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Showing papers on "Iodine published in 2008"


Journal ArticleDOI
TL;DR: Using x-ray absorption spectroscopy, it is shown that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS) and is the first to be described in a living system.
Abstract: Brown algae of the Laminariales (kelps) are the strongest accumulators of iodine among living organisms. They represent a major pump in the global biogeochemical cycle of iodine and, in particular, the major source of iodocarbons in the coastal atmosphere. Nevertheless, the chemical state and biological significance of accumulated iodine have remained unknown to this date. Using x-ray absorption spectroscopy, we show that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS). We propose here that its biological role is that of an inorganic antioxidant, the first to be described in a living system. Upon oxidative stress, iodide is effluxed. On the thallus surface and in the apoplast, iodide detoxifies both aqueous oxidants and ozone, the latter resulting in the release of high levels of molecular iodine and the consequent formation of hygroscopic iodine oxides leading to particles, which are precursors to cloud condensation nuclei. In a complementary set of experiments using a heterologous system, iodide was found to effectively scavenge ROS in human blood cells.

323 citations


Journal ArticleDOI
TL;DR: Four methods are recommended for assessment of iodine nutrition: urinary iodine concentration, the goitre rate, and blood concentrations of thyroid stimulating hormone and thyroglobulin, and serum ferritin remains the best indicator of iron stores in the absence of inflammation.
Abstract: Four methods are recommended for assessment of iodine nutrition: urinary iodine concentration, the goitre rate, and blood concentrations of thyroid stimulating hormone and thyroglobulin. These indicators are complementary, in that urinary iodine is a sensitive indicator of recent iodine intake (days) and thyroglobulin shows an intermediate response (weeks to months), whereas changes in the goitre rate reflect long-term iodine nutrition (months to years). Spot urinary iodine concentrations are highly variable from day-to-day and should not be used to classify iodine status of individuals. International reference criteria for thyroid volume in children have recently been published and can be used for identifying even small goitres using thyroid ultrasound. Recent development of a dried blood spot thyroglobulin assay makes sample collection practical even in remote areas. Thyroid stimulating hormone is a useful indicator of iodine nutrition in the newborn, but not in other age groups. For assessing iron status, haemoglobin measurement alone has low specificity and sensitivity. Serum ferritin remains the best indicator of iron stores in the absence of inflammation. Measures of iron-deficient erythropoiesis include transferrin iron saturation and erythrocyte zinc protoporphyrin, but these often do not distinguish anaemia due to iron deficiency from the anaemia of chronic disease. The serum transferrin receptor is useful in this setting, but the assay requires standardization. In the absence of inflammation, a sensitive method to assess iron status is to combine the use of serum ferritin as a measure of iron stores and the serum transferrin receptor as a measure of tissue iron deficiency.

252 citations


Journal ArticleDOI
TL;DR: An all-solid-state dye-sensitized solar cell with total photoelectric conversion efficiency of 5.64% under AM 1.5 simulated solar light (100 mW/cm2) illumination is achieved.
Abstract: Using poly(N-methyl-4-vinyl-pyridine iodide), N-methyl-pyridine iodide and iodine, a solid polymer electrolyte with conductivity of 6.41 mS/cm is prepared. On the basis of a solid polymer electrolyte, a conducting graphite layer, a KI block layer, and a vacuum assembling technique, we achieve an all-solid-state dye-sensitized solar cell with total photoelectric conversion efficiency of 5.64% under AM 1.5 simulated solar light (100 mW/cm2) illumination.

249 citations


Journal ArticleDOI
TL;DR: A longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency was performed in this paper. And the number of urine samples needed to determine the iodine excretion level for crude urinary iodine and for 24-hour iodine consumption from age and gender-specific creatinine excretions was calculated.
Abstract: The iodine intake level in a population is determined in cross-sectional studies. Urinary iodine varies considerably and the reliability of studies of iodine nutrition and the number of samples needed is unsettled. We performed a longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency. Iodine and creatinine concentrations were measured in spot urine samples collected monthly for 13 months. From these data we calculated the number of urine samples needed to determine the iodine excretion level for crude urinary iodine and for 24 h iodine excretion estimated from age- and gender-specific creatinine excretions. We found that mean urinary iodine excretion varied from 30 to 87 microg/l (31 to 91 microg/24 h). Sample iodine varied from 10 to 260 microg/l (20 to 161 microg/24 h). Crude urinary iodine varied more than estimated 24 h iodine excretion (population standard deviation 32 v. 26; individual standard deviation 29 v. 21; Bartlett's test, P < 0.01 for both). The number of spot urine samples needed to estimate the iodine level in a population with 95 % confidence within a precision range of +/- 10 % was about 125 (100 when using estimated 24 h iodine excretions), and within a precision range of +/- 5 % was about 500 (400). A precision range of +/- 20 % in an individual required twelve urine samples or more (seven when using estimated 24 h iodine excretions). In conclusion, estimating population iodine excretion requires 100-500 spot urine samples for each group or subgroup. Less than ten urine samples in an individual may be misleading.

