Biosensitive element in the form of immobilized luminescent photobacteria for detecting ecotoxicants in aqueous flow‐through systems

We demonstrated the possibility of long‐term and efficient application of a biosensitive element (BE) in the form of Photobacterium phosphoreum photobacteria immobilized in poly(vinyl alcohol) (PVA) cryogel for detecting various ecotoxicants ( Zn ^{2 +} , Cu ^{2 +} , Hg ^{2 +} , Pb ^{2 +} , 2,4‐dichlorophenoxyacetic acid, 2,6‐dimethylphenol, pentachlorophenol, coumaphos, malathion, chlorpyrifos and methyl parathion) in flow‐through media. The range of detectable concentrations of ecotoxicants was determined at 1 × 10 ^?8 to 1 × 10 ^?4 M for heavy metal ions and at 1 × 10 ^?8 to 1 × 10 ^?5 M for phenol derivatives and organophosphorus pesticides. Immobilized cells of photobacteria quantitatively reacted with these ecotoxicants; cell sensitivity exhibited no flow rate dependence in the range from 45 to 180 mL/h. At a constant concentration of ecotoxicant in the flow, the bioluminescence quenching profile of immobilized cells demonstrated an integral response. The BE could remain in a flow‐through medium for at least 10 days while retaining 95% of luminescent activity in the absence of ecotoxicants. The BE tested in this work was demonstrated to have a long shelf life (> 60 weeks) at ?80°C without changes in the baseline level of bioluminescence. Copyright © 2016 John Wiley & Sons, Ltd.     

Adaptable mesocosm facility to study oil spill impacts on corals

Although numerous studies have been carried out on the impacts of oil spills on coral physiology, most have relied on laboratory assays. This scarcity is partly explained by the difficulty of reproducing realistic conditions in a laboratory setting or of performing experiments with toxic compounds in the field. Mesocosm systems provide the opportunity to carry out such studies with safe handling of contaminants while reproducing natural conditions required by living organisms. The mesocosm design is crucial and can lead to the development of innovative technologies to mitigate environmental impacts. Therefore, this study aimed to develop a mesocosm system for studies simulating oil spills with several key advantages, including true replication and the use of gravity to control flow‐through that reduces reliance on pumps that can clog thereby decreasing errors and costs. This adaptable system can be configured to (a) have continuous flow‐through; (b) operate as an open or closed system; (c) be fed by gravity; (d) have separate mesocosm sections that can be used for individual and simultaneous experiments; and (e) simulate the migration of oil from ocean oil spills to the nearby reefs. The mesocosm performance was assessed with two experiments using the hydrocoral Millepora alcicornis and different configurations to simulate two magnitudes of oil spills. With few exceptions, physical and chemical parameters remained stable within replicates and within treatments throughout the experiments. Physical and chemical parameters that expressed change during the experiment were still within the range of natural conditions observed in Brazilian marine environments. The photosynthetic potential (F_v/F_m) of the algae associated with M. alcicornis decreased in response to an 1% crude‐oil contamination, suggesting a successful delivery of the toxic contaminant to the targeted replicates. This mesocosm is customizable and adjustable for several types of experiments and proved to be effective for studies of oil spills.     

Phylogenetic evidence of a rapid radiation of pleurocarpous mosses (Bryophyta)

Abstract Pleurocarpous mosses, characterized by lateral female gametangia and highly branched, interwoven stems, comprise three orders and some 5000 species, or almost half of all moss diversity. Recent phylogenetic analyses resolve the Ptychomniales as sister to the Hypnales plus Hookeriales. Species richness is highly asymmetric with approximately 100 Ptychomniales, 750 Hookeriales, and 4400 Hypnales. Chloroplast DNA (cpDNA) sequences were obtained to compare partitioning of molecular diversity among the orders with estimates of species richness, and to test the hypothesis that either the Hookeriales or Hypnales underwent a period (or periods) of exceptionally rapid diversification. Levels of biodiversity were quantified using explicitly historical "phylogenetic diversity" and non-historical estimates of standing sequence diversity. Diversification rates were visualized using lineage-through-time (LTT) plots, and statistical tests of alternative diversification models were performed using the methods of Paradis (1997). The effects of incomplete sampling on the shape of LTT plots and performance of statistical tests were investigated using simulated phylogenies with incomplete sampling. Despite a much larger number of accepted species, the Hypnales contain lower levels of (cpDNA) biodiversity than their sister group, the Hookeriales, based on all molecular measures. Simulations confirm previous results that incomplete sampling yields diversification patterns that appear to reflect a decreasing rate through time, even when the true phylogenies were simulated with constant rates. Comparisons between simulated results and empirical data indicate that a constant rate of diversification cannot be rejected for the Hookeriales. The Hypnales, however, appear to have undergone a period of exceptionally rapid diversification for the earliest 20% of their history.     

