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1.
Adv Sci (Weinh) ; : e2401236, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39090836

RESUMEN

Anionic redox allows the direct formation of O─O bonds from lattice oxygens and provides higher catalytic in the oxygen evolution reaction (OER) than does the conventional metal ion mechanism. While previous theories have predicted and experiments have suggested the possible O─O bond, it has not yet been directly observed in the OER process. In this study, operando soft X-ray absorption spectroscopy (sXAS) at the O K-edge and the operando Raman spectra is performed on layered double CoFe hydroxides (LDHs) after intercalation with [Cr(C2O4)3]3-, and revealed a three-step oxidation process, staring from Co2+ to Co3+, further to Co4+ (3d6L), and ultimately leading to the formation of O─O bonds and O2 evolution above a threshold voltage (1.4 V). In contrast, a gradual oxidation of Fe is observed in CoFe LDHs. The OER activity exhibits a significant enhancement, with the overpotential decreasing from 300 to 248 mV at 10 mA cm-2, following the intercalation of [Cr(C2O4)3]3- into CoFe LDHs, underscoring a crucial role of anionic redox in facilitating water splitting.

2.
Chempluschem ; : e202400085, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39161047

RESUMEN

Atomic oxygen radical anion (O•-) represents an important type of reactive centre that exists in both chemical and biological systems. Gas-phase atomic clusters can be studied under isolated and well controlled conditions. Studies of O•--containing clusters in the gas-phase provide a unique strategy to interpret the chemistry of O•- radicals at a strictly molecular level. This review summarizes the research progresses made since 2013 for the reactivity of O•- radicals in the atomically precise metal oxide clusters including negatively charged, nanosized, and neutral heteronuclear clusters benefitting from the development of advanced experimental techniques. New electronic and geometric factors to control the reactivity and product selectivity of O•- radicals under dark and photo-irradiation conditions have been revealed. The detailed mechanisms of O•- generation have been discussed for the reaction systems of nanosized and heteroatom-doped metal oxide clusters. The catalytic reactions mediated by the O•- radicals in metal clusters have also been successfully established and the microscopic mechanisms about the dynamic generation and depletion of O•- radicals have been clearly understood. The studies of O•- containing metal oxide clusters in the gas-phase provided new insights into the chemistry of reactive oxygen species in related condensed-phase systems.

3.
Small ; : e2402767, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39086056

RESUMEN

Electroactive organic electrode materials exhibit remarkable potential in aqueous zinc ion batteries (AZIBs) due to their abundant availability, customizable structures, sustainability, and high reversibility. However, the research on AZIBs has predominantly concentrated on unraveling the storage mechanism of zinc cations, often neglecting the significance of anions in this regard. Herein, bipolar poly(thionine) is synthesized by a simple and efficient polymerization reaction, and the kinetics of different anions are investigated using poly(thionine) as the cathode of AZIBs. Notably, poly(thionine) is a bipolar organic polymer electrode material and exhibits enhanced stability in aqueous solutions compared to thionine monomers. Kinetic analysis reveals that ClO4 - exhibits the fastest kinetics among SO4 2-, Cl-, and OTF-, demonstrating excellent rate performance (109 mAh g-1 @ 0.5 A g-1 and 92 mAh g-1 @ 20 A g-1). Mechanism studies reveal that the poly(thionine) cathode facilitates the co-storage of both anions and cations in Zn(ClO4)2. Furthermore, the lower electrostatic potential of ClO4 - influences the strength of hydrogen bonding with water molecules, thereby enhancing the overall kinetics in aqueous electrolytes. This work provides an effective strategy for synthesizing high-quality organic materials and offers new insights into the kinetic behavior of anions in AZIBs.

4.
Chemistry ; : e202402382, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39087671

RESUMEN

Photo-regulated transmembrane ionophores enable spatial and temporal control over activity, offering promise as targeted therapeutics. Key to such applications is control using bio-compatible visible light. Herein, we report red-shifted azobenzene-derived synthetic anionophores that use amber or red light to trigger (E)-(Z) photoisomerisation and activation of transmembrane chloride transport. We demonstrate that by tuning the thermal half-life of the more active, but thermodynamically unstable, Z isomer to relax on the timescale of minutes, transient activation of ion transport can be achieved by activating with solely with visible light and deactivating by thermal relaxation.

