Effects of La~(3+)on H~+ Transmembrane Gradient and Membrane Potential in Rice Seedling Roots

Ｔｈｅｒｅａｒｅｌｏｔｓｏｆｓｔｕｄｉｅｓｉｎｔｈｅｆｉｅｌｄｓｏｆａ ｇｒｉｃｕｌｔｕｒａｌａｎｄｍｅｄｉｃａｌａｐｐｌｉｃａｔｉｏｎｓｏｆｒａｒｅｅａｒｔｈｓ[1,2 ] .ＴｈｅｒｅｓｕｌｔｓｆｒｏｍＣｈｉｎａｓｕｇｇｅｓｔｅｄｔｈａｔｓｕｐｐｌｙｉｎｇｒａｒｅｅａｒｔｈｓｍｉｇｈｔｈａｖｅｂｅｎｅｆｉｃｉａｌｅｆｆｅｃｔｓｏｎｐｌａｎｔｇｒｏｗｔｈａｎｄｃｒｏｐｐｒｏｄｕｃｔｓｑｕａｌ ｉｔｙ[3 ] .Ｓｏｍｅｒｅｓｅａｒｃｈｅｒｓｄｅｍｏｎｓｔｒａｔｅｄｔｈａｔｒａｒｅｅａｒｔｈｓｃａｎｎｏｔｅｎｔ…     

Effects of Rare Earth on Oxidative Damage and Redox System of Wheat Seedling Leaves under Water Stress

The leaf is the most sensitive site in plant underwater stress . With lengthening in duration of waterstress ,cell membrane of leaf will be damaged .Dhind-sa et al[1]found that when drought tolerant moss lostwater slowly , the activities of SOD and CAT de…     

Effects of Lanthanum on Root Growth and Senescence of GF43 （ Prunus domestica ） Plantlet in Vitro

The effect and the action mechanism of lanthanum on GF43 plantlet in vitro were studied. The results of experiments show that root growth rate and dry weight of GF43 by LaCI3 treatments increase. The activities of antioxidant enzymes in root system such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) apparently enhance. Moreover O^-2 and malond ialdehyde (MDA) contents and cell membrane permeability of GF43 are decreased by LaC13. The relatively stable membrane structure of cell could also be maintained and the root ageing of GF43 plantlet in vitro delays.     

Effects of Lanthanum on Redox Systems in Plasma Membranes of Casuarina equisetifolia Seedlings Under Acid Rain Stress

Theplasmamembraneisapenetrablebarrier ,whichcancontroltheexchangeofsubstancesacrossmembranesincells ,andalsoistheintermediumandreceptorofenergyorinformationtransferencebetweencellsandenvironment.Theplasmamembraneredoxsystem(PMRS)meanstheelectrontransferchainsonplasmamembrane .Owingtohavethepossibilityofejectingprotons ,energizingplasmamembraneandhavingthefunctionofacceleratingtransportationofsoluteacrossmembrane ,theplasmamembraneredoxsystemswerepaidmuchattentionto[1] .Acidrainisoneofthemost…     

Resistance of LaCl3 to Oxidative Stress Induced by 2, 4-Dichlorophenoxy

Inrecentyears,moreandmoreresearcheshave shownthatrareearthelementshaveeffectsonthere sistibilityofplantstoadverseenvironments[1,2].Di atloffetal.[3]suggestthatlowlevelofLa3 helps plantstowithstanddroughtstressbypromotingroot growth.StudiesbyChenetal.[4]i…     

微波消解-电感耦合等离子体原子发射光谱法测定钨基硬质合金中钴镍铁铌钽钒铬

以硝酸和磷酸(V （HNO₃）∶V（H₃PO₄）=5∶1)作为消解试剂,采取高压密闭微波加热方法对钨钴或钨镍类钨基硬质合金样品进行消解,消解液用水定容后直接以电感耦合等离子体原子发射光谱法(ICP-AES)测定0.005%～10% Co、Ni和0.005%～1% Fe、Nb、Ta、V、Cr、Mo的含量。考察了消解试剂中的硝酸和磷酸量对试样消解的影响以及微波控制参数等最佳消解条件,建立了微波消解－无机试剂络合基体钨的样品消解方法,从而避免了因钨酸沉淀析出而导致部分待测元素损失和使用有机络合剂对光谱测定的干扰影响。实验结果表明：采用以5 min升温至130 ℃并保持5 min,再以5 min升温至190 ℃并保持15 min的消解程序,样品的消解效果较好。试验通过优选元素分析谱线,基体匹配和同步背景校正法消除了高钨基体的影响和光谱干扰,确保了方法的可靠性。背景等效浓度值从5 μg/L (Nb)至18 μg/L(Fe),元素检出限从4 μg/L (Nb)至13 μg/L (Fe)。方法用于钨基硬质合金样品中上述合金或杂质元素的测定,RSD<3%,加标回收率在97%～104%之间,测定结果与国家标准方法检测结果对照一致。     

