Determination of elements in bovine tissues by instrumental neutron activation analysis

Instrumental neutron activation analysis was carried out to obtain the normal concentration of trace elements in bovine tissues (heart, liver, kidney, spleen, lymph nodes) and serum. Concentrations of 17 elements were determined. In this paper, concentrations of Al, Br, Cs, In and Rb are given and correlations of concentrations are discussed between Cl and Br and between K and Cs or Rb. Significant positive correlations have been found between Cl and Br concentrations in all tissues, between K and Cs concentrations in tissues excluding kidney, and between K and Rb concentrations in tissues excluding liver.     

Preliminary study of trace elements in human brain tumor tissues by instrumental neutron activation analysis

Elemental profiles of brain tumor tissues from 15 patients of astrocytomas (grade I–III) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by instrumental neutron activation analysis. The SLOWPOKE reactor with a thermal neutron flux of 8·10¹¹n·cm^–2·s^–1 and swimming pool type reactor with a thermal neutron flux of 1·10¹³n·cm^–2·s^–1 were used for short and long irradiation of samples, respectively. Spectrophotometry was only used for analyzing phosphorus. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg, S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The reliability of methods has been checked by analyzing biological standard reference materials horse kidney (IAEA H-8) and bovine liver (NBS SRM 1577a). The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Se, Mn, Br and Sc were significantly higher in tumor tissues (P<0.01) and concentrations of Rb, K and P were lower, while no differences for contents of Mg, S, Cr, Hg, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.     

Trace elements in sickle cell disease

Instrumental Neutron Activation Analysis (INAA) and Proton-Induced X-ray Emission (PIXE) analysis (employed as a complementary technique) have been used to determine the concentration of 11 elements in blood samples and its components erythrocytes and plasma obtained, from three groups of subjects in Nigeria viz: sickle cell anaemia (SCA) subjects, subjects with sickle cell trait and normal control subjects. The results suggest that SCA subjects have significantly higher concentrations of Na, Cl, Ca and Cu in their whole blood and erythrocytes and a higher concentration, of Cl and Cu in their plasma relative to the control subjects. Furthermore, a significantly lower concentration of K, Fe, Zn, Se, Br and Rb were found in the whole blood and erythrocytes of the SCA subjects as compared to the controls while the concentration of K and Fe in the plasma of the SCA subjects were however, found to be significantly higher than that of the control group. The study also shows that there was no significant differences between the concentration of these 11 elements in the group with sickle cell trait and the normal control group.     

Br2+Cl2=2BrCl反应机理的理论和实验研究

用(U)MP2方法, 取6-311G*基组, 研究了反应Br2+Cl2=2BrCl的机理, 求得四中心和三中心的过渡态, 通过比较反应通道的活化能的大小, 得到如下结论: 双分子基元反应的最小活化能小于Cl2和Br2的离解能, 在没有光引发的条件下, 标题反应将以分子与分子作用形式完成; 若有光引发, Br2或Cl2先解离成原子, 再经过Br原子与Cl2反应或Cl原子与Br2反应, 能较快完成标题反应. 分别测定了光照和避光两种条件下的反应体系在412 nm处吸光度的变化, 证实了理论研究的结果.     

Analysis of elements in human blood of patients with chronic kidney disease using neutron activation analysis

Neutron activation analysis has been used to determine Br, Ca, Cl, K, Mg and Na concentrations in whole blood of patients with chronic kidney disease (CKD) as well as in whole blood of normal individuals (control group). The dependence of the elements concentration in function of sex, age, time and type of treatment were investigated. The similarities and differences between healthy individuals and CKD are discussed.     

Possibilities of Density Functional Theory in Standardless Quantitative Spectral Analysis

Density functional theory can be used in the quantitative analysis of substances by their IR spectra in cases when high precision is not necessary or certified reference samples are principally unavailable or are difficult to obtain. IR spectra of 30 complex organic molecules including different heteroatoms (Br, Cl, F, N, O) were calculated using the Gaussian98w program (6-31G) basis set. The calculated spectra were compared with experimental ones, and quantitative inverse spectral problems (calculation of concentrations) were solved for all of the molecules studied. It was shown that the found concentrations for the majority of the studied substances differ from their true concentrations by no more than 30%, which is acceptable, for example, for ecological monitoring.     

