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1.
Int J Neurosci ; : 1-19, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38758136

RESUMEN

OBJECTIVE: The aim of this study was to investigate the effects of virtual reality training combined with traditional Chinese medicine health preservation therapy on cognitive function, neurological function, and physical function of stroke patients. METHODS: The patients were randomly divided into an experimental group (receiving virtual reality training combined with traditional Chinese medicine health preservation therapy) and a control group (receiving conventional rehabilitation treatment combined with traditional Chinese medicine health preservation therapy). A series of cognitive, neurological, and physical function assessments were conducted to collect and analyze data from both groups before treatment, after treatment, and during follow-up. The application of traditional Chinese medicine health preservation concepts was also explored. RESULTS: After treatment, the experimental group had significantly higher scores in the Mini-Mental State Examination (MMSE) compared to the control group. The overall effective rate of neurological function in the experimental group was higher than that in the control group. The Fugl-Meyer Assessment (FMA) scores for upper limb function in the experimental group were significantly higher than those in the control group. The degree of improvement in the Modified Barthel Index scores after treatment was significantly better in the experimental group compared to the control group (all P < 0.05). CONCLUSION: The results of this study demonstrate that virtual reality training combined with traditional Chinese medicine health preservation therapy significantly improves cognitive function, neurological function, and physical function in stroke patients. This approach provides new insights and methods for stroke rehabilitation therapy and is worthy of promotion.

2.
Chemistry ; 29(25): e202203765, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-36752729

RESUMEN

Photocatalytic hydrogen peroxide (H2 O2 ) production on BiVO4 photocatalysts using water and oxygen as raw materials is a green and sustainable process. However, the photocatalytic efficiency of pristine BiVO4 is limited by severe charge recombination. In this work, rare earth element Yttrium (Y) doped BiVO4 photocatalysts were fabricated by the hydrothermal method. In the photocatalytic H2 O2 production experiment, the optimized Y-doped BiVO4 photocatalyst produced 114 µmol g-1 h-1 of H2 O2 under simulated sunlight (AM1.5) irradiation, which is four times higher than production activity of pure BiVO4 (26 µmol g-1 h-1 ). Density functional theory (DFT) calculation revealed that Y doping can enhance oxygen adsorption on the BiVO4 photocatalyst surface. Mechanistic investigations suggest that the doping process induces the in situ formation of monoclinic/tetragonal BiVO4 heterojunction, which further promotes the photogenerated carriers separation efficiency.

3.
Chemistry ; 29(39): e202300999, 2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37114518

RESUMEN

Severe poisonousness and prolonged instability existing in organic-inorganic lead-based perovskite are two matters seriously hindering its potential future application in photocatalysis. Therefore, it is particularly important to explore ecology-friendly, air-stable and highly active metal-halide perovskites. Herein, a new and stable lead-free perovskite Cs2 SnBr6 decorated with reduced graphene oxide (rGO), is synthesized and employed in the photocatalytic organic conversion. The as-prepared Cs2 SnBr6 is ultrastable, exhibiting no clear changes after being placed in the air for six months. The Cs2 SnBr6 /rGO composite shows excellent photocatalytic activity in photo-driven-oxidation of 5-hydroxymethylfurfural (HMF) to high value enclosed 2,5-diformylfuran (DFF), achieving>99.5 % conversion of HMF and 88 % DFF selectivity in the presence of green oxidant O2 . Comprehensive characterizations disclose a multistep reaction mechanism, demonstrating that the molecular oxygen, photogenerated carriers, ⋅O2 - and 1 O2 altogether synergistically participate in the effective photo-driven conversion of HMF to DFF. This work expands the material gallery towards selective organic conversion and environmentally friendly perovskite options for photocatalytic application.