Electrochemical Preparation of La—Fe Alloy Films in Dimethylsulfoxide（DMSO）

Ｒａｒｅｅａｒｔｈｓａｎｄｔｈｅｉｒａｌｌｏｙｓｈａｖｅｓｐｅｃｉｆｉｃｐｒｏｐｅｒｔｉｅｓ ,ｓｕｃｈａｓｍａｇｎｅｔｉｃ ,ｏｐｔｉｃａｌ,ｅｌｅｃｔｒｉｃａｎｄｈｙｄｒｏｇｅｎｓｔｏｒａｇｅ .Ｔｈｅｙｈａｖｅｂｅｅｎｗｉｄｅｌｙａｐｐｌｉｅｄｔｏｖａｒｉｏｕｓｆｕｎｃｔｉｏｎａｌｍａｔｅｒｉａｌｓ .ＴｈｅＬａ Ｆｅａｌｌｏｙｓｈａｖｅｂｅｅｎａｐｐｌｉｅｄａｓｍａｇｎｅｔｉｃｍａｔｅｒｉａｌｓ .Ｓｉｎｃｅｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓａｒｅｖｅｒｙａｃｔｉｖｅ,ｉｔｉｓｖｅｒｙｄｉｆｆｉｃｕ…     

Effect of Lanthanum on Expression of Recombinant Allophycocyanin Gene in Pichia Pastoris

The methylotrophic yeast ,Pichia pastorishasbeen developed to be an outstanding host for the pro-duction of foreign proteins since its alcohol oxidasepromoter was isolated and cloned ,and its transforma-tion was first reported in 1985[1 ,2].This organismh…     

Effects of LaCl3 on the growth and photosynthetic characteristics of Fny-infected tobacco seedlings

Plant growth, gas exchange characteristics, chlorophyll fluorescence, disease index, and disease prevention efficiency of LaCl3 in tobacco (Nicotiana glutinosa) plants infected by Fny-CMV (fny stain of cucumber mosaic virus) strain were determined. Leaf area, chloro-phyll and carotenoid contents, maximum photosynthesis rate, apparent quantum yield, and carboxylation efficiency dramatically decreased after 5 weeks post inoculation. The plants infected by Fny-CMV only presented much severer symptom than those infected in the presence of appropriate concentration of LaCl3. ETR (apparent rate of photosynthetic electron transport), NPQ (nonphotochemical quenching), qP (coef-ficient of photochemical quenching), and yield (II) in infected tobacco plants obviously reduced in higher light intensity after 5 weeks post inoculation. And these fluorescence parameters in Fny-infected plants obviously reduced compared with those in the plants infected by Fny in the presence of LaCl3. Together with the growth status and disease index, it revealed that exogenously appropriate concentration of LaCl3 could significantly alleviate the damage of tobacco seedlings caused by Fny-CMV.     

Strategies to improve the nutritive value of rice bran in poultry diets. III. The addition of inorganic phosphorus and a phytase to duck diets

