Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Nano Lett ; 24(15): 4537-4545, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38568783

RESUMEN

An interfacial solar steam generation evaporator for seawater desalination has attracted extensive interest in recent years. Nevertheless, challenges still remain in relatively low evaporation rate, unsatisfactory energy conversion efficiency, and salt accumulation. Herein, we have demonstrated a biomimetic bilayer composite aerogel consisting of bottom hydrophilic and vertically aligned EVOH channels and an upper hydrophobic conical Fe3O4 array. Thanks to the design merits, the 3D Fe3O4/V-EVOH evaporator exhibits a high evaporation rate of ∼2.446 kg m-2 h-1 and an impressive solar energy conversion efficiency of ∼165.5% under 1 sun illumination, which is superior to those of state-of-the-art evaporators reported so far. Moreover, the asymmetrical wettability not only allows the evaporator to self-float on the water but also facilitates the salt ion diffusion in the channels; thus, the evaporator shows no salt crystals on its surface and only a 6% decrease in evaporation performance even after the salt concentration increases from 0 to 10.0 wt %.

2.
J Am Chem Soc ; 146(15): 10934-10942, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38581437

RESUMEN

Hydroxylamine (HA, NH2OH) is a critical feedstock in the production of various chemicals and materials, and its efficient and sustainable synthesis is of great importance. Electroreduction of nitrate on Cu-based catalysts has emerged as a promising approach for green ammonia (NH3) production, but the electrosynthesis of HA remains challenging due to overreduction of HA to NH3. Herein, we report the first work on ketone-mediated HA synthesis using nitrate in water. A metal-organic-framework-derived Cu catalyst was developed to catalyze the reaction. Cyclopentanone (CP) was used to capture HA in situ to form CP oxime (CP-O) with C═N bonds, which is prone to hydrolysis. HA could be released easily after electrolysis, and CP was regenerated. It was demonstrated that CP-O could be formed with an excellent Faradaic efficiency of 47.8%, a corresponding formation rate of 34.9 mg h-1 cm-2, and a remarkable carbon selectivity of >99.9%. The hydrolysis of CP-O to release HA and CP regeneration was also optimized, resulting in 96.1 mmol L-1 of HA stabilized in the solution, which was significantly higher than direct nitrate reduction. Detailed in situ characterizations, control experiments, and theoretical calculations revealed the catalyst surface reconstruction and reaction mechanism, which showed that the coexistence of Cu0 and Cu+ facilitated the protonation and reduction of *NO2 and *NH2OH desorption, leading to the enhancement for HA production.

3.
Small ; : e2311659, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38747005

RESUMEN

The performance consistency of the gas sensor is strongly dependent on the interface binding between the sensitive materials and the electrodes. Traditional powder coating methods can inevitably lead to differences in terms of substrate-film interface interaction and device performance, affecting the stability and lifetime. Thus, efficient growth of sensitive materials on device substrates is crucial and essential to enhance the sensing performance, especially for stability. Herein, hierarchically ordered macro/mesoporous WO3 films are in situ synthesized on the electrode via a facile soft/hard dual-template strategy. Orderly arrayed uniform polystyrene (PS) microspheres with tailored size (ca. 1.2 µm) are used as a hard template, and surfactant Pluronic F127 as a soft template can co-assemble with tungsten precursor into ordered mesostructure in the interstitials of PS colloidal crystal induced by solvent evaporation. Benefiting from its rich porosity and high stability, the macro/mesoporous WO3-based sensor shows high sensitivity (Rair/Rgas = 307), fast response/recovery speed (5/9 s), and excellent selectivity (SH2S/Smax > 7) toward 50 ppm H2S gas (a biomarker for halitosis). Significantly, the sensors exhibit an extended service life with a negligible change in sensing performance within 60 days. This lab-on-device synthesis provides a platform method for constructing stable nanodevices with good consistency and high stability, which are highly desired for developing high-performance sensors.