5.
Small ; : e2402492, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39109574

RESUMEN

Enhancing active states on the catalyst surface by modulating the adsorption-desorption properties of reactant species is crucial to optimizing the electrocatalytic activity of transition metal-based nanostructured materials. In this work, an efficient optimization strategy is proposed by co-modulating the dual anions (C and S) in Ni3C/Ni3S2, the heterostructured electrocatalyst, which is prepared via a simple hot-injection method. The presence of Ni3C/Ni3S2 heterojunctions accelerates the charge carrier transfer and promotes the generation of active sites, enabling the heterostructured electrocatalyst to achieve current densities of 10/100 mA cm-2 at 1.37 V/1.53 V. The Faradaic efficiencies for formate production coupled with hydrogen evolution approach 100%, accompanied with a stability record of 350 h. Additionally, operando electrochemical impedance spectroscopy (EIS), in situ Raman spectroscopy, and density functional theory (DFT) calculations further demonstrate that the creation of Ni3C/Ni3S2 heterointerfaces originating from dual anions' (C and S) differentiation is effective in adjusting the d-band center of active Ni atoms, promoting the generation of active sites, as well as optimizing the adsorption and desorption of reaction intermediates. This dual anions co-modulation strategy to stable heterostructure provides a general route for constructing high-performance transition metal-based electrocatalysts.

6.
Acta Crystallogr E Crystallogr Commun ; 80(Pt 8): 886-889, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39108788

RESUMEN

The title compound, bis-[di-thio-bis-(formamidinium)] hexa-bromido-ruthenium dibromide trihydrate, [(NH2)2CSSC(NH2)2]2[RuBr6]Br2·3H2O, crystallizes in the ortho-rhom-bic system, space group Cmcm, Z = 4. The [RuBr6]2- anionic complex has an octa-hedral structure. The Ru-Br distances fall in the range 2.4779 (4)-2.4890 (4) Å. The S-S and C-S distances are 2.0282 (12) and 1.783 (2) Å, respectively. The H2O mol-ecules, Br- ions, and NH2 groups of the cation are linked by hydrogen bonds. The conformation of the cation is consolidated by intra-molecular O-H⋯Br, O-H⋯O, N-H⋯Br and N-H⋯O hydrogen bonds. The [(NH2)2CSSC(NH2)2]2+ cations form a hydrogen-bonded system involving the Br - ions and the water mol-ecules. Two Br - anions form four hydrogen bonds, each with the NH2 groups of two cations, thus linking the cations into a ring. The rings are connected by water mol-ecules, forming N-H⋯O-H⋯Br hydrogen bonds.

7.
Molecules ; 29(15)2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39125112

RESUMEN

The physicochemical properties of natural bentonite and its sorbents were studied. It has been established the modification of natural bentonites using polyhydroxoxides of iron (III) (mod.1_Fe_5-c) and aluminum (III) (mod.1_Al_5-c) by the "co-precipitation" method led to changes in their chemical composition, structure, and sorption properties. It was shown that modified sorbents based on natural bentonite are finely porous (nanostructured) objects with a predominance of pores of 1.5-8.0 nm in size. The modification of bentonite with iron (III) and aluminum compounds by the "co-precipitation" method also leads to an increase in the sorption capacity of the obtained sorbents with respect to bichromate and arsenate anions. A kinetic analysis showed that, at the initial stage, the sorption process was controlled by an external diffusion factor, that is, the diffusion of the sorbent from the solution to the liquid film on the surface of the sorbent. The sorption process then began to proceed in a mixed diffusion mode when it limited both the external diffusion factor and the intra-diffusion factor (diffusion of the sorbent to the active centers through the system of pores and capillaries). To clarify the contribution of the chemical stage to the rate of adsorption of bichromate and arsenate anions by the sorbents under study, kinetic curves were processed using equations of chemical kinetics (pseudo-first-order, pseudo-second-order, and Elovich models). It was found that the adsorption of the studied anions by the modified sorbents based on natural bentonite was best described by a pseudo-second-order kinetic model. The high value of the correlation coefficient for the Elovich model (R2 > 0.9) allows us to conclude that there are structural disorders in the porous system of the studied sorbents, and their surfaces can be considered heterogeneous. Considering that heterogeneous processes occur on the surface of the sorbent, it is natural that all surface properties (structure, chemical composition of the surface layer, etc.) play an important role in anion adsorption.

