Effects on Zinc Stress on Stress-Resistance Physiological and Biochemical Indexes of Jatropha curcas seedlings

Jatropha curcas seedlings were cultured for 21 d under 6 zinc concentrations of 0,25,50,100,200,400 mg/l to study the effects of ZnS O4 stress on the mechanism of resistance to heavy metal stress of J. curcas seedlings. The results showed that with the increase of stress concentration,the content of chlorophyll-a decreased and the activity of POD first increased and then maintained at a certain level or decreased slowly. The contents of soluble sugar,malondialdehyde,soluble protein and free proline increased,and the root activity increased first and then decreased. The relative conductivity of J. curcas seedlings decreased first and then increased,which indicated that the leaves of J. curcas seedlings had some adaptability and self-repairing capability under zinc toxicity stress,but the adaptability and self-repair ability were limited.

Effects of Selenium and Zinc on Renal Oxidative Stress and Apoptosis Induced by Fluoride in Rats

Objective To study the effects of selenium and zinc on oxidative stress, apoptosis, and cell cycle changes in rat renal cells induced by fluoride. Methods Wistar rats were given distilled water containing sodium fluoride （50 mg/L NaF） and were gavaged with different doses of selenium-zinc preparation for six months. Four groups were used and each group had eight animals （four males and four females）. Group one, sham-handled control; group two, 50 mg/L NaF; group three, 50 mg/L NaF with a low dose of selenium-zinc preparation （0.1 mg/kg Na2 SeO3 and 14.8 mg/kg ZnSO4 · 7H2O）; and group four, 50 mg/L NaF with a high dose of selenium-zinc preparation （0.2 mg/kg Na2 SeO3 and29.6 mg/kg ZnSO4 · 7H20）. The activities of serum glutathione peroxidase （GSH-Px）, kidney superoxide dismutase （SOD）, and the levels of malondialdehyde （MDA） and glutathione （GSH） in the kidney were measured to assess the oxidative stress. Kidney cell apoptosis and cell cycle were detected by flow cytometry. Results NaF at the dose of 50 mg/L increased excretion of fluoride in urine, promoted activity of urine γ -glutarnyl transpeptidase （ γ -GT）, inhibited activity of serum GSH-PX and kidney SOD, reduce kidney GSH content, and increased kidney MDA. NaF at the dose of 50 mg/L also induced rat renal apoptosls, reduced the cell number of G2/M phase in cell cycle, and decreased DNA relative content significantly. Selenium and zinc inhibited effects of NaF on oxidative stress and apoptosis, promoted the cell number of G2/M phase in cell cycle, but failed to increase relative DNA content significantly. Conclusion Sodium fluoride administered at the dose of 50 mg/L for six months induced oxidative stress and apoptosis, and changes the cell cycle in rat renal cells. Selenium and zinc antagonize oxidative stress, apoptosis, and cell cycle changes induced by excess fluoride.

Role of zinc as an antioxidant and anti-inflammatory to relieve cadmium oxidative stress induced testicular damage in rats

Objective:To investigate the role of zinc in reducing the deleterious effects of cadmium on male gonads.Methods:Rats were injected subcutaneously with CdCl_2 and ZnCl_2 at dose level of2.2 mg/kg(1/40 of LD50 of cadmium per day).Results:The rats treated with cadmium exhibited a significant increase in levels of testicular malondialdehyde,tumor necrosis factor-alpha,nitrogen oxide and inducible nitrogen oxide synthase immunostaining reaction,as well as an elevation of blood hydroperoxide and follicle stimulating hormone.In addition,a significant decrease in testicular ascorbic acid,zinc,reduced glutathione,catalase,superoxide dismutase,sex organ weight,plasma testosterone and luteinizing hormone were observed in the cadmium group.Sperm motility and count were decreased with cadmium treatment,while sperm abnormalities elevated significantly.Zinc treatment was found to mitigate the toxic effects of cadmium on oxidative stress,spermatogenesis,sex hormones,and inflammatory markers.Rats injected with cadmium showed intense histopathological changes.Zinc manifested protective role and markedly reduced tissues damage induced by cadmium.Conclusions:The protective effect of zinc can be attributed to its antioxidant and antiinflammatory properties.

