Results 11 to 20 of about 26,223 (169)

Preparation and antioxidant activity of synthesized vanadyl (Ⅳ) trehalose and vanadyl (Ⅳ) carboxymethyl trehalose [PDF]

open access: yes, 2013
对合成的钒氧海藻糖和钒氧羧甲基海藻糖的结构进行红外光谱分析,并利用ICP-MS测定钒的含量分别为2.9%和3.2%。同时对钒氧海藻糖和钒氧羧甲基海藻糖清除羟基自由基与DPPH自由基的能力进行研究,结果表明,钒氧海藻糖和钒氧羧甲基海藻糖清除DPPH·的能力和清除·OH的能力均比配体的清除能力有显著提高。此外 ...
冯大伟   +4 more
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Life Stage‐Specific Genetic Diversity and Landscape Characteristics Collectively Influence Genetic Recovery in Pometia pinnata Population 生活史阶段特异的遗传多样性与景观特征对番龙眼种群遗传恢复的协同影响

open access: yesIntegrative Conservation, EarlyView.
Pometia pinnata demonstrated life‐stage‐specific genetic responses to landscape features, with asymmetric gene flow patterns and population recovery following historical bottlenecks, revealing complex topographic and demographic influences on forest genetic structure.
Madhuparna Chatterjee   +5 more
wiley   +1 more source

Study on disinfection and sterilization of high algae-laden water with Hydroxyl radicals [PDF]

open access: yes, 2016
消毒灭菌是饮用水处理工艺中的重要组成部分。而地表水富营养化现象日益加剧,导致水源地高藻频发,增加了饮用水常规氯消毒处理工艺的负担,严重威胁城市供水卫生安全。如何平衡饮用水微生物安全性与化学安全性,成为当前高藻饮用水消毒技术研究的重要内容。本文依托国家科技支撑计划项目“高藻水源地供水卫生保障羟基自由基氧化技术研发与示范”(NO.2013BAC06B00),针对厦门市重要水源地九龙江北溪流域水体,通过大气压强电离放电规模制备羟基自由基(•OH),建立了高藻饮用水•OH消毒灭菌处理工艺,
黄孟斌
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Elevation, soil pH and calcium availability shape regional and local scale spatial patterns of PhoD gene abundance in tropical and subtropical forests

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Organic phosphorus mineralization is a critical process in the phosphorus cycle, governing phosphorus bioavailability for plants. The PhoD gene, which encodes the key enzyme alkaline phosphatase, serves as a valuable biomarker for this process.
Sandhya Mishra   +3 more
wiley   +1 more source

The role of appoptosin in regulating oxidative stress and mitochondrial morphology [PDF]

open access: yes, 2015
氧化压力是指细胞或体内氧自由基的含量超出抗氧化物及抗氧化酶类清除能力时对细胞或机体造成的氧化胁迫。氧化压力参与了包括炎症、衰老、心血管疾病、癌症、糖尿病、艾滋病、神经退行性疾病等多种疾病的发病过程。氧化压力通过多个下游信号通路对细胞造成胁迫,如JNK、Foxo等,但其中的具体参与蛋白仍有待于深入阐明。Appoptosin也被称为SLC25A38,是一种定位于线粒体内膜的转运蛋白,负责转入甘氨酸并转出D-氨基乙酰丙酸,进而调节血红素(heme)的合成 ...
张翠林
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Parental care and bird embryonic metabolism: A comparison between uniparentally incubating Silver‐throated Tits and biparentally incubating Black‐throated Tits

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Studies have shown that organisms may adjust metabolic rates in response to thermal variability, highlighting metabolic plasticity as a key adaptive mechanism. Understanding the extent of metabolic plasticity of an organism is key to predicting its adaptation to climate
Qian Hu   +6 more
wiley   +1 more source

自由基捕捉剂结构对γ射线辐照作用下乙烯-醋酸乙烯共聚物稳定性的影响

open access: yesFushe yanjiu yu fushe gongyi xuebao
探究了N,N-二仲丁基对苯二胺(44PD)、特丁基对苯二酚(TBHQ)、二硫化二异丙基黄原酸酯(DIP)三类自由基捕捉剂对γ射线辐照作用下乙烯-醋酸乙烯共聚物(EVA)结构演化与性能变化行为的影响。热重分析(TGA)结果表明,三类自由基捕捉剂可抑制较高吸收剂量下EVA中聚乙烯链段的裂解。凝胶含量及应力松弛测试结果表明,三类自由基捕捉剂均可抑制EVA内部交联结构的构筑,其中,胺类抗氧剂44PD的抑制效果相对不明显,但吸收剂量较高时,含自由基捕捉剂的EVA,其交联结构较为完善,应力松弛速率较低 ...
胡 心芸   +6 more
doaj   +1 more source

Nitrogen deposition does not exacerbate phosphorus limitation of rhizosphere microbes in subalpine forests

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometric imbalance caused by nitrogen (N) deposition typically exacerbates phosphorus (P) limitation in plants. However, it remains unclear whether this effect extends to soil microbes, particularly those in the rhizosphere.
Jipeng Wang   +5 more
wiley   +1 more source

Chiral transition mechanism and water solvation effect of stable configurations of histidine molecules(组氨酸分子几种稳定构型的手性转变机理及水溶剂化效应)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2018
采用密度泛函理论的B3LYP方法、微扰理论的MP2方法和自洽反应场(SCRF)理论的smd模型方法,研究了组氨酸分子3种最稳定构型的手性转变机理及水溶剂化效应.发现标题反应有a、b、c 3条通道,对于构型1和2,a是手性碳上的质子先以氨基为桥迁移,b是羟基异构后手性碳上的质子再以氨基为桥迁移,c是以羧基和氨基联合作桥实现质子迁移.对于构型3,a是质子只以氨基为桥迁移,b是质子顺次以羰基与氨基为桥迁移,c是质子顺次以羧基和氨基为桥迁移.计算表明:构型1和2的主反应通道都是b,决速步自由能垒分别为250 ...
WANGZuocheng(王佐成)   +4 more
doaj   +1 more source

The association between the antioxidant property and ROS system in murine corneal epithelial progenitor cells [PDF]

open access: yes, 2016
目的:活性氧(ROS)是体内产生的一种高活性分子,低浓度可以调节细胞代谢,基因转录和磷酸酶的活性,高浓度则会导致氧化损伤。目前,有关干细胞自身特性的研究越来越受到学者们的重视,但既往文献中关于干细胞对氧化应激反应以及应激条件下细胞内相关酶活性的变化规律却很少报道。本课题聚焦于,在过氧化氢(H2O2)诱导的氧化应激条件下,活性氧生成关键因子NOX4和抗氧化酶核转录因子NRF2在小鼠角膜上皮祖细胞(TKE2)和成熟的小鼠角膜上皮细胞(MCE)中的不同作用及相关机制。 方法:利用小鼠角膜上皮祖细胞(TKE2 ...
周晶
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