青海枸杞叶总黄酮含量的测定

本文采用紫外分光光度法分析了青海枸杞叶中总黄酮的含量，结果表明，青海枸杞叶总黄酮含量较高。     

石墨炉原子吸收光谱法测定枸杞叶茶中铅的测定

本文以宁夏当地生产的枸杞叶茶为样品.试样经酸消解后,注入原子吸收石墨炉中,电热原子化后吸收2833nm共振线,在0～50ng浓度范围,其吸收值与铅含量成正比,与标准系列比较定量.     

互联网上的医学类免费全文电子文献资源

从图书资源、期刊资源、报纸资源、论文资源、会议资源、学位论文资源、标准资源和专利资源8种文献资源类型,对互联网上的医学类免费全文电子文献资源进行了探讨.     

论矿区资源绿色开发的资源科学基础

在论述我国矿产开发对矿区资源环境的影响、矿区资源绿色开发内涵及煤矿绿色开采技术体系基础上,讨论了现代资源科学在构建矿区资源绿色开发模式中的重要作用,分析了面向矿业系统进行资源科学学科人才培养的必要性.作者认为,我国矿区中存在的诸多问题,往往都源于矿产资源的不合理开发利用,矿区资源绿色开发研究中需解决的不少问题正是资源科学关注的领域,运用传统的地矿学科知识与思维难以构建矿区资源绿色开发模式,迫切需要具有整体理念的现代资源科学理论作指导,对自然资源系统进行综合性研究,集自然科学、社会科学和工程技术于一体进行系统研究,运用多学科知识进行交叉研究等特点,决定了面向矿业系统进行资源科学研究与人才培养很有必要、大有可为.     

以“三要素”为切入点解析高校图书馆资源利用

高校图书馆资源是高校开展各项服务的基础,文章从馆藏资源、环境资源、人力资源三要素对高校图书馆资源进行了概述,并对其利用现状及原因进行分析,最后针对性地提出了提高高校图书馆资源利用率的对策。     

科技资源共享的需求、内容、方法体系框架

科技资源是从事科技活动所需要的物质与信息资源,是提高企业协同创新能力的基础条件。科技资源共享可以提高科技资源的利用效率。本文建立了科技资源需求、内容、方法体系框架,包括：(1)科技资源共享需求体系,主要是高端化、个性化、绿色化和人性化需求。(2)科技资源内容体系,主要是知识、数据、产品、人才、软件、硬件等科技资源。(3)科技资源共享方法体系,对科技资源描述、集成、评价和分享方法的具体内容、相互关系进行了分析。科技资源共享是一个系统工程,需要对科技资源进行描述、集成和评价,在此基础上进行科技资源分享。本文的研究意义是：(1)对科技资源的内容、共享需求和共享方法的全面研究,有助于科技资源开放共享标准体系和信息平台的顶层设计。(2)将科技资源描述、集成、评价和分享作为一个高度关联的系统进行研究和实践,有助于解决科技资源共享难的问题。     

浅谈城建档案信息资源的开发与利用

城建档案作为社会信息资源的组成部分,也是一种技术资源、管理资源、决策资源。这就促使档案工作走向信息系统,要求我们把城建档案作为一种特有的信息资源进行开发、传递并利用。针对这一问题进行了论述。     

开发课程资源 提高语文素养

结合自己的教学实践,就如何创造性地理解和使用教材,积极开发课外学习资源,提高学生的语文素养进行初步探索,提出开发课程资源可从关注校园生活资源、日常生活资源、社会生活资源、现代视听技术及信息技术资源、地方特色文化资源和学科整合资源等方面努力。     

基于非本体资源重用重构的本体构建研究

要真正实现语义网,必须有丰富且及时更新的本体。为了加快本体开发速度、节约时间和资源、实现本体的及时更新,本体构建者开始重用非本体资源进行本体构建。文章首先对非本体资源进行了科学的定义和分类,接着概述了非本体资源重用、重构和重构非本体资源构建本体的模式目前的研究水平,并在此基础上提出了重用、重构非本体资源进行本体构建的全部流程,以求对利用非本体资源构建本体提供借鉴。     

开发课程资源 提高语文素养

结合自己的教学实践,就如何创造性地理解和使用教材,积极开发课外学习资源,提高学生的语文素养进行初步探索,提出开发课程资源可从关注校园生活资源、日常生活资源、社会生活资源、现代视听技术及信息技术资源、地方特色文化资源和学科整合资源等方面努力。     

千烟洲试验区湿地松人工林凋落叶及其营养元素动态分析

本文研究了千烟洲试区湿地松人工林凋落叶及其营养元素的数量动态特征。通过对该树种的凋落叶量分析。了解了该树种的凋落叶在各个时期中的不同特征，从而进一步加深了解凋落在森林中的功能地位。     

