有机相中刻录脂肪酶聚合物对配体的吸附

以聚乙二醇400二丙烯酸酯和三羟甲基丙烷三甲基丙烯酸酯为原料，加入脂肪酶液，配体月桂酸，表面活性剂，经紫外光聚合和有机溶剂洗脱月桂酸，获得锁定了由配体诱导脂肪酶活性构象的聚合物——刻录脂肪酶聚合物（RLP），对RLP在月桂酸溶液中的吸附行为进行研究，测定了温度在30~50℃ 的吸附等温线。结果表明，RLP对其配体月桂酸的吸附能力远大于空白聚合物对月桂酸的吸附能力, 达到8.7倍。平衡吸附量和平衡浓度的关系符合Langmuir和Freundlich吸附等温方程。     

吉安散装人抗冰战雪保平安——江西吉安散办干部职工铲除冰保畅通纪实

春节前后,吉安市遭遇到罕见的冰冻雨雪灾害天气,连续出现了低温、阴雨和雨夹雪,成为全省灾情最严重地区之一.特别是1月25日以后,出现了持续大范围的雨雪冰冻天气.冰冻损坏了市区的电网,压垮了树枝,封锁了道路和桥梁.     

2010～2011年世界塑料工业进展

收集了2010年7月～2011年6月世界塑料工业的相关资料,介绍了2010～2011年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、ABS树脂),工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚),特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮),通用热固性树脂(酚醛、不饱和聚酯树脂、环氧树脂、聚氨酯)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

花粉症诱因探究

花粉症又称季节性鼻炎或枯草热,是敏感个体对花粉的一种超敏反应.在美国,每一百个人当中就有两个以上的人患花粉症;现在日本有1300万人饱受花粉症折磨,超过总人口的10%[1].我国的发病率为0.5%～1%,高发区达到5%,虽没有上述一些国家那么严重,受害者亦相当可观.全世界花粉症发病人数到1999年就已有5000多万[2],可见花粉症患者是一个绝不可轻视的群体.图1显示了花粉过敏症的发病机制.     

欧文斯科宁专访

欧文斯科宁公司(以下简称OC)创建66年来一直致力于开发玻璃纤维的新用途,是建筑材料和复合材料行业的领先创新者和制造商,OC进入亚太市场也已超过30年,长久以来他们专注于推广复合材料的应用领域以及扩大其供应基地.最近,欧文斯科宁在印度扩充了生产能力,并在上海设立了技术中心.至今为止,欧文斯科宁在亚太区已有超过1800名员工,从事建筑材料和复合材料的生产,销售和研发工作.     

喷涂前处理污染源的分析及其处理措施

随着我国国民经济的快速发展和国家"节能减排"重点项目的深入开展,各种污染源的分析及其处理措施的研究备受关注.本文在充分研究若干家电企业的钢铁喷涂制件的前处理工艺(如:预脱脂、脱脂、清洗、表调、磷化等)的基础上,分析喷涂前处理过程中的污染源,研究污染源的处理措施.     

酿酒酵母细胞表达异源萜类化合物的研究进展

萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。     

2-丁烯合成有机硫化剂的研究

实验以2-丁烯和单质硫为原料,在高温高压催化剂条件下合成有机硫化剂.考察了反应温度、反应时间、硫烯比、催化剂种类以及催化剂用量对硫化剂硫含量的影响,其中重点考察了有机碱性催化剂、无机碱性催化剂、秋兰姆类((CH3)2NCS4CN(CH3))催化剂对硫化剂硫含量的影响.实验结果表明,催化剂对硫含量的影响很大,秋兰姆类和二乙胺催化剂的影响最大,硫含量分别为27.1%和26.64%.     

2006～2007年世界塑料工业进展

收集了2006年7月～2007年6月世界塑料工业的相关资料,介绍了2006～2007年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

回转窑耐火砖的砌筑及使用

我公司回转窑规格为Φ4.0m×60m.窑内使用的耐火砖为镁铬砖、隔热尖晶石、蓝晶石和黏土砖以及硅莫砖.镁铬砖规格为(81×90×150×200)mm,其它耐火砖规格皆为(81×90×200×200)mm.尽管每个品种的砖品质相同,但由于在镶砌和使用过程中方法不同,寿命有长有短.通过多年实践,现总结如下.     

