Iodine Compounds

An incorrect rate constant for sulfite radical anion recombination of 2k 6 ) 1.4 × 10 8 dm 3 mol -1 s -1 15 was given under eq 6. The correct value is 2k 6 ) 1.4 × 10 9 dm 3 mol -1 s -1 . 15 The derived rate constants reported in this paper are unchanged, as the correct value was used in the fitting procedure. JP9616831

Unfortunately, Courtois could not follow up on his research of this new substance because of economic hardship. However, he managed to incite two of his chemist friends, Charles Bernard Desormes and Nicolas ClØment, to pursue the studies-together with AndrØ M. Ampre and Joseph Louis Gay-Lussac. ClØment presented the findings on Courtois behalf to the Imperial Institute of France (Conservatoire des Arts et MØtiers, where he held a professorship) on November 29, 1813, which resulted in their original

Coronary artery angiography remains an important procedure for the assessment of coronary arteries. It requires injection of iodinated contrast for the opacification of coronary arteries. Severe allergy to iodine contrast and renal insufficiency are two main problems with iodine-based contrast media. Gadolinium (Gd) has different chemical structure with no cross reactivity with iodine-based contrast media in patients with iodine allergy. The use of Gd is commonly used in contrast-enhanced magnetic resonance imaging for image enhancement, making it a potential alternative in patients in whom iodine is contraindicated. The aim of this manuscript is to review the available literature on the use of Gd in patients with contraindication to iodine contrast due to allergy or in patients with severe renal failure requiring coronary or vascular procedures. V

Steady-state and time-resolved fluorescence techniques were used to study the behavior of 2 I ,3 I -O-(o-xylylene)per-O-Me-R-and -β-cyclodextrins in aqueous solution, based on the fluorescence of the bidentate xylylene moiety. Fluorescence decay profiles obtained upon excitation of the xylylene group were fitted to threeexponential decay functions. In addition to a fast component due to stray and/or scattered light, two other components ascribed to the monomer and dimer species, respectively, were identified. The dimer/monomer ratio increases with concentration and decreases with temperature, which is in agreement with an enthalpydriven association process. The corresponding dimerization equilibrium constants (K D ) were obtained from nonlinear regression analysis of the plots of 〈τ〉 against [CD] in the 5-45 °C range. A linear van't Hoff analysis for K D allows us to obtain the ∆H and ∆S associated to dimer formation. Molecular mechanics as well as molecular dynamics calculations in the presence of water were also employed to study the conformational behavior of such secondary-face-substituted cyclodextrins and rationalize the dimerization processes.

Background and objectives: Human chorionic gonadotropin (HCG) and thyrotrophic hormone (TSH) have analogies in their structures, as well as in their receptors. The high levels of HCG seen in gestational trophoblastic diseases may induce secondary hyperthyroidism. The objective of this report was to present a case in which the administration of iodinated contrast triggered a thyrotoxic crisis. Case report: Patient with complete hydatidiform mole who was admitted to the operating room with severe vaginal bleeding after a tomographic exam with iodinated contrast. During anesthetic induction, the patient presented symptoms compatible with thyrotoxic crisis. The incidence of severe presentations associated with gestational trophoblastic disease tends to decrease with early diagnosis. Still, the anesthesiologist should be aware of the possibility of those patients developing thyrotoxic crisis.

Background and objectives: Human chorionic gonadotropin (HCG) and thyrotrophic hormone (TSH) have analogies in their structures, as well as in their receptors. The high levels of HCG seen in gestational trophoblastic diseases may induce secondary hyperthyroidism. The objective of this report was to present a case in which the administration of iodinated contrast triggered a thyrotoxic crisis. Case report: Patient with complete hydatidiform mole who was admitted to the operating room with severe vaginal bleeding after a tomographic exam with iodinated contrast. During anesthetic induction, the patient presented symptoms compatible with thyrotoxic crisis. The incidence of severe presentations associated with gestational trophoblastic disease tends to decrease with early diagnosis. Still, the anesthesiologist should be aware of the possibility of those patients developing thyrotoxic crisis.

Table 3. Mixed Treatment comparison results (including summary of iGrade estimate quality -high, moderate, low or very low) Cochrane Library Trusted evidence. Informed decisions. Better health. Preoperative skin antiseptics for preventing surgical wound infections a er clean surgery (Review)

Iodinated contrast agents have been in use since the 1950s to facilitate radiographic imaging modalities. Physicians in almost all specialties will either administer these agents or care for patients who have received these drugs. Different iodinated contrast agents vary greatly in their properties, uses, and toxic effects. Therefore, clinicians should be at least superficially familiar with the clinical pharmacology, administration, risks, and adverse effects associated with iodinated contrast agents. This primer offers the non-radiologist physician the opportunity to gain insight into the use of this class of drugs.

