Abstract  Titania-supported gold nanoparticles were prepared by using the deposition-precipitation method, followed by reduction under a hydrogen flow. The catalytic activity of these as-prepared catalysts was explored in the oxidation of cellobiose to gluconic acid with molecular oxygen, and the properties of these catalysts were examined by using XRD, TEM, temperature-programmed desorption of NH3, energy-dispersive X-ray spectroscopy, UV/Vis, and X-ray photoemission spectroscopy (XPS). The catalyst sample reduced at high temperature demonstrated an excellent catalytic activity in the oxidation of cellobiose. The characterization results revealed the strong metal-support interaction between the gold nanoparticles and titania support. Hydrogen reduction at higher temperatures (usually >600 degrees C) plays a vital role in affording a unique interface between gold nanoparticles and titania support surfaces, which thus improves the catalytic activity of gold/titania by fine-tuning both the electronic and structural properties of the gold nanoparticles and titania support.

Abstract  The formation of volatile compounds in fresh cheese by 10 Enterobacteriaceae strains of dairy origin (4 Hafnia alvei, 2 Serratia liquefaciens, 1 Enterobacter cloacae, 1 Enterobacter sakazakii, and 2 Escherichia coli strains) was investigated. Small cheeses were made from pasteurized cow's milk separately inoculated with 1-3 x 10(3) CFU/ml of each of the Enterobacteriaceae strains, with glucono-8-lactone added to achieve a pH value of 5.2 in the curds. All strains reached counts close to 10(8) CFU/g in 1-day-old cheeses and survived well from day 1 to day 8. Cheeses were analyzed for volatile compounds by gas chromatography-mass spectroscopy, after extraction by dynamic headspace using a purge and trap apparatus. Sixty-one volatile compounds were determined in cheeses, 31 of which were further investigated. Significant increases of aldehydes, sulfur compounds, and aromatic compounds were recorded from 2-h curd to 1-day-old cheese, and of ketones, alcohols, and acids from 2-h curd to 8-day-old cheese. Acetaldehyde, 2-methyl propanal, and 3-methyl butanal predominated among aldehydes; 2,3-butanedione, 2,3-pentanedione, and 3-hydroxy 2-butanone among ketones; ethanol, 2-methyl propanol, and 3-methyl butanol among alcohols; and ethyl acetate among esters. Hierarchical cluster analysis of strains using the data of 31 volatile compounds separated clearly the strain of E. sakazakii, which produced high amounts of volatile compounds, from the other Enterobacteriaceae strains.

Abstract  Sorbents for high temperature CO2 capture are under intensive development owing to their potential applications in advanced zero emission power, sorption-enhanced steam methane reforming for hydrogen production and energy storage systems in chemical heat pumps. One of the challenges in the development is the prevention of sintering of the sorbent (normally a calcium oxide derivative) which causes the CO2 capture capacity of the material to deteriorate rapidly after a few cycles of utilization. Here we show that a simple wet mixing method can produce sintering-resistant sorbents from calcium and magnesium salts of d-gluconic acid. It was found that calcium oxide was well distributed in the sorbents with metal oxide nanoparticles on the surface acting as physical barriers, and the CO2 capture capacity of the sorbents was largely maintained over multiple cycles of utilization. This method was also applied to other organometallic salts of calcium and magnesium/aluminum and the produced sorbents showed similarly high reversibility.

