柑橘大实蝇生物、生态学及辐照不育技术最新研究进展

柑橘大实蝇是柑橘类果树的一种重要害虫,近几年在我国柑橘种植区的危害呈上升趋势,给柑橘产业造成了巨大损失。本文概述了环境因素包括温度、光周期、营养状况(饥渴)以及水淹对柑橘大实蝇生物学特性和成虫行为的影响,柑橘大实蝇成虫和幼虫人工饲养技术参数,柑橘大实蝇蛹滞育机制,辐照不育关键技术包括最佳辐照剂量和辐照时期,及其在湖北柑橘园柑橘大实蝇防控中的应用与示范情况等,并指出了尚需进一步开展的研究内容。     

Adverse effects of fluorescent dust marking on the behavior of western black widow spiderlings

Fluorescent dust marking is commonly employed to identify and track small arthropods for studies of ecology, demography, and behavior. Despite its widespread use, no study to date has empirically tested the suitability of dust marking for studies of spider behavior. Here, we test the effects of fluorescent dust marking on proximity of cohabitation, sibling cannibalism, and non‐cannibalistic mortality of western black widow spiderlings, Latrodectus hesperus Chamberlin & Ivie (Araneae: Theridiidae). Results indicate that dust‐marked spiderlings cohabitated at closer proximities and died sooner than undusted spiderlings due to a greater incidence of cannibalism in the dust‐marked group. Thus, we conclude that fluorescent dust marking significantly affected the cohabitation and cannibalistic behavior of L. hesperus spiderlings. Although few studies have reported adverse effects of dust marking on arthropods, our results should serve as a warning to future studies that normal behavior may be disrupted by the use of these fluorescent dust markers. Therefore, preliminary testing should be routine when determining the suitability of any marking technique for not only new species, but also new life stages and behaviors.     

鹤顶兰胚囊发育过程中Ca~（2＋）分布的超微细胞化学定位（英文）

用焦锑酸盐沉淀法对鹤顶兰（Phaius tankervilliae）胚囊发育过程中的Ca2＋状态进行超微细胞化学定位。观察结果发现：功能大孢子时期,珠孔端的胚囊壁上开始出现小颗粒的Ca2＋沉淀,但功能大孢子细胞内未见明显的Ca2＋标记;四核胚囊时期胚囊壁上的Ca2＋沉淀明显增多,液泡膜上有Ca2＋沉淀出现,珠孔处的Ca2＋沉淀颗粒较大;成熟胚囊时期,胚囊壁上的Ca2＋沉淀进一步增多,且胚囊内Ca2＋分布明显增多,且极性明显,珠孔端助细胞、卵细胞比合点端反足细胞有更多的Ca2＋沉淀。鹤顶兰成熟胚囊内Ca2＋积累的来源有：（1）在胚囊成熟前主要由珠被细胞、珠细胞通过胞间连丝向胚囊运输;（2）以沉淀有大量Ca2＋的小泡形式跨过胚囊壁进入胚囊。     

Determination of the absolute configurations of synthetic daunorubicin analogues using vibrational circular dichroism spectroscopy and density functional theory

The absolute configurations of three synthesized anthracycline analogues have been determined using vibrational circular dichroism (VCD) spectroscopy and the density functional theory (DFT) calculations. The experimental VCD spectra of the three compounds have been measured for the first time in the film state, prepared from their CDCl₃ solutions. Conformational searches for the monomers and some dimers of the three compounds have been performed at the DFT level using the B3LYP functional and the 6‐311G** and 6‐311++G** basis sets. The corresponding vibrational absorption and VCD spectra have been calculated. The good agreement between the experimental and the calculated spectra allows one to assign the absolute configurations of the three compounds with high confidence. In addition, the dominant conformers of the three compounds have also been identified. Chirality, 2010. © 2010 Wiley‐Liss, Inc.     

Superoxide dismutases—a review of the metal-associated mechanistic variations

Superoxide dismutases are enzymes that function to catalytically convert superoxide radical to oxygen and hydrogen peroxide. These enzymes carry out catalysis at near diffusion controlled rate constants via a general mechanism that involves the sequential reduction and oxidation of the metal center, with the concomitant oxidation and reduction of superoxide radicals. That the catalytically active metal can be copper, iron, manganese or, recently, nickel is one of the fascinating features of this class of enzymes. In this review, we describe these enzymes in terms of the details of their catalytic properties, with an emphasis on the mechanistic differences between the enzymes. The focus here will be concentrated mainly on two of these enzymes, copper, zinc superoxide dismutase and manganese superoxide dismutase, and some relatively subtle variations in the mechanisms by which they function.     

