Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 314
Filtrar
1.
Chemosphere ; 362: 142565, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38871187

RESUMO

Compared to the particle-gas partition coefficients (KPG), the rain-gas (KRG) and snow-gas (KSG) partition coefficients are also essential in studying the environmental behavior and fate of chemicals in the atmosphere. While the temperature dependence for the KPG have been extensively studied, the study for KRG and KSG are still lacking. Adsorption coefficients between water surface-air (KIA) and snow surface-air (KJA), as well as partition coefficients between water-air (KWA) and octanol-air (KOA) are vital in calculating KRG and KSG. These four basic adsorption and partition coefficients are also temperature-dependent, given by the well-known two-parameters Antoine equation logKXY = AXY + BXY/T, where KXY is the adsorption or partition coefficients, AXY and BXY are Antoine parameters (XY stand for IA, JA, WA, and OA), and T is the temperature in Kelvin. In this study, the parameters AXY and BXY are calculated for 943 chemicals, and logKXY can be estimated at any ambient temperature for these chemicals using these Antoine parameters. The results are evaluated by comparing these data with published experimental and modeled data, and the results show reasonable accuracy. Based on these coefficients, temperature-dependence of logKRG and logKSG is studied. It is found that both logKRG and logKSG are linearly related to 1/T, and Antoine parameters for logKRG and logKSG are also estimated. Distributions of the 943 chemicals in the atmospheric phases (gas, particle, and rain/snow), are illustrated in a Chemical Space Map. The findings reveal that, at environmental temperatures and precipitation days, the dominant state for the majority of chemicals is the gaseous phase. All the AXY and BXY values for logKSG, logKRG, and basic adsorption and partition coefficients, both modeled by this study and collected from published work, are systematically organized into an accessible dataset for public utilization.

2.
Shock ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38888575

RESUMO

BACKGROUND: Despite rapid advances in treatment, sepsis currently remains a major public health challenge worldwide. Over the past several years, there has been an increase in the clinical incidence of sepsis, as well as an increase in hospitalization rates, which bear the majority of the economic burden associated with sepsis. Sepsis is a public health burden due to the high fatality rates and accompanying morbidity. However, the sepsis-related mortality rates have fallen steadily over the years. One of the most common organs to fail in patients with sepsis is the kidney, and acute kidney injury(AKI) is associated with high mortality rates. This study's primary goal was to assess the impact of AKI on the evolution and outcome of hospitalization of patients with sepsis. METHODS: Adults (≥18 years) hospitalized for sepsis in the United States between 2010 and 2019 were retrospectively analysed using the nationally representative NIS database.Sepsis and acute kidney injury were defined using the codes of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). RESULTS: Of the 4,258,360 outcomes, 3,946,048 met the inclusion criteria. The prevalence of AKI among sepsis inpatients increased from 39.10% in 2010 to 41% in 2019, but the impact of AKI on mortality declined over time, with in-hospital mortality from AKI among sepsis inpatients decreasing from 26.30% in 2010 to 16.30% in 2019. Hospitalizations linked to AKI were substantially more likely to involve infection sites such as the urinary tract, gastrointestinal tract, and endocarditis. Numerous pathogenic floras, including Escherichia coli [E. coli], Staphylococcus aureus, Streptococcal, Enterococcus, and Pseudomonas, had greater rates among sepsis-related contacts with AKI. Furthermore, compared to hospitalization without comorbid AKI, the median total hospital charges and length of stay days for sepsis hospitalization with comorbid AKI were greater. CONCLUSIONS: With time, patients with sepsis have a higher frequency of AKI and a corresponding decline in mortality.

3.
J Hazard Mater ; 473: 134676, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38788579

RESUMO

Medium-chain fatty acids (MCFAs) production from waste activated sludge (WAS) by chain extension (CE) is a promising technology. However, the effects and mechanisms of CE process on the fate of antibiotic resistance genes (ARGs) remain unclear. In this study, the results showed that the removal efficiency of ARGs was 81.15 % in CE process, suggesting its efficacy in reducing environmental risks. Further, the observed decrease in mobile genetic elements (MGEs) indicated that CE process restricted the horizontal gene transfer (HGT). Complementing this, the increase in soluble organic matters and extracellular 16 S rDNA confirmed that MCFAs production caused bacterial damage. Decreased intracellular ARGs and increased extracellular ARGs further revealed that MCFAs production impaired ARGs hosts, thereby limiting the vertical gene transfer (VGT) of ARGs. Shift of microbial community combined with co-occurrence network analysis demonstrated that functional bacteria without host potential for ARGs were enriched, but potential ARGs and MGEs hosts decreased, showing the role of functional bacterial phylogeny and selection pressure of MCFAs in reducing ARGs. Finally, partial least squares path model was used to systematic verify the mechanism of ARGs removal in CE process, which was attributed to the inhibition of ARGs transmission (HGT and VGT) and shift of microbial community.


