Trypanocidal Activity of Marine Natural Products

Marine natural products are a diverse, unique collection of compounds with immense therapeutic potential. This has resulted in these molecules being evaluated for a number of different disease indications including the neglected protozoan diseases, human African trypanosomiasis and Chagas disease, for which very few drugs are currently available. This article will review the marine natural products for which activity against the kinetoplastid parasites; Trypanosoma brucei brucei, T.b. rhodesiense and T. cruzi has been reported. As it is important to know the selectivity of a compound when evaluating its trypanocidal activity, this article will only cover molecules which have simultaneously been tested for cytotoxicity against a mammalian cell line. Compounds have been grouped according to their chemical structure and representative examples from each class were selected for detailed discussion.     

小粒种咖啡的主要成分及功能分析

随着我国咖啡产业的快速发展,针对人们对咖啡的主要成分及功能的认识不足,以小粒种咖啡生豆、咖啡烘焙豆、可溶性物质的主要成分及功能进行分析,并总结对人体的主要功能,有助于咖啡生产者及消费者了解咖啡饮品,同时也为咖啡的进一步开发利用提供参考。     

Dielectric relaxation phenomena in flax fibers composite

In this work, a study of the dynamic dielectric analysis of the unidirectional epoxy composite: flax-fibre-reinforced epoxy (FFRE) was investigated. In this composite, three relaxation processes were identified. The first one is the water dipoles polarization imputed to the presence of polar water molecules in flax fiber. The second relaxation process associated with conductivity occurs as a result of the carriers charges diffusion. As for the third dielectric relaxation associated with the interfacial polarization effect is attributable to the accumulation of charges at the fibers/matrix interface. The analysis of the Maxwell-Wagner-Sillars (MWS) and the water dipoles polarizations using the Havriliak-Negami model revealed the high adhesion of flax fibers in the matrix. This analysis was supported by the thermal properties using a Differential Scanning Calorimety (DSC).     

Evaluating antistatic performance of plasma-treated polyester

Use of low temperature plasma treatment has been attempted in the textile industry and there the has been some success in the dyeing and finishing processes. In this paper, an attempt was made to apply low temperature plasma treatment to improve the antistatic property of polyester fabric. The polyester fabrics were treated under different conditions with low temperature plasma. An orthogonal array testing strategy was employed for obtaining the optimum treatment condition. After low temperature plasma treatment, the polyester fabrics were evaluated with different characterization methods. Under the observation of scanning electron microscope, the surface structure of the polyester fabric treated by low temperature plasma was found to be seriously altered which provided more capacity for polyester to capture moisture and hence increased the static charges dissipation. The relationship between moisture content and half-life decay time for static charges was studied and the results showed that the increase in moisture content would result in shortening of the time for static charges dissipation. Moreover, the antistatic property of the low temperature plasma treated polyester fabric was greatly improved. In addition, the antistatic property of the polyester fabric treated by low temperature plasma was compared with that of the polyester fabric treated with a commercial antistatic finishing agent.     

二项式定理在遗传学问题中的应用

分析大学遗传学教学中有关二项式定理在解决遗传学问题方面的相关内容,将问题分类并解答示范,为加深学生对该内容的理解和掌握,以及教师的课堂教学提供帮助和参考。     

An overview of German cockroach, Blattella germanica, studies conducted in Iran

The control and elimination of German cockroach, the most important worldwide pest species, has been an economic and public health success. Too many studies have been conducted in Iran, whereas these researches was scattered in form of national and international articles that has needed to add up of them in an overview article. With doing of this work the way is smooth to future studies and the strategies of these studies will be distinguished. This article is outlook in direction of above aims. The susceptibility level and insecticide resistance mechanisms of German cockroach to organochlorated, organophosphate, carbamate and pyrethroid insecticide groups have been studied. The new insecticidal compounds include fipronil and avermectins acting at GABA and glutamate receptors in proximity to chloride channels, diacylhydrazines mimicking the action of ecdysone, indoxacarb acting at a novel site in sodium channels and imidacloprid, thiamethoxam and spinosad acting at novel sites on the nicotinic acetylcholine receptor, several promising products acting at new target sites, which are currently not affected by resistance that will be used for pest control specially Blattella germanica. Attentive to resistance of B. germanica to current consuming insecticides and ever-increasing add to intensity of it, the researchers have been considering the susceptibility level of B. germanica and efficiency estimation of them to above-mentioned insecticides for control of this pest. The strategies of future researches are study of the susceptibility level of B. germanica and efficiency estimation of them to above-mentioned insecticides for control of this pest in Iran.     