Determination of haloacetic acids in human urine by headspace gas chromatography–mass spectrometry

Haloacetic acids (HAAs) are water disinfection byproducts (DBPs) formed by the reaction of chlorine oxidizing compounds with natural organic matter in water containing bromine. HAAs are second to trihalomethanes as the most commonly detected DBPs in surface drinking water and swimming pools. After oral exposure (drinking, showering, bathing and swimming), HAAs are rapidly absorbed from the gastrointestinal tract and excreted in urine. Typical methods used to determine these compounds in urine (mainly from rodents) only deal with one or two HAAs and their sensitivity is inadequate to determine HAA levels in human urine, even those manual sample preparation protocols which are complex, costly, and neither handy nor amenable to automation. In the present communication, we report on a sensitive and straightforward method to determine the nine HAAs in human urine using static headspace (HS) coupled with GC–MS. Important parameters controlling derivatisation and HS extraction were optimised to obtain the highest sensitivity: 120 μl of dimethylsulphate and 100 μl of tetrabutylammonium hydrogen sulphate (derivatisation regents) were selected, along with an excess of Na₂SO₄ (6 g per 12 ml of urine), an oven temperature of 70 °C and an equilibration time of 20 min. The method developed renders an efficient tool for the precise and sensitive determination of the nine HAAs in human urine (RSDs ranging from 6 to 11%, whereas LODs ranged from 0.01 to 0.1 μg/l). The method was applied in the determination of HAAs in urine from swimmers in an indoor swimming pool, as well as in that of non-swimmers. HAAs were not detected in the urine samples from non-swimmers and those of volunteers before their swims; therefore, the concentrations found after exposure were directly related to the swimming activity. The amounts of MCAA, DCAA and TCAA excreted from all swimmers are related to the highest levels in the swimming pool water.     

临床新技术评价指标体系的建立及应用研究

目的 建立科学的临床新技术评价指标体系,为临床新技术管理提供依据。方法 结合管理实践,通过文献及政策调研、专家咨询、实践验证等方法进行研究。结果 建立了临床新技术定性与定量相结合的评价指标体系,采取同行函审和集中评定相结合的办法进行了实证研究,探索了临床新技术管理的有效方法。结论 评价体系的建立和应用为临床新技术的科学管理提供了依据,推动医疗技术的进步和医院的发展。     

The effect of mass‐rearing on death‐feigning behaviour in the sweet potato weevil (Coleoptera: Brentidae)

The aim of our study was to examine the effect of mass‐rearing, in which there is no exposure to predators, on antipredator traits of insects for improving sterile insect technique programs. The duration of death‐feigning (antipredator behaviour) in sweet potato weevil Cylas formicarius (Summers) (Coleoptera: Brentidae) after mass‐rearing for 71 generations were compared with those in wild strain. There was no significant difference in the duration of death‐feigning between wild and mass‐reared strains. This indicated that the death‐feigning behaviour of mass‐reared strain was maintained for 71 generations even in the absence of predators. We discuss the reasons why death‐feigning behaviour is maintained after mass‐rearing.     

Activity patterns of Queensland fruit flies (Bactrocera tryoni) are affected by both mass‐rearing and sterilization

Mass‐reared sterile tephritid flies released in sterile insect technique (SIT) programmes exhibit behaviour, physiology and longevity that often differ from their wild counterparts. In the present study, video recordings of flies in laboratory cages are used to determine whether the sequential processes of mass‐rearing and sterilization (using gamma radiation) that are integral to SIT affect general activity patterns of male and female Queensland fruit flies Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) (‘Q‐flies'). Compared with wild flies, mass‐reared flies exhibit a marked reduction in overall activity, and further reduction is found after sterilization. In terms of the frequency of activities, both fertile and sterile mass‐reared Q‐flies fly less often and exhibit more bouts of inactivity and grooming than wild Q‐flies. In addition, in terms of the duration of activities, fertile and sterile mass‐reared Q‐flies spend less time flying and more time walking, grooming and being inactive than wild Q‐flies. Although fertile and sterile mass‐reared flies are similar in other regards, sterile mass‐reared flies spend more time being inactive than fertile mass‐reared flies. These findings raise new questions about how changes in behaviour and activity levels may influence the performance of mass‐reared sterile Q‐flies in the field, as well as the physiological and metabolic processes that are involved. The frequency and duration of inactivity could provide a simple but powerful and biologically relevant test for quality in mass‐rearing and SIT programs.     

Electrical signals and their physiological significance in plants

Electrical excitability and signalling, frequently associated with rapid responses to environmental stimuli, are well known in some algae and higher plants. The presence of electrical signals, such as action potentials (AP), in both animal and plant cells suggested that plant cells, too, make use of ion channels to transmit information over long distances. In the light of rapid progress in plant biology during the past decade, the assumption that electrical signals do not only trigger rapid leaf movements in 'sensitive' plants such as Mimosa pudica or Dionaea muscipula, but also physiological processes in ordinary plants proved to be correct. Summarizing recent progress in the field of electrical signalling in plants, the present review will focus on the generation and propagation of various electrical signals, their ways of transmission within the plant body and various physiological effects.