Whole body metabolic responses to brain trauma in the rat

Hotien prefecture, Xinjiang Province, China, in the Taklamakan Desert, is an area of severe iodine deficiency. Because usual methods of iodine supplementation failed here, we began supplementation in 1992 with potassium iodate, which was added to irrigation water (Lancet 1994; 334:107-110). We report 4 y experience with this method in 3 townships that contained a total treated population of 37,000. Potassium iodate was dripped into irrigation water (to a concentration 10-80 microg/l) during a 2- to 4-wk period. During the 3 y that followed, no further supplementation was made, and iodine concentrations increased several fold in crops and plants, sheep and chicken thyroid glands, and meat and in urine of children 2-6 y of age and of women who were of childbearing age. Infant mortality decreased 50%, and sheep production increased 43%. Iodine repletion of soil through irrigation water is an effective and cost-efficient way of providing iodine in appropriate situations.     

A fundamental rotating disk study of gold dissolution in iodine-iodide solutions

The dissolution of gold in iodine-iodide solutions was studied using the rotating disc technique. The effect of changes on disc rotational speed, temperature, iodine and iodide concentrations, solution pH and various additives were investigated. Kinetic data and thermodynamic considerations were used to explain the fundamental aspects of the process. Gold can be leached at a greater rate by iodine-iodide solution than is possible by thiourea and by the conventional cyanidation techniques.     

Serial renal transplant surgery: technical reflections concerning third transplants

Iodine distribution was studied in isolated porcine eyes after iontophoresis using 131I-labelled solutions and chemical methods. After a 15-min treatment with a therapeutically used iodine brine, the iodine content in the ocular tissues showed the following rank order: cornea > retina > vitreous body > anterior chamber fluid > lens. Replacement of the brine by 0.15 M NaI increased the uptake values in a different way, but the same rank order was maintained. The increase was highest in the cornea (5.6-fold) and only about 2-fold in the lens, nevertheless approaching now the level of 10(-4) M, a concentration which was regarded as being optimal for the antioxidant effect of I-. Among the other eye components, the relatively high iodine enrichment of the retina was remarkable. The data are discussed with respect to a possible protective, antioxidative and OH-scavenging efficacy of I- and to previous results in the literature concerning iodine uptake in ocular tissues.     

Determination of iodine in milk and oyster tissue samples using combustion and peroxydisulfate oxidation

Two methods are described for the preparation of samples for total iodine measurement in biological matrices. In the first method, the samples were combusted in a stream of oxygen to release iodine that, subsequently, was trapped in a solution as iodide. The second method is a new approach in which the samples were oxidized in a basic solution of peroxydisulfate. In this case, the iodine was retained in solution as iodate. Total iodine was measured by gas chromatographic analysis of the 2-iodopentan-3-one derivative. The methods were tested using Standard Reference Materials (SRMs) 1549 Non-Fat Milk Powder, and 1566a and 1566 Oyster Tissue. Also, KI and KIO3 were used for testing the procedures. The results obtained for the SRMs, given as average +/- standard deviation in micrograms g-1, were: 3.39 +/- 0.14 and 3.40 +/- 0.23 for SRM 1549; 4.60 +/- 0.42 and 4.51 +/- 0.45 for SRM 1566a; and 2.84 +/- 0.16 and 2.76 +/- 0.06 for SRM 1566; values corresponding to combustion and wet oxidation, respectively. Overall, the absolute recoveries varied between 91 and 103%. These methods can also be used in the preparation of targets for the measurement of 129I using accelerator mass spectrometry.     

碘量法测定铜在铜镍合金中的应用及理论探讨

本方法基玗pH值～4的微酸性溶液中,用氟化氢铵掩蔽Fe＾3＋,二价铜与碘化钾反应生成碘化亚铜沉淀并析出碘,以淀粉为指示剂,用硫代硫酸钠标准溶液滴定所析出的碘,既可测定出铜的含量,并对分析方法的理论进行了探讨     

Selective separation of nickel from cobalt in ammoniacal solutions by emulsion type liquid membranes using 8-hydroxyquinoline (8-HQ) as mobile carrier