Subcellular distribution of Al, Cu, Mg, Mn and other elements in the human liver

The elemental concentrations and chemical species of Al, Br, Cl, Cu, K, Mg, Mn, Na and I in human liver and its subcellular fractions were studied by several biochemical techniques combined with neutron activation analysis. The highest concentrations of Al, Mg, and I were found in the nuclei, whereas those of Br, Cu, Cl, K, Mn and Na in the cytosol. About 20% of Br, half of Al and most of Cu (78.8%), Mg (65.9%) and Mn (80.6%) remained in the cellulose bags after dialysis of liver homogenate, which were suggested to be bound to macromolecules. K (100%) and more than 95% of Cl and Na were found to be in the dialyzates. Similar results were found in the fractions of nuclei, mitochondria, lysosome and microsome, respectively, after the same treatment. Further study was carried out to elucidate the elemental distribution in the cytosol by ethanol precipitation and by ammonium sulfate fractionation. The results suggested that several kinds of Cu-, Mn- and Mg-bound proteins existed in the cytosol of human liver cells. Received: 3 August 1998 / Revised: 22 September 1998 / Accepted: 26 September 1998     

INAA of cortical and trabecular bone samples from animals

Instrumental neutron activation analysis (INAA) was applied to determine Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Sr and Zn in bovine and porcine rib bones. Precise results were obtained in analyses of freeze-dried cortical and trabecular bones separately, and also of whole bone ashes. Cortical tissues presented higher concentrations of Ba, Ca, Mg, Mn, Na, P, Sr and Zn than those obtained in trabecular ones. Comparisons were also made between the results obtained for bovine and porcine rib bones. This revised version was published online in August 2006 with corrections to the Cover Date.     

Electronic structures and electron detachment energies of halogen substituted acetate anions, XCH2COO- (X=F,Cl,Br)

The electronic structures and the halogen inductive effects on the acetate anion were investigated in XCH2COO- (X=F,Cl,Br) by photoelectron spectroscopy (PES) and ab initio calculations. The PES spectra indicated that the electron binding energies increased in the order of FCl>Br. These systematic changes of detachment energy and IPs were explained by examining the charge redistributions upon detaching electrons.     

Cognitive impairment related changes in the elemental concentration in the brain of old rat

In order to evaluate the elemental concentration as a function of learning and memory deficiency, six different structures of the brain were analyzed by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). To evaluate the cognitive processes, the animals were tested in an adaptation of the Morris water maze. After the test, the animals were divided into two groups: cognitively healthy (control group) and cognitively impaired. The measurements were carried out at XRF beam line at Light Synchrotron Brazilian laboratory, Campinas, Brazil. The following elements were identified: Al, P, S, Cl, K, Ca, Ti, Cr, Fe, Cu, Zn, Br and Rb. K concentration was higher in all regions of the brain studied for control group than the cognitively impaired group. Moreover, the control group presented higher levels for P and Fe in the entorhinal cortex, in the temporal cortex (only P), in the hypothalamus and in the thalamus, than the cognitively impaired group. Br concentration in the animals which presented cognitive impairment was three times larger in the hypothalamus and thalamus, twice larger in temporal cortex and higher in visual cortex than the cognitively healthy group. Cu was more remarkable in the hippocampus and hypothalamus from the animals with cognitive impairment than the control group.We observed that the cognitively impaired group presented highest concentrations of Br and Cu in certain areas than the control group, on the other hand, this group presented highest levels of K for all brain areas studied.     

