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1.
J Environ Sci (China) ; 148: 57-68, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39095190

RESUMEN

The expandable graphite (EG) modified TiO2 nanocomposites were prepared by the high shear method using the TiO2 nanoparticles (NPs) and EG as precursors, in which the amount of EG doped in TiO2 was 10 wt.%. Followed by the impregnation method, adjusting the pH of the solution to 10, and using the electrostatic adsorption to achieve spatial confinement, the Pt elements were mainly distributed on the exposed TiO2, thus generating the Pt/10EG-TiO2-10 catalyst. The best CO oxidation activity with the excellent resistance to H2O and SO2 was obtained over the Pt/10EG-TiO2-10 catalyst: CO conversion after 36 hr of the reaction was ca. 85% under the harsh condition of 10 vol.% H2O and 100 ppm SO2 at a high gaseous hourly space velocity (GHSV) of 400,000 hr-1. Physicochemical properties of the catalysts were characterized by various techniques. The results showed that the electrostatic adsorption, which riveted the Pt elements mainly on the exposed TiO2 of the support surface, reduced the dispersion of Pt NPs on EG and achieved the effective dispersion of Pt NPs, hence significantly improving CO oxidation activity over the Pt/10EG-TiO2-10 catalyst. The 10 wt.% EG doped in TiO2 caused the TiO2 support to form a more hydrophobic surface, which reduced the adsorption of H2O and SO2 on the catalyst, greatly inhibited deposition of the TiOSO4 and formation of the PtSO4 species as well as suppressed the oxidation of SO2, thus resulting in an improvement in the resistance to H2O and SO2 of the Pt/10EG-TiO2-10 catalyst.


Asunto(s)
Grafito , Oxidación-Reducción , Platino (Metal) , Dióxido de Azufre , Titanio , Titanio/química , Grafito/química , Dióxido de Azufre/química , Platino (Metal)/química , Catálisis , Monóxido de Carbono/química , Agua/química , Contaminantes Atmosféricos/química , Modelos Químicos
2.
J Environ Sci (China) ; 149: 574-584, 2025 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-39181669

RESUMEN

The formation of oligomeric hydrogen peroxide triggered by Criegee intermediate maybe contributes significantly to the formation and growth of secondary organic aerosol (SOA). However, to date, the reactivity of C2 Criegee intermediates (CH3CHOO) in areas contaminated with acidic gas remains poorly understood. Herein, high-level quantum chemical calculations and Born-Oppenheimer molecular dynamics (BOMD) simulations are used to explore the reaction of CH3CHOO and H2SO4 both in the gas phase and at the air-water interface. In the gas phase, the addition reaction of CH3CHOO with H2SO4 to generate CH3HC(OOH)OSO3H (HPES) is near-barrierless, regardless of the presence of water molecules. BOMD simulations show that the reaction at the air-water interface is even faster than that in the gas phase. Further calculations reveal that the HPES has a tendency to aggregate with sulfuric acids, ammonias, and water molecules to form stable clusters, meanwhile the oligomerization reaction of CH3CHOO with HPES in the gas phase is both thermochemically and kinetically favored. Also, it is noted that the interfacial HPES- ion can attract H2SO4, NH3, (COOH)2 and HNO3 for particle formation from the gas phase to the water surface. Thus, the results of this work not only elucidate the high atmospheric reactivity of C2 Criegee intermediates in polluted regions, but also deepen our understanding of the formation process of atmospheric SOA induced by Criegee intermediates.


Asunto(s)
Ácidos Sulfúricos , Ácidos Sulfúricos/química , Aerosoles , Modelos Químicos , Contaminantes Atmosféricos/química , Simulación de Dinámica Molecular , Atmósfera/química
3.
J Environ Sci (China) ; 147: 83-92, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39003086

RESUMEN

The environmental threat posed by stibnite is an important geoenvironmental issue of current concern. To better understand stibnite oxidation pathways, aerobic abiotic batch experiments were conducted in aqueous solution with varying δ18OH2O value at initial neutral pH for different lengths of time (15-300 days). The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were determined. The sulfur isotope fractionation factor (Δ34SSO4-stibnite) values decreased from 0.8‰ to -2.1‰ during the first 90 days, and increased to 2.6‰ at the 180 days, indicating the dominated intermediate sulfur species such as S2O32-, S0, and H2S (g) involved in Sb2S3 oxidation processes. The incorporation of O into sulfate derived from O2 (∼100%) indicated that the dissociated O2 was only directly adsorbed on the stibnite-S sites in the initial stage (0-90 days). The proportion of O incorporation into sulfate from water (27%-52%) increased in the late stage (90-300 days), which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O2 on stibnite-Sb sites. The exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42-. The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.