4.
Reprod Biol Endocrinol ; 22(1): 32, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38509534

RESUMEN

STUDY QUESTION: The objective was to construct a model for predicting the probability of recurrent implantation failure (RIF) after assisted reproductive technology (ART) treatment based on the clinical characteristics and routine laboratory test data of infertile patients. A model was developed to predict RIF. The model showed high calibration in external validation, helped to identify risk factors for RIF, and improved the efficacy of ART therapy. WHAT IS KNOWN ALREADY: Research on the influencing factors of RIF has focused mainly on embryonic factors, endometrial receptivity, and immune factors. However, there are many kinds of examinations regarding these aspects, and comprehensive screening is difficult because of the limited time and economic conditions. Therefore, we should try our best to analyse the results of routine infertility screenings to make general predictions regarding the occurrence of RIF. STUDY DESIGN, SIZE, DURATION: A retrospective study was conducted with 5212 patients at the Reproductive Center of the First Affiliated Hospital of USTC from January 2018 to June 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study included 462 patients in the RIF group and 4750 patients in the control group. The patients' basic characteristics, clinical treatment data, and laboratory test indices were compared. Logistic regression was used to analyse RIF-related risk factors, and the prediction model was evaluated by receiver operating characteristic (ROC) curves and the corresponding areas under the curve (AUCs). Further analysis of the influencing factors of live births in the first cycle of subsequent assisted reproduction treatment in RIF patients was performed, including the live birth subgroup (n = 116) and the no live birth subgroup (n = 200). MAIN RESULTS AND THE ROLE OF CHANCE: (1) An increased duration of infertility (1.978; 95% CI, 1.264-3.097), uterine cavity abnormalities (2.267; 95% CI, 1.185-4.336), low AMH levels (0.504; 95% CI, 0.275-0.922), insulin resistance (3.548; 95% CI, 1.931-6.519), antinuclear antibody (ANA)-positive status (3.249; 95% CI, 1.20-8.797) and anti-ß2-glycoprotein I antibody (A-ß2-GPI Ab)-positive status (5.515; 95% CI, 1.481-20.536) were associated with an increased risk of RIF. The area under the curve of the logistic regression model was 0.900 (95% CI, 0.870-0.929) for the training cohort and 0.895 (95% CI, 0.865-0.925) for the testing cohort. (2) Advanced age (1.069; 95% CI, 1.015-1.126) was a risk factor associated with no live births after the first cycle of subsequent assisted reproduction treatment in patients with RIF. Blastocyst transfer (0.365; 95% CI = 0.181-0.736) increased the probability of live birth in subsequent cycles in patients with RIF. The area under the curve of the logistic regression model was 0.673 (95% CI, 0.597-0.748). LIMITATIONS, REASONS FOR CAUTION: This was a single-centre regression study, for which the results need to be evaluated and verified by prospective large-scale randomized controlled studies. The small sample size for the analysis of factors influencing pregnancy outcomes in subsequent assisted reproduction cycles for RIF patients resulted in the inclusion of fewer covariates, and future studies with larger samples and the inclusion of more factors are needed for assessment and validation. WIDER IMPLICATIONS OF THE FINDINGS: Prediction of embryo implantation prior to transfer will facilitate the clinical management of patients and disease prediction and further improve ART treatment outcomes. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the General Project of the National Natural Science Foundation of China (Nos. 82,201,792, 82,301,871, 81,971,446, and 82,374,212) and the Natural Science Foundation of Anhui Province (No. 2208085MH206). There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: This study was registered with the Chinese Clinical Trial Register (Clinical Trial Number: ChiCTR1800018298 ).


Asunto(s)
Infertilidad , Técnicas Reproductivas Asistidas , Embarazo , Femenino , Humanos , Estudios Retrospectivos , Estudios Prospectivos , Implantación del Embrión , Infertilidad/terapia , Nacimiento Vivo , Índice de Embarazo
5.
Inorg Chem ; 63(31): 14736-14745, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39028929

RESUMEN

While electrochemically upcycling nitrate wastes to valuable ammonia is considered a very promising pathway for tackling the environmental and energy challenges underlying the nitrogen cycle, the effective catalysts involved are mainly limited to metal-based materials. Here, we report that commercial carbon fiber paper, which is a classical current collector and is typically assumed to be electrochemically inert, can be significantly activated during the reaction. As a result, it shows a high NH3 Faradaic efficiency of 87.39% at an industrial-level current density of 300 mA cm-2 for over 90 h of continuous operation, with a NH3 production rate of as high as 1.22 mmol cm-2 h-1. Through experimental and theoretical analysis, the in situ-formed oxygen functional groups are demonstrated to be responsible for the NO3RR performance. Among them, the C-O-C group is finally identified as the active center, which lowers the thermodynamic energy barrier and simultaneously improves the hydrogenation kinetics. Moreover, high-purity NH4Cl and NH3·H2O were obtained by coupling the NO3RR with an air-stripping approach, providing an effective way for converting nitrate waste into high-value-added NH3 products.