Iodinated contrast agents have been in use since the 1950s to facilitate radiographic imaging modalities. Physicians in almost all specialties will either administer these agents or care for patients who have received these drugs. Different iodinated contrast agents vary greatly in their properties, uses, and toxic effects. Therefore, clinicians should be at least superficially familiar with the clinical pharmacology, administration, risks, and adverse effects associated with iodinated contrast agents. This primer offers the non-radiologist physician the opportunity to gain insight into the use of this class of drugs.

Background: Iodine deficiency is a major public health problem in many developing countries including Nepal. The present study was designed to investigate the urinary iodine excretion (UIE), thyroid function status and household salt iodine content (SIC) in school-aged children (SAC) and to establish the relationships between these factors. Methods: A community-based cross sectional study was conducted in selected schools of two districts, Tehrathum and Morang, lying in the hill and plain region of eastern Nepal respectively. A total of 640 SAC, (Tehrathum n = 274 and Morang n = 366) aged 6-11 years, were assessed for UIE and household SIC. Among the 640 children, 155 consented to blood samples (Tehrathum n = 78 and Morang n = 77) to test for serum thyroglobulin (Tg), thyroid stimulating hormone (TSH), free triiodothyronine (fT 3) and free thyroxine (fT 4). UIE was measured by ammonium persulfate digestion method. SIC was measured by iodometric titration method and Tg, TSH, fT 4 and fT 3 were measured by immunoassay based kit method. Results: In Tehrathum and Morang, 9.5 and 7.7 % of SAC had UIE values of UIE <100 µg/L while 59.5 and 41 % had iodine nutrition values of >299 µg/L, with median UIE of 345.65 and 270.36 µg/L respectively. The overall medians were as follows, Tg 14.29 µg/L, fT 3 3.94 pmol/L, fT 4 16.25 pmol/L and TSH 3.61 mIU/L. There was a negative correlation between UIE and Tg (r = −0.236, p = 0.003) and a positive correlation between UIE and SIC (r = 0.349, p < 0.0001). We found 19.5 %, n = 15 and 16.7 %, n = 13 subclinical hypothyroid cases in Morang and Tehrathum respectively. Iodometric titration showed only 6.4% (n = 41) of the samples had household SIC <15 ppm. Multivariate analysis revealed that use of packaged salt by SAC of Tehrathum district correlated with higher UIE values. Conclusions: Our focused data suggests that collaborative universal salt iodization (USI) programs are improving the health of children in the Tehrathum and Morang districts of Nepal. We also found that excessive iodine in a large portion of the study groups is a substantial concern and iodine intervention programs need to deal with both deficient and excessive iodine scenarios that can both be present simultaneously in study populations.

Objective To determine whether the amount of tagged stool and fluid significantly affects the radiation exposure in lowdose screening CT colonography performed with an automatic tube-current modulation technique. Methods The study included 311 patients. The tagging agent was barium (n=271) or iodine (n=40). Correlation was measured between mean volume CT dose index (CTDI vol ) and the estimated x-ray attenuation of the tagged stool and fluid (ATT). Multiple linear regression analyses were performed to determine the effect of ATT on CTDI vol and the effect of ATT on image noise while adjusting for other variables including abdominal circumference. Results CTDI vol varied from 0.88 to 2.54 mGy. There was no significant correlation between CTDI vol and ATT (p = 0.61). ATT did not significantly affect CTDI vol (p=0.93), while abdominal circumference was the only factor significantly affecting CTDI vol (p<0.001). Image noise ranged from 59.5 to 64.1 HU. The p value for the regression model explaining the noise was 0.38. Conclusion The amount of stool and fluid tagging does not significantly affect radiation exposure.

