PCR-SSCP技术在微生物群落多态性分析中的应用进展

PCR-SSCP技术是新近发展起来的一种分子生物学分析技术,因具有快速、简便、灵 敏和适于大样本筛查的特点,能有效检出碱基置换、缺失、插入等基因变异,因而有广泛和 潜在的应用价值.该文较系统地介绍了PCR-SSCP方法的发展过程、技术优势及其在环境生态 、食品微生物等领域中微生物群落多态性检测的应用进展,并对其发展前景作了展望.     

食品微生物快速检测技术研究

在人们对食品安全重视程度日益加深的今天,要想保证食品卫生质量,就必须借助相应的检测手段,对食品的微生物情况进行监测。但是传统的检测手段存在众多的缺陷,不足以应付日益上涨的食品安全需求,所以一系列新型的微生物快速检测技术应运而生。目前用于食品微生物快速检测的技术主要包括免疫学技术、代谢学技术和分子生物学技术三个方面,这些检测技术以其快速、简便、高效等优点极大程度上保障了食品安全。本文主要对目前的食品微生物快速检测技术进行详细分析。     

分子生物学技术在生物修复中的应用研究进展

随着分子生物学技术如分子杂交、PCR、电泳技术等的发展,微生物学研究领域发生了深刻的变革,灵敏的检测和精确的细菌鉴定成为可能.微生物分子生态学作为分子生物学与微生物生态学交叉而形成的学科,在生物修复方面得到广泛应用.从分子生物学实验技术角度综述了各种微生物分子生物学技术在生物修复中的应用研究情况.     

分子生物学方法在食品微生物检测中的应用研究

众所周知,近年来的食品安全问题层出不穷,既带来了恶劣的社会影响,更对消费者的身心健康构成了威胁,故在此背景下,食品安全问题备受关注,利用分子生物学方法检测食品微生物随之发展。对此,本文就分子生物学方法在食品微生物检测中的应用作了研究,希望对解决食品安全问题有所启示。     

食品微生物检验技术研究进展

在食品微生物检验工作中,微生物检验分析技术以传统方法为主。传统方法存在检验操作繁琐、检验周期长、检验工作效率不高等问题。而近年来,微生物检验分析技术已经有了突飞猛进的发展。各种核酸扩增技术、高通量并行检测技术、DNA指纹分析技术、飞行时间质谱分析技术等新技术的发展层出不穷。这些技术对于推动微生物检验技术向着更加简便、快速、灵敏、高效和准确的方向发展具有非常重要的意义。     

分子生物学技术对肠道菌群检测分析的研究现状

分子生物学检测技术被应用于检测各种微生物存在近几年已有长足的研究进展,这为研究肠道菌群多样性及其细微变化提供了更加准确可靠、重复性好和更加省时省力的检测技术。现将近5年有关各种分子生物学技术检测分析肠道菌群的研究现状作文献综述。     

基因芯片技术在食品检测中的应用

基因芯片技术是鉴别微生物和转基因成分最有效的手段之一,为全面、快速、准确地进行食品安全检测提供了一个崭新的平台。本文阐明了近年来基因芯片技术在食品微生物、食品转基因成分等检测研究中的基本原理、方法和应用,并综述了基因芯片技术在食品检测中存在的问题、解决方法与发展方向。     

浅析分子生物学技术在临床常见病原微生物快速检测中的应用

目的:分析与探讨分子生物学技术在常见病原微生物的快速检测中的应用与作用。方法:将2014年10月至2015年10月期间,我院在临床常见病原微生物的快速检测中所应用的分子生物学技术作为本篇论文的分析对象,回顾性分析相关资料。结果:我院所应用的分子生物学技术主要有三种,即聚合酶链反应(PCR)技术、基因(DNA)芯片技术以及生物传感器技术,上述三种新兴的分子生物学技术都具有自身独特的优点,均可以为临床常见病原微生物的快速检测提供一定的便利条件。结论:在临床常见病原微生物的快速检测中,分子生物学技术发挥着非常大的作用,合理、有效地应用分子生物学技术,具有重要的意义。     

分子生物学技术在环境微生物监测中的应用

随着环境生物学的发展,对环境中复杂的混合微生物群落进行及时监测和准确鉴定变得越来越重要。但是传统的研究方法因为检测速度慢、准确性差等缺点,在某种程度上已经不适应于这方面的研究;而以ＰＣＲ（ｐｏｌｙｍｅｒａｓｅ ｃｈａｉｎ ｒｅａｃｔｉｏｎ）技术为主的一些分子生物学技术因具有快速、灵敏的特点,正被越来越多的人所采用。目前,这些分子生物学技术已能在ｒＤＮＡ测序和有关结构基因分析的基础上监测和定量复杂的混合微生物群落中的一些特殊的微生物,而且其中许多技术都是在ＰＣＲ扩增的基础上来检测混合微生物群落中原本…     

