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771.
MARCELO P. HERNANDO IRENE R. SCHLOSS FLORENCIA DE LA ROSA MARLEEN DE TROCH 《Biocell》2022,46(3):607-621
Under the present changing climate conditions and the observed temperature increase, it is of high importance to understand its effects on aquatic microbial life, and organisms’ adaptations at the biochemical level. To adjust to temperature or salinity stress and avoid cell damage, organisms alter their degree of fatty acids (FAs) saturation. Thus, temperature is expected to have strong effects on both the quantity and quality of FAs in aquatic microorganisms. Here we review some recent findings about FAs sensitivity to climate change in contrasting environments. Overall, heat waves may induce changes in the relative abundance of polyunsaturated FAs (PUFA). However, the impact of the exposure to warming waters is different in temperate and polar environments. In cold marine waters, high concentration of omega-3 (ω3) FAs such as eicosapentaenoic acid (EPA) is promoted due to the activation of the desaturase enzyme. In this way, cells have enough energy to produce or activate antioxidant protection mechanisms and avoid oxidative stress due to heat waves. Contrastingly, under high irradiance and heat wave conditions in temperate environments, photosystems’ protection is achieved by decreasing EPA concentration due to desaturase sensitivity. Essential FAs are transferred in aquatic food webs. Therefore, any alteration in the production of essential FAs by phytoplankton (the main source of ω3) due to climate warming can be transferred to higher trophic levels, with cascading effects for the entire aquatic ecosystem. 相似文献
772.
针对工程实际问题,以反向、变速、同步旋转的振动电机作为振动筛的激振器,通过反向同步控制电路、变频调速控制电路和准确的安装位置,可实现单轴式、双轴式和多轴式线性非共振激振器的功能。以振动电机产生的能量、无传动装置的方式直接驱动工作机体做设计要求的抛掷运动。阐述了振动电机同步振动筛的基本构成、设计原理和激振力的调整确定方式,分析计算了振动系统的振动强度、频率、振幅和输送速度等主要工作参数。与传统激振器振动筛相比,这种新型振动筛的供料输出能力和筛分效率有很大提高。 相似文献
773.
繁缕挥发油的GC—MS分析 总被引：2，自引：0，他引：2
采用水蒸气蒸馏法提取野生繁缕全草挥发油,并用气相色谱-质谱（GC—MS）联用技术对挥发油成分进行分析,用峰面积归一法测定其相对含量。共鉴定出49种成分,占总油量的69．32％。分析结果表明,脂肪醇和烷烃及其衍生物是繁缕挥发油的主要成分,占总挥发油的50．47％;已鉴定成分中的脂肪醇占总挥发油的25．48％,而其中不饱和脂肪醇占总脂肪醇的78．49％。此外芳香族化合物占13．27％,还有少量酯和蒽的衍生物等。 相似文献
774.
关键蛋白质对于细胞生活是不可缺少的,识别关键蛋白质可以帮助了解细胞生活的最小需求,同时对药物设计也有非常大的作用。随着高通量技术的发展,人们可得到越来越多的蛋白质-蛋白质相互作用(PPI)的数据,这就使得可以在网络层次上来研究关键蛋白质。目前,学术界已经提出了一系列的计算方法来识别关键蛋白质,但这些方法并没有完全解决蛋白质相互作用数据的假阳性问题。除此之外,现有方法一般只考虑了网络的拓扑结构,对于生物信息的考虑,目前还是比较欠缺的。蛋白质对于人类细胞的生命活动不仅仅与网络拓扑结构有关,还和蛋白质在网络上的生物信息相关。因此,针对以上问题,提出了一种高效的预测关键蛋白质的新方法EPP(Essential Proteins Predict),该方法通过计算蛋白质在PPI网络中的重要性来进行预测,蛋白质的重要性越高,成为关键蛋白质的可能性就越大。取重要性排名前P%的蛋白质作为关键蛋白质,在进行蛋白质重要性的计算时,综合考虑语义相似度及可信度因素,以综合考虑网络的拓扑结构与蛋白质本身的生物信息。实验结果表明,与其他传统方法相比,提出的新方法复杂度较低,且能够识别出更多的关键蛋白质,并且其统计指标也高于其他的方法。 相似文献
775.