Micro-computed tomography (micro-CT) has been widely used to generate high-resolution 3-D tissue images from small animals nondestructively, especially for mineralized skeletal tissues. However, its application to the analysis of soft cardiovascular tissues has been limited by poor inter-tissue contrast. Recent ex vivo studies have shown that contrast between muscular and connective tissue in micro-CT images can be enhanced by staining with iodine. In the present study, we apply this novel technique for imaging of cardiovascular structures in canine hearts. We optimize the method to obtain high-resolution X-ray micro-CT images of the canine atria and its distinctive regions-including the Bachmann's bundle, atrioventricular node, pulmonary arteries and veins-with clear inter-tissue contrast. The imaging results are used to reconstruct and segment the detailed 3-D geometry of the atria. Structure tensor analysis shows that the arrangement of atrial fibers can also be characterized using the enhanced micro-CT images, as iodine preferentially accumulates within Manuscript

A conspicuous feature of modern synthetic organic chemistry is the impressive proliferation of new reagents. Recently, D. H. R. Barton made the point that 20 years ago a synthetic chemist could function perfectly adequately using perhaps twenty synthetic reactions.' The tremendous increase in the application of organometallics to synthetic methodology has changed, certainly for the better, that rather complacent situation. This Account deals with the synthetic use of a class of compounds recently termed "organometallic" reagents2 This is an apt description because many of the reaction pathways of hypervalent iodine are formally similar to those of organometallic chemistry. Hypervalent or higher valent iodine compounds have a long history in organic chemistry. In fact 1986 marks the centenary of the discovery of (dich1oroiodo)benzene (1) by Willger~dt.~ In 1914 Willgerodt published a lengthy review summarizing the considerable amount of work done by him.4 This may have been a case in science in which his review was so comprehensive that people concluded that all that was worth knowing was known. At any rate very little systematic work was done in this area with the exception of studies by F. M. Beringer in the period 1950-19705 and Neilands and co-workers in Russia during the same periode6 A key date in the development of this field is 1969 when J. I. Musher published a review titled "The Chemistry of Hypervalent Molecules" and, in fact, introduced the term "hypervalency".' Musher was concerned with the bonding in molecules such as C6H51C12 (1) in which the Lewis-Langmuir theory of valence could not accommodate "expanded octet" molecules. The term hypervalency refers to "molecules or ions formed by elements in Group V-VI11 of the periodic table in any valence state other than their lowest stable chemical valence of 3, 2, 1, or 0, respectively. We refer tQ these molecules as hypervalent since they involve donor atoms which exceed the number of valences by traditional theory and thus utilize more electron-pairs of bonding than provide stability in the Lewis-Langmuir theory." Thus C6H510, C6H5102, CF31F2, CF31F4, C6H51F6, and C6H51C(C02Et)2 are examples of molecules containing hypervalent iodine according to the Musher definition. Bonding in a molecule such as CGH,IC1, (1) uses essentially pure p orbitals in the linear Cl-I-C1 system. This is a three-center four-electron bond with two electrons from the doubly occupied 5p orbital on iodine Robert M. Moriarty received his Ph.D. degree from Princeton University in 1959 and did postdoctoral work with R. Huisgen in 1960 and with E. J. Corey in 1961. His research interests are in synthetic and mechanistic organic chemistry. Om Prakash received his Ph.D. degree from the University of Roorkee in 1976 and has been a postdoctoral co-worker at UIC since 1983. H e was appointed to the post of lecturer (assistant professor) at Kurukshetra University, Kurukshetra, India in 1986. His research interests are in the areas of synthetic and physical organic chemistry.

The expanding use of imaging and interventional studies with iodinated radiologic contrast agents underscores the potential risk for dye nephropathy. Currently, dye-induced nephropathy is one of the leading causes of iatrogenic acute kidney failure, accounting for about 10% of renal failure in intensive care units. In this review, the pathophysiology of radiocontrast nephropathy is discussed, with a special emphasis on the importance of medullary hypoxic damage. The risk factors and clinical course of dye nephropathy, as well as its prevention or potential therapeutic interventions, are discussed in this perspective.

Objective To review the efficacy of pharmacological prevention of serious reactions to iodinated contrast media. Design Systematic review. Data sources Systematic search (multiple databases, bibliographies, all languages, to October 2005) for randomised comparisons of pretreatment with placebo or no treatment (control) in patients receiving iodinated contrast media. Review methods Trial quality was assessed by all investigators. Information on trial design, population, interventions, and outcomes was abstracted by one investigator and cross checked by the others. Data were combined by using Peto odds ratios with 95% confidence intervals. Results Nine trials (1975-96, 10 011 adults) tested H 1 antihistamines, corticosteroids, and an H 1 -H 2 combination. No trial included exclusively patients with a history of allergic reactions. Many outcomes were not allergy related, and only a few were potentially life threatening. No reports on death, cardiopulmonary resuscitation, irreversible neurological deficit, or prolonged hospital stays were found. In two trials, 3/778 (0.4%) patients who received oral methylprednisolone 2×32 mg or intravenous prednisolone 250 mg had laryngeal oedema compared with 11/769 (1.4%) controls (odds ratio 0.31, 95% confidence interval 0.11 to 0.88). In two trials, 7/3093 (0.2%) patients who received oral methylprednisolone 2×32 mg had a composite outcome (including shock, bronchospasm, and laryngospasm) compared with 20/2178 (0.9%) controls (odds ratio 0.28, 0.13 to 0.60). In one trial, 1/196 (0.5%) patients who received intravenous clemastine 0.03 mg/kg and cimetidine 2-5 mg/kg had angio-oedema compared with 8/194 (4.1%) controls (odds ratio 0.20, 0.05 to 0.76). Conclusions Life threatening anaphylactic reactions due to iodinated contrast media are rare. In unselected patients, the usefulness of premedication is doubtful, as a large number of patients need to receive premedication to prevent one potentially serious reaction. Data supporting the use of premedication in patients with a history of allergic reactions are lacking. Physicians who are dealing with these patients should not rely on the efficacy of premedication. Extra references are on bmj.com

