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1.
Micronutrient malnutrition is a global health issue and needs immediate attention. Over two billion people across the globe suffer from micronutrient malnutrition. The widespread zinc (Zn) deficiency in soils, poor zinc intake by humans in their diet, low bioavailability, and health consequences has led the research community to think of an economic as well as sustainable strategy for the alleviation of zinc deficiency. Strategies like fortification and diet supplements, though effective, are not economical and most people in low-income countries cannot afford them, and they are the most vulnerable to Zn deficiency. In this regard, the biofortification of staple food crops with Zn has been considered a useful strategy. An agronomic biofortification approach that uses crop fertilization with Zn-based fertilizers at the appropriate time to ensure grain Zn enrichment has been found to be cost-effective, easy to practice, and efficient. Genetic biofortification, though time-consuming, is also highly effective. Moreover, a Zn-rich genotype once developed can also be used for many years without any recurring cost. Hence, both agronomic and genetic biofortification can be a very useful tool in alleviating Zn deficiency.  相似文献   

2.
人们对儿童锌缺乏症的认识不足、误诊误治、检测过程复杂、药品剂型单调是锌缺乏防治存在的问题。相应对策应考虑组织专业服务,建立防治网;加强普及锌缺乏防治知识;改进检测方法和开发多元化的锌制剂品种。  相似文献   

3.
籽粒铁、锌营养与人体健康研究进展   总被引:1,自引:0,他引:1  
综述了解决人体微量元素缺乏的几种途径,即药物防治、饮食多样化、食品防御工程和生物防御工程。认为生物强化工程即通过育种途径来增加籽粒中微量元素含量以其节省费用、持久性、广泛性和安全性之优点而更具发展潜力。同时,总结了国内外关于籽粒微量元素营养,尤其是铁和锌营养的最新研究进展,并提出了农业工作者在该领域的切入点。  相似文献   

4.
Zn 还原过渡金属化合物制备金属粉体的过程   总被引:7,自引:0,他引:7  
用Zn粉还原过渡金属Fe、Co、Ni和Cu的硫酸盐和硫酸铵复盐溶液,获得了相应金属的纳米粉体.详细研究了此反应的还原过程.用XRD、SEM、TEM和ED等方法对产物进行了表征,发现析出的粉体不同程度上均生成有Zn置换的固溶体. Fe在Zn粒外层生成薄层Fe-Zn固溶体,Ni和Co为粒径分别为7.5 nm和12.1 nm的Zn饱和固溶体, Cu则在外层生成Cu5Zn8的新相.讨论了还原过程的机制,认为和M-Zn电池电动势的驱动力有关.  相似文献   

5.
镉及镉锌交互作用的植物效应   总被引:7,自引:0,他引:7  
镉是植物生长的非必需元素,而锌是植物生长必需的微量元素。虽然它们对植物的作用截然相反,但它们之间存在着复杂的交互影响关系。总结了镉对植物的生物效应,镉锌交互作用对植物的影响,包括:对元素的吸收积累,酶活性,细胞分裂等,论述了其主要影响因素,并探讨了Cd—Zn拮抗和Cd—Zn协同作用的可能机理。  相似文献   

6.
The trace element content of the total daily diet (food and beverages) of each of 4 adult males was determined over a period of one week. A method of radiochemical neutron activation analysis is briefly described which enables the determination of up to 31 elements in biological samples. Of the 25 elements determined in the diet 12 are essential elements (Ca, Cl, Co, Cr, Cu, Fe, K, Mn, Mo, Na, Se, Zn) while 6 (As, Ba, Br, Cd, Hg, Sb) are classified as toxic. The average concentrations of the toxic trace elements As, Cd and Hg of the diet are below the provisional tolerable dietary intakes recommended by WHO/FAO. The contents of Cl, Cu, Fe, K, Mn, Na and Zn are adequate to the proposed nutritional requirements.  相似文献   