The selective separation and concentration of nickel from ammoniacal solutions containing nickel and cobalt by an emulsion liquid membrane (ELM) technique using 8-hydroxyquinoline (8-HQ) as carrier has been examined. The emulsion liquid membrane consists of a diluent (kerosene), a surfactant (ECA 4360J), a carrier (8-HQ), and a stripping solution (0.025 M EDTA solution, buffered at pH 4.0). Cobalt (II) in the 6 M ammonia feed solution was oxidised to cobalt (III) by adding H₂O₂ and the pH adjusted to 10 with hydrochloric acid (HCl). The important variables were found to be membrane composition, ammonia concentration, diluent type, surfactant concentration, extractant concentration, EDTA concentration in the stripping solution, pH of the feed and the stripping solutions, phase ratio, and treatment ratio. It was possible to selectively extract 96.5 to 99.0% of nickel from a mixture of nickel and cobalt.     

Hydraulic Conductivity and Swelling of Nonprehydrated GCLs Permeated with Single-Species Salt Solutions

The influence of single-species salt solutions of various concentration, cation valence, and pH on swelling and hydraulic conductivity of nonprehydrated GCLs was examined. At similar concentration, swell was largest with NaCl, KCl, and LiCl solutions (monovalent cations Na+, K+, and Li+) and smallest with LaCl3 solutions (trivalent cation La3+). Intermediate swell volumes were obtained with divalent solutions (CaCl2, MgCl2, ZnCl2, and CuCl2). Analogous results were obtained from hydraulic conductivity tests. GCL specimens permeated with solutions containing divalent or trivalent cations had higher hydraulic conductivity than GCLs permeated with monovalent solutions or deionized water, unless the divalent or trivalent solutions were very dilute (≤0.01 M). Hydraulic conductivity increased as the concentration increased, and at high concentration (1 M) only small differences existed between hydraulic conductivities measured with all solutions. Swelling and hydraulic conductivity were related to size of the hydrated cation for monovalent cations, but no relationship was observed for different species of divalent and trivalent cations provided that the valence was the same. However, pH only influenced swelling and hydraulic conductivity when the pH was very low (<3) or very high (>12).     

Technology of Chloride-Ion Utilization from Filtrates of Carbonate Circuit of Nickel Production

The problem of sulphate solution purification, in particular solutions of carbonate branch after nickel precipitation, from chloride ion can be solved effectively by extraction process. Trialkylamine available commercially (TAA) (alkyl—C₈-C₁₀ and C₇-C₉) has been used in this study. The dependences of chloride ion extraction on temperature, pH and composition of aqueous phase, and composition of organic phase have been investigated. Triethylbenzene, kerosene, diesel oil, syntin with different additions (2-ethylhexanol, hexanol, tributylphosphate) were used as the solvents. The optimum composition of organic phase (0.5-0.6 M TAA in kerosene with addition of 2-ethylhexanol) and the conditions of chloride ion extraction from sulphate solutions have been determined. Chloride ion stripping from organic phase was conducted by alkali solutions to obtain a concentrated solution of sodium chloride.

The technology of chloride ion recovery from filtrates of carbonate branch of nickel plant (Norilsk Mining and Metallurgical plant) has been developed and tested on an industrial scale. The initial filtrate contained in g/l: chloride ion I6-I8, sulphate ion 60-65, impurities of metals. After purification, the chloride ion concentration in solution was less than 0.3 g/l (chloride ion recovery was more than 95%). After stripping of chloride ion with alkali solution, the stripping solutions containing 200-220 g/l NaCl and < 2 g/l sulphate ion. The stripping solutions underwent an electrolysis to obtain chlorine and sodium hydroxide solutions.

The developed technology allows recovery of chloride ion from sulphate solution.     