235 citations


Journal ArticleDOI
Seigo Amachi1
TL;DR: This review summarizes current knowledge on interactions between microorganisms and iodine, with special emphasis on newly isolated bacteria possibly contributing to the cycling of iodine on a global scale.
Abstract: Iodine is an essential trace element for humans and animals because of its important role as a constituent of thyroid hormones. If the anthropogenic iodine-129 (129I, half-life: 1.6×107 years), which is released from nuclear facilities into the environment and has a long half-life, participates in the biogeochemical cycling of iodine, it potentially accumulates in the human thyroid gland and might cause thyroid cancer. Therefore, it is necessary to obtain better information on the behavior of iodine in the environment for accurate safety assessments of 129I. Major pathways of iodine cycling are the volatilization of organic iodine compounds into the atmosphere, accumulation of iodine in living organisms, oxidation and reduction of inorganic iodine species, and sorption of iodine by soils and sediments. Considerable geochemical evidence has indicated that these processes are influenced or controlled by microbial activities, although the precise mechanisms involved are still unclear. This review summarizes current knowledge on interactions between microorganisms and iodine, with special emphasis on newly isolated bacteria possibly contributing to the cycling of iodine on a global scale.

136 citations


Journal ArticleDOI
TL;DR: Prolonged iodized salt significantly improves maternal thyroid economy and reduces the risk of maternal thyroid insufficiency during gestation, probably because of a nearly restoring intrathyroidal iodine stores.
Abstract: Context: Mild to moderate iodine deficiency during pregnancy can cause transient maternal hypothyroidism and impaired mental development of the progeny. These unfavorable effects are preventable by iodine supplementation. In Europe, however, less than 50% pregnant women receive iodine-containing supplements, thus representing dietary iodized salt the only carrier of iodine for most women in this life stage. Objective/Design: This longitudinal study is aimed to investigate the effects of long-term iodized salt consumption on maternal thyroid function during gestation. Participants/Outcome Measures: We prospectively evaluated thyroid function in 100 consecutive thyroperoxidase antibody-negative pregnant women from a mildly iodine-deficient area. Sixty-two women who had regularly used iodized salt for at least 2 yr prior to becoming pregnant and 38 who commenced iodized salt consumption upon becoming pregnant were classified as long-term (LT) and short-term (ST) iodine supplemented, respectively. Results: Lo...

117 citations


Journal ArticleDOI
TL;DR: Iodine is significantly lost upon high humidity storage but light or dry heat has little effect%; there is much recent literature on iodine sufficiency and uptake inhibitors; there is also much misinformation and disinformation.
Abstract: Adequacy of iodine nutrition in the United States has lately been of concern. A major source of dietary iodine for the U.S. population is iodized salt. The U.S. Food and Drug Administration (USFDA) recommends 60–100 mg KI/kg salt, equivalent to 46–76 mg I/kg salt. All U.S. iodized salt contains 45 mg I/kg according to labels. We collected samples of table salt from freshly opened containers from U.S. volunteers. A sample was sent to us when the can was first purchased. Subsets of volunteers sent further samples when the salt container became half-empty through normal use and a further final sample when the container was nearly finished. We also looked at iodine distribution homogeneity within individual containers, loss of iodine from salt upon exposure to humidity and sunlight, and upon short-term heating (dry and in solution) as may be encountered in cooking. Measurements were made in 0.01% w/v salt solutions by induction coupled plasma−mass spectrometry with 72Ge as an internal standard. The median and...

110 citations


Journal Article
TL;DR: The safety of therapeutic doses of iodine above the established safe upper limit of 1 mg is evident in the lack of toxicity in the Japanese population that consumes 25 times the median intake of iodine consumption in the United States.
Abstract: Iodine deficiency is generally recognized as the most commonly preventable cause of mental retardation and the most common cause of endocrinopathy (goiter and primary hypothyroidism). Iodine deficiency becomes particularly critical in pregnancy due to the consequences for neurological damage during fetal development as well as during lactation. The safety of therapeutic doses of iodine above the established safe upper limit of 1 mg is evident in the lack of toxicity in the Japanese population that consumes 25 times the median intake of iodine consumption in the United States. Japan’s population suffers no demonstrable increased incidence of autoimmune thyroiditis or hypothyroidism. Studies using 3.0- to 6.0-mg doses to effectively treat fibrocystic breast disease may reveal an important role for iodine in maintaining normal breast tissue architecture and function. Iodine may also have important antioxidant functions in breast tissue and other tissues that concentrate iodine via the sodium iodide symporter. (Altern Med Rev 2008;13(2):116-127)

