Monoterpenes and Epicuticular Waxes Help Female Autumn Gum Moth Differentiate Between Waxy and Glossy Eucalyptus and Leaves of Different Ages

The autumn gum moth, Mnesampela privata, is a native Australian species whose preferred host, Eucalyptus globulus (Myrtaceae), is an aromatic evergreen tree that has long-lived waxy leaves during the juvenile phase of growth. We compared the behavioral and antennal responses of female moths to whole leaves (new and old) and samples of foliar chemicals (from new and old leaves) from a typical E. globulus subsp. pseudoglobulus with responses to a glossy, half-sibling E. g. subsp. pseudoglobulus putative hybrid (the result of natural cross-pollination). We also studied larval survival and development on leaves from the same trees. In laboratory binary-choice assays, female M. privata laid more eggs on waxy leaves than on glossy leaves thereby confirming the nonpreference for the glossy tree that was observed in the field. Analyses of the monoterpenes and waxes of both trees revealed that they had comparable suites of monoterpenes and total oil contents but different suites of epicuticular waxes. Headspace extracts differed in the intensity of component monoterpenes. Gas chromatographic analyses with electroantennographic detection showed different patterns of monoterpene detection. Leaves of the glossy tree had a less diverse array of epicuticular waxes than those of the waxy tree. Electroantennographic screening of responses to wax extracts from leaves (new and old) from either tree revealed positive dose-dependent responses of female antennae to waxes from new leaves only. Binary-choice assays also revealed a strong preference by ovipositing females for new, compared to old, leaves whether they were from the waxy or the glossy tree. However, new leaves from either tree could be manipulated (by physical abrasion of epicuticular waxes) so that females would lay almost no eggs on them. Larval survival did not differ between groups reared on leaves from both trees (new and old). Over 70% of all larvae survived to pupation. However, larvae reared on leaves from the glossy tree took longer to pupate than those reared on leaves from the waxy tree. Also, larvae reared on new leaves from either tree did not perform as well as those reared on old leaves. Monoterpene and wax cues are suggested as helping female M. privata locate preferred hosts in native forests.     

利用废聚乙烯薄膜制造石蜡的研究

本文主要讨论了用废聚乙烯薄膜制石蜡的可行性.采用高温、低压的反应条件,加入自制的催化剂;可制得石蜡,其熔点在54～57(℃)产率达80％以上.该研究给塑料的利用,净化环境提供了可靠的依据.     

A Predictive Classification Model for the Management of Virgin Olive Oil Filtration at Industrial Scale

Precoat-bodyfeed filtration of virgin olive oil was investigated on an industrial filter-press plant. Several chemical parameters of the unfiltered oil were measured and the relationship with filtration performances was investigated by Principal Component Analysis. Further, Linear Discriminant Analysis was applied to develop a predictive model for oil filterability. Principal Component Analysis allowed the construction of latent variables which were used to separate oil groups and to select variables for Linear Discriminant Analysis. The developed linear model gave an overall correct recognition of about 88%, good enough for a convenient filterability prediction of oil at industrial scale.     

Polydisperse Powder Mixtures: Effect of Particle Size and Shape on Mixture Stability

ABSTRACT

The effect of the shape and size of the components on the stability of mixtures was evaluated in binary mixtures of drug and carrier. Aspirin was used as model drug; spray-dried lactose and microcrystalline cellulose were used as carriers. The coefficient of variation (CV) of the drug in the mixture at various time intervals during mixing was used as a measure of homogeneity. The stability of mixtures was assessed under conditions that were conducive to segregation—in this case, prolonged mixing. The pattern of change in CV with time was analyzed in terms of convective, shear, and diffusive mixing stages. The variation resulting from a change in the shape of the carriers was smaller than that resulting from size differences. The segregation rate constant, calculated on the assumption of a first-order mixing process, was found to be larger in mixtures having components of different shape than in mixtures having components of similar shape. In mixtures of micronized drug and carrier, the pattern of change in the CV of drug with mixing time was attributed to the distribution of agglomerates of micronized drug during convective mixing, followed by shearing of agglomerates and, finally, the distribution of the primary particles during diffusive mixing. Mixtures of non-cohesive powders of similar size and shape behaved like random mixtures of non-interacting components.     