1. In the first of 2 experiments ducklings grown from 2 to 19 d were given diets with 0, 200 or 400 g rice bran, with or without a phytase and with 1 or 3 g inorganic phosphorus (Pi) per kg for rice bran-based diets only. In the 2nd experiment rice bran concentrations were 0, 300 or 600 g rice bran per kg with or without a phytase and 1 g Pi/kg. Ducks were grown from 19 to 40 d of age. 2. In experiment 1, a response to phytase was observed for weight gain and food intake on most diets except those with 200 g rice bran (3 g Pi) and 4.00 g rice bran (1 g P)i/kg. Main effects showed that 400 g rice bran depressed growth rate and food conversion ratio (FCR); increasing Pi depressed food intake, while food phytase increased food intake and growth rate over 2 to 19 d. There were several interactions. Dry matter and P retention were reduced but N digestibility improved when rice bran was increased from 200 g to 400 g/kg at 2 to 10 d of age; apparent metabolisable energy (AME) and calcium retentions were improved, similar results being seen at 10 to 19 d of age. Calcium and P retentions increased with the addition of food phytase and, at 10 to 19 d of age, phytase increased dry matter digestibility. Increasing Pi improved calcium and P retention, but only at 2 to 10 d of age. 3. Tibia ash (g or g/kg) content of bone was lowest on the diet without rice bran and without phytase; Pi concentration had no effect but phytase increased tibia ash on diets with 0 and 200 g rice bran and 1 g Pi/kg. Retention of several minerals in tibia ash declined at the highest rice bran inclusion rate; Pi level and phytase both increased Mg retention. 4. In experiment 2, food intake and growth rate of ducks, but not FCR, declined as rice bran inclusion increased from 0 to 600 g/kg. Phytase improved growth rate but not food intake and FCR on all 3 diets. Dry matter digestibility declined with increasing rice bran inclusion, but AME increased; retention of P and Mg declined but those of Ca and Fe increased. Phytase improved dry matter digestibility and retention of N and P. AME also increased but this was only on diets with 0 and 600 g rice bran/kg. There were reductions of 8% and 10% in P excreted in experiments 1 and 2 respectively when food phytase was added. 5. Tibia ash declined with increasing dietary inclusion of rice bran. Zn and Mn in ash tended to decline and Mg to increase; Ca and P showed no change in concentration in tibia ash. Again, phytase increased tibia ash content in bone. 6. It was concluded that there were a number of unexpected benefits from adding a food phytase to these diets, which resulted in improved nutrient yield and bird performance, although several of the diets appeared to be adequate in available P.     

Influence of the physical structure of phospholipid membranes on peroxidation induced by Fe2+ ions

Kinetics of free radical lipid peroxidation, induced by Fe2+ in presence of ascorbic acid, was studied in phospholipid membranes. The maximal rate of peroxidative oxidation was observed at 2.5 muM concentration of Fe2+, in this case a half of the maximal amount of peroxidative oxidation products was formed within 20-30 min at 20 degrees and at 200 muM concentration of ascorbic acid. The rate of peroxidative oxidation depended on addition of substances modifying the membrane structure (linoleic acid, cetyl trimethylammonium, Tween-60, derivatives of phenothiazol). Charge of the membrane surface was shown to have a distinct effect on the peroxidative oxidation. Loosening of membranes by non-ion detergent (Tween-60) increased the rate of the process, whereas the increase of the membranes rigidity by cholesterol did not cause any effect. Uneffectiveness of cholesterol is discussed with relation to diffusion of radicals, participating in peroxidative oxidation, from depth of the membrane to its surface and in the opposite direction.     

阻抑溴酸钾氧化乙基橙褪色动力学极谱法测定痕量铁

摘要：在稀硫酸介质中,痕量铁对溴酸钾氧化乙基橙褪色反应有很强的抑制作用。基于乙基橙能在氨性介质中在电极上于-060 V处产生灵敏的极谱吸附波,利用极谱法监测阻抑反应过程中乙基橙浓度的变化,建立了铁-溴酸钾-乙基橙体系阻抑动力学极谱法测定痕量铁的新方法。详细讨论了硫酸用量、溴酸钾用量、乙基橙用量及反应温度和时间等条件对铁测定的影响。在选定最佳条件下,方法的线性范围为0004 8~04 μg/mL,检出限为0002 1 μg/mL。用于水样中铁的测定,结果与火焰原子吸收光谱法测定值一致,相对标准偏差（RSD）为12%～29%。     

Molecular modelling study of the netropsin complexation with a nucleic acid triple helix

