钒在枸杞幼苗中积累、转运及亚细胞分布

通过沙培实验和采用差速离心技术,研究了钒(V)在枸杞幼苗中的积累、转运和亚细胞分布特征.结果表明:V在枸杞不同器官中的含量和分配比例为根＞茎＞叶,随着V处理浓度的增加,枸杞幼苗根中V含量和分配比例显著增大,在V处理浓度为20mg· L-1时,根中V含量达19.80 μg·g-1,占总量的60.1％.枸杞幼苗在V浓度为2、5 mg· L-1时,根富集系数BCF＞1,转运系数TF＜1,表明枸杞植物对V有较强的富集能力,但转运能力较低,其积累的V主要富集在枸杞植株根部,可减轻过量V对茎叶的毒害.V在枸杞叶片中的亚细胞分布规律为F1(细胞壁)＞F4(可溶性组分)＞F2(细胞核)＞F3(线粒体和叶绿体).V在细胞壁和可溶性组分中所占的比例分别为28.3％～52.4％和4.1％～45.2％,表明细胞壁是V在枸杞叶片细胞中的重要分布位点.随着V处理浓度的增加,V在细胞壁中的分配比例减少,而可溶性组分的分配比例相应增加,细胞核、线粒体和叶绿体的分配比例显著下降.细胞壁和细胞质可溶性组分的相互协调,对植物自身解毒重金属起着重要作用,从而增强枸杞植物对重金属V的耐性.     

钒对小鼠肌肉中谷胱甘肽过氧化物酶活性的影响

观察钒对小鼠肌肉中谷胱甘肽过氧化物酶(GSH-PX)活性的影响。用健康小鼠32只,随机分为4组。Ⅰ、Ⅱ、Ⅲ组分别混饮10、5、2.5 mg/kg的偏钒酸铵,Ⅳ组为对照组,饮用蒸馏水,持续饮用20 d,利用谷胱甘肽过氧化物酶测试盒测定肌肉中的GSH-PX活性。结果表明,Ⅰ组肌肉中GSH-PX活性降低极显著(P<0.01),Ⅱ组显著降低(P<0.05),Ⅲ组肌肉中GSH-PX活性升高,但差异不显著(P>0.05)。说明偏钒酸铵在5 mg/kg~10 mg/kg剂量范围内可使肌肉中谷胱甘肽过氧化物酶活性降低。     

Sb(Ⅲ)和Sb(Ⅴ)在不同吸附剂上的吸附特征

以氢氧化铁、氢氧化铝、高岭土和蛭石4种材料为吸附剂,探究Sb(Ⅲ)和Sb(Ⅴ)的吸附效果,以类比土壤中主要矿物对Sb的吸附作用并进行对比。研究内容包括吸附动力学试验、等温吸附试验及不同背景溶液pH变化下的吸附解吸效应。结果表明:4种吸附剂对Sb(Ⅲ)和Sb(Ⅴ)的吸附在振荡24 h后逐渐趋于平稳,蛭石和氢氧化铁对Sb(Ⅲ)的吸附量在6 h达到峰值后出现下降,如氢氧化铁在6 h时对Sb(Ⅲ)的吸附量为23.19μg/g,72 h后降为19.75μg/g,并测定出该悬浮液中Sb(Ⅴ)浓度上升。用Langmuir和Freundlich吸附模型对两种价态Sb的等温吸附曲线进行拟合,两种模型拟合优度均在0.7以上。蛭石和氢氧化铁对Sb(Ⅲ)的吸附效果好于另两种吸附剂,而蛭石对Sb(Ⅴ)的吸附能力较弱;氢氧化铁和氢氧化铝对Sb(Ⅴ)的吸附效果较好,而氢氧化铝对Sb(Ⅲ)吸附效果不理想。随着pH的增加,Sb(Ⅲ)和Sb(Ⅴ)的吸附出现明显下降,并且解吸率增加,表现出pH对吸附的显著影响,如高岭土对Sb(Ⅲ)的吸附量由平衡液pH为4.82时的10.12μg/g增加到pH为2.12时的37.89μg/g。     

纳米LDHs-DGT用于土壤环境无机砷提取检测技术研究

为有效测量土壤环境中的砷污染,本研究开发了一种基于纳米层状双金属氢氧化物(LDHs)为结合膜的梯度扩散薄膜设备(LDHs-DGT)。对设备的基本性能以及适用条件进行了探究,对不同水分管理下土壤As(Ⅲ)和As(Ⅴ)的动态变化进行监测,探究了不同水分管理下的不同深度砷的形态变化情况,实验结果表明,该技术能够在较宽的pH(4～8)和离子强度(CNaNO₃<0.7 mol·L^-1)范围内对As(Ⅲ)和As(Ⅴ)进行有效的提取和检测,其中,LDHs结合膜对As(Ⅲ)和As(Ⅴ)的吸附容量分别为30μg·cm^-2和85μg·cm^-2,结合膜在6 h内实现全解离;且LDHs-DGT具有较好的抗干扰特性,As(Ⅲ)和As(Ⅴ)在结合膜上没有明显的竞争吸附效应,对实际样品测定结果也能较好地反映DGT设备的实用性。综上所述,LDHs-DGT具有制备简单、适用范围广、检测效果好等特点,可为环境监测和评估提供新的解决方案。     

环氧树脂作还原剂制备Li3V2(PO4)3的结构和性能

采用高温固相法，以环氧树脂为还原剂合成锂离子电池正极材料Li3V2(PO4)3.通过X射线衍射分析和扫描电子显微镜对样品的晶体结构和微观形貌进行表征，并用恒电流充放电和循环伏安实验研究材料的电化学性能.结果表明所制备的Li3V2(PO4)3为结晶完善的单斜结构，颗粒分布均匀且粒径较小，0.2 C时在3.0V~4.3V电压范围的首次放电比容量为126.9 mAh/g，30次循环后的比容量为126.0 mAh/g，容量保持率达到99.29%.     