Abstract  Endogenous enteric nitric oxide has multiple functions. Enteric nitric oxide may be diminished in the premature infant and may therefore predispose the immature intestine to injury. The aim of this study was to determine if the infusion of a nitric oxide donor (nitroglycerin) would attenuate intestinal damage in a rabbit model of necrotizing enterocolitis. Transmural injection of rabbit intestinal loops with an acidified solution of casein and calcium gluconate simulates certain aspects of necrotizing enterocolitis. After injection of acidified casein solution into rabbit intestinal loops, twelve rabbits were randomly divided into two groups: six received maintenance fluids only and six received maintenance fluids and a nitroglycerin infusion adjusted to maintain mean arterial pressure 10 mm Hg below baseline (range, 2 to 12 micrograms/kg/min). After 3 hours, the rabbits were killed, and the intestinal tissue graded histologically. Intestinal damage in the nitroglycerin-treated rabbits was significantly less than that of untreated controls (mean histological grade of 0.39 v 1.48, P < .001). In this rabbit model of necrotizing enterocolitis, infusion of the nitric oxide donor nitroglycerin significantly attenuates intestinal damage. We speculate that enteric nitric oxide deficiency, as may exist in the preterm infant, predisposes the intestine to necrotizing enterocolitis.

Abstract  A simplified kiet has been developed for 99mTc protein radiolabeling using an N3S triamide mercaptide bifunctional chelating agent and the preformed chelate approach. The process combined N3S chelating agent, gluconate intermediate transfer agent, stannous reducing agent, and gentisic acid stabilizer into a lyophilized formulation. With sulfur donor atom hemithioacetal protection of the ligand, delta-2,3,5,6-tetrafluorothiophenyl alpha-S-(1-ethoxyethyl)mercaptoacetamido-L-adipoylglycylglycine , optimum 99mTc chelation was achieved in a single step. Subsequent reaction with NR-LU-10 antibody Fab fragment followed by purification via QAE Sephadex anion exchange resin filter afforded 99mTc-N3S-NR-LU-10 Fab conjugate with retained immunoreactivity and effective tumor targeting properties.

Abstract  The mechanism responsible for the transport of the glutathione-methylmercury complex (CH3HgSG) across liver canalicular membranes into bile was investigated. Uptake of radiolabeled CH3HgSG by canalicular liver plasma membranes (cLPM) isolated from Sprague-Dawley-rats was dependent upon time and temperature. To reduce nonspecific binding of the complex by the membrane, S-(2,4-dinitrophenyl)glutathione was included in the test solutions. Increasing internal medium osmolarity and extrapolation to infinite osmolarity indicated that 50% of the measured complex in cLPM was due to nonspecific membrane binding. Uptake of the CH3HgSG complex was not affected by the replacement of a sodium-chloride gradient with gradients of potassium-chloride or lithium-chloride. Addition of ATP had no effect on CH3HgSG uptake. A significant increase in CH3HgSG uptake was detected when valinomycin was included in an external medium containing 100 millimolar (mM) potassium-gluconate. Uptake of tritiated glutathione (GSH) was also increased under these conditions. Concentration dependent increases in the initial rates of CH3HgSG uptake followed Michaelis-Menten kinetics for substrate concentrations from 5 micromolar to 5 millimolar. Uptake of the CH3HgSG complex was inhibited by GSH, its S-methyl, S-ethyl, S-butyl, S-hexyl, S-octyl, and S-dinitrophenyl conjugates as well as by ophthalmic acid. Uptake was not effected by oxidized glutathione (GSSG), bile acids, amino acids or P-glycoprotein inhibitors. Competitive inhibition of CH3HgSG uptake by GSH was demonstrated by kinetic studies. Preloading of cLPM with CH3HgSG or GSH significantly increased uptake of CH3HgSG. The authors conclude that CH3HgSG and GSH share canalicular transport carriers that are responsible for the elimination of methylmercury (22967926) via bile excretion.

Abstract  The present work consisted in the study of the oxidation Yield induced by catalysts during ozonation of sodium gluconate, toluene sulfonic acid and Triton X100 in dilute aqueous solution (TOC = 8 mg C/L). Two operating conditions have been used to demonstrate the enhancement brought about by catalytic ozonation: continuous filtration experiments and batch tests.

Dynamic filtration experiments have been performed on catalysts previously saturated to simulate the behavior of the catalyst over a long period of use.

Batch experiments which allowed us to distinguish the part due to adsorption, ozonation and catalytic effect were carried out on three catalysts with intent to test their efficiency. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

Abstract  AIMS: To study phosphate solubilization in Penicillium purpurogenum as function of medium pH, and carbon and nitrogen concentrations.

