植物有效成分提取方法的研究

针对目前国内外研究植物有效成分的常用提取、分离技术和方法,对比分析了各种常用的提取、分离技术和方法的适用性和局限性,通过多种提取方法的例举描述了现代植物有效成分的研究现状,并阐述了植物提取分离技术的发展前景。     

The role of enzymes in modern detergency

Enzymes have effectively assisted the development and improvement of modern household and industrial detergents. The major classes of detergent enzymes—proteases, lipases, amylases, and cellulases—each provide specific benefits for application in laundry and automatic dishwashing. Historically, proteases were first to be used extensively in laundry detergents. In addition to raising the level of cleaning, they have also provided environmental benefits by reducing energy consumption through shorter washing times, lower washing temperatures, and reduced water consumption. Today proteases are joined by lipases and amylases in improving detergent efficacy especially for household laundering at lower temperatures and, in industrial cleaning operations, at lower pH levels. Cellulases contribute to overall fabric care by rejuvenating or maintaining the new appearance of washed garments. Enzymes are produced by fermentation technologies that utilize renewable resources.     

Photocatalytic degradation of thiocarbamate herbicide active ingredients in water

It has been shown that a wide range of organic compounds in aqueous solutions is photocatalytically oxidized to carbon dioxide in the presence of titanium dioxide with near-UV radiation. The photocatalytic mineralization of thiocarbamate derivative pesticides (EPTC, butylate, molinate, vernolate and cycloate) in water by illuminated TiO₂ has been studied. The determination of the effects of various kinetic factors on the photocatalytic degradation and the determination of the nature of the principal intermediates form part of the focus of this study. The degradation rate of these thiocarbamates in a continuous recirculation mode approximates first-order kinetics. It was demonstrated that photocatalyzed degradation of thiocarbamate active ingredients does not occur instantaneously to form carbon dioxide, but through the formation of long-lived intermediate species. Photocatalytic intermediates detected during the degradation of thiocarbamates were identified by GC/MS techniques. Intermediates detected in the photocatalytic oxidation of thiocarbamates in water solutions are in excellent agreement with products identified from the atmospherically important reactions of OH radical with thiocarbamates. Particular attention will be paid to the carbon dioxide formed from the illuminated suspension in order to demonstrate not only apparent destruction but also complete mineralization. The degradation of a two-component mixture was carried out and compared to results obtained with single-component studies.     

Separation and quantitative determination of active ingredients in detergent formulations

During the past few years, the increasing complexity of detergent formulations has required the analytical detergent chemists to devise many new and complicated separation schemes. This paper describes a method which allows the separation and quantitative determination of linear alkylbenzene sulfonate (LAS), ethoxylated alcohol sulfate (AES), alcohol sulfate (AS), free nonionic and amine oxide in detergent formulations. A combination of ion exchange, chemical separations, and gas chromatography is used in the described method. In addition to quantitating the types of “active” material listed, the ethylene oxide content of the ethoxylated alcohol sulfate and the homolog distribution of the alcohol hydrophobe in both the ethoxylated alcohol sulfate and the alcohol sulfate are obtained. This separation scheme is applicable to either liquid or powdered detergent formulations.     

折纯计量代替实物计量在企业成本控制中的重要意义

<正>我国磷化工产业规模大,国内销售已处于供大于求的饱和状态,随着新的磷化工企业不断诞生和国家政策向保护磷资源的倾斜,磷化工产业竞争日益激烈。磷化工企业具有原材料成本占比大、生产连续、一次性投资高等特点,行业内各企业收益率低,向管理要效益,压缩生产成本已成为共同的追     

The design and synthesis of biologically active organophosphorus compounds--the role of a central research laboratory

The properties and benefits offered by incorporating phosphorus into molecules are varied and numerous as shown by the many divisional research programs within Ciba-Geigy in the early eighties. This paper describes how a Central Research Group developed new materials in organophosphorous chemistry and identified new leads for life science applications.     