A review of ZrO2 nanoparticles applications and recent advancements

The many branches of nanoscience have made significant strides and advancements during the past ten years, as has the entire scientific community. Zirconia nanoparticles have several uses as adsorbents, nanosensors, nanocatalysts, and other types of nanomaterials. Their outstanding biomedical uses in dental care and drug delivery, as well as their intriguing biological characteristics, such as their anti-cancer, anti-microbial, and antioxidant activity, have further encouraged researchers to investigate their physicochemical properties using various synthetic pathways. Due to the popularity of zirconia-based nanomaterials, the current research comprehensively examines several synthesis techniques and their effects on the composition, dimensions, forms, and morphologies of these nanomaterials. In general, there are two methods for creating zirconia nanoparticles: chemical synthesis, which uses hydrothermal, solvothermal, sol-gel, microwave, solution combustion, and co-precipitation processes; and a greener method, which uses bacteria, fungi, and plant components. The aforementioned techniques have been evaluated in the present review for achieving particular phases and shapes. A thorough analysis of zirconia-based nanomaterial's uses is also included in the review. Furthermore, comparisons with their equivalent composites for various applications as well as the influence of particular phases and morphologies have been added. The final portion includes the summary, future outlook, and potential application.     

Semiochemistry of the Goldeneyed Lacewing Chrysopa oculata: Attraction of Males to a Male-Produced Pheromone

Gas chromatographic-electroantennographic detection (G3C-EAD) experiments showed that antennae of males and females of the goldeneyed lacewing, Chrysopa oculata Say (Co. = Chrysopa), consistently responded to four compounds extracted from the abdominal cuticle of males:nonanal, nonanol, nonanoic acid, and (1R*,2S*,5R*,8R*)-iridodial. These compounds were not detected from abdominal cuticle of females. Thoracic extracts of both sexes contained antennal-stimulatory 1-tridecene and EAD-inactive skatole. Chrysopa oculata adults were most sensitive to (1R,2S,5R,8R)-iridodial standard at an EAD-response threshold between 0.1 and 1 pg, which was 10-100 times lower than thresholds for nonanal and nonanoic acid, and up to 10,000 times lower than thresholds for other compounds tested. A similar EAD response pattern was also found in another Chrysopa sp. (Co. quadripunctata Burmeister). In field-trapping experiments, (1R,2S,5R,8R)-iridodial was the only male-specific compound that attracted Co. oculata males. Males also were weakly attracted to (1R,4aS,7S,7aR)-nepetalactol (an aphid sex pheromone component), probably due to the 5% (1R,2S,5R,8R)-iridodial present in the synthetic sample as an impurity. A herbivore-induced plant volatile, methyl salicylate, increased attraction of males to (1R,2S,5R,8R)-iridodial, whereas 1-tridecene was antagonistic. No females were caught in the entire study. Scanning electron micrographs revealed numerous male-specific, elliptical epidermal glands on the 3rd-8th abdominal sternites of Co. oculata, which are likely the pheromone glands. Another lacewing species, Chrysoperla rufilabris (Burmeister) (Cl. = Chrysoperla), did not produce male-specific volatiles or possess the type of gland presumed to produce pheromone in Co. oculata males, but (Z)-4-tridecene was identified as a major antennal-stimulatory compound from thoracic extracts of both sexes of Cl. rufilabris. Thus, (1R,2S,5R,8R)-iridodial (or its enantiomer) is now identified as a male-produced male aggregation pheromone for Co. oculata, the first pheromone identified for lacewings.     

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined.     