Temperature-dependent bias-stress-induced electrical instability of amorphous indium-gallium-zinc-oxide thin-film transistors

The time and temperature dependence of threshold voltage shift under positive-bias stress（PBS） and the following recovery process are investigated in amorphous indium-gallium-zinc-oxide（a-IGZO） thin-film transistors. It is found that the time dependence of threshold voltage shift can be well described by a stretched exponential equation in which the time constant τ is found to be temperature dependent. Based on Arrhenius plots, an average effective energy barrier Eτ stress= 0.72 eV for the PBS process and an average effective energy barrier Eτ recovery= 0.58 eV for the recovery process are extracted respectively. A charge trapping/detrapping model is used to explain the threshold voltage shift in both the PBS and the recovery process. The influence of gate bias stress on transistor performance is one of the most critical issues for practical device development.

Positive and Negative Environmental Effect of Using Zinc Oxide Nanoparticles on Wheat under Drought Stress

Nanoscience is a development concept in the field of agriculture. Water scarcity is one of the most serious stresses that restrict growth of plant. This search was done to value the positive and negative influence of ZnO nanoparticles on wheat plant growth under drought stress. A green synthesis technique was used to produce pollutant-free nano structures. A field experiment was carried out during successive season (2019/2020). NP-Zn-O was applied either by seed-soaking, foliar spraying, or both together applications. The dose of ZnO NPs was 100 mg/l. Data showed that drought stress reduced the grain and shoot wheat yield. The use of different forms of ZnO improved the grain and shoot wheat yield, these increases reached 1.16-, 1.54-fold that control. In addition, one of the other effects of Zn-O-NPs is to increase the levels of chlorophyll and proline antioxidants in plant tissues, as it is a cofactor for enzymes such as superoxide dismutase and catalase. The data suggest that the role of ZnO NPs is not only to improve plant growth and physiological parameters, but also to improve nutrient uptake and plant nutrient levels. In this regard, the use of zinc in the form of ZnO NPs has a positive effect on reducing the adverse effects of drought conditions and improving the nutritional quality of plants.

Improvement in the electrical performance and bias-stress stability of dual-active-layered silicon zinc oxide/zinc oxide thin-film transistor

Si-doped zinc oxide（SZO） thin films are deposited by using a co-sputtering method,and used as the channel active layers of ZnO-based TFTs with single and dual active layer structures.The effects of silicon content on the optical transmittance of the SZO thin film and electrical properties of the SZO TFT are investigated.Moreover,the electrical performances and bias-stress stabilities of the single- and dual-active-layer TFTs are investigated and compared to reveal the effects of the Si doping and dual-active-layer structure.The average transmittances of all the SZO films are about 90% in the visible light region of 400 nm-800 nm,and the optical band gap of the SZO film gradually increases with increasing Si content.The Si-doping can effectively suppress the grain growth of ZnO,revealed by atomic force microscope analysis.Compared with that of the undoped ZnO TFT,the off-state current of the SZO TFT is reduced by more than two orders of magnitude and it is 1.5 × 10^-12 A,and thus the on/off current ratio is increased by more than two orders of magnitude.In summary,the SZO/ZnO TFT with dual-active-layer structure exhibits a high on/off current ratio of 4.0 × 10^6 and superior stability under gate-bias and drain-bias stress.

