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1.
J Environ Sci (China) ; 147: 714-725, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003084

RESUMO

In this study, an efficient stabilizer material for cadmium (Cd2+) treatment was successfully prepared by simply co-milling olivine with magnesite. Several analytical methods including XRD, TEM, SEM and FTIR, combined with theoretical calculations (DFT), were used to investigate mechanochemical interfacial reaction between two minerals, and the reaction mechanism of Cd removal, with ion exchange between Cd2+ and Mg2+ as the main pathway. A fixation capacity of Cd2+ as high as 270.61 mg/g, much higher than that of the pristine minerals and even the individual/physical mixture of milled olivine and magnesite, has been obtained at optimized conditions, with a neutral pH value of the solution after treatment to allow its direct discharge. The as-proposed Mg-based stabilizer with various advantages such as cost benefits, green feature etc., will boosts the utilization efficiency of natural minerals over the elaborately prepared adsorbents.


Assuntos
Cádmio , Compostos de Ferro , Compostos de Magnésio , Silicatos , Poluentes Químicos da Água , Cádmio/química , Poluentes Químicos da Água/química , Compostos de Magnésio/química , Silicatos/química , Compostos de Ferro/química , Adsorção , Modelos Químicos , Purificação da Água/métodos
2.
J Environ Sci (China) ; 148: 489-501, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39095183

RESUMO

The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process, which is the first step of new particle formation (NPF). In the present study, cycloaddition reaction mechanism of sulfur trioxide (SO3) to hydrogen sulfide (H2S) which is a typical air pollutant and toxic gas detrimental to the environment were comprehensively investigate through theoretical calculations and Atmospheric Cluster Dynamic Code simulations. Gas-phase stability and nucleation potential of the product thiosulfuric acid (H2S2O3, TSA) were further analyzed to evaluate its atmospheric impact. Without any catalysts, the H2S + SO3 reaction is infeasible with a barrier of 24.2 kcal/mol. Atmospheric nucleation precursors formic acid (FA), sulfuric acid (SA), and water (H2O) could effectively lower the reaction barriers as catalysts, even to a barrierless reaction with the efficiency of cis-SA > trans-FA > trans-SA > H2O. Subsequently, the gas-phase stability of TSA was investigated. A hydrolysis reaction barrier of up to 61.4 kcal/mol alone with an endothermic isomerization reaction barrier of 5.1 kcal/mol under the catalytic effect of SA demonstrates the sufficient stability of TSA. Furthermore, topological and kinetic analysis were conducted to determine the nucleation potential of TSA. Atmospheric clusters formed by TSA and atmospheric nucleation precursors (SA, ammonia NH3, and dimethylamine DMA) were thermodynamically stable. Moreover, the gradually decreasing evaporation coefficients for TSA-base clusters, particularly for TSA-DMA, suggests that TSA may participate in NPF where the concentration of base molecules are relatively higher. The present new reaction mechanism may contributes to a better understanding of atmospheric sulfur cycle and NPF.


Assuntos
Poluentes Atmosféricos , Sulfeto de Hidrogênio , Modelos Químicos , Sulfeto de Hidrogênio/química , Poluentes Atmosféricos/química , Reação de Cicloadição , Atmosfera/química , Óxidos de Enxofre/química , Cinética , Enxofre/química
3.
Pediatr Dermatol ; 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39112433

RESUMO

We report a 12-month-old boy with a skin eruption that developed 15 days after receiving the measles, mumps, rubella (MMR), pneumococcal, and meningococcal vaccines, consistent with the diagnosis of Wells syndrome. Patch testing showed a positive reaction to gelatin, which is used as a stabilizer for both live and inactivated vaccines. Gelatin was only present in the MMR vaccine.

