Triphenylphosphonium (TPP)-Based Antioxidants: A New Perspective on Antioxidant Design

Mitochondrial oxidative damage and dysfunction contribute to a wide range of human diseases. Considering the limitation of conventional antioxidants and that mitochondria are the main source of reactive oxygen species (ROS) which induce oxidative damage, mitochondria-targeted antioxidants which can selectively block mitochondrial oxidative damage and prevent various types of cell death have been widely developed. As a lipophilic cation, triphenylphosphonium (TPP) has been commonly used in designing mitochondria-targeted antioxidants. Conjugated with the TPP moiety, antioxidants can achieve more than 1000-fold higher mitochondrial concentration depending on cell membrane potentials and mitochondrial membrane potentials. Herein we discuss the deficiencies of conventional antioxidants and the advantages of mitochondrial targeting, and review various types of TPP-based mitochondria-targeted antioxidants. These provide theoretical and background support for the design of new anti-oxidant.     

Bag filters for TPP

Cleaning of TPP flue gases with bag filters capable of pulsed regeneration is examined. A new filtering element with a three-dimensional filtering material formed from a needle-broached cloth in which the filtration area, as compared with a conventional smooth bag, is increased by more than two times, is proposed. The design of a new FRMI type of modular filter is also proposed. A standard series of FRMI filters with a filtration area ranging from 800 to 16,000 m² is designed for an output more than 1 million m₃/h of with respect to cleaned gas. The new bag filter permits dry collection of sulfur oxides from waste gases at TPP operating on high-sulfur coals. The design of the filter makes it possible to replace filter elements without taking the entire unit out of service. __________ Translated from élektricheskie Stantsii, No. 3, March 2007, pp. 43–46.     

Look-ahead heuristics for the dynamic traveling purchaser problem

Given a set of products each with positive discrete demand, and a set of markets selling products at given prices, the traveling purchaser problem (TPP) looks for a tour visiting a subset of markets such that products demand is satisfied at minimum purchasing and traveling costs. In this paper we analyze a dynamic variant of the problem, where quantities may decrease as time goes on. Complete information is assumed on current state of the world, i.e. decision maker knows quantities available for each product in each market at present time and is informed about any consumption event when it occurs. Nevertheless, planner does not have any information on future events. Two groups of heuristics are described and compared. The first group consists of simplified approaches deciding which market to visit next on the basis of some greedy criteria considering only one of the two objective costs. The second one includes heuristics based on a look-ahead approach taking into account both traveling and purchasing costs and inserting some future prediction. Heuristics behavior has been tested on a large set of randomly generated instances under different levels of dynamism.     

Comparisons of α-amylase inhibitors from seeds of common bean mutants extracted through three phase partitioning

This study compared the inhibitory activity of α-amylase inhibitor (αAI) extracted from common bean (Phaseolus vulgaris L.) variety Hwachia, its nine mutants and two introduced varieties by using three-phase partitioning (TPP). A commercially prepared Phase 2 was also used to serve as a comparative reference. The optimal purification parameters for TPP were 30% saturation ammonium sulphate and pH 5.25. Considerable variations were detected in αAI content, total inhibitory activity and specific inhibitory activity of αAI purified from different common beans. Mutant SA-05 had the αAI inhibitory activity of 6267 units g⁻¹ dry seed weight, which was higher than Hwachia (5062 units g⁻¹ dry seed weight) and Phase 2 (3200 units g⁻¹ dry weight). Moreover, it had an extremely lower IC₅₀ (0.40 μg) than Phase 2 (10.22 μg). Thus, the mutant SA-05 may be used as raw material in commercial preparation of αAI extracts for controlling appetite and energy intake.     

采用形状记忆合金的瞬时隔热组合面料的研究

设计了由玄武岩织物外层、形状记忆合金弹簧形成的空气隔热层和芳砜纶面料内层构成的瞬时隔热组合面料,测试、比较并分析其TPP值和防火隔热性能,结果表明,该瞬时隔热组合面料的综合热防护性能远高于GA 10—2002《消防员灭火防护服》标准;用450℃的高温火焰喷射在组合面料上,20 s内冷面温度不超过50℃,可以隔开400℃以上的高温,空气层隔热效果明显。     

磷酸三苯酯/热塑性酚醛树脂在PC中协效阻燃作用的研究

采用磷酸三苯酯(TPP)和热塑性酚醛树脂(PF-T)复配阻燃聚碳酸酯(PC),探讨了TPP/PF-T不同配比以及阻燃剂添加总量变化对整个体系的阻燃性能及力学性能的影响。结果表明,当PC/TPP/PF-T质量比为80/10/10时,体系的氧指数达到46%,阻燃级别达到UL94V-0级;TPP/PF-T的协效作用机理为热解过程中PF-T与TPP发生酯交换反应而形成稳定的网状结构,抑制了TPP的挥发,提高了体系的热稳定性及阻燃性能。     

N,N,N-trimethyl chitosan nanoparticles as a vitamin carrier system

There is considerable interest in incorporating stabilized vitamins into biopolymeric nanoparticles, especially in the development of carriers and active systems for pharmaceutical and food applications. Amongst biopolymer, chitosan is highly desirable owing to its good biocompatibility, biodegradability and ability to be chemically modified. In this paper, nanoparticles from three kinds of water-soluble derivative chitosan (N,N,N-trimethyl chitosan, TMC) have successfully been synthesized by ionic gelation with tripolyphosphate (TPP) anions. Combinations of concentrations of TMC and TPP have resulted in nanoparticles with varying sizes for which the capability for loading with vitamins was investigated. Zeta potential measurement and particle size analysis demonstrated that the size of the nanoparticles was optimized (196 ± 8 nm) when the lowest TMC and TPP amounts were used, i.e., 0.86 mg mL⁻¹ and 0.114 mg mL⁻¹ respectively. As the TMC and/or the TPP concentrations increase, the resulting size of the nanoparticles increases considerably. Three different vitamins (B9, B12 and C) were tested as additives and the final system characterized in relation to size, morphology, spectroscopic and zeta potential properties. In general, the incorporation of vitamins increased all the TMC–TPP original nanoparticle sizes, reaching a maximum diameter of 534 ± 20 nm when loaded with vitamin C. The presence of vitamins also decreases the zeta potential, with one exception observed when using vitamin C. The preliminary results of this study suggested that all TMC/TPP nanoparticles can be successfully used as a stable medium to incorporate and transport vitamins, with potential applications in foodstuffs.     

Means of improving the economy of water-preparation units at TPP

Developments directed toward refinement of heating systems and thermal deaeration of feed and make-up water using regenerative taps of extraction turbines are presented. The Ul’yanovsk No. 1 TPP is used as an example to demonstrate the feasibility of one of the proposed solutions at a specific thermoelectric power plant. __________ Translated from élektricheskie Stantsii, No. 7, July, 2007, pp. 32–36.     

水溶性配体三-(间磺酸钠基三苯基)膦的合成工艺研究

以硫酸为溶剂，新蒸三氧化硫为磺化剂，研究了三氧化硫浓度对由三苯基膦(TPP)合成三—(间磺酸钠基三苯基)膦(TPPTS)反应的影响；采用IR光谱技术确定磺化反应终点，利用质子保护原理改进了稀释方法，详细分析了后处理过程中TPPTS的损失。其最佳反应条件是：m(SO3)：m(TPP SO3 H2SO4)=1:2，n(SO3)：n(TPP)=12：1，m(H2SO4)：，m(TPP)=3：1，反应温度22℃，反应时间40h。按此工艺合成的TPPTS含两个结晶水，纯度高达95％，收率大于85％。