Quotient rings of polynomial rings

Let R be a commutative ring with identity. The multiplicatively closed sets U₂={fR[X]: c(f)–1=R}, (U₂)={fU₂: f is regular} and S={fR[X]: c(f)=R} are studied. By considering various equalities between these sets, many characterizations of Noetherian rings are found. In particular, a Noetherian ring R has depth 1 if and only if S=(U₂): and each maximal ideal of a Noetherian ring is regular if and only if U₂=(U₂).The theory of Prüfer v-multiplication rings (PVMR's) is developed for rings with zero divisors. Six equivalent conditions are given to the statement that an additively regular v-ring R is a PVMR.     

Application of affinity capillary electrophoresis for the determination of binding and thermodynamic constants of enediynes with bovine serum albumin

The binding constants and thermodynamic properties of a series of novel enediyne compounds with bovine serum albumin (BSA) were determined. The enediynes were synthesized, characterized, and then studied by affinity capillary electrophoresis (ACE) methods to derive these recognition parameters. Change in electrophoretic mobility of BSA as a function of enediyne concentration was determined at 25 degrees C providing binding constants of 1.76 x 10(5), 1.14 x 10(5), and 0.68 x 10(5) M(-1) for enediynephenylalanine carboxylic acid, enediynephenylalanine methyl ester, and enediyne carboxylic acid, respectively. The binding constant for the enediynephenylalanine carboxylic acid was in good agreement with that obtained using conventional methodology. Binding constants for the interaction of enediynes with BSA decreased with an increase in temperature. Van't Hoff plots showed a direct correlation between intensity of the binding constant and the sign and magnitude of various thermodynamic parameters (DeltaG, DeltaS, and/or DeltaH).     

Dynamic Renner effect in collisions of C+ with H2

The dynamic Renner effect is shown to permit formation of CH⁺₂ in its first excited (²B₁) state from low energy collisions of C⁺ + H₂. The consequences for C⁺ + H₂. The consequences for C⁺ + H₂ radiative association are discussed.     

Gasanalyse

Ohne Zusammenfassung     

A new restricted access molecularly imprinted polymer capped with albumin for direct extraction of drugs from biological matrices: the case of chlorpromazine in human plasma

A new restricted access molecularly imprinted polymer coated with bovine serum albumin (RAMIP-BSA) was developed, characterized, and used for direct analysis of chlorpromazine in human plasma samples. The RAMIP-BSA was synthesized using chlorpromazine, methacrylic acid, and ethylene glycol dimethacrylate as template, functional monomer, and cross-linker, respectively. Glycerol dimethacrylate and hydroxy methyl methacrylate were used to promote a hydrophilic surface (high density of hydroxyl groups). Afterward, the polymer was coated with BSA using glutaraldehyde as cross-linker, resulting in a protein chemical shield around it. The material was able to eliminate ca. 99 % of protein when a 44-mg mL^?1 BSA aqueous solution was passed through it. The RAMIP-BSA was packed in a column and used for direct analysis of chlorpromazine in human plasma samples in an online column switching high-performance liquid chromatography system. The analytical calibration curve was prepared in a pool of human plasma samples with chlorpromazine concentrations ranging from 30 to 350 μg L^?1. The correlation coefficient obtained was 0.995 and the limit of quantification was 30 μg L^?1. Intra-day and inter-day precision and accuracy presented variation coefficients and relative errors lower than 15 % and within ?15 and 15 %, respectively. The sample throughput was 3 h^?1 (sample preparation and chromatographic analysis steps) and the same RAMIP-BSA column was efficiently used for about 90 cycles.     

Contactless Weighing Up to High Pressures For Analysing Adsorption And Density of Fluids

Adsorption of supercritical fluids methane, nitrogen and argon by active carbons was studied up to a pressure of 500 bar. A three-parameter isothermal equation was used to represent the adsorption equilibrium. This isothermal equation is based on a physical model conception which had already been used for the modelling of adsorption processes with a pressure up to 150 bar. Beside the exact knowledge of the measurable parameters pressure, temperature and fluid composition, the density of the adsorbate are essential for the evaluation of the adsorption analysis. The fluid density can be determined either via equations of state, which is normally the most practicable and fastest way, or via lift measurements of a lowering body in the fluid based on the principle of Archimedes. This work represents and discusses the question of to what extent the fluid density determined under real conditions via equations of state, using, for example, equation of Bender, corresponds to the fluid density measured under high-pressure. This revised version was published online in August 2006 with corrections to the Cover Date.