The relationship between lipid peroxidation and uptake of transferrin- free iron, Fe(II), by reticulocytes in an experimental system for studying membrane transport of Fe(II) was investigated by using free radical scavengers: BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), superoxide dismutase, alpha-tocopherol, propyl gallate and DPPD (N,N-diphenyl-1,4-phenylenediamine), and producers: t-butyl hydroperoxide, cumene hydroperoxide, H2O2 and aluminium carbonate. Measurements were made of MDA (malondialdehyde) and the rate of Fe(II) uptake from a sucrose solution buffered at pH 6.5 by Pipes. Most scavengers and producers used could increase or decrease only slightly the rate of Fe(II) uptake and some of them had no effect on Fe(II) uptake and MDA could not be detected at iron concentration of lower than 10 microM and incubation time of 20 min. At iron concentration of higher than 100 microM and incubation time of 4 h, there was the production of MDA which increased with the increment of iron concentration of incubation medium and BHT could inhibit the production of MDA. In addition, no difference was found in the rates of Fe(II) uptake in three experimental groups whose incubation medium was buffered by Pipes, Mops and Mes respectively. The results suggested that iron could induce free radical reaction under experimental conditions, especially at high concentration of iron and longer incubation time; however, at low concentration of iron (<10 microM) and the usual incubation time (20 min) free radical reaction was very slight and the extent of the reaction was not enough to damage the integrity and function of the membrane of reticulocytes, and that Fe(II) uptake by reticulocytes was not the result of free radical reaction and lipid peroxidation. It was therefore concluded that iron could not initiate its own membrane transport in rabbit reticulocytes by free radical reaction and lipid peroxidation and that the experimental system we used for studying membrane transport of Fe(II) is valid.     

碳纤维负载零价铁的制备及其去除水溶液中的六价铬

以碳纤维作为载体,采用电沉积法制备碳纤维负载零价铁(PCF-ZVI),利用扫描电镜、能谱仪及X射线衍射仪对其进行了表征,并考察了其对水溶液中Cr(VI)的去除效果.实验结果表明:碳纤维负载零价铁对水溶液中的Cr(VI)具有很好的去除效果.当铁碳质量比为2∶1,投加量(以Fe0计)为2 g·L-1,Cr(VI)初始质量浓度为20 mg·L-1,pH值为5,反应时间40min后,Cr(VI)的去除率可达99.96%,碳纤维上负载的零价铁对Cr(VI)的还原过程为准一级动力学,并且还原速率与反应温度的关系符合Arrhenius定律,反应活化能为20.683 k J·mol-1.      

电感耦合等离子体原子发射光谱法测定高纯石墨中9种元素

高纯石墨作为优异的功能材料被广泛应用于国防和航空航天等产业,其对痕量杂质元素含量的要求也逐年提高,目前所用的测试方法检出限都较高,已不能满足日益增长的测试需求。实验将1 g高纯石墨样品置于1 100 ℃马弗炉中灰化至完全;取出冷却,加入3 g助熔剂(m(H₃BO₃)∶m(Na₂CO₃)=1∶2),再次放入马弗炉中,在1 100 ℃下加热熔融40 min至熔液澄清;取出冷却,使用盐酸(1+1)溶解盐类。采用Al 396.152 nm、Ca 396.847 nm、Cr 267.716 nm、Cu 324.754 nm、Fe 238.204 nm、Mg 279.553 nm、Ni 231.604 nm、Si 251.612 nm、Zn 213.856 nm作为分析线,建立了使用电感耦合等离子体原子发射光谱法(ICP-AES)测定高纯石墨中铝、钙、铬、铜、铁、镁、镍、硅和锌等9种杂质元素的方法。结果表明,铝、钙、铬、铜、铁、镁、镍、硅和锌的质量浓度在0.50～500 μg/mL范围内与发射强度呈线性,校准曲线的线性相关系数均大于0.999 5;方法中各元素的检出限为0.037～0.87 μg/g。将方法应用于高纯石墨样品中9种杂质元素的测定,测定结果与电感耦合等离子体质谱法的测定结果相吻合,相对标准偏差(RSD,n=7)均小于6.0%,回收率为93%～108%。     

Mechanism of Effect of Lanthanum Nitrate on Vigor of Aged Rice Seeds

Ｓｅｅｄｓｅａｒｌｙｄｅｇｅｎｅｒａｔｅｄｏｒａｇｅｄｂｙｕｎ ｓｕｉｔａｂｌｅｃｕｌｔｉｖａｔｉｏｎｏｒｕｎｓｔｏｒａｇｅｔｅｃｈｎｉｑｕｅｓｍａｙｒｅｓｕｌｔｉｎｄｅｃｒｅａｓｉｎｇｏｆｓｅｅｄｖｉｇｏｒａｎｄｏｆｔｈｅｃｒｏｐｓｏｕｔｐｕｔ,ｅｓｐｅｃｉａｌｌｙｆｏｒｒｉｃｅ.Ｒａｒｅｅａｒｔｈｓａｃｃｅｌｅｒａｔｅｔｈｅｇｅｒｍｉｎａｔｉｏｎａｎｄｇｒｏｗｔｈｏｆｔｈｅｃｒｏｐｓ ,ｓｕｃｈａｓｒｉｃｅ ,ｗｈｅａｔ,ｂａｒｌｅｙ ,ｖｅｇ ｅｔａｂｌｅｓａｎｄｏｉｌｐｌａｎｔｓ[1～ 3] .Ｔｈｅｓｔ…     