美白活性原料的筛选及其特性研究

对绿茶、葡萄籽和巴西大樱桃等23种植物提取物对酪氨酸酶的抑制作用以及其抗氧化能力(清除羟基自由基和超氧阴离子自由基的能力)进行了研究.实验结果表明,20种样品均表现出不同程度的酪氨酸酶抑制作用和抗氧化能力,其中绿茶、巴西大樱桃和葡萄籽提取物表现出极强的酪氨酸酶活性抑制率,且抑制活性远高于熊果苷;同时这3种植物提取物也表现出显著的清除羟基自由基和超氧阴离子自由基的能力,具有应用于美白化妆品的潜力.     

Swellable hydrogel matrices for the release of the pendent chain-linked active ingredients over extended time periods

Zero-order release of the physically dispersed active ingredients from the glassy hydrogels has been explained in the past on the basis of the case II transport of the penetrant medium into the matrix. This communication reports the zero-order release of the pendent chain-linked p-nitrobenzoic acid from glassy as well as swollen hydrogel matrices. This has been explained on the basis of the time-dependent diffusivity of p-nitrobenzoic acid resulting from the structural changes in the matrix accompanying the release. p-Nitrobenzoic acid would be released from these systems at a constant rate for periods of up to 5 months. Implants of this type in which the drug molecule is linked to the polymer backbone through the pendent chain are potentially promising systems for drug delivery at a constant rate for extended time periods.     

Evidence for the unique function of docosahexaenoic acid during the evolution of the modern hominid brain

The African savanna ecosystem of the large mammals and primates was associated with a dramatic decline in relative brain capacity associated with little docosahexaenoic acid (DHA), which is required for brain structures and growth. The biochemistry implies that the expansion of the human brain required a plentiful source of preformed DHA. The richest source of DHA is the marine food chain, while the savanna environment offers very little of it. ConsequentlyHomo sapiens could not have evolved on the savannas. Recent fossil evidence indicates that the lacustrine and marine food chain was being extensively exploited at the time cerebral expansion took place and suggests the alternative that the transition from the archaic to modern humans took place at the land/water interface. Contemporary data on tropical lakeshore dwellers reaffirm the above view with nutritional support for the vascular system, the development of which would have been a prerequisite for cerebral expansion. Both arachidonic acid and DHA would have been freely available from such habitats providing the double stimulus of preformed acyl components for the developing blood vessels and brain. The n-3 docosapentaenoic acid precursor (n-3 DPA) was the major n-3-metabolite in the savanna mammals. Despite this abundance, neither it nor the corresponding n-6 DPA was used for the photoreceptor nor the synapse. A substantial difference between DHA and other fatty acids is required to explain this high specificity. Studies on fluidity and other mechanical features of cell membranes did not reveal a difference of such magnitude between even α-linolenic acid and DHA sufficient to explain the exclusive use of DHA. We suggest that the evolution of the large human brain depended on a rich source of DHA from the land/water interface. We review a number of proposals for the possible influence of DHA on physical properties of the brain that are essential for its function.     

浅谈中国传统装饰在现代陶瓷设计中的传承

几千年的工艺美术历史为我们留下了许多宝贵的遗产,中国传统装饰是我们设计灵魂的源泉,剪纸、蜡染、刺绣等民间艺术也完全可以为我们的现代陶瓷装饰设计增光添彩。中国的现代陶瓷装饰文化馆的形成和设计风格的追求,都必须根据当前中国人自己的生活需求和审美需求,以及中国特有的文化模式来进行,设计出具有东方神韵和民族特色的陶瓷产品。1、中国传统装饰概述中国数千年的浩瀚历史,传统装饰艺术就像一颗颗嵌在艺术史项链上的璀璨明珠,     