4.
Langmuir ; 39(24): 8503-8515, 2023 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-37284830

RESUMEN

Catalytic oxidation has been extensively studied as a promising technology for the removal of toluene from industrial waste gases and indoor air. However, the debate regarding the oxidation mechanism is far from resolved. CexMn1-xO2 catalysts with different mixing ratios are prepared by the sol-gel method and found to exhibit better catalytic activities for toluene oxidation than a single oxide. Characterizations and theoretical calculations reveal that the doped Mn increases the number of oxygen vacancies and the ability of oxygen vacancies to activate aromatic rings, which promotes the rate-determining step of toluene oxidation, i.e., ring-opening reactions. The oxidation products detected by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and Vocus proton transfer reaction mass spectrometry (Vocus-PTR-MS) show that the doped Mn significantly improves the ring-opening efficiency and subsequently yields more short-chain products, such as pyruvic acid and acetic acid. A comprehensive oxidation pathway of toluene is refined in this work.

5.
J Environ Sci (China) ; 134: 77-85, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37673535

RESUMEN

Mineralization of benzene, toluene, and xylene (BTX) with high efficiency at room temperature is still a challenge for the purification of indoor air. In this work, a foam Ti/Sb-SnO2/ß-PbO2 anode catalyst was prepared for electrocatalytically oxidizing gaseous toluene in an all-solid cell at ambient temperature. The complex Ti/Sb-SnO2/ß-PbO2 anode, which was prepared by sequentially deposing Sb-SnO2 and ß-PbO2 on a foam Ti substrate, shows high electrocatalytic oxidation efficiency of toluene (80%) at 7 hr of reaction and high CO2 selectivity (94.9%) under an optimized condition, i.e., a cell voltage of 2.0 V, relative humidity of 60% and a flow rate of 100 mL/min. The better catalytic performance can be ascribed to the high production rate of ⋅OH radicals from discharging adsorbed water and the inhibition of oxygen evolution on the surface of foam Ti/Sb-SnO2/ß-PbO2 anode when compared with the foam Ti/Sb-SnO2 anode. Our results demonstrate that prepared complex electrodes can be potentially used for electrocatalytic removal of gaseous toluene at room temperature with a good performance.


Asunto(s)
Gases , Titanio , Oxidación-Reducción , Electrodos , Tolueno
6.
Angew Chem Int Ed Engl ; 62(36): e202302919, 2023 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-37389483

RESUMEN

Photoconversion of CO2 and H2 O into ethanol is an ideal strategy to achieve carbon neutrality. However, the production of ethanol with high activity and selectivity is challenging owing to the less efficient reduction half-reaction involving multi-step proton-coupled electron transfer (PCET), a slow C-C coupling process, and sluggish water oxidation half-reaction. Herein, a two-dimensional/two-dimensional (2D/2D) S-scheme heterojunction consisting of black phosphorus and Bi2 WO6 (BP/BWO) was constructed for photocatalytic CO2 reduction coupling with benzylamine (BA) oxidation. The as-prepared BP/BWO catalyst exhibits a superior photocatalytic performance toward CO2 reduction, with a yield of 61.3 µmol g-1 h-1 for ethanol (selectivity of 91 %).In situ spectroscopic studies and theoretical calculations reveal that S-scheme heterojunction can effectively promote photogenerated carrier separation via the Bi-O-P bridge to accelerate the PCET process. Meanwhile, electron-rich BP acts as the active site and plays a vital role in the process of C-C coupling. In addition, the substitution of BA oxidation for H2 O oxidation can further enhance the photocatalytic performance of CO2 reduction to C2 H5 OH. This work opens a new horizon for exploring novel heterogeneous photocatalysts in CO2 photoconversion to C2 H5 OH based on cooperative photoredox systems.

