Effect of ultrasonic treatment on the stability and release of selenium-containing peptide TSeMMM-encapsulated nanoparticles in vitro and in vivo

Rice selenium-containing peptide TSeMMM (T) with immunomodulatory functions was isolated from selenium-enriched rice protein hydrolysates. However, its biological activity is difficult to be protected in complex digestive environments. In this study, T was encapsulated within zein and gum arabian (GA) through ultrasound treatment to improve its bioactivity and bioavailability. The zein@T/GA nanoparticles were formed using ultrasonic treatment at 360 W for 5 min with a 59.9% T-encapsulation efficiency. In vitro digestion showed that the cumulative release rate of zein@T/GA nanoparticles reached a maximum of 80.69% after 6 h. In addition, short-term animal studies revealed that the nanoparticles had an effect on the levels of tissue glutathione and improved peptides’ oral bioavailability. Conclusively, these findings suggest that the ultrasonicated polysaccharide/protein system is suitable for encapsulating active small molecular peptides. Furthermore, it provides a novel foundation for studying the bioavailability of active substances in functional foods.     

Damping performance of Eucommia ulmoides gum

Eucommia ulmoides gum(EU gum),known as gutta percha in Southeast Asia,is a natural polymer with double characteristics of rubber and plastic.In present paper,tanδ-T curve and hysteresis loss(HL) were chosen to characterize its damping property.The results indicated that its tanδvalue would increase with rising of temperature when T>0℃and form another damping peak at 40-80℃besides T_g peak.This phenomenon resulted from meltage of crystals of EU gum could increase its damping property at ambient-high temperature.Its tanδvalue even exceeded those of conventional damping rubbers,such as nitrile-butadiene rubber(NBR) and chlorinated isobutene-isoprene rubber(CIIR).     

Preparation and characterization of oxidized sesbania gum and evaluation of its warp sizing performance for fine cotton yarns

Sesbania gum (SG) was oxidized by sodium hypochlorite. Resultant oxidized sesbania gum (OSG) was characterized by means of Fourier transformation infrared spectrometry, scanning electron microscopy, and high resolution transmission electron microscopy. The thermal stability of OSG was analyzed by means of thermal analysis and the apparent viscosity of its slurry was also measured by rotary viscometer. Moreover, the effect of OSG slurry as a warp sizing agent on the physico-mechanical properties of fine cotton yarns was investigated. It was found that fine cotton yarns sized with OSG had increased tensile strength and decreased elongation at break than the untreated ones. Besides, the fine cotton yarns treated with the OSG slurry had obviously decreased hairiness index and slightly increased abrasion resistance, and OSG slurry had good adhesion. In one word, as-synthesized OSG slurry may find promising application as a novel high-performance warp sizing agent for fine cotton yarns.     

微波消解-原子吸收光谱法测定瓜尔豆胶中的痕量铅

建立了微波消解-石墨炉原子吸收法测定瓜尔豆胶中铅的方法。探讨了样品的称样量及前处理条件、基体改进剂的选择以及仪器工作条件的优化。铅的线性范围为0～40.0μg/L,相关系数r=0.9996,方法的检出限为0.63μg/L,测定结果的相对标准偏差为1.32%～2.16%(n=6),加标回收率为90.3%～99.4%。该法准确、简单、灵敏度高,重现性好。     

浅谈柴油低烧一号技术在春、夏季行车中的使用

使用柴油低烧一号技术是目前铁路降低机车运行成本的重要途径之一。文章通过一系列的实验结果，证明了可以在春、夏季尝试使用 5^#柴油来大幅度降低内燃机车全年的运行成本。     

植筋在工程加固中的应用

植筋锚固技术是在工程加固中利用工程结构胶的粘结力,将钢筋生根种植在混凝土结构中,从而达到锚固作用.结合工程实例,详细说明了植筋的技术,证明了它的应用价值.     

金属交联羧甲基羟丙基瓜胶的红外光谱研究

本文研究了金属离子Ｆｅ＾３＋，Ｃｒ＾３＋，Ｔｉ＾４＋交联羧甲基羟丙基瓜胶的红外光谱及其冻胶的热失重行为，结果表明，在羧甲基羟丙基瓜胶冻胶中，参与配位的基团主要是羧甲基，主链上的邻位顺式羟基及羟丙基提供的活性部位，提出了金属离子与瓜胶交联的强弱顺序及其交联配位模式。     

Influence of temperature on the slip velocity of semidilute xanthan gum solutions

We obtain experimental evidence of the influence of temperature in the range 12-32°C on the slip phenomena of two different 0.3% xanthan solutions in a glass capillary rheometer. Enhancement of the slip velocity was observed for both samples around the corresponding thermally induced order-disorder transition temperature. Intrinsic viscosity measurements were performed to find the conformation change of both samples. Concentrations of 0.15% and 0.2% were analyzed for one sample, showing absence of slip at 0.15%.Slip velocity measurements were determined with the traditional Mooney method for a L/D ratio of the capillaries (640) enough to neglect entry head losses. Comparisons were done with the method developed by Piau et al. (1990) and with the one developed by Hatzikiriakos and Dealy (1992). The resulting behavior of the slip velocity with the capillary diameters, calculated with the method of Hatzikiriakos and Dealy, was contrary to the behavior experimentally found by other authors. The observed differences in the slip velocity, measured with the other two methods, were proportional and nearly independent of temperature and diameter of the capillaries.     

On rod-like polymers

Recent work on suspensions of rigid rod particles and molecules has prompted a search for some water soluble rigid-rod polymers and for a quick test of rod likeness.The existence of a liquid crystal phase is a good indication of the rod likeness of a polymer. A convenient, fast test for a liquid crystal phase involves drying of a small dilute sample of the polymer solution which is sandwiched between a glass slide and coverslip. The resulting sample is then examined by polarised light microscopy.The chemical structure of gums has lead to an examination of several samples of plant gums. A cheap, safe gum derived from seaweed (-carrageenan) was found to be rod-like in aqueous solution; -carrageenan exhibits a liquid crystal phase at a concentration of 12.5 g/100 ml. A liquid crystal phase is not observed in gums with linear backbones which have even short branches, leading to the conclusion that these can not be regarded as being rod-like in solution.     

Structure of gum arabic in aqueous solution

Gum arabic, a natural polysaccharide derived from exudates of Acacia senegal and Acacia seyal trees, is a commonly used food hydrocolloid. The complex chemical structure of the gum has been widely studied revealing a multifraction material consisting mainly of a highly branched polysaccharide and a protein–polysaccharide complex (GAGP) as a minor component. This work investigates its mesoscopic structure in aqueous solution by small‐angle X‐ray and neutron scattering combined with cryotransmission electrons microscopy. Scattering measurements reveal an intricate shape composed of many spheroidal aggregates assigned to the polysaccharide with a small amount of larger coils. A scattering peak is observed at moderate to high concentrations, the spacing of which exhibits a c^?1/3 power law relation to polymer concentration (c). Upon addition of salt, this peak disappears, indicating its electrostatic nature. The large coils contribute a q^?2 power law at the low scattering vector (q) range. However, at low concentration in which the interaggregate peak is not observed, a q^?1 power law at the low q range indicates the possible existence of a fraction with a locally extended conformation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3265–3271, 2006