镉锌复合污染对龙葵苗期生长和镉锌累积特性的影响

采用营养液培养法研究了苗期龙葵(Solanumnigrum L.)对镉锌复合污染的反应及其对镉锌的吸收和积累特性.结果表明:(1)高浓度镉(200μmol·L-1)、锌(500μmol·L-1)胁迫使苗期龙葵植株生长受到严重抑制,但低浓度镉锌复合处理的部分植株生物量甚至超过了对照.(2)添加锌对苗期龙葵地上部镉积累有显著的影响(P<0.05);当锌浓度为100μmol·L-1时,镉积累量达到峰值,其中的100Cd/100Znμmol·L-1处理组合的镉积累量为所有处理中的最大值(地上部积累量高达171.31μg·plant-1);当锌浓度增加到500μmol·L-1时,植株体内镉积累量则呈现下降趋势.(3)添加镉对苗期龙葵地上部锌积累也有显著的影响(P<0.05);当镉浓度达50μmol·L-1时,根、茎、叶中锌积累量均达到最高值;当镉浓度为200μmol·L-1时,各处理单株地上部锌积累量最低.(4)从植株整体的镉、锌积累量来看,苗期龙葵地上部镉积累量最高达根系的14.67倍,而其锌积累量最高达根系的13.59倍.研究发现,龙葵幼苗根系、茎和叶中镉、锌含量随营养液中镉、锌浓度的增加而显著增加(P<0.05);添加锌在一定程度上缓解了镉对苗期龙葵的毒害效应,低浓度锌还可以提高植株对镉的吸收和积累;添加镉在一定程度上增强了植株对锌的耐受性和吸收富集能力;植株地上部的镉、锌积累量明显高于根系.     

温度和无机碳浓度对龙须眼子菜（Potamogeton pectinatus）碳同位素分馏的影响

温度和无机碳浓度是沉水植物碳同位素分馏的重要影响因素.通过在16、19、22、25、28、31℃ 6个温度条件和溶解无机碳浓度(DIC)为0.0001mol·L-1和0.0001mol·L-1两种条件下培养沉水植物--龙须眼子菜(Potamogeton pectinatus),获得了不同条件下生长的龙须眼子菜植物样品,随后进行了定量和碳同位素组成(δ13CP)分析.分析结果表明,随生长温度的升高,龙须眼子菜碳δ13CP均升高,具有明显的温度相关性(R2＞0.90).在DIC浓度为0.0001mol·L-1时,随着生长温度的升高, δ13CP从-14.83‰增加至-13.47‰;而在DIC浓度为0.001mol·L-1时, δ13CP从-18.56‰增加至-15.15‰.同一生长温度条件下, DIC浓度对δ13CP也有明显影响, δ13CP随DIC浓度增高而降低.在不同生长温度条件下, DIC浓度对δ13CP的影响大小随生长温度的增高而降低,在温度为16℃时,两个DIC浓度下的δ13CP相差3.73‰;而在温度为31℃时,这一差值减少为1.68‰.同时,通过建模进行计算,获得了不同温度下龙须眼子菜(P. pectinatus)碳同位素分馏与初始DIC浓度的关系,并对有关的参数的意义进行了探讨.     

流沙湾海草床重金属富集特征

海草床是一种重要的海洋湿地生态系统,首次研究了流沙湾海草床重金属(铜、铅、镉、锌)的富集特征,并评价其潜在生态危害.研究表明:水体和沉积物环境中的重金属含量很低,潜在生态危害轻微,但是海草床大型底栖生物(绿藻、海草、双壳类和腹足类)对这4种重金属具有富集作用,其中对镉的富集最显著.绿藻对铜、铅和锌的富集效应明显大于海草,腹足类对铜、铅和锌的富集效应明显大于双壳类;而对镉的富集效应,情况正好相反.双壳类生物体内铅和镉含量普遍超一类标准,超标程度较高.     