Asunto(s)
Oxidación-Reducción , Isótopos de Oxígeno , Sulfatos , Isótopos de Azufre , Isótopos de Azufre/análisis , Sulfatos/química , Isótopos de Oxígeno/análisis , Antimonio/química , Modelos Químicos , Aerobiosis , Oxígeno/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Óxidos
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 125013, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39186875

RESUMEN

As a reactive sulfur species, sulfur dioxide (SO2) and its derivatives play crucial role in various physiological processes, which can maintain redox homeostasis at normal levels and lead to the occurrence of many diseases at abnormal levels. So, the development of a suitable fluorescent probe is a crucial step in advancing our understanding of the role of SO2 derivatives in living organisms. Herein, we developed a near-infrared fluorescent probe (SP) based on the ICT mechanism to monitor SO2 derivatives in living organisms in a ratiometric manner. The probe SP exhibited excellent selectivity, good sensitivity, fast response rate (within 50 s), and low detection limit (1.79 µM). In addition, the cell experiment results suggested that the SP has been successfully employed for the real-time monitoring of endogenous and exogenous SO2 derivatives with negligible cytotoxicity. Moreover, SP was effective in detecting SO2 derivatives in mice.


Asunto(s)
Colorantes Fluorescentes , Dióxido de Azufre , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Dióxido de Azufre/análisis , Animales , Ratones , Humanos , Límite de Detección , Espectrometría de Fluorescencia , Imagen Óptica , Células HeLa
5.
Adv Mater ; : e2411302, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39291899

RESUMEN

Although hydrogen production through seawater electrolysis combined with offshore renewable energy can significantly reduce the cost, the corrosive anions in seawater strictly limit the commercialization of direct seawater electrolysis technology. Here, it is discovered that electrolytic anode can be uniformly protected in a seawater environment by constructing NiFeBa-LDH catalyst assisted with additional SO4 2- in the electrolyte. In experiments, the NiFeBa-LDH achieves unprecedented stability over 10 000 h at 400 mA cm-2 in both alkaline saline electrolyte and alkaline seawater. Characterizations and simulations reveal that the atomically dispersed Ba2+ enables the chemical fixation of free SO4 2- on the surface, which generates a dense SO4 2- layer to repel Cl- along with the preferentially adsorbed SO4 2- in the presence of an applied electric field. In terms of the simplicity and effectiveness of catalyst design, it is confident that it can be a beacon for the commercialization of seawater electrolysis technology.

6.
J Mol Model ; 30(10): 339, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39287820

RESUMEN

CONTEXT: Ammonium Tutton salts have been widely studied in recent years due to their thermostructural properties, which make them promising compounds for application in thermochemical energy storage devices. In this work, a detailed experimental study of the Tutton salt with the formula (NH4)2Zn(SO4)2(H2O)6 is carried out. Its structural, vibrational, and thermal properties are analyzed and discussed. Powder X-ray diffraction (PXRD) studies confirm that the compound crystallizes in a structure of a Tutton salt, with monoclinic symmetry and P21/a space group. The Hirshfeld surface analysis results indicate that the main contacts stabilizing the material crystal lattice are H···O/O···H, H···H, and O···O. In addition, a typical behavior of an insulating material is confirmed based on the electronic bandgap calculated from the band structure and experimental absorption coefficient. The Raman and infrared spectra calculated using DFT are in a good agreement with the respective experimental spectroscopic results. Thermal analysis in the range from 300 to 773 K reveals one exothermic and several endothermic events that are investigated using PXRD measurements as a function of temperature. With increasing temperature, two new structural phases are identified, one of which is resolved using the Le Bail method. Our findings suggest that the salt (NH4)2Zn(SO4)2(H2O)6 is a promising thermochemical material suitable for the development of heat storage systems, due to its low dehydration temperature (≈ 330 K), high enthalpy of dehydration (122.43 kJ/mol of H2O), and hydration after 24 h. METHODS: Computational studies using Hirshfeld surfaces and void analysis are conducted to identify and quantify the intermolecular contacts occurring in the crystal structure. Furthermore, geometry optimization calculations are performed based on density functional theory (DFT) using the PBE functional and norm-conserving pseudopotentials implemented in the Cambridge Serial Total Energy Package (CASTEP). The primitive unit cell optimization was conducted using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The electronic properties of band structure and density of states, and vibrational modes of the optimized crystal lattice are calculated and analyzed.

