载银/铜NaA分子筛的制备及抗菌性能研究

探讨了液相离子交换法制备载银/铜NaA分子筛抗菌剂的实验条件,并对载银/铜NaA分子筛样品中载银、铜的含量,抗变色性能及对大肠杆菌、金黄葡萄球菌的抗菌性进行检测。结果表明,与单独载银的NaA分子筛相比,载银/铜NaA分子筛中银和铜含量分别达到5.5%和1.6%,色差更小,抗菌性显著提高。     

载银锌纳米二氧化硅抗菌剂的制备及应用

利用纳米二氧化硅的结构特性,将其作为抗菌剂载体,制成了一种载银锌双组分纳米二氧化硅抗菌剂,研究了提高抗菌剂分散性的方法。结果表明,使用振动磨加分散剂的方法进行分散,可以提高载银锌纳米二氧化硅抗菌剂在涤纶基体中的分散性;该抗菌剂对大肠杆菌及金黄色葡萄球菌的抗菌率达96％以上,且抗菌涤纶具有良好的力学性能。     

纳米载银无机抗菌剂的研究进展

纳米抗菌材料的核心是抗菌剂,纳米载银无机抗菌剂是目前研究最为广泛的抗菌剂之一。对纳米载银无机抗菌剂的抗菌机理和种类作了较为详细的叙述,概述了纳米载银无机抗菌剂的制备方法,最后对纳米载银无机抗菌剂的前景发展进行了预测。     

载银蒙脱石无机抗菌剂的抗菌性能研究

以大肠杆菌、金黄色葡萄球菌、产气杆菌、枯草杆菌、啤酒酵母菌和白色念珠菌作为实验菌株,采用试管振荡试验法,检测载银蒙脱石的抗菌性能,并进行抗菌剂的耐水性和耐久性试验.结果表明:载银量在2.5%～3.0%之间的载银蒙脱石抗菌剂具有良好的抑菌和灭菌性能.载银蒙脱石抗菌剂具有广谱抗菌性,不易分解失效,抗菌时效长,并具有良好的耐水性.     

纳米载银医用TPU抗菌材料的制备及其性能研究

采用熔融共混挤出的方式将纳米载银硅酸盐抗菌剂和医用TPU材料共混制得了医用TPU抗菌材料。研究了纳米载银硅酸盐抗菌剂对医用TPU材料的物理性能、热力学性能的影响,同时通过抗菌活性测试对材料的抗菌性能进行了定量测定。结果表明,当纳米载银抗菌剂的添加量为1.5%时,其在医用TPU材料中仍能够均匀分散,但是出现了部分团聚。抗菌剂的加入对医用TPU材料的硬度影响不大,其拉伸强度和断裂伸长率随着抗菌剂添加量的增多而增大。随着抗菌剂添加量的增多,医用TPU材料的玻璃化转变温度先降低后增大。当抗菌剂的添加量为1.5%时,医用TPU材料对大肠杆菌、金黄色葡萄球菌和白念珠菌这三种菌的抗菌活性值分别达到了5.6、5.2和4.1。     

白炭黑载锌无机抗菌剂制备与性能研究

以白炭黑(无定型SiO2)为载体,采用水浴加热搅拌法,通过白炭黑负载Zn2+制备抗菌剂前驱体和前驱体焙烧固化制备了白炭黑载锌无机抗菌剂,并将其在涂料中添加制备了抗菌涂料.对Zn2+浓度、白炭黑固含量、混合液pH值、焙烧温度、焙烧时间等抗菌剂制备条件进行了试验考察和优化,对白炭黑载锌无机抗菌剂和抗菌涂料性能进行了测试表征.结果表明,白炭黑载锌无机抗菌剂和抗菌涂料均具有良好的抑菌性,其中,白炭黑载锌无机抗菌剂最小抑菌浓度为:对大肠杆菌19 mg/mL,对金黄色葡萄球菌6 mg/mL;添加8wt%白炭黑载锌无机抗菌剂涂料抗菌率为:对大肠杆菌90.48%,对金黄色葡萄球菌98.77%.     

载银黄腐酸抗菌剂的合成及抗菌性研究

研究了载银黄腐酸抗菌剂的制备及其抗菌效果。通过在水溶液中黄腐酸与银粒子之间的络合作用得到了载银黄腐酸抗菌剂。红外光谱分析表明黄腐酸与Ag~+粒子发生了络合反应。热重分析结果显示载银黄腐酸的热稳定性大大提高。将载银黄腐酸抗菌剂添加到聚乙烯醇中得到了抗菌塑料。抗菌实验表明加入载银黄腐酸抗菌剂的聚乙烯醇塑料对枯草杆菌和大肠杆菌均表现出良好的抗菌性能。     

TiO2/SiO2载银抗菌粉体的制备及抗菌性能研究

采用原位掺杂和物理吸附2种方法,成功制备了TiO2/SiO2复合载体载银抗菌粉体;系统考察了制备工艺、煅烧、掺锌等因素对复合载银抗菌粉体的影响。利用XRD、SEM等多种测试手段,对复合载银抗菌剂的白度、结构及形貌进行了表征;并以污水细菌为探针,考察了复合载体载银抗菌剂的抗菌性。结果表明:原位掺杂和物理吸附2种方法均能得到相同结构的复合载体载银抗菌剂,掺锌能有效增加载银抗菌剂样品的白度,提高抗菌剂的色泽稳定性;抗菌性能测试表明,复合载银粉体对污水细菌具有较强的抗菌效果,最小抗菌浓度为450 mg/L。     

Zn杂化NaA分子筛的合成及其抗菌性能

以硅溶胶、偏铝酸钠、硝酸锌为原料,采用单模微波合成法制备Zn杂化NaA分子筛。对制备的Zn杂化NaA分子筛样品进行了表征;以Zn杂化NaA分子筛为载体制备载银分子筛,研究其抗菌性能。结果表明:Zn同晶取代了部分Al进入分子筛骨架得到Zn杂化NaA分子筛;其载银量为(43.26±0.48)%,对大肠杆菌的最小抑菌浓度(MIC)为7.92×10–6,具有良好的缓释性和抗变色性。Zn杂化载银分子筛的抗菌方式是分子筛负载Ag+的溶出接触式杀菌和Ag+催化产生·OH氧化还原杀菌的共同作用。     

静电纺丝制备载银海藻酸钠/聚乙烯醇复合纳米纤维膜敷料及其性能研究

本文以海藻酸钠和聚乙烯醇为原料,以磷酸锆钠银为抗菌剂,通过静电纺丝工艺制备载银海藻酸钠/聚乙烯醇复合纳米纤维膜敷料,同时,对制备的载银海藻酸钠/聚乙烯醇复合纳米纤维膜敷料的吸液完整性、力学性能、抗菌性、细胞毒性进行研究。结果显示,载银海藻酸钠/聚乙烯醇复合纳米纤维膜敷料具有很好的力学性能以及抗菌效果,且细胞毒性较低,对大肠杆菌的抑菌率为99.98%,证明适合用作医用敷料。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外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、环氧树脂、不饱和聚酯树脂)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。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.