Distributive lattices determined by weighted double skeletons

Related to his S-glued sum construction, the skeleton S(L) of a finite lattice L was introduced by C. Herrmann in 1973. Our theorem asserts that if D is a finite distributive lattice and its second skeleton, S(S(D)), is the trivial lattice, then D is characterized by its weighted double skeleton, introduced by the second author in 2006. The assumption on the second skeleton is essential.     

Biparametric multicommutated flow analysis system for determination of human serum phosphoesterase activity

A multicommutated flow analysis (MCFA) system constructed of microsolenoid valves and pumps offering simultaneous determination of activity of acid phosphatase (ACP) and alkaline phosphatase (ALP) in human serum samples has been developed. The MCFA system is based on optoelectronic flow-through detector made of two light emitting diodes and operating according to paired emitter detector diode (PEDD) principle. This photometric PEDD device has been dedicated for detection of p-nitrophenol (NP) generated in the course of enzymatic hydrolysis of p-nitrophenyl phosphate and optimized for the determination of NP in human serum samples. The developed PEDD-based MCFA system allows independent optimization of conditions for reaction and detection steps of photometric ACP and ALP bioassays. Moreover, it allows elimination of photometric interferences from serum matrix components according to two-points kinetic mode of measurement. The single measurement cycle takes 12 min, consists of four measurements (two for each phosphoesterase) and enables determination of serum ACP and ALP activities at physiological and pathological levels. The real analytical utility of the developed MCFA system has been confirmed by analysis of control sera as well as real human serum samples from healthy persons and oncological patients.     

Betaine and Carnitine Derivatives as Herbicidal Ionic Liquids

This study focused on the synthesis and subsequent characterization of herbicidal ionic liquids based on betaine and carnitine, two derivatives of amino acids, which were used as cations. Four commonly used herbicides (2,4‐D, MCPA, MCPP and Dicamba) were used as anions in simple (single anion) and oligomeric (two anions) salts. The obtained salts were subjected to analyzes regarding physicochemical properties (density, viscosity, refractive index, thermal decomposition profiles and solubility) as well as evaluation of their herbicidal activity under greenhouse and field conditions, toxicity towards rats and biodegradability. The obtained results suggest that the synthesized herbicidal ionic liquids displayed low toxicity (classified as category 4 compounds) and showed similar or improved efficacy against weed compared to reference herbicides. The highest increase was observed during field trials for salts containing 2,4‐D as the anion, which also exhibited the highest biodegradability (>75 %).     

Digital model of a vacuum circuit breaker for the analysis of switching waveforms in electrical circuits

The article presents a method of modelling a vaccum circuit breaker in the ATP/EMTPpackage, the results of the verification of the correctness of the developed digitalcircuit breaker model operation and its practical usefulness for analysis of overvoltagesand overcurrents occurring in commutated capacitive electrical circuits and also examplesof digital simulations of overvoltages and overcurrents in selected electricalcircuits.     

S‐Adenosyl Methionine Cofactor Modifications Enhance the Biocatalytic Repertoire of Small Molecule C‐Alkylation

A tandem enzymatic strategy to enhance the scope of C‐alkylation of small molecules via the in situ formation of S‐adenosyl methionine (SAM) cofactor analogues is described. A solvent‐exposed channel present in the SAM‐forming enzyme SalL tolerates 5′‐chloro‐5′‐deoxyadenosine (ClDA) analogues modified at the 2‐position of the adenine nucleobase. Coupling SalL‐catalyzed cofactor production with C‐(m)ethyl transfer to coumarin substrates catalyzed by the methyltransferase (MTase) NovO forms C‐(m)ethylated coumarins in superior yield and greater substrate scope relative to that obtained using cofactors lacking nucleobase modifications. Establishing the molecular determinants that influence C‐alkylation provides the basis to develop a late‐stage enzymatic platform for the preparation of high value small molecules.     

Atomic Hydrogen Induced Chemical Vapor Deposition of Silicon Oxycarbide Thin Films Derived from Diethoxymethylsilane Precursor

Amorphous silicon oxycarbide (a-SiOC:H) films produced by remote plasma RPCVD from diethoxymethylsilane (DEMS) were characterized in terms of their basic properties related to the coatings deposited using conventional plasma enhanced PECVD method. The effect of substrate temperature (T_S) on the growth rate, chemical composition, structure, and properties of resulting a-SiOC:H films is reported. Film growth is an adsorption-controlled process, wherein two mechanisms can be distinguished with a transition at about T_S=70°C. Depending on the temperature, films of different nature can be obtained, from polymer-like to highly crosslinked material with C-Si-O network. The chemical structure of a-SiOC:H films was characterized by FTIR, ¹³C and ²⁹Si solid-state NMR, and X-ray photoelectron spectroscopes. The a-SiOC:H films were also characterized in terms of their density, refractive index, surface morphology, conformality of coverage, hardness, adhesion to a substrate, and friction coefficient. The films were found to be morphologically homogeneous materials exhibiting good conformality of coverage and small surface roughness. Their refractive index exhibits anomalous effect revealing a minimum value at T_S=125°C. Due to their exceptional physical properties a-SiOC:H films produced by RPCVD from DEMS precursor seems to be useful as potential dielectric materials or coatings for various encapsulation applications.