7.
Angew Chem Int Ed Engl ; 61(41): e202209446, 2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-35989227

RESUMEN

Selective CO2 photoreduction to hydrocarbon fuels such as CH4 is promising and sustainable for carbon-neutral future. However, lack of proper binding strengths with reaction intermediates makes it still a challenge for photocatalytic CO2 methanation with both high activity and selectivity. Here, low-coordination single Au atoms (Au1 -S2 ) on ultrathin ZnIn2 S4 nanosheets was synthesized by a complex-exchange route, enabling exceptional photocatalytic CO2 reduction performance. Under visible light irradiation, Au1 /ZnIn2 S4 catalyst exhibits a CH4 yield of 275 µmol g-1 h-1 with a selectivity as high as 77 %. As revealed by detailed characterizations and density functional theory calculations, Au1 /ZnIn2 S4 with Au1 -S2 structure not only display fast carrier transfer to underpin its superior activity, but also greatly reduce the energy barrier for protonation of *CO and stabilize the *CH3 intermediate, thereby leading to the selective CH4 generation from CO2 photoreduction.

8.
J Virol ; 91(12)2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28381569

RESUMEN

Bats are natural reservoirs for many pathogenic viruses, and increasing evidence supports the notion that bats can also harbor group A rotaviruses (RVAs), important causative agents of diarrhea in children and young animals. Currently, 8 RVA strains possessing completely novel genotype constellations or genotypes possibly originating from other mammals have been identified from African and Chinese bats. However, all the data were mainly based on detection of RVA RNA, present only during acute infections, which does not permit assessment of the true exposure of a bat population to RVA. To systematically investigate the genetic diversity of RVAs, 547 bat anal swabs or gut samples along with 448 bat sera were collected from five South Chinese provinces. Specific reverse transcription-PCR (RT-PCR) screening found four RVA strains. Strain GLRL1 possessed a completely novel genotype constellation, whereas the other three possessed a constellation consistent with the MSLH14-like genotype, a newly characterized group of viruses widely prevalent in Chinese insectivorous bats. Among the latter, strain LZHP2 provided strong evidence of cross-species transmission of RVAs from bats to humans, whereas strains YSSK5 and BSTM70 were likely reassortants between typical MSLH14-like RVAs and human RVAs. RVA-specific antibodies were detected in 10.7% (48/448) of bat sera by an indirect immunofluorescence assay (IIFA). Bats in Guangxi and Yunnan had a higher RVA-specific antibody prevalence than those from Fujian and Zhejiang provinces. These observations provide evidence for cross-species transmission of MSLH14-like bat RVAs to humans, highlighting the impact of bats as reservoirs of RVAs on public health.IMPORTANCE Bat viruses, such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), Ebola, Hendra, and Nipah viruses, are important pathogens causing outbreaks of severe emerging infectious diseases. However, little is known about bat viruses capable of causing gastroenteritis in humans, even though 8 group A viruses (RVAs) have been identified from bats so far. In this study, another 4 RVA strains were identified, with one providing strong evidence for zoonotic transmission from bats to humans. Serological investigation has also indicated that RVA infection in bats is far more prevalent than expected based on the detection of viral RNA.


Asunto(s)
Quirópteros/virología , Reservorios de Enfermedades/virología , Variación Genética , Virus Reordenados , Infecciones por Rotavirus/veterinaria , Rotavirus/genética , Canal Anal/virología , Animales , Anticuerpos Antivirales/sangre , Preescolar , China , Genoma Viral , Genotipo , Humanos , Intestinos/virología , Filogenia , ARN Viral/genética , Rotavirus/clasificación , Rotavirus/inmunología , Rotavirus/aislamiento & purificación , Infecciones por Rotavirus/inmunología , Infecciones por Rotavirus/transmisión , Infecciones por Rotavirus/virología , Zoonosis
9.
Environ Sci Technol ; 52(12): 6834-6841, 2018 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-29775300

RESUMEN

Secondary organic aerosol (SOA) is an important component of atmospheric fine particles (PM2.5), while the key factors controlling SOA formation in ambient air remain poorly understood. In this work, the SOA formation in Beijing urban ambient air was investigated using an oxidation flow reactor (OFR) with high concentrations of OH radicals. The SOA formation potential increased significantly with the increase of ambient PM2.5 concentration during the observation. The optimum ambient exposure time, which is the aging time equivalent to atmospheric oxidation (with similar OH exposure) associated with the peak SOA formation, varied between 2 and 4 days in this study. The OA enhancement in this study was much higher than that of developed countries under different environmental conditions. The higher OA enhancement is probably due to the higher concentrations of volatile organic compounds (VOCs) in the urban air of Beijing. This might also have occurred because fragmentation did not dominate in the oxidation of OA, and did not result in negative OA enhancement on highly polluted days compared to relatively clean days with similar exposure time. These results suggested that under typical ambient conditions, high concentrations of VOC precursors might contribute to sustained organic aerosol growth and long duration haze events in Beijing.