101 citations


Journal ArticleDOI
TL;DR: Brown algal kelp species are the most efficient iodine accumulators among all living systems, with an average content of 1.0% of dry weight in Laminaria digitata, and iodine is mainly stored in the apoplasm and not in an intracellular compartment as previously proposed.
Abstract: Brown algal kelp species are the most efficient iodine accumulators among all living systems, with an average content of 1.0% of dry weight in Laminaria digitata. The iodine distributions in stipe and blade sections from L. digitata were investigated at tissue and subcellular levels. The quantitative tissue mapping of iodine and other trace elements (Cl, K, Ca, Fe, Zn, As and Br) was provided by the proton microprobe with spatial resolutions down to 2 mum. Chemical imaging at a subcellular resolution (below 100 nm) was performed using the secondary ion mass spectrometry microprobe. Sets of samples were prepared by both chemical fixation and cryofixation procedures. The latter prevented the diffusion and the leaching of labile inorganic iodine species, which were estimated at around 95% of the total content by neutron activation analysis. The distribution of iodine clearly shows a huge, decreasing gradient from the meristoderm to the medulla. The contents of iodine reach very high levels in the more external cell layers, up to 191 +/- 5 mg g(-1) of dry weight in stipe sections. The peripheral tissue is consequently the main storage compartment of iodine. At the subcellular level, iodine is mainly stored in the apoplasm and not in an intracellular compartment as previously proposed. This unexpected distribution may provide an abundant and accessible source of labile iodine species which can be easily remobilized for potential chemical defense and antioxidative activities. According to these imaging data, we proposed new hypotheses for the mechanism of iodine storage in L. digitata tissues.

101 citations


Journal ArticleDOI
TL;DR: Five years of excessive iodine intake by the Brazilian population may have increased the prevalence of CAT and hypothyroidism in subjects genetically predisposed to thyroid autoimmune diseases.
Abstract: Objective: To evaluate the prevalence of chronic autoimmune thyroiditis (CAT) and iodine-induced hypothyroidism, hyperthyroidism (overt and subclinical), and goiter in a population exposed to excessive iodine intake for 5 years (table salt iodine concentrations: 40-100 mg/kg salt). Design: This was a population-based, cross-sectional study with 1085 participants randomly selected from a metropolitan area in Sao Paulo, Brazil, and conducted during the first semester of 2004. Methods: Thyroid ultrasound examination was performed in all participants and samples of urine and blood were collected from each subject. Serum levels of thyroid-stimulating hormone, free thyroxine, and anti-thyroid peroxidase (TPO) antibodies, urinary iodine concentration, thyroid volume, and thyroid echogenicity were evaluated. We also analyzed table salt iodine concentrations. Results: At the time the study was conducted, table salt iodine concentrations were within the new official limits (20-60 mg/kg salt). Nevertheless, in 45.6% of the participants, urinary iodine excretion was excessive (above 300 mg/l) and, in 14.1%, it was higher than 400 mg/l. The prevalence of CAT (including atrophic thyroiditis) was 16.9% (183/1085), women were more affected than men (21.5 vs 9.1% respectively, PZ0.02). Hypothyroidism was detected in 8.0% (87/1085) of the population with CAT. Hyperthyroidism was diagnosed in 3.3% of the individuals (36/1085) and goiter was identified in 3.1% (34/1085). Conclusions: Five years of excessive iodine intake by the Brazilian population may have increased the prevalence of CAT and hypothyroidism in subjects genetically predisposed to thyroid autoimmune diseases. Appropriate screening for early detection of thyroid dysfunction may be considered during excessive nutritional iodine intake.

100 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the organic fraction of iodide in rain, snow, and aerosols in an attempt to further clarify aqueous phase iodine chemistry and found that iodide is the only thermodynamically stable sink species for iodine in the tro- posphere.
Abstract: Iodine oxides, such as iodate, should be the only thermodynamically stable sink species for iodine in the tro- posphere. However, field observations have increasingly found very little iodate and significant amounts of iodide and soluble organically bound iodine (SOI) in precipitation and aerosols. The aim of this study was to investigate io- dine speciation, including the organic fraction, in rain, snow, and aerosols in an attempt to further clarify aqueous phase iodine chemistry. Diurnal aerosol samples were taken with a 5 stage cascade impactor and a virtual impactor (PM2.5) from the Mace Head research station, Ireland, during sum- mer 2006. Rain was collected from Australia, New Zealand, Patagonia, Germany, Ireland, and Switzerland and snow was obtained from Greenland, Germany, Switzerland, and New Zealand. Aerosols were extracted from the filters with water and all samples were analysed for total soluble iodine (TSI) by inductively coupled plasma mass spectrometry (ICP-MS) and iodine speciation was determined by coupling an ion chromatography unit to the ICP-MS. The median concentra- tion of TSI in aerosols from Mace Head was 222 pmol m 3 (summed over all impactor stages) of which the majority was associated with the SOI fraction (median day: 90±4%, night: 94±2% of total iodine). Iodide exhibited higher concen- trations than iodate (median 6% vs. 1.2% of total iodine), and displayed significant enrichment during the day com- pared to the night. Interestingly, up to 5 additional, presum- ably anionic iodo-organic peaks were observed in all IC-ICP- MS chromatograms, composing up to 15% of the TSI. Sol- uble organically bound iodine was also the dominant frac- tion in all rain and snow samples, with lesser amounts of iodide and iodate (iodate was particularly low in snow). Two of the same unidentified peaks found in aerosols were also observed in precipitation from both Southern and Northern Hemispheres. This suggests that these species are transferred from the aerosols into precipitation and that they have ei- ther a relatively long lifetime or are rapidly recycled. It is thought that SOI is formed by reactions between HOI or I2 and organic matter derived from the ocean surface layer. SOI may then photolytically decompose to yield iodide and the unidentified species. The data in this study show that io- dine oxides are the least abundant species in rain, snow, and aerosols and therefore considerably more effort is required on aqueous phase iodine chemistry for a holistic understand- ing of the iodine cycle.