A novel marine mesocosm facility to study global warming,water quality,and ocean acidification

We describe a completely randomizable flow‐through outdoor mesocosm for climate change and ecotoxicology studies that was built with inexpensive materials. The 16 raceway tanks allow up to 6× water renewal per hour, avoiding changes in natural abiotic seawater conditions. We use an open‐source hardware board (Arduino) that was adapted to control heaters and an innovative CO₂ injection system. This system reduced seawater pH up to ?0.9 units and increased temperature up to +6°C in three treatments and a control. Treatments can be continuously compared with the control and vary according to diel fluctuations, thus following the diel range observed in the sea. The mesocosm facility also includes an integrated secondary system of 48 aquaria for ecotoxicology studies. We validated the reproducibility and relevance of our experimental system by analyzing the variation of the total DNA of the microbial community extracted from corals in three elevated temperature scenarios during a 40‐day experiment. We also present data from temperature, acidification, and copper contamination trials, which allowed continuous, reliable, and consistent treatment manipulations.     

腰椎多节段退变性滑脱的手术治疗

目的:研讨腰椎多节段退变性滑脱手术减压和植骨融合方式与疗效的关系。方法:20例腰椎多节段退变性滑脱患者行后路椎弓根螺钉复位内固定后,采用椎管减压、神经根松解,行椎间植骨和后外侧植骨融合术,采用日本整形外科学会(JOA)下腰痛评分标准评价疗效。结果:获得连续随访者18例,随访时间9月～3年,平均24个月,优良率90%。结论:可靠的内固定、复位,神经根松解,椎间植骨融合治疗腰椎多节段退变性滑脱效果满意,充分的神经根松解是手术治疗的关键。     

Minimally invasive transabdominal collection of preimplantation embryos from the common marmoset monkey (Callithrix jacchus)

A novel, minimally invasive, transabdominal embryo collection method (transabdominal method) was developed as an alternative to a standard abdominal incision for embryo collection in the common marmoset. The abdominal incision method was used for 304 flushes using 36 female animals, whereas the transabdominal method was used for 488 flushes using 48 females; successful embryo collection rates were 48.0% and 48.4% (P > 0.05), respectively. These techniques were successfully duplicated at another institute (German Primate Center, DPZ). At that institution, successful embryo collection rates were 88.9% and 77.8% for the abdominal incision and transabdominal methods, respectively (P > 0.05), whereas the average numbers of preimplantation embryos obtained per flush were (mean ± SD) 1.91 ± 0.35 and 1.71 ± 0.14 (P > 0.05). The transabdominal method reduced animal stress, did not require incisional wound healing, and enabled successive embryo recoveries to be done much sooner. More embryos in early developmental stages (zygotes/morulae) were recovered using the transabdominal method (76.1%) than the abdominal incision method (52.6%, P < 0.01). In contrast, recovery of arrested or abnormal embryos was not significantly different between these two methods (9.8% and 8.3%). To verify developmental ability of embryos recovered by the transabdominal method, transfer of 28 normal embryos to 14 surrogate mothers yielded a nidation rate of 57%. Five females sustained term pregnancies and eight neonates were born. This novel transabdominal method will facilitate progress in marmoset developmental biology and embryology.     

生物制氢及其与以海水为介质的高盐有机废水处理的耦合研究

当前,全球能源系统的主体是＂碳基能源＂——石油和煤等。这些不可再生的资源已日渐枯竭,而且大量使用会破坏地球生态系统。因此,用＂氢基能源＂逐步取代＂碳基能源＂已成为发达国家能源战略的首选目标,有的国家甚至将这一目标定在本世纪中叶。对于中国等发展中国家,大力开发生物质能等新的可再生＂碳基能源＂,同时加速发展＂氢基能源＂,争取提前进入氢能时代,才能实现可持续发展,甚至跨越式发展。制氢技术包括非生物制氢和生物制氢。非生物制氢目前已小量生产和应用,生物制氢的研究也有相当长的时间,其中影响生物制氢进入实用的主要因素是能耗和生产成本过高。因此,如果作为一个孤立的技术系统,生物制氢只能作为战略性项目。首先介绍了生物制氢的主要原理、目前限制生物制氢产业化的关键限制因子;提出了从系统论的原理出发,通过技术集成,突破生物制氢成本的＂瓶颈＂,达到环保和资源利用的双重目的,使其提前实用化;最后,重点阐述了以海水为介质的高盐有机废水的生物制氢技术的研究进展,尤其介绍我国在相关方面的研究进展。     

抗菌肽对细菌杀伤作用的分子机制

抗菌肽是一类新型的抗菌物质,从最低等的生物病毒、细菌到高等的动植物都有广泛分布. 以往的研究主要集中于抗菌肽对细菌细胞膜的作用机制,已经构建了三种作用模式. 但近几年的研究表明,很多抗菌肽都能有效地穿过细菌的细胞膜,直接与胞内分子相互作用,并不引起膜的破裂. 抗菌肽根据其结构特点有着多种杀菌穿膜的机制,其后分别与胞内的靶分子如核酸,蛋白质,信号转导通路等互相作用,最终实现对细菌的杀伤作用.     

CCC在马铃薯试管苗越夏中的作用

CCC不仅对马铃薯试管苗有壮苗作用,还可延缓试管苗的衰老;500mg·L-1的CCC对Atlantic试管苗越夏是有利的.