Asunto(s)
Contaminantes Atmosféricos , Compuestos Orgánicos Volátiles , Aerosoles , Beijing
10.
Phys Chem Chem Phys ; 17(29): 19424-31, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-26145684

RESUMEN

In order to obtain reliable kinetic parameters, it is required to measure the reaction kinetics of important heterogeneous reactions at ambient relative humidity (RH). In this study, the uptake coefficients and HONO yields for the heterogeneous reaction of NO2 on kaolin and hematite were measured at RH from 7% to 74% and at ambient pressure in the dark using a coated-wall flow tube reactor. The initial true uptake coefficient (γt,ini) of NO2 at RH 7% was measured to be (1.44 ± 0.10) × 10(-7) and (1.58 ± 0.13) × 10(-6) on kaolin and hematite, respectively, while it decreased notably on both minerals, accompanied by an increase of HONO yields, as RH increased. The average γt,ini at 32-74% RH was (4.42 ± 1.17) × 10(-8) and (2.83 ± 0.84) × 10(-7) on kaolin and hematite, respectively. The corresponding mean HONO yield was (36.0 ± 16.1)% and (75.9 ± 3.32)%, respectively.

11.
J Virol ; 87(22): 12357-66, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24027312

RESUMEN

Bats are considered important animal reservoirs for many viruses pathogenic to humans. An approach based on viral metagenomics was used to study gut specimens from 78 insectivorous bats in Yunnan Province, China. Seventy-four reads were found to be related to group A rotavirus (RVA). Further reverse transcription-PCR screening and viral isolation on cell cultures confirmed the presence of a novel RVA strain, named RVA/Bat-tc/MSLH14/2012/G3P[3], in 1 (6%) of 16 lesser horseshoe bats. Full genomic sequencing analyses showed that MSLH14 possessed the genotype constellation G3-P[3]-I8-R3-C3-M3-A9-N3-T3-E3-H6, which is akin to human and animal rotaviruses believed to be of feline/canine origin. Phylogenetic analysis indicated that VP7 was most closely related to bovine RVA strains from India, whereas VP4 was most closely related to an unusual human RVA strain, CMH222, with animal characteristics isolated in Thailand. The remaining gene segments were only distantly related to a range of animal RVA strains, most of which are believed to be related to feline/canine RVAs. Experimental infection showed that bat RVA strain MSLH14 was highly pathogenic to suckling mice, causing 100% mortality when they were inoculated orally with a titer as low as 5 × 10² 50% tissue culture infective doses. As this virus is not closely related to any known RVA strain, it is tempting to speculate that it is a true bat RVA strain rather than a virus transmitted between species. However, further screening of bat populations, preferably juvenile animals, will be crucial in determining whether or not this virus is widely distributed in the bat population.


Asunto(s)
Genoma Viral , ARN Viral/genética , Infecciones por Rotavirus/virología , Rotavirus/aislamiento & purificación , Proteínas Virales/genética , Animales , Teorema de Bayes , Evolución Biológica , Gatos , Bovinos , China/epidemiología , Quirópteros , Femenino , Humanos , Ratones , Filogenia , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rotavirus/clasificación , Rotavirus/genética , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/genética , Análisis de Secuencia de ADN
12.
J Clin Ethics ; 25(2): 135-47, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24972064