8.
Se Pu ; 42(8): 799-804, 2024 Aug.
Artículo en Chino | MEDLINE | ID: mdl-39086249

RESUMEN

Urea is a simple organic compound that is widely used in both the industry and daily life. Compared with conventional methods, the preparation of urea by electrochemical synthesis is more environmentally friendly and sustainable. However, after the reaction, low amounts of urea and high concentrations of inorganic ions, including [Formula: see text] concentration was achieved without interference. Thus, the developed method can be applied for the detection of trace urea and other related ions in urea-containing electrolyte products.

9.
Anal Sci ; 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39143455

RESUMEN

The separation and detection of six common inorganic anions (iodate (IO3-), bromate (BrO3-), bromide (Br-), nitrite (NO2-), nitrate (NO3-), and iodide (I-)) in pure water and 35 ‰ artificial seawater were examined by ion chromatography (IC). As packing materials of separation columns, 1-aminoundecyl group chemically bonded silica (AUS) gels were prepared. Separation of the anions in pure water was achieved using separation columns (150 mm × 4.6 mm i.d.) packed with the AUS gels, 0.1 M NaCl + 5 mM phosphate buffer (pH 4.5) as eluent, and a UV detector (wavelength 225 nm). The anions in artificial seawater were separated and detected with a 300 mm-long column without interferences by matrix anions such as chloride (Cl-) and sulfate (SO42-). The stationary phases have high-capacity anion-exchange/hydrophilic/hydrophobic interaction mixed-modes. The IC system was applied to five inorganic anions, IO3-, Br-, NO2-, NO3-, and I- in seawater of the Seto-Inland Sea, Japan. The detection limits (DLs, S/N = 3) were 11 µg L-1 (IO3-), 93 (Br-), 1.3 (NO2-), 1.4 (NO3-), and 1.1 (I-) for a 100-µL sample injection.

10.
ACS Appl Mater Interfaces ; 16(32): 42153-42163, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39091198

RESUMEN

Aqueous zinc-ion batteries (AZIBs) are poised to play a pivotal part in meeting the growing demands for energy storage and powering portable electronics for their superior security, affordability, and environmentally friendly characteristics. However, the detrimental side reactions occurring at the zinc anode and the dendrite caused by uneven zinc plating/stripping have greatly compromised the cycling life of AZIBs, thereby impeding their practical prospects. In this study, the interfacial comodulation strategy was employed by combining the "electrostatic shielding" effect of cations with the characteristic adsorption of anions. Two molar ZnSO4 served as the matrix, and sodium hydroxyethyl sulfonate (SHES) was selected as a low-cost, nontoxic additive. Experimental results confirm that SHES and zinc anode exhibit robust interactions that lead to the formation of an electrostatic shield and a dynamic adsorption layer at the interface, thereby suppressing hydrogen evolution and corrosion. The combined "electrostatic shielding" effect of sodium ions and the robust characteristic adsorption of hydroxyethyl sulfonate anions serve to guide the directed three-dimensional (3D) diffusion of Zn2+, facilitating rapid, stable, and uniform deposition of zinc. Due to these effects, incorporating 0.2 M SHES as an additive extends the cycle life beyond 3600 h and enables a highly reversible process of deposition and stripping in symmetric cells. Additionally, the Zn-Cu half-cell exhibits reliable cycling for over 1400 cycles, achieving an average Coulombic efficiency of 99.6%. Moreover, the introduction of this additive substantially enhances the performance of Zn-MnO2 and Zn-NH4V4O10 full cells. This study demonstrates the practical feasibility of achieving anodes with high reversibility in AZIBs through the implementation of a strategy that involves anion adsorption at the interface, which holds paramount significance for the practical application of AZIBs.