Gallium extraction from synthetic Bayer liquors using Kelex 100-kerosene,the effect of loading and stripping conditions on selectivity

Solvent extraction with Kelex 100 has been recognised as a possible method for recovering gallium from Bayer liquors, but the practical process has not been so attractive as to cause a general technological break-through. The purpose of this research was to enhance the Ga/Al selectivity and efficiency of the extraction and re-extraction processes, while making the method as simple as possible. Instead of applying various additives and modifiers, the approach was based on the fundamental extraction kinetics with the pure kerosene/Kelex 100 system and a method of selective re-extraction boosted by possible chloro-complex formation in HCl media. The main factors examined during the extraction tests were solution pH, concentration of Al, amount of the reagent and the intensity of agitation, whereas HCl concentration was varied to improve the performance of the re-extraction step. The extraction results were interpreted in terms of the heterogeneous transfer mechanism. A Ga/Al selectivity index of almost 100 could be achieved at a Ga yield of ∼ 70% with 10–20% Kelex 100 in kerosene and the pH set to ∼ 14.3 from a NaOH solution containing 100 ppm Ga and 1100 ppm Al. As a practical source, the zeolite mother liquor has also proved suitable for the procedure. Aluminium carried over to the extractant can be separated from gallium during the combined re-extraction procedure, removing aluminium with 5–6 M HCl from the organic phase, then eluting gallium with ∼ 2 M hydrochloric acid solution.     

The direct electrowinning of gold from dilute cyanide leach liquors

A cylindrical electrowinning cell employing a three-dimensional steel wool cathode has been used to investigate the effect of free cyanide concentration, pH, solution conductivity and base metal impurities on the electrowinning of gold from alkaline cyanide leach liquors containing up to 5 mg/l gold. The recovery of gold in a given time decreased: (a) as the pH decreased below 13, (b) if more than 10 mg/l of Fe, Cu, Zn or Hg were present in solution, (c) as the free NaCN concentration was increased, (d) with decreasing conductivity of the solution. High gold recoveries can be obtained with relatively low electrical energy consumption; greater than 96% recovery in one hour from 5 mg/l gold solutions with an electrical energy consumption of 112 kWh/kg at a current efficiency of 0.33% is possible.Experimentally derived graphs of solution concentration versus time of electrolysis were analysed by means of a simple reactor model and approximate mass transfer coefficients were calculated. These were compared with coefficients calculated from data on the performance of Mintek cells in South African gold recovery operations. The application of these data to the prediction of required electrode area and hence cost for a commercial dilute electrowinning installation is discussed.     

Iodine deficiency in cardiovascular diseases

The thyroid hormone deficiency on cardiovascular function can be characterized with decreased myocardial contractility and increased peripheral vascular resistance as well as with the changes in lipid metabolism. 42 patients with cardiovascular disease (mean age 65 +/- 13 yr, 16 males) were investigated if iodine insufficiency can play a role as a risk factor for the cardiovascular diseases. The patients were divided in 5 subgroups on the ground of the presence of hypertension, congestive heart failure, cardiomyopathy, coronary disfunction and arrhythmia. Urine iodine concentration (5.29 +/- 4.52 micrograms/dl) was detected with Sandell-Kolthoff colorimetric reaction. The most decreased urine iodine concentration was detected in the subgroups with arrhythmia and congestive heart failure (4.7 +/- 4.94 micrograms/dl and 4.9 +/- 4.81 micrograms/dl, respectively). An elevated TSH level was found by 3 patients (5.3 +/- 1.4 mlU/l). An elevation in lipid metabolism (cholesterol, triglyceride) associated with all subgroups without arrhythmia. In conclusion, the occurrence of iodine deficiency in cardiovascular disease is frequent. Iodine supplementation might prevent the worsing effect of iodine deficiency on cardiovascular disease.     

Production of a mixture of antimicrobial organic acids from lactose by co-culture of Bifidobacterium longum and Propionibacterium freudenreichii