The Emerging Roles of Chromogranins and Derived Polypeptides in Atherosclerosis,Diabetes, and Coronary Heart Disease

Chromogranin A (CgA), B (CgB), and C (CgC), the family members of the granin glycoproteins, are associated with diabetes. These proteins are abundantly expressed in neurons, endocrine, and neuroendocrine cells. They are also present in other areas of the body. Patients with diabetic retinopathy have higher levels of CgA, CgB, and CgC in the vitreous humor. In addition, type 1 diabetic patients have high CgA and low CgB levels in the circulating blood. Plasma CgA levels are increased in patients with hypertension, coronary heart disease, and heart failure. CgA is the precursor to several functional peptides, including catestatin, vasostatin-1, vasostatin-2, pancreastatin, chromofungin, and many others. Catestatin, vasostain-1, and vasostatin-2 suppress the expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in human vascular endothelial cells. Catestatin and vasostatin-1 suppress oxidized low-density lipoprotein-induced foam cell formation in human macrophages. Catestatin and vasostatin-2, but not vasostatin-1, suppress the proliferation and these three peptides suppress the migration in human vascular smooth muscles. Chronic infusion of catestatin, vasostatin-1, or vasostatin-2 suppresses the development of atherosclerosis of the aorta in apolipoprotein E-deficient mice. Catestatin, vasostatin-1, vasostatin-2, and chromofungin protect ischemia/reperfusion-induced myocardial dysfunction in rats. Since pancreastatin inhibits insulin secretion from pancreatic β-cells, and regulates glucose metabolism in liver and adipose tissues, pancreastatin inhibitor peptide-8 (PSTi8) improves insulin resistance and glucose homeostasis. Catestatin stimulates therapeutic angiogenesis in the mouse hind limb ischemia model. Gene therapy with secretoneurin, a CgC-derived peptide, stimulates postischemic neovascularization in apolipoprotein E-deficient mice and streptozotocin-induced diabetic mice, and improves diabetic neuropathy in db/db mice. Therefore, CgA is a biomarker for atherosclerosis, diabetes, hypertension, and coronary heart disease. CgA- and CgC--derived polypeptides provide the therapeutic target for atherosclerosis and ischemia-induced tissue damages. PSTi8 is useful in the treatment of diabetes.     

A review of liquid silicone rubber injection molding: Process variables and process modeling

Liquid silicone rubber (LSR) is an elastomer molded into critical performance components for applications in medical, power, consumer, automotive, and aerospace applications. This article reviews process behavior, material modeling, and simulation of the (LSR) injection molding process. Each phase of the LSR injection molding process is discussed, including resin handling, plastication, injection, pack and hold, and curing; and factors affecting the molding process are reviewed. Processing behavior of LSR is marked by transient interactions between curing, shear rate, temperature, pressure, and tooling. Therefore, current LSR models for curing, viscosity, pressure, and temperature are discussed. Process dynamics and material modeling are combined in LSR injection molding simulations with applications in mold design, troubleshooting process-induced defects, and management of shear stress and non-uniform temperatures between LSR and substrates during overmolding. Finally, case studies using commercial simulation software are presented, which have shown cavity pressure and flow front advancement within 3% of experimental values. Optimization of LSR materials, data collection, model fitting, venting, and bonding remain areas of continued interest.     

Using symmetry to understand the attributes of color

The common attributes of color are distinguishable by their symmetries. Hue, saturation, chroma, chromaticness, whiteness, and blackness symmetries are discussed. Symmetries are generally not sufficient to specify unique formulas for color attributes, nor are they an endorsement of color model accuracy. However, symmetries do provide constraints for valid formulae, which are useful even when symmetries are only approximate. They also provide an alternate conceptual understanding of color attributes that differs from standard color science definitions. Symmetries provide a simplified framework for calculating groups of colors that share color attributes. Color models examined include the Hunt Model, a simple color model (SCM), various CIE color spaces, and IPT. A general functional form describes symmetries and scaling laws for many color models, and exceptions are discussed. © 2007 Wiley Periodicals, Inc. Col Res Appl, 33, 27–44, 2008     

Potential of Polyvinylidene Fluoride/Carbon Nanotube Composite in Energy,Electronics, and Membrane Technology: An Overview

Polyvinylidene fluoride (PVDF) is a semicrystalline thermoplastic and electroactive polymer with piezoelectric and pyroelectric properties, thermal stability, elasticity, and chemical resistance. PVDF exits in five different phases (α, β, δ, γ, and ε-phase). Unique properties of this polymer enhances its use in chemical, biomedical, and electronic industries such as supercapacitors, transducers, actuators, and batteries. Carbon nanotube (CNT) is used as reinforcement to exploit full potential of PVDF in energy, electronics, and membrane technology. The nanofiller affects morphology, piezoelectric, pyroelectric, electrical, dielectric, thermal, and mechanical properties of PVDF-based nanocomposite. CNT content and chemical modification influence properties as well as application of PVDF.     

