of all molecular events. With aging, there is a striking accumulation of neutral lipids in Bruch’s membrane. These neutral lipids leads to the creation of a lipid wall at the same locations where drusen and basal linear deposit, pathognomonic lesions of Age-related macular degeneration, subsequently form. High lipid levels are also known to cause endothelial dysfunction, an important factor in the pathogenesis of Diabetic Retinopathy. Various studies suggest that 20 % of Retinal Vascular Occlusion is connected to hyperlipidemia. Biochemical studies have implicated mutation in gene encoding ABCA4, a lipid transporter in pathogenesis of Stargardt disease. This article reviews how systemic and local production of lipids might contribute to the pathogenesis of above retinal disorders.  相似文献   

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Traditional recycling processes of LiCoO2 rely on destructive decomposition, requiring high-temperature roasting or acid leaching to extract valuable Li and Co, which have significant environmental and economic concerns. Herein, a direct repairing method for degraded LiCoO2 using a LiCl–CH4N2O deep eutectic solvent (DES) was established. The DES is not used to dissolve LiCoO2 but directly serves as a carrier for the selective replenishment of lithium and cobalt. Replenishment of lithium restores LiCoO2 at different states of charge to a capacity of 130 mAh/g (at 0.1 C rate), while replenishing the cobalt increases the capacity retention rate of 90% after 100 cycles, which is comparable to pristine LiCoO2. The DES is collected and reused multiple times with a high repair efficiency. This process reduces energy consumption by 37.1% and greenhouse gas emissions by 34.8% compared with the current production process of LiCoO2, demonstrating excellent environmental and economic viability.  相似文献   

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尹渭元  卢凤英 《科技通报》1994,10(3):182-185
进行了花粉保健食品花粉片与花粉营养液的动物与临床实验研究,结果表明,花粉片与花粉营养液有明显的降脂作用及抗动脉粥样硬化作用;该产品作为天然保健食品,具有多种营养与保健功能,并有预防中老年人动脉粥样硬化性心脑血管疾病的作用.  相似文献   

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造成中国春运难题的表层原因是客流集中和铁路运力不足,深层原因是城乡二元结构、春节情结和情感慰藉需要。文章探索破解春运难题的方法,认为治标的方法是修造铁路、错峰分流与构建立体运输网。治本的方法是反省亲、消除城乡二元结构和平衡地区间的经济发展;并论述了提价不能解决春运难题的理由,提出解决春运难题应坚持的三个原则。  相似文献   

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程刚  单江  张勇  陈珊 《科技通报》2002,18(2):118-121
目的:分析冠心病患者和正常人血脂水平与心率变异频域指标及自主神经活动的关系。方法:对71例确诊的冠心病患者和96例正常人行24h动态心电图并采空腹血查血脂,分别比较两类人群中高胆固醇血症组与正常胆固醇组心率变异频域指标VLF、LF、HF、LF/HF的差异,并用多元逐步回归分析血脂各值与心率变异的相关性。结果:高胆固醇血症组与正常胆固醇组相比,冠心病患者中HF值显著降低(P<0.05),而LF/HF值显著增高(P<0.01);正常人亦有高胆固醇血症组HF值较低而F/HF值较高的趋势,但无统计学差异。多元逐步回归分析中,冠心病患者HF与TC呈负相关,LF/HF则与TC、LDL呈正相关;正常人中LF/HF亦与TC呈正相关。结论:冠心病患者和正常人中血脂水平均与心率变异及自主神经活动存在一定的相关性。胆固醇增高者交感与迷走神经平衡性失调,交感神经活性相对较高而迷走神经活性相对较低。  相似文献   

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Erythrocyte membrane protein glycosylation increase by 3.4 fold in diabetes. Insulin or sulfonylurea treatment did not reduce the extent of glycosylation. The serum protein glycosylation was comparable in all the groups including control. Erythrocyte membrane Na+,K+-ATPase activity decreased in the diabetics; only insulin treatment partly restored the activity. Erythrocyte membrane acetylcholinesterase activity decreased only in the sulfonylurea treated group. Serum butyrylcholinesterase activity was relatively low in the diabetic and insulin treated diabetic groups. The Km and Vmax of the two components of Na+,K+-ATPase from erythrocyte membranes were differently affected in the diabetic and the two treatment groups. The Vmax of acetylcholinesterase decreased only in the sulfonylurea treated group. Diabetic states resulted in decreased Vmax of components I and II of serum butyrylcholinesterase. In insulin-treated diabetics, component II was absent. Sulfonylurea group resembled diabetics.In vitro incubation with insulin differentially affected the Na+,K+-ATPase and serum butyrylcholinesterase activities.  相似文献   

