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Polymers Apr 2024Stretchable ionogels, as soft ion-conducting materials, have generated significant interest. However, the integration of multiple functions into a single ionogel,...
Stretchable ionogels, as soft ion-conducting materials, have generated significant interest. However, the integration of multiple functions into a single ionogel, including temperature tolerance, self-adhesiveness, and stability in diverse environments, remains a challenge. In this study, a new class of fluorine-containing ionogels was synthesized through photo-initiated copolymerization of fluorinated hexafluorobutyl methacrylate and butyl acrylate in a fluorinated ionic liquid 1-butyl-3-methyl imidazolium bis (trifluoromethylsulfonyl) imide. The resulting ionogels demonstrate good stretchability with a fracture strain of ~1300%. Owing to the advantages of the fluorinated network and the ionic liquid, the ionogels show excellent stability in air and vacuum, as well as in various solvent media such as water, sodium chloride solution, and hexane. Additionally, the ionogels display impressive wide temperature tolerance, functioning effectively within a wide temperature range from -60 to 350 °C. Moreover, due to their adhesive properties, the ionogels can be easily attached to various substrates, including plastic, rubber, steel, and glass. Sensors made of these ionogels reliably respond to repetitive tensile-release motion and finger bending in both air and underwater. These findings suggest that the developed ionogels hold great promise for application in wearable devices.
PubMed: 38611271
DOI: 10.3390/polym16071013 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Mar 2024To investigate the effect of asiaticoside on blood pressure and relaxation of thoracic aorta in rats and explore the underlying mechanism.
OBJECTIVE
To investigate the effect of asiaticoside on blood pressure and relaxation of thoracic aorta in rats and explore the underlying mechanism.
METHODS
SD rats treated with 50 and 100 mg/kg asiaticoside by daily gavage for 2 weeks were monitored for systolic blood pressure changes, and histological changes of the thoracic aorta were evaluated using HE staining. In isolated rat endothelium-intact and endothelium-denuded thoracic aorta rings, the effects of asiaticoside on relaxation of the aortic rings were tested at baseline and following norepinephrine (NE)- and KCl-induced constriction. The vascular relaxation effect of asiaticoside was further observed in NE-stimulated endothelium-intact rat aortic rings pretreated with L-nitroarginine methyl ester, indomethacin, zinc protoporphyrin Ⅸ, tetraethyl ammonium chloride, glibenclamide, barium chloride, Iberiotoxin, 4-aminopyridine, or TASK-1-IN-1. The aortic rings were treated with KCl and NE followed by increasing concentrations of CaCl to investigate the effect of asiaticoside on vasoconstriction induced by external calcium influx and internal calcium release.
RESULTS
Asiaticoside at 50 and 100 mg/kg significantly lowered systolic blood pressure in rats without affecting the thoracic aorta histomorphology. While not obviously affecting resting aortic rings with intact endothelium, asiaticoside at 100 mg/kg induced significant relaxation of the rings constricted by KCl and NE, but its effects differed between endothelium-intact and endothelium-denuded rings. In endothelium-intact aortic rings pretreated with indomethacin, ZnPP Ⅸ, barium chloride, glyburide, TASK-1-IN-1 and 4-aminopyridine, asiaticoside did not produce significant effect on NE-induced vasoconstriction, and tetraethylammonium, Iberiotoxin and L-nitroarginine methyl ester all inhibited the relaxation effect of asiaticoside. In KCland NE-treated rings, asiaticoside obviously inhibited CaCl-induced vascular contraction.
CONCLUSION
Asiaticoside induces thoracic aorta relaxation by mediating high-conductance calcium-activated potassium channel opening, promoting nitric oxide release from endothelial cells and regulating Ca influx and outflow, thereby reducing systolic blood pressure in rats.
Topics: Rats; Animals; Aorta, Thoracic; Blood Pressure; Vasodilation; Endothelial Cells; Calcium; Calcium Chloride; Nitroarginine; Rats, Sprague-Dawley; 4-Aminopyridine; Indomethacin; Esters; Endothelium, Vascular; Dose-Response Relationship, Drug; Chlorides; Triterpenes; Barium Compounds
PubMed: 38597444
DOI: 10.12122/j.issn.1673-4254.2024.03.14 -
Protein Science : a Publication of the... May 2024Chemical warfare nerve agents and pesticides, known as organophosphorus compounds inactivate cholinesterases (ChEs) by phosphorylating the serine hydroxyl group located...