Secret image sharing is a method to decompose a secret image into shadow images (shadows) so that only qualified subset of shadows can be used to reconstruct the secret image. Usually all shadows have the same importance. Recently, an essential SIS (ESIS) scheme with different importance of shadows was proposed. All shadows are divided into two group: essential shadows and non-essential shadows. In reconstruction, the involved shadows should contain at least a required number of shadows, including at least a required number of essential shadows. However, there are two problems in previous ESIS scheme: unequal size of shadows and concatenation of sub-shadow images. These two problems may lead to security vulnerability and complicate the reconstruction. In this paper, we propose a novel ESIS scheme based on derivative polynomial and Birkhoff interpolation. A single shadow with the same-size is generated for each essential and non-essential participant. The experimental results demonstrate that our scheme can avoid above two problems effectively. 相似文献
776.
Soumaya Bourgou Sonia Tammar Nidhal Salem Khawla Mkadmini Kamel Msaada 《International Journal of Food Properties》2016,19(3):549-563
This study characterized the phenolic, aroma compositions, and antioxidant capacities of four Artemisia herba alba accessions collected from north and center regions in Tunisia in order to select valuable origin with optimal bioactive compounds production. The total polyphenol and flavonoid contents varied between accessions with maxima contents observed in center regions. Kaempherol, apigenin, naringenin, p-coumaric, trans-cinnamic, and caffeic acids were the most abundant compounds with percentage varying depending on the considered accession. Significant changes on essential oil yields (0.4–1.2%) were found between accessions and three different oil chemotypes were distinguished: camphor, fenchol/α-thujone, and α-thujone/camphor. Cluster analysis of volatile and phenolic compositions grouped the accessions on different groups. Antioxidant activities of extracts were found to be higher than essential oils for the four provenances. The results suggested that the center regions have high potential for selecting varieties rich on essential oil, antioxidant phenolic acids, and flavonoids. 相似文献
777.
This research aimed to find plant essential oils with a strong fumigant-specific toxicity effects against Callosobruchus maculatus and Bruchus rufimanus, but which have lower side effects on their parasitoids wasps Dinarmus basalis and Triaspis luteipes. For that, the essential oils of Artemisia herba-alba, A. campestris and A. absinthium were investigated for their chemical composition using GC and GC–MS analysis and were used in a manner that combined exposure to their essential oils with parasitoids releases. Essential oils were assessed for their direct fumigant toxicity against both bruchid beetles and for their residual effects on parasitism rates and pests offspring control. The introduction of D. basalis and T. luteipes adults were done 6 days after the oil application.The results showed that A. campestris essential oil can be considered compatible with the natural enemies for controlling stored food legume beetles. When the parasitoids D. basalis and T. luteipes were released six days after the application of A. campestris oil, the parasitism rates reached 13.6% and 80.3% for C. maculatus and B. rufimanus respectively. Moreover, 26.6% of C. maculatus offspring have emerged, while for B. rufimanus a complete lack of offspring was recorded. Adults of D. basalis were more susceptible to oils vapours than adults of T. luteipes.The release of parasitoids could better be combined with essential oils of A. campestris, as this oil had more pronounced effects on the beetles than on their parasitoids, in particular for the case of B. rufimanus and T. luteipes. 相似文献
778.
779.
地被植物在园林中的应用及研究现状 总被引：126，自引：12，他引：126
探讨了地被植物的内涵，调查了浙江省园林中常见的多年生草本地被植物，并提出了一些未在园林中应用的观赏价值较高的野生及彩叶地被植物，初步探讨了地被植物的研究方向。 相似文献
780.
乡土建筑的内涵与设计借鉴 总被引：1，自引：0，他引：1
本文在界定乡土建筑内涵的基础上,指出可以从乡土建筑的群体布局,平面布置,建筑细部中吸取有益成分,进行现代建筑设计. 相似文献