The antimicrobial activities of standard solutions of three organic acids (lactic, acetic, and propionic acids) were compared using Micrococcus luteus, Pseudomonas sp. and Staphylococcus aureus as test microorganisms. At the same concentrations of the undissociated form, the antimicrobial activities of acetic and propionic acids were higher than that of lactic acid, irrespective of test microorganisms. In a single cultivation of Bifidobacterium longum, a mixture of lactic (17 g/l) and acetic (20 g/l) acids was produced from 50 g/l lactose and its antimicrobial activities against M. luteus, Pseudomonas sp., and S. aureus correspond to that of 32, 19, and 25 g/l of acetic acid, respectively. To increase the total antimicrobial activity, a co-culture of B. longum and Propionibacterium freudenreichii, in which lactic acid produced once from lactose by B. longum was converted to acetic and propionic acids by P. freudenreichii, was done using TPY medium containing commercially available peptones as a nitrogen source. By the sequential conversion of lactose using the two microorganisms, the culture supernatant containing a mixture of acetic (27 g/l) and propionic (13 g/l) acids without lactic acid was produced. The antimicrobial activities of the mixture against M. luteus, Pseudomonas sp., and S. aureus were 35, 30, and 26 g/l as a concentration of acetic acid, respectively, higher than that obtained in the cultivation of B. longum alone. When the medium containing an enzymatic hydrolyzate of whey proteins with a protease was used in the co-culture of B. longum and P. freudenreichii, the culture supernatant containing the mixture of organic acids was also obtained in the same manner as the co-culture using TPY medium and the activities were 43, 29, and 29 g/l as a concentration of acetic acid for M. luteus, Pseudomonas sp. and S. aureus, respectively.     

Thyroid peroxidase: kinetics, pH optima and substrate dependency

The oxidation of iodide, guaiacol and 2,2'-azino-di[3-ethyl-benzthiazoline-(6)-sulphonic acid] and the iodination of tyrosyl residues in bovine serum albumin, catalysed by partly purified thyroid peroxidase, were studied. The enzyme showed pH optima with all electron donors. With the exception of guaiacol, the position of the pH optima depended upon both the electron donor and hydrogen peroxide concentrations. With increased hydrogen peroxide concentrations the optima shifted to lower pH, and with increased iodide concentration to higher pH. For monoiodotyrosine (MIT) formation in bovine serum albumin the position of the pH optimum was also dependent on the hydrogen peroxide concentrations. The position of the pH optimum of the oxidation of guaiacol was pH 9 and independent of substrate and hydrogen peroxide concentrations. It is obvious from these findings that iodination reactions must be studied under well-defined conditions.     

The coprecipitation behavior of Co(II) and Ni(II) with Fe(III), Cr(III) and Al(III) from aqueous ammoniacal solutions

The coprecipitation of cobalt(II) and nickel(II) with iron(III), chromium(III) and aluminum(III) from ammoniacal solutions has been investigated. The coprecipitation behavior was found to be very sensitive to the solution pH and total ammonia concentration. Co(II) and Ni(II) can be precipitated from low ammonia concentration solutions but are readily redissolved at higher ammonia concentrations. The coprecipitate of divalent and trivalent species was found to contain very large amounts of the divalent metals (up to a mole ratio M M(II)/M(III) of 2.5) when aluminum was the trivalent species, whereas with iron(III) or chromium(III), the ratio was only 0.5.     

Localised corrosion behaviour of high and low nitrogen Cr-Mn steels

It is well established that addition of nitrogen to steels improves the pitting corrosion resistance of steels. To elucidate the role of nitrogen, electrochemical and surface analytical studies were carried out on Cr-Mn steels with low (0.0075 %) and high (0.9 %) nitrogen contents. The incubation time for pitting, measured in sodium sulphate solutions containing different concentrations of chloride was higher for the high nitrogen steel. The pit initiation process was found to be first order with respect to chloride concentration. The passive current density was one order lower than that of nitrogen free steel. The grain broundary attack observed in low nitrogen steel was not present in high nitrogen steel. XPS analysis indicated nitrogen enrichment at the surface in the passive layer. This may be one reason for the higher pitting resistance of nitrogen containing steel besides formation of ammonium ions and rising pH.     

Gas-liquid chromatographic determination of total inorganic iodine in milk

Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 microgram/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.     

Iodine effects in body tissues - a survey and biophysical approach to interpretation (author's transl)

An attempt was made to interpret the therapeutic and biological effects of iodine on the basis of currently available biophysical information. The easily facilitated electron transfer from and to the external shell of the iodine atom is considered to account, first of all, for good tissue compatibility of molecular iodine as an oxidizing antiseptic, secondly, for the role of iodine as a biocatalyzer of oxidation and reduction processes, thirdly, for the role of iodine as an agent lowering the electric resistance of membranes and, finally, for a possible intracellular release of iodine from iodine-containing hormones and amino acids, thereby affecting enzyme activities. A low electrostatic charge density of iodide and, hence, a small ionic hydration shell imply two biologically significant facts: an intensified ionic mobility and a breaking of the immediate water structure (chaotropy). These physical phenomena are thought to be well suited to explain the strong binding capacity of iodide to proteins, the loosening of electrostatic and hydrophobic bonds within the tissues and an overall increase in protein solubility.     

