Untersuchung von Fetten und Oelen

Ohne Zusammenfassung     

Rapid genotyping of factor V Leiden mutation using single-tube bidirectional allele-specific amplification and automated ultrathin-layer agarose gel electrophoresis

We report a novel, high-throughput genotyping method by single nucleotide polymorphism (SNP) analysis using bidirectional allele-specific amplification with polymerase chain reaction (PCR) in a single-step/single-tube format. Blood coagulation factor V G1691A (also referred to as Leiden) mutation was chosen as a model system for SNP detection, as this is one of the most common inherited risk factors of thrombosis, effecting 2-5% of the human population. The rationale of our method is the production of allele-specific PCR fragments, different in size, which was achieved by bidirectional amplification, starting from the position of the mutation. Thus, both homozygosity and heterozygosity were readily identified from a single reaction by simply determining the sizes of the resulting PCR products. The advantage of our assay, compared to other single-tube systems, is that this method did not require the use of pre-PCR labeled (fluorophore) primers or probes. Preferential production of the allele-specific products was achieved by a hot-start, time release PCR system. Specificity was increased by introducing a mismatch in the 3'-antepenultimate position of the allele-specific primers. This method made possible the large-scale screening for the factor V Leiden mutation using single-tube PCR followed by automated ultrathin-layer agarose gel electrophoresis, with real-time detection of the "in migratio" ethidium-bromide-labeled fragments.     

Rapid analysis of covalently and non-covalently fluorophore-labeled proteins using ultra-thin-layer sodium dodecylsulfate gel electrophoresis

Gel electrophoresis is one of the most frequently used tools for the separation of complex biopolymer mixtures. In recent years, there has been considerable activity in the separation and characterization of protein molecules by sodium dodecylsulfate (SDS) gel electrophoresis with particular interest in using this technique to separate on the basis of size and to estimate molecular mass and protein purity. Although the method is informative, it is cumbersome, time consuming and lacks automation. In this paper we report an automated, high-performance SDS gel electrophoresis system that is based on electric-field-mediated separation of SDS-protein complexes using an ultra-thin-layer platform. The integrated fiber optic bundle-based scanning laser-induced fluorescence detection technology readily provided high sensitivity, real-time detection of the migrating solute molecules. Rapid separations of covalently and non-covalently labeled proteins were demonstrated in the molecular mass range 14,000 to 205,000 in less than 9 and 16 min, respectively. Excellent quantitation and lane-to-lane migration time reproducibility were found for all the solute components using the multilane separation platform. The limit of detection was found to be 1.5-3 ng/band for both labeling methods, with excellent linearity over a six times serial double-dilution range. Molecular mass calibration plots were compared for both covalently and non-covalently labeled proteins. A linear relationship was found between the molecular mass and electrophoretic mobility in the case of covalently labeled samples, while a non-linear relationship was revealed for the non-covalently labeled samples.     

A general asset-liability management model for the efficient simulation of portfolios of life insurance policies

New regulations and a stronger competition have increased the importance of stochastic asset-liability management (ALM) models for insurance companies in recent years. In this paper, we propose a discrete time ALM model for the simulation of simplified balance sheets of life insurance products. The model incorporates the most important life insurance product characteristics, the surrender of contracts, a reserve-dependent bonus declaration, a dynamic asset allocation and a two-factor stochastic capital market. All terms arising in the model can be calculated recursively which allows an easy implementation and efficient simulation. Furthermore, the model is designed to have a modular organization which permits straightforward modifications and extensions to handle specific requirements. In a sensitivity analysis for sample portfolios and parameters, we investigate the impact of the most important product and management parameters on the risk exposure of the insurance company and show that the model captures the main behaviour patterns of the balance sheet development of life insurance products.     

Die Kristallstruktur des Diacetonalkohol‐Komplexes [Mn(DAA)3]2+[MnI4]2– · DAA

Crystal Structure of the Diacetone Alcohol Complex [Mn(DAA)₃]²⁺[MnI₄]^2– · DAA The title compound has been prepared from MnI₂ and excess diacetone alcohol (4‐hydroxy‐4‐methyl‐2‐pentanon) to give brown single crystals which were suitable for a crystal structure determination. Space group P2₁/c, Z = 4, lattice dimensions at 157 K: a = 1158.3(1), b = 1806.0(1), c = 1846.5(2) pm, β = 97.421(8)°, R₁ = 0.0381. The structure consists of [Mn(DAA)₃]²⁺ ions with distorted octahedral environment of the manganese atom, tetrahedral [MnI₄]^2– ions and a diacetone alcohol molecule which is connected by two hydrogen bridges with the complex cation.     

