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New 2,4-dimethoxyphenyl-based of dithiophosphonic acid derivatives: Synthesis, structural investigations, DFT calculations and assessment of antioxidant and antimicrobial potentials
No full text<p>This study presents a contribution to the existing literature on the synthesis and characterization of new derivatives of perthiophosphonic acid anhydride, namely, 2,4-bis[2,4-dimethoxyphenyl]-1,3-dithia-2,4-diphosphetane 2,4-disulphide. New dithiophosphonic acids, (2,4-methoxyphenyl-(RO)PS2H, R= 2-propyl-, I and R=3methyl-1-butyl-, II), which were synthesized from the reaction of the starting material with 2-propyl alcohol and 3-methyl-1-butyl alcohol, were converted into their corresponding dithiophosphonate salts of the phosphonic acid esters (Ia and IIa). Compounds Ia and IIa react with NiCl2.6H2O to form new nickel(II)dithiophosphonato complexes (Ib and IIb, respectively). The structures of Ia, IIa, Ib and IIb were elucidated by spectroscopic methods. The structures of the complexes with square-plane geometry were also elucidated by single crystal Xray diffraction analysis (SCXRD) and supported by theoretical calculations. Moreover, some DFT studies in the gas phase including the geometrical structures, frontier molecular orbitals, chemical parameters and molecular electrostatic potential (MEP) surfaces were computed for Ib and IIb. The antibacterial activities of Ia and IIa were investigated on gram-positive and gram-negative bacteria, as well as the yeast strain Candida albicans. Of the compounds tested, IIa exhibited a relatively stronger antibacterial activity especially on Listeria monocytogenes, a foodborne pathogen. Weak antimicrobial activities were observed for Ia and IIa on other tested microorganisms, Staphylococcus aureus, Escherichia coli and Candida albicans. Antioxidant studies on Ia and IIa indicated a significantly high free radical scavenging potential.</p>
Valorisation of bread wastes via the bacterial cellulose production
No full text<p>The short shelf life of bread can be attributed to changes in its textural and sensory properties, a process termed staling, and large amounts of bread residue and waste are generated daily. Because the main component of bread is starch, the use of bread wastes as a substrate for bacterial cellulose (BC) production can significantly contribute to valorisation and reuse of wastes. This study aimed to investigate the BC production potential of various stale breads, convert these wastes into usable forms for food and other industries, and increase their economic value. Stale breads were hydrolyzed with dilute acid, and BC-producing bacteria from Kombucha tea were isolated and identified as Gluconobacter oxydans MG2021 (GO). BCs were produced from bread hydrolysates with GO and Komagataeibacter hansenii GA2016 (KH), and their properties were examined. The results indicated that stale breads represented a good source for BC production, as high BC yields were obtained using GO (8.81%-25.02%) and all BCs had superior properties such as high crystallinity (75.96%-91.39%), thermal stability, liquid holding capacity, and fine fibers (40.16-85.39 nm). This study demonstrated that bread wastes could be used as a low-cost substrate for large-scale BC production, and the abundance of bread wastes demonstrated their potential as a resource for commercial BC producers.</p>
Annealing impact on mechanical performance and failure analysis assisted with acoustic inspection of carbon fiber reinforced poly-ether-ketone-ketone composites under flexural and compressive loads
No full text<p>This study investigates the effect of the annealing treatment for carbon fiber reinforced Polyether-ketone-ketone (CF/PEKK) composite structures under flexural and compressive loadings through reference, pre-damaged, and annealed sample sets. Significant recovery of pre-existing damage is observed after the annealing process, following both flexural and compressive loading. Acoustic emission (AE) inspection is employed to monitor the failure behavior and assess the impact of pre-damage and annealing on CF/PEKK composite. Initially, AE inspection reveals that the reference CF/PEKK material exhibits a notable fiber-related failure with 85% of cumulative AE counts under flexural load, whereas matrix-related failures are more pronounced with 92% cumulative AE counts under compressive load. Pre-damages in the matrix alter the cumulative count percentages and initiation time that are related to matrix, interface, and fiber-related failures, under flexural and compressive loadings. After annealing, each cumulative AE count percentages are comparable to reference sample values, due to changes in microstructure and relieving of residual stresses. The annealing effect is further validated through dynamic scanning calorimetry (DSC) analysis results with increased glass transition temperature (Tg) and degree of crystallization (Xc). Overall, these findings indicate that annealing treatment effectively restores structural integrity and improves the mechanical performance of CF/PEKK composites.Highlights Annealing aims for damage recovery in CF/PEKK under flexural and compressive loads. Significant damage recovery in CF/PEKK is seen after annealing. Annealing raises Tg and crystallinity, and enhances CF/PEKK structural integrity.</p>