金银花活性成分提取及其抗氧化和抑菌功效研究

利用超声波预处理结合乙醇回流提取法从金银花中提取活性成分,通过响应面分析法设计实验,得到了较佳的提取工艺:超声波预处理30.9 min,乙醇的体积分数为73.7%,提取温度为68.5℃,每次提取2.1 h,提取2次,在此条件下绿原酸提取率达到88.39%。通过与阳性物质VC比较检验了提取物的功效,证明金银花提取物具有较好的体外抗氧化能力;通过对大肠杆菌、金黄色葡萄球菌、黑曲霉的抑制分析,证明金银花提取物具有良好的抑菌防腐能力。     

关于陶瓷艺术与现代产品设计的融合

近年来,在社会经济快速发展的同时,人们的生活水平越来越高,在基本物质生活需求得以满足以后,对产品的质量提出了更高要求,希望能够在追求物质满足的同时,实现精神层面的满足在这种情况下,现代产品设计需要更好的提升自身的设计理念,将更多的传统文化融入其中,实现现代产品艺术性的提升。在我国传统的艺术形式中,陶瓷艺术作为其中的重要组成,对人们的日常生活产生了直接的影响,而其中所包含的各种有益元素,为现代产品设计理念的创新提供了可靠保障。因此,在当前的现代产品设计中,应该实现与陶瓷艺术的融合,从不同的角度对陶瓷艺术与现代产品设计理念融合进行分析,采取有效的措施,发挥出陶瓷艺术在推动现代产品设计中的作用,满足人们的精神文化需求。     

从现代生活方式谈现代陶瓷艺术设计

现代社会意识和人们的审美心理发生了巨大的变化,对现代陶瓷艺术设计提出了严峻的要求。本文从现代生活方式角度出发,提出从陶瓷设计观念、造型、意蕴、装饰、材料及工艺技术等方面进行变革创新,以达到适应现代生活方式、审美趣味的目的。     

红景天活性成分的提取工艺及其美容功效研究

利用水提法从植物红景天的根中提取活性成分,通过四因素三水平正交试验得到了较佳的提取工艺:红景天根粉碎过60目筛、料液(红景天根和去离子水)质量比1:10、提取温度100℃、提取时间10 min.提取液中的活性成分红景天苷和总黄酮的含量分别用高效液相色谱法和三氯化铝比色法测定.通过与阳性物质对照比较检验了提取液的功效,证明红景天提取液具有体外抗氧化和抑制酪氨酸酶的能力,可以作为延缓衰老和美白化妆品添加剂.     

The role of kinetics in the design of plasma microreactors

Miniaturization of plasma reactors has the potential of low power operation. In general, the electric field strength in the gap between two electrodes increases proportionate to inverse of the gap width, so that it is possible to overcome the first ionization potential of the gas with a low voltage. However, plasmas are extinguished primarily by recombination at the walls. Wall collisions are enhanced by the greater surface area to volume ratio in microchannels, which also increases proportionate to the inverse of the gap width. If the plasma were well mixed, then the plasma creation in the bulk would be balanced by extinction at the wall, providing no particular advantage with regard to low voltage/low power operation. However, the plasma is transferred from the bulk to the wall by ambipolar diffusion. If the operation of the plasma microreactor is essentially transient or batch, whether or not the reaction kinetics are comparable to or faster than ambipolar diffusion determines if there is a regime of operation in which a low voltage plasma discharge can generate a high yield of product. In this paper, this question is investigated with regards to the ozone formation reaction and a particular design of a microchannel plasma reactor, with parameters so chosen to arguably achieve low voltage operation. The focus of this paper is the simulation of the kinetics of the plasma reactions leading to ozone formation, which shows a time to completion that is comparable (10^?2 s) or faster than the estimate of ambipolar diffusion time at these length scales. Preliminary results of a microchip reactor are consistent with this prediction.     