6.
Fish Shellfish Immunol ; 148: 109521, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38552889

RESUMEN

In mammals, ß-catenin participates in innate immune process through interaction with NF-κB signaling pathway. However, its role in teleost immune processes remains largely unknown. We aimed to clarify the function of ß-catenin in the natural defense mechanism of Qi river crucian carp (Carassius auratus). ß-catenin exhibited a ubiquitous expression pattern in adult fish, as indicated by real-time PCR analysis. Following lipopolysaccharide (LPS), Polyinosinic-polycytidylic acid (polyI: C) and Aeromonas hydrophila (A. hydrophila) challenges, ß-catenin increased in gill, intestine, liver and kidney, indicating that ß-catenin likely plays a pivotal role in the immune response against pathogen infiltration. Inhibition of the ß-catenin pathway using FH535, an inhibitor of Wnt/ß-catenin pathway, resulting in pathological damage of the gill, intestine, liver and kidney, significant decrease of innate immune factors (C3, defb3, LYZ-C, INF-γ), upregulation of inflammatory factors (NF-κB, TNF-α, IL-1, IL-8), and downregulation of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities, increase of Malondialdehyde (MDA) content. Following A. hydrophila invasion, the mortality rate in the FH535 treatment group exceeded that of the control group. In addition, the diversity of intestinal microflora decreased and the community structure was uneven after FH535 treatment. In summary, our findings strongly suggest that ß-catenin plays a vital role in combating pathogen invasion and regulating intestinal flora in Qi river crucian carp.


Asunto(s)
Carpas , Enfermedades de los Peces , Microbioma Gastrointestinal , Infecciones por Bacterias Gramnegativas , Sulfonamidas , Animales , Carpa Dorada/genética , Carpa Dorada/metabolismo , Carpas/genética , Carpas/metabolismo , FN-kappa B , Ríos , beta Catenina/genética , Qi , Inmunidad Innata/genética , Antioxidantes , Aeromonas hydrophila/fisiología , Proteínas de Peces , Infecciones por Bacterias Gramnegativas/veterinaria , Mamíferos/metabolismo
7.
Artículo en Inglés | MEDLINE | ID: mdl-38986533

RESUMEN

BACKGROUND AND AIM: Despite prior attempts to evaluate the effects of sarcopenia on survival among patients with colorectal cancer (CRC), the results of these studies have not been consistent. The present study aimed to evaluate the association between sarcopenia and survival among patients having CRC without distant metastasis by aggregating multiple studies. METHODS: We performed a literature search using computerized databases and identified additional studies from among the bibliographies of retrieved articles. The quality of each study was evaluated using the Newcastle-Ottawa Scale, and meta-analyses were performed to evaluate overall survival (OS) and disease-free survival (DFS). RESULTS: Thirteen studies with up to 6600 participants were included in the meta-analyses, with a mean age of 63.6 years (range: 18-93 years). We found that preoperative sarcopenia was associated with worse OS (hazard ratio [HR]: 1.61; 95% confidence interval [CI]: 1.38-1.88) and worse DFS (HR: 1.57; 95% CI: 1.10-2.24). Compared with patients without sarcopenia after tumor resection, those with postoperative sarcopenia had worse OS (HR: 1.76; 95% CI: 1.47-2.10) and DFS (HR: 1.79; 95% CI: 1.46-2.20). CONCLUSION: These meta-analyses suggest that sarcopenia, no matter observed before or after tumor resection, is associated with worse OS and DFS in patients with CRC who have no distant metastasis.