4.
Bull Math Biol ; 86(9): 117, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39112686

RESUMO

In this study we employ computational methods to investigate the influence of aeration strategies on simultaneous nitrification-denitrification processes. Specifically, we explore the impact of periodic and intermittent aeration on denitrification rates, which typically lag behind nitrification rates under identical environmental conditions. A two-dimensional deterministic multi-scale model is employed to elucidate the fundamental processes governing the behavior of membrane aerated biofilm reactors (MABRs). We aim to identify key factors that promote denitrification under varying aeration strategies. Our findings indicate that the concentration of oxygen during the off phase and the duration of the off interval play crucial roles in controlling denitrification. Complete discontinuation of oxygen is not advisable, as it inhibits the formation of anaerobic heterotrophic bacteria, thereby impeding denitrification. Extending the length of the off interval, however, enhances denitrification. Furthermore, we demonstrate that the initial inoculation of the substratum (membrane in this study) influences substrate degradation under periodic aeration, with implications for both nitrification and denitrification. Comparison between continuous and periodic/intermittent aeration scenarios reveals that the latter can extend the operational cycle of MABRs. This extension is attributed to relatively low biofilm growth rates associated with non-continuous aeration strategies. Consequently, our study provides a comprehensive understanding of the intricate interplay between aeration strategies and simultaneous nitrification-denitrification in MABRs. The insights presented herein can contribute significantly to the optimization of MABR performance in wastewater treatment applications.


Assuntos
Biofilmes , Reatores Biológicos , Simulação por Computador , Desnitrificação , Conceitos Matemáticos , Membranas Artificiais , Modelos Biológicos , Nitrificação , Oxigênio , Desnitrificação/fisiologia , Reatores Biológicos/microbiologia , Biofilmes/crescimento & desenvolvimento , Oxigênio/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia
5.
Adv Mater ; : e2407717, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113326

RESUMO

The design of a low-iridium-loading anode catalyst layer with high activity and durability is a key challenge for a proton exchange membrane water electrolyzer (PEMWE). Here, the synthesis of a novel supported IrO2 nanocatalyst with a tri-layered structure, dubbed IrO2@TaOx@TaB that is composed of ultrasmall IrO2 nanoparticles anchored on amorphous TaOx overlayer of TaB nanorods is reported. The composite electrocatalyst shows great activity and stability toward the oxygen evolution reaction (OER) in acid, thanks to its dual-interface structural feature. The electronic interaction in IrO2/TaOx interface can regulate the coverage of surface hydroxyl groups, the Ir3+/ Ir4+ ratio, and the redox peak potential of IrO2 for enhancing OER activity, while the dense TaOx overlayer can prevent further oxidation of TaB substrate and stabilize the IrO2 catalytic layers for improving structural stability during OER. The IrO2@TaOx@TaB can be used to fabricate an anode catalyst layer of PEMWE with an iridium-loading as low as 0.26 mg cm-2. The low-iridium-loading PEMWE delivers high current densities at low cell voltages (e.g., 3.9 A cm-2@2.0 V), and gives excellent activity retention for more than 1500 h at 2.0 A cm-2 current density.

6.
Small ; : e2402200, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113350

RESUMO

NiMo alloys are considered highly promising non-noble Hydrogen Evolution Reaction (HER) catalysts. Besides the synergistic effect of alloying elements, recent attention is drawn to the Mo leaching from the catalyst. This work investigates the role of Mo in NiMo alloys during HER, aiming to understand the interplay between compositional, structural, and electronic factors on the activity, and their effects on the electrode material and catalyst properties. For this purpose, sputter-deposited low roughness NixMo100-x thin films are produced. The investigation of catalyst performance depending on their chemical composition shows a volcano-shaped plot, peaking for the Ni65Mo35 alloy with the highest intrinsic activity in alkaline HER. A comprehensive electrode surface analysis combining transmission electron microscopy, X-ray photoelectron spectroscopy and atomic force microscopy identifies the leaching of Mo on a structural level and indicates the formation of a Ni(OH)2-rich surface area. The ultimate surface characteristics of the NiMo catalysts depend on the initial composition and the electrochemical procedure. Based on the findings, it conclude that the observed catalytic properties of NiMo alloys in HER are determined by a complex interplay of increasing roughness, available surface species and their synergies. The leaching of Mo has a proven structural effect and is considered one of several factors contributing to the enhanced catalyst activity.

7.
ACS Nano ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39114966

RESUMO

Designing a high-performing iridium (Ir) single-atom catalyst is desired for acidic water electrolysis, which shows enormous potential given its high catalytic activity toward acidic oxygen evolution reaction (OER) with minimum usage of precious Ir metal. However, it still remains a substantial challenge to stabilize the Ir single atoms during the OER operation without sacrificing the activity. Here, we report a high-performing OER catalyst by immobilizing Ir single atoms on a polyimide support, which exhibits a high mass activity on a carbon paper electrode while simultaneously achieving outstanding stability with negligible decay for 360 h. The resulting electrode (denoted as Ir1-PI@CP) reaches a 49.7-fold improvement in mass activity compared to the counterpart electrode prepared without polyimide support. Both our experimental and theoretical results suggest that, owing to the strong metal-support interactions, the polyimide support can enhance the Ir 5d states of Ir single atoms in Ir1-PI@CP, which can tailor the adsorption energies of intermediates and decrease the thermodynamic barrier at the rate-determining step of the OER, but also facilitate the proton-electron-transfer process and improve the reaction kinetics. This work offers an alternative avenue for developing single-atom catalysts with superior activity and durability toward various catalytic systems and beyond.

