α-Chlor-nitrone IV: Zur Stereochemie der λ-Lacton-Synthese und eine Methode zum Aufbau von α-Methyliden-λ-lactonen aus Olefinen. Über synthetische Methoden, 8. (vorläufige) Mitteilung

The Ag⁺-induced reaction between N-cyclohexyl-α-chloro-propionaldonitrone and the two diastereomeric 2-butenes in liquid SO₂ is a stereospecific cis-addition. The use of N-cyclo-hexyl-α,β-dichloro-propionaldonitrone in this type of reaction provides a preparative route from olefines to α-methylidene-butyrolactones.     

Ammonia Borane,NH3BH3: A Threshold Photoelectron–Photoion Coincidence Study of a Potential Hydrogen-Storage Material

We have investigated the photoionization of ammonia borane (AB) and determined adiabatic ionization energy to be 9.26±0.03 eV for the X^{+ 2}E←X ¹A₁ transition. Although the threshold photoelectron spectrum appears at first glance to be similar to the one of the isosteric ethane, the electronic situation differs markedly, due to different orbital energies. In addition, an appearance energy AE_0K(NH₃BH₃, NH₃BH₂⁺)= 10.00±0.03 eV has been determined, corresponding to the loss of a hydrogen atom at the BH₃-site. From the data, a 0 K bond dissociation energy for the B−H bond in the cation of 71.5±3 kJ mol⁻¹ was derived, whereas the one in the neutral compound has been estimated to be 419±10 kJ mol⁻¹.     

Structure,Physicochemical and Biological Properties of an Aqua (2,2′,2′′‐Nitrilotriacetato)‐oxidovanadium(IV) Salt with 4‐Methylpyridinium Cation

The crystal structure of a nitrilotriacetate (nta) oxidovanadium(IV) salt with 4‐methylpyridinium cation, [4‐Me(Py)H]⁺, of [4‐Me(Py)H][VO(nta)(H₂O)] stoichiometry was determined. The complex comprises a discrete mononuclear [VO(nta)(H₂O)]^– coordination entity that can be rarely found among other known compounds containing nitrilotriacetate oxidovanadium(IV) moieties. The complex was characterized by spectroscopic (IR and EPR) methods, magnetic measurements, and thermogravimetry (TG‐FTIR). The stability of the title compound in aqueous solutions was investigated by using the potentiometric titration method. Furthermore, spectrophotometric (UV/Vis) studies have revealed that the compound is capable to scavenge the superoxide free radicals (O₂ ^{? –}) as well as stable organic radicals i.e. 2,2′‐azinobis(3‐ethylbenzothiazoline‐6 sulfonic acid) cation radical (ABTS^{+ ?} ) and 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH ^? ). Finally, biological properties of the complex studied were investigated in relation to its cytoprotective activity against the oxidative damage generated exogenously by using hydrogen peroxide in the HT22 hippocampal neuronal cell line (the MTT assay). Additionally, the biological action of the compound towards two human osteosarcoma HOS and MG‐63 cell lines (the MTT and BrdU tests) as well as the untransformed human osteoblast hFOB 1.19 cell line was tested.     

Dynamic polarizabilities of polyaromatic hydrocarbons using coupled-cluster linear response theory

Coupled-cluster theory with single and double excitations is applied to the calculation of optical properties of large polyaromatic hydrocarbons. Dipole polarizabilities are reported for benzene, pyrene, and the oligoacenes sequence n=2-6. Dynamic polarizabilities were calculated on polyacences as large as pentacene for a single frequency and for benzene and pyrene at many frequencies. The basis set effect was studied for benzene using a variety of basis sets in the Pople [Theor. Chim. Acta 28, 213 (1973)] and Dunning [J. Chem. Phys. 90, 1007 (1989)] families up to aug-cc-pVQZ and the Sadlej pVTZ basis [Collect. Czech. Chem. Commun. 53, 1995 (1998)], which was used exclusively for the largest molecules. Geometries were optimized using HF, B3LYP, PBE0, and MP2 and compared to experiment to measure method dependence and the possible role of bond-length alternation. Finally, the polarizability results were compared to four common density functionals (B3LYP, BLYP, PBE0, PBE).     