7.
Materials (Basel) ; 17(17)2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39274638

RESUMEN

Corrosion of the molten salts Na2SO4 and NaCl has become one of the major factors in the failure of steel components in boilers and engines. In this study, CoNiCrAlY cobalt-based cladding layers with different NiCr-Cr3C2 ratios were prepared by microbeam plasma cladding technology. The influence of the NiCr-Cr3C2 content on the microstructure, mechanical properties, and molten salt corrosion resistance of CoNiCrAlY was investigated. The CoNiCrAlY with a 25 wt.% NiCr-Cr3C2 (NC25) cladding layer possessed the highest microhardness (348.2 HV0.3) and the smallest coefficient of friction (0.4751), exhibiting great overall mechanical properties. The generation of protective oxides Cr2O3, Al2O3, and spinel phase (Ni,Co)Cr2O4 is promoted by the addition of 25 wt.% NiCr-Cr3C2, which significantly reduces the corrosion of the cladding layer, and this effect is much more obvious at 950 °C than that at 750 °C. Furthermore, its corrosion mechanism was clarified. From the findings emerge a viable solution for the design and development of new high-temperature corrosion-resistant coatings.

8.
Molecules ; 29(17)2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39274951

RESUMEN

Solketal, a widely used glycerol-derived solvent, can be efficiently synthesized through heterogeneous catalysis, thus avoiding the significant product losses typically encountered with aqueous work-up in homogeneous catalysis. This study explores the catalytic synthesis of solketal using solid acid catalysts derived from recovered carbon blacks (rCBs), which are obtained through the pyrolysis of end-of-life tires. This was further converted into solid acid catalysts through the introduction of acidic functional groups using concentrated H2SO4 or 4-benzenediazonium sulfonate (BDS) as sulfonating agents. Additionally, post-pyrolytic rCB treated with glucose and subsequently sulfonated with sulfuric acid was also prepared. Comprehensive characterization of the initial and modified rCBs was performed using techniques such as elemental analysis, powder X-ray diffraction, thermogravimetric analysis, a back titration method, and both scanning and transmission electron microscopy, along with X-ray photoelectron spectroscopy. The catalytic performance of these samples was evaluated through the batch mode glycerol acetalization to produce solketal. The modified rCBs exhibited substantial catalytic activity, achieving high glycerol conversions (approximately 90%) and high solketal selectivity (around 95%) within 30 min at 40 °C. This notable activity was attributed to the presence of -SO3H groups on the surface of the functionalized rCBs. Reusability tests indicated that only rCBs modified with glucose demonstrated acceptable catalytic stability in subsequent acetalization cycles. The findings underscore the potential of utilizing end-of-life tires to produce effective acid catalysts for glycerol valorization processes.

9.
Molecules ; 29(17)2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39274985

RESUMEN

As "chemical chameleons," organosulfones have been widely applied in various desulfonylative functionalization reactions. However, the desulfonylative functionalization of (hetero)arylsulfones through the cleavage of inert C(sp2)-SO2 bonds remains a challenging and underexplored task. Over the past twenty years, the use of (hetero)arylsulfones as arylation reagents has gradually gained attention in diverse cross-coupling reactions under specific catalytic conditions, especially in transition metal-catalysis and photocatalysis chemistry. In this review, we discuss the representative accomplishments and mechanistic insights achieved in desulfonylative reactions of inactive C(sp2)-SO2 bonds in (hetero)arylsulfones, including: (i) transition-metal-catalyzed desulfonylative cross-coupling reactions and (ii) photo-/electrocatalytic radical desulfonylative coupling reactions. We anticipate that this review will provide an overall perspective in this area to a general audience of researchers and stimulate further innovative strategies for desulfonylative functionalization of inert arylsulfones.