RESUMEN

BACKGROUND: Medical professionalism has been developing in the Peoples' Republic of China as one way to better address perennial and new challenges in healthcare in an ever-changing society. Among many recent developments in this area is promotion by the national Chinese Medical Doctor Association of the principles and values contained in the international document, "Medical Professionalism in the New Millennium: A Physician Charter." OBJECTIVE: To discover Chinese physicians' attitudes toward and understanding of medical professionalism. METHODOLOGY: The authors distributed a self-reporting questionnaire that included 34 statements and four case scenarios concerning the general principles of medical professionalism: the primacy of patients' welfare, respect for patients' autonomy, promotion of social justice, and professional self-regulation. The questionnaire included controversial issues such as the role of the family in decision making and reporting medical errors. A total of 2,966 practicing physicians, randomly selected from the Chinese Medical Association database, were surveyed, and 1,198 valid questionnaires were returned. Our sample covered 23 provinces and 51 cities throughout the Peoples' Republic of China. RESULTS: More than 80 percent of the physicians who responded agreed that the physician-patient relationship should be a relationship of trust founded on professional altruism, and that informed consent is necessary. More than 95 percent agreed that physicians should promote professional self-regulation as well as social justice. More than half agreed with the principle of the primacy of patients' welfare (62.8 percent), and that physicians have a responsibility to report medical errors and incompetent colleagues (51.0 percent). In certain cases, a great majority of Chinese physicians favored familism and paternalism. LIMITATIONS: The study does not include data on how Chinese physicians practice medical professionalism, or the perspectives of physicians working in smaller cities and in rural areas. CONCLUSIONS: Based on responses to the survey, Chinese physicians strongly support the majority of the fundamental principles and responsibilities of medical professionalism, including dedication, altruism, social justice, self-regulation, and informed consent. However, their support for the primacy of patients' welfare as a general principle, and the physician's responsibility to report medical errors and incompetent colleagues, is relatively low. To help advance medical professionalism in the People's Republic of China, professional development programs and medical ethics education should not only emphasize the general principles involved, but also formulate guidelines on how these principles can be carried out in practice.


Asunto(s)
Pueblo Asiatico/estadística & datos numéricos , Actitud del Personal de Salud , Comprensión , Relaciones Médico-Paciente/ética , Médicos/ética , Médicos/estadística & datos numéricos , Adulto , Altruismo , Discusiones Bioéticas , China/epidemiología , Características Culturales , Ética Médica , Femenino , Encuestas de Atención de la Salud , Humanos , Consentimiento Informado , Masculino , Persona de Mediana Edad , Paternalismo , Autonomía Personal , Médicos/psicología , Justicia Social , Estados Unidos
13.
J Environ Sci (China) ; 26(5): 962-9, 2014 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25079626

RESUMEN

The occurrence of antibiotics in the environment has recently raised serious concerns regarding their potential threat to human health and aquatic ecosystem. A new magnetic nanocomposite, Fe3O4@C (Fe3O4 coated with carbon), was synthesized, characterized, and then applied to remove five commonly-used sulfonamides (SAs) from water. Due to its combinational merits of the outer functionalized carbon shell and the inner magnetite core, Fe3O4@C exhibited a high adsorption affinity for selected SAs and a fast magnetic separability. The adsorption kinetics of SAs on Fe3O4@C could be expressed by the pseudo second-order model. The adsorption isotherms were fitted well with the Dual-mode model, revealing that the adsorption process consisted of an initial partitioning stage and a subsequent hole-filling stage. Solution pH exerted a strong impact on the adsorption process with the maximum removal efficiencies (74% to 96%) obtained at pH 4.8 for all selected SAs. Electrostatic force and hydrogen bonding were two major driving forces for adsorption, and electron-donor-acceptor interactions may also make a certain contribution. Because the synthesized Fe3O4@C showed comprehensive advantages of high adsorptivity, fast magnetic separability, and prominent reusability, it has potential applications in water treatment.