Assuntos
Bactérias , Resistência Microbiana a Medicamentos , Ácidos Graxos , Esgotos , Esgotos/microbiologia , Ácidos Graxos/metabolismo , Resistência Microbiana a Medicamentos/genética , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Microbiota/efeitos dos fármacos , Transferência Genética Horizontal , Genes Bacterianos , Eliminação de Resíduos Líquidos/métodos , Antibacterianos/farmacologia
4.
J Environ Manage ; 359: 120979, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692033

RESUMO

If pharmaceutical wastewater is not managed effectively, the presence of residual antibiotics will result in significant environmental contamination. In addition, inadequate utilization of agricultural waste represents a squandering of resources. The objective of this research was to assess the efficacy of iron-doped biochar (Fe-BC) derived from peanut shells in degrading high concentrations of Tetracycline (TC) wastewater through activated peroxymonosulfate. Fe-BC demonstrated significant efficacy, achieving a removal efficiency of 87.5% for TC within 60 min without the need to adjust the initial pH (20 mg/L TC, 2 mM PMS, 0.5 g/L catalyst). The degradation mechanism of TC in this system involved a dual action, namely Reactive Oxygen Species (ROS) and electron transfer. The primary active sites were the Fe species, which facilitated the generation of SO4•-, •OH, O2•-, and 1O2. The presence of Fe species and the C=C structure in the Fe-BC catalyst support the electron transfer. Degradation pathways were elucidated through the identification of intermediate products and calculation of the Fukui index. The Toxicity Estimator Software Tool (T.E.S.T.) suggested that the intermediates exhibited lower levels of toxicity. Furthermore, the system exhibited exceptional capabilities in real water and circulation experiments, offering significant economic advantages. This investigation provides an efficient strategy for resource recycling and the treatment of high-concentration antibiotic wastewater.


Assuntos
Carvão Vegetal , Ferro , Espécies Reativas de Oxigênio , Tetraciclina , Águas Residuárias , Tetraciclina/química , Carvão Vegetal/química , Espécies Reativas de Oxigênio/química , Águas Residuárias/química , Ferro/química , Poluentes Químicos da Água/química , Peróxidos/química , Transporte de Elétrons
5.
Environ Res ; 252(Pt 3): 119067, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38704002

RESUMO

Environmentally persistent free radicals (EPFRs) can pose exposure risks by inducing the generation of reactive oxygen species. As a new class of pollutants, EPFRs have been frequently detected in atmospheric particulate matters. In this study, the seasonal variations and sources of EPFRs in a severe cold region in Northeastern China were comprehensively investigated, especially for the high pollution events. The geomean concentration of EPFRs in the total suspended particle was 6.58 × 1013 spins/m3 and the mean level in winter was one order of magnitude higher than summer and autumn. The correlation network analysis showed that EPFRs had significantly positive correlation with carbon component, K+ and PAHs, indicating that EPFRs were primarily emitted from combustion and pyrolysis process. The source appointment by the Positive Matrix Factorization (PMF) model indicated that the dominant sources in the heating season were coal combustion (48.4%), vehicle emission (23.1%) and biomass burning (19.4%), while the top three sources in the non-heating season were others (41.4%), coal combustion (23.7%) and vehicle emissions (21.2%). It was found that the high EPFRs in cold season can be ascribed to the extensive use of fossil fuel for heating demand; while the high EPFRs occurred in early spring were caused by the large-scale opening combustion of biomass. In summary, this study provided important basic information for better understanding the pollution characteristics of EPFRs, which suggested that the implementation of energy transformation and straw utilization was benefit for the control of EPFRs in severe cold region.


