贮运条件对草莓主要色素成分稳定性的影响

草莓在贮藏和运输期间会产生褪色现象,花青素含量逐渐减少.为研究光照时间、温度、pH、金属离子对草莓花青素的影响,探索合适的加工与贮运条件,在花青素含量保持一致的情况下设置4种反应条件,探讨光照时间、温度、pH、金属离子对草莓花青素的影响.草莓花青素在自然光下照射8 h,吸光度值下降25％,温度高于60℃后,吸光度值下降...     

土壤重金属污染及修复方法研究进展

为了解土壤重金属污染现状、各种修复方法的研究动态以及未来重金属的研究方向,笔者综述了土壤重金属的主要形态、污染程度评价指标、循环机制、离子间相互效应、修复方法等,并对今后的研究方向进行展望,为其他研究者提供参考。结果表明：关于土壤重金属的基础性研究还有待于进一步地深入和发展,特别是重金属的循环机制;重金属修复以植物和微生物修复为主体,其他修复方法并用将是趋势。     

Effect of compound salvae-dropping-pill on intracellular free calcium concentration of cultured rat myocardial cells in case of hypoxia and reoxygenation

AIM:To examine the effect of compound salvae-dropping-pill (CSDP) on intracellular free calcium in cultured rat myocardial cells subjected to hypoxia and reoxygenation.METHODS:The Fluo- 3/AM was applied to probe intracellular calcium concentration and the fluorescent intensity was detected using laser confocal microscopy technique.RESULTS:Fluorescent intensity in hypoxia plus CSDP group was significantly lower (1 217.78±312.07) than that of hypoxia group (1 509±508.48), and the Fluorescent intensity of hypoxia/reoxygenation plus CSDP group was also markedly lower (1 567.91±577.61) than that of hypoxia/reoxygenation group (1 617.60±477.53).CONCLUSION:The cultured rat myocardial cells could be effectively protected by administration of CSDP in case of hypoxia and reoxygenation through decreasing the intracellular calcium concentration.     

外源甜菜碱对盐胁迫下大麦幼苗体内多胺和离子含量的影响

外源甜菜碱对200 mmol/L NaCl胁迫下大麦幼苗的伤害有显著的缓解效应,0.5～10.0 mmol/L的甜菜碱均可以有效抑制盐胁迫导致的叶片中MDA含量的上升,增加根系含水量与幼苗鲜重,降低植株体内Na+/K+比,尤以1 mmol/L甜菜碱的效应最明显。甜菜碱可以显著地提高盐胁迫下大麦幼苗根系多胺含量,促进叶片内腐胺与亚精胺向精胺的转化     

Influence of oral co-administration of a preparation containing calcium and magnesium and food on enrofloxacin pharmacokinetics

The objective of this study has been to determine the influence of food and ions on the pharmacokinetics of enrofloxacin (ENRO) in turkeys, administered per os at a dose of 10 mg/kg of body weight (b.w.). Co-administration of ENRO with ions or with food significantly retarded its absorption, and the interaction was more pronounced when the drug was given together with food. The bioavailability of ENRO was 65.78 ± 7.81% and 47.99 ± 9.48% with ions and food, respectively. The maximum concentration (C_max) in plasma of animals exposed to ions reached 0.87 ± 0.26 μg/ml in a t_max of 2.07 ± 0.76 h; in animals which were fed while medicated, the analogous parameters were 0.36 ± 0.13 μg/ml and 8.06 ± 3.08 h. The PK/PD analysis demonstrated that a decrease in the concentration of ENRO in turkeys’ blood due to the interaction with ions or food might impair the drug's clinical efficacy toward some pathogenic microorganisms in turkeys if a routine dose of 10 mg ENRO/kg b.w. is administered.     

盐胁迫下水稻叶绿素荧光特性与离子积累的相关性分析

以4个北方常规粳稻品种为材料,于孕穗期施加80 mmol/L的NaCl胁迫,测定了水稻叶片叶绿素荧光参数及体内离子含量的变化,以揭示盐胁迫下水稻离子积累与叶绿素荧光特性的相关性.结果表明,盐胁迫下水稻叶片最大荧光(Fm)、最大光化学量子效率(Fv/Fm)、光系统II的实际光合效率(PhiPSⅡ)、表观光合量子传递效率(...     

一种弱电解质溶液无限稀释摩尔电导率的方法

依据Kohlrausch离子独立运动定律的基本原理,采用经典的电化学实验方法,测定强电解质溶液的无限稀释摩尔电导率,间接求出弱电解质溶液的无限稀释摩尔电导率。从而设计出一种测定弱电解质溶液无限稀释摩尔电导率的实验方法,应用于物理化学实验教学。该实验方法简便,结果准确。     

森林空气负离子及其主要影响因子的研究进展

空气负离子被称为"空气维生素和生长素",对人体健康十分有益.随着森林旅游事业的蓬勃发展,森林空气负离子的研究逐步成为热点问题之一.本文从森林空气负离子的概念、产生机理、影响森林空气负离子的主要环境因子、空气负离子在森林旅游区的应用等方面进行了综述,探讨了未来空气负离子研究与开发的重点方面.目的是促进森林空气负离子的研究与发展.     

两种不同耐盐大麦根际中离子的分布特征

选用耐盐性较强的大麦滩引５号（Ｔ）和盐敏感大麦ＣＴ１６（Ｓ），用根袋法研究了大麦极际中各种盐分离子的分布特征及动态变化。Ｔ大麦土体的ｐＨ高于Ｓ大麦，根际则相反。与非根际比较，Ｔ大麦根际土壤中除Ｋ＾＋离子亏缺外，Ｎａ＾＋，Ｃａ＾２＋，Ｍｇ＾２＋，ＳＯ４＾２－，Ｃｌ＾－及ＨＣＯ３＾－离子均富集；而Ｓ大麦根际土壤中Ｋ＾＋和Ｎａ＾＋离子亏缺，其它离子则不同程度地富集，但除ＨＣＯ３＾－离子外，亏缺或富集的程     

A novel technique for drying soil samples

Abstract

Evaporation rates and drying times of soil samples exposed to high fluxes of unipolar air ions of either polarity, produced by corona electrodes, were studied with a beta‐ray gauge. Ion‐treated soils dried more than three times faster than the control samples under the same laboratory conditions. An analysis of the experimental curves on Rideau clay showed evaporation rates of 2.96 x 10^‐4and 8.84 x 10^‐4g cm^‐2min^‐1for control and treated samples, respectively, when exposed to 4.39 x 10¹²negative air ions cm^‐2s^‐1. An objective criterion was defined for a state of soil dryness when the sample acquired a steady‐state value of transmission of beta particles with time. Electric wind caused by the ionic drag is proposed as the principal driving force for the enhancement of evaporation rates from soil samples used.