Cytoprotective effects of geraniin against peroxynitrite- and peroxyl radical-induced cell death via free radical scavenging activity

The role of natural antioxidants in combating the deleterious effects of free radicals has received much attention. In the present study, the cytoprotective effects and the free radical scavenging activity of geraniin, a hydrolysable ellagitannin from Nephelium lappaceum rind, were evaluated by using various approaches. Addition of geraniin to the culture media resulted in a profound cytoprotective effect against damages induced by the peroxynitrite generator 3-morpholinosydnonimine (SIN-1), and the peroxyl radical generator 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). Geraniin exhibits more potent cytoprotective activity than that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). Geraniin exhibited potent antioxidant activity against reactive species, such as nitric oxide, superoxide anion, and chemically synthesized peroxynitrite. Kinetic analysis of reactivity against peroxyl radicals generated by AAPH revealed that geraniin possesses potent reactivity against peroxyl radicals with higher stoichiometric number than Trolox. The cytoprotective effect of geraniin was only observed when geraniin and these toxic compounds were co-existing, suggesting that geraninn exhibits cytoprotective effects via free radical scavenging activity in the extracellular fluid.     

Temporal dynamics and response to fogging or fumigation of stored-product Coleoptera in a grain processing facility

Stored-product Coleoptera were monitored continuously over 22 months using pitfall traps at an operating food mill and adjacent warehouse in Kansas. Mill management practiced conventional pest management, including monthly crack and crevice applications of a residual insecticide and semi-annual fumigation with methyl bromide in the mill, and application of dichlorvos+pyrethrin (commonly called fogging) in the warehouse. The dynamic temporal changes in insect captures and effect of the global interventions on insect captures were analyzed. Data show that more Trogoderma variabile individuals were captured in the warehouse than any other species, but Tribolium castaneum was captured with greater frequency. Trogoderma variabile captures inside the warehouse tended to mirror outside captures suggesting immigration from the outside. The food mill was infested year round with T. castaneum but developed substantial populations of Typhaea stercorea during the warm months from May through October. Stored-product insects were nearly always captured during the first trapping interval following methyl bromide or dichlorvos+pyrethrin applications, but it was not clear if the insects were surviving inside the structure or if they were rapidly recolonizing after treatment. Population increases immediately following fumigation or fogging occurred only in fungus-feeding species in late spring or summer. The most successful fumigation was conducted late in the autumn when environmental conditions prevented insect activity outside. Information contained in this study provides data that could be used to improve insect management programs for milling and processing facilities.     

溴化锂吸收式冷水机组及其性能测试软件的研究

介绍了直燃型、蒸汽型和热水型3种形式的溴化锂吸收式冷水机组,依据相关的国家标准编程开发了性能测试软件,分析了软件的特点及需要改进的地方,展望了该软件的应用前景.     

Numerical modelling of a bromide-polysulphide redox flow battery. Part 2: Evaluation of a utility-scale system

Numerical modelling of redox flow battery (RFB) systems allows the technical and commercial performance of different designs to be predicted without costly lab, pilot and full-scale testing. A numerical model of a redox flow battery was used in conjunction with a simple cost model incorporating capital and operating costs to predict the technical and commercial performance of a 120 MWh/15 MW utility-scale polysulphide-bromine (PSB) storage plant for arbitrage applications. Based on 2006 prices, the system was predicted to make a net loss of 0.45 p kWh⁻¹ at an optimum current density of 500 A m⁻² and an energy efficiency of 64%. The system was predicted to become economic for arbitrage (assuming no further costs were incurred) if the rate constants of both electrolytes could be increased to 10⁻⁵ m s⁻¹, for example by using a suitable (low cost) electrocatalyst. The economic viability was found to be strongly sensitive to the costs of the electrochemical cells and the electrical energy price differential.     