分子生物学方法在环境微生物生态学中的应用研究进展

随着分子生物学方法的不断发展和改进,微生物在生态系统中的作用被更好的挖掘出来。目前快速发展的先进的分子生物学技术,已经开始应用于分析环境微生物的多样性、微生物的生物地理学及微生物对气候变化的响应等。一般环境微生物的研究目标主要有3个,即确定微生物的种类和多样性、微生物的功能或潜在作用及在特定时间点活跃的微生物等。然而,现有微生物的研究方法复杂多样,容易给研究者在方法的选择上带来困惑。将从微生物的多样性和功能研究两个方面介绍和分析相应的分子生物学方法,尤其是近年来快速发展的高通量测序、宏组学和单细胞水平研究方法(如纳米二次离子质谱与荧光原位杂交相结合的方法)等新技术及其应用情况,以期为研究者选择合适的研究方法进行环境微生物的研究提供依据。     

Potential and attainable food production and food security in different regions

Growing prosperity in the South is accompanied by human diets that will claim more natural resources per capita. This reality, combined with growing populations, may raise the global demand for food crops two- to four-fold within two generations. Considering the large volume of natural resources and potential crop yields, it seems that this demand can be met smoothly. However, this is a fallacy for the following reasons. (i) Geographic regions differ widely in their potential food security: policy choices for agricultural use of natural resources are limited in Asia. For example, to ensure national self-sufficiency and food security, most of the suitable land (China) and nearly all of the surface water (India) are needed. Degradation restricts options further. (ii) The attainable level of agricultural production depends also on socio-economic conditions. Extensive poverty keeps the attainable food production too low to achieve food security, even when the yield gap is wide, as in Africa. (iii) Bio-energy, non-food crops and nature compete with food crops for natural resources. Global and regional food security are attainable, but only with major efforts. Strategies to achieve alternative aims will be discussed. <br>     

Effects of food diversity on diatom selection by harpacticoid copepods

The diversity of species assemblages which occupy a basal position in the trophic pyramid (typically unicellular algae in aquatic environments) is known to influence the interaction with organisms of higher trophic levels. A laboratory feeding experiment was conducted with cultures of three benthic diatom species (Navicula phyllepta, Grammatophora marina and Cylindrotheca closterium) as primary producers and three harpacticoid copepod species (Harpacticus obscurus, Paramphiascella fulvofasciata and Tigriopus brevicornis) as grazers to evaluate the effects of food diversity (and concomitant food availability) on grazing selectivity. This kind of selectivity experiments is singular for benthic harpacticoid copepods as so far, information on food selection of harpacticoids is scarce.Uptake of a unispecific food source by a single copepod species decreased as food diversity (and concomitant overall food concentration) increased. All three consumers reacted similarly to changing food diversity, but exhibited strong species-specific responses to food identity i.e. which diatom was added was crucial. Irrespective of level of food diversity, H. obscurus took up high amounts of G. marina, whereas both P. fulvofasciata and T. brevicornis preferred C. closterium when given the choice between different diatoms. As for zooplanktonic taxa, this experiment showed that in lower benthic marine food webs both prey organisms (primary producers) and grazers play a very specific role. Diversity of food and its identity are of critical importance at the base of the trophic pyramid, influencing trophic transfer from primary producers over grazers to higher trophic levels.     

Calidad de la alimentación de adultos mayores de Santiago de Chile

IntroductionWith the increase in the elderly population of Chile, it is very important to evaluate the quality of food of this age group using simple and quick tools.ObjectiveTo compare the food quality of the elderly, according to gender and age.Material and methodsA cross sectional study was conducted on 458 elderly subjects ≥ 60 years-old of Santiago de Chile. Each one of them were interviewed in their home using the Food Quality Survey for Elderly (FQSE). The objective of this survey is to measure the quality of the food and preparations considered healthy and/or unhealthy for elderly. Weight and height, was obtained from the control document of the elderly.ResultsMen consume a higher number of unhealthy foods compared to women (P = .01). On comparing ages, those over 80 years-old consumed less unhealthy foods (P = .01). The elderly obese showed a lower score in unhealthy eating habits and total intake score.ConclusionWomen eat healthier compared to men, and better eating habits are observed at an older age, especially in men. Finally, on comparing nutritional status, the elderly obese are those who eat in the most inadequate form.     

北草蜥个体发育过程中头部两性异形及食性的变化

报道了北草蜥（Ｔａｋｙｄｒｏｍｕｓ ｓｅｐｔｅｎｔｒｉｏｎａｌｉｓ）的头部大小两性异形和食性在个体发育过程中的变化,讨论该种两性异形的进化选择压力。北草晰成体体长无显著的两性差异,两性异形主要表现为雄性个体有较大的头部（头长和头宽）。头部大小的两性异形在孵出幼体就已经存在。头部随ＳＶＬ的增长速率在个体发育的不同联合体是不同的,并随个体发育的进行变得更为显著。协方差分析显示,成年雌体特定ＳＶＬ的头部     

Patterns of feeding and food pellet retrieval by Norway rats during food deprivation