7.
对795例儿童锌缺乏征进行了分析,结果显示,儿童的缺乏时有多种临床表现,发生率依次为食欲异常,生长迟缓,免疫功能低下,智力发育障碍。  相似文献   

8.
Aim of this work was to investigate which are the effects on barley crops grown on two different soils: a soil lacking in Cu, an essential micronutrient (A) and a naturally polluted soil rich in lead, zinc, copper (B). In particular we investigated the relationship between some ecophysiological parameters such as biomass, chlorophyll concentration and guaiacolo peroxidase activity and the chemical-physical properties of the soils like pH, organic matter and heavy metal content. Because metals uptake by plants is strongly correlated with the bioavailable fraction rather then their total amount in a soil, we have measured also metal exchangeable forms, using a single extraction method (MgCl2 as extractant). Plants grown on soil B showed a metal content higher than background limits, whereas plants grown on soil A were characterised by a background Fe and Zn concentrations and by a tolerant Pb concentration. Conversely, Cu content in tissues of plants grown in soil A is found to be under the background limits. Copper-deficiency plants present chlorotic leaves followed by a reduced clorophyll content, while plants grown on metals contaminated soil showed an increase of peroxidase activity.  相似文献   

9.
Zn2+ release from Zn and ZnO particles with different sizes in simulated uterine solution were investigated by absorbance measurements. The effects of pH and human serum albumin (HSA) on Zn2+ release were also studied. The morphology of Zn and ZnO particles was observed by scanning electron microscopy, and the corrosion products of zinc nanoparticles were analyzed by XRD. The results indicate that the maximum release ratios of Zn2+ from Zn and ZnO nanoparticles are higher than those from Zn and ZnO microparticles. Zn2+ release ratio depends not only on the pH of the simulated uterine solution but also the presence of human serum albumin. It decreases as the pH of the uterine solution increases. The trends of Zn2+ release ratios are almost the opposite for solutions with and without HSA. XRD analysis results indicate that zinc oxide is the main corrosion product of zinc particles.  相似文献   

10.
So far, Zn(II)-based d10 complexes have been known to be colorless unless they are accompanied by chromophoric groups, and therefore both fundamental and advanced photophysical performance of Zn centers of complexes, especially in visible-light regions has been unexplored. Here, we first demonstrate a dinuclear Zn(II) complex that shows visible light absorption using an orbital distributed over closely contacted two Zn centers experimentally determined by X-ray crystallography. A contrastive study demonstrated that intermetallic orbital interaction in dinuclear Zn(II) complex is responsible for capturing visible light to exhibit orangish yellow color, whereas an analogous one without such an interaction is colorless. This work demonstrates that introduction of Zn−Zn interactions to Zn(II) molecules contradicts the common notion that Zn is unresponsive to visible light and expands the photophysical field of zinc chemistry.  相似文献   

11.
采用浸渍法制备了Zn负载量(质量分数)分别为1%、2%、3%的Zn/HZSM-5分子筛催化剂,通过XRD、N2吸附-脱附、NH3-TPD、Py-FTIR、XPS、TG-DTA等技术,系统考察Zn/HZSM-5分子筛在乙烯芳构化反应的失活机制。结果表明,积炭是催化剂失活的主要原因,HZSM-5中Zn的添加在较大程度上抑制了催化剂的积炭行为;低Zn含量时催化剂失活缓慢,但Zn含量较高时,由于催化剂比表面积和孔体积极剧下降,催化剂失活加剧。反应过程中,分子筛上Zn物种存在迁移和流失行为,迁移行为体现为催化剂表面Zn的富集和相对比例的变化;Zn流失速率在不同反应阶段保持恒定,但受到Zn含量的影响,Zn含量越高、流失速率越大。外表面ZnO是分子筛催化剂Zn流失的主要物种,且随Zn负载量升高变化趋势愈加明显,其含量与积炭速率存在一定关联。  相似文献   

12.
Rechargeable aqueous zinc-ion batteries (ZIB) sparked a considerable surge of research attention in energy storage systems due to its environment benignity and superior electrochemical performance. Up to now, less efforts to delve into mechanisms of zinc metal anode and their electrochemical performance. Zn metal anodes sustain thorny issues with Zn dendrite growth, hydrogen evolution reaction, and Zn corrosion irreversible byproduct formation, which results in low coulomb efficiency (CE) and poor cycle ability of the battery. Herein, we reveal the fundamental understanding of the above issue, outline four step, including mass transfer, desolvation process, charge transfer and Zn cluster formation. It can be clearly seen from reported strategies to promote Zn anode stability that deals with one or more steps, thereby boosting the understanding of the issues of Zn anodes and benefiting the rational design to surmount the issue. We also sum up advanced materials and structure design such as the design of the anode surface and internal structure, electrolyte strategies, and multifunctional separators. Finally, possible tactics and future innovation direction for Zn-based batteries are proposed to achieve high performance aqueous Zinc-ion batteries.  相似文献   

