Antidiabetic potential of Phyllanthus reticulatus in alloxan-induced diabetic mice

The plant Phyllanthus reticulatus is claimed to have antidiabetic activity in tribal area. To validate the tribal claim, the petroleum ether and ethanolic extracts of leaves of the P. reticulatus were orally tested at 500 and 1000 mg/kg for hypoglycemic effect in alloxan induces diabetic mice. It shows antidiabetic activity at the dose of 1000 mg/kg. The phytochemical screening of the residues revealed the presence of terpenoids glycosides, protein, carbohydrates and absence of alkaloids and steroids.     

Sorption behavior of volatile phenols at the oak wood/wine interface in a model system

The sorption in a model system of aroma compounds of enological interest (mixture of the eight derivatives from guaiacol, 4-ethylphenol, and whiskylactone) onto wood was investigated to assess the influence of wood on the concentration of these volatiles during the aging of wine. To evaluate the influence of the solubility of aroma compounds in sorption phenomena, this parameter was determined for each volatile compound in model wine at 10 and 25 degrees C. The solubility is significantly higher in the model wine than in water and remains constant in the range of temperatures studied, except for guaiacol and vanillin. Kinetic and equilibrium sorptions were investigated. Sorption kinetics showed that the sorption equilibrium for all aroma compounds was reached after 6-7 days. From the study of the individual sorption isotherms, two distinct kinds of sorption behavior were observed depending on the presence or not of an ethylenic para substituent conjugated to the phenyl ring. K(ww) partition coefficients between the wood and the model wine were determined, which exhibited an unusual positive variation with temperature.     

Different sorption behaviors for wine polyphenols in contact with oak wood

The evolution of polyphenols of enological interest- monomeric anthocyanins, (+)-catechin, (-)-epicatechin, gallic acid, and trans-resveratrol-in the presence of oak wood was investigated in aging-model conditions. Disappearance kinetics showed that, except for gallic acid, all of the wine polyphenols tend to disappear from the model wine in presence of oak wood, to reach an equilibrium after 20 days of contact. At equilibrium, the higher disappearance rates were obtained for monomeric anthocyanins and trans-resveratrol with values of 20 and 50%, respectively. For monomeric anthocyanins, the rate of disappearance seemed to be independent of their nature. In order to evaluate the contribution of sorption to oak wood in the disappearance phenomena, sorption kinetics were determined for trans-resveratrol and malvidin-3-glucoside through the extraction and the quantification of the fraction sorbed to wood. These curves showed that the wood intake of trans-resveratrol and malvidin-3-glucoside followed a two-step behavior, with a higher rate during the first 2 days, likely due to a surface sorption mechanism, and then a slower rate to reach the equilibrium, which could be related to a diffusion mechanism. The comparison of disappeared and sorbed amounts at equilibrium showed that a minor part of the disappeared monomeric anthocyanins were sorbed by wood. In contrast, half of the concentration decrease of trans-resveratrol in wine finds its origin in a sorption mechanism by oak wood. Results in real wine show similar sorption kinetics.     

Cross-linking and rheological changes of whey proteins treated with microbial transglutaminase

Modification of the functionality of whey proteins using microbial transglutaminase (TGase) has been the subject of recent studies. However, changes in rheological properties of whey proteins as affected by extensive cross-linking with TGase are not well studied. The factors affecting cross-linking of whey protein isolate (WPI) using both soluble and immobilized TGase were examined, and the rheological properties of the modified proteins were characterized. The enzyme was immobilized on aminopropyl glass beads (CPG-3000) by selective adsorption of the biotinylated enzyme on avidin that had been previously immobilized. WPI (4 and 8% w/w) in deionized water, pH 7.5, containing 10 mM dithiothreitol was cross-linked using enzyme/substrate ratios of 0.12-10 units of activity/g WPI. The reaction was carried out in a jacketed bioreactor for 8 h at 40 degrees C with continuous circulation. The gel point temperature of WPI solutions treated with 0.12 unit of immobilized TGase/g was slightly decreased, but the gel strength was unaffected. However, increasing the enzyme/substrate ratio resulted in extensive cross-linking of WPI that was manifested by increases in apparent viscosity and changes in the gelation properties. For example, using 10 units of soluble TGase/g resulted in extensive cross-linking of alpha-lactalbumin and beta-lactoglobulin in WPI, as evidenced by SDS-PAGE and Western blotting results. Interestingly, the gelling point of WPI solutions increased from 68 to 94 degrees C after a 4-h reaction, and the gel strength was drastically decreased (lower storage modulus, G'). Thus, extensive intra- and interchain cross-linking probably caused formation of polymers that were too large for effective network development. These results suggest that a process could be developed to produce heat-stable whey proteins for various food applications.     