Diacetonalkohol als Komplexligand. Die Kristallstrukturen von [MnBr2{O=C(Me)CH2–C(Me)2OH}2] und [M{O=C(Me)CH2–C(Me)2OH}2][MCl4] mit M = Fe,Co und Zn

Diacetone Alcohol as Complex Ligand. Crystal Structures of [MnBr₂{O=C(Me)CH₂–C(Me)₂OH}₂] and [M{O=C(Me)CH₂–C(Me)₂OH}₂][MCl₄] with M = Fe, Co, and Zn The metal halides MnBr₂ and MCl₂ (M = Fe, Co, Zn) react with diacetone alcohol (4-hydroxy-4-methyl-2-pentanon) forming the title compounds, which are characterized by IR spectroscopy and crystal structure analyses. [MnBr₂{O=C(Me)CH₂–C(Me₂)OH}₂] ( 1 ): Space group C2/c, Z = 4, lattice dimensions at 293 K: a = 1189.2(4), b = 1317.2(3), c = 1200.0(3) pm, β = 102.25(3)°, R₁ = 0.0256. In 1 the manganese atom is coordinated in a distorted octahedral fashion by the two cis bromine atoms and by the four oxygen atoms of the two diacetone alcohol chelating molecules. The distances Mn–[OH] (223.8 pm) and Mn–[O=C] (222.1 pm) are only slightly different. [M{O=C(Me)CH₂–C(Me)₂OH}₂][MCl₄] [M = Fe ( 2 ), Co ( 3 ), Zn ( 4 )]: 2 and 3 crystallize isotypically with each other in the space group Pc, Z = 4. Lattice dimensions for 2 at 293 K: a = 865.8(3), b = 926.3(2), c = 1401.5(1) pm, β = 104.19(2)°, R₁ = 0.0421. Lattice dimensions for 3 at 293 K: a = 872.3(1), b = 925.7(1), c = 1394.2(3) pm, β = 104.79(2)°, R₁ = 0.0481. As in 1 , the metal atoms of the [M{O=C(Me)CH₂–C(Me)₂OH}₂]²⁺ ions in 2 and 3 are chelated in a distorted octahedral fashion by two diacetone alcohol molecules and associated cis via two μ-Cl atoms of the [MCl₄]^2– anions to form strands. [Zn{O=C(Me)CH₂–C(Me)₂OH}₂][ZnCl₄] ( 4 ): Space group C2/c, Z = 4. Lattice dimensions at 213 K: a = 1582.27(13), b = 1356.15(13), c = 941.93(7) pm, β = 107.283(10)°, R₁ = 0.0328. The zinc atom of the dication in 4 is associated in a distorted octahedral fashion by the two diacetone alcohol chelating molecules in the equatorial positions and trans by two μ-Cl atoms of the [ZnCl₄]^2– ions to form strands.     

Darstellung und strukturuntersuchungen von dimethylmetallacet- und acetimidohydrazinderivaten des galliums und indiums

Trimethylgallium and trimethylindium react with N′,N$\text{-}\text{?}$ dimethylacethydrazine and N′,N″,N′″-trimethylacetimidohydrazine, respectively, to form as a first step, monomeric dimethylmetal derivatives with five-membered ring skeletons. These heterocyclic compounds immediately add a further alkylmetal molecule. The ¹H NMR, IR and Raman spectra of these compounds are discussed and the results of X-ray structure determinations of two of the adducts are given.     

Stereocontrolled Syntheses of Seven‐Membered Carbocycles by Tandem Allene Aziridination/[4+3] Reaction

A tandem allene aziridination/[4+3]/reduction sequence converts simple homoallenic sulfamates into densely functionalized aminated cycloheptenes, where the relative stereochemistry at five contiguous asymmetric centers can be controlled through the choice of the solvent and the reductant. The products resulting from this chemistry can be readily transformed into complex molecular scaffolds which contain up to seven contiguous stereocenters.     

Efficient deterministic numerical simulation of stochastic asset-liability management models in life insurance

New regulations, stronger competitions and more volatile capital markets have increased the demand for stochastic asset-liability management (ALM) models for insurance companies in recent years. The numerical simulation of such models is usually performed by Monte Carlo methods which suffer from a slow and erratic convergence, though. As alternatives to Monte Carlo simulation, we propose and investigate in this article the use of deterministic integration schemes, such as quasi-Monte Carlo and sparse grid quadrature methods. Numerical experiments with different ALM models for portfolios of participating life insurance products demonstrate that these deterministic methods often converge faster, are less erratic and produce more accurate results than Monte Carlo simulation even for small sample sizes and complex models if the methods are combined with adaptivity and dimension reduction techniques. In addition, we show by an analysis of variance (ANOVA) that ALM problems are often of very low effective dimension which provides a theoretical explanation for the success of the deterministic quadrature methods.