Assuntos
Poluentes Atmosféricos , Carvão Mineral , Monitoramento Ambiental , Estações do Ano , Poluentes Atmosféricos/análise , Carvão Mineral/análise , China , Radicais Livres/análise , Biomassa , Material Particulado/análise , Cidades , Poluição do Ar/análise
6.
Sci Total Environ ; 933: 172935, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38703859

RESUMO

The deleterious impact of pollution point sources on the surrounding environment and human has long been a focal point of environmental research. When considering the local atmospheric dispersion of semi-volatile organic compounds (SVOCs) around the emission sites, it is essential to account the dynamic process for the gas/particle (G/P) partitioning, which involves the transition from an initial state to a steady state. In this study, we have developed a model that enables the prediction of the dynamic process for G/P partitioning of SVOCs, particularly considering the influence from emission. It is important to note that the dynamic processes of the concentrations of SVOCs in particle phase (CP) and in gas phase (CG) differ significantly. These differences arise due to the influence of two critical factors: particulate proportion of SVOCs in the emissions (ϕ0) and octanol-air partitioning coefficient (KOA). The validity of our model was assessed by comparing its predictions of the extremum value of the G/P partitioning quotient (KP) with the results obtained from the steady-state model. Remarkably, the characteristic time (tC), used to evaluate the timescale required for SVOCs to reach steady state, demonstrated different variations with KOA for CP and CG. Additionally, the values of tC were quite different for CP and CG, which were markedly influenced by ϕ0. For some SVOCs with high KOA values, it took approximately 35 h to reach steady state. Furthermore, it was found that the time to achieve 95 % of steady state (t95 ≈ 3tC) could reach approximately 105 h. This duration is sufficient for chemicals to disperse from their emission site to the surrounding areas. Therefore, it is crucial to consider the dynamic process of G/P partitioning in local atmospheric transport studies. Moreover, the influence of ϕ0 should be incorporated into future investigations examining the dynamic process of G/P partitioning.

7.
Virol J ; 21(1): 116, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783310

RESUMO

OBJECTIVE: Cystic echinococcosis (CE) represents a profoundly perilous zoonotic disease. The advent of viral macrogenomics has facilitated the exploration of hitherto uncharted viral territories. In the scope of this investigation, our objective is to scrutinize disparities in the intestinal microbiotic ecosystems of canines dwelling in elevated terrains and those afflicted by Echinococcus infection, employing the tool of viral macrogenomics. METHODS: In this study, we collected a comprehensive total of 1,970 fecal samples from plateau dogs infected with Echinococcus, as well as healthy control plateau dogs from the Yushu and Guoluo regions in the highland terrain of China. These samples were subjected to viral macrogenomic analysis to investigate the viral community inhabiting the canine gastrointestinal tract. RESULTS: Our meticulous analysis led to the identification of 136 viral genomic sequences, encompassing eight distinct viral families. CONCLUSION: The outcomes of this study hold the potential to enhance our comprehension of the intricate interplay between hosts, parasites, and viral communities within the highland canine gut ecosystem. Through the examination of phage presence, it may aid in early detection or assessment of infection severity, providing valuable insights into Echinococcus infection and offering prospects for potential treatment strategies.


Assuntos
Doenças do Cão , Equinococose , Echinococcus , Fezes , Microbioma Gastrointestinal , Animais , Cães , Equinococose/veterinária , Doenças do Cão/parasitologia , Doenças do Cão/microbiologia , Doenças do Cão/virologia , China , Fezes/parasitologia , Fezes/microbiologia , Fezes/virologia , Echinococcus/genética , Echinococcus/isolamento & purificação , Genoma Viral , Vírus/classificação , Vírus/isolamento & purificação , Vírus/genética
8.
J Hazard Mater ; 473: 134643, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38776815

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) have the capability for solar radiation absorption related to climate forcing. Herein, pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles in a cold megacity were comprehensively investigated. The mean concentrations of Σ18PAHs in all the 11 particle size ranges were 3.95 ± 4.77 × 104 pg/m3 and 2.17 ± 1.54 × 103 pg/m3 in heating period (HP) and non-heating period (NHP), respectively. Except for most PAHs with 2 and 3 benzene rings in NHP, most other PAHs showed a unimodal distribution pattern with the peak at 0.56-1.0 µm in both periods, which was caused by PAH emission sources. The PAH-related climate forcing was mainly caused by the solar radiation absorptions at ∼325 (∼330) nm and ∼365 nm. In general, the absorption intensities were higher in HP than NHP. The absorption intensity in the particle size range of 0.56-1.0 µm was the highest, and benzo[e]pyrene was the dominant contributor. In colder periods in HP, higher PAH concentrations caused more intensive PAH-related climate forcing. This study provided new insights for pollution characteristics and absorption spectra of size-resolved PAHs in atmospheric particles, which will be useful for better understanding PAH-related climate forcing.