海洋浮游藻类无机碳利用机理的研究

为了认识海洋浮游藻类在碳充足和碳受限条件下对水体中溶解无机碳 (DIC)的利用方式与可能机理 ,对 13种海洋浮游藻类在不同pH和CO2 浓度及不同DIC条件下细胞外碳酸酐酶 (CA)的活性进行了分析测定。结果显示 :13种藻中 ,只有Amphidiniumcarterae和Prorocentrumminimum在碳充足条件下具细胞外CA活性。Melosirasp .、Phaeodactylumtricornutum、Skeletonemacostatum、Thalassiosirarotula、Emilianiahuxleyi和Pleurochrysiscarterae则在碳受限条件下才具细胞外CA活性。Chaetoceroscompressus、Glenodiniumfoliaceum、Coccolithuspelagicus、Gephrocapsaoceanica和Heterosigmaakashiwo即使在碳受限条件下也未检测到细胞外CA活性。应用封闭系统中pH漂移技术和阴离子交换抑制剂 4′4′ diisothiocyanatostilbene_2 ,2_disulfonicacid (DIDS)等的研究表明 ,Coc.pelagicus和G .oceanica可通过阴离子交换机制进行HCO-3 的直接利用。H .akashiwo没有潜在的HCO-3 直接利用或细胞外CA催化的HCO-3 利用     

供锌水平对寒地春玉米幼苗抗氧化酶活性等生理特性的影响

本试验选用不同耐锌玉米品种,采用营养液水培,研究不同锌浓度对玉米株高、地上部干重、根干重及SOD、POD、TTC、硝酸还原酶活性、细胞膜透性的影响。结果表明：耐锌品种‘牡单九’的适宜锌浓度为0．1μmol．L-1,锌敏感品种‘四单十九’的适宜锌浓度为1μmol．L-1。不同锌浓度对玉米生长的影响主要表现在地上部,而对地下部生长影响较小。随着锌浓度的升高,SOD和POD的活性增大。当锌浓度为0．1μmol．L-1时根系活力最高,在锌浓度大于1μmol．L-1时,根系活力下降较明显。硝酸还原酶活性在锌浓度大于0．01μmol．L-1时,随着锌浓度升高而降低。在锌浓度为1μmol．L-1时,细胞膜透性最小,低锌和高锌胁迫下细胞膜透性都有不同程度的增加。     

CO2浓度升高对不同品种水稻镉吸收和根形态的影响

为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5～200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一.     

L929细胞镉中毒模型的建立

以L929细胞为研究对象,建立镉中毒体外模型,研究镉中毒对成纤维细胞生长发育的影响.本研究使用含有终浓度为100、50、25和5μmol·L-1氯化镉的DMEM培养基培养L929细胞,培养后0、6、12、24、36、48 h时分别观察细胞形态学变化,并应用MTT(四甲基偶氮唑盐)比色法来测定细胞的活性,研究结果表明,与正常组比较,当镉浓度大于50 μmol·L-1时,细胞形态损伤严重,细胞活性明显下降(p＜0.01);当镉浓度为5 μmol·L-1时,细胞未出现明显损伤,细胞活性无统计学差异(p＞0.05);时间效应观察结果显示,当镉作用36 h以上,细胞出现严重损伤,较多细胞悬浮于细胞培养基中,细胞活性明显下降(p＜0.01).结果表明,镉的终浓度为25 μmol·L-1,与L929细胞共同作用24 h为建立镉中毒体外模型的最佳条件.     

不同CO2浓度下培养的蛋白核小球藻细胞结构的变化

大气 CO2 浓度升高已成为全球关注的一大热点问题 ,CO2 浓度升高对陆生植物影响已有广泛的研究[1] 。但水生植物由于水体中无机碳主要以CO2 -3 、HCO-3 和 CO2 的形式存在 ,所以对大气 CO2浓度升高的响应较为复杂。已有的有关 CO2 浓度与藻类关系的研究主要侧重于高浓度 CO2 对其生理学特性的影响 ,如 :当单细胞绿藻生活在高浓度 CO2( 5 % )的环境中时 ,细胞对 CO2 的亲和力明显降低 ,CO2 补偿点升高 ,碳酸酐酶的活性降低 ,细胞亚显微结构也伴随着明显变化 [2 ,3 ]。但以上的研究均采用很高的 CO2 浓度 (一般为 5 % ) ,而在现实的…     

单一与复合污染条件下两种敏感性植物对Cd、Zn、Pb的吸收效应

为了进一步研究镉、锌、铅 3种重金属元素间的相互作用以及对植物吸收重金属能力的影响 ,在模拟单一重金属污染试验研究的基础上 ,采用正交回归设计方案 ,研究了 Cd、Zn、Pb复合污染情况下紫花苜蓿和披碱草两种敏感性植物对 3种重金属的吸收效应。结果表明 ,在单一污染条件下 ,镉元素对紫花苜蓿生长的影响大于锌、铅 ,铅元素对披碱草生长的影响大于锌、镉 ;紫花苜蓿对于镉的吸收累积显著高于披碱草 ,植物内镉元素浓度最高达到 1 0 88.5 mg/kg,而披碱草对于铅元素的吸收则高于紫花苜蓿 ,植物内铅元素浓度最高达到 1 3 4 5 .5 mg/kg。在复合污染条件下 ,两种植物对铅、锌和铅、镉的吸收在不同浓度范围内分别存在存在着协同效应和拮抗效应 ;同时两种植物对锌、镉元素在实验涉及浓度范围内都存在着拮抗效应。这对于深入研究复合污染条件下重金属的土壤环境化学行为 ,对植物的综合毒性以及不同植物对重金属的吸收累积效应等 ,具有一定的参考意义     