Journal ArticleDOI
TL;DR: In this article, perchlorate, thiocyanate, and iodine excretion in urine and milk of 13 breastfeeding women was investigated and the results were interpreted by a model of parallel/competitive transport of these species by the sodium iodide symporter.
Abstract: Perchlorate, thiocyanate, and iodine excretion in urine and milk of 13 breastfeeding women was investigated and the results were interpreted by a model of parallel/competitive transport of these species by the sodium iodide symporter. For each species i, we assumed physiological homeostasis, where iT,in equals the corresponding total excretion in urine and milk (ie,u + ie,m). The fraction of the total excretion that appeared in milk fi,m was measured and ranged from 0.394−0.781, 0.018−0.144, and 0.086−0.464 for perchlorate, thiocyanate, and iodine, respectively. The corresponding median values were 0.541, 0.053, and 0.177, respectively. The selectivity factors of perchlorate over iodide transport, and thiocyanate over iodide transport, defined as fPC,m/fI,m, and fSCN,m/fI,m, respectively, were 3.14 ± 1.20 and 0.27 ± 0.26 while PCT,in, SCNT,in, and IT,in among individuals varied 4.9, 5.0, and 8.4×, respectively. These transport selectivities are an order of magnitude lower than those indicated by in vitro ...

Journal ArticleDOI
25 Jun 2008-Thyroid
TL;DR: An attempt was made to calculate the average of dietary iodine intake from the consumption of seaweeds in Japan, and it was shown that households with elderly heads (>70 years) eat four times more Konbu than those with young heads (younger than 29 years).
Abstract: Since 1958 more than 100 papers on urinary iodine excretion have been published in Japan. Recent studies on the urinary iodine concentration in school children have shown median values of 288mg=L in Hokkaido (1) and 282 mg=L in Tokyo (2), but themaximumvaluewasmore than 3mg=L and 16% of the median values were> 1mg=L (2). In most of the earlier studies, daily urinary iodine excretion averaged from 1 to 20mg. It has been confirmed that urinary iodine excretion varies according to the quantity and frequency of seaweed consumption. Even in the same person, urinary iodine excretion could increase from 100 to 30,000mg=d within a day and decrease from 30,000 to 100mg=d within a few days (3). It is still not possible to report the average urinary iodine excretion in Japan, and in the World Health Organization (WHO) maps on urinary iodine excretion, values for Japan are still blank (4). A reliable answer is needed to the question ‘‘What is the average of iodine intake in Japan’’ or simply ‘‘What is the iodine intake in Japan’’. In this study, an attempt was made to calculate the average of dietary iodine intake from the consumption of seaweeds. Iodine content of seaweeds differ greatly according to species; Laminaria (Konbu) contains 0.3% of iodine by dry weight, Undaria (Wakame) 0.02–0.03%, and Porphyra (Nori) < 0.01%. Konbu was selected to calculate the average dietary iodine intake. The Family Income and Expenditure Survey by the Statistics Bureau, Ministry of Internal Affairs and Communications (5) included 8749 target households in 2006 and the survey included items pertaining to specific consumption, such as Konbu. The other method was to calculate iodine intake from the total consumption of Konbu in Japan using data obtained from the Japan Konbu Association (6). The average annual consumption of Konbu per household (two or more persons per household, average of 3.16 persons per household) in Japan is 450 g by dry weight, that is, 1.17mg of iodine per day per person. Consumption of Konbu per household has decreased gradually by 30% in the last 20 years; from 641 g in 1986 to 450 g in 2006. Consumption differs greatly according to the age of heads of households; < 29 years old, 145 g; 30–39 years old, 208 g; 40–49 years old, 315 g; 50–59 years old, 504 g; 60–69 years old, 561 g;> 70 years old, 616 g in 2006. Households with elderly heads (>70 years) eat four times more Konbu than those with young heads (younger than 29 years). It is also shown that consumption of Konbu in single-person households averages 567 g=y and differs according to age of the person, e.g.,< 34 years old, 54 g (male 18 g and female 112 g); 35–59 years old, 331 g (male 212 g and female 546 g); and> 60 years old 991 g (male 772 g and female 1082 g). Eighteen grams of Konbu per year is 150mg=d of iodine. Regional differences expressed as annual consumption of Konbu per household of two or more persons in cities with Prefectural Government is 517 200 g=y (mean and SD) and the range is from 241 g (0.6mg=d of iodine) in Miyazaki city to 1104 g (2.9mg=d of iodine) in Toyama city. According to the Japan Konbu Association, 95% of Konbu is produced in Hokkaido and 5% in the northern part of Honshu Island, and was distributed mainly on the Japan Sea side until the end of the 14th century. The Konbu road reached to Tokyo in the 17th–18th centuries (Fig. 1). Total consumption of Konbu in Japan is 20,000 tons per year by dry weight (6). Since the population of Japan is 130 million, the iodine intake by the ingestion of Konbu is 1.26mg=d per person. The results of methods numerically derived from independent two sources are remarkably similar and it may be concluded that the average of daily iodine intake through Konbu is about 1.2mg in Japan. Of course, iodine intake from Konbu is not the total iodine intake, but the answer to the question ‘‘What is the iodine intake in Japan’’ may be that excessive iodine intake in Japan is due to the ingestion of seaweeds especially Konbu and iodine intake by the seaweeds averaged 1.2mg=d in 2006. It should also be mentioned that the average intake of Konbu differs greatly according to age, family structure, and region. Adverse effects of Konbu ingestion was reported as costal goiter in one area of Hokkaido where the average daily intake of iodine fromKonbuwas 20mg=d (7). Ingestion of 10mg of iodine for 1 week in normal Japanese increased the response of thyrotropin in the thyrotropin releasing hormone test (8). When 30mg of iodinewas given daily to normal Japanese for 4 weeks, serum free thyroxine concentrations decreased and thyrotropin levels increased significantly, although within normal ranges, and the size of thyroids measured by echogram increased significantly. These abnormalities disappeared within 2 weeks after stopping iodide administration (9). Normal human thyroids can adapt to excess intake of iodide by autoregulation and pituitary–thyroid axis (10,11). It should be noted that the average of iodine excretion in Japan is not officially reported, and the Japan Thyroid Association is planning to measure urinary iodine excretion systematically throughout Japan. This study was presented in part at the 2007 American Thyroid Association meeting in New York (12).

