Novel Coumarin-Thiadiazole Hybrids and Their Cu(II) and Zn(II) Complexes as Potential Antimicrobial Agents and Acetylcholinesterase Inhibitors

A series of coumarin-thiadiazole hybrids and their corresponding Cu(II) and Zn(II) complexes were synthesized and characterized with the use of spectroscopic techniques. The results obtained indicate that all the coumarin-thiadiazole hybrids act as bidentate chelators of Cu(II) and Zn(II) ions. The complexes isolated differ in their ligand:metal ratio depending on the central metal. In most cases, the Zn(II) complexes are characteristic of a 1:1 ligand:metal ratio, while in the Cu(II) complexes the ligand:metal ratio is 2:1. All compounds were tested as potential antibacterial agents against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacterial strains demonstrating activities notably lower than commercially available antibiotics. The more promising results were obtained from the assessment of antineurodegenerative potency as all compounds showed moderate acetylcholinesterase (AChE) inhibition activity     

Investigation of the Pentathiepin Functionality as an Inhibitor of Feline Immunodeficiency Virus (FIV) via a Potential Zinc Ejection Mechanism,as a Model for HIV Infection

A small diverse library of pentathiepin derivatives were prepared to evaluate their efficacy against the nucleocapsid protein function of the feline immunodeficiency virus (FIV) as a model for HIV, using an in vitro cell culture approach. This study led to the development of nanomolar active compounds with low toxicity.     

Microstructural and Phase Composition Differences Across the Interfaces in Al/Ti/Al Explosively Welded Clads

The microstructure and phase composition of Al/Ti/Al interfaces with respect to their localization were investigated. An aluminum-flyer plate exhibited finer grains located close to the upper interface than those present within the aluminum-base plate. The same tendency, but with a higher number of twins, was observed for titanium. Good quality bonding with a wavy shape and four intermetallic phases, namely, TiAl₃, TiAl, TiAl₂, and Ti₃Al, was only obtained at the interface closer to the explosive material. The other interface was planar with three intermetallic compounds, excluding the metastable TiAl₂ phase. As a result of a 100-hour annealing at 903 K (630 °C), an Al/TiAl₃/Ti/TiAl₃/Al sandwich was manufactured, formed with single crystalline Al layers. A substantial difference between the intermetallic layer thicknesses was measured, with 235.3 and 167.4 µm obtained for the layers corresponding to the upper and lower interfaces, respectively. An examination by transmission electron microscopy of a thin foil taken from the interface area after a 1-hour annealing at 825 K (552 °C) showed a mixture of randomly located TiAl₃ grains within the aluminum. Finally, the hardness results were correlated with the microstructural changes across the samples.

     

Design,Spectroscopy, and Assessment of Cholinesterase Inhibition and Antimicrobial Activities of Novel Coumarin–Thiadiazole Hybrids

A novel series of coumarin–thiadiazole hybrids, derived from substituted coumarin-3-carboxylic acids was isolated and fully characterized with the use of a number of spectroscopic techniques and XRD crystallography. Several of the novel compounds showed intensive fluorescence in the visible region, comparable to that of known coumarin-based fluorescence standards. Moreover, the new compounds were tested as potential antineurodegenerative agents via their ability to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Compared to the commercial standards, only a few compounds demonstrated moderate AChE and BuChE activities. Moreover, the novel derivatives were tested for their antimicrobial activity against a panel of pathogenic bacterial and fungal species. Their lack of activity and toxicity across a broad range of biochemical assays, together with the exceptional emission of some hybrid molecules, highlights the possible use of a number of the novel hybrids as potential fluorescence standards or fluorescence imaging agents.     