龙胜县丘陵山区土壤与罗汉果重金属含量及潜在生态危害评价——以宝赠村为例

桂林市龙胜县作为罗汉果的三大主产区之一,种植区土壤重金属含量及罗汉果质量影响到该区罗汉果产业的健康发展。为探索龙胜县丘陵山区典型贫困村罗汉果园的安全性,该文研究了宝赠村典型罗汉果园土壤及罗汉果果实中砷、铜、锌、铅、镉、铬、汞7种重金属含量,并采用Hankanson指数法分析了其潜在生态风险。结果表明:(1)龙胜丘陵山区罗汉果园土壤(0~10 cm,10~20 cm)重金属含量均达到国家农业用地土壤筛选值标准(GB15618-2018),其中0~10 cm土壤中砷、铜、锌、铅、镉、铬、汞的含量分别为3.67、18.00、58.39、17.01、0.10、28.57、0.08 mg·kg^-1,10~20 cm土壤中砷、铜、锌、铅、镉、铬、汞的含量分别为1.93、12.56、21.47、10.51、0.04、17.09、0.02 mg·kg^-1。(2)在0~10 cm和10~20 cm土层中,重金属的生态风险状况总体上处于轻微生态风险等级,综合生态风险指数分别为105.29和38.96;0~10 cm土层不同重金属潜在的生态风险顺序为汞>镉>铅>铜>砷>锌>铬,汞、镉的生态风险分别为50.16、42.05,在总重金属风险中贡献率分别占所有重金属的47.6%和39.9%,已达中等生态风险等级;在10~20 cm土层中,7种重金属的生态风险大小关系为镉>汞>铜>铅>砷>铬>锌。(3)研究区罗汉果果实中砷、铜、锌、铅、镉、铬、汞的含量分别为0.00024、0.273、1.10、0.0016、0.00013、0.00013、0.00012 mg·kg^-1,其生态风险状况均处于轻微风险等级,7种重金属的生态风险顺序为汞>铜>镉>锌>铅>砷>铬,综合生态风险指数为0.21193,几乎不存在生态风险。因此,在龙胜县丘陵山区典型贫困村——乐江镇宝赠村推广种植的罗汉果达到了安全质量标准。     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three reconstituted reference serum samples by comparison with other methods and by the standard addition procedure. The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision, and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest in the environment, the relatively delicate sample handling, and the high cost of the equipment.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Crystal structure, detonation performance, and thermal stability of a new polynitro cage compound: 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptacyclo [5.5.1.13, 11. 15, 9] pentadecane

A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues and body fluids. A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America, Australia, and New Zealand. This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world. It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different countries reflected some interesting associations for elements, such as Mn and Zn. Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as Cu, Fe, and Zn were not available. In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions, which sadly lack data of any kind at present.     

Relations of the Al,B, Ba,Br, Ca,Cl, Cu,Fe, K,Li, Mg,Mn, Na,P, S,Si, Sr,and Zn mass fractions to morphometric parameters in pediatric and nonhyperplastic young adult prostate glands

The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Monovalent Cation Permeation through the Connexin40 Gap Junction Channel : Cs,Rb, K,Na, Li,TEA, TMA,TBA, and Effects of Anions Br,Cl, F,Acetate, Aspartate,Glutamate, and NO3

The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γ_j in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γ_j are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO₃ (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li⁺ are: Cs⁺ (1.38), Rb⁺ (1.32), K⁺ (1.31), Na⁺ (1.16), TMA⁺ (0.53), TEA⁺ (0.45), TBA⁺ (0.03), Cl⁻ (0.19), glutamate⁻ (0.04), and NO₃− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.     

Caprine blood groups. 2. The C,G, H,I, J,K, L,N, and Q systems

Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles,C ¹²,C ²⁵, andC ⁻. A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G ^10.19.20,G ^10.19,G ^10.20,G ¹⁰,G ¹⁹,G ²⁰) and a recessive allele (G ⁻). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively. This work was supported by a grant from the Australian Stud Book, Alison Road, Randwick, New South Wales 2031, Australia.