10.
Artículo en Inglés | MEDLINE | ID: mdl-39235950

RESUMEN

High-nickel (Ni ≥ 90%) cathodes which have a high specific capacity hold great potential for next-generation lithium-ion batteries (LIBs). However, their practical application is restricted by their high interfacial reactivity because of the presence of residual lithium (Li) compounds on the surface. Herein, the LiNi0.9Co0.06Mn0.04O2 (NCM90) cathode is surface-modified with sulfur (S) via a simple and feasible dry mixing and low-temperature heat treatment, converting the residual lithium compound on the surface into inactive lithium sulfate (Li2SO4). This induces the formation of a stable inorganic enriched electrode-electrolyte interface on the cathode surface and inhibits the occurrence of side reactions, ultimately inhibiting lattice collapse and the dissolution of transition metal ions. After modifying, the capacity retention rates of NCM90/Li and NCM90/graphite cells are both greatly enhanced after long cycling. This work provides a new idea for the rational design of the electrode-electrolyte interface of high-nickel cathodes.

11.
Artículo en Inglés | MEDLINE | ID: mdl-39248727

RESUMEN

The development of cathode materials has always been one of the most crucial areas of research in the field of sodium-ion batteries. Sulfate-based polyanionic materials, known for their high working voltage characteristics, have received widespread attention. In this work, a fluoro-sulfate sodium-ion battery cathode material, Na3Fe2(SO4)3F modified with carbon nanotubes, was developed using a low-temperature solid-state annealing method. This Na3Fe2(SO4)3F cathode exhibits an exceptionally high voltage of 3.77 V, excellent discharge capacity (102 mAh/g at 0.1C), and good rate capability. This material broadens the research directions for cathode materials and holds promise as a foundation for the further development of high-performance sodium-ion batteries.

12.
J Comput Chem ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39240057

RESUMEN

Sulfonyl fluorides hold significant importance as highly valued intermediates in chemical biology due to their optimal balance of biocompatibility with both aqueous stability and protein reactivity. The Cornella group introduced a one-pot strategy for synthesizing aryl sulfonyl fluorides via Bi(III) redox-neutral catalysis, which facilitates the transmetallation and direct insertion of SO2 into the BiC(sp2) bond giving the aryl sulfonyl fluorides. We report herein a comprehensive computational investigation of the redox-neutral Bi(III) catalytic mechanism, disclose the critical role of the Bi(III) catalyst and base (i.e., K3PO4), and uncover the origin of SO2 insertion into the Bi(III)C(sp2) bond. The entire catalysis can be characterized via three stages: (i) transmetallation generating the Bi(III)-phenyl intermediate IM3 facilitated by K3PO4. (ii) SO2 insertion into IM3 leading to the formation of Bi(III)-OSOAr intermediate IM5. (iii) IM5 undergoes S(IV)-oxidation yielding the aryl sulfonyl fluoride product 4 and liberating the Bi(III) catalyst for the next catalytic cycle. Each stage is kinetically and thermodynamically feasible. Moreover, we explored other some small molecules (NO2, CO2, H2O, N2O, etc.) insertion reactions mediated by the Bi(III)-complex, and found that NO2 insertions could be easily achieved due to the low insertion barriers (i.e., 17.5 kcal/mol). Based on the detailed mechanistic study, we further rationally designed additional Bi(III) and Sb(III) catalysts, and found that some of which exhibit promising potential for experimental realization due to their low barriers (<16.4 kcal/mol). In this regard, our study contributes significantly to enhancing current Bi(III)-catalytic systems and paving the way for novel Bi(III)-catalyzed aryl sulfonyl fluoride formation reactions.