9.
J Environ Manage ; 357: 120732, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38560954

RESUMO

Pharmaceutical compounds (PhCs) pose a growing concern with potential environmental impacts, commonly introduced into the environment via wastewater treatment plants (WWTPs). The occurrence, removal, and season variations of 60 different classes of PhCs were investigated in the baffled bioreactor (BBR) wastewater treatment process during summer and winter. The concentrations of 60 PhCs were 3400 ± 1600 ng/L in the influent, 2700 ± 930 ng/L in the effluent, and 2400 ± 120 ng/g dw in sludge. Valsartan (Val, 1800 ng/L) was the main contaminant found in the influent, declining to 520 ng/L in the effluent. The grit chamber and BBR tank were substantially conducive to the removal of VAL. Nonetheless, the BBR process showcased variable removal efficiencies across different PhC classes. Sulfadimidine had the highest removal efficiency of 87 ± 17% in the final effluent (water plus solid phase). Contrasting seasonal patterns were observed among PhC classes within BBR process units. The concentrations of many PhCs were higher in summer than in winter, while some macrolide antibiotics exhibited opposing seasonal fluctuations. A thorough mass balance analysis revealed quinolone and sulfonamide antibiotics were primarily eliminated through degradation and transformation in the BBR process. Conversely, 40.2 g/d of macrolide antibiotics was released to the natural aquatic environment via effluent discharge. Gastric acid and anticoagulants, as well as cardiovascular PhCs, primarily experienced removal through sludge adsorption. This study provides valuable insights into the intricate dynamics of PhCs in wastewater treatment, emphasizing the need for tailored strategies to effectively mitigate their release and potential environmental risks.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Águas Residuárias , Esgotos/análise , Eliminação de Resíduos Líquidos , Estações do Ano , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Antibacterianos/análise , Medição de Risco , Macrolídeos/análise , Preparações Farmacêuticas
10.
Cell Commun Signal ; 22(1): 245, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671456

RESUMO

BACKGROUND: The alveolar epithelial type II cell (AT2) and its senescence play a pivotal role in alveolar damage and pulmonary fibrosis. Cell circadian rhythm is strongly associated with cell senescence. Differentiated embryonic chondrocyte expressed gene 1 (DEC1) is a very important circadian clock gene. However, the role of DEC1 in AT2 senescence and pulmonary fibrosis was still unclear. RESULTS: In this study, a circadian disruption model of light intervention was used. It was found that circadian disruption exacerbated pulmonary fibrosis in mice. To understand the underlying mechanism, DEC1 levels were investigated. Results showed that DEC1 levels increased in lung tissues of IPF patients and in bleomycin-induced mouse fibrotic lungs. In vitro study revealed that bleomycin and TGF-ß1 increased the expressions of DEC1, collagen-I, and fibronectin in AT2 cells. Inhibition of DEC1 mitigated bleomycin-induced fibrotic changes in vitro and in vivo. After that, cell senescence was observed in bleomycin-treated AT2 cells and mouse models, but these were prevented by DEC1 inhibition. At last, p21 was confirmed having circadian rhythm followed DEC1 in normal conditions. But bleomycin disrupted the circadian rhythm and increased DEC1 which promoted p21 expression, increased p21 mediated AT2 senescence and pulmonary fibrosis. CONCLUSIONS: Taken together, circadian clock protein DEC1 mediated pulmonary fibrosis via p21 and cell senescence in alveolar epithelial type II cells.


Assuntos
Bleomicina , Senescência Celular , Ritmo Circadiano , Fibrose Pulmonar , Animais , Humanos , Masculino , Camundongos , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ritmo Circadiano/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/patologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Fator de Crescimento Transformador beta1/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
11.
Cereb Cortex ; 34(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38629796

RESUMO

Neuroimaging studies have shown that the neural representation of imagery is closely related to the perception modality; however, the undeniable different experiences between perception and imagery indicate that there are obvious neural mechanism differences between them, which cannot be explained by the simple theory that imagery is a form of weak perception. Considering the importance of functional integration of brain regions in neural activities, we conducted correlation analysis of neural activity in brain regions jointly activated by auditory imagery and perception, and then brain functional connectivity (FC) networks were obtained with a consistent structure. However, the connection values between the areas in the superior temporal gyrus and the right precentral cortex were significantly higher in auditory perception than in the imagery modality. In addition, the modality decoding based on FC patterns showed that the FC network of auditory imagery and perception can be significantly distinguishable. Subsequently, voxel-level FC analysis further verified the distribution regions of voxels with significant connectivity differences between the 2 modalities. This study complemented the correlation and difference between auditory imagery and perception in terms of brain information interaction, and it provided a new perspective for investigating the neural mechanisms of different modal information representations.