Antioxidant role of zinc in diabetes mellitus

Chronic hyperglycemia statue noticed in diabetes mellitus favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity.Zinc plays an important role in antioxidant defense in type2 diabetic patients by notably acting as a cofactor of the superoxide dismutase enzyme,by modulating the glutathione metabolism and metallothionein expression,by competing with iron and copper in the cell membrane and by inhibiting nicotinamide adenine dinucleotide phosphate-oxidase enzyme.Zinc also improves the oxidative stress in these patients by reducing chronic hyperglycemia.It indeed promotes phosphorylation of insulin receptors by enhancing transport of glucose into cells.However,several studies reveal changes in zinc metabolism in individuals with type 2 diabetes mellitus and controversies remain regarding the effect of zinc supplementation in the improvement of oxidative stress in these patients.Faced with the serious challenge of the metabolic disorders related to oxidative stress in diabetes along with the importance of antioxidant nutrients in the control of this disease,new studies may contribute to improve our understanding of the role played by zinc against oxidative stress and its connection with type 2 diabetes mellitus prognosis.This could serve as a prelude to the development of prevention strategies and treatment of disorders associated with this chronic disease.

QUANTITATIVE CHARACTERIZATION OF STRESS-STRAIN HYSTERESIS LOOPS OF Cu-Zn-Al SHAPE MEMORY ALLOY

A six-parameter mathematical model was introduced to simulate the stress-strain hysteresis and the sinner hysteresis of polycrystalline shape memory alloys (SMAs). By the comparison with experiments of Cu-Zn-Al SMA, it was shown that the model could be used to calculate the stress-strain relations with rather good accuracy. Moreover, it was found that the six parameters introduced in this paper represented the characteristics of the stress-strain hysteresis of polycrystalline SMAs and could be used to characterize the hysteresis quantitatively.

Gene Expression and Activities of SOD in Cucumber Seedlings Were Related with Concentrations of Mn^(2+),Cu^(2+),or Zn^(2+) Under Low Temperature Stress

Effects of increasing Mn^2＋, Cu^2＋, or Zn^2＋ on SOD expressions were studied in cucumber seedlings under low temperature stress. Both gene expressions and activities of Cu/Zn-SOD and Mn-SOD in cucumber seedling leaves were induced by increasing Mn^2＋, Cu^2＋, or Zn^2＋ under low temperature stress, especially 48 h afterwards. The activities of Cu/Zn-SOD and Mn-SOD at 0 and 48 h after treatment were in accordance with their gene expression levels, which implied that the transcriptional regulation plays key roles in regulating their activities at the early stage of low temperature stress. Gene expressions of Cu/Zn-SOD and Mn-SOD declined at 96 h, but Cu/Zn-SOD and Mn-SOD activities still remain high, which suggested that Cu/Zn-SOD and Mn-SOD activities might be regulated by other factors after transcription at the later stage of low temperature stress. Therefore, we concluded that the increasing Mn^2＋, Cu^2＋, or Zn^2＋ could increase the capacity of scavenging ROS in cucumber seedlings under low temperature stress by inducing gene expressions of Cu/ Zn-SOD and Mn-SOD, elevating activities of Cu/Zn-SOD, Mn-SOD, or regulating other factors after transcription.

Strain and stress analysis on Zn multicrystal film by XRD method

A new method was denonstrated to determine stress in a single crystal for multicrystal material and this new method could be specially applied for any symmetric crystalline systems. The strain tensor e was determined by the change of the metric tensor G before the initial state and after the deformed state in the crystal reference system. Then stress tensor at grain scale was calculated by the HOOK's law. The stress evaluations were carried out in coarse grains of a thin galvanized coating on a steel substrate during tensile loading. This makes it possible to link the microstructure evolution to the elastic heterogeneity at grain scale or between the grains.

Characterization and expression analysis of a novel RING-HC gene,ZmRHCP1,involved in brace root development and abiotic stress responses in maize

RING is a really interesting new gene which plays important regulatory roles in many developmental processes as well as in plant-environment interactions. In the present report, the Zm RHCP1 gene encoding a putative RING-HC protein was isolated from maize and characterized. The Zm RHCP1 protein contained 310 amino acid residues with a conserved RINGHC zinc-finger motif and two transmembrane（TM） domains. Zm RHCP1 was expressed ubiquitously in various organs（root, stem, leaf, seedling, immature ear, and tassel）, but its transcript levels were higher in vegetative organs than in reproductive organs. Moreover, the expression pattern of Zm RHCP1 in brace roots indicated that Zm RHCP1 functions in brace root initiation. In addition, Zm RHCP1 expression was regulated by abiotic stresses. The expression results suggested that Zm RHCP1 plays important roles in brace root development and abiotic stress responses. The findings of the present study provide important information to help us understand the function of Zm RHCP1 in maize.