Disentangling the formation, mechanism, and evolvement of the covalent methanesulfonyl fluoride acetylcholinesterase adduct: Insights into an aged-like inactive complex susceptible to reactivation by a combination of nucleophiles.
Chemical warfare nerve agents and pesticides, known as organophosphorus compounds inactivate cholinesterases (ChEs) by phosphorylating the serine hydroxyl group located at the active site of ChEs. Over the course of time, phosphorylation is followed by loss of an organophosphate-leaving group and the bond with ChEs becomes irreversible, a process known as aging. Differently, structurally related irreversible catalytic poisons bearing sulfur instead of phosphorus convert ChEs in its aged form only by covalently binding to the key catalytic serine. Kinetic and crystallographic studies of the interaction between Torpedo californica acetylcholinesterase (TcAChE) and a small organosulfonate, methanesulfonyl fluoride (MSF), indeed revealed irreversibly methylsulfonylated serine 200, to be isosteric with the bound aged sarin/soman analogues. The potent bulky reversible inhibitor 7-bis-tacrine (BTA) adopts, in the active site of the crystal structure of the MSF-enzyme adduct, a location and an orientation that closely resemble the one being found in the crystal structure of the BTA-enzyme complex. Remarkably, the presence of BTA accelerates the rate of methanesulfonylation by a factor of two. This unexpected result can be explained on the basis of two facts: i) the steric hindrance exerted by BTA to MSF in accessing the active site and ii) the acceleration of the MSF-enzyme adduct formation as a consequence of the lowering of the rotational and translational degrees of freedom in the proximity of the catalytic serine. It is well known that pralidoxime (2-Pyridine Aldoxime Methyl chloride, 2-PAM) alone or in the presence of the substrate acetylcholine cannot reactivate the active site serine of the TcAChE-MSF adduct. We show that the simultaneous presence of 2-PAM and the additional neutral oxime, 2-[(hydroxyimino)methyl]-l-methylimidazol (2-HAM), triggers the reactivation process of TcAChE within the hour timescale. Overall, our results pave the way toward the likely use of a cocktail of distinctive oximes as a promising recipe for an effective and fast reactivation of aged cholinesterases.
Topics: Cholinesterase Inhibitors; Acetylcholinesterase; Oximes; Serine; Pralidoxime Compounds; Sulfones; Taurine
PubMed: 38591646
DOI: 10.1002/pro.4977 -
IUCrData Mar 2024The structure of the title compound, [RuCl(CHN)(CHOS)], has monoclinic (2/) symmetry. The Ru-N distances of the coordination compound are influenced by the chloride or...
The structure of the title compound, [RuCl(CHN)(CHOS)], has monoclinic (2/) symmetry. The Ru-N distances of the coordination compound are influenced by the chloride or di-methyl-sulfoxide-κ ligands. The mol-ecular structure exhibits disorder for two of the terminal methyl groups of a dimethyl sulfoxide ligand.
PubMed: 38586520
DOI: 10.1107/S2414314624001913 -
Saudi Pharmaceutical Journal : SPJ :... May 2024Despite the fact that synthetic preservatives and antioxidants have strong antibacterial and antioxidant activity, they are frequently associated with negative health...
BACKGROUND
Despite the fact that synthetic preservatives and antioxidants have strong antibacterial and antioxidant activity, they are frequently associated with negative health consequences. Currently, there is an increasing interest in pharmaceutical products that are excellent in quality and free of synthetic preservatives.
METHODS
As a result, the purpose of this research is to assess the antibacterial and antioxidant activities of olive leaf extract, oleuropein, and thymol in various pharmaceutical products. Furthermore, the efficacy of these natural extracts to substitute synthetic preservatives (methyl-propylparaben and benzalkonium chloride) and antioxidants (butylhydroxytoluene) will be investigated.
RESULTS
The results revealed that oleuropein, olive leaf extract, and a blend of oleuropein and thyme oil may be utilized as preservatives at concentrations of (0.6 % w/v), (0.4 % w/v), and (0.4 %/0.1 % v/v), respectively. The results demonstrated that thyme oil and oleuropein have synergistic efficacy against the studied microorganisms. By assessing antibacterial activity, and physical properties, the results demonstrated that pharmaceutical formulations containing natural preservatives were stable and effective for three months under accelerated settings (40 °C/75 % RH).