11.
J Int Med Res ; 52(8): 3000605241253447, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39161253

RESUMEN

The aim of this narrative review was to discuss the literature on ß-lactam antibiotic-associated hypokalemia, a potentially life-threatening electrolyte disorder. The PubMed, Web of Science, Cochrane Library, and Scopus databases were searched for articles published between 1965 and 2023, using the following terms: 'hypokalemia' OR 'potassium loss' OR 'potassium deficiency' AND 'beta-lactams' OR 'penicillin' OR 'penicillin G' OR 'cephalosporins' OR 'ceftazidime' OR 'ceftriaxone' OR 'flucloxacillin' OR 'carbapenems' OR 'meropenem' OR 'imipenem' OR 'cefiderocol' OR 'azlocillin' OR 'ticarcillin'. Additional search terms were 'hypokalemia' AND 'epidemiology' AND 'ICU' OR 'intensive care unit' OR 'ER' OR 'emergency department' OR 'ambulatory' OR 'old' OR 'ageing population', and experimental (animal-based) studies were excluded. A total of eight studies were selected and discussed, in addition to nine case reports and case series. Both older and currently used ß-lactam antibiotics (e.g., ticarcillin and flucloxacillin, respectively) have been associated with therapy-related hypokalemia. The incidence of ß-lactam antibiotic-associated hypokalemia may be as high as 40%, thus, the issue of ß-lactam-associated hypokalemia remains clinically relevant. Although other causes of hypokalemia are likely to be diagnosed more frequently (e.g., due to diuretic therapy or diarrhea), the possibility of ß-lactam-induced renal potassium loss should always be considered in individuals with so-called 'unexplained hypokalemia'.


Asunto(s)
Antibacterianos , Hipopotasemia , beta-Lactamas , Hipopotasemia/inducido químicamente , Humanos , beta-Lactamas/efectos adversos , Antibacterianos/efectos adversos , Potasio/sangre
12.
Adv Mater ; : e2408634, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39148167

RESUMEN

Modulating the electronic structure of catalysts to effectively couple the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential for developing high-efficiency anion exchange membrane water electrolyzer (AEMWE). Herein, a coral-like nanoarray composed of nanosheets through the synergistic layering effect of cobalt and the 1D guiding of vanadium is synthesized, which promotes extensive contact between the active sites and electrolyte. The HER and OER activities can be enhanced by modulating the electronic structure through nitridation and phosphorization, respectively, enhancing the strength of metal-H bond to optimize hydrogen adsorption and facilitating the proton transfer to improve the transformation of oxygen-containing intermediates. Resultantly, the AEMWE achieves a current density of 500 mA cm-2 at 1.76 V for 1000 h in 1.0 M KOH at 70 °C. The energy consumption is 4.21 kWh Nm-3 with the producing hydrogen cost of $0.93 per kg H2. Operando synchrotron radiation and Bode phase angle analyses reveal that during the high-energy consumed OER, the dissolution of vanadium species transforms distorted Co-O octahedral into regular octahedral structures, accompanied by a shortening of the Co-Co bond length. This structural evolution facilitates the formation of oxygen intermediates, thus accelerating the reaction kinetics.