Kinetics of element profile pattern during life cycle stage of morning-glory

We present the kinetics of seven element profiles, macroscopic elements, Na, Mg, Cl, K and Ca, as well as Al and Br, in every tissue of morningglory (Ipomoea nil L. c.v. Murasaki), from seedling to flowering stage. Barriers for the elements were formed even in the same tissue during different growing phases. Most of Na and Al remained in root tissue, showing the first barrier to the upper part of the plant. During the juvenile phase, the tissues lower than cotyledon stored the elements, especially Ca and Mg. The barrier at cotyledon did not disappear completely until seed ripening stage, except for K. Generally, late developing stem showed lower accumulation of the elements, which seemed to regulate the inflow of Mg, Ca, Cl and Br into flowering tissue. The concentrations of K, Ca, Cl and Br in leaf were kept constant in spite of twice or three times higher concentration of these elements in leaf petiole. After flowering, selective element accumulation was observed during seed development, where most of the elements were accumulated into seed wall, not in seed. Higher concentration of the elements in elder leaf, which falls into ground and will be reused as plant nutrient, might reflect the recycling system of the elements in plants.     

Trace elements in head hair of hemodialysis patients

Instrumental neutron activation analysis /INAA/ was applied to measure trace elements in head hair of 19 patients with impaired renal function /14 males and 5 females/ and of 40 normal individuals /20 males and 20 females/. It was the aim to use head hair as a possible indicator of total body trace elements status and to investigate whether significant changes occur as a result of chronic hemodialysis. The elemental concentrations of 20 elements /i.e. Na, Mg, Al, Cl, K, Ca, V, Mn, Fe, Co, Cu, Zn, As, Se, Br, Ag, Cd, Sb, I and Au/ are presented and compared with published data. The present study revealed that the hair of the dialysis patients contained about ten times more iodine than that of the control group. No significant differences were observed for the other elements measured, except for sodium and antimony.     

HCHO+X(X=F、Cl、Br)的反应机理

采用CCSD/6-311++G(d,p)//B3LYP/6-311++G(d,p)方法研究了HCHO与卤素原子X(X=F、Cl、Br)的反应机理. 计算结果表明, 卤素原子X(X=F、Cl、Br)主要通过直接提取HCHO中的H原子生成HCO+HX(X=F、Cl、Br). 另外还可以生成稳定的中间体, 中间体再通过卤原子夺氢和氢原子直接解离两个反应通道分别生成HCO+HX(X=F、Cl、Br)和H+XCHO(X=F、Cl、Br). 其中卤原子夺氢通道为主反应通道, HCO和HX(X=F、Cl、Br)为主要的反应产物; 且三个反应的活化能均较低, 说明此类反应很容易进行, 计算结果与实验结果符合很好. 电子密度拓扑分析显示, 在HCHO+X反应通道(b)中出现了T型结构过渡态, 结构过渡态(STS)位于能量过渡态(ETS)之后. 并且按F、Cl、Br的顺序, 结构过渡态出现得越来越晚.     

溴与其他卤族元素及卤水溴、氯含量与矿化度的相关关系

研究了地下卤水、土壤、食品和人体组织中Br与其他卤族元素,以及卤水Br、Cl含量与矿化度的相关关系.结果表明,Br与Cl及Br与Ⅰ呈显著正相关关系,其他卤族元素间无显著相关性;Br与矿化度及Cl与矿化度高度相关.利用建立的各类卤水的回归模型,评估了“浓缩均衡矿物滴”(CMD)的盐卤属性.     

Determination of trace elements in human brain tissues using neutron activation analysis

Neutron activation analysis was applied to assess trace element concentrations in brain tissues from normal (n = 21) and demented individuals (n = 21) of both genders aged more than 50 years. Concentrations of the elements Br, Fe, K, Na, Rb, Se and Zn were determined. Comparisons were made between the results obtained for the hippocampus and frontal cortex tissues, as well as, those obtained in brains of normal and demented individuals. Certified reference materials, NIST 1566b Oyster Tissue and NIST 1577b Bovine Liver were analyzed for quality of the analytical results.     

