Absorption of gamma-emitting fission products and activation products by rice under flooded and unflooded conditions from two tropical soils

Summary The absorption of gamma-emitting fission products¹⁰⁶Ru,¹²⁵Sb,¹³⁷Cs and¹⁴⁴Ce and activation products⁵⁹Fe,⁵⁸Co.⁵⁴Mn and⁶⁵Zn by rice plants grown on two contrasting tropical soils, namely, a blak soil (pellustert) and a laterite (oxisol), and the effects of flooding were studied under controlled conditions. Results indicated greater uptake of¹⁰⁶Ru and¹²⁵Sb from the black soil than from the laterite. In contrast, the uptake of¹⁴⁴Ce and¹³⁷Cs was greater in the laterite than in the black soil. Flooding treatment enhanced the uptake of all these fission products by rice plants in the laterite soil whereas this effect was observed only for¹²⁵Sb and¹³⁷Cs in the black soil.The plant uptake of activation products from the two soil types showed maximum accumulation of⁶⁵Zn followed by⁵⁴Mn,⁵⁹Fe and⁵⁸Co in both soil types. Besides, uptake of these nuclides was greater from the laterite soil than from the black soil. Flooding treatment for rice while showing a reduction of⁵⁹Fe uptake, showed an increase in plant uptake of⁵⁸Co,⁵⁴Mn and⁶⁵Zn in both soil types.     

Effects of aplysia hemocyanin on the conductance of oxidized cholesterol black lipid membranes

Treating oxidized cholesterol black lipid membranes with Aplysia hemocyanin induces the formation of channels with two conductivity states; at the fundamental level of conductance, the lifetime is several hours. Transitions from this state to a different conductivity state occur. Membranes with many of these channels have a voltage-dependent conductance and transitions between different conductivity values occurring in a few ms. Thus molluscan hemocyanins can be considered as a general class of pore-forming proteins.     

Yeasts and yeast-like fungi in tap water and groundwater,and their transmission to household appliances

In the present study we describe the occurrence of fungi in 100 tap water and 16 groundwater samples from Slovenia. We used culture-dependent and culture-independent techniques. 28 fungal species belonging to 16 genera were isolated with selected culturing conditions, targeting human opportunistic yeasts and yeast-like fungi. Of special concern was the detection of Aureobasidium melanogenum, Exophiala dermatitidis, Rhinocladiella similis, Candida parapsilosis and Rhodotorula mucilaginosa. The DGGE analysis of ITS1 rDNA revealed from 6 to 16 bands hypothetically corresponding to different taxa, while pyrosequencing showed the presence of Aspergillus and Exophiala. According to the statistic machine learning methodology, the profile of fungi in water is determined by the concentration of calcium and magnesium ions and the presence of nitrate. Exophiala spp., C. parapsilosis and R. mucilaginosa are known as dominant contaminants of household appliances. It appears that they are transferred with water to dishwashers and washing machines, where they subsequently proliferate.     

黑水虻卵胚胎发育过程及在生产上的应用

黑水虻作为近年来广受关注的资源昆虫,其规模化应用的基础理论研究成为热点。本文对其胚胎发育过程进行研究,利用显微镜对资源昆虫黑水虻卵孵化发育过程进行观察并拍照,对胚胎各个时期的发育时间和形态进行记录。试验发现,在32℃下,黑水虻卵的发育历期为51 h。黑水虻的胚胎发育经过卵裂期、胚盘胚带形成期、原肠形成期、胚体分节期、体壁形成期、器官形成期6个典型时期。试验对孵化过程中的15个具体发育时期的特征和发育时间进行记录,形成了一套虫卵镜检技术应用于实际生产。在生产上,通过镜检技术对每一批次待孵化虫卵进行镜检观察,可初步判定该批次待孵化虫卵所处的发育阶段和死亡率,预估虫卵孵化时间和孵化率,为规模化稳定培育黑水虻苗种提供理论依据。     

不同含水率饲料对黑水虻生长发育的影响及其对饲料的转化特征研究

饲料的含水率是影响黑水虻生长发育及其对饲料养分转化的重要因素,本研究旨在探究黑水虻生物转化过程中饲料最佳含水率。将3龄黑水虻幼虫接入含水率为40%、50%、60%、70%、80%的饲料中,每隔3 d记录黑水虻的体重,至预蛹数达总数的50%时结束试验,计算预蛹历期、预蛹总产量及有效转化率,测定黑水虻及饲料残渣养分及总能。结果发现：1）黑水虻预蛹总产量及其对饲料的有效转化率随水分含量升高而线性增加,在80%水分下达到最大值。2）黑水虻在70%水分下最先预蛹,预蛹历期为14 d。3）黑水虻体内CP含量随水分含量增加而线性下降,EE、GE含量随水分增加线性上升。4）黑水虻对饲料GE的代谢消耗率在60%水分下最高,而在80%水分下对饲料养分的累积量最高。因此,生产中为了高效运转黑水虻生物转化体系,应根据生产目的调节饲料水分以获取最大效益。     

Identification of a potent Angiotensin-I converting enzyme inhibitory peptide from Black cumin seed hydrolysate using orthogonal bioassay-guided fractionations coupled with in silico screening