13.
Environ Sci Technol ; 2024 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-39135318

RESUMEN

Vacuum-UV (185 nm, VUV) is widely applied to polish reverse osmosis permeate (ROP), such as the production of electronics-grade ultrapure water. In this study, the VUV oxidation of acetaldehyde, a common carbonyl in ROP, was found to be influenced by anions even at low concentrations. Interestingly, the influencing extent and mechanism varied depending on the anions. Bicarbonate minimally affected the VUV-photon absorption and •OH consumption, but at 5000 µg-C·L-1, it decreased the degradation of acetaldehyde by 58.7% possibly by scavenging organic radicals or other radical chain reactions. Nitrate strongly competed for VUV-photon absorption and •OH scavenging through the formation of nitrite, and at 500 µg-N·L-1, it decreased the removal rate of acetaldehyde degradation by 71.2% and the mineralization rate of dissolved organic carbon by 53.4%. Chloride competed for VUV-photon absorption and also generated reactive chlorine species, which did not affect acetaldehyde degradation but influenced the formation of organic byproducts. The radical chain reactions or activation of anions under VUV irradiation could compensate for the decrease in oxidation performance and need further investigation. In real ROPs, the VUV oxidation of acetaldehyde remained efficient, but mineralization was hindered due to nitrate and chloride anions. This study deepens the understanding of the photochemistry and feasibility of VUV in water with low concentrations of anions.

14.
Int J Mol Sci ; 25(14)2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39062977

RESUMEN

The ability of thermoresponsive polymers to respond to temperature with a reversible conformational change makes them promising 'smart' materials for solutions in medical and biotechnological applications. In this work, two such polymers and structural isomers were studied: poly(N-isopropyl acrylamide) (PNiPAm) and poly(2-isopropyl-2-oxazoline) (PiPOx). We compare the critical solution temperatures (CST) of these polymers in D2O and H2O in the presence of Hofmeister series salts, as results obtained under these different solvent conditions are often compared. D2O has a higher dipole moment and electronegativity than H2O, which could significantly alter the CST transition. We used two complementary methods to measure the CST, dynamic light scattering (DLS) and differential scanning calorimetry (DSC) and found that the CST decreased significantly in D2O compared to H2O. In the presence of highly concentrated kosmotropes, the CST of both polymers decreased in both solvents. The influence of the kosmotropic anions was smaller than the water isotope effect at low ionic strengths but considerably higher at physiological ionic strengths. However, the Hofmeister anion effect was quantitatively different in H2O than in D2O, with the largest relative differences observed for Cl-, where the CSTs in D2O decreased more than in H2O measured by DLS but less by DSC. PiPOx was more sensitive than PNiPAm to the presence of chaotropes. It exhibited much higher transition enthalpies and multistep transitions, especially in aqueous solutions. Our results highlight that measurements of thermoresponsive polymer properties in D2O cannot be compared directly or quantitatively to application conditions or even measurements performed in H2O.


Asunto(s)
Polímeros , Solventes , Temperatura , Solventes/química , Polímeros/química , Rastreo Diferencial de Calorimetría , Resinas Acrílicas/química , Óxido de Deuterio/química , Agua/química , Soluciones
15.
J Enzyme Inhib Med Chem ; 39(1): 2372731, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39012078

RESUMEN

This study refers to the intricate world of Acinetobacter baumannii, a resilient pathogenic bacterium notorious for its propensity at antibiotic resistance in nosocomial infections. Expanding upon previous findings that emphasised the bifunctional enzyme PaaY, revealing unexpected γ-carbonic anhydrase (CA) activity, our research focuses on a different class of CA identified within the A. baumannii genome, the ß-CA, designated as 𝛽-AbauCA (also indicated as CanB), which plays a crucial role in the resistance mechanism mediated by AmpC beta-lactamase. Here, we cloned, expressed, and purified the recombinant 𝛽-AbauCA, unveiling its distinctive kinetic properties and inhibition profile with inorganic anions (classical CA inhibitors). The exploration of 𝛽-AbauCA not only enhances our understanding of the CA repertoire of A. baumannii but also establishes a foundation for targeted therapeutic interventions against this resilient pathogen, promising advancements in combating its adaptability and antibiotic resistance.