Chronic Vanadium Poisoning in Calves and Its Treatment with Calcium Disodium Ethylenediaminetetraacetate

Sixteen Friesland heifer calves aged between 96 and 157 days were removed from a dairy farm that had been polluted with vanadium and randomly allocated into two equal groups (n = 8). The objective of the trial was to determine whether calcium disodium ethylenediaminetetraacetate (CaNa₂EDTA) could be used as a treatment for cattle running in environments high in background vanadium. The treatment group received 80 mg CaNa₂EDTA per kg body weight intraperitonealy (i.p.) twice a week over a 10-week period. The control group received normal saline i.p. over the same period. During the trial calves were exposed to a daily intake of vanadium in the form of contaminated tef hay derived from the farm of origin. In addition, the total mixed ration was spiked with a further 20 mg V₂O₅/kg feed to compensate for possible on-farm inhalation exposure. A stochastic model was used to estimate daily intake of vanadium as a distribution function. The model estimated that the daily intake of vanadium varied between an absolute minimum of 33 mg/day to an absolute maximum of 124 mg/day. The average intake of vanadium was 71.8 mg per day per calf. Various chemical pathology parameters were measured throughout the trial as well as urine excretion rates of vanadium and lymphocyte stimulation counts. All calves were slaughtered and necropsied in cohorts of 4–6 animals at monthly intervals after completion of the trial and withdrawal of vanadium from the ration. Tissue concentrations of vanadium were determined and necropsy findings were noted. The study found that CaNa₂EDTA appears to enhance the excretion of vanadium in calves, but could not prove that the treatment had a protective effect against vanadium exposure. Calves were able to tolerate the prolonged treatment with CaNa₂EDTA without side-effects.     

Hypoglycemic effects of vanadium on alloxan monohydrate induced diabetic dogs

The hypoglycemic effects after oral administration of vanadium have been studied previously in many species such as rats, mice and even humans. However, there has been no prior report on the glucose lowering effect of vanadium on diabetic dogs. Therefore, the purpose of this study was to evaluate the hypoglycemic effects of oral vanadium on diabetic dogs. Diabetes mellitus in the dogs studied was induced by alloxan monohydrate intravenous injection. The dogs were divided into two groups, one was the diabetic control (DC) group (n = 4) and the other was the vanadium treated (DV) group (n = 6). Fresh water was supplied to the dogs in the DC group, but sodium metavanadate solution (0.1~0.2 mg/ml) was given to the dogs in DV group from one week after the alloxan injection. The fasting glucose levels, fructosamine and serum chemistry profiles were compared between the two groups weekly for three weeks. The fasting blood glucose levels in DV group were significantly lower than those in the DC group (p < 0.01). Fructosamine levels in the DV group were also lower than those in the DC group (p < 0.05). The serum chemistry profiles were not significantly different in comparisons between the two groups. However, the cholesterol levels were significantly lower in the DV group compared to the DC group (p < 0.05). Our findings showed that oral vanadium administration had a hypoglycemic effect on chemically induced diabetic dogs.     

Vitamin C Overcomes the Detrimental Effect of Vanadium on Brown Eggshell Pigmentation

Phosphorus supplementation from poor quality feed-grade sources may introduce excessive levels of vanadium (V) into the diets of laying hens. Vanadium in the diet of chickens has been shown to be detrimental to egg production, albumen height, BW, and feed consumption. This study showed that dietary V also has a negative effect on the color of brown eggshells from commercial-type layers. Commercial-type brown egg layers were fed a cornsoybean meal basal diet supplemented with 0, 50, or 100 ppm of V as NH₄ VO₃ to determine the effect on shell pigmentation. Hens fed V at both dietary concentrations laid lighter colored eggs (less redness) after only 2 d. Another experimental group of the same type of hens that were fed lower V concentrations (0, 15, or 30 ppm) also had less shell pigmentation. After the detrimental “bleaching” effect on shell color was observed, these diets were supplemented with 1 of the following: no supplement, 100 ppm of vitamin C, 100 IU of vitamin E, or 100 ppm of β-carotene. Only vitamin C restored the eggshell color of eggs from hens fed both levels of V. When these same antioxidants were added as preventive agents to diets supplemented with 15 ppm of V before the effects of V were established, brown layers benefited again from 100 ppm of vitamin C but not from vitamin E or β-carotene.     

聚吡唑硼酸盐及其钒配合物的研究进展

基于钒-聚吡唑硼酸盐配合物在仿生催化领域受到的广泛关注,归纳总结了部分聚吡唑硼酸盐及其钒化合物,并初步探讨了其在合成、结构和性质方面的研究进展以及在医学领域的应用前景.     

Mechanism of Multipeaks Feature forVanadium titanium containing Magnetite in Smelting Reduction

The mechanism of multipeaks of reduction rate for vanadium titanium containing magnetite in the process of smelting reduction has been studied.The structure feature of vanadium titanium containing magnetite and changing character of slag structure as well as the kinetic feature of vanadium titanium containing magnetite in smelting reduction process were also analysed in this paper.