Optimization of extraction conditions for active ingredients of Suye Huanglian Decoction and its anti-influenza effect in vivo

ABSTRACT

Uniform design method (UD) was performed to define the levels of impact factors. The contents of anti-influenza active ingredients, extraction yield, and the influenza virus inhibition ratio were measured to evaluate the Suye Huanglian Decoction (SHD) aqueous extraction processes. The best optimal extraction process was optimized by genetic algorithm (GA). Further SHD extract was obtained under the optimal extraction process (add 28-fold water, extract for 108 min at 97°C for triple re-extraction). And the pneumonia mouse model established was used to investigate the anti-influenza effect of SHD. The results in vivo showed the optimized SHD exerted an excellent anti-influenza agent.     

浅谈现代陶瓷设计的多元化思维

在现代陶瓷设计当中，设计的主要因素主要是适应现代人的生活方式和时代审美旨准，因为现代人的工作和生活方式比较多元化，所以形成了现代陶瓷设计多向思维和定位。这就要求我们对其中的共性和个性的认知和把握，它在很大程度上决定设计的成功与否。针对当前的陶瓷市场上有部分的陶瓷产品在材质器型和花面上存在着比较雷同或不足的地方，开发和设计更多适应人们生活的陶瓷产品是陶瓷设计者应该进行反思考。     

Synergistic effect of silane modified nanocomposites for active corrosion protection

This work presents an effective anticorrosion behavior of a hydrophobic surface on stainless steel 304. The protective coating has been designed by dispersing nanocomposites (cloisite 15A, multiwalled carbon nanotubes and cerium chloride) which act as a corrosion inhibitor. The sol was prepared by using 3-glycidoxypropyltrimethoxysilane (GPTMS), octyltriethoxysilane (OTES) and zirconium (IV) butoxide as precursors. The corrosion resistance of coated stainless steel got improved when nanocomposites were homogeneously embedded in silica sol. The influence of nano-particles on the barrier coatings impedes corrosion. The coatings were analyzed by X-ray diffraction (XRD) to ensure the intercalation and distribution of nanocomposites in layered silicates. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposites modified silica sol. Scanning electron microscopy (SEM) was used to examine the morphology of the modified silane coating. The contact angle measurements ensured the hydrophobic behavior of the coatings. The corrosion behavior was investigated using Electrochemical Impedance Spectroscopy (EIS). This study has led to a better understanding of active anticorrosive coatings with embedded nanocomposites and the factors influencing the anticorrosion performance.     

The role of arginines in stabilizing the active open-lid conformation ofRhizomucor miehei lipase

Molecular dynamics simulations for the lid covering the active site ofRhizomucor miehei lipase [EC 3.1.1.3] postulated that, among other interactions, Arg86 in the lid stabilized the open-lid conformation of the protein by multiple hydrogen bonding to the protein surface. Chemical modification of arginine residues inR. miehei lipase with 1,2-cyclohexanedione or phenylglyoxal resulted in residual activities in the hydrolysis of tributyrin of 66 and 46%, respectively. Tryptic maps of native and phenylglyoxal-reactedR. miehei lipase showed that Arg86 was the residue modified most, when the lipase was inhibited to the greatest extent. Guanidine, a structural analog to an arginine side chain, inhibited both the natibe enzyme and the arginine-modified enzymes, resulting in residual activities of 26% as compared to the native enzyme. The inhibition was not an effect of enzyme denaturation. The native enzyme was also inhibited by 1-ethylguanidine, benzamidine and urea, but to a lesser degree than by guanidine. Lipases fromHumicola lanuginosa and porcine pancreas in 100 mM guanidine showed residual activities of 88 and 70%, respectively. The lipases fromCandida antarctica, C. rugosa, Pseudomonas cepacia andP. fluoresences were not inhibited by guanidine. The inhibition ofR. miehei lipase by structural analogs of the arginine side chain and after chemical modification of arginine residues suggest a role of an arginine residue in stabilizing the active open-lid conformation of the enzyme.