CONCLUSION
Natural compounds such as oleuropein, olive leaf extract, and thyme oil have shown antibacterial effectiveness equivalent to synthetic preservatives in selected pharmaceutical products. Furthermore, there was synergy in antimicrobial activity between thyme oil and oleuropein and this facilitates the use of these compounds at different levels.
PubMed: 38550330
DOI: 10.1016/j.jsps.2024.102014 -
Molecules (Basel, Switzerland) Mar 2024This scientific article presents research on the electrical conductivity of imidazole-derived ionic liquids (1-methylimidazolium chloride, 1-ethyl-3-methylimidazolium...
This scientific article presents research on the electrical conductivity of imidazole-derived ionic liquids (1-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride and 1-methyl-3-octylimidazolium chloride) in the temperature range of 278.15-313.15 K in N,N-Dimethylformamide. The measurement methods employed relied mainly on conductometric measurements, enabling precise monitoring of the conductivity changes as a function of temperature. Experiments were conducted at various temperature values, which provided a comprehensive picture of the conducting properties of the investigated ionic liquids. The focus of the study was the analysis of the conductometric results, which were used to determine the conductivity function as a function of temperature. Based on the obtained data, a detailed analysis of association constants (K) and thermodynamic parameters such as enthalpy (∆H), entropy (∆S), Gibbs free energy (∆G), Eyring activation enthalpy for charge transport (ΔHλ‡) and diffusion processes (D) was carried out. The conductometric method proved to be an extremely effective tool for accurately determining these parameters, significantly contributing to the understanding of the properties of imidazole-derived ionic liquids in the investigated temperature range. As a result, the obtained results not only provide new insights into the electrical conductivity of the studied ionic liquids but also broaden our knowledge of their thermodynamic behavior under different temperature conditions. These studies may have significant implications for the field of ionic liquid chemistry and may be applied in the design of modern materials with desired conducting properties.
PubMed: 38543006
DOI: 10.3390/molecules29061371 -
Scientific Reports Mar 2024Thermal energy storage utilizing the adsorption of moisture from air is a promising energy storage technology due to its high energy density and minimum heat losses....
Thermal energy storage utilizing the adsorption of moisture from air is a promising energy storage technology due to its high energy density and minimum heat losses. Salt hydrates and salt hydrate composites, such as calcium chloride (CaCl) and CaCl-based composites, have shown favourable energy storage properties in this area of research. However, these materials have shown issues with stability due to swelling and deliquescence. In this work, CaCl was stabilized using three methods: impregnation into silica gel, encapsulation in methyl cellulose, and both impregnation and encapsulation stabilization techniques used simultaneously. Therefore, three CaCl-based composites were synthesized. For the first composite, silica gel was impregnated with CaCl. For the second composite, CaCl was encapsulated by methyl cellulose. For the third composite, silica gel was impregnated with CaCl and the CaCl was encapsulated with methyl cellulose. These samples were structurally characterized using scanning electron microscopy as well as Brunauer-Emmett-Teller (BET) to determine surface area, pore size distribution and nitrogen adsorption isotherms at 77 K. Water vapour adsorption isotherms were also determined at 25 °C for different relative humidities by dynamic vapor sorption (DVS). Similarly, LiCl-based composites were also synthesized and examined in this work, but issues of deliquescence, swelling, and agglomeration made the materials impractical to work with. To determine the prepared materials' thermal energy storage performance, 2-6 g of each sample was tested in a lab-scale apparatus. This process uses the exothermic adsorption of moisture from ambient air in an open thermal energy storage system. The CaCl impregnated silica gel that was encapsulated in methyl cellulose showed reasonably high stability and energy storage performance after 3 hydration and dehydration cycles with minimum agglomeration. An energy storage density of 241 kWh/m (0.87 GJ/m) and specific energy of 630 Wh/kg (2268 kJ/kg) was achieved with this material for 90% inlet relative humidity after a regeneration at 90 °C.
PubMed: 38531916
DOI: 10.1038/s41598-023-50672-6 -
International Journal of Systematic and... Mar 2024Eight colonies of live microbes were isolated from an extensively surface-sterilized halite sample which had been retrieved from a depth of 2000 m from a salt mine in...