13.
Heliyon ; 10(16): e36385, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39247330

RESUMEN

The aim of this study is to classify seven types of Irish milk (butter, fresh, heart active, lactose free, light, protein, and slimline), supplied by a specific company, using vibrational spectroscopy methods: Near infrared (NIR), mid infrared (MIR), and Raman spectroscopy. In this regard, chemometric methods were used, and the impact of spectral data fusion on prediction accuracy was evaluated. A total of 105 samples were tested, with 21 used in the test set. The study assessed principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and sequential and orthogonalized partial least squares linear discriminant analysis (SO-PLS-LDA) for classifying different milk types. The prediction accuracy, when applying PLS-DA on individual blocks of data and low-level fused data, did not exceed 85.71 %. However, implementing the SO-PLS-LDA strategy significantly improved the accuracy to 95 %, suggesting a promising method for the development of classification models for milk using data fusion strategies.

14.
Vive (El Alto) ; 7(20)ago. 2024.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1570121

RESUMEN

La calidad del sueño en los estudiantes es un factor esencial que influye en el correcto desarrollo de los procesos cognitivos del aprendizaje, así como en la calidad de vida y la salud mental y física de los futuros profesionales. Objetivo: Evaluar la relación entre la ansiedad, la depresión y la calidad del sueño en estudiantes de la carrera de Odontología de la Universidad Nacional del Altiplano de Puno. Materiales y métodos: Estudio de tipo observacional de cohorte transversal con la participación de 78 estudiantes, con edad promedio de 22.63±2.87 años, con una distribución de género de 32 varones (41,0 %) y 46 mujeres (59,0 %). Se utilizó la escala de valoración de Hamilton para la evaluación de la ansiedad y la depresión, con una consistencia interna de α = 0,88 y 0,86, respectivamente y el cuestionario de Pittsburgh para medir el índice de calidad del sueño (α = 0,87). Resultados: En el modelo predictivo los coeficientes estandarizados ß señalan que la ansiedad psíquica (ß = -,870; p<0,001), la depresión (ß = ,119; p<0,05) y el desarrollo de prácticas clínicas (ß = -0,019; p<0,05) fueron los factores que más contribuyeron significativamente al índice de calidad del sueño de los estudiantes. Conclusión: Estos hallazgos subrayan la importancia de abordar los problemas del sueño como parte integral del tratamiento de la ansiedad y la depresión, además de resaltar la necesidad de tener en cuenta la salud mental en la evaluación y el manejo de los trastornos del sueño.


The quality of sleep-in students is an essential factor that influences the correct development of cognitive learning processes, as well as the quality of life and the mental and physical health of future professionals. Objective: To evaluate the relationship between anxiety, depression and sleep quality in students of the Dentistry program at the National University of the Altiplano of Puno. Materials and methods: Observational cross-sectional cohort study with the participation of 78 students, with an average age of 22.63±2.87 years, with a gender distribution of 32 men (41.0%) and 46 women (59.0%). The Hamilton rating scale was used to evaluate anxiety and depression, with an internal consistency of α = 0.88 and 0.86, respectively, and the Pittsburgh questionnaire was used to measure the sleep quality index (α = 0.87). Results: In the predictive model, the standardized ß coefficients indicate that psychological anxiety (ß = -.870; p<0.001), depression (ß = .119; p<0.05) and the development of clinical practices (ß = -0.019; p<0.05) were the factors that contributed most significantly to the students' sleep quality index. Conclusion: These findings underscore the importance of addressing sleep problems as an integral part of the treatment of anxiety and depression, as well as highlighting the need to consider mental health in the assessment and management of sleep disorders.