Microwave-assisted esterification of oleic acid using pyrrolidonium-based bronsted-acidic ionic liquids catalyst
No full text<p>Biodiesel is a liquid fuel obtained by the transesterification reaction of triglycerides and the esterification reaction of free fatty acids. In this study, pyrrolidonium-based Br & Oslash;nsted-acidic ionic liquids (ILs) were applied as catalysts for the production of biodiesel by microwave-assisted esterification of oleic acid with methanol. The effects of reaction temperature, catalyst amount, methanol/oleic acid molar ratio, and reaction time on the oleic acid conversion were investigated. Under optimal conditions, the results demonstrated that N-methyl-2-pyrrolidonium hydrogen sulfate (IL1) and 2-pyrrolidonium hydrogen sulfate (IL2) can achieve conversion rates exceeding 98 %. A comparative analysis with other IL catalysts showed the superior performance of pyrrolidonium-based ILs, especially in terms of Turn Over Frequency (TOF) values. To investigate the effects of different heating methods on the esterification of oleic acid, the esterification reaction was carried out using both conventional and microwave methods. The microwave method is more effective than the conventional method. The reusability of the IL catalyst was investigated, and the recovered catalyst showed excellent stability when it was reused for five consecutive runs without significant loss of activity.</p>
Performance Comparison of Aptamer- and Antibody-Based Biosensors for Bacteria Detection on Glass Surfaces
No full text<p>Antibodies are the most common ligands in commercial and research assay systems for detecting whole pathogen cells. On the other hand, aptamers are superior ligands with many advantages over antibodies in sensitive and robust assay development. Extensive comparisons between aptamer-based biosensors and immunosensors are limited to protein analytes. Here, we report a comparison of ligands (four antibodies and one aptamer for each bacteria) to be used as a biosensor for Escherichia coli and Staphylococcus aureus on glass surfaces through systematic experiments. We have demonstrated that anti-E. coli antibody and mouse monoclonal to S. aureus have the best performance among the compared ligands. Hence, the ligands with the best performance were further investigated within the scope of linear range, analytical sensitivity, and reproducibility of the results. We have demonstrated that anti-E. coli antibody with a capture efficiency of 89.1% and mouse monoclonal to S. aureus with a capture efficiency of 88.2% have the best performance among the compared ligands. The results suggest that antibody ligands function with higher efficiency than aptamer ligands but aptamers have strong potential as an analytical tool.</p>
Dendritic Molecular Baskets for Selective Binding of Toxic Methotrexate
No full text<p>We describe the preparation, assembly, recognition characteristics, and bioactivity of dendritic basket 6(12)-. This novel cavitand has a deep aromatic pocket with three (S)-glutamic acid dendrons at the rim to amplify water solubility and prevent self-association. H-1 NMR spectroscopy, calorimetry (ITC), and mass spectrometry (ESI-MS) measurements validate the formation of an inclusion complex between 6(12)- and anticancer drug methotrexate (MTX2-) in water (K-d = 9.2 mu M). To identify the docking pose, a comparison of computed (DFT and MM) and experimental H-1 NMR chemical shifts suggests that MTX2 folds inside 6(12)- (pi center dot center dot center dot pi), forming HBs with the peptidic dendrons while anchoring (C-H center dot center dot center dot pi) to the aromatic pocket through its N-methyl group. In consequence, 6(12-) selectively binds MTX2- in competition with structurally similar folic acid and leucovorin (reversal poisoning agent). While the host is biocompatible (HEK293; IC50 > 150 mu M) and produces inclusion complex [MTX subset of 6](14)- in cell media, it experiences limitation in pharmacokinetic sequestration of MTX2- as dihydrofolate reductase's affinity to the drug is suggested to prevail over that of 6(12-). Nonetheless, considering the basket's biocompatibility, tunability, and chemoselectivity, it stands as the leading candidate in the pursuit of an effective abiotic antidote for methotrexate poisoning.</p>
Traveling for Security: A Study of Israel's High-Level Diplomatic Visits
No full text<p>This study examines Israel’s foreign policy through an analysis of high-level diplomatic visits conducted by its leaders. Traditionally guided by a security-first approach, Israel’s foreign policy has evolved in the post-Oslo Peace Process era. A growing body of literature suggests a departure from its conventional status-quo stance, toward a foreign policy that increasingly emphasizes economic and diplomatic dimensions. This paper investigates the extent to which high-level visits reflect this shift and explores whether Israel’s post-Oslo foreign policy orientation remains security-driven or has diversified. By analyzing empirical data on high-level visits, the study reveals that, despite new diplomatic initiatives and revisionist undertones, Israel’s foreign policy continues to align predominantly with a status-quo, security-oriented framework.</p>
