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Author(s): Dmytro Rafalskyi [sup.1] , Javier Martínez Martínez [sup.1] , Lui Habl [sup.1] [sup.2] , Elena Zorzoli Rossi [sup.1] , Plamen Proynov [sup.1] , Antoine Boré [sup.1] , Thomas Baret [...], Propulsion is a critical subsystem of many spacecraft.sup.1-4. For efficient propellant usage, electric propulsion systems based on the electrostatic acceleration of ions formed during electron impact ionization of a gas are particularly attractive.sup.5,6. At present, xenon is used almost exclusively as an ionizable propellant for space propulsion.sup.2-5. However, xenon is rare, it must be stored under high pressure and commercial production is expensive.sup.7-9. Here we demonstrate a propulsion system that uses iodine propellant and we present in-orbit results of this new technology. Diatomic iodine is stored as a solid and sublimated at low temperatures. A plasma is then produced with a radio-frequency inductive antenna, and we show that the ionization efficiency is enhanced compared with xenon. Both atomic and molecular iodine ions are accelerated by high-voltage grids to generate thrust, and a highly collimated beam can be produced with substantial iodine dissociation. The propulsion system has been successfully operated in space onboard a small satellite with manoeuvres confirmed using satellite tracking data. We anticipate that these results will accelerate the adoption of alternative propellants within the space industry and demonstrate the potential of iodine for a wide range of space missions. For example, iodine enables substantial system miniaturization and simplification, which provides small satellites and satellite constellations with new capabilities for deployment, collision avoidance, end-of-life disposal and space exploration.sup.10-14. The successful in-orbit operation of an electric space propulsion system based on iodine, rather than the more expensive and difficult-to-store xenon, is demonstrated.

High strength polyvinyl alcohol (PVA) fibers with a conventional degree of polymerization of 1500 were prepared by doping iodine with PVA spinning solution. The iodine-doped PVA (I-PVA) aqueous solution was extruded into cold methanol that provides dark purple PVA-iodine complex gel fibers. Only a small amount of iodine was required to enhance drawability and molecular orientation by reducing the interaction between PVA chains. An increase of ca. 10% in the maximum draw ratio of the doped fibers compared with that of undoped PVA translated into values for the tensile strength, 2.2 Giga-Pascal (GPa), and initial modulus (47 GPa) that were more than 30% higher than those of the neat PVA fiber. Easier chain slippage of molecules in the amorphous segments of the I-PVA fiber during drawing leads to increased orientation in these segments, which is believed to be the source of the improvements in mechanical properties. POLYM. ENG. SCI., 51:647-653, 2011. [C] 2010 Society of Plastics Engineers, INTRODUCTION Polyvinyl alcohol (PVA) is a water-soluble and environmentally friendly synthetic polymer with a broad range of industrial and technical applications, especially in fiber-reinforced concrete (FRC). PVA reinforces the strength, [...]

A study is conducted to determine whether radioiodine treatment is associated with increased mortality and also the influences of mild thyroid dysfunction and the development of overt hypothyroidism treated with throxine (T4). It is concluded that patients treated with radioiodine for hyperthyroidism had increased mortality vs age- and period-specific mortality in England and Wales, a finding no longer evident during T4 therapy.

Byline: Julia Langgartner (1), Hans-Jorg Linde (2), Norbert Lehn (2), Michael Reng (1), Jurgen Scholmerich (1), Thomas Gluck (1) Keywords: Skin disinfection; Chlorhexidine; Propanol; Povidone-iodine; Central venous catheter; Infection; Bacterial colonisation Abstract: Objective Central venous catheter (CVC)-related infections may be caused by micro-organisms introduced from the skin surface into deeper tissue at the time of CVC insertion. The optimal disinfection regimen to avoid catheter-related infections has not yet been defined. This study compares three different approaches. Design Prospective randomised trial. Setting A tertiary care hospital. Patients and participants One hundred nineteen patients scheduled electively to receive 140 CVCs. Interventions Skin disinfection was performed with either povidone-iodine 10% (PVP-iodine), chlorhexidine 0.5%/propanol 70%, or chlorhexidine 0.5%/propanol 70% followed by PVP-iodine 10%. Prior to disinfection, a swab from the site of insertion was taken for culture. CVCs were removed if no longer needed or infection was suspected. All catheters were cultured quantitatively after removal. Measurement and results Bacteria could be isolated from 20.7% of the catheter tips. Bacterial growth was found in 30.8% of the catheters placed after skin disinfection with povidone-iodine, in 24.4% after disinfection with propanol/chlorhexidine and in 4.7% after disinfection with propanol/chlorhexidine followed by povidone-iodine (p=0.006). In 15 cases, the same organism was isolated from the skin swab and the catheter tip. Ten of these paired isolates showed the same pattern in a pulsed-field gel electrophoresis analysis. Conclusions Skin disinfection with propanol/chlorhexidine followed by PVP-iodine was superior in the prevention of microbial CVC colonisation compared to either of the regimens alone. These results support the concept that catheter infections can originate from bacterial translocation at the time of catheter insertion. Author Affiliation: (1) Department of Internal Medicine I, University Medical Centre, University of Regensburg, 93042, Regensburg, Germany (2) Institute of Medical Microbiology and Hygiene, University Medical Centre, University of Regensburg, 93042, Regensburg, Germany Article History: Registration Date: 12/03/2004 Received Date: 30/07/2003 Accepted Date: 11/03/2004 Online Date: 15/04/2004

A vitamin C clock activity uses supermarket/drugstore chemicals, including tincture of iodine, hydrogen peroxide, and liquid laundry starch, optional orange juice, and widely available equipment. The activity can be used to explore reaction kinetics and especially the effect of reactant concentrations on the apparent rate of a reaction. It can be useful in the descriptive chemistry of iodine, a discussion of redox chemistry, and the chemistry of vitamin C. The endpoint is signaled by an abrupt change in the appearance of the reaction solution from colorless to blue-black. Explanatory article includes data and discussion.

