On groups with every normal subgroup transitive or semiregular

We investigate finite solvable permutation groups in which all normal subgroups are transitive or semiregular. The motivation comes from universal algebra: such groups are examples of collapsing transformation monoids.     

Chain regularity of isotactic polypropylene determined by different thermal fractionation methods

The chain regularity of isotactic polypropylene (iPP) homopolymer and random copolymers was characterized by different thermal fractionation methods in this study. Different stepwise temperature programs were applied in a calorimeter (DSC), in order to develop a method which is significantly faster than stepwise isothermal segregation technique (SIST) and provides reliable information about the chain regularity of iPP. Our studies prove that self-seeding accelerates the crystallization process during annealing in SSA–DSC experiments (successive self-nucleation and annealing). Consequently, the time of isothermal steps can be shortened significantly in the SSA–DSC method. On the other hand, we found that step time should not be too short if the goal of the measurement is the determination of average chain regularity. Our results clearly indicate that both the experimental conditions and the evaluation technique influence the obtained results. A standard experimental procedure is proposed for reliably determining the average chain regularity of iPP. The length of the SSA–DSC temperature program developed in this study is much shorter compared to that of the conventional SIST measurements used recently for such experiments. The proposed SSA–DSC program makes the reliable characterization of a large number of samples on an acceptable timescale possible.     

A straightforward synthesis of indazolo[3,2-a]isoquinolin-6-amines

4-Substituted 1-bromoisoquinolin-3-amines were subjected to Suzuki coupling with o-nitrophenylboronic acid to yield 1-(2-nitrophenyl) isoquinolinamines, which participated in Cadogan cyclization with triethyl phosphite under microwave irradiation in a sealed vial to yield fluorescent indazolo[3,2-a]isoquinolin-6-amines. The new compounds were also functionalized by transformation of the amino group.     

Development of split–splitless PTV large-volume injection for analytes covering a wide boiling point range

A programmed-temperature vaporiser (PTV)–large-volume injection (LVI) method with a two-stage evaporation process was developed capable of effectively introducing analytes covering a wide boiling-point range (from that of n-nonane to that of n-tetracontane). The method uses speed-controlled sample introduction (50 µL) and a simple PTV setup with Peltier Cooling. Besides, an important cause of discrimination of high-boiling compounds in LVI was identified. The method was successfully applied to simplify the sample preparation in the extractable petroleum hydrocarbon analysis of water and soil samples. The method proved to be resistant to matrix contamination. Linearity was tested between 0.01 and 20 µg mL^?1. The correlation coefficients ranged from 0.996 to 0.999. The relative standard deviation calculated from five parallel runs was 2.73%. The major advantage of the method is its simplicity making it an attainable choice for smaller environmental laboratories.     

Using the 186-keV peak for 226Ra activity concentration determination in Hungarian coal-slag samples by gamma-ray spectroscopy

The uranium isotopic abundance and the ²³⁸U–²²⁶Ra secular equilibrium were determined in nine Hungarian coal slag samples. The ²²⁶Ra activity concentration was measured based on the radon decay products and also the ²²⁶Ra peak at 186 keV. Secular equilibrium existed in eight samples, whereas one sample showed a slight disequilibrium. The direct and fast measurement using only the 186 keV peak was validated which can be used after measuring the uranium isotopic ratio and verifying the ²³⁸U–²²⁶Ra secular equilibrium. This method can be used to measure the ²²⁶Ra content of high number of samples from the same geochemical background.     

Glycan Side Reaction May Compromise ETD-Based Glycopeptide Identification

Tris(hydroxymethyl)aminomethane (Tris) is one of the most frequently used buffer ingredients. Among other things, it is recommended and is usually used for lectin-based affinity enrichment of glycopeptides. Here we report that sialic acid, a common ‘capping’ unit in both N- and O-linked glycans may react with this chemical, and this side reaction may compromise glycopeptide identification when ETD spectra are the only MS/MS data used in the database search. We show that the modification may alter N- as well as O-linked glycans, the Tris-derivative is still prone to fragmentation both in ‘beam-type’ CID (HCD) and ETD experiments, at the same time—since the acidic carboxyl group was ‘neutralized’—it will display a different retention time than its unmodified counterpart. We also suggest solutions that—when incorporated into existing search engines—may significantly improve the reliability of glycopeptide assignments.

Thermal stability of rat uterus during development

Summary The age dependence of thermal denaturation was monitored in rats anaesthetized after they're born at 7^th, 14^th, 21^st, 28^th, 35^thand 42^nddays. The samples were stored in rigor or physiological saline solution. The DSC scans in the early age groups show a low temperature exotherm (connective tissues: from gel to liquid crystal transition) and one endotherm (it is very probably the myosin). During further development the endotherms became more and more complex (due to the development of contractile system). At 42 days the scans seem to be similar to the adult ones. In the two buffers the endotherms markedly differ showing that the ATPase activity is present. In adult uterus, treated with nucleotides or estrogen, this activity significantly differs from the skeletal muscle. On the basis of our results we suppose, that the age dependent changes are decisive processes in the development of rat uterus.     

A new cyclization to fused pyrazoles tunable for pericyclic or pseudopericyclic route: an experimental and theoretical study

2-Pyrazinyl (2) and 3-pyridazinylketone arylhydrazones (6) and their benzologues undergo a ring closure reaction to yield pyrazolo[3,4- b]pyrazines (4) and pyrazolo[4,3- c]pyridazines (7), respectively, in acceptable to good yields. The reaction was found to be accelerated by using acidic or basic conditions. Quantum chemical calculations suggest the key step of the mechanism to be a direct cyclization; analysis of aromaticity based on computed magnetic properties revealed its medium-dependent pericyclic or pseudopericyclic character. The cyclization reaction has also been extended for the synthesis of related ring systems ( 9, 12, 14).