香榧树叶精油成分与化学分类

作者曾经证明香榧叶中具有特征成分榧黄素(kayaflavone)。最近，又从香榧叶中分得一 个新的二萜特征成分香榧酯(torreyagrandate)，为了获得更多的特征成分，我们自榧树叶中共鉴  定出26个精油成分。从组成比看，其特点是苧烯占优势(44．24％)，其次为 α-蒎烯(20．75％)，再次为δ-3-蒈烯(4％)。叶中所含的榧烯醇(torreyol)为特征成分。     

Post-mortem privacy and informational self-determination

Post-mortem privacy is becoming a vital topic of public and scholarly legal concern. Post-mortem privacy is understood as the right of a person to preserve and control what becomes of his reputation and dignity after death. The assumption that the deceased does not qualify for privacy rights, because his bodily presence has been terminated, no longer holds in our networked society. In the digital age, the phenomenon of the digital legacy that an Internet user leaves behind after his demise, has led to new challenges for the legal system. The deceased is no longer in a position to exercise human autonomy as an active agent. The article reconsiders the notion of human autonomy with regard to these digital representations. Taking the point of view that the control over personal information (also known as informational self-determination) is essential in protecting one’s privacy in the antemortem life, the article explores whether this principle may have validity in the postmortem context. Legal philosophical arguments are advanced in a discourse about the quandary if digital personae of deceased persons can be bestowed with a legal basis of personality rights and concomitantly privacy rights. Therefore much attention is given to the problem of the subject, which does not seem to be functioning in the case of the absence of a living subject. Briefly referring to novel personae, it is argued that fundamental human rights need not be limited to the rights of living human beings.     

测量系统分析(MSA)在烟草数字投影仪测量能力分析中的应用

为了解测量系统中各波动源大小及其对测量结果的影响程度,介绍测量系统能力分析RR等测量指标,并对实验室烟草数字投影仪的测量能力进行了测量系统分析评价。以烟草制丝加工过程中的叶丝宽度指标为例,应用测量系统分析评价实验室烟草数字投影仪测量能力,使用测量系统分析方法,分析MINITAB软件生成的结果,找出测量过程中的波动源和影响程度,为实验室烟草数字投影仪的使用提供帮助。     

Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures

BackgroundLycium barbarum (also called wolfberry), a famous Chinese traditional medicine and food ingredient, is well recognized for its significant role in preventing obesity; however, the molecular mechanisms underlying its preventive effects on fat accumulation are not well understood yet. The aim of this study was to determine the effects and mechanism of Lycium barbarum polysaccharides (LBP) on the proliferation and differentiation of 3T3-L1 preadipocytes. MTT was used to detect the proliferation of 3T3-Ll preadipocytes. Oil red O staining and colorimetric analysis were used to detect cytosolic lipid accumulation during 3T3-L1 preadipocyte differentiation. Real-time fluorescent quantitative PCR (qPCR) technology was used to detect peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), adipocyte fatty-acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL) expression.ResultsThe concentration of LBP from 25 to 200 μg/mL showed a tendency to inhibit the growth of preadipocytes at 24 h, and it inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. In the preadipocytes treated with 200 μg/mL LBP, there were reduced lipid droplets in the cytoplasm, and its effect was opposite to that of rosiglitazone (ROS), which significantly reduced the PPARγ, C/EBPα, aP2, FAS, and LPL mRNA expression of adipocytes.ConclusionsLBP exerts inhibitive effects on the proliferation and differentiation of 3T3-L1 preadipocytes and decreases the cytoplasm accumulation of lipid droplets during induced differentiation of preadipocytes toward mature cells. Above phenomenon might link to lowered expression of PPARγ, C/EBPα, aP2, FAS, and LPL after LBP treatment. Thus, LBP could serve as a potential plant extract to treat human obesity or improve farm animal carcass quality via adjusting lipid metabolism.How to cite: Xu X, Chen W, Yu S, et al. Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures. Electron J Biotechnol 2021;50. https://doi.org/10.1016/j.ejbt.2021.01.003     

金丝桃属植物叶中分泌结构的比较解剖学研究

利用整体透明法、石蜡制片法和半薄切片法，对金丝桃属9组43种l亚种1变种的植物叶分泌 结构的类型、形态、结构和分布进行了比较研究。结果表明，分泌结构是金丝桃属植物叶片普遍的结构特征，根据其分泌结构的特征，可划分为分泌细胞团、分泌囊(道)和韧皮部中分泌小管道等3种分泌结构。其中，分泌细胞团按其在叶片的分布可分为叶缘型和散生型；分泌囊按其在叶横切面中的位置可分为栅栏组织型、海绵组织型、居中型(位于栅栏组织型与海绵组织型之间)和横跨叶肉组织型。根据分泌囊和分泌细胞团在该属植物叶中的分布可划分为3种类型：(1)只有分泌囊的类型；(2)只有分泌细胞团的类型；(3)具分泌囊和分泌细胞团的类型。两种主要分泌结构的类型、分布密度、分布位置及其形态等方面在组间和种间均存在—定的差异，对金丝桃属属以下等级的区分具有一定意义。在此基础上，对该属分泌结构的形态演化以及金丝桃属各组间的亲缘关系进行了探讨。     

Does Chewing Coca Leaves Influence Physiology at High Altitude?