8.
Small ; : e2404689, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115098

RESUMO

Efficient and stable catalysts are in high demand for accelerating the oxygen evolution reaction (OER). Herein, a high-entropy sulfide (HES) of (FeCoNiCrCuAl)S@HCS with a 3D structure is successfully prepared by utilizing a simple one-step solvothermal method and employed as catalyst toward OER. The lower electronegativity of Al compared to the other metal elements and its anti-corrosion character enable an outstanding OER performance of (FeCoNiCrCuAl)S@HCS with an overpotential of 253 mV at 10 mA cm-2 and an excellent durability after 20 000 CV cycles, outperforming the commercial RuO2 and most reported metal-sulfide catalysts. Experiments coupled with theoretical calculations reveal that Al atom primarily serves as electron donor and promotes a redistribution of local electrons from Co and Cr toward adjacent Fe, Ni, and Cu sites. As a result, the Cr-Al site possesses a lowest energy barrier during the rate-determining step and works as the dominant active site for OER process. This study provides a novel insight and strategy into structural design and performance enhancement for HES materials.

9.
Artigo em Inglês | MEDLINE | ID: mdl-39115165

RESUMO

Cooperative CO2 photoreduction with tailored organic synthesis offers a potent avenue for harnessing concurrently generated electrons and holes, facilitating the creation of both solar fuels and specialized chemical compounds. However, controlling the crystallization and morphologies of metal-free molecular nanostructures with exceptional photocatalytic activities toward CO2 reduction remains a significant challenge. These hurdles encompass insufficient CO2 activation potential, sluggish multielectron processes, delayed charge-separation kinetics, inadequate storage of long-lived photoexcitons, unfavorable thermodynamic conditions, and the precise control of product selectivity. Here, melem oligomer 2D nanosheets (MNSs) synthesized through pyrolysis are transformed into 1D nanorods (MNRs) at room temperature with the simultaneous engineering of vacancies and morphology. Transient absorption spectral analysis reveals that vacancies in MNRs trap charges, extending charge carrier lifetimes. Additionally, carbon vacancies enhance CO2 adsorption by increasing amine functional centers. The photocatalytic performance of MNRs for CO2 reduction coupled with benzyl alcohol oxidation is approximately ten times higher (CH3OH and aromatic aldehyde production rate 27 ± 0.5 and 93 ± 0.5 mmol g-1 h-1, respectively) than for the MNSs (CH3OH and aromatic aldehyde production rate 2.9 ± 0.5 and 9 ± 0.5 mmol g-1 h-1, respectively). The CO2 reduction pathway involved the carbon-coordinated formyl pathway through the formation of *COOH and *CHO intermediates, as mapped by in situ Fourier-transform infrared spectroscopy. The superior performance of MNRs is attributed to favorable energy-level alignment, enriched amine surfaces, and unique morphology, enhancing solar-to-chemical conversion.

10.
Angew Chem Int Ed Engl ; : e202410396, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115462

RESUMO

The pursuit of carbon-neutral energy has intensified the interest in green hydrogen production from direct seawater electrolysis, given the scarcity of freshwater resources. While Ni-based catalysts are known for their robust activity in alkaline water oxidation, their catalytic sites are prone to rapid degradation in the chlorine-rich environments of seawater, leading to limited operation time. Herein, we report a Ni(OH)2 catalyst interfaced with laser-ablated LiFePO4 (Ni(OH)2/L-LFP), derived from spent Li-ion batteries (LIBs), as an effective and stable electrocatalyst for direct seawater oxidation. Our comprehensive analyses reveal that the PO43- species, formed around L-LFP, effectively repels Cl- ions during seawater oxidation, mitigating corrosion. Simultaneously, the interface between in situ generated NiOOH and Fe3(PO4)2 enhances OH- adsorption and electron transfer during the oxygen evolution reaction. This synergistic effect leads to a low overpotential of 237 mV to attain a current density of 10 mA cm-2 and remarkable durability, with only a 3.3 % activity loss after 600 h at 100 mA cm-2 in alkaline seawater. Our findings present a viable strategy for repurposing spent LIBs into high-performance catalysts for sustainable seawater electrolysis, contributing to the advancement of green hydrogen production technologies.