A qualidade do sono dos estudantes é um fator essencial que influencia o correto desenvolvimento dos processos de aprendizagem cognitiva, bem como a qualidade de vida e a saúde mental e física dos futuros profissionais. Objetivo: Avaliar a relação entre ansiedade, depressão e qualidade do sono em estudantes do curso de Odontologia da Universidade Nacional do Altiplano de Puno. Materiais e métodos: Estudo de coorte transversal observacional com a participação de 78 estudantes, com idade média de 22,63±2,87 anos, com distribuição por género de 32 homens (41,0%) e 46 mulheres (59,0%). A escala de avaliação de Hamilton foi utilizada para avaliar ansiedade e depressão, com consistência interna de α = 0,88 e 0,86, respectivamente, e o questionário de Pittsburgh foi utilizado para mensurar o índice de qualidade do sono (α = 0,87). Resultados: No modelo preditivo, os coeficientes ß padronizados indicam que a ansiedade psicológica (ß = -0,870; p<0,001), a depressão (ß = 0,119; p<0,05) e o desenvolvimento de práticas clínicas (ß = -0,019; p<0,05) foram os fatores que mais contribuíram significativamente para o índice de qualidade do sono dos estudantes. Conclusão: Estas descobertas sublinham a importância de abordar os problemas do sono como parte integrante do tratamento da ansiedade e da depressão, bem como realçam a necessidade de considerar a saúde mental na avaliação e gestão dos distúrbios do sono.

15.
Small ; : e2405982, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39115088

RESUMEN

Sodium-ion batteries are increasingly recognized as ideal for large-scale energy storage applications. Alluaudite Na2+2 δFe2- δ(SO4)3 has become one of the focused cathode materials in this field. However, previous studies employing aqueous-solution synthesis often overlooked the formation mechanism of the impurity phase. In this study, the nonequilibrium evolution mechanism between Na2+2 δFe2- δ(SO4)3 and impurities by adjusting ratios of the Na2SO4/FeSO4·7H2O in the binary system is investigated. Then an optimal ratio of 0.765 with reduced impurity content is confirmed. Compared to the poor electrochemical performance of the Na2.6Fe1.7(SO4)3 (0.765) cathode, the optimized Na2.6Fe1.7(SO4)3@CNTs (0.765@CNTs) cathode, with improved electronic and ionic conductivity, demonstrates an impressive discharge specific capacity of 93.8 mAh g-1 at 0.1 C and a high-rate capacity of 67.84 mAh g-1 at 20 C, maintaining capacity retention of 71.1% after 3000 cycles at 10 C. The Na2.6Fe1.7(SO4)3@CNTs//HC full cell reaches an unprecedented working potential of 3.71 V at 0.1 C, and a remarkable mass-energy density exceeding 320 Wh kg-1. This work not only provides comprehensive guidance for synthesizing high-voltage Na2+2 δFe2- δ(SO4)3 cathode materials with controllable impurity content but also lays the groundwork of sodium-ion batteries for large-scale energy storage applications.

16.
Adv Mater ; : e2408094, 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39096074

RESUMEN

Multinuclear metal clusters are ideal candidates to catalyze small molecule activation reactions involving the transfer of multiple electrons. However, synthesizing active metal clusters is a big challenge. Herein, on constructing an unparalleled Co4(SO4)4 cluster within porphyrin-based metal-organic frameworks (MOFs) and the electrocatalytic features of such Co4(SO4)4 clusters for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is reported. The reaction of CoII sulfate and metal complexes of tetrakis(4-pyridyl)porphyrin under solvothermal conditions afforded Co4-M-MOFs (M═Co, Cu, and Zn). Crystallographic studies revealed that these Co4-M-MOFs have the same framework structure, having the Co4(SO4)4 clusters connected by metalloporphyrin units through Co─Npyridyl bonds. In the Co4(SO4)4 cluster, the four CoII ions are chemically and symmetrically equivalent and are each coordinated with four sulfate O atoms to give a distorted cube-like structure. Electrocatalytic studies showed that these Co4-M-MOFs are all active for electrocatalytic OER and ORR. Importantly, by regulating the activity of the metalloporphyrin units, it is confirmed that the Co4(SO4)4 cluster is active for oxygen electrocatalysis. With the use of Co porphyrins as connecting units, Co4-Co-MOF displays the highest electrocatalytic activity in this series of MOFs by showing a 10 mA cm-2 OER current density at 357 mV overpotential and an ORR half-wave potential at 0.83 V versus reversible hydrogen electrode (RHE). Theoretical studies revealed the synergistic effect of two proximal Co atoms in the Co4(SO4)4 cluster in OER by facilitating the formation of O─O bonds. This work is of fundamental significance to present the construction of Co4(SO4)4 clusters in framework structures for oxygen electrocatalysis and to demonstrate the cooperation between two proximal Co atoms in such clusters during the O─O bond formation process.