Global Co-regulatory Cross Talk Between m<SUP>6</SUP>A and m<SUP>5</SUP>C RNA Methylation Systems Coordinate Cellular Responses and Brain Disease Pathways
No full text<p>N6 adenosine and C5 cytosine modification of mRNAs, tRNAs and rRNAs are regulated by the behaviour of distinct sets of writer, reader and eraser effector proteins which are conventionally considered to function independently. Here, we provide evidence of global cross-regulatory and functional interaction between the m6A and m5C RNA methylation systems. We first show that m6A and m5C effector protein transcripts are subject to reciprocal base modification supporting the existence of co-regulatory post-transcriptional feedback loops. Using global mass spectrometry proteomic data generated after biological perturbation to identify proteins which change in abundance with effector proteins, we found novel co-regulatory cellular response relationships between m6A and m5C proteins such as between the m6A eraser, ALKBH5, and the m5C writer, NSUN4. Gene ontology analysis of co-regulated proteins indicated that m6A and m5C RNA cross-system control varies across cellular processes, e.g. proteasome and mitochondrial mechanisms, and post-translational modification processes such as SUMOylation and phosphorylation. We also uncovered novel relationships between effector protein networks including contributing to intellectual disability pathways. Finally, we provided in vitro confirmation of colocalisation between m6A-RNAs and the m5C reader protein, ALYREF, after synaptic NMDA activation. These findings have important implications for understanding control of RNA metabolism, cellular proteomic responses, and brain disease mechanisms.</p>
Subinjective portfolios and rings with a linearly ordered subinjective profile
No full text<p>In this paper we study subinjectivity domains of various R-modules and inclusion relations between these domains. We show that if the class of all subinjectivity domains is linearly ordered, then R is right Noetherian, and is either a right V-ring or a ring with unique noninjective simple module U. For the latter case, if U is projective but not indigent, then there exists a ring decomposition R=SxT such that S is a semisimple Artinian ring and T is an indecomposable right Artinian right hereditary ring. Also, in that case, if the subinjectivity domain of U is the only middle subinjectivity domain, then R is right Artinian.</p>
Unveiling the NLO Potential of New Zn (II) Complex of 6-Methylpyridine-2-Carboxaldehyde: Experimental/DFT Study on Spectral, Static, and Frequency-Dependent Linear/Nonlinear Optical Parameters
No full text<p>Ongoing exploration focuses on synthesizing and characterizing coordination compounds to improve the design of nonlinear optical (NLO)-based materials. In this regard, to examine spectral and static/frequency-dependent linear/NLO parameters, the new Zn (II) complex {[Zn(6-MePyAld)(2)(Cl)]; 6-MePyAld: 6-methylpyridine-2-carboxaldehyde} was synthesized and characterized by using H-1 and C-13 NMR, mass (LC-HRMS), powder XRD, and FTIR spectra. The electronic features of synthesized complex were investigated by considering the TD-CAM-B3LYP/ and TD-M06L/6-311G(d,p)//LanL2DZ levels of time-dependent density functional theory (TD-DFT). Moreover, the theoretical linear optical (LO), second-, and third-order NLO susceptibility tensors/polarization (chi((1))/P-(1), chi((2))/P-(2), chi((3))/P-(3)) parameters for the Zn (II) complex were computed using the DFT/M06L and DFT/CAM-B3LYP levels. The external electric field (E), polarization (P), and electric displacement (D) values of the Zn (II) complex were also calculated using the same DFT levels. To investigate microscopic LO (isotropic polarizability /, and anisotropic polarizability (triangle alpha (0;0)/triangle alpha (-omega;omega)) and second-/third-order NLO (/// and ) parameters for the Zn (II) complex, the DFT/M06L and DFT/CAM-B3LYP levels in the gas phase were used. The triangle alpha (0;0), triangle alpha (-omega;omega), , , and for Zn (II) complex were computed at 17.288 x 10(-24), 21.782 x 10(-24), 14.692 x 10(-30), 466.80 x 10(-30), and 210.79 x 10(-30) esu, respectively, by using the DFT/CAM-B3LYP level. Moreover, the / and in the gas phase computed at the DFT/CAM-B3LYP level for Zn (II) complex were obtained at 129.74 x 10(-36), 3997.6 x 10(-36), and -886.60 x 10(-36) esu, in turn. According to the CAM-B3LYP level, the value is 8.65 and 18.53 times higher than the values of para-nitroaniline (pNA) and urea, respectively. The obtained static/dynamic beta and gamma values of Zn (II) complex are greater than those of urea and pNA. Zn (II) complex exhibited remarkably microscopic second-order and particularly third-order NLO features. It is predicted that our study will shed light on NLO materials that might be used in telecommunication and optoelectronics.</p>