METHODS AND RESULTS: Tricalcium phosphate (CP) solubilization efficiency of P. purpurogenum was evaluated at acid or alkaline pH using different C and N sources. Glucose- and (NH(4) )(2) SO(4) -based media showed the highest P solubilization values followed by fructose. P. purpurogenum solubilizing ability was higher in cultures grown at pH 6·5 than cultures at pH 8·5. Organic acids were detected in both alkaline and neutral media, but the relative percentages of each organic acid differed. Highest P release coincided with the highest organic acids production peak, especially gluconic acid. When P. purpurogenum grew in alkaline media, the nature and concentration of organic acids changed at different N and C concentrations. A factorial categorical experimental design showed that the highest P-solubilizing activity, coinciding with the highest organic acid production, corresponded to the highest C concentration and lowest N concentration.

CONCLUSIONS: The results described in the present study show that medium pH and carbon and nitrogen concentrations modulate the P solubilization efficiency of P. purpurogenum through the production of organic acids and particularly that of gluconic acid. In the P solubilization optimization studies, glucose and (NH(4) )(2) SO(4) as C and N sources allowed a higher solubilization efficiency at high pH.

SIGNIFICANCE AND IMPACT OF THE STUDY: This organism is a potentially proficient soil inoculant, especially in P-poor alkaline soils where other P solubilizers fail to release soluble P. Further work is necessary to elucidate whether these results can be extrapolated to natural soil ecosystems, where different pH values are present. Penicillium purpurogenum could be used to develop a bioprocess for the manufacture of phosphatic fertilizer with phosphate calcium minerals.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Aluminum (Al), one of the most widespread element on earth, often contaminates preparations such as parenteral nutrition solutions. Small-volume additives such as calcium gluconate and phosphate salts solutions are the most contaminated. Large-volume parental source solutions such as dextrose, crystalline amino acids and lipid emulsions are significantly less contaminated. Premature infants generally need intravenous feeding and are therefore vulnerable to aluminum toxicity: protective gastrointestinal mechanisms are bypassed and renal function is immature. Several studies showed that Al blood levels and urinary excretion increase when premature infants received parenteral nutrition. Urinary elimination is not adequate and Al accumulation is observed in tissues, especially in bones. Recently, in preterm infants, prolonged intravenous feeding with solutions containing Al was demonstrated to be associated with impaired neurologic development. Montreuil Hospital intensive c

Abstract  The anodic behaviour of Al in gluconic acid (HG) solutions was studied. Al was found to pit in such solutions. Surface and cross-sectional views of the SEM images recorded beyond the breakdown potential (E(b)) revealed the occurrence of intense pitting attack with the formation of large hemispherical pits. The effect of adding some environmentally acceptable inorganic inhibitors (tungstates, molybdates or silicates) on the pitting corrosion behaviour of Al in HG solutions was also studied. Measurements were carried out under the influence of various experimental variables based on polarization and chronoamperometric techniques. These measurements were complemented by ex situ scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations of the electrode surface. The presence of these compounds in HG solutions decreased the passive current density (j(pass)) and increased Eb. In HG solutions, chronoamperometric measurements showed that the anodic current density first decreased, due to growth of a passive oxide film, then increased withme after a pit incubation time, t(i) and finally attained a steady-state value. Value of t(i) was shortened and simultaneously the steady-state current was elevated, corresponding to an increase in the rate of pit initiation and growth, with increasing applied anodic potential and HG concentration. The rate of pit nucleation (t(i)(-1)) was found to decrease to an extent depending on the type and concentration of the introduced inhibitor. The inhibitory effect of these compounds decreased in the order: Si(2)O(5)(2-) > WO(4)(2-) > WO(4)(2-) > MoO(4)(2-). (C) 2010 Elsevier Ltd. All rights reserved.