Asunto(s)
Antibacterianos/química , Carbono/química , Nanocompuestos/química , Sulfonamidas/química , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Magnetismo , Modelos Moleculares , Estructura Molecular , Temperatura , Agua/química
14.
Lancet Diabetes Endocrinol ; 12(3): 184-195, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38330988

RESUMEN

BACKGROUND: Data on the benefits of the once weekly GLP-1 receptor agonist semaglutide 2·4 mg for weight management in people from east Asia are insufficient. The objective of this study was to determine the efficacy and safety of once weekly semaglutide 2·4 mg versus placebo for weight management in a predominantly east Asian adult population. METHODS: This randomised phase 3a, double-blind multicentre controlled trial (STEP 7) recruited participants from 23 hospitals and trial centres in China, Hong Kong, Brazil, and South Korea. Adults with overweight or obesity, with or without type 2 diabetes, were randomly assigned (2:1) to receive a subcutaneous injection of either semaglutide 2·4 mg or placebo once a week for 44 weeks, plus a diet and physical activity intervention. Randomisation was done in blocks of six with an interactive web response system and was stratified by diagnosis of type 2 diabetes. Participants, investigators, and the trial sponsor were masked to treatment allocation until after database lock. Primary endpoints were percentage change in mean bodyweight and proportion of participants having reached a weight reduction of at least 5% of bodyweight from baseline to week 44. Safety was assessed in all participants who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, NCT04251156, and is now complete. FINDINGS: From Dec 8, 2020, to Aug 23, 2022, 448 participants were screened, of whom 375 were randomly assigned to either the semaglutide 2·4 mg group (n=249) or the placebo group (n=126). Estimated mean percentage change in bodyweight from baseline to week 44 was -12·1% (SE 0·5) with semaglutide 2·4 mg versus -3·6% (0·7) with placebo (estimated treatment difference -8·5 percentage points [95% CI -10·2 to -6·8]; p<0·0001). At week 44, the proportion of participants who lost 5% or more of their bodyweight was higher in the semaglutide 2·4 mg group than in the placebo group (203/238 [85%] vs 36/116 [31%]); odds ratio 13·1 (95% CI 7·4-23·1; p<0·0001). Adverse events were reported by 231 (93%) of 249 participants in the semaglutide 2·4 mg group and 108 (86%) of 126 participants in the placebo group, the most common of which were gastrointestinal disorders (168/249, 67% vs 45/126, 36%). INTERPRETATION: The results of this study support the use of semaglutide 2·4 mg for weight management in people of east Asian ethnicity with overweight or obesity and with or without type 2 diabetes. FUNDING: Novo Nordisk. TRANSLATIONS: For the Mandarin, Portuguese and South Korean translations of the abstract see Supplementary Materials section.


Asunto(s)
Péptidos Similares al Glucagón , Obesidad , Sobrepeso , Adulto , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Método Doble Ciego , Pueblos del Este de Asia , Péptidos Similares al Glucagón/uso terapéutico , Hipoglucemiantes/uso terapéutico , Obesidad/tratamiento farmacológico , Sobrepeso/tratamiento farmacológico , Resultado del Tratamiento
15.
Environ Int ; 187: 108724, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38735076

RESUMEN

The mass concentration of atmospheric particulate matter (PM) has been continuously decreasing in the Beijing-Tianjin-Hebei region. However, health endpoints do not exhibit a linear correlation with PM mass concentrations. Thus, it is urgent to clarify the prior toxicological components of PM to further improve air quality. In this study, we analyzed the long-term oxidative potential (OP) of water-soluble PM2.5, which is generally considered more effective in assessing hazardous exposure to PM in Beijing from 2018 to 2022 based on the dithiothreitol assay and identified the crucial drivers of the OP of PM2.5 based on online monitoring of air pollutants, receptor model, and random forest (RF) model. Our results indicate that dust, traffic, and biomass combustion are the main sources of the OP of PM2.5 in Beijing. The complex interactions of dust particles, black carbon, and gaseous pollutants (nitrogen dioxide and sulfur dioxide) are the main factors driving the OP evolution, in particular, leading to the abnormal rise of OP in Beijing in 2022. Our data shows that a higher OP is observed in winter and spring compared to summer and autumn. The diurnal variation of the OP is characterized by a declining trend from 0:00 to 14:00 and an increasing trend from 14:00 to 23:00. The spatial variation in OP of PM2.5 was observed as the OP in Beijing is lower than that in Shijiazhuang, while it is higher than that in Zhenjiang and Haikou, which is primarily influenced by the distribution of black carbon. Our results are of significance in identifying the key drivers influencing the OP of PM2.5 and provide new insights for advancing air quality improvement efforts with a focus on safeguarding human health in Beijing.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Monitoreo del Ambiente , Material Particulado , Material Particulado/análisis , Beijing , Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Oxidación-Reducción , Mejoramiento de la Calidad , Estaciones del Año
16.
Adv Mater ; 35(45): e2304133, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37474109