This study examined whether, for Norway rats suffering a body weight deficit of sufficient magnitude, food hoarding is prepotent over feeding. Rats food-deprived to 85% ad lib weight were videotaped during hoarding sessions that lasted until they ceased to hoard or eat to obtain complete records of retrieval and feeding. During the early minutes of a trial, feeding was the predominant activity, and food pellet retrieval occurred singly or in short bouts. This gave way over time to diminished eating and extended bouts of retrieval (hoarding). Closer analysis suggested that retrieval and feeding were aroused together and at the beginning of such arousal retrieval was momentarily prepotent over feeding. But once retrieval had occurred, there was a shift in favor of feeding. After the rat had consumed a sufficient amount of food, feeding was no longer aroused to the same degree, so bouts of retrieval occurred without feeding. Electronic Publication     

Measuring fruit patch size for three sympatric indonesian primate species

Food availability is one of the basic factors affecting primate density and socioecology, but food availability is difficult to assess. Two different ways to obtain accurate estimates of food availability have been proposed: using phenology data or using the behaviour of animals. Phenology data can be refined by only including trees that are large enough to be used; including (potential) tree species in which by the concerned primate species forage; or including (fruiting) trees of these species that actually produce fruit. Alternatively, the sizes of the actually visited trees (foraging trees) give an estimate of fruit availability. These measures are compared for three sympatric primate species at the Ketambe Research Station, Sumatra, Indonesia: the Thomas langur, the long-tailed macaque and the orangutan. The sizes of fruiting trees and the foraging trees are larger than the potential trees. The sizes of the potential trees and of the fruiting trees are similar for the three primate species. This, however, is not reflected in the use of trees: the langurs forage on average in trees of similar size to those producing fruit, whereas the macaques and orangutans forage in trees larger than those producing fruit. The use of trees does not necessitate a different cut off point of included dbhs for the three compared primate species. The use of trees of different sizes, however, may be regulated by food competition. This indicates that sympatric primates make different foraging decisions and that behavioural measures of food availability will be less reliable.     

Ghrelin and food reward: the story of potential underlying substrates

The incidence of obesity is increasing at an alarming rate and this worldwide epidemic represents a significant decrease in life span and quality of life of a large part of the affected population. Therefore an understanding of mechanisms underlying food overconsumption and obesity development is urgent and essential to find potential treatments. Research investigating mechanisms underlying obesity and the control of food intake has recently experienced a major shift in focus, from the brain's hypothalamus to additional important neural circuits controlling emotion, cognition and motivated behavior. Among them, the mesolimbic system, and the changes in reward and motivated behavior for food, emerge as new promising treatment targets. Furthermore, there is also growing appreciation of the impact of peripheral hormones that signal nutrition status to the mesolimbic areas, and especially the only known circulating orexigenic hormone, ghrelin. This review article provides a synthesis of recent evidence concerning the impact of manipulation of ghrelin and its receptor on models of food reward/food motivation behavior and the mesolimbic circuitry. Particular attention is given to the potential neurocircuitry and neurotransmitter systems downstream of ghrelin's effects on food reward.     

Food packaging’s materials: A food safety perspective

Food packaging serves purposes of food product safety and easy handling and transport by preventing chemical contamination and enhancing shelf life, which provides convenience for consumers. Various types of materials, including plastics, glass, metals, and papers and their composites, have been used for food packaging. However, owing to consumers’ increased health awareness, the significance of transferring harmful materials from packaging materials into foods is of greater concern. This review highlights the interactions of food with packaging materials and elaborates the mechanism, types, and contributing factors of migration of chemical substances from the packaging to foods. Also, various types of chemical migrants from different packaging materials with their possible impacts on food safety and human health are discussed. We conclude with a future outlook based on legislative considerations and ongoing technical contributions to optimization of food–package interactions.     

Intrauterine sensitization of ovalbumin in the third trimester increases the risk of food allergy in progeny

Intrauterine sensitization caused by food allergens plays an important role in the food allergy development in progeny. The aim of our study was to determine the critical period of intrauterine sensitization during pregnancy. Female mice were exposed to ovalbumin (OVA) during different trimesters of pregnancy. Lymphocytes from their offspring were isolated and cultured, and proliferation was evaluated by CCK-8 assay. The levels of IFN-γ and IL-4 in serum were measured using ELISA. In addition, the expressions of IFN-γ and IL-4 mRNAs and proteins were detected by real-time PCR and western blot. The mice were divided into the first trimester pregnancy (FTP1 and FTP2) group, the second trimester pregnancy (STP1 and STP2) group, and the third trimester pregnancy (TTP1 and TTP2) group based on the stages of pregnancy in which their mothers were exposed to OVA and their ages. The OVA-specific lymphocyte proliferation of the TTP1 group was statistically significantly greater that in the FTP1 and STP1 groups. The serum level of IFN-γ in the TTP1 group was significantly decreased, and the serum level of IL-4 in the TTP1 group was significantly increased compared with the levels in the FTP1 and STP1 groups. The mRNA and protein expression levels of IFN-γ in the TTP1 group were significantly decreased and the mRNA and protein expression levels of IL-4 in this group were significantly increased compared with the levels in the FTP1 and STP1 groups. Our results suggest that OVA-induced intrauterine sensitization in the third trimester may increase the risk of food allergy after birth.