13.
14.
对湛江地区612例健康儿进行了头发锌、钙、铜、铁检测。发现婴儿斯铁偏低,幼儿期以缺锌、缺钙明显,学龄期缺锌为甚,铜在各年龄组较恒定在正常范围。各年龄组微量元素值女童比男童偏高。故在各时期要注意平衡膳食,预防微量元素缺乏症,应从婴儿期开始。  相似文献   

15.
Zinc (Zn) is a trace element that is, as a building block in various enzymes, of vital importance for all living organisms. Zn concentrations are widely determined in dietary, biological and environmental studies. Recent papers report on the first efforts to use stable Zn isotopes in environmental studies, and initial results point to significant Zn isotope fractionation during various biological and chemical processes, and thus highlight their potential as valuable biogeochemical tracers. In this article, we discuss the state-of-the-art analytical methods for isotopic analysis of Zn and the procedures used to obtain accurate Zn isotope ratio results. We then review recent applications of Zn isotope measurements in environmental and life sciences, emphasizing the mechanisms and causes responsible for observed natural variation in the isotopic composition of Zn. We first discuss the Zn isotope variability in extraterrestrial and geological samples. We then focus on biological processes inducing Zn isotope fractionation in plants, animals and humans, and we assess the potential of Zn isotope ratio determination for elucidating sources of atmospheric particles and contamination. Finally, we discuss possible impediments and limitations of the application of Zn isotopes in (geo-) environmental studies and provide an outlook regarding future directions of Zn isotope research.  相似文献   

16.
目前由人工合成的有机螯合微量元素肥料,因价格昂贵不能在农业生产中广泛应用。本研究采用丰富廉价的有机肥料,经转化提取的天然螯合剂与微量元素螯合研制的天然螯合微肥,在多种作物上施用,证明能促进作物对N、P、K和Fe、Mn、Zn、Cu等微量元素的吸收。明显提高作物的产量,改善品质,并不同程度地提高作物的抗病能力.  相似文献   

17.
微量元素锌与人类健康有着非常密切的关系,尤其在促进儿童生长发育方面,更令人注目,因此如何预防和治疗儿重锌缺乏症是医务人员急需研究解决的课题。儿童缺锌的原因多是由于生长发育迅速,对锌的需要量增加而又得不到充足的供应,或是由于偏食和饮食失调而引起。但锌不能由体内合成,主要是来自食物.在传统的祖国医学宝库中.饮食疗法已有二千多年的历史.在科学育儿方面.应充分发挥中医饮食疗法的优势。因中医饮食疗法具有整体观念和辩证施食的特点.食疗又是儿童乐于接受的。把含锌量高的食物与食物的性味功能有机地结合起来.配成滋阴健脾益胃和清热除烦,消积滞的汤水.用辩证施食的方法对30例缺锌儿童进行试用.经3个月食疗调理后复查.缺锌儿食欲普遍增加。烦燥症状明显改善.头发锌复查有半数以上恢复到正常值.从而揭示了饮食疗法是预防缺锌的一个较理想的途径。  相似文献   

18.
合成了一种Zn2+荧光探针N-(8-对氨基苯磺酰)胺基喹啉(HQAS),探讨了HQAS与Zn2+的键合比和配位模式,以及不同pH,其它金属离子对Zn2+检测的影响.研究结果显示:该探针与Zn2+形成配合物,使其荧光增强,键合比为2:1,pH 7.2时荧光强度增大9.4倍.大多数金属离子几乎不干扰Zn2+的检测,Cu2+...  相似文献   

19.
测定了1000名孕妇发中Zn、Cu含量,发现低Zn率为19.8%,Cu不足占52.9%,可能与环境、饮水、膳食等因素有关。统计分析表明,两种元素均呈不对称分布,Zn与Cu呈正相关,Zn与Zn/Cu比值为负相关。  相似文献   

20.
用火焰原子吸收法检测了反复呼吸道感染儿童头发中锌的含量,用放免法检测血清IgA的含量。结果表明,患病组儿童的发锌值和血清IgA值均低于正常组儿童(P<0.05)。患儿经补锌治疗1年后,总有效率达82.1%,发锌及血清IgA含量均增加,表明缺锌所导致的IgA含量下降,呼吸道粘膜分泌IgA缺乏是儿童反复呼吸道感染的重要原因之一,补充锌可有效提高患儿的免疫力,治疗儿童反复呼吸道感染。  相似文献   

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