Eight colonies of live microbes were isolated from an extensively surface-sterilized halite sample which had been retrieved from a depth of 2000 m from a salt mine in the Qianjiang Depression, Hubei Province, PR China. The eight colonies, obtained after 4 weeks of incubation, were named JI20-1-JI20-8 and JI20-1 was selected as the type strain. The strains have been previously described, including a genomic analysis based on the complete genome for strain JI20-1 and draft genomes for the other strains. In that study, the name was suggested, based on the location of the drilling site. Previous phylogenomic analysis showed that strain JI20-1 is most closely related to the Permian isolate from Alpine rock salt. The orthologous average nucleotide identity (orthoANI) and digital DNA-DNA hybridization (dDDH) percentages between the eight strains are 100-99.6 % and 99.8-96.4 %, respectively. The orthoANI and dDDH values of these strains with respect to the type strains of species of the genus are 89.9-78.2 % and 37.3-21.6 %, respectively, supporting their placement in a novel extremely halophilic archaeal species. The phylogenomic tree based on the comparison of sequences of 632 core-orthologous proteins confirmed the novel species status for these haloarchaea. The polar lipid profile includes phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, and sulfated galactosyl mannosyl galactosyl glucosyl diether, a profile compatible with that of . Based on genomic, phenotypic, and chemotaxonomic characterization, we propose strain JI20-1 (=DSM 114402 = HAMBI 3616) as the type strain of a novel species in the genus , with the name sp. nov.
Topics: Halobacterium; Sequence Analysis, DNA; Phylogeny; RNA, Ribosomal, 16S; Base Composition; Bacterial Typing Techniques; DNA, Bacterial; Fatty Acids; Sodium Chloride; China; Phosphatidylglycerols; DNA, Archaeal; Halobacteriaceae
PubMed: 38512754
DOI: 10.1099/ijsem.0.006296 -
RSC Advances Mar 2024Derivatives of the natural product punicine [1-(2',5'-dihydroxyphenyl)pyridinium chloride] were developed as switchable collectors for the flotation of...
Derivatives of the natural product punicine [1-(2',5'-dihydroxyphenyl)pyridinium chloride] were developed as switchable collectors for the flotation of lithium-containing engineered artifical minerals (EnAMs). These EnAMs are formed by pyrometallurgical processing of end-of-life lithium-ion batteries. Depending on the pH value and the lighting conditions, punicines exist in water as cations, two different electrostatically neutral mesomeric betaines, anionic tripoles, radical cations or radical anions. The radical species form by photochemically induced disproportionation reactions. We prepared punicine derivatives introducing alkyl chains in the pyridinium moiety (4-methyl, 4-ethyl, 4-octyl and 4-undecanyl) to install hydrophobic groups and examined the recovery rates of the flotation of lithium aluminate (LiAlO). We varied the lighting conditions (darkness, daylight, LED irradiation at = 390-400 nm) and the pH value, the collector's and frother's concentration, and the flotation time. With our collectors, recovery rates of lithium aluminate up to 90% were accomplished when the flotation was conducted in Hallimond tubes exposed to daylight at pH 11 in water.
PubMed: 38510489
DOI: 10.1039/d4ra00116h -
Polymers Mar 2024Poly(acrylonitrile-co-methyl acrylate) (PAN-co-MA) electrospun nanofiber (ENF) was used as the support for the formation of polyamide (PA) thin films. The ENF support...
Poly(acrylonitrile-co-methyl acrylate) (PAN-co-MA) electrospun nanofiber (ENF) was used as the support for the formation of polyamide (PA) thin films. The ENF support layer was post-treated with heat-pressed treatment followed by NaOH hydrolysis to modify its support characteristics. The influence of heat-pressed conditions and NaOH hydrolysis on the support morphology and porosity, thin-film formation, surface chemistry, and membrane performances were investigated. This study revealed that applying heat-pressing followed by hydrolysis significantly enhances the physicochemical properties of the support material and aids in forming a uniform polyamide (PA) thin selective layer. Heat-pressing effectively densifies the support surface and reduces pore size, which is crucial for the even formation of the PA-selective layer. Additionally, the hydrolysis of the support increases its hydrophilicity and decreases pore size, leading to higher sodium chloride (NaCl) rejection rates and improved water permeance. When compared with membranes that underwent only heat-pressing, those treated with both heat-pressing and hydrolysis exhibited superior separation performance, with NaCl rejection rates rising from 83% to 98% while maintaining water permeance. Moreover, water permeance was further increased by 29% through n-hexane-rinsing post-interfacial polymerization. Thus, this simple yet effective combination of heat-pressing and hydrolysis presents a promising approach for developing high-performance thin-film nanocomposite (TFNC) membranes.
PubMed: 38475394
DOI: 10.3390/polym16050713