微细化玉米淀粉粒度效应及其流变学行为研究

采用现代粉体机械可制备微细化玉米淀粉。随着淀粉粒度减小,其支链淀粉和直链淀粉糊的特性黏度降低,分子量下降。布拉班德黏度分析表明,微细化玉米淀粉糊化起始温度下降,热糊稳定性增强;在冷却阶段,随着粒度降低,微细化玉米淀粉的凝沉性较原玉米淀粉增强,冷糊稳定性较原玉米淀粉减弱。微细化玉米淀粉糊为非牛顿假塑性流体,其流动性随粒度降低而增加,并显示出一定的粒度效应。     

超微淀粉在LDPE中分散性及其共混体系性能研究

研究了平均粒径2．91μm的超微淀粉偶联改性后在LDPE中的分散，及其共混物熔体流变性和超微淀粉／LDPE膜的力学性能。结果表明，超微淀粉的偶联量可达1％。超微淀粉／LDPE熔体为非牛顿假塑性流体，随着剪切速率的提高，熔体表观粘度降低；随着淀粉粒径的减小，熔体流动性得到改善。超微淀粉／LDPE膜中淀粉质量分数可达50％，拉伸强度达15．6MPa，断裂伸长率为469％。SEM显示超微淀粉在LDPE中分散性良好。     

Progesterone: Review of safety for clinical studies.

Progesterone is a steroid hormone that is important for reproductive function. Progesterone is used in a number of clinical applications and has been investigated as a possible novel approach for treatment of stimulant drug abuse. Extensive clinical studies have been conducted to examine the subjective and physiological effects of exogenous progesterone administration and to evaluate its side effects. This review summarizes the safety and side effects of acute and chronic administration of 3 progesterone formulations (synthetic, natural, and micronized natural), several routes of administration (oral, intramuscular, intravenous, intravaginal, intranasal, transdermal, and rectal), and dosing regimens. Synthetic progestins marketed as Provera, PremPro, and Cycrin are widely used but may produce a number of significant side effects, such as fatigue, fluid retention, lipid level alterations, dysphoria, hypercoagulant states, and increased androgenicity. Natural progesterones are reported to have milder adverse effects, depending on the route of administration. Micronized natural progesterone is available for oral administration, has better bioavailability and fewer side effects than natural progesterone, and is convenient to administer. Therefore, micronized natural progesterone appears to be a safe and effective alternative to synthetic and natural progesterone formulations for variety of clinical and research applications. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hydrocracking of Fischer‐Tropsch waxes: Kinetic modeling via LHHW approach

A lumped kinetic model to describe the hydrocracking of complex mixtures of paraffins, such as Fischer‐Tropsch waxes, has been developed. A Langmuir‐Hinshelwood‐Hougen‐Watson approach has been followed, accounting for physisorption by means of the Langmuir isotherm. Finally, a complete form of the rate expression is used, thus introducing the equilibrium constants for dehydrogenation and protonation elementary steps. To minimize the number of model parameters, the kinetic and thermodynamic constants are defined as functions of the chain length. Vapor–liquid equilibrium is calculated along the reactor, and the hydrocarbons concentrations are described by means of fugacity. The model provides quite a good fitting of experimental results and is able to predict the effects of the operating conditions (temperature, pressure, H₂/wax ratio, and WHSV). Outstandingly, the estimated values and trends of the kinetic and thermodynamic constants (activation energies, Langmuir adsorption constants, etc.) are in line with their physical meaning. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

微细化淀粉颗粒形貌及显微结构分析

采用真空球磨设备,以食用级马铃薯淀粉、木薯淀粉及玉米淀粉为原料,制备不同粒度的微细化淀粉,并对淀粉粒度变化、形貌及聚集态结构等进行表征。扫描电镜形貌分析表明,淀粉颗粒在球磨处理过程中,其形貌特征发生了明显的变化,淀粉颗粒破碎首先发生在颗粒的缺陷处、裂纹处、结晶区处等应力相对集中的区域,当球磨处理时间继续增加时,会呈现一种细化与团聚并存的动态平衡;研究中还发现,淀粉在微细化处理中,并不单是淀粉表面薄层逐渐剥落的过程,大多淀粉颗粒呈现出大块层破碎、淀粉核心崩解等现象。     

Separation of Paraffin Wax Using Solvent Fractionation

In order to separate and characterize some grades of paraffin waxes from El-Ameria crude waxes (slack waxes), a one-stage fractional crystallization technique has been done to separate the paraffin waxes with different characteristics by using different solvents and solvent mixtures at ambient temperature of 20°C and fixed dilution and washing solvent ratios (S/F) of 4:1 and 2:1 by weight, respectively. The fractionating solvents used are n-hexane, methyl isobutyl ketone (MIBK), dioxane, ethyl acetate, and butyl acetate as a single solvent and a mixture of methyl ethyl ketone (MEK) containing benzene (B) and toluene (T) as a mixed solvent. The resulting data revealed that dioxane and n-hexane solvents are not suitable for fractional crystallization of slack waxes, and the most suitable solvents for separating paraffin waxes with the standard specifications are ethyl and butyl acetates, MIBK, and the mixture of MEK, B, and T (60:20:20 by weight, respectively).