Journal ArticleDOI
TL;DR: It is suggested that iodine/iodide may be useful as an adjuvant therapy in the pharmacologic manipulation of the estrogen pathway in women with breast cancer.
Abstract: The protective effects of iodine on breast cancer have been postulated from epidemiologic evidence and described in animal models. The molecular mechanisms responsible have not been identified but laboratory evidence suggests that iodine may inhibit cancer promotion through modulation of the estrogen pathway. To elucidate the role of iodine in breast cancer, the effect of Lugol's iodine solution (5% I(2), 10% KI) on gene expression was analyzed in the estrogen responsive MCF-7 breast cancer cell line. Microarray analysis identified 29 genes that were up-regulated and 14 genes that were down-regulated in response to iodine/iodide treatment. The altered genes included several involved in hormone metabolism as well as genes involved in the regulation of cell cycle progression, growth and differentiation. Quantitative RT-PCR confirmed the array data demonstrating that iodine/iodide treatment increased the mRNA levels of several genes involved in estrogen metabolism (CYP1A1, CYP1B1, and AKR1C1) while decreasing the levels of the estrogen responsive genes TFF1 and WISP2. This report presents the results of the first gene array profiling of the response of a breast cancer cell line to iodine treatment. In addition to elucidating our understanding of the effects of iodine/iodide on breast cancer, this work suggests that iodine/iodide may be useful as an adjuvant therapy in the pharmacologic manipulation of the estrogen pathway in women with breast cancer.

Journal ArticleDOI
14 Mar 2008-Thyroid
TL;DR: In this article, the authors found that iodine deficiency in infancy can impair neurocognitive development, but there are few available indicators of iodine intake during this critical period, and in many countries, access to new...
Abstract: Background: Iodine deficiency in infancy can impair neurocognitive development, but there are few available indicators of iodine intake during this critical period. In many countries, access to new...

Journal ArticleDOI
TL;DR: This study potentially provides a safe and organic iodine supplementation method to control IDD by raising the iodine content in vegetables by supplemented with iodized fertilizer.
Abstract: As a new attempt to control iodine deficiency disorder (IDD), we explored a method of iodine supplementation by raising the iodine content in vegetables. When grown in the soil supplemented with iodized fertilizer, the three experimental plant species (cucumber, aubergine, and radish) show increasing iodine levels in both leaf and fruit/rhizome tissues as the iodine content added in soil increases. Excessive iodine added to soil can be toxic to plants, whereas the tolerance limit to excessive iodine varies in the three plant species tested. The migration and volatilization of iodine in soil is correlated with the properties of the soil used. The residual iodine in soil increases as the iodine added to soil increases. The diatomite in the iodized fertilizer helps to increase the durability of the iodized fertilizer. This study potentially provides a safe and organic iodine supplementation method to control IDD.

Journal ArticleDOI
TL;DR: In this article, cyclic voltammetry at a platinum microelectrode at varying concentrations in the RTIL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C4mim][NTf2] has been investigated by using a digital simulation program.
Abstract: The electrochemical oxidation of 1-butyl-3-methylimidazolium iodide, [C4mim]I, has been investigated by cyclic voltammetry at a platinum microelectrode at varying concentrations in the RTIL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [C4mim][NTf2]. Two oxidation peaks were observed. The first peak is assigned to the oxidation of iodide to triiodide, in an overall two-electron process: 3I- − 2e- → I3-. At higher potentials, the electrogenerated triiodide oxidizes to iodine, in an overall one-electron process: I3- − e- → 3/2I2. An average diffusion coefficient, D, for I- of 1.55 × 10-11 m2 s-1 was obtained. A digital simulation program was used to simulate the voltammetric response, and kinetic parameters were successfully extracted. The parameters deduced from the simulation include D for I-, I3-, and I2 and Keq,2, the equilibrium constant for the reaction of iodide and iodine to form triiodide. Values for these parameters are of the same order as those previously published for the oxi...

