Mixed insoluble acidic salts of tetravalent metals IV. Crystalline mixed zirconium — Titanium phosphates

Mixed crystalline alpha zirconium — titanium phosphates with variable zirconium to titanium ratios have been prepared both by the well known gel reflux method and a modified HF method. Chemical analysis, X-ray, i.r. and thermal analysis were used to characterize the materials. Exchange capacities for these ion-exchangers have been evaluated by pH-titration combined with radioisotope tract technique for Na⁺, K⁺, Rb⁺ and Cs⁺.     

The structural nature of amorphous Se and Te

We present new photoemission measurements on amorphous and trigonal Te. These results and other recent photoemission experiments on amorphous and trigonal Se are interpreted using density of states and charge density calculations. These studies result in new insights into the possible structural nature of the amorphous phase.     

Optimization of slitlike carbon nanopores for storage of hythane fuel at ambient temperatures

Carbons with slitlike pores can serve as effective host materials for storage of hythane fuel, a bridge between the petrol combustion and hydrogen fuel cells. We have used grand canonical Monte Carlo simulation for the modeling of the hydrogen and methane mixture storage at 293 K and pressure of methane and hydrogen mixture up to 2 MPa. We have found that these pores serve as efficient vessels for the storage of hythane fuel near ambient temperatures and low pressures. We find that, for carbons having optimized slitlike pores of size H congruent with 7 A (pore width that can accommodate one adsorbed methane layer), and bulk hydrogen mole fraction >or=0.9, the volumetric stored energy exceeds the 2010 target of 5.4 MJ dm(-3) established by the U.S. FreedomCAR Partnership. At the same condition, the content of hydrogen in slitlike carbon pores is approximately = 7% by energy. Thus, we have obtained the composition corresponding to hythane fuel in carbon nanospaces with greatly enhanced volumetric energy in comparison to the traditional compression method. We proposed the simple system with added extra container filled with pure free/adsorbed methane for adjusting the composition of the desorbed mixture as needed during delivery. Our simulation results indicate that light slit pore carbon nanomaterials with optimized parameters are suitable filling vessels for storage of hythane fuel. The proposed simple system consisting of main vessel with physisorbed hythane fuel, and an extra container filled with pure free/adsorbed methane will be particularly suitable for combustion of hythane fuel in buses and passenger cars near ambient temperatures and low pressures.     

Estimation of N Absorption and Secretion by Digesta Exchange between 15N Labelled and Unlabelled Pigs

Abstract

Three female pigs (LW～30 kg) were fitted with re-entrant cannulas in the duodenum and the ileum and with bladder catheters. Animal No. 1 was labelled by continuous infusion of [¹⁵N]leucine via a catheter into the vena jugularis. After reaching a steady state in the level of endogenous N (4–5 d after beginning of the infusion) the digesta of the labelled animal No. 1 and the two unlabelled animals were exchanged in a 3 day experiment. During this time the course of transit rates of digesta, digesta N and ¹⁵N through duodenum and ileum as well as the proportion of endogenous N: exogenous N were estimated. Using these data it was possible to calculate the secretion and absorption rates of endogenous and exogenous N in the three segments of the digestive tract: mouth-duodenum, duodenum-ileum, ileum-anus and in addition the reabsorption (intestinal recycling) of the endogenous N during its passage through the gut could be computed.     

Jacobson radical non-nil algebras of Gel’fand-Kirillov dimension 2

For an arbitrary countable field, we construct an associative algebra that is graded, generated by finitely many degree-1 elements, is Jacobson radical, is not nil, is prime, is not PI, and has Gel’fand-Kirillov dimension two. This refutes a conjecture incorrectly attributed to Goodearl.     

Effect of Inoculated Lactic Acid Fermentation on the Fermentable Saccharides and Polyols,Polyphenols and Antioxidant Activity Changes in Wheat Sourdough

Inoculation of sourdough allows the fermentation medium to be dominated by desired microorganisms, which enables determining the kinetics of the conversion of chemical compounds by individual microorganisms. This knowledge may allow the design of functional food products with health features dedicated to consumers with special needs. The aim of the study was to assess the dynamics of transformations of fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) compounds from wheat flour as well as their antioxidant activity during inoculated and spontaneous sourdough fermentation. The FODMAP content in grain products was determined by the fructan content with negligible amounts of sugars and polyols. To produce a low-FODMAP cereal product, the fermentation time is essential. The 72 h fermentation time of L. plantarum-inoculated sourdough reduced the FODMAP content by 91%. The sourdough fermentation time of at least 72 h also positively influenced the content of polyphenols and antioxidant activity, regardless of the type of fermentation. The inoculation of both L. plantarum and L. casei contributed to a similar degree to the reduction in FODMAP in sourdough compared to spontaneous fermentation.     

Intermolecular Interactions in Crystalline Hydroxychloroquine Sulfate in Comparison with Those in Selected Antimalarial Drugs

Abstract The crystal structure of hydroxychloroquine sulfate (OHClQ) was determined in order to compare its conformation and intermolecular interactions to those in the crystalline chloroquine phosphate (ClQP) and quinine salicylate (QSal) monohydrate. The crystals of OHClQ are monoclinic with the space group P2₁/c and unit-cell dimensions: a = 10.4966(1) ?, b = 8.8056(1) ?, c = 21.8603(3) ?, β = 101.074(1)°. The quinoline antimalarial drugs may interact with their putative receptors by formation of characteristic hydrogen-bonded rings. The protonated nitrogen atoms and/or hydroxyl groups of the drug cation are proton donors, while the oxygen atoms of anions are proton acceptors. Water molecules may intermediate in these interactions. Graphical Abstract Hydroxychloroquine sulfate is a drug used in the treatment of malaria and rheumatic diseases. The X-ray structure analysis shows an important role of intermolecular hydrogen bonds in the crystal architecture. Comparison with chloroquine phosphate and quinine salicylate indicates that the organization of the drug cations is determined by the anions.      

Synthesis and theoretical characterization of some new 4‐substituted‐1,3‐diphenyl‐5‐thioxo‐4,5‐dihydro‐1H‐1,2,4‐triazoles with potential pharmacological activity

Synthesis of some new triazoles fused to triazoles 5a–c or thiadiazoles 6a–c and the thiol‐thione tautomeric equilibrium study of the title compounds are reported. The “rule of five” and complementary criteria of pharmacokinetic properties were determined to predict whether these compounds are orally bioavailable. Semiempirical parameterizations have been critically benchmarked for the thiol‐thione tautomeric equilibrium against the DFT calculations. It was shown that unlike the AM1 and PM3 Hamiltonians, which erroneously predict higher stability of the thiol tautomer, the newly developed RM1 Hamiltonian, on the other hand, predicts energetics of this equilibrium in excellent agreement with the DFT results. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:713–718, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20499