RESUMEN

The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) is a promising method for the efficient production of biomass-derived high-value-added chemicals. However, its practical application is limited by: 1) the low activity and selectivity caused by the competitive adsorption of HMF and OH- and 2) the low operational stability caused by the uncontrollable reconstruction of the catalyst. To overcome these limitations, a series of Ni3 S2 /NiOx -n catalysts with controllable compositions and well-defined structures are synthesized using a novel in situ controlled surface reconstruction strategy. The adsorption behavior of HMF and OH- can be continuously adjusted by varying the ratio of NiOx to Ni3 S2 on the catalysts surface, as indicated by in situ characterizations, contact angle analysis, and theoretical simulations. Owing to the balanced competitive adsorption of HMF and OH- , the optimized Ni3 S2 /NiOx -15 catalyst exhibited remarkable HMF electrocatalytic oxidation performance, with the current density reaching 366 mA cm-2 at 1.5 VRHE and the Faradaic efficiency of the product, 2,5-furanedicarboxylic acid, reaching 98%. Moreover, Ni3 S2 /NiOx -15 exhibits excellent durability, with its activity and structure remaining stable for over 100 h of operation. This study provides a new route for the design and construction of catalysts for value-added biomass conversion and offers new insights into enhancing catalytic performance by balancing competitive adsorption.

17.
NPJ Clim Atmos Sci ; 6(1): 37, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37214635

RESUMEN

Wintertime meteorological conditions are usually unfavorable for ozone (O3) formation due to weak solar irradiation and low temperature. Here, we observed a prominent wintertime O3 pollution event in Shijiazhuang (SJZ) during the Chinese New Year (CNY) in 2021. Meteorological results found that the sudden change in the air pressure field, leading to the wind changing from northwest before CNY to southwest during CNY, promotes the accumulation of air pollutants from southwest neighbor areas of SJZ and greatly inhibits the diffusion and dilution of local pollutants. The photochemical regime of O3 formation is limited by volatile organic compounds (VOCs), suggesting that VOCs play an important role in O3 formation. With the developed O3 formation path tracing (OFPT) approach for O3 source apportionment, it has been found that highly reactive species, such as ethene, propene, toluene, and xylene, are key contributors to O3 production, resulting in the mean O3 production rate (PO3) during CNY being 3.7 times higher than that before and after CNY. Industrial combustion has been identified as the largest source of the PO3 (2.6 ± 2.2 ppbv h-1), with the biggest increment (4.8 times) during CNY compared to the periods before and after CNY. Strict control measures in the industry should be implemented for O3 pollution control in SJZ. Our results also demonstrate that the OFPT approach, which accounts for the dynamic variations of atmospheric composition and meteorological conditions, is effective for O3 source apportionment and can also well capture the O3 production capacity of different sources compared with the maximum incremental reactivity (MIR) method.