Assuntos
Córtex Auditivo , Mapeamento Encefálico , Mapeamento Encefálico/métodos , Imaginação , Encéfalo/diagnóstico por imagem , Percepção Auditiva , Córtex Cerebral , Imageamento por Ressonância Magnética/métodos , Córtex Auditivo/diagnóstico por imagem
12.
Sci Total Environ ; 924: 171589, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38461988

RESUMO

Pharmaceuticals and personal care products (PPCPs) have attracted wide attention due to their environmental impacts and health risks. PPCPs released through wastewater treatment plants (WWTPs) are estimated to be 80 %. Nevertheless, the occurrence of PPCPs in the WWTPs equipped with Bacillus spec.-based bioreactors (BBR) treatment system remains unclear. In this study, sludge and waste water samples were collected during separate winter and summer sampling campaigns from a typical BBR treatment system. The results indicate that out of 58 target PPCPs, 27 compounds were detected in the waste water (0.06-1900 ng/L), and 23 were found in the sludge (0.6-7755 ng/g dw). Paraxanthine was the chemical of the highest abundance in the influent due to the high consumption of the parent compounds caffeine and theobromine. The profile for PPCPs in the wastewater and sludge exhibited no seasonal variation. Overall, the removal of target PPCPs in summer is more effective than the winter. In the BBR bio-reactor, it was found that selected PPCPs (at ng/L level) can be completely removed. The efficiency for individual PPCP removal was increased from 1.0 % to 50 % in this unit, after target specific adjustments of the process. The effective removal of selected PPCPs by the BBR treatment system is explained by combined sorption and biodegradation processing. The re-occurrence of PPCPs in the wastewater was monitored. Negative removal efficiency was explained by the cleavage of Phase II metabolites after the biotransformation process, and the lack of equilibrium for PPCPs in the sludge of the second clarifier. A compound specific risk quotient (RQ) was calculated and applied for studying the potential environmental risks. Diphenhydramine is found with the highest environmental risk in wastewater, and 15 other PPCPs show negligible risks in sewage sludge.


Assuntos
Cosméticos , Poluentes Químicos da Água , Purificação da Água , Águas Residuárias , Esgotos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Cosméticos/análise , Purificação da Água/métodos , Preparações Farmacêuticas , Monitoramento Ambiental
13.
Environ Pollut ; 347: 123674, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38458517

RESUMO

Fine particulate matter (PM2.5) has been linked to increased severity and incidence of airway diseases, especially chronic obstructive pulmonary disease (COPD) and asthma. Airway remodeling is an important event in both COPD and asthma, and airway smooth muscle cells (ASMCs) are key cells which directly involved in airway remodeling. However, it was unclear how PM2.5 affected ASMCs. This study investigates the effects of PM2.5 on airway smooth muscle and its mechanism. We first showed that inhaled particulate matter was distributed in the airway smooth muscle bundle, combined with increased airway smooth muscle bundle and collagen deposition in vivo. Then, we demonstrated that PM2.5 induced up-regulation of collagen-I and alpha-smooth muscle actin (α-SMA) expression in rat and human ASMCs in vitro. Next, we found PM2.5 led to rat and human ASMCs senescence and exhibited senescence-associated secretory phenotype (SASP) by autophagy-induced GATA4/TRAF6/NF-κB signaling, which contributed to collagen-I and α-SMA synthesis as well as airway smooth muscle remodeling. Together, our results provided evidence that SASP induced by PM2.5 in airway smooth muscle cells prompted airway remodeling.