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Elevated plasma triglyceride and non-esterified fatty acid concentrations may cause insulin resistance and type 2 diabetes mellitus. Lipoprotein lipase (LPL) is a rate-determining enzyme in lipid metabolism. A variant in the LPL gene has been identified which alters the penultimate amino acid Serine at 447 to a stop codon (S447X), and results in a truncated LPL molecule lacking the C-terminal dipeptide Ser–Gly. The present study was designed to evaluate the frequency of S447X variant in the LPL gene and its effect on the lipid and lipoprotein levels in type 2 diabetic subjects. The genotype frequency distributions of type 2 diabetes patients and controls were in Hardy–Weinberg equilibrium. Comparison of the genotype and allelic frequencies of S447X in subjects with type 2 diabetics compared to controls demonstrated no significant difference. In subjects with type 2 diabetics having hypertriglyceridemia (TG ≥ 150 mg/dl) compared to diabetics with TG level <150 mg/dl, significant difference in genotype frequency was found among these groups, while allelic frequency of X was significantly differed. Logistic regression analysis showed the negative association of LPL S447X variant with TG and VLDL cholesterol, while no association with total cholesterol, HDL cholesterol and LDL cholesterol was found. The lipid levels except for HDL cholesterol were found to be significantly lower in carriers for S447X than wild type in diabetes group. The decreased level of TG and TG rich lipoprotein in subjects with SNP S447X in LPL, predicts anti-atherogenic activity of carriers for S447X variant in general population as well as type 2 diabetic patients.  相似文献   

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以引进名贵花卉一品红的茎段为外植体,接种于aMS+BA0.1;bMS+2,4-D1.5+BA0.2+NAA0.1;cMS+BA2+NAA0.1;dMS+BA2+IBA1;eMS+BA3+IBA2 PH值均为5.8的培养基上,进行离体培养,实验结果表明:一品红最适合的诱导分化培养基为d、MS+BA2+IBA1培养基。  相似文献   

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The question of exactly how science is commercialized is an important one. While the social structures of “science” and “technology” are distinctive, recent work suggests that scientific and technological ideas in fact co-evolve. This paper addresses the dynamics of such co-evolution: are scientific networks deeply co-mingled with networks through which technology is created and if so how? It does so in a study of an emerging area of biomedicine—tissue engineering. The research is based on a novel methodology that takes advantage of the fact that an idea is often inscribed in both a patent and paper, thus forming a patent–paper pair. Starting with the pair, it is possible to trace the citation network of patents, papers, inventors and authors, combining traditional bibliometric analysis with in-depth interviews to provide new insights. The results show that for this case there exist distinctive scientific and technological networks. Furthermore, while there is evidence of overlap, it is neither co-publishing nor citation as might be predicted from current literature. Rather co-mingling exists through founding, licensing, consulting and advising. This has implications for our understanding of the processes through which spillovers arise, the way in which commercialization and technology transfer should be structured and for recent debates on conflict of interest in biomedicine.  相似文献   

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In this special issue of Biomicrofluidics, a wide variety of applications of microfluidics to tissue engineering and cell biology are presented. The articles illustrate the benefits of using microfluidics for controlling the cellular environment in a precise yet high rate manner using minimum reagents. The topic is very timely and takes a stab at portraying a glimpse of what is to come in this exciting and emerging field of research.  相似文献   

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期间核查的实施及判定方法   总被引:1,自引:0,他引:1  
黄成芬 《大众科技》2013,(2):26-27,25
期间核查是对校准实验室和检测实验室的通用要求之一,计量标准的核查关系到该地区计量活动和检测结果的有效性和准确性。期间核查的本质是保持被核查仪器的校准状态,即核查其稳定性。文章讨论期间核查如何实施以及几种实用的期间核查方法。  相似文献   

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In this special issue of Biomicrofluidics, many manifestations of biological microfluidics have been highlighted that have significance to regenerative biology and medicine. The collated articles demonstrate the applicability of these biological microfluidics for studying a wide range of biomedical problems most useful for understanding and shining light on basic biology to those applications relevant to clinical medicine.  相似文献   

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