17.
J Korean Med Sci ; 39(30): e218, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39106887

RESUMEN

BACKGROUND: Recent studies have reported the burden of attention deficit hyperactivity disorder [ADHD], autism spectrum disorder [ASD], and depressive disorder. Also, there is mounting evidence on the effects of environmental factors, such as ambient air pollution, on these disorders among children and adolescents. However, few studies have evaluated the burden of mental disorders attributable to air pollution exposure in children and adolescents. METHODS: We estimated the risk ratios of major mental disorders (ADHD, ASD, and depressive disorder) associated with air pollutants among children and adolescents using time-series data (2011-2019) obtained from a nationwide air pollution monitoring network and healthcare utilization claims data in the Republic of Korea. Based on the estimated risk ratios, we determined the population attributable fraction (PAF) and calculated the medical costs of major mental disorders attributable to air pollution. RESULTS: A total of 33,598 patients were diagnosed with major mental disorders during 9 years. The PAFs for all the major mental disorders were estimated at 6.9% (particulate matter < 10 µm [PM10]), 3.7% (PM2.5), and 2.2% (sulfur dioxide [SO2]). The PAF of PM10 was highest for depressive disorder (9.2%), followed by ASD (8.4%) and ADHD (5.2%). The direct medical costs of all major mental disorders attributable to PM10 and SO2 decreased during the study period. CONCLUSION: This study assessed the burden of major mental disorders attributable to air pollution exposure in children and adolescents. We found that PM10, PM2.5, and SO2 attributed 7%, 4%, and 2% respectively, to the risk of major mental disorders among children and adolescents.


Asunto(s)
Contaminación del Aire , Trastorno por Déficit de Atención con Hiperactividad , Material Particulado , Humanos , Niño , Adolescente , República de Corea/epidemiología , Contaminación del Aire/efectos adversos , Material Particulado/efectos adversos , Material Particulado/análisis , Masculino , Femenino , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Trastorno por Déficit de Atención con Hiperactividad/etiología , Exposición a Riesgos Ambientales/efectos adversos , Trastornos Mentales/epidemiología , Trastornos Mentales/etiología , Trastorno del Espectro Autista/epidemiología , Trastorno del Espectro Autista/etiología , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Dióxido de Azufre/efectos adversos , Dióxido de Azufre/análisis , Preescolar , Factores de Riesgo , Costos de la Atención en Salud
18.
Eur J Cancer ; 209: 114259, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39111206

RESUMEN

BACKGROUND: HER2 is a key biomarker for breast cancer treatment and prognosis. Traditional assessment methods like immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are effective but costly and time-consuming. Our model incorporates these methods alongside photoacoustic imaging to enhance diagnostic accuracy and provide more comprehensive clinical insights. MATERIALS AND METHODS: A total of 301 breast tumors were included in this study, divided into HER2-positive (3+ or 2+ with gene amplification) and HER2-negative (below 3+ and 2+ without gene amplification) groups. Samples were split into training and validation sets in a 7:3 ratio. Statistical analyses involved t-tests, chi-square tests, and rank-sum tests. Predictive factors were identified using univariate and multivariate logistic regression, leading to the creation of three models: ModA (clinical factors only), ModB (clinical plus ultrasound factors), and ModC (clinical, ultrasound, and photoacoustic imaging-derived oxygen saturation (SO2)). RESULTS: The area under the curve (AUC) for ModA was 0.756 (95 % CI: 0.69-0.82), ModB increased to 0.866 (95 % CI: 0.82-0.91), and ModC showed the highest performance with an AUC of 0.877 (95 % CI: 0.83-0.92). These results indicate that the comprehensive model combining clinical, ultrasound, and photoacoustic imaging data (ModC) performed best in predicting HER2 expression. CONCLUSION: The findings suggest that integrating clinical, ultrasound, and photoacoustic imaging data significantly enhances the accuracy of predicting HER2 expression. For personalised breast cancer treatment, the integrated model could provide a comprehensive and reproducible decision support tool.


