Photoelectron Properties and Organic Molecules Photodegradation Activity of Titania Nanotubes with CuxO Nanoparticles Heat Treated in Air and Argon

Titania is very famous photocatalyst for decomposition of organic pollutants. Its photocatalytic properties significantly depend on the morphology and chemical composition of the samples. Herein, the TiO₂ nanotubes/Cu_xO nanoheterostructures have been synthesized and the effect of heat treatment performed in molecular atmospheres of air and argon on their photoelectrochemical and photocatalytic properties has been studied. The prepared samples have a higher reaction rate constant compared to TiO₂ nanotubes in the decomposition reaction of methylene blue molecules. It is established that in argon treated nanoheterostructures, the copper oxide is present in two phases, CuO and Cu₂O, while in air treated ones there is only CuO. In the TiO₂ nanotubes/Cu_xO samples, Cu²⁺ ions and molecular O₂⁻ radicals were detected while in TiO₂ nanotubes only carbon dangling bond defects are present. The dynamics of O₂⁻ radicals under illumination are discussed. It was shown that the TiO₂ nanotubes do not exhibit photocatalytic activity under visible light. The mechanism of the photocatalytic reaction on the surface of the TiO₂ nanotubes/Cu_xO samples was proposed. It is assumed that a photocatalytic decomposition of organic molecules under visible light at the surface of the nanoheterostructures under investigation is realized mainly by the reaction of these molecules with photogenerated O₂⁻ radicals. The results obtained are completely original and indicate the high promise of the prepared photocatalysts.     

New Type of Nanocomposite CsH2PO4-UiO-66 Electrolyte with High Proton Conductivity

New (1−x)CsH₂PO₄–xUiO-66 electrolytes with high proton conductivity and thermal stability at 230–250 °C were developed. The phase composition and proton conductivity of nanocomposites (x = 0–0.15) were investigated in detail. As shown, the UiO-66 matrix is thermally and chemically suitable for creating composites based on CsH₂PO₄. The CsH₂PO₄ crystal structure remains, but the degree of salt crystallinity changes in nanocomposites. As a result of interface interaction, dispersion, and partial salt amorphization, the proton conductivity of the composite increases by two orders of magnitude in the low-temperature range (up to 200 °C), depending on the UiO-66 fraction, and goes through a maximum. At higher temperatures, up to 250 °C, the conductivity of nanocomposites is close to the superprotonic values of the original salt at low UiO-66 values; then, it decreases linearly within one order of magnitude and drops sharply at x > 0.07. The stability of CsH₂PO₄-UiO-66 composites with high proton conductivity was shown. This creates prospects for their use as proton membranes in electrochemical devices.     

Biological Investigation and Chemical Study of Brassica villosa subsp. drepanensis (Brassicaeae) Leaves

Brassica villosa subsp. drepanensis (Caruel) Raimondo & Mazzola, belonging to the Brassica oleracea complex, is a wild edible plant endemic to western Sicily and a relative of modern cultivated Brassica crops. In this study, the antioxidant properties, anti-inflammatory activities, enzymatic inhibition, and cytotoxicity in cancer cells of B. villosa subsp. drepanensis leaf ethanolic extract were analysed for the first time. In addition, its chemical profile was investigated partitioning the total 70% ethanol extract among ethyl acetate, n-butanol, and water to obtain three residues that were subjected to chromatographic separation. Two flavonol glycosides, a phenol glucoside, two amino acids, and purine/pyrimidine bases were obtained. The presence of the glucosinolate glucoiberin was detected in the water extract by UHPLC-MS analysis. The total polyphenol and flavonoid content of the 70% ethanol extract showed good antioxidant capacities and anti-inflammatory properties by reducing nitric oxide release and reactive oxygen species levels and increasing glutathione in lipopolysaccharide-stimulated RAW 264.7 cells. The extract inhibited the enzymatic activity of α-amylase, α-glucosidase, and, significantly, of lipase. The MTT assay showed that the extract did not affect the viability of normal HFF-1 and RAW 264.7 cells. Among the cancer cell lines tested, an antiproliferative action was only observed in CaCo-2. The cytotoxicity of the extract was further confirmed by LDH release assay and by the destabilization of the oxidative balance. Results confirmed the antioxidant properties of the crude extract responsible for the anti-inflammatory effect on healthy cells and cytotoxicity in cancer cells.     