Carrier diffusion is imaged in a perovskite film and crystal using a newly developed transient absorption microscope. Wide-field imaging is combined with a diffractive optic-based beam geometry to conduct 41 transient absorption experiments in parallel in this experimental setup. This configuration allows statistics to be quickly compiled with a 1 kHz laser system. Diffusion coefficients of 0.01 and 0.20 cm 2 /s are obtained for the methylammonium lead iodide film and crystal, respectively. Our data suggest that the dynamics in the film are dominated by intensity dependence of the carrier lifetimes as opposed to carrier diffusion. The small diffusion coefficients determined in the film are attributed to the presence of grain boundaries.

This study shows that iodinated organic compounds can be produced when iodide-containing waters are in contact with manganese oxide birnessite (δ-MnO 2) in the pH range of 5-7. In the absence of natural organic matter (NOM), iodide is oxidized to iodate that is also adsorbed onto δ-MnO 2. In the presence of iodide and NOM, adsordable organic iodine compounds (AOI) are formed at pH <7 because of the oxidation of iodide to iodine by δ-MnO 2 and the reactions of iodine with NOM. In addition, iodoacetic acid and iodoform have been identified as specific iodinated byproducts. Formation of iodoform is not observed for high NOM/δ-MnO 2 ratios due to inhibition of the catalytic effect of δ-MnO 2 by NOM poisoning. Experiments with model compounds such as resorcinol and 3,5heptanedione confirmed that the δ-MnO 2 /Isystem is very effective for the formation of iodinated organic compounds. These results suggest that birnessite acts as a catalyst through the oxidation of iodide to iodine and the polarization of the iodine molecule, which then reacts with NOM moieties. Furthermore, our results indicate that during water treatment in the presence of manganese oxide, iodinated organic compounds may be formed, which may lead to taste and odor or toxicological problems.

This study shows that iodinated organic compounds can be produced when iodide-containing waters are in contact with manganese oxide birnessite (δ-MnO 2) in the pH range of 5-7. In the absence of natural organic matter (NOM), iodide is oxidized to iodate that is also adsorbed onto δ-MnO 2. In the presence of iodide and NOM, adsordable organic iodine compounds (AOI) are formed at pH <7 because of the oxidation of iodide to iodine by δ-MnO 2 and the reactions of iodine with NOM. In addition, iodoacetic acid and iodoform have been identified as specific iodinated byproducts. Formation of iodoform is not observed for high NOM/δ-MnO 2 ratios due to inhibition of the catalytic effect of δ-MnO 2 by NOM poisoning. Experiments with model compounds such as resorcinol and 3,5heptanedione confirmed that the δ-MnO 2 /Isystem is very effective for the formation of iodinated organic compounds. These results suggest that birnessite acts as a catalyst through the oxidation of iodide to iodine and the polarization of the iodine molecule, which then reacts with NOM moieties. Furthermore, our results indicate that during water treatment in the presence of manganese oxide, iodinated organic compounds may be formed, which may lead to taste and odor or toxicological problems.

Aim The aim of this study was to evaluate the antibacterial effect of iodine-potassium iodide (IKI) and calcium hydroxide (CH) on dentinal tubules infected with Enterococcus faecalis (E. faecalis) at different time intervals. Methods and Materials Hollow cylinders of bovine root dentin (n=45) were infected and divided into three equal groups filled with either IKI or CH and a positive control. After placing each medicament in the infected cylinders for time periods of 10 minutes, 48 hours and 7 days, microbiological samples were analyzed. At the end of each period, four 100 μm thick inner dentin layers (400 μm thick from each specimen) were removed using dental burs of increasing diameters. Dentin powder was cultured on agar plates to quantitatively assess their infection, expressed in colony forming units (cfu). Results In all layers of the positive control group, heavy bacterial infection was observed. After 10 minutes, IKI reduced the amount of viable bacteria more efficiently th...