Black cumin (Nigella sativa) seed protein (BCSP) was individually hydrolyzed with pepsin, trypsin, and α-chymotrypsin. After ultrafiltration, the α-chymotrypsin hydrolysate (< 3 kDa) exhibited the highest ACE inhibitory (ACEI) activity with an IC₅₀ value of 34.4 ± 1.5 μg/mL. This hydrolysate was orthogonally fractionalized using reversed-phase high-performance liquid chromatography (RP-HPLC) and strong cation exchange (SCX) chromatography, and the most active RP-HPLC and SCX fractions (F7 and H4, respectively) were individually screened out by ACEI assay. These two fractions were analyzed with liquid chromatography-tandem mass spectrometry (LC–MS/MS) followed by automated de novo peptide sequencing, and totally 43 ACEI candidate peptides were identified. Three overlapping peptides (VTPVGVPKW, VVTPVGVPKW, and LVLTL) were simultaneously contained in both fractions, and VTPVGVPKW (VW-9) was speculated as to the most potent ACEI peptide based on the in silico analysis. Synthetic VW-9 was used to confirm the identity, and a remarkable IC₅₀ value of VW-9 (1.8 ± 0.09 μM) was determined. Preincubation and inhibition mechanism studies indicated that VW-9 was a true inhibitor as well as a non-competitive inhibitor on ACE, which was further illustrated with the molecular docking simulation. Our study revealed that the application of VW-9 to antihypertensive products is promising.     

Evaluating the effectiveness of retention forestry to enhance biodiversity in production forests of Central Europe using an interdisciplinary,multi‐scale approach

Retention forestry, which retains a portion of the original stand at the time of harvesting to maintain continuity of structural and compositional diversity, has been originally developed to mitigate the impacts of clear‐cutting. Retention of habitat trees and deadwood has since become common practice also in continuous‐cover forests of Central Europe. While the use of retention in these forests is plausible, the evidence base for its application is lacking, trade‐offs have not been quantified, it is not clear what support it receives from forest owners and other stakeholders and how it is best integrated into forest management practices. The Research Training Group ConFoBi (Conservation of Forest Biodiversity in Multiple‐use Landscapes of Central Europe) focusses on the effectiveness of retention forestry, combining ecological studies on forest biodiversity with social and economic studies of biodiversity conservation across multiple spatial scales. The aim of ConFoBi is to assess whether and how structural retention measures are appropriate for the conservation of forest biodiversity in uneven‐aged and selectively harvested continuous‐cover forests of temperate Europe. The study design is based on a pool of 135 plots (1 ha) distributed along gradients of forest connectivity and structure. The main objectives are (a) to investigate the effects of structural elements and landscape context on multiple taxa, including different trophic and functional groups, to evaluate the effectiveness of retention practices for biodiversity conservation; (b) to analyze how forest biodiversity conservation is perceived and practiced, and what costs and benefits it creates; and (c) to identify how biodiversity conservation can be effectively integrated in multi‐functional forest management. ConFoBi will quantify retention levels required across the landscape, as well as the socio‐economic prerequisites for their implementation by forest owners and managers. ConFoBi's research results will provide an evidence base for integrating biodiversity conservation into forest management in temperate forests.     

Anticarcinogenic antioxidants as inhibitors against intracellular oxidative stress

Oxidative stress has been implicated in the pathogenesis of numerous diseases, including cancer. In the present study, the protective effect of natural antioxidants, such as quercetin and tea polyphenols, on intracellular oxidative stress was studied. Here we report a novel function of quercetin and tea polyphenols, as potential inhibitors of 4-hydroxy-2-nonenal (HNE)-induced intracellular oxidative stress and cytotoxicity. In rat liver epithelial RL34 cells, a potent electrophile HNE dramatically induced the productions of reactive oxygen species (ROS), which correlated well with the reduction in cell viability. We found that quercetin and tea polyphenols, such as epigallocatechin gallate and theaflavins and their gallate esters, significantly inhibited the HNE-induced ROS production and cytotoxicity. In addition, HNE induced a transient decrease in the mitochondrial membrane potential (Δψ), which was also retarded by the antioxidants. These data suggest that the antioxidants, such as quercetin and tea polyphenols, are inhibitors against mitochondrial ROS production.     

云南茶树地方品种农艺性状与品质性状遗传多样性分析

为发掘具有优异农艺性状与品质性状的茶树品种资源,对51份云南茶树地方品种进行农艺和品质性状遗传多样性分析。结果表明,云南茶树地方品种农艺和品质性状存在丰富的遗传变异,农艺性状变异系数平均为25.84%,多样性指数平均为1.94;生化成分变异系数平均为16.53%,多样性指数平均为1.88;茶叶感官审评红茶品质总分达87.5分～94.2分,绿茶品质总分达78.8分～91.5分,茶树品种红、绿茶适制性的多样性指数平均为0.92和0.94;聚类分析将供试材料分为3类：第Ⅰ类品种主要适合制作红茶,第Ⅱ类品种主要适合制作绿茶,第Ⅲ类为生化成分特异性品种。并从中筛选出18份优异品种资源,为今后的生产和育种提供利用。