Picosecond pulse radiolysis of direct and indirect radiolytic effects in highly concentrated halide aqueous solutions

Recently we measured the amount of the single product, Br(3)(-), of steady-state radiolysis of highly concentrated Br(-) aqueous solutions, and we showed the effect of the direct ionization of Br(-) on the yield of Br(3)(-). Here, we report the first picosecond pulse-probe radiolysis measurements of ionization of highly concentrated Br(-) and Cl(-) aqueous solutions to describe the oxidation mechanism of the halide anions. The transient absorption spectra are reported from 350 to 750 nm on the picosecond range for halide solutions at different concentrations. In the highly concentrated halide solutions, we observed that, due to the presence of Na(+), the absorption band of the solvated electron is shifted to shorter wavelengths, but its decay, taking place during the spur reactions, is not affected within the first 4 ns. The kinetic measurements in the UV reveal the direct ionization of halide ions. The analysis of pulse-probe measurements show that after the electron pulse, the main reactions in solutions containing 1 M of Cl(-) and 2 M of Br(-) are the formation of ClOH(-?) and BrOH(-?), respectively. In contrast, in highly concentrated halide solutions, containing 5 M of Cl(-) and 6 M of Br(-), mainly Cl(2)(-?) and Br(2)(-?) are formed within the electron pulse without formation of ClOH(-?) and BrOH(-?). The results suggest that, not only Br(-) and Cl(-) are directly ionized into Br(?) and Cl(?) by the electron pulse, the halide atoms can also be rapidly generated through the reactions initiated by excitation and ionization of water, such as the prompt oxidation by the hole, H(2)O(+?), generated in the coordination sphere of the anion.     

Some measures for making halogen bonds stronger than hydrogen bonds in H2CS-HOX (X = F, Cl, and Br) complexes

The properties and applications of halogen bonds are dependent greatly on their strength. In this paper, we suggested some measures for enhancing the strength of the halogen bond relative to the hydrogen bond in the H(2)CS-HOX (X = F, Cl, and Br) system by means of quantum chemical calculations. It has been shown that with comparison to H(2)CO, the S electron donor in H(2)CS results in a smaller difference in strength for the Cl halogen bond and the corresponding hydrogen bond, and the Br halogen bond is even stronger than the hydrogen bond. The Li atom in LiHCS and methyl group in MeHCS cause an increase in the strength of halogen bonding and hydrogen bonding, but the former makes the halogen bond stronger and the latter makes the hydrogen bond stronger. In solvents, the halogen bond in the Br system is strong enough to compete with the hydrogen bond. The interaction nature and properties in these complexes have been analyzed with the natural bond orbital theory.     

C12-3-C12·2Br及C12-3（OH）-C12·2Br水溶液的胶团聚集数及流变特征

采用荧光探针法测定了C12-3-C12·2Br及C12-3(OH)-C12·2Br Gemini表面活性剂胶团聚集数,结果表明,浓度极大影响其胶团聚集数,当浓度为各自临界胶团浓度的5.5倍时,由于联结链中羟基的作用,C12-3(OH)-C12·2Br的胶团聚集数为44.7,远大于C12-3-C12·2Br的33.2;C12-3-C12 ·2Br浓度直至64 mmol/L,C12-3(OH)-C12·2Br浓度直至54 mmol/L,剪切速度γ在0～1 875 s-1范围内,流变行为表现出牛顿体特征;在其后浓度的范围,临界剪切速度γ*以上时,为非牛顿体特征.黏度随浓度增大而增大并有—上升拐点;在联结链上引入羟基,对流变行为影响不大,但在相同条件下,黏度略微增大.     

A comparative study of IC,ICP-AES,and NAA measurements on chlorine,bromine, and sodium in natural waters

A suite of shallow and deep subsurface waters from southwestern Illinois has been analyzed for chlorine (CT), bromine (Br^?), and sodium (Na⁺) using three different methods. Cl and Br were analyzed by ion chromatography (IC) and neutron activation analysis (NAA). Na was analyzed using inductively coupled plasma-atomic emission spectrometry (ICP-AESS) and NAA. In addition, five water standards were prepared with compositions over the range of Cl, Br, and Na concentrations in the natural waters were analyzed using the same methods. Analytical results for the prepared standards by the different methods were in good agreement. However, analytical results on natural waters yielded generally poor agreement between the methods. Our results suggest that solute concentrations and ratios between major solutes in subsurface waters determined by IC and ICP-AES may involve substantial laboratory error.