Marine Indole Alkaloids—Isolation,Structure and Bioactivities

Indole alkaloids are heterocyclic natural products with extensive pharmacological activities. As an important source of lead compounds, many clinical drugs have been derived from natural indole compounds. Marine indole alkaloids, from unique marine environments with high pressure, high salt and low temperature, exhibit structural diversity with various bioactivities, which attracts the attention of drug researchers. This article is a continuation of the previous two comprehensive reviews and covers the literature on marine indole alkaloids published from 2015 to 2021, with 472 new or structure-revised compounds categorized by sources into marine microorganisms, invertebrates, and plant-derived. The structures and bioactivities demonstrated in this article will benefit the synthesis and pharmacological activity study for marine indole alkaloids on their way to clinical drugs.     

THE PROFITABLE USE OF GRASSLAND IN MILK PRODUCTION

The most profitable use of grass in feeding a dairy herd is considered. Provided that the quality of the grass and grass products is sufficiently high for it to be used for part of the production ration, it is possible either to maintain a larger herd by buying concentrates, or to keep a smaller herd, feed less concentrates and use part of the grass for production. The potential herd size will depend both on the level of concentrate feeding and on the milk yield of the herd.
When account is taken of the extra costs involved with larger herds (labour, capital charges and some variable costs) the optimum system depends on the level of milk yield. For herds yielding below 900 gallons average, the most profitable system is that which obtains the maximum production from grass. With herds of over 1000 gallons average it is more profitable to use concentrates for the production ration and to keep the maximum number of cows.     

大豆加工利用研究进展

对大豆加工国内外发展概况、大豆营养价值、功能因子、以及大豆功能食品加工工艺几个方面作了综述，进一步认识到大豆的加工利用价值，为大豆的进一步开发提供参考。     

R语言及在农业试验数据分析中的基本应用（一）

R语言已是科学研究中最流行的计算语言,但在我国农业试验数据分析的应用还不多。我们介绍R语言以及在农业试验数据分析中的基本应用。作为其中的第一篇,本文重点介绍R软件的下载、安装以及起步使用的一些基本知识,期望我国农业科技工作者对R语言有初步了解并尝试利用R语言分析试验数据。     

辣椒红色素制取和应用研究概述

辣椒红色素作为优质的天然色素,具有广阔的国内外市场。我国既是辣椒红色素潜在生产国,又是其潜在的巨大市场。依据国内近２０年来有关辣椒红色素的研究资料,概述了辣椒红色素特性、提取工艺、除辣技术、提高产出率和稳定性以及应用方面的研究成果和信息,期望能对辣椒红色素的研究、开发和产业化有所裨益。     

山地有机循环茶园体系优化构建与生产技术对策研究

茶业是乡村振兴与农民增收的重要产业.目前茶业发展呈现良好的态势,但依然存在4个突出制约生产种植发展的因素:优良品种选育与更新换代;茶园水土流失与生态恢复;土壤酸化与有效改良技术;多样功能发挥与"四生茶园"(生产-生活-生态-生命耦合联动茶园).实践表明,有机循环茶园的优化构建与有效运作,有助于解决制约茶叶生产的关键问题,进而促进茶产业的高质量发展.有机循环茶园是现阶段乡村绿色发展的新动态,也是常规有机茶业的转型升级版.本文阐述了有机循环茶园发展内涵、体系优化构建、基本技术要求,并提出了促进山区乡村有机循环茶园高质量发展对策的若干思考.     

植物镁素生理功能及镁素营养诊断和施用

随着土壤缺镁状况日益突出,缺镁对植物的正常生理功能和生长发育的影响越来越明显,因此镁肥的施用越来越受到重视。综述了植物镁素的生理功能,主要包括光合生理功能、酶活化功能、植物镁素对植物活性氧代谢和基因表达的影响,以及植物镁素营养诊断与镁肥的施用,为植物镁素营养的深入研究提供理论依据和参考。     

低热量功能性油脂——结构脂质的研究与开发前景

从功能性油脂分类的角度,对多不饱和脂肪酸、磷脂和新型功能性油脂——结构脂质的发展史及国内外研究概况进行了介绍,并对现阶段广泛研究的新型功能性油脂——结构脂质的合成方法做了介绍。揭示了以大豆为原料,通过酶法催化工艺,开发一种新型低热量功能性油脂对于改善人民健康水平的重要意义。     