Chemical Composition,Nutritional Value,and Acceptance of Nut Bars with the Addition of Edible Insect Powder

Six types of nut-based bars with the addition of edible insect flour were obtained. Flours made from three different insects (Tenebrio molitor L., Acheta domesticus L., Alphitobius diaperinus P.) were used at two different additive levels (15% and 30%) in relation to the weight of the nuts. The addition of insect flour significantly increased protein content and the insoluble fraction of dietary fiber. The largest amount of these compounds was found in bars with 30% cricket flour, 15.51 g/100 g and 6.04 g/100 g, respectively, in comparison to standard bars, 10.78 g/100 g and 3.14 g/100 g, respectively. The greatest consumer acceptance was found in relation to bars with buffalo worm flour. The overall acceptance of these bars was 6.26–6.28 points compared to 6.48 for standard bars. Bars and raw materials were characterized by the high biological value of the protein. Cis linoleic acid dominated among unsaturated fatty acids. The percentage of this compound was in the range of 69.56%, for bars with a 30% addition of buffalo worm flour, to 73.88%, for bars with 15% cricket flour. Instrumental analysis of taste and smell compounds showed the presence of compounds such as 3-methylbutanoic acid, hexanal, and 2,3-pentanedione.     

Antifungal Effect and Inhibition of the Virulence Mechanism of D-Limonene against Candida parapsilosis

Yeasts from the Candida parapsilosis complex are clinically relevant due to their high virulence and pathogenicity potential, such as adherence to epithelial cells and emission of filamentous structures, as well as their low susceptibility to antifungals. D-limonene, a natural compound, emerges as a promising alternative with previously described antibacterial, antiparasitic, and antifungal activity; however, its mechanisms of action and antivirulence activity against C. parapsilosis complex species have not been elucidated. Therefore, in the present study, we aimed to evaluate the antifungal and antivirulence action, as well as the mechanism of action of D-limonene against isolates from this complex. D-limonene exhibited relevant antifungal activity against C. parapsilosis complex yeasts, as well as excellent antivirulence activity by inhibiting yeast morphogenesis and adherence to the human epithelium. Furthermore, the apoptotic mechanism induced by this compound, which is not induced by oxidative stress, represents an important target for the development of new antifungal drugs.     

GHZ Theorems in the Framework of Outcomes in Branching Space-time

A simple algebraic framework is constructed, in which nonstochastic GHZ-Belltheorems can be analyzed. The framework merges Belnap's outcomes in branchingtime with his branching space-time (BST). We show that an important structurein BST, called the family of outcomes of an event, is a Boolean algebra. We provethat there is no common cause that accounts for the results of GHZ-Bell experimentbut we construct common causes for two other setups.     

Excitation energies through the locally renormalized equation-of-motion formalism: singles and doubles model

The stationary conditions obtained from approximate coupled-cluster functional derived from the numerator-denominator connected expansion (NDC) [K. Kowalski and P. Piecuch, J. Chem. Phys. 122, 074107 (2005)] are employed to calculate the linear response of cluster amplitudes. A simple scheme that involves singly and doubly excited amplitudes, termed locally renormalized equation-of-motion approach with singles and doubles (LR-EOMCCSD), is compared with other excited-state methods that include up to two-body operators in the wave function expansion. In particular, the impact of the local denominators on the excitation energies is discussed in detail. Several benchmark calculations on the CH(+), C(2), N(2), O(3), and ClOCl molecules are presented to illustrate the performance of the LR-EOMCCSD approach.     

An Approach to Wavelet Isomorphisms of Function Spaces Via Atomic Representations

Both wavelet and atomic decomposition techniques are essential tools in the study of function spaces nowadays, but they both have their advantages and disadvantages. The celebrated bridge between both concepts was given by the compactly supported Daubechies wavelets which can be interpreted as atoms. In this paper we deal with the converse direction, that is, we present a fairly general approach how to construct compactly supported wavelets when an atomic decomposition is known already. The main idea is Taylor’s expansion combined with our new, so-called \(\varkappa \)-convergence assumption in the admitted sequence spaces. We finally exemplify our main result and collect some known and new settings where such a wavelet decomposition is obtained, e.g., in spaces of Besov or Triebel–Lizorkin type with a doubling weight.