ABSTRACTContinued development of a system designed to grow crystals by physical vapor transport in the environment of Spacelab III will be described, with special emphasis on simulation of expected space conditions, adjustment of crystal growth parameters, and on board observation and control of the experiment by crew members and ground personnel.A critical factor in the use of mercuric iodide for semiconductor detectors of x-rays and gamma-rays is the crystalline quality of the material. The twofold purpose of the Spacelab III experiment is therefore to grow single crystals with superior electronic properties as an indirect result of the greatly reduced gravity field during the growth, and to obtain data which will lead to improved understanding of the vapor transport mechanismThe experiments planned to evaluate the space crystals, including gamma-ray diffractometry and measurements of stoichiometry, lattice dimensions, mechanical strength, luminescense, and detector performance wi...

Iodine deficiency disorders (IDD) still represent a major public health problem, with almost 30% of the world population being exposed to the consequences of nutritional iodine deficiency (ID). In Italy, despite a sustained policy of iodine prophylaxis, more than 10% of people is still affected with goiter, and a presumably higher rate of subjects may suffer from minor cognitive deficits due to inadequate iodine supply during antenatal life. This review of systematic observational studies carried out over thirty-five years (1980-2015) in a sentinel ID area in North-eastern Sicily highlights the changing phenotypes of IDD in this region. Over the years profound improvements in nutritional iodine status in North-eastern Sicily has occurred, due to both silent and active iodine prophylaxis. Endemic cretinism, resulting from severe iodine deficiency, has been progressively replaced by less serious deficits of intellectual and cognitive abilities, which nevertheless deserve proper attention.

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

Hypervalent (HV) iodine(III) compounds with fluorine-containing ligands (F, CF 3 , C 6 F 5 CO 2 , or CF 3 (CF 2) 8 CO 2 (n-C 9 F 19 CO 2)) reacted, in the presence of iodine or copper salts, with the double bonds in cis-1,4-polyisoprene (polyIP) to afford fluorine-containing polymers. For instance, fast iodo-fluorination of polyIP was accomplished in the presence of 4-(difluoroiodo)toluene (4-TolIF 2) and iodine. The reaction of polyIP with 1-trifluoromethyl-1,2-benziodoxol-3(1H)-one (Togni reagent II) and copper(I) iodide under mild conditions yielded polymers with vicinal pendant trifluoromethyl and 2-iodobenzoate groups, which were subjected to acid-promoted elimination to give a fluorine-containing unsaturated polymer. The simultaneous introduction of trifluoromethyl groups and a halogen (Cl or Br) was achieved by reacting polyIP with Togni reagent II in the presence of thionyl halide and copper(II) salts. The alkyl chloride pendant groups in the product of the copper-mediated reaction of polyIP with thionyl chloride and Togni reagent II were subsequently converted to azide functionalities by nucleophilic substitution with NaN 3 , and the produced azide-containing polymer was subjected to copper(I)catalyzed "click" coupling reaction with a fluorescent alkyne, propargyl 4-(1-pyrenyl)butyrate. Perfluoroacyloxy pendant groups were also introduced successfully by the reaction of polyIP with HV iodine(III) reagents with perfluorinated carboxylate ligands, i.e., C 6 H 5 I(O 2 CC 6 F 5) 2 and C 6 H 5 I(O 2 C(n-)C 9 F 19) 2 , in the presence of iodine. No significant chain degradation and/or cross-linking was observed in any of the functionalization reactions. The modified polymers showed relatively good thermal stability and high hydrophobicity, with contact angles toward water in the range of 89−116°.

The potential use of three Metal−Organic Frameworks (MIL−53(Al), MIL−120(Al) and HKUST−1(Cu)) to adsorb iodine species (I 2 and ICH 3), which can be released during a severe nuclear accident, is investigated using periodic dispersion density functional theory for the first time. Competitive adsorption of iodine in the presence of water molecules is also characterized for the hydrophilic HKUST−1(Cu). In the first step, we have found that the absolute values of interaction energies of I 2 and ICH 3 are higher in the hydrated form of HKUST−1(Cu) than in the dehydrated one, which is of very high interest for iodine trapping. In a second stage, iodine species are strongly adsorbed in MIL−53(Al) compared to MIL−120(Al) and HKUST−1(Cu) MOFs and therefore this material could potentially trap iodine compounds. Moreover, we study the influence of the functionalization of the MIL−53(Al) organic linkers on the adsorption behavior of iodine and it turns out that the substitutions does not present a significant effect for this purpose. The factors governing the interaction energies between iodine (I 2 and ICH 3) and MOF structures are analyzed and the important role of van der Waals interactions in these materials is highlighted.