11.
Cureus ; 16(7): e63747, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39099995

RESUMO

INTRODUCTION: Rickettsiae comprise a family of obligate intracellular short gram-negative coco-bacilli and are transmitted by insects, mites, fleas, louse, and tick vectors. Scrub typhus, north-Asian tick typhus, rickettsia pox, and boutonniere fevers are common in India and Asia. In the early phase of illness during the initial five days, all these are indistinguishable among themselves; also, they mimic any other self-limiting viral fever. Patients usually present with fever, headache, myalgia, malaise, nausea, vomiting, and anorexia. Rarely do patients present with rash, or give a history of exposure to animals or tick bite. Thus, rickettsial diseases are missed in the early phase, when they are easily treatable, due to lack of suspicion. AIMS AND OBJECTIVES: To study clinical features, investigations, outcomes, and factors affecting the outcome of rickettsial fever. MATERIALS AND METHODS: This was an observational study conducted from December 2012 to November 2014 in a tertiary care hospital. The study population consisted of patients above the age of 13 years with a history of any one or more of the following: fever, headache, jaundice, altered sensorium, renal dysfunction, tick bite, a farmer by occupation, exposure to cattle or sheep or dog, multiorgan failure; with serological evidence of rickettsial infection by Weil-Felix test (ox-19/ox-2/ox-k ≥ 1:320) or rickettsial antibody IgM ≥ 1.1) or PCR positive. A sample size of 40 was considered for the final analysis of this study. Statistical analysis was done using inferential statistical tests such as the chi-square test and odds ratio (OR). RESULT: The most common presenting symptom was fever (100%) seen in almost every patient followed by body aches (72.5%), joint pain (62.5%), and jaundice (62.5%). General examination showed icterus (37.5%), hypotension (30%), edema (22.5%), lymphadenopathy (22.5%), and pallor (15%). On the day of admission, 17 patients were found to have the Weil-Felix test positive with an OR of 0.538462 (CI = 0.151-1.917), while the Weil-Felix test done in the second week was positive in 37 patients with an OR of 5.4 (CI = 0.439-63.11). Rickettsial antibodies were positive only in three patients on the day of admission with an OR of 0.381 (CI = 0.0317-4.58), while in the second week, rickettsial antibodies were positive in 27 patients with an OR of 16.25. The rickettsial PCR test was positive in 13 patients with an OR of 1.48 (CI = 0.3857-5.722). The mortality rate was significantly high in patients presenting with breathlessness and respiratory complications like pneumonia, pulmonary edema, and acute respiratory distress syndrome. Similarly, patients presented with hypotension and required Ionotropic support had a high mortality rate. CONCLUSION:  While the clinical presentation of rickettsia infection is similar, the causative species and epidemiology can vary depending on the region. It is important to recognize both the typical symptoms and the epidemiology of a given region to correctly diagnose and treat these infections promptly, as they can be associated with significant morbidity and mortality. Through this study, we attempt to bring awareness about this disease which would help clinicians to suspect and start treatment at the earliest before complications set in.

12.
Heliyon ; 10(14): e33976, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39100437

RESUMO

Drug hypersensitivities are common reactions due to immunologic responses. They are of utmost importance because they may generate severe and fatal outcomes. Some drugs may cause Adverse Drug Reactions (ADRs), such as drug hypersensitivity reactions (DHRs), which can occur due to the interaction of intact drugs or their metabolites with Human Leukocyte Antigens (HLAs) and T cell receptors (TCRs). This type develops over a period of 24-72 h after exposure and is classified as type IV of DHRs. Acute generalized exanthematic pustulosis (AGEP), Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) are types of Severe Cutaneous Adverse Reactions (SCARs). In this review, we aim to discuss the types of ADRs, the mechanisms involved in their development, and the role of immunogenetic factors, such as HLAs in type IV DHRs, single-nucleotide polymorphisms (SNPs), and some epigenetic modifications, e.g., DNA/histone methylation in a variety of genes and their promoters which may predispose subjects to DHRs. In conclusion, development of promising novel in vitro or in vivo diagnostic and prognostic markers is essential for identifying susceptible subjects or providing treatment protocols to work up patients with drug allergies as personalized medicine.