Molecular Characterization and Expression Analysis of TaZFP15, a C_2H_2-Type Zinc Finger Transcription Factor Gene in Wheat (Triticum aestivum L.)

Based on sequencing of part clones in a root subtractive cDNA library, an expressed sequence tag （EST） sharing high similarity to a rice C2H2 zinc finger transcription factor （ZFP15） was obtained in wheat. Through bioinformatics approach, the wheat C2H2-type ZFP gene referred to TaZFP15 has been identified and characterized. As a full-length cDNA of 670 bp, TaZFP15 has an open reading frame of 408 bp and encodes a 135-aa polypeptide. TaZFP15 contains two C2H2 zinc finger domains and each one has a conserved motif QALGGH. The typical L-box, generally identified in the C2H2 type transcription factors, has also been found in TaZFP15. Phylogenetic analysis suggested that TaZFP15 shares high similarities with rice ZFP15 （GenBank accession no. AY286473）, maize ZFP （GenBank accession no. NM_001159094） and a subset of other zinc-finger transcription factor genes in plant species. The expression of TaZFP15 was up-regulated by starved-Pi stress, showing a pattern to be gradually elevated along with the progression of the Pi-stress in a 23-h treatment regime. Similarly, the transcripts of TaZFP15 in roots were also induced by nitrogen deficiency, and abiotic stresses of drought and salinity. No responses of TaZFP15 were detected in roots to nutrition deficiencies of P, Zn, and Ca, and the external treatment of abscisic acid （ABA）. TaZFP15 could be specifically amplified in genome A, B, and D, and without variability in the sequences, suggesting that TaZFP15 has multi-copies in the homologous hexaploid species. Transgenic analysis in tobacco revealed that up-regulation of TaZFP15 could significantly improve plant dry mass accumulation via increasing the plant phosphorus acquisition capacity under Pi-deficiency condition. The results suggested that TaZFP15 is involved in mediation of signal transductions of diverse external stresses.

Zinc Chloride Protects against Streptozotocin-Induced Diabetic Nephropathy in Rats

Diabetes mellitus (DM) is a health problem affecting millions of individuals worldwide. Diabetic nephropathy (DN), as a significant complication of DM, has become the most common cause of endstage renal failure. Oxidative stress constitutes the key and common events in the pathogenesis of DN and antioxidants may play a beneficial role in its prevention. This study was conducted to investigate the effect of Zinc Chloride on streptozotocin-induced diabetic nephropathy in rats compared to Gliclazide, a reference antidiabetic agent. Results showed that Zinc Chloride was able to control STZ-induced DN in rats as it normalized the elevated blood pressure, the increased insulin release, and the decreased blood glucose level. Zinc Chloride also improved kidney function as determined by the restoration of blood urea and creatinine level. Finally, Zinc Chloride was able to boost the antioxidant defenses of the kidney by increasing the reduced glutathione content and decreasing lipid peroxides content in addition to significantly decreasing kidney nitric oxide content compared to diabetic control rats. These results suggest that exposure to Zinc Chloride can protect from diabetic nephropathy and can be used as an adjuvant approach to treatment and prevention of renal damage.

Flow Stress Behavior of Cu13Zn Alloy Deformed at Elevated Temperature

The flow stress behavior of Cu13Zn alloy was investigated by compression tests carried out at 650 ℃, 700 ℃, 750 ℃, 850 ℃, and constant strain rates of 0.05 s -1 , 0.1 s -1 , 0.5 s -1 , 1 s -1 , 5 s -1 , respectively. The results show that the flow stress increases with the increase of strain and reaches a steady state stress, and the saturated stress ( σ s) increases with the increase of the strain rate and the decrease of temperature. Flow stress curves of the alloy deformed at elevated temperatures can be simulated effectively by the model proposed by Zhou and Clode, and the flow stress is described as a function of strain, strain rate and temperature. Material constants values are: Q =270.43 kJ/mol, α =0.020 94, A =1.747×10 11 s -1 and n = 3.549 mm 2·N -1 , the deformation mechanisms of the alloy are self diffusion and dynamic recovery.