The effect of long-term calcium supplementation on indices of iron, zinc and magnesium status in lactating Gambian women

The effect of long-term supplementation with CaCO3 on indices of Fe, Zn and Mg status was investigated in a randomized, double-blind intervention study of sixty lactating Gambian women. The supplement contained 1000 mg Ca and was consumed between meals 5 d/week, for 1 year starting 1.5 weeks postpartum. Compliance was 100%. Plasma ferritin concentration, plasma Zn concentration and urinary Mg output were measured before, during and after supplementation at 1.5, 13, 52 and 78 weeks postpartum. No significant differences in mineral status were observed at any time between women in the supplement and placebo groups. Analysis of the longitudinal data series showed that plasma ferritin and Mg excretion were characteristic of the individual (P < 0.001). Within individuals, ferritin concentration was higher at 1.5 weeks postpartum than later in lactation (P = 0.002). Plasma Zn concentration was lower at 1.5 weeks postpartum than at other times (P < 0.001), an effect which disappeared after albumin correction. Low plasma concentrations of ferritin and Zn indicated that the Gambian women were at high risk of Fe and Zn deficiency. Measurements of alpha 1-antichymotrypsin suggested that the results were not confounded by acute-phase responses. The results of the present study indicate that 1000 mg Ca as CaCO3 given between meals does not deleteriously affect plasma ferritin and Zn concentrations or urinary Mg excretion in women who are at risk of Fe and Zn deficiency.     

Alzheimer's peptides A beta 1-40 and A beta 1-28 inhibit the plasma cholesterol esterification rate

The amyloid fibrils of Alzheimer's disease and Down's syndrome amyloid deposits are composed mainly of aggregated amyloid beta protein (A beta) which also exists in a soluble form. It has been shown that both Alzheimer's disease and Down's syndrome share another common feature: the decrease in plasma cholesterol esterification in affected individuals. In the present work the effect of synthetic peptides A beta 1-40 and A beta 1-28 on normal human plasma cholesterol esterification rate was studied. Both peptides at a concentration of 1 ng/ml inhibited plasma cholesterol esterification rate to 40-50 % of control value. Statistical analysis showed no differences in the effect of A beta 1-40 and A beta 1-28 on the inhibition, suggesting the importance of A beta sequence 1-28 for this effect.     

化学腐蚀后的表面状态对硅片Fe沾污的影响

利用不同的酸腐蚀和碱腐蚀条件对硅片进行了腐蚀,分析了腐蚀后的硅片表面状态对Fe沾污的影响.实验结果表明,不同酸腐蚀条件的硅片经过以HF酸结尾的改进型RCA(Radio Corporation of America)清洗法清洗后,表面疏水性增强,相对不易附着Fe离子,而当酸腐蚀硅片表面经过SC-1溶液处理后,表面亲水性增...     

Effect of lanthanide ions on the phase behavior of dipalmitoylphosphatidylcholine multilamellar liposomes

The effect of lanthanide ions (Ln3+) and their coordination compounds of diethylenetriamine pentaacetic acid (DTPA) on the phase behavior of dipalmitoylphosphatidylcholine (DPPC) multi-lamellar liposomes has been studied by differential scanning calorimetry (DSC), Raman spectroscopy, and freeze-fracture electron microscopic techniques. The displacement of Ca2+ binding on DPPC liposomes by lanthanide ions was also studied. The results show that the binding degree of four kinds of chloride salts with DPPC liposomes is: YbCl3 > GdCl3 > LaCl3 > CaCl2. Lanthanide ions increase the phase transition temperature of DPPC liposomes and decrease the membrane fluidity. Freeze-fracture electron microscopic results show that La3+ enhances the order of DPPC membrane. The effect of coordination compounds of lanthanides with DTPA on the phase behavior of DPPC liposomes is smaller than that of their chlorides. La3+, Gd3+, and Yb3+, can displace Ca2+ binding on DPPC liposomes, but there coordination compounds of DTPA can hardly displace Ca2+. Raman spectroscopic results show that a very slight effect in lateral packing order of DPPC liposomes was observed at various concentrations of lanthanides.