8.
Appl Microbiol Biotechnol ; 108(1): 228, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386129

RESUMEN

Fusarium verticillioides is one of the most important fungal pathogens causing maize ear and stalk rots, thereby undermining global food security. Infected seeds are usually unhealthy for consumption due to contamination with fumonisin B1 (FB1) mycotoxin produced by the fungus as a virulence factor. Unveiling the molecular factors that determine fungal development and pathogenesis will help in the control and management of the diseases. Kex2 is a kexin-like Golgi-resident proprotein convertase that is involved in the activation of some important proproteins. Herein, we identified and functionally characterized FvKex2 in relation to F. verticillioides development and virulence by bioinformatics and functional genomics approaches. We found that FvKex2 is required for the fungal normal vegetative growth, because the growth of the ∆Fvkex2 mutant was significantly reduced on culture media compared to the wild-type and complemented strains. The mutant also produced very few conidia with morphologically abnormal shapes when compared with those from the wild type. However, the kexin-like protein was dispensable for the male role in sexual reproduction in F. verticillioides. In contrast, pathogenicity was nearly abolished on wounded maize stalks and sugarcane leaves in the absence of FvKEX2 gene, suggesting an essential role of Fvkex2 in the virulence of F. verticillioides. Furthermore, high-performance liquid chromatography analysis revealed that the ∆Fvkex2 mutant produced a significantly lower level of FB1 mycotoxin compared to the wild-type and complemented strains, consistent with the loss of virulence observed in the mutant. Taken together, our results indicate that FvKex2 is critical for vegetative growth, FB1 biosynthesis, and virulence, but dispensable for sexual reproduction in F. verticillioides. The study presents the kexin-like protein as a potential drug target for the management of the devastating maize ear and stalk rot diseases. Further studies should aim at uncovering the link between FvKex2 activity and FB1 biosynthesis genes. KEY POINTS: •The kexin-like protein FvKex2 contributes significantly to the vegetative growth of Fusarium verticillioides. •The conserved protein is required for fungal conidiation and conidial morphology, but dispensable for sexual reproduction. •Deletion of FvKEX2 greatly attenuates the virulence and mycotoxin production potential of F. verticillioides.


Asunto(s)
Fumonisinas , Fusarium , Micotoxinas , Masculino , Humanos , Micotoxinas/genética , Virulencia
9.
Child Care Health Dev ; 50(3): e13270, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38706405

RESUMEN

INTRODUCTION: Chronic physical disease (CPD) makes life filled with many negative events in adolescents, but not all adolescents experiencing negative life events proceed to develop emotional distress, only those with low emotional distress tolerance (EDT). A valid and reliable scale to measure EDT in CPD adolescents is important for caring for their emotional distress. Therefore, the purpose of this study is to translate the 15-item English version Distress Tolerance Scale (DTS) into a Chinese version and then validate the scale for measuring EDT of adolescents with CPD. METHODS: The 15-item English version DTS was translated into a Chinese version using the translation guidelines for cross-cultural research. Two cohorts of adolescents with CPD were recruited from four hospitals in southern Taiwan, with the first cohort including 124 adolescents with CPD employed to conduct exploratory factor analysis, corrected item-total correlation and reliability testing, while the second cohort, consisting of 238 adolescents with CPD, was utilized to examine confirmatory factor analysis and concurrent validity. RESULTS: The two-factor nine-item Chinese version DTS for Adolescents with CPD (C-DTS-A) was developed. Lower scores of the C-DTS-A were significantly associated with higher diabetes distress, poorer self-management, and worse glycaemic control; their correlation coefficients sequentially were -.40, .17 and -.23. Cronbach's α and the test-retest reliability of the two-factor C-DTS-A ranged from .81 to .87 and from .79 to .89, respectively. CONCLUSION: The two-factor nine-item C-DTS-A with good cross-cultural translation quality was a reliable and valid scale to assess EDT for adolescents with CPD.


Asunto(s)
Comparación Transcultural , Distrés Psicológico , Psicometría , Traducciones , Humanos , Adolescente , Femenino , Masculino , Reproducibilidad de los Resultados , Enfermedad Crónica , Taiwán , Encuestas y Cuestionarios/normas , Estrés Psicológico/diagnóstico , Análisis Factorial , Traducción
10.
Int J Mol Sci ; 25(14)2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39062872