Asunto(s)
Acinetobacter baumannii , Aniones , Antibacterianos , Inhibidores de Anhidrasa Carbónica , Anhidrasas Carbónicas , Pruebas de Sensibilidad Microbiana , Acinetobacter baumannii/enzimología , Acinetobacter baumannii/efectos de los fármacos , Anhidrasas Carbónicas/metabolismo , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Aniones/farmacología , Aniones/química , Inhibidores de Anhidrasa Carbónica/farmacología , Inhibidores de Anhidrasa Carbónica/química , Inhibidores de Anhidrasa Carbónica/síntesis química , Relación Estructura-Actividad , Relación Dosis-Respuesta a Droga , Estructura Molecular
16.
Molecules ; 29(13)2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38999036

RESUMEN

The aim of this study was a systematic analysis of the influence of anions (chloride and sulfate) on the electrochemical behavior of the Co-Sn system during codeposition from gluconate baths. The pH-dependent multiple equilibria in cobalt-tin baths were calculated using stability constants. The codeposition of the metals was characterized thermodynamically considering the formation of various CoxSny intermetallic phases. The alloys obtained at different potentials were characterized in terms of their elemental (EDS and anodic stripping) and phase compositions (XRD), the development of preferred orientation planes (texture coefficients), surface morphology (SEM), and wettability (water; diiodomethane; surface energy). The mass of the deposits and cathodic current efficiencies were strongly dependent on both the deposition potential and the bath composition. The morphology and composition of the alloys were mainly dependent on the deposition potential, while the effect of the anions was less emphasized. Two-phase alloys were produced at potentials -0.9 V (Ag/AgCl) and lower, and they consisted of a mixture of tetragonal tin and an uncommon tetragonal CoSn phase. The preferential orientation planes of tin grains were dependent on the cobalt incorporation into the deposits and anion type in the bath, while the latter did not affect the preferential orientation plane of the CoSn phase. The surface wettability of the alloys displayed hydrophobicity and oleophilicity originating from the hierarchical porous surface topography rather than the elemental or phase composition. The codeposition of the metals occurs within the progressive nucleation model, but at more electronegative potentials and in the presence of sulfate ions, a transition from progressive to instantaneous nucleation can be possible. This correlated well with the partial polarization curves of the alloy deposition and the texture of the tin phase.

17.
Angew Chem Int Ed Engl ; : e202410210, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39023074

RESUMEN

Zn metal suffers from severe zinc dendrites, anion-related side reactions, hydrogen evolution reaction (HER) and narrow electrochemical stable window (ESW). Herein, an"anions-in-colloid" hydrated deep eutectic electrolyte (ACDE-3) is designed to improve the stability of zinc anode. The ACDE-3 reconfigures the hydrogen-bond (HB) network and regulates the solvation shell. More importantly, the hydroxyl-rich ß-cyclodextrins (ß-CDs) in ACDE-3 self-assemble into micelles, in which the steric effect between the adjacent ß-CDs restricts the movement of anions. This unique "anions-in-colloid" structure enables the eutectic system with a high Zn2+ transference number (tZn2+) of 0.84.  Thus, ACDE-3 inhibits the formation of dendrite, prevents the anion-involved side reactions, suppresses the HER, and enlarges the ESW to 2.32 V. The Zn//Zn symmetric cell delivers a long lifespan of 900 hours at 0.5 mAh cm-2, and the Zn//Cu half cells have a high average columbic efficiency (ACE) of 97.9% at 0.5 mAh cm-2 with a uniform and compact zinc deposition. When matched with a poly(1,5-naphthalenediamine) cathode, the full battery with a low negative/positive capacity ratio of 2 can still cycle steadily for 200 cycles at a current density of 1.0 A g-1. Additionally, this electrolyte can operative over a wide temperature range from -40 °C to 40 °C.