Journal ArticleDOI
TL;DR: In this paper, the Potasasium iodide (KI)/air/sodium nitrite (NaNO 2 ; cat.)/sulfuric acid (H 2 SO 4 ) iodinating system was used for the selective and efficient iodization of organic compounds.
Abstract: Selective and efficient iodinations of organic compounds were achieved by an aerobic oxidative process catalyzed by sodium nitrite using potassium iodide in acidic media. Using the potasasium iodide (KI)/air/sodium nitrite (NaNO 2 ; cat.)/sulfuric acid (H 2 SO 4 ) iodinating system, activated and moderately deactivated aromatic compounds were exclusively or preferentially iodinated at the para position. In protic solvents ketones and 1,3-dicarbonyl compounds were iodofunctionalized at the a carbonyl position, while in the case of aryl methyl ketones bearing an activated aromatic ring, the regioselectivity of iodination could be directed by the solvent used. In acetonitrile (MeCN) the aromatic ring was selectively iodinated, while in aqueous rethanol (EtOH) functionalization of the methyl carbon atom took place. Alkenes were transformed to vicinal iodohydrins or vicinal iodoalkoxy derivatives following Markovnikov-type regioselectivity and anti stereoselectivity, while 1,2-diiodoalkenes with preferentially E orientation were formed from alkynes.

Journal ArticleDOI
TL;DR: Iodine uptake by Chinese cabbage was more effective than in the form of I− if the concentration was low, but the trend was opposite if iodine concentration was 0.5 mg L−1 or higher, which implies that the uptake mechanism transits from active to passive as the iodine concentration increases.
Abstract: Iodine-enhanced vegetable has been proven to be an effective way to reduce iodine deficiency disorders in many regions. However, the knowledge about what mechanisms control plant uptake of iodine and where iodine is stored in plants is still very limited. A series of controlled experiments, including solution culture, pot planting, and field experiments were carried out to investigate the uptake mechanism of iodine in different forms. A new methodology for observing the iodine distribution within the plant tissues, based on AgI precipitation reaction and transmission electron microscope techniques, has been developed and successfully applied to Chinese cabbage. Results show that iodine uptake by Chinese cabbage was more effective when iodine was in the form of IO(3) (-) than in the form of I(-) if the concentration was low (<0.5 mg L(-1)), but the trend was opposite if iodine concentration was 0.5 mg L(-1) or higher. The uptake was more sensitive to metabolism inhibitor in lower concentration of iodine, which implies that the uptake mechanism transits from active to passive as the iodine concentration increases, especially when the iodine is in the form of IO(3) (-). The inorganic iodine fertilizer provided a quicker supply for plant uptake, but the higher level of iodine was toxic to plant growth. The organic iodine fertilizer (seaweed composite) provided a more sustainable iodine supply for plants. Most of the iodine uptake by the cabbage is intercepted and stored in the fibrins in the root while the iodine that is transported to the above-ground portion (shoots and leaves) is selectively stored in the chloroplasts.

Journal ArticleDOI
Hong Chunlai1, Huan-Xin Weng1, Ya-Chao Qin1, Ai-Lan Yan1, Ling-Li Xie1 
TL;DR: In this paper, the authors studied the transfer of iodine from soil to vegetables using both inorganic iodine (KI) and organic, seaweed iodine (OI) and found that the iodine levels in vegetables increase with the increasing addition of iodine.
Abstract: Iodine deficiency disorders are one of the commonest preventable human health problems. Producing iodine-enriched crops could be an effective way to reduce their epidemicity in many regions. However, the actual knowledge on this issue is limited mostly to studies involving grain crops and inorganic iodine fertilizers such as I− and IO 3 − . Moreover, the translocation, transformation and distribution of iodine from soil to plants are not well understood. Here, we studied iodine transfer from soil to vegetables using both inorganic iodine (KI) and organic, seaweed iodine. Greenhouse culture experiments were undertaken to assess the absorption and accumulation of iodine by four vegetables: Chinese cabbage, lettuce, tomato and carrot. We also investigated the dynamic variation of exogenous iodine in soil by applying KI and a composite of seaweed and diatomite. Our results show first that iodine levels in vegetables increase with the increasing addition of iodine. Second, the iodine content in the edible portion ranks as follows: Chinese cabbage (high I) > lettuce > carrot > tomato (low I). The iodine accumulation in the edible portion of the cabbage is thus 2.25 and 4.45 times higher than that of lettuce and carrot, respectively, and 19.67 times higher than that of tomato. In vegetable tissues the iodine distribution is ranked as: root (high I) > leaf > stem > fruit (low I), except for carrot, where the average iodine level in the rhizome is 50% of the shoot. Third, vegetable growth is inhibited when the added iodine concentration is higher than 50 mg kg−1. The order of tolerance against iodine toxicity is ranked as: carrot (high tolerance) > Chinese cabbage > lettuce > tomato (low tolerance). Fourth, the seaweed composite iodine fertilizer demonstrates more potential of durability than KI. Indeed, when KI is added to the soil at 150 mg kg−, the biomass of cabbage, lettuce, tomato and carrot decreases by 34.8%, 41.3%, 46.8% and 17.9%, respectively. By comparison, the biomass decreases are lower, 16.6%, 22.9%, 23.4% and 9.7%, respectively, when applying the seaweed composite. Fifth, after harvest, the residual iodine in soil fertilized with KI is only 56% of the initial addition, which is less than that for seaweed composite. This study is of theoretical importance to understand iodine biogeochemistry and its transfer behavior, and also has practical implications for seeking effective alternatives of iodine biofortification to prevent iodine deficiency disorders.