Abstract  HEEP COPYRIGHT: BIOL ABS. NOTE HUMAN CALCIUM GLUCONATE ALUMINUM SALTS CALCIUM EDTA SERPENTINE BORON IRON METABOLIC-DRUG ANTIDOTE OSTEO POROSIS

Abstract  Although cell-free biosystems have been used as a tool for investigating fundamental aspects of biological systems for more than 100 years, they are becoming an emerging biomanufacturing platform in the production of low-value biocommodities (e.g., H(2), ethanol, and isobutanol), fine chemicals, and high-value protein and carbohydrate drugs and their precursors. Here we would like to define the cell-free biosystems containing more than three catalytic components in a single reaction vessel, which although different from one-, two-, or three-enzyme biocatalysis can be regarded as a straightforward extension of multienzymatic biocatalysis. In this chapter, we compare the advantages and disadvantages of cell-free biosystems versus living organisms, briefly review the history of cell-free biosystems, highlight a few examples, analyze any remaining obstacles to the scale-up of cell-free biosystems, and suggest potential solutions. Cell-free biosystems could become a disruptive technology to microbial fermentation, especially in the production of high-impact low-value biocommodities mainly due to the very high product yields and potentially low production costs.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. A multinational interlaboratory study to investigate the bovine corneal opacity and permeability (BCOP) assay is presented. The aim of this work was to determine the capability and possible limitations of this method to predict ocular irritancy of a large set of chemicals. The assays were carried out in 12 European laboratories with different types of activity. In each of these laboratories 52 substances, with a wide range of structure, physical form and irritant properties, were tested and in vitro scores were compared with those obtained from concurrent rabbit eye (Draize) tests. The technique was easily learned by workers in the participating laboratories, as shown by the fact that there were consistent responses between treated corneas within an individual laboratory. Interlaboratory variability was also very good. It was found that a given laboratory had a 96% chance of classifying irritants or non-irritants similarly to the other laboratories. In addition, it was

Abstract  The aim of this work was to characterize and to quantify ozonation by-products of glucose in ultrapure water ([Glucose](o) = 5 mmol 1(-1); initial pH : pH approximate to 6, final pH : approximate to 3). HPLC and GC analyses showed that ozonation of glucose yields mainly gluconic acid (0.6 - 0.7 mole I mole of glucose eliminated) and formic acid (0.2 - 0.25 mole / mole of glucose eliminated) at the beginning of the reaction. Glycolic acid, formaldehyde and peroxides were also formed for low ozone dosages. GC/MS analyses carried out on extracts from ozonated solutions of glucose and gluconic acid (90-95% removal of the initial organic compound) allowed the identification of several by-products wih six carbon atoms (hexosuloses, glucuronic and glucaric acids) and with less carbon atoms (acids and aldehydes).

Abstract  Effects of several Cl(-) channel blockers on ionic currents in mouse embryos were studied using whole-cell patch-clamp and microelectrode methods. Microelectrode measurements showed that the resting membrane potential of early embryonic cells (1-cell stage) was -23 mV and that reduction of extracellular Cl(-) concentration depolarized the membrane, suggesting that Cl(-) conductance is a major contributor for establishing the resting membrane potential. Membrane currents recorded by whole-cell voltage clamp showed outward rectification and confirmed that a major component of these embryonic currents are carried by Cl(-) ions. A Cl(-) channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), suppressed the outward rectifier current in a voltage- and concentration-dependent manner. Other Cl(-) channel blockers (5-nitro-2-[3-phenylpropyl-amino] benzoic acid and 2-[3-(trifluoromethyl)-anilino] nicotinic acid [niflumic acid]) similarly inhibited this current. Simultaneous application of niflumic acid with DIDS further suppressed the outward rectifier current. Under high osmotic condition, niflumic acid, but not DIDS, inhibited the Cl(-)current, suggesting the presence of two types of Cl(-) channels: a DIDS-sensitive (swelling-activated) channel, and a DIDS-insensitive (niflumic acid-sensitive) Cl(-) channel. Anion permeability of the DIDS-insensitive Cl(-) current differed from that of the compound Cl(-) current: Rank order of anion permeability of the DIDS-sensitive Cl(-) channels was I(-) = Br(-) > Cl(-) > gluconate(-), whereas that of the DIDS-insensitive Cl(-) channel was I(-) = Br(-) > Cl(-) > gluconate(-). These results indicate that early mouse embryos have a Cl(-) channel that is highly permeable to amino acids, which may regulate intracellular amino acid concentration.