The explanation of multistability, a basic problem for understanding the phenomena, has not been presented for students although nonlinear phenomena such as oscillating chemical reactions and chaos are shown pedagogically in various places. A simplified model is given with possible steady states of the system shown in 3-D space. The concentration of three species that can be monitored experimentally are plotted along three axes. Topics include the Bray-Liebhafsky oscillatory reaction and multistability within that model.

Rapid, simple quantitation can be carried out in thin-layer chromatography (TLC) by using a flatbed scanner attached to an ordinary computer. TLC is much used for qualitative analysis in undergraduate organic chemistry laboratories and others, but not much used for quantitation because the plate scanner and spotters are too expensive. TLC is valuable as a separation process because of simultaneous, multisample capability, speed, and availability of almost universal visualization techniques. Cholesterol and cholesteryl esters stained with iodine can be used.

The use of the azide group as a mobile ligands was examined. The technique would create haloazide-like species under much milder conditions, namely, in an organic solvent, than commonly applied. (Diacetoxyiodo)benzene was reacted with tetraethylammonium bromide in dichloromethane at room temperature. Novel reagent systems that are readily generated in situ from bisazido iodo benzene and tetraalkylammonium halides are described.

Iodinated analogs of nonsteroidal antiinflammatory drugs (NSAIDs), iodosuprofen and iodoindomethacin, inhibit the cyclooxygenase activity of the membrane protein, prostaglandin H2 synthase. The inhibitors bind at the end of the long channel that leads to the active site and prevent access of substrate to Tyr-385 which is necessary for catalytic action. Space-filling models indicate that the NSAIDs are buried deep in the enzyme and produce conformational changes on attachment. The synthesis and characterization of the iodinated analogs is discussed.

A laser-induced iodine fluorescence-based approach for the planar measurements of temperature, pressure, density, velocity and injectant mole fraction is presented. The scheme uses iodine instead of a tunable dye laser to excite the absorption transition line of a compressible, highly three-dimensional turbulence flow. Iodine has been found to be more capable of producing accurate planar imaging of fluorescence than laser. Experiments involving a flowfield of Mach two flow validates the applicability of the proposed scheme.

Unprotected aldoses have undergone oxidative amidation with functionalized amines, [alpha]-amino esters and peptides, whereas KDO, sialic acid and other [alpha]-keto acids have proceeded with oxidative decarboxylation followed by in situ amidation when iodine is used as an appropriate oxidant. Glycoside bond and many other functional groups are inert under mild conditions and this reaction protocol for direct ligation of carbohydrate molecules is useful in the development of a general synthesis of glycoconjugates.

Iodine was discovered in by Bernard Courtois in 1811 when he was working on seaweed ash. An experiment that follows Courtois' isolation of iodine from seaweeds is described. The experiment engages student's interest in the history of elements and teaches them on the uses of redox reactions.

The synthetic utility of organohypervalent iodine reagents are illustrated by their use in the alpha-hydroxydimethylacetal formation reaction from enolizable ketones, alpha-hydroxylation, alpha-tosyloxylation, alpha-alkoxylation, carbon-carbon bond formation, and intermolecular cyclopropanation using iodonium ylides. The uses of these reagents in the Hunsdiecker reaction of carboxylic acids and Hofmann rearrangement of carboxamides are presented.

The 'beta-modification' attempts to produce large single crystals of ZrSb2 by using iodine as chemical transport agent. It reveals that 'beta-ZrSb2 does not exist as written but rather it is a ternary zirconium silicide antimonide (ZrSi(sub delta)Sb(sub 2-delta)) crystallizing in the TiNiSi type.

Molecular beam epitaxy (MBE) grown Hg0.80Cd0.20Te(112)B is shown to have the highest mobilities and close to a minimum density of voids when a Hg/Te flux ratio of approximately 180 is employed. Electron concentration is proportional to that of iodine with a 100% electrical activation for concentration up to approx. 10(super 18) cm(super -3).

Research was conducted to investigate the detritylation of ethers using iodine-alcohol reagents through an acid-catalyzed reaction. Results demonstrate that 1% solutions of iodine in methanol readily removed trityl and dimethoxytrityl ether groups in good yield and selectively. Trityl groups were transformed to trityl methyl ether and triphenylmethane but triphenylmethanol is also formed when the methanol is wet.

A laboratory exercise using iodine and sulfur to demonstrate melting point depression is geared toward first-year inorganic chemistry students. Iodine and sulfur are inorganic compounds that are widely available, cost-effective, and easy to dispose of after use. In addition, the melting points of these compounds are below 120 degrees celsius. This allows the use of economical equipment for melting point measurements. Procedures for the experiment are outlined.

Recent evidence has revealed that the use of iodinated agents like gadolinium-based agents is associated with a risk of nephrogenic systemic fibrosis (NSF), which has only been reported in patients with kidney disease. Details of the research carried out to better understand the pathogenesis of NSF by Thomas Hope, a resident in radiology at the University of California, San Francisco and colleagues on rats is highlighted.