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191.
Andrea Vega Ninoska Delgado Michael Handford 《International journal of molecular sciences》2022,23(10)
Several metals belong to a group of non-biodegradable inorganic constituents that, at low concentrations, play fundamental roles as essential micronutrients for the growth and development of plants. However, in high concentrations they can have toxic and/or mutagenic effects, which can be counteracted by natural chemical compounds called chelators. Chelators have a diversity of chemical structures; many are organic acids, including carboxylic acids and cyclic phenolic acids. The exogenous application of such compounds is a non-genetic approach, which is proving to be a successful strategy to reduce damage caused by heavy metal toxicity. In this review, we will present the latest literature on the exogenous addition of both carboxylic acids, including the Kreb’s Cycle intermediates citric and malic acid, as well as oxalic acid, lipoic acid, and phenolic acids (gallic and caffeic acid). The use of two non-traditional organic acids, the phytohormones jasmonic and salicylic acids, is also discussed. We place particular emphasis on physiological and molecular responses, and their impact in increasing heavy metal tolerance, especially in crop species. 相似文献
192.
193.
过渡金属氧化物对PVC抑烟机理的ESCA研究 总被引:4,自引:0,他引:4
用ESCA技术对PVC/V2O5,PVC/MoO3,PVC/ZnO和PVC/Fe2O3体系经过210℃/3h恒温热分解后的主体骨架和过渡金属氧化物的结构演变进行了系统研究,结果表明。加入过渡金属氧化物的体系,主体骨架中有第三种结构形式的碳出现;过渡金属氧化物在反应过程中的结构变化有两种不同的形式,ZnO和Fe2O3转化为ZnCl2和FeCl3,而V2O5和MoO3则保持原结构形式不变。V2O5,MOO3。ZnO和Fe2O3对PVC的阻燃抑烟遵循两类不同的机理。 相似文献
194.
The volatilization behavior of Cu, Pb, Sn, Sb, Ni, Zn, Mn, Co, Cr, Cd during pyrolysis of waste printed circuit boards was investigated in a bench-scale fixed-bed pyrolysis system. It was found that volatility of heavy metals increases with operating temperature elevating, and bromine and vacuum have an obvious promoting effect on volatility of most of heavy metals. Over 99% weight of Cu and Ni are still remained in solid residue after pyrolysis, about 20% weight of Sb, Zn and Cd are transfered into liquid and gas during a pyrolysis process at 600 ℃, volatilization fractions of Pb, Sn, Mn, Co, Cr are less than 10% at the same conditions. The contents of heavy metals in liquid and gas products depend on not only volatility of metals, but also their initial contents in printed circuit boards, pyrolysis liquid and gas are primarily contaminated by Cu, Pb, Sn, Sb and Zn, their contents in liquid vary from 10^2 to 10^3 pg/mL, Mn, Co, Cr, Cd were detected only at very low level, less than 10 μg/mL. 相似文献
195.
eljka Ve
eri-Haler Nika Kojc Karmen Wechtersbach Martina Pere Andreja Erman 《International journal of molecular sciences》2022,23(15)
Therapy with mesenchymal stem cells (MSCs) is promising in many diseases. Evaluation of their efficacy depends on adequate follow-up of MSCs after transplantation. Several studies have shown that MSCs can be labeled and subsequently visualized with magnetic nanoparticles (NPs). We investigated the homing of MSCs labeled with magnetic cobalt ferrite NPs in experimentally induced acute kidney injury in mice. To explore the homing of MSCs after systemic infusion into mice, we developed a pre-infusion strategy for optimal tracing and identification of MSCs with polyacrylic acid-coated cobalt ferrite (CoFe2O4) NPs by light and transmission electron microscopy (TEM) in various organs of mice with cisplatin-induced acute kidney injury and control mice. By correlative microscopy, we detected MSCs labeled with NPs in the lungs, spleen, kidney, and intestine of cisplatin-treated mice and in the lungs and spleen of control mice. Our results confirm that labeling MSCs with metal NPs did not affect the ultrastructure of MSCs and their ability to settle in various organs. This study demonstrates the usefulness of cobalt ferrite NPs in ex vivo visualization of MSCs and offers correlative microscopy as a useful method in routine histopathology laboratories for tracing MSCs in paraffin-embedded tissue. 相似文献
196.
Fe2O3由于成本低廉,储量丰富和理论比容量高(1007 mA hg^-1)等特点,在锂离子电池负极材料的应用中极具发展前景.然而一些问题仍然存在,如:充放电过程中比容量的迅速衰减,不可逆的体积膨胀以及较短的循环寿命等.这些问题严重制约了Fe2O3在锂离子电池中的实际应用.为了突破这些局限,本文以金属-有机骨架(MOF... 相似文献
197.
198.
199.
B. KhadroAuthor Vitae A. SikoraAuthor VitaeA.-S. LoirAuthor Vitae A. ErrachidAuthor VitaeF. GarrelieAuthor Vitae C. DonnetAuthor VitaeN. Jaffrezic-RenaultAuthor Vitae 《Sensors and actuators. B, Chemical》2011,155(1):120-125
Pure diamond-like carbon (DLC) thin films and boron-doped DLC thin films have been deposited on silicon substrates using femtosecond pulsed laser. The amorphous carbon materials (DLC), have been deposited at room temperature by ablating graphite targets with an amplified Ti:sapphire laser of 800 nm wavelength and a pulse duration of 150 fs in high vacuum conditions. Doping with boron has been performed by ablating alternatively graphite and boron targets.In this study, the DLC films were used as working electrodes for the electrochemical detection of trace heavy metals namely, Cd2+, Pb2+, Ni2+ and Hg2+, by using square wave anodic stripping voltammetry (SWASV) technique. Four metals were detected at −1.3 V deposition potential, and 90 s deposition time. The DLC films have been characterized by multiwavelength Raman spectrometry and high resolution scanning electron microscopy. The effect of the boron doping on the electrochemical behavior has been shown. The a-C:B 8%/Si3N4 electrode gives the more sensitive detection. The four metals are detected simultaneously with a detection limit of 1 μg/L or 2 μg/L and a dynamic range from 1 or 2 to 25 μg/L for every metal, as presented in third table of this article. The different sensitivities obtained are 6.2, 20.0, 1.2 and 6.6 μA/ppb or μA μg−1 L for Cd2+, Pb2+, Ni2+ and Hg2+, respectively. 相似文献
200.
针对岩土锚固系统中单一材料纤维增强复合材料(Fiber Reinforced Polymer,FRP)锚杆固有的脆性特征以及延展性较差的问题,提出新型复合FRP锚杆——MFRP(Metal FRP)锚杆.该锚杆由中心的高延展性金属材料、外层的FRP以及连接金属材料和FRP的钢纤维层构成.根据复合材料混合法理论分析MFRP锚杆的延展性,并用MSC Marc模拟分析其协调性.MFRP的应力应变曲线及锚杆受拉力情况下界面剪应力表明:MFRP的延伸率比普通的FRP提高大约15倍;通过添加钢纤维层,MFRP的界面平均剪应力比未添加钢纤维层的材料减小一半左右,从而使界面间的变形更加协调. 相似文献