抗生素在水环境中的分布及其毒性效应研究进展

近年来,抗生素作为一种新兴污染物,其危害性和污染控制问题已成为人们日益关注的焦点。水环境中抗生素的质量浓度通常在μg/L~ng/L水平,但持续使用排放,残留于水环境中的抗生素会对当地的生态系统产生不良影响,引起水生生物致畸突变,在生物体内富集,同时通过饮水、食物链等方式传递人体,进而危害人类健康。文章综述了抗生素在水和沉积物中的含量水平及其季节变化,简要总结了抗生素对生物的毒性效应,为进一步研究抗生素对人类健康的影响提供可靠依据。     

抗生素抗性基因的污染、危害和控制技术的研究进展

大量抗生素在人类医药业、畜牧养殖业滥用导致了人体或动物体内抗生素抗性基因(ARGs)的产生,受到人们普遍关注。文章综述了抗生素抗性基因在环境中的污染情况。揭示了由抗生素引起的耐药性病原体对人类的危害,同时探讨了消除抗生素抗性基因的技术进展。提出了今后抗生素抗性基因的研究重点和方向。     

抗生素水生生态环境风险评价

抗生素的大量使用造成其在环境中的普遍存在。水体作为抗生素的主要归趋之一,抗生素的水生生态风险受到越来越多的关注。本文阐述了抗生素水体生态风险的问题形成、潜在风险分析、目前国外评价体系及风险表征,结合我国实际提出我国开展抗生素水体生态风险评价的必要性和建议。     

水体中个人护理品的环境浓度和毒性研究进展

个人护理品是一类新兴的有机污染物,能对环境和生物健康构成潜在的危害。关于药物在水环境中的污染现状已经进行了大量的研究,然而,关于比药物更常见、浓度更高的个人护理产品的研究相对较少。个人护理产品不断地释放到水生环境中,具有生物活性和持久性。本文综述了水体中几种典型个人护理品的环境污染现状,及其释放到水生环境的危害。     

污泥干化芦苇床中抗生素抗性基因研究进展

抗生素在畜牧业和水产养殖业的大量使用,造成了严重的环境污染,其诱发产生的抗性基因对环境和生物的危害引起了业内人士的广泛关注。研究者们针对抗生素抗性基因的来源、传播途径以及可能会对人类产生的影响进行了系统的研究。但针对作为抗生素主要储存库之一的污水厂剩余污泥的相关研究较少。随着污泥干化芦苇床技术研究的深入,针对抗生素抗性基因去除及降解转化机制的研究就显得日益重要。本文就抗生素抗性基因在污泥干化芦苇床中的研究前景进行分析和总结。     

帕马霉素N-去甲基化对气生菌丝诱导及生长抑制活性的影响

放线菌产生大量的次级代谢产物，包括抗生素和植物毒素，由放线菌产生的抗生素与形态分化如形成气生菌丝和孢子密切相关，因此，对气生菌丝形成过程的调节会增加抗生素的产量，减少由植物病原性放线菌产生的危害。     

水体污染对人体健康的影响及防治

随着经济和社会的发展,大量生活污水和工业废水排入环境,造成受纳水体污染,严重影响水生生态系统的结构、功能和水资源的利用,还直接危害人类的身体健康。本文从水体污染及其来源、污染物在水体中的迁移转化、对人体的影响等方面做了论述,并提出了防治对策。     

环境水体中的残留抗生素及其潜在风险

针对残留抗生素对环境水体造成的污染及生态毒害问题,从抗生素的生产使用现状及其环境水体中的来源入手,综合分析了抗生素在环境水体中的残留与污染水平,重点研究了抗生素残留对水生生物、人类健康等存在的环境风险,建议开展环境水体中抗生素含量及迁移规律的调查、确定抗生素对生态平衡和生物多样性的影响以及有效去除抗生素的技术方法等的研究重点和方向,从而有效降低环境水体中抗生素潜在安全风险.     

含酚废水处理技术研究进展

石油化工、炼油、焦化等行业不断发展,除了带来经济上的发展,还产生大量的含酚废水,对水体构成严重污染,很难被降解。含酚废水中的主要物质苯酚及其衍生物是一种原生质毒物,不仅对饮用水水源有危害作用,其毒性还会对水生生物产生不利的影响,因此含酚废水的治理不容忽视。国内外学者针对这个问题分别在物理、化学及生物方面进行了研究,提出了吸附、气提、电化学氧化法、还原、生物膜、固定化微生物技术等方法,不断完善含酚废水的处理途径。     

我国水产养殖水体中抗生素的污染特征

近年来,抗生素对水生生态系统的有害效应、抗性基因的传播及其对人类健康的威胁等问题受到广泛关注.由于抗生素在水产养殖业中的广泛应用以及养殖废水中抗生素的低处理效率,养殖废水是地表水中抗生素的主要来源之一.文中综述了近十几年我国水产养殖水体中的抗生素污染特征,以期为水产养殖水体抗生素污染的修复提供理论依据.水产养殖水中主要...     

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.     

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.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。