Pheromonal activity of single castoreum constituents in beaver,Castor canadensis

Behavioral activity of single components of beaver castoreum was demonstrated for the first time. In four experiments samples were presented to free-ranging beaver in their family territories. First, responses to whole castoreum and anal gland secretion (AGS) from males and females were tested. Second, 24 compounds, known to be constituents of beaver castoreum, were individually screened for activity. Four of these consistently released immediate responses during the observation periods. These are the phenols 4-ethylphenol and 1,2-dihydroxybenzene and the ketones acetophenone and 3-hydroxyacetophenone. In the most complete responses, the beaver sniffed from the water, were attracted to the odor, swam toward its source, went on land, and then approached, sniffed, pawed, and scent-marked the artificial scent mound. 4-Ethoxyphenol, a compound not yet found in castoreum, also released these responses. Five additional compounds resulted in a few delayed visits to the samples during the night following the observations, as evidenced by destroyed scent mounds. These are 4-methyl-1,2-dihydroxybenzene, 4-methoxyacetophenone, 5-methoxysalicylic acid, salicylaldehyde, and 3-hydroxybenzoic acid. Third, mixtures of 24 and six compounds were tested. Responses to these mixtures could be as strong as those to whole castoreum. Fourth, the four regularly active compounds were tested in two additional beaver populations and proved to be active there, too. The response was strongest in the densest beaver population.     

Enhancing the daytime conspicuity of pedestrians through the usage of fluorescent materials

The issue of daytime, pedestrian visibility, especially where occupational activities are involved, can be well served by bringing existing and related knowledge on high-visibility materials together with new product capabilities. Formulated strategically, this information can beneficially serve the personal safety of our society. This particular form of personal safety involves being seen, most critically, by operators of motorized vehicles. Therefore, the issues of visibility, visibility enhancement, and conspicuity are focused upon through the use of high-visibility materials. High-visibility materials include but are not limited to retroreflective forms. In daytime and dusk/dawn conditions, fluorescent-colored products can serve as high-visibility materials used to effectively generate enhanced conspicuity. the time has now come to more aggressively research what we may intuitively believe and then apply this knowledge. to more fully grasp what is involved, we must take into account the following: 1. a basic understanding of fluorescence, 2. basic human vision and perception, 3. situations calling for enhanced conspicuity, 4. strategies for use, 5. product development, 6. specfications, guidelines and standards, 7. public education, and awareness. © 1995 John Wiley & Sons, Inc.     

Analyses of Avocado (Persea americana) Nectar Properties and their Perception by Honey bees (Apis mellifera)

Honey bees are important avocado pollinators. However, due to the low attractiveness of flowers, pollination is often inadequate. Previous work has revealed that avocado honey is relatively unattractive to honey bees when compared with honey from competing flowers. We characterized avocado honey and nectar with respect to their odor, color, and composition of sugars, phenolic compounds, and minerals. Furthermore, we tested how honey bees perceive these parameters, using the proboscis extension response bioassay and preference experiments with free-flying bees. Naïve bees were indifferent to odors of avocado and citrus flowers and honey. Experienced bees, which were collected in the field during the blooming season, responded preferentially to odor of citrus flowers. The unique sugar composition of avocado nectar, which contains almost exclusively sucrose and a low concentration of the rare carbohydrate perseitol, and the dark brown color of avocado honey, had no negative effects on its attractiveness to the bees. Phenolic compounds extracted from avocado honey were attractive to bees and adding them to a solution of sucrose increased its attractiveness. Compared with citrus nectar and nonavocado honey, avocado nectar and honey were rich in a wide range of minerals, including potassium, phosphorus, magnesium, sulfur, iron, and copper. Potassium and phosphorus, the two major minerals, both had a repellent effect on the bees. Possible explanations for the presence of repellent components in avocado nectar are discussed.