A novel metal binding mode of a pyrimidine nucleotide. Crystal structure of [Cu(5′-UMP)(im)2(H2O)]·4H2O

X-ray analysis of the ternary complex [Cu(5′-UMP)(im)2(H2O)]·4H2O, where 5′-UMP uridine-5′-monophosphate and IM = imidazole, reveals a novel metal binding mode of pyrimidine nucleotide through the ribose group.

A Novel Method for the Uniform Incorporation of Grain-Boundary Layer Modifiers in Positive Temperature Coefficient of Resistivity Barium Titanate

The presently developed two-stage process involves diping the prefired porous disks of n-BaTiO3 in nonaqueous solutions containing Al-buty rate, Ti-isopropoxide, and tetraethyl silicate and subsequent sintering. This leads to uniform distribution of the grain-boundary layer (GBL) modifiers (Al2O3+ TiO2+ SiO2) and better control of the grain size as well as the positive temperature coefficient of resistivity characteristics. The technique is particularly suited for GBL modifiers in low concentrations (< 1%).

A novel laser direct write technique for fabrication of thin film MICs

A technique for fabrication of thin-film circuits for microwave integrated circuit (MIC) application is presented. This low-cost fabrication technique utilizes laser direct write of copper patterns on alumina substrates. The method obviates the need for photomasks and photolithography. The film deposition mechanism, deposit film analysis, and MIC fabrication sequence are presented. Performance evaluation of MICs fabricated using this technique is also included

A novel phenomenon of burst of oxygen uptake during decavanadate-dependent oxidation of NADH

Oxidation of NADH by decavanadate, a polymeric form vanadate with a cage-like structure, in presence of rat liver microsomes followed a biphasic pattern. An initial slow phase involved a small rate of oxygen uptake and reduction of 3 of the 10 vanadium atoms. This was followed by a second rapid phase in which the rates of NADH oxidation and oxygen uptake increased several-fold with a stoichiometry of NADH: O2 of 1ratio1. The burst of NADH oxidation and oxygen uptake which occurs in phosphate, but not in Tris buffer, was prevented by SOD, catalase, histidine, EDTA, MnCl2 and CuSO4, but not by the hydroxyl radical quenchers, ethanol, methanol, formate and mannitol. The burst reaction is of a novel type that requires the polymeric structure of decavanadate for reduction of vanadium which, in presence of traces of H2O2, provides a reactive intermediate that promotes transfer of electrons from NADH to oxygen.

Characterization and evaluation of melibiose as novel excipient in tablet compaction

Lactose is probably the most used tablet excipient in the field of pharmacy. Although lactose is thoroughly characterized and available in many different forms there is a need to find a replacer for lactose as a filler/binder in tablet formulations because it has some downsides. Melibiose is a relatively unknown disaccharide that has not been thoroughly characterized and not previously used as an excipient in tablets. Structurally melibiose is close to lactose as it is also formed from the same two monosaccharides, glucose and galactose. Aim of this research is to characterize and to study physicochemical properties of melibiose. Also the potential of melibiose to be used as pharmaceutical tablet excipient, even as a substitute for lactose is evaluated. Current knowledge about fundamentals of tableting and methods for determinating of deformation behavior and tabletability are reviewed. In this research Raman spectroscopy, X-ray powder diffraction (XRPD), near-infrared spectroscopy (NIR) and Fourier-transform infrared spectroscopy (FT-IR) were used to study differences between two melibiose batches purchased from two suppliers. In NIR and FT-IR measurements no difference between materials could be observed. XPRD and Raman however found differences between the two melibiose batches. Also the effects of moisture content and heating to material properties were studied and moisture content of materials seems to cause some differences. Thermal analytical methods, differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to study thermal behaviour of melibiose and difference between materials was found. Other melibiose batch contains residual water which evaporates at higher temperatures causing the differences in thermal behaviour. Scanning electron microscopy images were used to evaluate particle size, particle shape and morphology. Bulk, tapped and true densities and flow properties of melibiose was measured. Particle size of the melibiose batches are quite different resulting causing differences in the flowability. Instrumented tableting machine and compression simulator were used to evaluate tableting properties of melbiose compared to α-lactose monohydrate. Heckel analysis and strain-rate sensitivity index were used to determine deformation mechanism of melibiose monohydrate in relation to α–lactose monohydrate during compaction. Melibiose seems to have similar deformation behaviour than α-lactose monohydrate. Melibiose is most likely fragmenting material. Melibiose has better compactibility than α – lactose monohydrate as it produces tablets with higher tensile strength with similar compression pressures. More compression studies are however needed to confirm these results because limitations of this study.

Bile-Acids in Asymmetric-Synthesis.2. Cholic-Acid Derived Novel Chiral Auxiliaries For Asymmetric Diels-Alder Reactions

Cholic acid-based chiral acrylate 5 yields a Diels-Alder adduct with cyclopent

Chiral polyhydroxylated tetrahydrothiophene derivatives: novel synthesis and structural elucidation by X-ray crystallography, NMR spectroscopy and molecular mechanics calculations

The dideoxygenation reaction of 1,3;4,6-di-O-alkylidene-2,5-di-S-methylthiocarbonyl-D-mannitol derivatives under Barton-McCombie reaction conditions gave the hexahydrodipyranothiophenes 4 and 7 instead of the expected 2,5-dideoxy products. Structural and conformational information on these novel derivatives has been obtained by NMR spectroscopy, single-crystal X-ray crystallography and molecular mechanics calculations.

Dielectric friction and solvation dynamics: Novel results on relaxation in dipolar liquids

In this article we present a new, general but simple, microscopic expression for time-dependent solvation energy of an ion. This expression is surprisingly similar to the expression for the time-dependent dielectric friction on a moving ion. We show that both the Chandra-Bagchi and the Fried-Mukamel formulations of solvation dynamics can be easily derived from this expression. This expression leads to an almost perfect agreement of the theory with all the available computer simulation results. Second, we show here for the first time that the mobility of a light solute ion can significantly accelerate its own solvation, specially in the underdamped limit. The latter result is also in excellent agreement with the computer simulations.

Interferometry with a novel composite material

An interesting application of optical phase conjugation is phase conjugate interferometry. We report here a new approach to real-time interferometry which combines the high phase conjugate efficiency of photorefractive crystals and the fast response times offered by dye-doped polymer films by using a composite structure. The ability of this material to generate two independent but overlapping phase conjugate waves. which can interfere to reveal the phase changes in a test object, is discussed and demonstrated with a specific example.