Polychromatic UV Fluence Measurement Using Chemical Actinometry, Biodosimetry, and Mathematical Techniques

With the growing acceptance of ultraviolet (UV) irradiation for disinfection of water and wastewater, the use of medium pressure Hg-based UV lamps and nonmercury, pulsed UV lamps emitting polychromatic light, are being considered in place of low-pressure, monochromatic UV lamps. However, traditional methods of fluence measurement developed for monochromatic light sources are not appropriate for polychromatic light sources. New approaches for estimation of effective germicidal fluence for polychromatic UV sources were investigated integrating chemical actinometry (uridine and iodide/iodate) with mathematical modeling. Actinometric fluence measurements as well as radiometry were referenced against microbial biodosimetry. Combining traditional chemical actinometry with mathematical analysis improved the accuracy of incident and germicidal polychromatic UV fluence measurement. Uridine actinometer germicidal fluence measurement, with or without mathematical correction, was just outside of the 95% confidence interval of that measured by biodosimetry. Similarly, an iodide/iodate actinometer was observed to accurately measure incident fluence, and coupled with mathematical corrections, it measured germicidal fluence within the 95% confidence interval of that measured by biodosimetry. These methods have potential to develop into flexible, convenient ways to measure germicidally effective UV fluence from any type of UV lamp.     

Hypothyroid patients showing shortened responsiveness to oral iodized oil have paradoxically low serum thyroglobulin and low thyroid reserve. Thyroglobulin/thyrotropin ratio as a measure of thyroid damage

In Central Africa, all of northern Zaire is very severely deficient in iodine. A peculiar feature of this endemia is that iodine deficiency and the ensuing thyroid gland stimulation not only leads to goitre formation but also to progressive thyroid involution and to myxoedematous cretinism. An iodine supplementation trial based on oral administration of small doses of iodine was made in 81 schoolchildren. All of them received a small dose of iodine (0.1 ml containing 48 mg) per os and the thyroid status was followed during 4 months. Blood and urine samples were collected at the start of the study, then 2 weeks, 2 months and 4 months after iodine administration. Before iodine supplementation the mean urinary iodine level was 0.18 +/- 0.02 micromol/l, and 10% of the subjects had a urinary iodine level below 0.08 micromol/l. Fifty-two percent of the subjects had a serum thyrotropin (TSH) level above 10 mU/l. All the subjects responded to the administration of iodine. and all of them recovered a euthyroid status. Most of them were still euthyroid at the end of the study. However. within 4 or even 2 months, some subjects (15 % of the total) reverted to hypothyroidism. At the entry of the study these subjects were all hypothyroid and had elevated TSH and paradoxically low serum thyroglobulin (TG) values. In myxoedematous cretins living in the same area, even lower serum TG levels were found. Together with the absence of goitre, a paradoxically low serum TG Suggests a low thyroid reserve, and in the present case a reduced amount of functional thyroid tissue. We show that the serum TG/TSH ratio may be used as a predictive index of thyroid reserve and of positive response to iodine administration. These data further suggest that thyroid damage is not confined to myxoedematous cretins. but is widely distributed in the phenotypically normal population. Widely distributed thyroid damage may render iodine prophylaxis based on oral administration unpredictable.     

用4种溶液对金、银和铂进行溶解的研究

在25℃下，用4种溶液对金，银和铂进行溶解，在金的溶解中，用王水和碘／碘化钠（I^-3/I^-）溶液对金有较快的溶解速度，漂白粉－HCl-NaCl溶液和Fe2(SO4)3-H2SO4/硫脲溶液对金的溶解速度较慢，在银的溶解中，只有Fe2(SO4)3-H2SO4／硫脲溶液对银有明显的溶解作用，其余3种溶液只能缓慢溶解极少量银，4种溶液对铂均无明显的溶解作用。