Asunto(s)
Neoplasias de la Mama , Nomogramas , Técnicas Fotoacústicas , Receptor ErbB-2 , Humanos , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Técnicas Fotoacústicas/métodos , Receptor ErbB-2/metabolismo , Receptor ErbB-2/análisis , Persona de Mediana Edad , Adulto , Anciano , Biomarcadores de Tumor/metabolismo , Biomarcadores de Tumor/análisis , Ultrasonografía Mamaria/métodos , Valor Predictivo de las Pruebas
19.
Environ Sci Technol ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39138907

RESUMEN

Hitherto, sulfur poisoning and hydrothermal aging have still been the challenges faced in practical applications of the Cu-SSZ-13 catalyst for the selective catalytic reduction (SCR) of NOx from diesel engine exhaust. Here, we elaborately design and conduct an in-depth investigation of the synthetic effects of hydrothermal aging and SO2 poisoning on pristine Cu-SSZ-13 and Cu-SSZ-13@Ce0.75Zr0.25O2 core@shell structure catalysts (Cu@CZ). It has been discovered that Cu@CZ susceptible to 750 °C with 5 vol % H2O followed by 200 ppm SO2 with 5 vol % H2O (Cu@CZ-A-S) could still maintain nearly 100% NOx conversion across the significantly wider temperature region of 200-425 °C, which is remarkably broader than that of the Cu-SSZ-13-A-S (300-400 °C) counterpart. The experimental results show that the hydrothermal aging process results in the migration of highly active Cu species within the cage of Cu-SSZ-13 to the CZ surface, forming CuO/CZ with abundant interfaces, which significantly enhances the adsorption and subsequent activation of NO, leading to the generation of reactive N2O3 and HONO intermediates. Moreover, density functional theory (DFT) calculations reveal that the H of the HONO* species can function as Brønsted acid sites, effectively adsorbing NH3 to generate the active NH4NO2* intermediate, which readily decomposes into N2 and H2O. Furthermore, this pathway is the rate-determining step with an energy barrier of 0.93 eV, notably lower than that of the "standard SCR" pathway (1.42 eV). Therefore, the formation of the new CuO/CZ interface profoundly boosts the low-temperature NH3-SCR activity and improves the coresistance of the Cu@CZ catalyst to sulfur poisoning and hydrothermal aging.

20.
Chemosphere ; 364: 143101, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39151575

RESUMEN

Short-term ambient fine particulate matter (PM2.5) exposure has been related to an increased risk of myocardial infarction (MI) death, but which PM2.5 constituents are associated with MI death and to what extent remain unclear. We aimed to explore the associations of short-term exposure to PM2.5 constituents with MI death and evaluate excess mortality. We conducted a time-stratified case-crossover study on 237,492 MI decedents in Jiangsu province, China during 2015-2021. Utilizing a validated PM2.5 constituents grid dataset at 1 km spatial resolution, we estimated black carbon (BC), organic carbon (OC), sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and chloride (Cl-) exposure by extracting daily concentrations grounding on the home address of each subject. We employed conditional logistic regression models to evaluate the exposure-response relationship between PM2.5 constituents and MI death. Overall, per interquartile range (IQR) increase of BC (lag 06-day; IQR: 1.75 µg/m3) and SO42- (lag 04-day; IQR: 5.06 µg/m3) exposures were significantly associated with a 3.91% and 2.94% increase in odds of MI death, respectively, and no significant departure from linearity was identified in the exposure-response curves for BC and SO42-. If BC and SO42- exposures were reduced to theoretical minimal risk exposure concentration (0.89 µg/m3 and 1.51 µg/m3), an estimate of 4.55% and 4.80% MI deaths would be avoided, respectively. We did not find robust associations of OC, NO3-, NH4+, and Cl- exposures with MI death. Individuals aged ≥80 years were more vulnerable to PM2.5 constituent exposures in MI death (p for difference <0.05). In conclusion, short-term exposure to PM2.5-bound BC and SO42- was significantly associated with increased odds of MI death and resulted in extensive excess mortality, notably in older adults. Our findings emphasized the necessity of reducing toxic PM2.5 constituent exposures to prevent deaths from MI and warranted further studies on the relative contribution of specific constituents.

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