Essential Oils from Colombian Plants: Antiviral Potential against Dengue Virus Based on Chemical Composition,In Vitro and In Silico Analyses

Currently, there are no therapies to prevent severe dengue disease. Essential oils (EOs) can serve as primary sources for research and the discovery of phytomedicines for alternative therapy. Fourteen EOs samples were obtained by distillation from six plants used in Colombian folk medicine. GC/MS analysis identified 125 terpenes. Cytopathic effect (CPE) reduction assays revealed differences in antiviral activity. EOs of Lippia alba, citral chemotype and carvone-rich fraction; Lippia origanoides, phellandrene chemotype; and Turnera diffusa, exhibited strong antiviral activity (IC₅₀: 29 to 82 µg/mL; SI: 5.5 to 14.3). EOs of Piper aduncum, Ocimum basilicum, and L. origanoides, carvacrol, and thymol chemotypes, exhibited weak antiviral activity (32 to 53% DENV-CPE reduction at 100 µg/mL; SI > 5.0). Cluster and one-way ANOVA analyses suggest that the strong antiviral activity of EOs could be attributed to increased amounts of non-phenolic oxygenated monoterpenes and sesquiterpene hydrocarbons. Docking analyses (AutoDock Vina) predicted binding affinity between the DENV-2 E protein and terpenes: twenty sesquiterpene hydrocarbons (−8.73 to −6.91 kcal/mol), eight oxygenated monoterpenes (−7.52 to −6.98 kcal/mol), and seven monoterpene hydrocarbons (−7.60 to −6.99 kcal/mol). This study reports for the first time differences in the antiviral activity of EOs against DENV, corresponding to their composition of monoterpenes and sesquiterpenes.     

Synthesis,Characterization and DFT Study of a New Family of High-Energy Compounds Based on s-Triazine,Carborane and Tetrazoles

An efficient one-pot synthesis of carborane-containing high-energy compounds was developed via the exploration of carbon–halogen bond functionalization strategies in commercially available 2,4,6-trichloro-1,3,5-triazine. The synthetic pathway first included the substitution of two chlorine atoms in s-triazine with 5-R-tetrazoles (R = H, Me, Et) units to form disubstituted tetrazolyl 1,3,5-triazines followed by the sequential substitution of the remaining chlorine atom in 1,3,5-triazine with carborane N- or S-nucleophiles. All new compounds were characterized by IR- and NMR spectroscopy. The structure of four new compounds was confirmed by single crystal X-ray diffraction analysis. The density functional theory method (DFT B3LYP/6-311 + G*) was used to study the geometrical structures, enthalpies of formation (EOFs), energetic properties and highest occupied and lowest unoccupied molecular orbital (HOMO and LUMO) energies and the detonation properties of synthesized compounds. The DFT calculation revealed compounds processing the maximum value of the detonation velocity or the maximum value of the detonation pressure. Theoretical terahertz frequencies for potential high-energy density materials (HEDMs) were computed, which allow the opportunity for the remote detection of these compounds.     

Polyphenols from Dichrostachys cinerea Fruits Anti-Inflammatory,Analgesic, and Antioxidant Capacity in Freund’s Adjuvant-Induced Arthritic Rat Model