RESUMEN

Rice (Oryza sativa L.), a fundamental global staple, nourishes over half of the world's population. The identification of the ddt1 mutant in rice through EMS mutagenesis of the indica cultivar Shuhui527 revealed a dwarf phenotype, characterized by reduced plant height, smaller grain size, and decreased grain weight. Detailed phenotypic analysis and map-based cloning pinpointed the mutation to a single-base transversion in the LOC_Os03g04680 gene, encoding a cytochrome P450 enzyme, which results in a premature termination of the protein. Functional complementation tests confirmed LOC_Os03g04680 as the DDT1 gene responsible for the observed phenotype. We further demonstrated that the ddt1 mutation leads to significant alterations in gibberellic acid (GA) metabolism and signal transduction, evidenced by the differential expression of key GA-related genes such as OsGA20OX2, OsGA20OX3, and SLR1. The mutant also displayed enhanced drought tolerance, as indicated by higher survival rates, reduced water loss, and rapid stomatal closure under drought conditions. This increased drought resistance was linked to the mutant's improved antioxidant capacity, with elevated activities of antioxidant enzymes and higher expression levels of related genes. Our findings suggest that DDT1 plays a crucial role in regulating both plant height and drought stress responses. The potential for using gene editing of DDT1 to mitigate the dwarf phenotype while retaining improved drought resistance offers promising avenues for rice improvement.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Giberelinas , Mutación , Oryza , Proteínas de Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Giberelinas/metabolismo , Agua/metabolismo , Fenotipo , Sequías , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo
11.
Nurs Health Sci ; 26(3): e13137, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38981587

RESUMEN

The public's perception of the nursing image deeply influences nurses' work and professional development. However, the Taiwanese public's perception of nursing remains unclear. This study aimed to determine the validity and reliability of a Chinese version of the Nursing Image Scale (NIS) in Taiwan. This was a psychometric study using a cross-sectional survey. Participants were recruited via the snowball sampling method through the online community software LINE from August 1 to 13, 2019. After data collection, the construction and validation of the NIS to measure public opinion were assessed, including content validity, corrected item-total correlation, exploratory factor analysis (EFA), and reliability. A total of 1331 valid responses were included in the analysis. After EFA analysis, the 20 scale items were divided across the four domains of prudence and care, innovation and cooperation, efficiency and division, and professionalism and respect. The NIS (Chinese version) was valid and reliable for measuring public opinion and may be used to examine changes in public perceptions of nursing.


Asunto(s)
Percepción , Psicometría , Opinión Pública , Humanos , Taiwán , Femenino , Reproducibilidad de los Resultados , Masculino , Adulto , Estudios Transversales , Psicometría/instrumentación , Psicometría/métodos , Encuestas y Cuestionarios , Persona de Mediana Edad , Enfermería/métodos , Enfermería/normas
12.
Angew Chem Int Ed Engl ; 63(15): e202400033, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38225207

RESUMEN

Chemical manufacturing utilizing renewable sources and energy emerges as a promising path towards sustainability and carbon neutrality. The electrocatalytic reactions involving nitrogen oxides (NOx) offered a potential strategy for synthesizing various nitrogenous chemicals. However, it is currently hindered by low selectivity/efficiency and limited reaction pathways, mainly due to the difficulties in controllable generation and utilization of nitrogenous intermediates. In this minireview, focusing on nitrogenous intermediates in NOx-involved electrocatalytic reactions, we discuss newly developed methodologies for studying and controlling the generation, conversion, and utilizing of nitrogenous intermediates, which enable recent developments in NOx-involved electrocatalytic reactions that yield various products, including ammonia (NH3), organonitrogen molecules, and nitrogenous compounds exhibiting unconventional oxidation states. Furthermore, we also make an outlook to highlight future directions in the emerging field of NOx-involved electrocatalytic reactions.

13.
Angew Chem Int Ed Engl ; : e202411305, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39009482

RESUMEN

The productions of hydrogen peroxide (H2O2) and hydrogen (H2) in a photoelectrochemical (PEC) water splitting cell suffer from an onset potential that limits solar conversion efficiencies. The formation of H2O2 through two-electron PEC water oxidation reaction competes with four-electron oxidation evolution reaction. Herein, we developed the surface selenium doped antimony trisulfide photoelectrode with the integrated ruthenium cocatalyst (Ru/Sb2(S,Se)3) to achieve the low onset potential and high Faraday efficiency (FE) for selective H2O2 production. The photoanode exhibits an average FE of 85% in the potential range of 0.4-1.6 VRHE and the H2O2 yield of 1.01 µmol cm-2 min-1 at 1.6 VRHE, especially at low potentials of 0.1-0.55 VRHE with 80.4% FE. Impressively, an unassisted PEC system that employs light and electrolyte was constructed to simultaneously produce H2O2 and H2 production on both Ru/Sb2(S,Se)3 photoanode and the Pt/TiO2/Sb2S3 photocathode. The integrated system enables the average PEC H2O2 production rate of 0.637 µmol cm-2 min-1 without applying any addition bias. This is the first demonstration that Sb2S3-based photoelectrodes exhibit H2O2/H2 two-side production with a strict key factor of the system, which represents its powerful platform to achieve high efficiency and productivity and the feasibility to facilitate value-added products in neutral conditions.