滇杨幼苗对镉、锌胁迫的生理响应与耐受性研究

为探究滇杨幼苗在Cd、Zn单一及复合胁迫下的生长、生理响应与耐受特征,采用土培盆栽的方式开展研究。结果表明:Cd、Zn单一及复合胁迫未显著改变滇杨株高、地径和总生物量,但单一Zn胁迫显著提高总根长、根表面积和根体积,Cd-Zn胁迫显著降低总根长;Zn可改善滇杨的苗木生长质量,Cd可导致滇杨生长变差,而Cd-Zn复合胁迫时生长状况最差。Cd、Zn单一胁迫未显著改变滇杨叶片的光合色素含量和净光合速率,Cd-Zn复合胁迫时叶绿素含量显著降低,但净光合速率和光响应特征参数变化不显著,而Cd单一胁迫时滇杨的R_(d)和LCP较CK显著增高,Zn单一胁迫时则LSP显著增高。Cd和Cd-Zn胁迫可激发滇杨氧化应激防御系统,使SOD和CAT活性显著提高,MDA和TPh含量无显著变化,Zn胁迫时SOD、CAT、MDA和TPh含量均无显著变化。滇杨幼苗对Cd、Zn单一及复合胁迫表现出耐受性,可作为Cd、Zn污染土壤生态修复的重要候选树种,其综合耐受值为Zn>CK>Cd>Cd-Zn。

Positive gate bias stress-induced hump-effect in elevated-metal metal-oxide thin film transistors

Under the action of a positive gate bias stress, a hump in the subthreshold region of the transfer characteristic is observed for the amorphous indium-gallium-zinc oxide thin film transistor, which adopts an elevated-metal metal-oxide structure. As stress time goes by, both the on-state current and the hump shift towards the negative gate-voltage direction. The humps occur at almost the same current levels for devices with different channel widths, which is attributed to the parasitic transistors located at the channel width edges. Therefore, we propose that the positive charges trapped at the back-channel interface cause the negative shift, and the origin of the hump is considered as being due to more positive charges trapped at the edges along the channel width direction. On the other hand, the hump-effect becomes more significant in a short channel device （L=2 μm）. It is proposed that the diffusion of oxygen vacancies takes place from the high concentration source/drain region to the intrinsic channel region.

硫酸锌胁迫对萌发青稞功能成分及抗氧化能力的影响

该研究以藏青2000为原料,采用酶联免疫吸附法等方法测定了不同浓度硫酸锌胁迫下萌发青稞的功能成分含量及抗氧化能力,同时记录其萌发率等指标。结果表明,硫酸锌胁迫对青稞的萌发率、水分含量、根长和芽长有抑制作用。随着时间的延长,在不同浓度硫酸锌胁迫下,褪黑素、γ-氨基丁酸含量先增加后降低;还原糖、可溶性含量先上升后达到动态平衡;β-葡聚糖、总黄酮及总酚含量先降低后升高。其中,0.6 mmol/L硫酸锌胁迫萌发第7天时总酚含量是对照组的1.12倍;0.8 mmol/L硫酸锌胁迫萌发第6天时褪黑素与γ-氨基丁酸含量分别是对照组的1.35、1.40倍,第7天时总黄酮含量是对照组1.28倍。抗氧化能力结果显示,萌发青稞的抗氧化能力与其含有的总黄酮总酚含量显著正相关(P<0.01)。综上,萌发可改善青稞品质,0.6~0.8 mmol/L的硫酸锌胁迫可有效提高萌发青稞功能成分含量及抗氧化能力。

