Hypolipidemic effect of soluble fiber isolated from seeds of Cassia tora Linn. in rats fed a high-cholesterol diet

Soluble fibers isolated from the seeds of Cassia tora Linn. (SFC) have attracted considerable attention in recent years due to their phenomenal rheological behavior. In this study were investigated the effects of SFC on lipid metabolism. Male Sprague-Dawley rats were fed one of three experimental diets, a normal diet, a high-cholesterol diet, or a high-cholesterol diet with 5% SFC, for 5 weeks. The serum concentration of total cholesterol in rats fed SFC was 27% lower (p < 0.05) compared to that of the control group, but the serum high-density lipoprotein cholesterol level was increased in the SFC group. Liver total cholesterol and triglyceride levels were reduced significantly (p < 0.05) in rats fed the SFC diet. In addition, fecal bile acid and lipid excretion was significantly increased by SFC consumption. These results indicate that SFC enhances fecal lipid excretion and may cause a reduction in serum and hepatic lipid concentrations in rats.     

Nonenzymatic antioxidative and antiglycative effects of oleanolic acid and ursolic acid

Oleanolic acid and ursolic acid are two triterpenes presented in several herbs. This study analyzed the content of oleanolic acid and ursolic acid in eight locally available fresh herbs, also examined several nonenzymatic antioxidant activities of these two triterpenes, and used a liposome system to evaluate the influence of temperature and pH upon the antioxidant property of these two triterpenes. The impact of these two triterpenes on the production of nonenzymatic glycative products, pentosidine and carboxymethyllysine (CML), was also evaluated. alpha-Tocopherol was used for comparison. Results showed that the content of oleanolic acid and ursolic acid in glossy privet fruit and hawthorn fruit varied from season to season and was in the range of 200-650 microg/g of fresh weight. Both oleanolic acid and ursolic acid possessed greater antioxidant activity against 2,2'-azobis-(2-amidinopropane) dihydrochloride and less antioxidant activity against 2,2'-azobis(2,4-dimethylvaleronitrile) when compared with alpha-tocopherol at equal concentration (P <0.05). At 75 and 100 degrees C, oleanolic acid exhibited greater antioxidant activity than alpha-tocopherol and ursolic acid (P <0.05). At pH 2 and pH 4, oleanolic acid and ursolic acid showed greater antioxidant activity than alpha-tocopherol (P <0.05). These two triterpenes also exhibited a dose-dependent effect in superoxide anion scavenging activity, chelating effect, xanthine oxidase inhibition activity, and reducing power (P <0.05). Oleanolic acid significantly and dose-dependently inhibited pentosidine and CML formation (P <0.05). Ursolic acid also significantly suppressed CML formation (P <0.05). These data support that these two triterpenes possessed nonenzymatic antioxidative and antiglycative properties.     

N-羟乙酰神经氨酸研究进展

N-羟乙酰神经氨酸(Neu5Gc)是人类和鸡某些癌症疾病中的一种特异性标志物,主要作为Hanganutziu-Deicher抗原存在.人和鸡的正常细胞中不含有Neu5Gc,它在细胞间识别、黏附、炎症反应和肿瘤细胞转移中起重要作用.论文从Neu5Gc的生物合成、分布、细胞信号转导、免疫学特性和病理学意义等诸多方面多Neu5Gc进行综述,对Neu5Gc的全面认识将为预防肝癌、结肠癌等肿瘤疾病和一些病毒性传染病开辟一条新的诊断和防治途径.     

Comparative study on the aflatoxin B1 degradation ability of rumen fluid from Holstein steers and Korean native goats

The aflatoxin B1 degrading abilities of two different ruminants were compared in this study. One set of experiments evaluated the aflatoxin B1 degradation ability of different rumen fluid donors (steers vs. goats) as well as the rumen fluid filtration method (cheese cloth filtered vs. 0.45 µm Millipore) in a 2 × 2 factorial arrangement. Additional studies examined aflatoxin B1 degradation by collecting rumen fluid at different times (0, 3, 6, 9 and 12 h) after feeding. Cannulated Holstein steers (740 ± 10 kg bw) and Korean native goats (26 ± 3 kg bw) were fed a 60% timothy and 40% commercial diet with free access to water. Rumen fluid from Korean native goats demonstrated higher (p < 0.01) aflatoxin B1 degradability than Holstein steers. However, filtration method had no significant influence on degradability. In addition, aflatoxin degradation did not depend upon rumen fluid collection time after feeding, as no significant differences were observed. Finally, a comparison of two types of diet high in roughage found aflatoxin degradability in goats was higher with timothy hay opposed to rice straw, although individual variation existed. Thus, our findings showed the aflatoxin degradability is comparatively higher in goats compared to steers.     

粒子群算法在农业水文学中的应用进展

优化问题一直是农业水文学研究的重要问题之一,而粒子群算法作为新型智能算法具有很好的寻优能力.介绍了粒子群算法的流程和步骤,以及各种改进后的粒子群算法,分析了粒子群算法在农业水资源优化配置、农田节水灌溉措施、农作物种植优化等农业水文学几个方面的应用现状.结果表明,粒子群算法在农业水文学中的应用范围有限;现有应用研究重视经济效益最大化,忽视社会生态效益;研究呈现碎片化的现象,未形成完整的学科理论体系;改进后的粒子群算法具有更好的寻优能力.指出粒子群算法与其他优化算法和技术结合将会为该算法在农业水文学中的发展开辟新的方向和道路,为农业水文学中科学问题的解决得出更好的优化结果.     

Synthesis and measurement of ultrafast waveforms from five discrete optical harmonics

Achieving the control of light fields in a manner similar in sophistication to the control of electromagnetic fields in the microwave and radiofrequency regimes has been a major challenge in optical physics research. We manipulated the phase and amplitude of five discrete harmonics spanning the blue to mid-infrared frequencies to produce instantaneous optical fields in the shape of square, sawtooth, and subcycle sine and cosine pulses at a repetition rate of 125 terahertz. Furthermore, we developed an all-optical shaper-assisted linear cross-correlation technique to retrieve these fields and thereby verified their shapes and confirmed the critical role of carrier-envelope phase in Fourier synthesis of optical waveforms.     

Spatial distributions of metal(loid)s and their transport in agricultural soils around abandoned metal mine sites in South Korea

Journal of Soils and Sediments - To develop efficient strategies and methods to remediate soils contaminated by metal(loid)s, it is vital to monitor the metal(loid)s in the soil by conducting field...