14.
Angew Chem Int Ed Engl ; : e202409693, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38993073

RESUMEN

The photoelectrochemical reduction of nitrate to ammonia (PEC NO3RR) has emerged as a promising pathway for facilitating the natural nitrogen cycle. The PEC NO3RR can lower the reduction potential needed for ammonia synthesis through photogenerated voltage, showcasing the significant potential for merging abundant solar energy with sustainable nitrogen fixation. However, it is influenced by the selective photocathodes with poor carrier kinetics, low catalytic selectivity, and ammonia yields. There are few reports on suitable photoelectrodes owning efficient charge transport on PEC NO3RR at low overpotentials. Herein, we rationally constructed the CuSn alloy co-catalysts on the antimony sulfides with a highly selective PEC ammonia and an ultra-low onset potential (0.62 VRHE). CuSn/TiO2/Sb2S3 achieved an ammonia faradic efficiency of 97.82% at a low applied potential of 0.4 VRHE, and an ammonia yield of 16.96 µmol h-1 cm-2 at 0 VRHE under one sun illumination. Dynamics experiments and theoretical calculations have demonstrated that CuSn/TiO2/Sb2S3 has an enhanced charge separation and transfer efficiency, facilitating photogenerated electrons to participate in PEC NO3RR quickly. Meanwhile, moderate NO2* adsorption on this photocathode optimizes the catalytic activity and increases the NH4+ yield. This work opens an avenue for designing sulfide-based photocathodes for the efficient route of solar-to-ammonia conversion.

15.
Angew Chem Int Ed Engl ; 63(29): e202406007, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38687057

RESUMEN

While the mild production of syngas (a mixture of H2 and CO) from CO2 and H2O is a promising alternative to the coal-based chemical engineering technologies, the inert nature of CO2 molecules, unfavorable splitting pathways of H2O and unsatisfactory catalysts lead to the challenge in the difficult integration of high CO2 conversion efficiency with produced syngas with controllable H2/CO ratios in a wide range. Herein, we report an efficient plasma-driven catalytic system for mild production of pure syngas over porous metal-organic framework (MOF) catalysts with rich confined H2O molecules, where their syngas production capacity is regulated by the in situ evolved ligand defects and the plasma-activated intermediate species of CO2 molecules. Specially, the Cu-based catalyst system achieves 61.9 % of CO2 conversion and the production of pure syngas with wide H2/CO ratios of 0.05 : 1-4.3 : 1. As revealed by the experimental and theoretical calculation results, the in situ dynamic structure evolution of Cu-containing MOF catalysts favors the generation of coordinatively unsaturated metal active sites with optimized geometric and electronic characteristics, the adsorption of reactants, and the reduced energy barriers of syngas-production potential-determining steps of the hydrogenation of CO2 to *COOH and the protonation of H2O to *H.

16.
Angew Chem Int Ed Engl ; 63(22): e202404258, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38454791

RESUMEN

Engineering advantageous defects to construct well-defined active sites in catalysts is promising but challenging to achieve efficient photocatalytic NH3 synthesis from N2 and H2O due to the chemical inertness of N2 molecule. Here, we report defective Fe-based metal-organic framework (MOF) photocatalysts via a non-thermal plasma-assisted synthesis strategy, where their NH3 production capability is synergistically regulated by two types of defects, namely, bridging organic ligands and terminal inorganic ligands (OH- and H2O). Specially, the optimized MIL-100(Fe) catalysts, where there are only terminal inorganic ligand defects and coexistence of dual defects, exhibit the respective 1.7- and 7.7-fold activity enhancement comparable to the pristine catalyst under visible light irradiation. As revealed by experimental and theoretical calculation results, the dual defects in the catalyst induce the formation of abundant and highly accessible coordinatively unsaturated Fe active sites and synergistically optimize their geometric and electronic structures, which favors the injection of more d-orbital electrons in Fe sites into the N2 π* antibonding orbital to achieve N2 activation and the formation of a key intermediate *NNH in the reaction. This work provides a guidance on the rational design and accurate construction of porous catalysts with precise defective structures for high-performance activation of catalytic molecules.

