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.     

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.     

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。     

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...     

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.     

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。     

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     

Effects of dissolved oxygen on hemolymph parameters of freshwater giant prawn, Macrobrachium rosenbergii (de Man)

Profiles of changes in physiological parameters of freshwater giant prawns, Macrobrachium rosenbergii, exposed to various dissolved oxygen (DO) levels of 7.75, 4.75, 2.75, and 1.75 mg l⁻¹ are reported. The parameters involved in osmoregulation and oxygen transport were monitored for a 6-day period. Notable depressions in hemolymph osmolality, Na⁺, K⁺, and Cl⁻ contents were observed within 24 h after exposure to hypoxia at 2.75 and 1.75 mg O₂ l⁻¹, and thereafter remained at rather steady levels, which were significantly lower than those under normoxic conditions (4.75–7.75 mg O₂ l⁻¹). The extent of depression of osmotic-related constituents, hemolymph osmolality and Cl⁻ in particular, increased with decreased DO.

Oxyhemocyanin constituted 65.46–65.84% of total hemolymph proteins under the various DO levels examined; both hemolymph oxyhemocyanin and proteins showed notable elevations 24 h after exposure to hypoxic conditions, and reached the highest and constant level by 48 h after exposure. The compensatory responses of prawns to reduced O₂ were manifested by increased O₂ uptake through augmentation of hemocyanin, which results in enhancement of oxygen binding capacity of the hemolymph. In the same period, a significant surge of the respiratory products, PCO₂ and HCO₃⁻, was also demonstrated 6 h after exposure to hypoxic conditions which resulted in hemolymph alkalosis. These processes likely resulted in an increase in water influx and consequent declines in hemolymph osmolality and ion composition. Furthermore, hyperventilation and respiratory alkalosis, indicated by increased oxyhemocyanin and pH, respectively, were found to be predominant responses of M. rosenbergii to hypoxic stress.     

Different concentrations of intracellular calcium in uterine myometrial cells at term and non-term

AIM:To investigate different intracellular concentration of Ca²⁺ in uterine myometrial cells at term and non-term.METHODS:The living cells suspensions were made to measure intracellular Ca²⁺ concentrations after stainned by calcium fluorescent indicator Fluo-3 AM, then examined by laser scanning confocal microscope (LSCM).RESULTS:Intracelluar Ca²⁺ showed very stronger red positive signal in myometrial cells at term than that in non-term cells. [Ca²⁺]i were (35±8.1) nmol/L at non term and (75±7.3) nmol/L at term, which had significant difference compared with each other (P＜0.05).CONCLUSION:Increase in [Ca²⁺]i in myometrial cells might play a very important role labor.