13.
Front Public Health ; 12: 1421774, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39100946

RESUMO

Background: The study aimed to evaluate the positivity rates and genotype distribution of the multiplex PCR capillary electrophoresis (MPCE) and PCR-Reverse Dot Blot (PCR-RDB) assays for human papillomavirus (HPV) detection in cervical cancer tissue specimens, and to explore their detection principles and applications in large-scale population screening. Methods: The MPCE and PCR-RDB assays were performed separately on 425 diagnosed cervical cancer tissue specimens. Subsequently, the results of both assays were compared based on the HPV infection positivity rates and genotype distribution. Results: The overall positive rates of HPV genotypes for the MPCE and PCR-RDB assays were 97.9% and 92.9%, respectively. A p-value < 0.001 indicated a statistically significance difference in consistency between the two assays. The kappa value was 0.390, indicating that the consistency between both assays was fair. HPV16 was the most common single-genotype infection type, with infection rates detected via MPCE and PCR-RDB assays being 75.7% and 68.3%, respectively. In the age group >50 years, the HPV multiple-type infection rate detected via MPCE assay was significantly higher than that detected by the PCR-RDB assay, with a statistically significant difference (p = 0.002). Conclusion: To reduce the false-negative rate and improve screening efficiency, the MPCE assay, which targets the oncogenic gene E6/E7 segments, can be extended to the general female population for the early detection, diagnosis, and treatment of cervical cancer.


Assuntos
DNA Viral , Eletroforese Capilar , Genótipo , Reação em Cadeia da Polimerase Multiplex , Papillomaviridae , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/virologia , Neoplasias do Colo do Útero/diagnóstico , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex/métodos , Adulto , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , DNA Viral/genética , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/virologia , Técnicas de Genotipagem/métodos , Idoso , Reação em Cadeia da Polimerase/métodos , Papillomavirus Humano
14.
Oncol Lett ; 28(4): 452, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39101001

RESUMO

Although the efficacy of treatment strategies for cancer have been improving steadily over the past decade, the adverse event profile following such treatments has also become increasingly complex. The present report described the case of a 67-year-old male patient with gastric stump carcinoma with liver invasion. The patient was treated with oxaliplatin and capecitabine (CAPEOX regimen) chemotherapy, combined with the programmed cell death protein-1 (PD-1) inhibitor tislelizumab. Following treatment, the patient suffered from chills, high fever and facial flushing, followed by shock. Relevant examination results revealed severe multiple organ damage, as well as a significant elevation in IL-6 and procalcitonin (PCT) levels. Initially, the patient was diagnosed with either immune-related adverse events (irAEs) associated with cytokine release syndrome caused by tislelizumab or severe bacterial infection. However, when tislelizumab treatment was stopped and the CAPEOX chemotherapy regimen was reapplied, similar symptoms recurred. Following screening, it was finally determined that severe hypersensitivity reaction (HSR) caused by oxaliplatin was the cause underlying these symptoms. A literature review was then performed, which found that severe oxaliplatin-related HSR is rare, rendering the present case atypical. The present case exhibited no common HSR symptoms, such as cutaneous and respiratory symptoms. However, the patient suffered from serious multiple organ damage, which was misdiagnosed as irAE when oxaliplatin chemotherapy combined with the PD-1 inhibitor was administered. In addition, this apparent severe oxaliplatin-related HSR caused a significant increase in PCT levels, which was misdiagnosed as severe bacterial infection and prevented the use of glucocorticoids. This, in turn, aggravated the damage in this patient.

15.
J Adv Vet Anim Res ; 11(2): 474-482, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39101100

RESUMO

Objective: Bovine viral diarrhea (BVD) disease is a viral infection in cows caused by a single-stranded plus-sense RNA virus of the Pestivirus genus under the Flaviviridae family. The clinical manifestation of BVD mainly includes diarrhea and immunosuppression, thereby exacerbating various respiratory diseases. This study was conducted to detect and molecularly characterize the bovine viral diarrhea disease virus (BVDV) in cattle on selected farms in Selangor, Malaysia. Materials and Methods: A reverse transcription polymerase chain reaction (RT-PCR) was performed for antigen detection in 253 plasma samples collected from cows using a cross-sectional study design. We selected the 5 untranslated regions (5'-UTR) region and the E2 region to compare the genetic differences between the isolates. Results: One sample was found to be positive (1/253) following RT-PCR targeting the conserved 5'-UTR region of BVDV. Thus, BVDV antigen prevalence was 0.40% (95% confidence interval: 0.0%-2.2%). By targeting the hypervariable E2 region of the isolated virus, UPM/MAL/BVDV/D17, the virus was classified under the subgenotype BVDV-1a. Conclusion: BVDV is present and circulating on selected cattle farms in Selangor, Malaysia. Given the presence of BVDV in several subgenotypes, the screening of all incoming cattle at Malaysia's border is pertinent to prevent the entry of other BVDV subgenotypes into the country.