Andean Indians have used coca leaves (Erythroxylon coca and related species) for centuries to enhance physical performance. The benefits and disadvantages of using coca leaf have been a subject of many political debates. The aim of this study was to investigate the effects of chewing coca leaves on biochemical and physiological parameters. Cutaneous microdialysis catheters were used to estimate systemic biochemical changes. We subjected 10 healthy adult males (local residents) in Cajamarca (Peru, altitude 2700 m) to a standardised exercise routine on a stationary cycle ergometer. The blood pressure, oxygen saturation (digital), pulse, VO2 max and ECG (Holter monitor) were recorded before the exercise. Cutaneous microdialysis catheters were introduced in the forearm. The subjects were given to chew 8 g of coca leaves with a small amount of lime. They were then placed on the cycle ergometer for 20 min. Blood pressure, oxygen saturation, pulse, ECG and VO2 max were recorded. Pyruvate, glucose, lactate, glycerol and glutamate levels were estimated. Oxygen saturation, blood pressure, and pulse rate did not show any significant changes between the two groups. Glucose levels showed hyperglycaemic response. Glycerol, Lactate and Pyruvate increased. Glutamate remained unchanged. Similar changes were not seen in the controls. These results suggest that coca leaves have blocked the glycolytic pathway of glucose oxidation resulting in accumulation of glucose and pyruvate. The energy requirement for exercise is being met with beta-oxidation of fatty acids. The glycerol released was also getting accumulated since its pathway for oxidation was blocked. These experimental findings suggest that chewing coca leaves is beneficial during exercise and that the effects are felt over a prolonged period of sustained physical activity.     

植物叶片表面温度的热电偶测量

植物叶片是植物的主体部分,植物叶片的自身温度可以体现出植物的生长状态。本文针对目前红外测温技术在植物叶片表面温度测量中存在的缺陷,提出并设计了基于铂热电偶贴片式传感器的植物叶片表面温度测量装置,采用接触式测量方法实现了对植物叶面温度的测量,并采用水浴法对测温装置进行了标定。     

植被护坡稳定性研究分析

随着我国公路、铁路、水库等的兴建,对边坡的稳定与生态环境保护有机结合的要求也越来越高。传统的护坡方式虽有较好的护坡能力,但对生态环境的破坏是非常严重的,已经不能与现在对生态坏境保护的需求相适应。随之被广泛应用的是植被护坡,它既有较好的护坡能力,又能使工程对生态坏境的破坏达到最小。本文将从植被对地表土颗粒流失的约束作用、植被根系对土体的加筋效应、植被枝叶对降雨的导流减冲作用等几方面对植被护坡的稳定性进行研究分析。     

中国木兰科植物的叶结构及其油细胞的比较解剖学研究

利用组织透明法、石蜡切片法及薄切片法对木兰科10属82种1亚种植物叶片的结构和油细胞的 分布密度、结构及其在叶肉中的分布进行了比较研究。鹅掌楸亚科和木兰亚科在叶结构上的主要区别是：鹅掌楸亚科两种植物叶的部分下表皮细胞乳突状,且整个细胞外壁只形成一个乳突,而在木兰亚科植物中有单列多细胞或单细胞的表皮毛,却未发现乳突;鹅掌楸亚科植物叶主脉维管组织环分隔呈束状,且其外包被的纤维也排列成束状,而木兰亚科的80种1亚种植物中,叶主脉维管组织连成轮状,其外面也由一圈连续的纤维环所包围。从而支持木兰科中木兰亚科和鹅掌楸亚科两个亚科的划分。并且,从叶主脉的演化趋势来看,鹅掌楸亚科较木兰亚科进化。另外,木莲属植物叶片的结构与木兰属具有明显差异,因而进一步证明木莲属是不同于木兰属的一个独立的属。油细胞是木兰科植物叶片解剖的显著特征,在叶肉中的分布可划分为3种类型：(A)主要分布于栅栏组织;(B)主要分布于海绵组织;(c)均匀散布于整个叶肉中。油细胞的大小及其在叶中的分布与叶厚、栅栏组织层数、栅栏组织与海绵组织厚度间的比值以及下皮层的有无、表皮毛的类型、叶脉的结构等特征相结合,可作为属、甚至种的鉴别特征。