Abstract  Eight strains of rhizobia isolated from Mediterranean legumes were tested for their ability to use various carbohydrates in the presence of different NaCl concentrations. This study used API 50CH galleries which permitted rapid screening of the effect of salt on the utilization of 49 different carbohydrates. In absence of salt, the strains used a large variety of carbohydrates as energy and carbon sources. Salt tolerant strains nodulating Trigonella foenum-graecum, Cytisus arboreus and Adenocarpus decorticans, grew on a wide range of carbohydrates in hyper-osmotic media containing 500 mu M or 1 M NaCl. Esculin was the preferred carbon source in highly salt stressed media. In milder saline conditions, 175 or 350 PM NaCl, two salt-stress sensitive strains, isolated from Genista erioclada used xylose, ribose, mannose, gluconic acid, galactose, sorbitol, fructose, and the disaccharides, maltose, sucrose, cellobiose and trehalose, but could not grow on mannitol. An unexpected result was that some carbon sources are utilized in presence of salt but not in its absence. The uptake of these carbohydrates is probably activated by salt stress.

Abstract  The two electrophilic Vilsmeier-Haack reagents POCl3.DMF 2 or (CF3SO2)2O.DMF 3 mediate the one-step and selective conversion of O-triethylsilyl (O-TES), O-tert-butyldimethylsilyl (O-TBDMS), O-tert-butyldiphenylsilyl (O-TBDPS), and O-triisopropylsilyl (O-TIPS) ethers of D-glucal to the corresponding C(6)-O-formates.

Abstract  Some N-substituted-3-azabicyclo[3.3.0]octen-7-one derivatives have been synthesized in an enantiomerically pure form starting from tri-O-acetyl-D-glucal via intramolecular Pauson-Khand (IPK) cycloaddition.

Abstract  In this letter, we report synthesis of branched polysaccharide 2 by glycosylation of glucal-type monomer 1 with two free hydroxy groups at position 3 and 4. Monomer 1 polymerized with N-halosuccinimide promoter in acetonitrile solvent at room temperature--50 degrees C. The product was isolated as a petroleum ether insoluble fraction. The structure was determined by 1H and 13C NMR spectra as well as elemental analysis to be a polysaccharide consisting of 2-halo-2-deoxy-alpha-D-mannoside units, indicating that the polymerization proceeded via stereoregular glycosylation manner. The molecular weights determined by GPC with DMF were 3,300-4,000. The degree of branching was estimated by the NMR data of the product from the reaction of 2 with 3,5-dinitrobenzoyl chloride.

Abstract  A method of capillary ion electrophoresis with indirect detection is developed for the simultaneous determination of the sulfur-containing anions S2O4(2-), S2O3(2-), SO4(2-), SO3(2-), and S2- and other anions (Cl-, Br-, NO2-, NO3-, (COO)2(2-), F-, and PO4(3-)) in the corrosion process. The effects of pH, tetradecyltrimethylammonium hydroxide, chromate, 2-[n-cyclohexylamino]-ethane sulfonate, calcium gluconate, and acetonitrile on the migration and resolution of the anions and the stability of sulfur-containing anions are systematically investigated. The detection limits, repeatability, and linearity for the anions are comparatively studied at 374, 274, and 254 nm, and the results show that 374 nm is the optimal length. The simultaneous multiwavelength detection at 374, 254, 214, and 195 nm can assist in confirming the identification of UV-absorbing anions.