Making Rice a Perfect Food

Abstract

Despite a significant increase in food production during the last century, world production will need to be doubled or tripled by the year 2050 to meet the needs of an expected 10 billion global population. Fortunately, a second revolution in agriculture appears to be taking place from advances in biotechnology. Worldwide in 1999, about 40 million hectares of transgenic plants were grown, and this area is expected to increase significantly for years to come. Rice (Oryza sauva L.) is the staple food of the majority of 3.5 billion people in Asia. Increases in population in the rice growing regions of Asia will require 70% more rice in 2025 than is consumed today. In addition, rice, in its milled form, is poor in essential amino acids and a range of vitamins and micronutri-ents, which creates malnutrition. With the increasing number of genes discovered in plants and other organisms, transgenic research is being utilized to improve agronomic traits of rice, such as resistance to biotic and abiotic stress, and to increase photosynthetic efficiency which collectively increase yield. Research is also moving toward improvement of grain quality traits, including amino acids, micronutrients, and vitamins. Genome sequencing and the techniques for rice transformation have been developed. Thus, collaborative efforts in genomics, transformation, and molecular breeding of rice are expected to lead to a significant contribution to global food security. In this article, we review the current status of genetic improvement of rice. Improved methods for transgene expression in rice and potential modifications that will significantly improve yield and grain quality of rice are also discussed.     

Protein adsorption on and swelling of polyelectrolyte brushes: A simultaneous ellipsometry-quartz crystal microbalance study

With a coupled spectroscopic ellipsometry-quartz crystal microbalance with dissipation (QCM-D) experimental setup, quantitative information can be obtained about the amount of buffer components (water molecules and ions) coupled to a poly(acrylic acid) (PAA) brush surface in swelling and protein adsorption processes. PAA Guiselin brushes with more than one anchoring point per single polymer chain were prepared. For the swollen brushes a high amount of buffer was found to be coupled to the brush-solution interface in addition to the content of buffer inside the brush layer. Upon adsorption of bovine serum albumin the further incorporation of buffer molecules into the protein-brush layer was monitored at overall electrostatic attractive conditions [below the protein isolectric poimt (IEP)] and electrostatic repulsive conditions (above the protein IEP), and the shear viscosity of the combined polymer-protein layer was evaluated from QCM-D data. For adsorption at the "wrong side" of the IEP an incorporation of excess buffer molecules was observed, indicating an adjustment of charges in the combined polymer-protein layer. Desorption of protein at pH 7.6 led to a very high stretching of the polymer-protein layer with additional incorporation of high amounts of buffer, reflecting the increase of negative charges on the protein molecules at this elevated pH.     

Modeling the dependence of the crop calendar for rain-fed rice on precipitation in Northeast Thailand

Rain-fed lowlands are major agricultural ecosystems used for rice production in Northeast Thailand. Developing a tool to assess the effects of variable water conditions on the regional scale yield is also important to predict the effects of climate change on food supply. To estimate regional yields, we need a simple but accurate measure of the crop calendar (i.e., the distribution of planting dates), which has a strong influence on grain yield. In this article, we modeled the dependence of the crop calendar on rainfall patterns based on a survey of the region’s farmers as a part of an effort to provide a stronger basis for regional yield estimates. Our survey, conducted in 11 provinces for 2 years, confirmed the existence of large windows for sowing and transplanting versus narrow windows for heading and harvesting for rain-fed lowland rice culture in all the provinces. Variable water, soil, and toposequential conditions in the paddy fields were responsible for the large sowing and transplanting windows, whereas the use of photoperiod-sensitive varieties explained the narrow windows for heading and harvesting. The crop calendar was well expressed as a function of cumulative precipitation from June onward. When the crop calendar model was combined with a simple phenology-based model that uses growing degree-days adjusted by a day-length factor, we could estimate the rice crop calendar under rain-fed lowland conditions with acceptable accuracy. The model described in this article will be combined with a crop growth model to improve regional yield estimates for rain-fed lowland rice.     

豆浆稳定性工艺优化的研究

豆浆作为营养健康的食品受广大人群的欢迎,但是放置过久后会出现分层现象,影响豆浆的质量和销售.分别对影响稳定性高低的均质压力、添加乳化剂、稳定剂和低价盐进行单闪素试验,并用正交设计实验来确定最佳工艺提高稳定性.结果表明:当均质条件是15 Mpa,CMCNa添加量为0.05%,单甘酯添加量为0.1%,NaCl添加量为0.025%时,复配后的豆浆稳定系数可以达到0.784,可以在4℃放置1个月不分层.     

蒸青绿茶在中日的发展历史及现状

由蒸青绿茶在中国的发展演变史及在日本的传播发展史出发,概述了蒸青绿茶的加工制作、引种栽培和贸易发展史,以及当前的加工技术与蒸青绿茶在各领域中的应用情况,由此对蒸青绿茶的发展进行了展望并提出自己的一些见解。     

大豆细菌性病害的识别与综合防治

大豆细菌性病害是大豆生产上常见的病害.如果气候条件适宜病菌生长、田间管理不当,则对大豆生产造成一定影响.基于生产实践及研究,介绍三种大豆细菌性病害的症状识别、发病规律及其综合防治措施.