壳聚糖对尿路感染主要病原菌的体外抑制作用

为研究壳聚糖对尿路感染主要病原菌的抑制效果,采用纸片扩散法测定壳聚糖对大肠杆菌、金黄色葡萄球菌、肺炎克雷伯杆菌、铜绿假单胞菌的抑菌活性,固体平板培养基稀释法确定最小抑菌浓度,比浊法测定细菌的生长曲线并计算壳聚糖对细菌生长的抑制率。结果表明,壳聚糖对大肠杆菌、金黄色葡萄球菌、肺炎克雷伯杆菌、铜绿假单胞菌均具有抑制作用,且抑制作用与其浓度呈正比,最小抑菌浓度为0.05%,抑制效果依次为:金黄色葡萄球菌≥肺炎克雷伯菌大肠杆菌≥铜绿假单胞菌,还能延长4种菌生长的调整期,并使它们在对数期出现之前就已基本停滞生长。     

D-异抗坏血酸苯甲酸酯的合成及其抗氧化和抗菌性能

通过酰氯法由苯甲酰氯和D-异抗坏血酸合成了标题化合物,产物的结构经过FT-IR和1HNMR得以确认。用POV法评价了产物在茶籽油中的抗氧化性能,用MTT法测试了产物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌和铜绿假单胞菌的抗菌作用。结果表明,标题化合物具有明显的抗氧化效果,对大肠杆菌、枯草芽孢杆菌和铜绿假单胞菌的生长有明显的拟制作用。     

曼陀罗总生物碱抑菌活性的初步研究

采用MIC和纸片法考查了曼陀罗提取物对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和酵母菌的抑菌性能。结果表明,曼陀罗对4种受试菌株都有抑菌活性;100℃时,水提物对大肠杆菌的抑菌效果最好,最大抑菌圈为14.72 mm;pH值为8时,曼陀罗水提取对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和酵母菌的抑菌性最好,最大抑菌圈分别为15.46、13.47、12.26和11.22 mm。曼陀罗水提取对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌和酵母菌的最小抑菌浓度(MIC)分别为8、8、4、6 mg/m L。     

生漆漆液对三种常见菌的抑制作用初步研究

以金黄色葡萄球菌、大肠杆菌及铜绿假单胞菌为供试菌,对湖北恩施巴东野三关出产的生漆漆液进行抑菌性实验。实验结果显示,金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌三种常见菌,在分别培养0、1、2、4、24小时后观察,发现生漆漆液对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌均具有抑菌效果,其中对金黄色葡萄球菌的抑菌效果最好。通过对生漆漆液抑菌性试验结果,为生漆在各种实用器具方面的开发利用提供参考。     

川葵精油的制备及杀菌性能研究

以同时蒸馏法提取川葵精油,经GC-MS分析检测得川葵挥发精油的主要成分为异硫氰酸酯类(ITCs);采用滤纸片法和肉汤稀释法研究其抑菌作用,结果表明,川葵精油对金黄色葡萄球菌、白色葡萄球菌、枯草芽孢杆菌、铜绿假单胞杆菌、沙门氏菌、宋内志贺氏菌、大肠杆菌、青霉菌表现出有不同强度的抑制作用,对8种供试菌的最小抑菌浓度为64～256 mg/mL,川葵精油具有一定的杀菌效果。     

鼠李糖乳杆菌发酵提取物在护肤乳液中的抑菌性研究

采用鼠李糖乳杆菌为发酵培养菌株,在特定生长培养基中进行鼠李糖乳杆菌发酵并提取抗菌活性物,凯氏定氮法测定其蛋白质含量为0.246 4%。抑菌实验表明,该提取物对大肠埃希菌、金黄色葡萄球菌及铜绿假单胞菌具有一定的抑菌性能;将提取物用于护肤乳液,添加5%提取物的乳液对大肠埃希菌、金黄色葡萄球菌及铜绿假单胞菌具有较强的抑制能力。     

田基黄总黄酮提取物的抑菌性能研究

用抑菌圈法考察了田基黄总黄酮浓度、pH和处理温度对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌的抑菌活性.结果表明,总黄酮提取物对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌都具有良好的抑菌活性,最小抑菌浓度分别为3.125,6.25,1.562 5 μg/mL.总黄酮浓度为12.5 μg/mL的田基黄提取物对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌分别在pH为8,7～8和5抑菌活性最大.总黄酮提取液具有较强的耐热性能,在20℃和80℃加热处理30 min后对大肠杆菌、枯草芽孢杆菌和金黄色葡萄球菌的抑菌圈分别为12.8,10.2,11.3 mm和12.0,10.0,10.8 mm.     

番茄茎叶粗提液活性成分抑菌作用的研究

研究了从番茄茎叶中提取的活性物粗提物对常见菌种的抑菌效果,采用5种溶剂对番茄茎叶进行提取,以枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌、蜡状芽孢杆菌、黑曲霉为供试菌,对其粗提液进行抑菌活性测定。发现粗提液活性成分对细菌具有较强的抑制作用,对霉菌的抑菌作用较弱。番茄叶粗提液的抑菌浓度高于番茄茎提液。     

槲皮素抗菌活性的研究

以大肠杆菌、金黄色葡萄球菌等为实验菌株,采用药敏纸片法考察槲皮素的抗菌活性.槲皮素对金黄色葡萄球菌的抗菌效果最好,最低杀菌浓度小于0.0061 μmol·mL-1;对胶质芽孢杆菌抗菌效果次之,最低抑菌浓度小于0.0061 μmol·mL-1;对大肠杆菌、苏云金芽孢杆菌、枯草芽孢杆菌、铜绿假单胞菌也有较为明显的抗菌效果,最低抑菌浓度分别为0.0242 μmol·mL-1、0.0061 μmol·mL-1、0.0485 μmol·mL-1、0.0121 μmol·mL-1,最低杀菌浓度分别为1.5522 μmol·mL-1、6.2086 μmol·mL-1、3.1043 μmol·mL-1、1.5522 μmol·mL-1;对人仓白杆菌无抗菌效果.槲皮素具有广谱抗菌性,并且对革兰氏阴性菌的抗菌作用强于革兰氏阳性菌.     

月桂酰丙氨基酸钠的抑菌性能研究

采用抑菌圈法研究了不同浓度的月桂酰丙氨酸钠对金黄色葡萄球菌、铜绿假单单胞菌、大肠杆菌、酵母以及黑曲霉的抑菌性能。结果表明:月桂酰丙氨酸钠具有一定的抑菌能力,其抑菌能力与其浓度正相关;对黑曲霉菌、酵母菌以及金葡萄球菌的抑菌效果明显,对铜绿假单胞菌的抑菌次之,对大肠杆菌没有抑菌效果。     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

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.     

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.