Journal ArticleDOI
TL;DR: Given identical iodine delivery rates of 1.3 g/s and iodine loads of 33 g, contrast media with concentrations of 300, 370 and 400 mg iodine/ml do not result in different intravascular enhancement in chest-CT.
Abstract: In computed tomography(CT) several contrast media with different iodine concentrations are available The aim of this study is to prospectively compare contrast media with iodine concentrations of 300, 370 and 400 mg iodine/ml for chest- CT 300 consecutive patients were prospectively enrolled, under a waiver of the local ethics committee The first (second, third) 100 patients, received contrast medium with 300(370, 400)mg iodine/ml Injection protocols were adapted for an identical iodine delivery rate(13 mg/s) and total iodine load(33 g) for all three groups Standardized MDCT of the chest (16 × 075 mm, 120 kVp, 100 mAseff) was performed Intravascular attenuation values were measured in the pulmonary trunk and the ascending aorta; subjective image quality was rated on a 3-point-scale Discomfort during and after injection was evaluated There were no statistically significant differences in contrast enhancement comparing the three contrast media at the pulmonary trunk(p = 03198) and at the ascending aorta(p = 00840) Image quality(p = 00176) and discomfort during injection(p = 07034) were comparable for all groups General discomfort after injection of contrast media with 300 mg iodine/ml was statistically significant higher compared to 370 mg iodine/ml(p = 000019) Given identical iodine delivery rates of 13 g/s and iodine loads of 33 g, contrast media with concentrations of 300, 370 and 400 mg iodine/ml do not result in different intravascular enhancement in chest-CT

Journal ArticleDOI
TL;DR: In this article, it was shown that Iodate reacts with natural organic matter (NOM) producing either hypoiodous acid (HIO) or I2 as an intermediate.
Abstract: Previous studies have shown that iodine (including 129I) can be strongly retained in organic-rich surface soils and sediment and that a large fraction of soluble iodine may be associated with dissolved humic material. Iodate (IO3−) reacts with natural organic matter (NOM) producing either hypoiodous acid (HIO) or I2 as an intermediate. This intermediate is subsequently incorporated into the organic matter. Based on reactions of model compounds, we infer that iodine reacts with peat by aromatic substitution of hydrogen on phenolic constituents of the peat. Alternatively, the intermediate, HIO or I2, may be reduced to iodide (I−). The pH (and temperature) dependence of the IO3− reaction (reduction) has been explored with sphagnum peat, alkali lignin, and several model compounds. The incorporation of iodine into NOM has been verified by pyrolysis gas chromatography/mass spectrometry (GC/MS). Model compound studies indicate that reduction of IO3− to HIO may result from reaction with hydroquinone (or semiquinone) moieties of the peat.

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TL;DR: In this article, the morphological transformation process resulting from the reaction between Au nanorods (NRs) and iodine in situ produced from the redox between potassium iodide and copper chloride was monitored by virtue of the transmission electron microscope (TEM) images and the plasmon resonance absorption (PRA) spectra.
Abstract: The morphological transformation process resulting from the reaction between Au nanorods (NRs) and iodine in situ produced from the redox between potassium iodide and copper chloride was monitored by virtue of the transmission electron microscope (TEM) images and the plasmon resonance absorption (PRA) spectra. It was found that the presence of copper chloride or potassium iodide could make the longitudinal PRA band of Au-NRs shift without any change of morphological transformation owing to the change of the refractive index of the medium. Different from that, iodine, which was in situ produced from the redox of potassium iodide and copper chloride, could fuse Au-NRs in the side-by-side mode, resulting in morphological transformation of Au-NRs to sphericity with the characteristics of the decrease of aspect ratio, blue-shift of the longitudinal PAR band, red-shift of transverse PRA band, and broadening of both longitudinal and transverse PRA bands of Au-NRs. The blue-shifted wavelength of the longitudinal ...