铜锌复合胁迫下禾本科观赏草的富集、转运效应评价

研究禾本科观赏草在土壤重金属铜、锌复合污染下的富集、转运效应,筛选出耐性品种,为挖掘超富集植物及推动利用植物修复铜、锌污染环境提供参考依据。以9种常见禾本科观赏草作为试验植材,设置5个胁迫梯度,采用盆栽控制法,探究供试观赏草体内铜、锌含量分布状况并分析其对铜、锌的富集能力与转运特征。结果表明,不同供试观赏草吸收重金属铜、锌的能力存在差异;不同部位吸收重金属铜、锌的能力亦差异显著,供试观赏草地上部吸收锌的能力强于地下部,而地下部吸收铜的能力强于地上部。供试观赏草富集、转移锌的能力均强于铜,在锌富集系数、转运系数方面高于铜。采用隶属函数法及Q型聚类分析法,当相对距离为7.5时,可将供试观赏草划分为高、中、低铜锌积累型3类,丽色画眉草、细叶芒综合表现最强且属于高铜锌积累型。

基于转录组测序技术研究黑水虻幼虫对锌离子胁迫的响应

黑水虻Hermetia illucens L.是世界范围内重要资源昆虫,过量锌离子(Zn^(2+))胁迫会对其幼虫的生长发育产生影响,而转录组分析有助于揭示Zn^(2+)胁迫影响黑水虻幼虫发育的分子机制。本试验以不同浓度Zn^(2+)(75、150、300、1200 mg/kg)对黑水虻幼虫进行连续5代胁迫,利用Illumina HiSeq 4000高通量测序平台对第5代6龄幼虫转录组进行测序及分析。结果显示,Zn^(2+)胁迫影响了第5代黑水虻幼虫的基因表达水平,75、150、300和1200 mg/kg Zn^(2+)处理幼虫中上调/下调的差异表达基因分别是1293/1839、1277/2306、1080/1966和1444/2170个;GO富集分析结果表明,差异表达基因在细胞过程中所占比例最大,细胞组分中主要是细胞和细胞成分,分子功能中主要为催化活性和细胞结合;KEGG富集差异分析显示,75 mg/kg Zn^(2+)胁迫下差异表达基因主要富集在免疫相关反应、免疫相关信号传导途径及脂类物质代谢,300 mg/kg Zn^(2+)处理组差异表达基因主要富集在氨基酸代谢和碳水化合物代谢;1200 mg/kg Zn^(2+)胁迫下氨基酸和脂类代谢、免疫相关反应和生长均受到严重影响,这些富集的与上述有关的差异基因大多表达下调。本研究表明,Zn^(2+)胁迫影响了黑水虻幼虫基因表达,高浓度Zn^(2+)胁迫基因表达影响尤为显著,主要表现在细胞过程、催化活性和结合的基因表达下调;高浓度Zn^(2+)胁迫还导致了黑水虻幼虫免疫系统、环境相关信号传导途径和脂质代谢等的紊乱。

叶面硅、锌肥对镉胁迫下小麦幼苗生长的影响

【目的】探讨镉胁迫下喷施叶面硅锌肥对小麦生长发育及小麦Cd积累量的影响。【方法】试验以川麦602号小麦为材料,采用水培试验模拟Cd污染的条件,对小麦幼苗进行单施叶面硅肥、锌肥和配施3种处理。【结果】(1)在Cd胁迫下,叶面硅、锌肥提高了植物生物量和叶绿素含量,其效果Si>Si&Zn>Zn;(2)单独喷施叶面硅、锌肥和混合喷施硅锌肥均降低了小麦地上部Cd含量,分别降低了30.31%、16.41%、14.16%;(3)喷施叶面肥还通过降低丙二醛(MDA)和过氧化氢(H2O2)来缓解小麦叶片的氧化应激,并提高了超氧化物歧化酶(SOD)和愈创木酚过氧化物酶(POD)活性。【结论】镉胁迫下喷施叶面硅、锌肥可以促进小麦幼苗的生长发育,增强抗氧化酶活性,提高抗氧化能力,降低对Cd的吸收,从而减轻Cd对小麦幼苗的毒害,其中单施叶面硅肥效果最佳。