17.
Angew Chem Int Ed Engl ; : e202409698, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38924667

RESUMEN

While the ambient N2 reduction to ammonia (NH3) using H2O as hydrogen source (2N2+6H2O=4NH3+3O2) is known as a promising alternative to the Haber-Bosch process, the high bond energy of N≡N bond leads to the extremely low NH3 yield. Herein, we report a highly efficient catalytic system for ammonia synthesis using the low-temperature dielectric barrier discharge plasma to activate inert N2 molecules into the excited nitrogen species, which can efficiently react with the confined and concentrated H2O molecules in porous metal-organic framework (MOF) reactors with V3+, Cr3+, Mn3+, Fe3+, Co2+, Ni2+ and Cu2+ ions. Specially, the Fe-based catalyst MIL-100(Fe) causes a superhigh NH3 yield of 22.4 mmol g-1 h-1. The investigation of catalytic performance and systematic characterizations of MIL-100(Fe) during the plasma-driven catalytic reaction unveils that the in situ generated defective Fe-O clusters are the highly active sites and NH3 molecules indeed form inside the MIL-100(Fe) reactor. The theoretical calculation reveals that the porous MOF catalysts have different adsorption capacity for nitrogen species on different catalytic metal sites, where the optimal MIL-100(Fe) has the lowest energy barrier for the rate-limiting *NNH formation step, significantly enhancing efficiency of nitrogen fixation.

18.
Angew Chem Int Ed Engl ; : e202410972, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39115031

RESUMEN

Coupling in situ generated intermediates with other substrates/intermediates is a viable approach for diversifying product outcomes of catalytic reactions involving two or multiple reactants. Cyclohexanone oxime is a key precursor for caprolactam synthesis (the monomer of Nylon-6), yet its current production uses unsustainable carbon sources, noble metal catalysts, and harsh conditions. Herein, we report the first work to synthesize cyclohexanone oxime through electroreduction of phenol and hydroxylamine. The Faradaic efficiency reached 69.1% over Cu catalyst, accompanied by a corresponding cyclohexanone oxime formation rate of 82.0 g h-1 gcat-1. In addition, the conversion of phenol was up to 97.5%. In situ characterizations, control experiments, and theoretical calculations suggested the importance of balanced activation of water, phenol, and hydroxylamine substrates on the optimal metallic Cu catalyst for achieving high-performance cyclohexanone oxime synthesis. Besides, a tandem catalytic route for the upgrading of lignin to caprolactam has been successfully developed through the integration of thermal catalysis, electrocatalysis, and Beckmann rearrangement, which achieved the synthesis of 0.40 g of caprolactam from 4.0 g of lignin raw material.

19.
Rev Cardiovasc Med ; 23(9): 315, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39077690

RESUMEN

Background: Several prospective controlled trials to date have assessed the safety and efficacy of paclitaxel-coated balloon angioplasty (PCBA) versus uncoated balloon angioplasty (UCBA) for femoropopliteal (FP) in-stent restenosis (ISR). Therefore, this meta-analysis of prospective controlled trials aimed to summarize the results of these trials and present reliable conclusions. Methods: We systematically searched the PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials.gov, and CNKI databases for prospective randomized controlled trials (published between January 1, 2008, and July 31, 2021; no language restrictions) comparing PCBA with UCBA in the management of FP ISR. The main endpoints were recurrent restenosis, primary patency, freedom from target lesion revascularization (TLR), clinical improvement, ankle-brachial index (ABI), and major adverse events (MAEs). We assessed the pooled data using a fixed effects model. Results: Of the 206 identified studies, seven were eligible and included in our analysis (N = 593 participants). Compared with UCBA, PCBA yielded a reduction in recurrent restenosis (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.13-0.38), a better primary patency (OR, 3.59; 95% CI, 1.72-7.47), an improved likelihood of freedom from TLR (OR, 2.70; 95% CI, 1.36-5.35), greater clinical improvement (OR, 2.38; 95% CI, 1.50-3.79), and a similar mean difference in ABI (0.02; 95% CI, -0.11-0.14) and OR in MAEs (0.71; 95% CI, 0.24-2.14). Conclusions: PCBA as a treatment strategy can achieve better short-term outcomes of FP ISR management, including potent recurrent restenosis-lowering and symptom-improving capacity without increased MAEs. Therefore, it is a promising therapeutic strategy for patients with FP ISR. Systematic Review Registration: This work was registered in PROSPERO, the international prospective register of systematic reviews (number: CRD42021261574).

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA