Eine Isotopenmethode zur Bestimmung der Effektivität von Anlagen zur Agglomerat-Herstellung

Die Mischungseffektivität von Dwight-Lloyd-Anlagen zur Herstellung von Eisen-Agglomerat wurde unter Verwendung von ¹⁴⁰La als Radiotracer untersucht. Das Markierungsverfahren fūr die Ausgangsmaterialien wird beschrieben.     

Calorimetric and spectroscopic studies characterization of newborn rat’ blood serum after maternal administration of cyclophosphamide

Differential scanning microcalorimetry (DSC) and UV–VIS absorption spectroscopy were used to obtain the characteristics of blood serum from newborn rat’ after maternal treatment with cyclophosphamide in comparison with control. The obtained DSC curves reveal a complex endothermic peak due to the unfolding process of various serum proteins. Thermal profiles and absorption spectra of blood serum are sensitive to the age of newborns as well as to effect of maternal administration of cyclophosphamide. The most significant disturbances in serum proteome were observed for 14-day old newborns. The thermodynamic parameters: enthalpy change (∆H), the normalized first moment (M₁) of the thermal transition with respect to the temperature axis and the ratio of C _p^ex at 70 and 60 °C describing denaturation contributions of globulin forms in respect to unliganded albumin with haptoglobin was estimated. Moreover, the second derivative spectroscopy in the UV region was used to resolve the complex protein spectrum. The differences in blood serum detected by DSC and UV–VIS confirm a potential usefulness of these methods for diagnostic and monitoring changes with age as well as the pathological state of blood serum.     

Optical and X-ray Fluorescence Spectroscopy Studies of Bone and Teeth in Newborn Rats After Maternal Treatment with Indinavir

An experiment estimating influence of antiviral drug indinavir treatment during pregnancy on bones and teeth development in newborn rats was performed. Two different fluorescence noninvasive spectroscopy techniques, i.e . laser (407 nm)-induced fluorescence method to characterize the organic fluorescent molecules and X-ray fluorescence analysis to determine mineral components were used to study the surface response of femur, mandible and incisor during their formation in the first month of a rat's life. Differences in autofluorescence depending on the form of the bone were observed on the basis of the emission from enamel in 7-, 14- and 28-day-old newborn rats. The dependence between decrease in intensity of fluorescence and increase in mineralization with age in newborn rats was observed. An enhancement of the autofluorescence and a decrease in the concentration of Ca as a main element, as well as disturbances in the concentration of Zn as trace element were observed for bone as well as teeth in newborns during the first month of their life after maternal administration of indinavir (500 mg kg⁻¹ P.O.) in comparison with the control group. The results indicate that indinavir causes a delay in development of the skeleton and teeth in newborn rats.     

X-Ray Crystal Structure of Betulin–DMSO Solvate

Abstract  

Betulin is a lupane triterpenoid [lup-20(29)-ene-3β,28-diol, C₃₀H₅₀O₂] showing high biological activity. This activity is supposed to be strongly affected by the molecular structure of its polymorphic forms. Different solvate polymorphic forms of betulin have aroused increasing interest as the possible anticancer agents of natural origin. X-ray diffraction was used to investigate crystal structure of (1:1) betulin–DMSO solvate. Title compound crystallizes in the orthorhombic P2₁2₁2₁ space group. Unit cell parameters are as follows: a = 7.0006(2) ?, b = 12.1623(3) ?, c = 33.6991(8) ?, Z = 4. Crystal packing and selected geometric parameters are described. It has been found that the hydrogen bonding and the dipole–dipole interaction between DMSO molecules play the major role in the formation of the crystal structure.     

Novel Re(I) tricarbonyl complexes of chelating ligands with aromatic N-heterocycle ring and aliphatic amine donor - Synthesis, spectroscopic characterization, X-ray structure and DFT calculations

Three novel tricarbonyl rhenium(I) complexes of chelating ligands with aromatic N-heterocycle ring and aliphatic amine donor (2-aminomethylpyridine (ampy), 2-(2-aminophenyl)-1H-benzimidazole (apbi) and 2-(2-aminophenyl)benzothiazole (apbt)) have been synthesized and characterized. The compounds [Re(CO)₃(ampy)Cl] (1), [Re(CO)₃(apbi)Cl] (2) and [Re(CO)₃(apbt)Cl] (3) have been identified by IR, UV-Vis spectroscopy and X-ray analysis. The experimental studies on the complexes 1, 2 and 3 have been accompanied computationally by the density functional theory (DFT) calculations.     

On Silylated Oxonium and Sulfonium Ions and Their Interaction with Weakly Coordinating Borate Anions

Attempts have been made to prepare salts with the labile tris(trimethylsilyl)chalconium ions, [(Me₃Si)₃E]⁺ (E=O, S), by reacting [Me₃Si-H-SiMe₃][B(C₆F₅)₄] and Me₃Si[CB] (CB⁻=carborate=[CHB₁₁H₅Cl₆]⁻, [CHB₁₁Cl₁₁]⁻) with Me₃Si-E-SiMe₃. In the reaction of Me₃Si-O-SiMe₃ with [Me₃Si-H-SiMe₃][B(C₆F₅)₄], a ligand exchange was observed in the [Me₃Si-H-SiMe₃]⁺ cation leading to the surprising formation of the persilylated [(Me₃Si)₂(Me₂(H)Si)O]⁺ oxonium ion in a formal [Me₂(H)Si]⁺ instead of the desired [Me₃Si]⁺ transfer reaction. In contrast, the expected homoleptic persilylated [(Me₃Si)₃S]⁺ ion was formed and isolated as [B(C₆F₅)₄]⁻ and [CB]⁻ salt, when Me₃Si-S-SiMe₃ was treated with either [Me₃Si-H-SiMe₃][B(C₆F₅)₄] or Me₃Si[CB]. However, the addition of Me₃Si[CB] to Me₃Si-O-SiMe₃ unexpectedly led to the release of Me₄Si with simultaneous formation of a cyclic dioxonium dication of the type [Me₃Si-μO-SiMe₂]₂[CB]₂ in an anion-mediated reaction. DFT studies on structure, bonding and thermodynamics of the [(Me₃Si)₃E]⁺ and [(Me₃Si)₂(Me₂(H)Si)E]⁺ ion formation are presented as well as mechanistic investigations on the template-driven transformation of the [(Me₃Si)₃E]⁺ ion into a cyclic dichalconium dication [Me₃Si-μE-SiMe₂]₂²⁺.     

A Taxicab geometry quantification system to evaluate the performance of in silico methods: a case study on adenosine receptors ligands

Journal of Computer-Aided Molecular Design - Among still comparatively few G protein-coupled receptors, the adenosine A2A receptor has been co-crystallized with several ligands, agonists as well as...     

Synthesis of 2-oxo-2,3,5,6-tetrahydro-5-thioxoimidazo[1,2-c]quinazolines by one-pot cyclization of α-aminocarboxylic esters with 2-(isothiocyanato)benzonitrile (ITCB)

The cyclization of 2-(isothiocyanato)benzonitrile with α-aminocarboxylic esters and acids afforded a variety of 2-oxo-2,3,5,6-tetrahydro-5-thioxo-imidazo[1,2-c]quinazolines with very good regioselectivity.     

Studies of 85Sr adsorption on grain fractions of soil

Summary The adsorption of ⁸⁵Sr on grain fractions isolated from four different types of soil was studied. The influence of pH, concentration and presence of calcium ions on the process was investigated. The adsorption process depends mainly on pH, grain size of the solidandthe type of soil. Ca²⁺in the system is lowering the adsorption of ⁸⁵Sr.