The effect of Cs ions on codeposition of SiC particles with nickel

Electrodeposition of SiC particles (technical powder) with nickel matrix in the presence of cesium ions (0–37.6 mM) was investigated. The influence of Cs⁺ concentration on cathodic polarization curves was determined in galvanostatic and potentiodynamic measurements. The presence of Cs⁺ in the solution enhanced in some extent adsorption of Ni²⁺ ions on SiC, but preferential cesium adsorption occurred simultaneously. The last phenomenon resulted in cesium incorporation in the composite coating. The particle content in the deposits (16–24 vol%) was governed by the amount of nickel ions adsorbed on SiC. Structure of the composite coatings was studied by microscopic observations. At highest Cs⁺ concentrations, incorporation of small SiC grains was inhibited. Microhardness of deposits (390–800 HV) was directly dependent on the SiC content in the coatings.     

Reuse of Dairy Product: Evaluation of the Lipid Profile Evolution During and After Their Shelf-Life

The aim of the present work was the characterization of best-by-date dairy products to evaluate their nutritional value for possible re-introduction in the food or feed chain. The attention was devoted to fatty acids and triacylglycerols characterization and their variation during storage of fresh-cheese products before and after their best-by-date. Three kinds of cheese were selected, namely a classic stracchino, stracchino with the addition of yogurt, and one with the addition of probiotic. The variation of FAMEs and TAGs profiles were studied in order to evaluate the degree of variation occurring in the lipid fraction during storage and after the best-by-date. The extraction method was simply scaled-down by ten-fold, starting from the classical Schmid–Bondzynski–Ratzlaff method. The GC run was sped up after a careful comparison of the result with a conventional analysis. The entire data set of results was evaluated performing both a three-way principal component analysis and a traditional two-way one. The three kinds of samples were well discriminated while a change of the lipid profile over the best-by-date period was particularly significant only for the stracchino added with a probiotic.     

Effective operators and spectroscopic properties

In 1968, Wybourne¹ [J. Chem. Phys. 48 (1968) 2596] asked two major questions while pointing out that a few years earlier, “Judd and Ofelt considered only second-order contributions to the oscillator strength:

1. Are the higher-order contributions significant?

2. What new angular-dependent terms enter when the higher-order contributions are considered?”

In the present paper, the answers to these questions are discussed in the form of a report woven onto the background of Wybourne’s publication. The very last sentence of his paper might be taken as an obligation and also as a source of inspiration for all of us who have been trying to describe the properties of rare earth ions over the years. Indeed, he remarks: “At this state (1968) there would seem to be little point in extending calculations to higher orders until actual numerical estimates of the relative importance of the second- and third-order contributions are established.” In this context, the present analysis is performed up to the third-order terms, and the new effective operators are discussed. In addition, to fulfill the demand for “actual numerical estimates”, the results of ab initio calculations are presented to illustrate the hierarchy of important physical mechanisms that contribute to the f↔f transition amplitude.     

Model-driven development for early aspects

Currently, non-functional requirements (NFRs) consume a considerable part of the software development effort. The good news is that most of them appear time and again during system development and, luckily, their solutions can be often described as a pattern independently from any specific application or domain. A proof of this are the current application servers and middleware platforms that can provide configurable prebuilt services for managing some of these crosscutting concerns, or aspects. Nevertheless, these reusable pattern solutions presents two shortcomings, among others: (1) they need to be applied manually; and (2) most of these pattern solutions do not use aspect-orientation, and, since NFRs are often crosscutting concerns, this leads to scattered and tangled representations of these concerns. Our approach aims to overcome these limitations by: (1) using model-driven techniques to reduce the development effort associated to systematically apply reusable solutions for satisfying NFRs; and (2) using aspect-orientation to improve the modularization of these crosscutting concerns. Regarding the first contribution, since the portion of a system related to NFRs is usually significant, the reduction on the development effort associated to these NFRs is also significant. Regarding the second contribution, the use aspect-orientation improves maintenance and evolution of the non-functional requirements that are managed as aspects. An additional contribution of our work is to define a mapping and transition from aspectual requirements to aspect-oriented software architectures, which, in turn, contributes to improve the general issue of systematically relating requirements to architecture. Our approach is illustrated by applying it to a Toll Gate case study.