18.
ChemSusChem ; 16(19): e202300666, 2023 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-37505451

RESUMEN

In this work, α-Fe2 O3 photoanode consisted of (110)-oriented α-Fe2 O3 single crystals were synthesized by a facile hydrothermal method. By using particular additive (C4 MimBF4 ) and regulation of hydrothermal reaction time, the Fe-25 consisted of a single-layer of highly crystalline (110)-oriented crystals with fewer grain boundaries, which was vertically grown on the substrate. As a result, the charge separation efficiency and photoelectrochemical (PEC) performance of Fe-25A (Fe-25 after dehydration treatment) have been greatly improved. Fe-25A yields a photocurrent of 1.34 mA cm-2 (1.23 V vs RHE) and an incident photon-to-current conversion efficiency (IPCE) of 31.95 % (380 nm). With the assistance of cobalt-phosphate water oxidation catalyst (Co-Pi), the PEC performance could be further improved by enhancing the holes transfer at electrode/electrolyte interface and inhibiting surface recombination. Fe-25A/Co-Pi yields a photocurrent of 2.67 mA cm-2 (1.23 V vs RHE) and IPCE value of 50.8 % (380 nm), which is 3.67 times and 2.39 times as that of Fe-2A/Co-Pi. Our work provides a simple method to fabricate highly efficient Fe2 O3 photoanodes consist of characteristic (110)-oriented single crystals with high crystallinity and high quality interface contact to enhance charge separation efficiencies.

19.
Huan Jing Ke Xue ; 44(12): 6463-6473, 2023 Dec 08.
Artículo en Zh | MEDLINE | ID: mdl-38098375

RESUMEN

To explore the characteristics and sources of PM2.5 pollution in winter of Handan City in the past five years, PM2.5 samples were collected in winter of 2016 to 2020, and eight types of water-soluble inorganic ions were analyzed. The principal component analysis(PCA) model was used to analyze the types of pollution sources, and the backward trajectory and potential source contribution factor(PSCF) were used to simulate the transport trajectory and pollution sources. The results showed that the PM2.5 concentration in winter of 2018 was the highest, increasing by 60.44%, 25.46%, 91.43%, and 21.53% compared with that in 2016, 2017, 2019, and 2020, respectively. In the winter of 2020, the concentration of water-soluble inorganic ions(WSIIs) decreased by 18.86% compared with that in 2016, and WSIIs/PM2.5 decreased to 26.69%. The PM2.5 concentration(110.20-209.65 µg·m-3) at night was higher than that in the daytime(95.21-193.00 µg·m-3). The concentration of NO3- and NH4+ increased more at night. On the contrary, the concentration and proportion of Cl-decreased annually. In the winter of 2020, the daytime concentrations of K+, Ca2+, Na+, and Mg2+ decreased by 69.72%, 97.10%, 90.91%, and 74.51% compared with that of 2018, and the night concentrations decreased by 66.67%, 95.38%, 91.67%, and 77.78%, respectively. In 2020, the concentrations of NO3-, SO42-, and NH4+ on polluted days were 4.90, 5.80, and 5.20 times those on non-polluted days, with the largest increase in five years. PCA results showed that the main sources of pollution were secondary sources, coal sources, biomass combustion sources, and road and building dust. The backward trajectory and PSCF analysis results showed that pollution transport continued to exist between south-central Mongolia and central Inner Mongolia in winter and was influenced by the transport between northern Henan and Handan and central Hebei and Handan in winter of 2016 and 2017, whereas the latter had a greater impact in winter of 2018-2020.

20.
Zhong Xi Yi Jie He Xue Bao ; 10(12): 1371-4, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23257128

RESUMEN

Multifactor designs that are able to examine the interactions include factorial design, factorial design with a block factor, repeated measurement design; orthogonal design, split-block design, etc. Among all the above design types that are able to examine the interactions, the factorial design is the most commonly used. It is also called the full-factor experimental design, which means that the levels of all the experimental factors involved in the research are completely combined, and k independent repeated experiments are conducted under each experimental condition. The factorial design with a block factor can also examine the influence of a block factor formed by one or more important non experimental factors based on the factorial design. This article introduces the factorial design and the factorial design with a block factor by examples.


Asunto(s)
Análisis Factorial , Proyectos de Investigación
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