The complexes of iodine with six polynuclear aromatic hydrocarbons have been prepared. The thermodynamic stability of these complexes was studied by vaporization techniques and solid-state electrochemical cells. The vapor pressure of iodine over the complexes at temperatures of 550-950 were determined by a colorimetric measurement of iodine vapor. Heats of formation of the complexes were estimated from the data.

The majority of halogenated organic compounds present in the environment remain unidentified. To address this data gap, we recently developed an untargeted method (data-independent precursor isolation and characteristic fragment; DIPIC-Frag) for identification of unknown organobromine compounds. In this study, the method was adapted to enable untargeted screening of natural and synthetic organo-iodine compounds (NSOICs) in sediments. A total of 4,238 NSOIC peaks were detected in sediments from Lake Michigan. Precursor ions and formulas were determined for 2,991 (71%) of the NSOIC peaks. These compounds exhibited variations in abundances (<10 3 to ∼10 7), m/z values (206.9304−996.9474), retention times (1.0−29.7 min), and number of iodine atoms (1−4). Hierarchical cluster analysis showed that sediments in closer proximity exhibited similar profiles of NSOICs. NSOICs were screened in 10 samples of sediment from the Arctic Ocean to compare the profiles of NSOICs between freshwater and marine sediments. A total of 3,168 NSOIC peaks were detected, and profiles of NSOICs in marine sediments were clearly distinct from Lake Michigan. The coexistence of brominated and iodinated analogues indicated that some NSOICs are of natural origin. Different ratios of abundances of iodinated compounds to brominated analogues were observed and proposed as a marker to distinguish sources of NSOICs.

The modern concepts on specific features of anisotropy of the electron density of valence shells of bound atoms and chemical bonds providing the successful description of the proper ties of halogen bonds formed by the iodine molecule in compounds with useful physicochemi cal properties are generalized in the review. The prognoses of basicity by the diiodine basicity scale for the nitrogen containing compounds are illustrated. The regularities and peculiari ties of shifting bands in Raman spectra of iodine containing organic crystals are considered. The methodical and specific problems of modeling appeared when the electronic characteris tics of the iodine compounds are estimated and briefly discussed.

The chemical conversion of Ag 2 O films on Ag surfaces to AgI in aqueous iodide solutions has been studied electrochemically. Ag 2 O films were grown potentiostatically and then exposed to I − solutions. The chemical conversion process was followed at open-circuit potential ͑E OC ͒ using cathodic stripping voltammetry performed after various exposure periods. The E OC showed a sudden drop at the completion of the conversion of Ag 2 O to AgI, reaching a steady-state value close to the equilibrium potential for AgI/Ag and the iodide solution. This sudden drop in E OC allowed easy determination of the total reaction time required for complete conversion of Ag 2 O to AgI. Distinctly separated current peaks were observed for the cathodic reduction of Ag 2 O and AgI to Ag, and the charges associated with these peaks provided a measure of the amount of Ag 2 O converted. The conversion reaction was 100% efficient. The total reaction times from the E OC measurements and the cathodic stripping results were used to determine the reaction order and rate constant required for the development of nuclear reactor safety assessment codes.

A series of compounds possessing polyvalent iodine groups was prepared from onitroiodobenzene. Single crystal X-ray investigation revealed a strong interaction between iodine atom and one of the oxygen atoms of the nitro group. This interaction is strongest in trifluoroacetate of hydroxy(o-nitrophenyl)iodonium salt, which is formed from an iodosylarene and an acid being the first example of this new class of compounds. These compounds are also characterized by NMR-spectroscopy.

The antimicrobial efficacy of endodontic procedures performed in one-visit (including a 10-min intraappointment dressing with 5% iodine-potassium-iodide) was compared with a two-visit procedure (including an interappointment dressing with calcium-hydroxide paste). Teeth with apical periodontitis (n ‫؍‬ 96) were randomly assigned to either group. Root canal sampling and culturing were performed before and immediately after instrumentation, and after medication. Initial sampling demonstrated the presence of microorganisms in 98% of the teeth. Postinstrumentation sampling showed reduction of cultivable microbiota. Antibacterial dressing further reduced the number of teeth with surviving microbes. In the postmedication samples, residual microorganisms were recovered in 29% of the one-visit teeth and in 36% of the two-visit treated teeth. No statistically significant differences between the groups were discerned. It was concluded that from a microbiological point of view, treatment of teeth with apical periodontitis performed in two appointments was not more effective than the investigated one-visit procedure.

RS-4-(4-Hydroxyphenyl)-2-butanol (rhododendrol, RD) was reported to induce leukoderma of the skin. To explore the mechanism underlying that effect, we previously showed that oxidation of RD with mushroom tyrosinase produces RD-quinone, which is converted to secondary quinone products, and we suggested that those quinones are cytotoxic because they bind to cellular proteins and produce reactive oxygen species. We then confirmed that human tyrosinase can oxidize both enantiomers of RD. In this study, we examined the metabolism of RD in B16F1 melanoma cells in vitro. Using 4-amino-3-hydroxy-n-butylbenzene as a specific indicator, we detected moderate levels of RD-pheomelanin in B16F1 cells exposed to 0.3 to 0.5 mM RD for 72 h. We also confirmed the covalent binding of RD-quinone to non-protein thiols and proteins through cysteinyl residues. The covalent binding of RD-quinone to proteins was 20- to 30-fold greater than dopaquinone. These results suggest that the tyrosinase-induced metab...

Neuromelanin (NM) is produced in dopaminergic neurons of the substantia nigra (SN) and in noradrenergic neurons of the locus coeruleus (LC). The synthesis of NM in those neurons is a component of brain aging and there is the evidence that this pigment can be involved in the pathogenesis of neurodegenerative diseases such as Parkinson&#39;s disease. NM is believed to derive from the oxidative polymerization of dopamine (DA) or norepinephrine (NE) with the participation of cysteine, dolichols and proteins. However, there are still unknown aspects in the chemical structure of NM from SN (SN-NM) and LC (LC-NM). In this study, we designed a new method to synthesize o-aminophenol compounds as putative degradation products of catecholamines and their metabolites which may be incorporated into NM. Those compounds are aminohydroxyphenylethylamine (AHPEA) isomers, aminohydroxyphenylacetic acid (AHPAA) isomers and aminohydroxyethylbenzene (AHEB) isomers, which are expected to arise from DA or ...

A sensitive and specific high performance liquid chromatography (HPLC) method was developed to quantify 4‐amino‐3‐hydroxyphenylalanine (4‐AHP) and 3‐amino‐4‐hydroxyphenylalanine (3‐AHP) in urine. In degradation studies of melanin pigment, 4‐AHP and 3‐AHP are derived from benzothiazine units of pheomelanin and pheomelanin‐related metabolites such as trichochromes. 5‐S‐Cysteinyldopa‐derived benzothiazine products give 4‐AHP while 2‐S‐cysteinyldopa‐derived benzothiazine products give 3‐AHP. 3‐AHP is also derived from nitrotyrosine formed by nitration of tyrosine with reactive nitrogen species. For this reason, the influence of this biological process on the amount of 3‐AHP found in biological material have been investigated. The method is based on hydriodic acid hydrolysis of the melanin polymer and reversed‐phase HPLC with electrochemical detection of the degradation products 4‐AHP and 3‐AHP. The mobile phase consists of 25 mM ammonium acetate and sodium octanesulfonate as an ion‐pair...

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

ONTRAST-INDUCED NEPHROPAthy, which occurs in 1% to 15% of all patients undergoing invasive angiographic procedures and in as many as 50% of patients with preexisting renal insufficiency or diabetes mellitus, is one of the most common causes of hospitalacquired acute renal failure. 1-7 The development of contrast-induced nephropathy after diagnostic coronary angiography and percutaneous intervention is associated with prolonged hospitalization, marked increases in morbidity and early and late mortality, and costs. 4-8 Other than hydration, 9,10 most prior studies of measures to prevent contrast-induced nephropathy have either been neutral, 11 found deleterious effects, 12-15 or in the case of N-acetylcysteine, reported conflicting results. 16-19