18.
IBRO Neurosci Rep ; 16: 373-394, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39007083

RESUMEN

Superoxide dismutase (SOD) is a common antioxidant enzyme found majorly in living cells. The main physiological role of SOD is detoxification and maintain the redox balance, acts as a first line of defence against Reactive nitrogen species (RNS), Reactive oxygen species (ROS), and other such potentially hazardous molecules. SOD catalyses the conversion of superoxide anion free radicals (O 2 -.) into molecular oxygen (O 2) and hydrogen peroxide (H 2O 2) in the cells. Superoxide dismutases (SODs) are expressed in neurons and glial cells throughout the CNS both intracellularly and extracellularly. Endogenous oxidative stress (OS) linked with enlarged production of reactive oxygen metabolites (ROMs), inflammation, deregulation of redox balance, mitochondrial dysfunction and bioenergetic crisis are found to be prerequisite for neuronal loss in neurological diseases. Clinical and genetic studies indicate a direct correlation between mutations in SOD gene and neurodegenerative diseases, like Amyotrophic Lateral Sclerosis (ALS), Huntington's disease (HD), Parkinson's Disease (PD) and Alzheimer's Disease (AD). Therefore, inhibitors of OS are considered as an optimistic approach to prevent neuronal loss. SOD mimetics like Metalloporphyrin Mn (II)-cyclic polyamines, Nitroxides and Mn (III)- Salen complexes are designed and used as therapeutic extensively in the treatment of neurological disorders. SODs and SOD mimetics are promising future therapeutics in the field of various diseases with OS-mediated pathology.

19.
J Environ Manage ; 366: 121805, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39018859

RESUMEN

Sulfurized nanoscale zero-valent iron supported on biochar (BC-SNZVI) has been successfully synthesized for 2,4,6-trichlorophenol (2,4,6-TCP) removal, while was only effectively under acidic conditions. To obtain highly efficient removal of 2,4,6-TCP within a broader pH range, weak static magnetic fields (WMF) was applied in BC-SNZVI/2,4,6-TCP aqueous systems. Results showed 30 mT WMF supported the most extensive 2,4,6-TCP removal, and 87.4% of 2,4,6-TCP (initial concentration of 30 mg/L) was removed by 0.5 g/L BC-SNZVI at neutral pH (pH = 6.8) within 180 min, which was increased by 54.4% compared to that without WMF. The observed rate constant (Kobs) under 30 mT WMF was 2.1-fold greater than that without WMF. Although three typical anions (NO3- (0.5-10.0 mM), H2PO4- (0.05-0.5 mM), and HCO3- (0.5-5.0 mM)) still inhibited 2,4,6-TCP removal, WMF could efficiently alleviate the inhibitory effects. Moreover, 73.1% of 2,4,6-TCP was successfully removed by BC-SNZVI under WMF in natural water. WMF remarkably boosted the dechlorination of 2,4,6-TCP, increasing the 2,4,6-TCP dechlorination efficiency from 45.2% (in the absence of WMF) to 83.8% (in the presence of WMF) by the end of 300 min. And the complete dechlorination product phenol appeared within 10 min. Force analysis confirmed the magnetic field gradient force (FB) moved paramagnetic Fe2+ at the SNZVI surface along the direction perpendicular to the external applied field, promoting the mass-transfer controlled SNZVI corrosion. Corrosion resistance analysis revealed WMF promoted the electron-transfer controlled SNZVI corrosion by decreasing its self-corrosion potential (Ecorr). With the introduction of sulfur, the magnitude of FB doubled and the Ecorr decreased comparing with NZVI. Our findings provide a facile and viable strategy for treating chlorinated phenols at neutral pH.


Asunto(s)
Carbón Orgánico , Clorofenoles , Hierro , Carbón Orgánico/química , Hierro/química , Clorofenoles/química , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/química , Campos Magnéticos
20.
Angew Chem Int Ed Engl ; : e202409605, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38975961

RESUMEN

Thioamides are widely used structures in pharmaceuticals and agrochemicals, as well as important synthons for the construction of sulfur-containing heterocycles. This report presents a series of visible-light-driven multicomponent reactions of amines, carbon disulfide, and olefins for the mild and versatile synthesis of linear thioamides and cyclic thiolactams. The use of inexpensive and readily available carbon disulfide as the thiocarbonyl source in a radical pathway enables the facile assembly of structurally diverse amine moieties with non-nucleophilic carbon-based reaction partners. Radical thiocarbamoylative cyclization provides a practical protocol that complements traditional approaches to thiolactams relying on deoxythionation. Mechanistic studies reveal that direct photoexcitation of in situ formed dithiocarbamate anions as well as versatile photoinduced electron transfer with diverse electron acceptors are key to the reactions.

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