16.
Nano Lett ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39102442

RESUMO

Thickness control of two-dimensional (2D) metal nanosheets (metallenes) has scientific significance for energy and catalyst applications, yet is unexplored owing to the lack of an efficient approach for the tailored synthesis of metallenes with controlled atomic layers. Here we report a 2D template-directed synthesis of ultrathin Pd nanosheets with well-controlled thicknesses. Molecularly thin single-crystalline Pd nanosheets with well-defined hexagonal morphologies were synthesized via a one-pot method with 2,4,6-trichlorophenyl formate. Such Pd nanosheets were used as hard templates for the tailored synthesis of the Pd nanosheets with controlled thicknesses (9, 11, 13, and 15 atomic layers). Hard X-ray photoelectron spectroscopy and density functional theory calculations revealed unique electronic states in thickness-controlled Pd nanosheets; these states included reduced surface charges to bulk, increased work functions, and decreased d-band centers. Thus, atomic layer engineering of Pd nanosheets enabled the fine-tuning of the surface electronic states to improve the hydrogen evolution reaction.

17.
ACS Appl Bio Mater ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39103296

RESUMO

Sensitive detection of cardiac troponin I (cTnI) is of great significance in the diagnosis of a fatal acute myocardial infarction. A redox-active nanocomposite of copper(II)-tannic acid@Cu (CuTA@Cu) was herein prepared on the surface of a glassy carbon electrode by electrochemical deposition of metallic copper combined with a metal stripping strategy. Then, HAuCl4 was in situ reduced to gold nanoparticles (AuNPs) by strong reductive catechol groups in the TA ligand. The AuNPs/CuTA@Cu composite was further utilized as a bifunctional matrix for the immobilization of the cTnI antibody (anti-cTnI), producing an electrochemical immunosensor. Electrochemical tests show that the immunoreaction between anti-cTnI and target cTnI can cause a significant reduction of the electrochemical signal of CuTA@Cu. It can be attributed to the insulating characteristic of the immunocomplex and its barrier effect to the electrolyte ion diffusion. From the signal changes of CuTA@Cu, cTnI can be analyzed in a wide range from 10 fg mL-1 to 10 ng mL-1, with an ultralow detection limit of 0.65 fg mL-1. The spiked recovery assays show that the immunosensor is reliable for cTnI determination in human serum samples, demonstrating its promising application in the early clinical diagnosis of myocardial infarction.

18.
Environ Sci Technol ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39104092

RESUMO

Developing robust metal-based monolithic catalysts with efficient oxygen activation capacity is crucial for thermal catalytic treatment of volatile organic compound (VOC) pollution. Two-dimensional (2D) metal oxides are alternative thermal catalysts, but their traditional loading strategies on carriers still face challenges in practical applications. Herein, we propose a novel in situ molten salt-loading strategy that synchronously enables the construction of 2D Co3O4 and its growth on Fe foam for the first time to yield a unique monolithic catalyst named Co3O4/Fe-S. Compared to the Co3O4 nanocube-loaded Fe foam, Co3O4/Fe-S exhibits a significantly improved catalytic performance with a temperature reduction of 44 °C at 90% toluene conversion. Aberration-corrected scanning transmission electron microscopy and theoretical calculation suggest that Co3O4/Fe-S possesses abundant 2D Co3O4/Fe3O4 composite interfaces, which promote the construction of active sites (oxygen vacancy and Co3+) to boost oxygen activation and toluene chemisorption, thereby accelerating the transformation of reaction intermediates through Langmuir-Hinshelwood (L-H) and Mars-van Krevelen (MvK) mechanisms. Moreover, the growth mechanism reveals that 2D Co3O4/Fe3O4 composite interfaces are generated in situ in molten salt, inducing the growth of 2D Co3O4 onto the surface lattice of 2D Fe3O4. This study provides new insights into enhancing oxygen activation and opens an unprecedented avenue in preparing efficient monolithic catalysts for VOC oxidation.

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