松香丙烯酸加成物的溴化

利用松香中的左旋海松酸与丙烯酸进行D-A双烯加成反应,制成松香丙烯酸加成物（RA）,再将其与液溴反应,制成溴化物（BRA）.利用红外光谱、核磁共振和元素分析表征了RA、BRA的分子结构,紫外光谱表征了产物中双键吸收峰的变化,热重和示差扫描量热法表征了产物的热分解性能,燃烧试验测试了产物的阻燃性能.实验表明,BRA失重10%和50%时的温度与RA相比,分别下降了32.3和5.8℃,分解温度范围变宽且难以燃烧,是一种较好的阻燃材料.     

文新大厦供暖制冷机房设计

介绍了采用直燃式（燃气）溴化锂机组在机房设计中应注意的问题及所采取的安全措施。     

CAPILLARY ELECTROKINETIC SEPARATION OF POLYCYCLIC AROMATIC HYDROCARBONS USING CETYLPYRIDINIUM BROMIDE

Polycyclic aromatic hydrocarbons (PAHs) including isomeric pairs were separated in capillary electrokinetic chromatography using a cationic surfactant cetylpyridinium bromide (CPBr) as additive. With addition of 2 mM CPBr into the running electrolyte, dynamic coating occurs in the capillary and EOF is reversed. Changes of electroosmotic and electrophoretic mobilities with increasing CPBr concentration were investigated. Under optimum separation conditions, running electrolyte contains 50% MeCN, 20 mM acetate, and 40 mM CPBr at pH = 4.0. Using high concentration of organic solvent, aggregation of surfactants into micelles is prevented. Significant retentions indicate solvophobic, n- and π-electron interactions between CPBr monomers and PAHs.     

ADSORPTION OF TOLUENE ON BENTONITES MODIFIED BY DODECYLTRIMETHYLAMMONIUM BROMIDE

The adsorption of toluene was studied by using various types of adsorbents (Na⁺- and Al³⁺-bentonite) modified by dodecyltrimethylammonium bromide (DTAB). The characterization of these new sorbing matrices by XRD and IR indicates that DTAB tallow interacted with bentonite and increased the interlayer spacing of the clay with double-layered formation. Adsorption of toluene on modified bentonites was characterized by linear isotherms with no limitation of adsorption within the concentration range studied, thus indicating a mechanism of adsorption due to partition. Adsorption was fast and favored by a slightly acid medium. Pseudo-first-order, pseudo-second-order, the Elovich equation, and intra-particle diffusion models were used to fit the experimental data. The adsorption kinetic of toluene was described by the pseudo-first order onto DTAB-Na-bent, and pseudo-second order onto DTAB-Al-bent. The intra-particle diffusion process was identified as the main mechanism controlling the rate of toluene adsorption. Thermodynamic parameters such as standard free energy change (ΔG ⁰), the standard enthalpy change (ΔH ⁰), and the standard entropy (ΔS ⁰) were also evaluated. The variation of adsorption energy versus the types of adsorbent suggested a physical adsorption mechanism.     

苯乙烯磺酸钠的烯基活性的分析

利用溴化技术用容量法测定苯乙烯磺酸钠中的烯基活性,并进行了结果分析。     

A water-activated cuprous bromide battery

In this work a water-activated copper(I) bromide battery was developed and investigated. CuBr combined with sulphur as the reactive cathode material was compared with the CuCl-sulphur combination, the anode being in both cases a magnesium alloy. Battery characteristics were tested at room temperature and in an atmosphere simulation chamber because water-activated batteries are mostly used in meteorological radiosondes. Heat evolution was studied calorimetrically, and the potentials of the single electrodes were measured in half-cell experiments. The practical voltages remained significantly lower than the theoretical ones. The low actual voltages of the batteries were found to be caused by the potential loss at the magnesium anode. The heat evolution power of the CuBr battery was approximately 20% lower than the power of the CuCl battery as a result of bromide ions that catalyse the exothermic corrosion reaction of magnesium less than chloride ions. The CuBr battery is environmentally preferable to the CuCl battery because the reaction that produces harmful Cu²⁺ ions does not progress with CuBr. The problem when using CuBr is the slow activation, which can be accelerated by adding soluble salts to increase the conductivity of the electrolyte.