Journal ArticleDOI
TL;DR: In this article, the influence of storage conditions on the stability of potassium iodide (KI) stability was evaluated by determining iodine retention during storage, and the results showed that the storage of iodised table salt resulted in iodine content decrease and the iodine losses in the salt tended to increase at high humidity or unlimited access of air.
Abstract: Summary To determine the influence of storage conditions on potassium iodide (KI) stability, its traditional carrier – iodised table salt and alternative collagen carriers (i.e. iodinated collagen fibre and collagen hydrolysate) were stored at high (90%) and medium (60%) relative humidity of air. At medium humidity, these carriers were additionally stored at limited and unlimited access of air. The stability of KI was estimated by determining iodine retention during storage. The obtained results showed that the storage of iodised table salt resulted in iodine content decrease. The iodine losses in the salt tended to increase at high humidity or unlimited access of air. However, application of collagen preparations as carriers increased the KI stability, reducing iodine losses during storage and making them independent on the storage conditions.

Journal ArticleDOI
TL;DR: 4-Iodopiperidines are prepared in good yields and with high selectivity by means of aza-Prins-cyclization using a catalytic amount of gallium(III) iodide and a stoichiometric amount of iodine under mild reaction conditions.

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TL;DR: The diffusion coefficients of triiodide in binary mixtures of ionic liquids at 25 ± 0.05 °C were determined via steady-state cyclic voltammetry at platinum disk microelectrodes in five different electrolyte systems, all representing potential ionic liquid based electrolytes for dye-sensitised solar cells.
Abstract: The diffusion coefficients of triiodide in binary mixtures of ionic liquids at 25 ± 0.05 °C were determined via steady-state cyclic voltammetry at platinum disk microelectrodes in five different electrolyte systems, all representing potential ionic liquid based electrolytes for dye-sensitised solar cells. These electrolytes were composed of iodine, 1-methyl-3-propylimidazolium iodide (acting as iodide source) and a second lower viscous ionic liquid, namely 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium tetrafluoroborate or 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and were investigated either at fixed ionic liquid composition and varying iodine concentration or at fixed iodine concentration and varying 1-methyl-3-propylimidazolium iodide content. To check and optimise our measurement set-up, four Pt disk microelectrodes with four different electrode radii (0.3–5 µm) were tested at a well known system (ferrocene/tetraethylammonium tetrafluoroborate/acetonitrile solutions). The radius of each electrode was controlled by scanning electron microscopy at the beginning and during the work.

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TL;DR: The iodine status of neonates in Denmark is influenced by regional variations and dependency on maternal iodine supplementation, as well as the gender and ethnic make-up of the parents.
Abstract: Iodine status of 147 neonates born in five different regions of Denmark was evaluated in relation to the iodine content of breast milk and iodine supplementation taken by the mother. Approximately two-thirds of the women had not received iodine supplementation. They had low iodine concentrations in breast milk and urinary iodine concentrations of the neonates at day 5 were low. The median values (milk/urine) were 33.6/31.7 micrograms/l (Randers 22/26, Ringkobing 29/16, Aalborg 36/31. Arhus 54/41 and Copenhagen 55/59 micrograms/l). Higher values were found in the group where tablets containing iodine had been taken (milk/urine: 57.0/61.0 micrograms/l). In general, the values are low compared with internationally recommended levels. We suggest that mothers without autoimmune thyroid disease should receive iodine supplementation in the form of vitamin/mineral tablets containing iodine (150 micrograms per tablet).

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TL;DR: The fraction available suggests an importance of drinking water supply for population iodine Intake, although this may not be adequate to estimate population iodine intake.
Abstract: Iodine intake is important for thyroid function. Iodine content of natural waters is high in some areas and occurs bound in humic substances. Tap water is a major dietary source but bioavailability of organically bound iodine may be impaired. The objective was to assess if naturally occurring iodine bound in humic substances is bioavailable. Tap water was collected at Randers and Skagen waterworks and spot urine samples were collected from 430 long-term Randers and Skagen dwellers, who filled in a questionnaire. Tap water contained 2mg/l elemental iodine in Randers and 140mg/l iodine bound in humic substances in Skagen. Median (25; 75 percentile) urinary iodine excretion among Randers and Skagen dwellers not using iodine-containing supplements was 50 (37; 83) mg/24h and 177 (137; 219) mg/24h respectively (P,0·001). The fraction of samples with iodine below 100mg/24h was 85·0% in Randers and 6·5% in Skagen (P,0·001). Use of iodine-containing supplements increased urinary iodine by 60mg/24h (P,0·001). This decreased the number of samples with iodine below 100mg/24h to 67·3% and 5·0% respectively, but increased the number of samples with iodine above 300mg/24h to 2·4% and 16·1%. Bioavailability of iodine in humic substances in Skagen tap water was about 85%. Iodine in natural waters may be elemental or found in humic substances. The fraction available suggests an importance of drinking water supply for population iodine intake, although this may not be adequate to estimate population iodine intake. Iodine bioavailability: Humic substances: Drinking water: Population-based study

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TL;DR: The iodine intake of newborns is entirely dependent on the iodine content of breast milk and the formula preparations used to feed them, and an inadequate iodine supply (deficiency and excess) might be especially dangerous in the case of premature babies.

Journal ArticleDOI
12 Feb 2008-Genomics
TL;DR: Analysis of the transcriptome profile of the rat follicular cell lineage PCCl3 under untreated and treated conditions with 10(-3) M sodium iodide shows that both the oxidized form of iodide and iodide per se are responsible for gene expression modulation in response to iodide excess.