Dichrostachys cinerea (L.) Wigth & Arn. (DC) is widely used in traditional medicine against several inflammatory diseases, especially rheumatoid arthritis, because of its antioxidant and anti-inflammatory effects. This study aimed to characterize the polyphenol-rich DC fruit extracts and investigate the analgesic, anti-inflammatory, and antioxidant effects in a rat inflammation model induced by complete Freund’s adjuvant (CFA). Water and ethanolic extracts were characterized using liquid chromatography coupled with mass spectrometry (LC-MS), Fourier-transform infrared (FTIR) spectroscopy, and gas chromatography coupled with mass spectrometry (GC-MS). The polyphenol-rich extracts were administered in three different concentrations for 30 days. Pain threshold, thermal hyperalgesia, edema, and serum biomarkers specific to inflammatory processes or oxidative stress were evaluated. Both extracts were rich in polyphenolic compounds, mainly flavan-3-ols, proanthocyanidins, and flavone glycosides, which had important in vitro antioxidant capacity. DC fruit extracts administration had the maximum antinociceptive and anti-inflammatory effects after one day since the CFA injection and showed promising results for long-term use as well. The measurement of pro-inflammatory cytokines, cortisol, and oxidative stress parameters showed that DC extracts significantly reduced these parameters, being dose and extract-type dependent. These results showed potential anti-inflammatory, analgesic, and antioxidative properties and revealed the necessity of using a standardized polyphenolic DC extract to avoid result variability.     

Effects of Medicinal Leech-Related Cationic Antimicrobial Peptides on Human Blood Cells and Plasma

Cationic antimicrobial peptides (CAMPs) are considered as next-generation antibiotics with a lower probability of developing bacterial resistance. In view of potential clinical use, studies on CAMP biocompatibility are important. This work aimed to evaluate the behavior of synthetic short CAMPs (designed using bioinformatic analysis of the medicinal leech genome and microbiome) in direct contact with blood cells and plasma. Eight CAMPs were included in the study. Hemolysis and lactate dehydrogenase assays showed that the potency to disrupt erythrocyte, neutrophil and mononuclear cell membranes descended in the order pept_1 > pept_3 ~ pept_5 > pept_2 ~ pept_4. Pept_3 caused both cell lysis and aggregation. Blood plasma and albumin inhibited the CAMP-induced hemolysis. The chemiluminescence method allowed the detection of pept_3-mediated neutrophil activation. In plasma coagulation assays, pept_3 prolonged the activated partial thromboplastin time (APTT) and prothrombin time (at 50 μM by 75% and 320%, respectively). Pept_3 was also capable of causing fibrinogen aggregation. Pept_6 prolonged APTT (at 50 μM by 115%). Pept_2 was found to combine higher bactericidal activity with lower effects on cells and coagulation. Our data emphasize the necessity of investigating CAMP interaction with plasma.     

Almost Diagonalization of $$\tau $$ τ -Pseudodifferential Operators with Symbols in Wiener Amalgam and Modulation Spaces

Journal of Fourier Analysis and Applications - In this paper we focus on the almost-diagonalization properties of $$\tau $$ -pseudodifferential operators using techniques from time-frequency...     

Self-Assembled Binaphthyl-Bridged Amphiphilic AABB Phthalocyanines: Nanostructures for Efficient Antimicrobial Photodynamic Therapy

Herein, the photodynamic activity of phthalocyanine (pc)-assembled nanoparticles against bacterial strains is demonstrated. The photosensitizers (PS) studied in this work are two chiral Zn^IIPcs ( PS-1 and PS-2 ), with an AABB geometry (where A and B refer to differently substituted isoindole constituents). They contain differently functionalized, chiral binaphthyloxy-linked A isoindole units, which determine the hydrophobicity of the system, and cationic methyl pyridinium moieties in the other two isoindoles to embody hydrophilicity. Both compounds have the ability to self-assemble into nanoparticles in aqueous media and have proved efficient in the photo-inactivation of Staphylococcus aureus and Escherichia coli, selected as models of Gram-positive and Gram-negative bacteria. The average size of the nanoparticles was determined by substitution at the binaphthyl core and, in turn, influences the toxicity of the PS. Thus, PS-1 , presenting a nonsubstituted binaphthyl core, forms larger nanoparticles with a larger cationic surface than the octyl-functionalized PS-2 . Although both PSs present similar structure and photophysical features, the self-assembled nanostructures of PS-1 are more effective at killing both types of strain, showing an outstanding photo-inactivation capacity with the Gram-negative E. coli.     

Experimental study of X-ray charge density and the selection of reference points for a source function in η6-(2-methyl-1,4-dihydro-2H-3,1-benzoxazine)tricarbonylchromium(0)

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