VD在骨骼外系统中的作用及其研究进展

以往普遍认为VD的主要功能是调节Ca离子来促进骨骼的生长和预防佝偻病,但最近几年的研究发现,VD不仅在骨骼疾病中起到重要作用,还与多种骨骼外疾病密切相关,包括一些心血管疾病、代谢紊乱有关的疾病、恶性肿瘤、过敏性疾病、自身免疫性疾病、生殖方面影响等。目前对VD生物学功能的研究比较全面和深入,但大部分是针对人体和小鼠的基础研究,对诸如牛、猪、犬、猫等不同动物VD的骨骼外系统生物学功能的研究较少。在查阅相关文献的基础上,通过对VD在血压、免疫调节、内分泌、子宫内膜和骨骼肌方面的生物学功能和研究进展进行总结,为不同动物VD在骨骼外系统生物学功能的研究提供一定参考。     

营养土理化性质对香蕉组培袋苗生长影响的初步研究

初步研究了营养土理化条件及肥料３要素的比例对香蕉组培袋苗（以下简称袋苗）生长的影响。试验结果表明：袋苗需要较为湿润的土壤条件，最适宜的土壤含水量为其田间持水量的６０％～８０％；土壤质地对袋苗生长有极显著的影响，袋苗生长最适宜的土壤质地为中壤至重壤；最宜袋苗生长的土壤ｐＨ为６．５左右，袋苗在ｐＨ６．５～７．０范围内生长良好，ｐＨ〈５．５或ｐＨ〉７．５时，其生长均受抑制；Ｎ、Ｐ素对袋苗生长的影响极显著     

"Debye-Scherrer Ellipses" from 3D fullerene polymers: An anisotropic pressure memory signature

High-pressure studies on fullerenes have previously shown the existence of one- and two-dimensional (2D) polymerized C60 structures. Synchrotron radiation measurements, performed on C60 samples quenched from 13 gigapascals and 820 kelvin, yield unambiguous proof for the existence of a three-dimensional (3D) polymerized C60 derivative. Moreover, unusual ellipsoidal Debye-Scherrer diffraction patterns are observed, which shows that the giant anisotropic deformation induced by the nonhydrostatic compression is retained in the quenched samples. The multiple bonding possibilities of the highly symmetrical C60 allow the retention (down to ambient pressure) of the deformation, a phenomenon reported previously only under high pressure.     

Discovery of a young planetary-mass binary

We have identified a companion to the young planetary-mass brown dwarf Oph 162225-240515. This pair forms a resolved binary consisting of two objects with masses comparable to those of extrasolar giant planets. Several lines of evidence confirm the coevality and youth of the two objects, suggesting that they form a physical binary. Models yield masses of approximately 14 and approximately 7 times the mass of Jupiter for the primary and the secondary object, respectively, at an age of approximately 1 million years. A wide ( approximately 240-astronomical unit) binary in the ultra-low-mass regime poses a challenge to some popular models of brown dwarf formation.     

山羊卵母细胞的体外成熟和受精

在有颗粒细胞，促卵泡素，促黄体素及１７β雌二醇存在的情况下，裹着卵泡卵丘细胞的山羊卵母细胞的体外成熟。从直径２－６ｍｍ的卵泡中获得的卵母细胞，有８６％成熟分裂；而直径为１－２ｍｍ的留言簿包，只有２４％的卵母细胞达到中期Ⅱ。卵泡卵丘母细胞复合体，培养前在２０℃下处理，结果有１１．５％的卵母细胞出现不正常的减数分裂的纺缍体。