BACKGROUND AND PURPOSE: Several studies suggest that various types of cellular therapies enhance recovery after stroke in animal models. IA-based delivery of cells to the brain is under investigation for stroke, but it is unknown whether cells are injured as a result of being injected through a catheter or exposed to iodinated contrast medium or solutions containing heparin. MATERIALS AND METHODS: We assessed the effect of catheterization with the Excelsior SL-10 catheter or exposure to heparin or iodine contrast on human bone marrow MNCs. Viability and cell injury were assessed by trypan blue exclusion, caspase-3 activity, and lipid peroxidation. Cellular function of MNCs was assessed by their production and release of VEGF, IL-10, and IGF-1. RESULTS: Flow rates of 10 million cells from 0.5 to 2 mL/min did not alter MNC viability; however, 5 mL/min of MNCs did reduce viability by 19%. Iodine and low-dose heparin exposure did not affect cell viability; however, high-dose heparin was cytotoxic. Catheter delivery at 2 mL/min did not affect levels of VEGF, IL-10, or IGF-1. CONCLUSIONS: MNCs do not appear to be damaged by heparin, iodine contrast, and the Excelsior SL-10 catheter at flow rates up to 2 mL/min. However, higher flow rates did reduce viability, and high-dose heparin did cause cell death. ABBREVIATIONS: Cath-Hypo ϭ hypoxia; DMEM ϭ Dulbecco's Modified Eagle's Medium; ELISA ϭ enzyme-linked immunosorbent assay; FDA ϭ US Food and Drug Administration; H.D. ϭ high dose; H-Hypox ϭ MNCs not catheterized but conditioned; IA ϭ intra-arterial; IGF-1 ϭ insulin-like growth factor 1; IL-10 ϭ interleukin 10; L.D. ϭ low dose; MNC ϭ mononuclear cell; N-Cath ϭ nonconditioned MNCs; N-Cont ϭ MNCs not catheterized; O.D. ϭ optical density; PBS ϭ phosphate-buffered saline; VEGF ϭ vascular endothelial growth factor

Physical properties such as photoconductivity, dielectric and thermal stability have been investigated for pure benzoyl glycine (BG) crystals. In addition to this, the influence of dopants (benzophenone and iodine) of these properties on BG crystals has been studied. Photoconductivity studies on pure BG, benzophenone-and iodine-doped BG revealed the positive photoconducting nature. The dielectric responses of the samples have been studied in the frequency range 100 Hz-500 KHz at room temperature and the results are discussed in detail. The thermogravimetric studies of pure and doped BG crystals indicate that the presence of dopants has slightly increased the decomposition temperature of pure BG samples, thereby enhancing thermal stability to the doped ones.

Trihalophenols, which are drinking water disinfection byproducts (DBPs) formed by chlorination or chloramination practices, can be biomethylated into trihalogenated anisoles. These latter compounds have traditionally been suspected of causing odor episodes in drinking water around the world. The odor threshold concentration (OTC) of mixed chlorobrominated anisoles, which were previously synthesized, was determined by flavor profile analysis (FPA) performed by an experienced panel trained to identify odors and tastes in water. The odor threshold amount (OTA) was evaluated by using a gas chromatograph equipped with olfactometry (GC-O) and electron capture detectors (ECD). FPA results for mixed chlorobromoanisoles gave a theoretical OTCs range from 2 to 30 ng/L, the 2,6-diBr-3Cl-anisole being the most odorous compound. Rubber is the general descriptor described by panelists for these compounds, although earthy and musty are the following most cited descriptors.

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

Five-membered heterocycles are well known for their innate nucleophilicity. In contrast, reaction of these heterocycles as electrophiles is less established and has become only recently an intensively investigated research area in synthetic chemistry. The use of hypervalent iodine reagents for the umpolung of the nucleophilic reactivity has been especially successful. This review provides a comprehensive overview regarding the generation of electrophilic intermediates from electron-rich heterocycles using hypervalent iodine reagents. The functionalization with different heteroatoms, arenes or heteroarenes nucleophiles is then described.

Hypervalent iodine compounds have enjoyed a very rich chemistry in recent years. Many novel reactions have been developed, and new reagents as well as strategies have expanded the repertoire of the synthetic chemist. [1] Hypervalent bromine compounds, however, have not been considered seriously although they have been known for a long time. Already in 1952 the formation of the diazonium salt from amine 1 and subsequent thermal decomposition yielding the l 3-bromane derivative 2 was described (Scheme 1). [2]

Perovskite solar cells represent a highly promising third-generation photovoltaic technology. However, their practical implementation is hindered by low device operational stability, mostly related to facile degradation of the absorber materials under exposure to light and elevated temperatures. Improving the intrinsic stability of complex lead halides is a big scientific challenge, which might be addressed using various “molecular modifiers”. These modifiers are usually represented by some additives undergoing strong interactions with the perovskite absorber material, resulting in enhanced solar cell efficiency and/or operational stability. Herein, we present a derivative of 1,4,6,10-tetraazaadamantane, NAdCl, as a promising molecular modifier for lead halide perovskites. NAdCl spectacularly improved both the thermal and photochemical stability of methylammonium lead iodide (MAPbI3) films and, most importantly, prevented the formation of metallic lead Pb0 as a photolysis product. N...