Assuntos
Asma , Doença Pulmonar Obstrutiva Crônica , Humanos , Ratos , Animais , Remodelação das Vias Aéreas , Fenótipo Secretor Associado à Senescência , Miócitos de Músculo Liso , Asma/metabolismo , Doença Pulmonar Obstrutiva Crônica/induzido quimicamente , Doença Pulmonar Obstrutiva Crônica/metabolismo , Colágeno Tipo I , Proliferação de Células , Material Particulado/metabolismo , Células Cultivadas
14.
Nanoscale Adv ; 6(5): 1374-1379, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38419875

RESUMO

Copper hydrides are highly active catalysts in hydrogenation reactions and reduction processes. Three Stryker-type copper hydride nanoclusters (NCs), [(TPP)CuH]6, [(TCP)CuH]6 and [(TOP)CuH]6 (TPP = triphenylphosphine, TCP = tricyclohexylphosphine and TOP = tri-n-octylphosphine), were synthesized in this study. Due to variations in the electron-donating properties of the phosphine ligands, the UV-visible absorption spectra of the three NCs exhibited notable distinctions. The influence of the phosphine ligands on the effectiveness of the NCs as hydride sources in hydrogenation processes, as well as on the applicability as homogeneous catalysts for reduction reactions, was systematically studied. Due to the highest electron-donating properties of the TOP ligand, [(TOP)CuH]6 was found to exhibit superior performance in both hydrogenation reactions and catalytic reduction reactions. Moreover, these hydrophobic NCs worked well as heterogeneous catalysts in the reduction of 4-nitrophenol.

15.
Nanoscale ; 16(10): 5115-5122, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38369889

RESUMO

Lead sulfide colloidal quantum dots (PbS CQDs) show great potential in next-generation photovoltaics. However, their high specific surface area and complex surface crystallography lead to a high surface trap density, which normally requires more than one type of capping ion or ligand to achieve effective surface passivation. In this study, we performed in situ mixed halogen passivation (MHP) during the direct synthesis of semiconducting PbS CQD inks by using different lead halogens. The different halogens can bind with the surface of the CQD throughout the nucleation/growth process, resulting in optimal surface configuration. As a result, the MHP CQD exhibited superior surface passivation compared to the conventionally iodine-capped CQDs. Finally, we achieved a substantial improvement in efficiency from 10.64% to 12.58% after the MHP treatment. Our work demonstrates the advantages of exploring efficient passivation in the directly synthesized CQD inks.

16.
J Am Chem Soc ; 146(7): 4913-4921, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38319594

RESUMO

Colloidal quantum dots with lower surface ligand density are desired for preparing the active layer for photovoltaic, lighting, and other potential optoelectronic applications. In emerging perovskite quantum dots (PQDs), the diffusion of cations is thought to have a high energy barrier, relative to that of halide anions. Herein, we investigate the fast cross cation exchange approach in colloidal lead triiodide PQDs containing methylammonium (MA+) and formamidinium (FA+) organic cations, which exhibits a significantly lower exchange barrier than inorganic cesium (Cs+)-FA+ and Cs+-MA+ systems. First-principles calculations further suggest that the fast internal cation diffusion arises due to a lowering in structural distortions and the consequent decline in attractive cation-cation and cation-anion interactions in the presence of organic cation vacancies in mixed MA+-FA+ PQDs. Combining both experimental and theoretical evidence, we propose a vacancy-assisted exchange model to understand the impact of structural features and intermolecular interaction in PQDs with fewer surface ligands. Finally, for a realistic outcome, the as-prepared mixed-cation PQDs display better photostability and can be directly applied for one-step coated photovoltaic and photodetector devices, achieving a high photovoltaic efficiency of 15.05% using MA0.5FA0.5PbI3 PQDs and more precisely tunable detective spectral response from visible to near-infrared regions.

17.
Plant Dis ; 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38386296

RESUMO

This study identified a new species (Cercospora Polygonatum) that causes gray leaf spot (GLS) disease in cultivated Polygonatum cyrtonema. This fungal species was isolated from the affected region of GLS on P. cyrtonema leaves. Pathogenicity bioassays were conducted based on Koch's postulates. Morphology was examined based on the features of conidiomata, conidiogenous loci, conidia/conidiophores, and conidiogenous cells. The rDNA internal transcribed spacer region, calmodulin, translation elongation factor 1-alpha, and histone genes were subjected to phylogenetic analysis using MrBayes tool via in Phylosuite. Bootstrap support analysis for phylogenetic placement confirmed the new species, which was significantly different from the closely related species C. senecionis-walkeri and C. zeae-maydis. The morphological characteristics also supported this finding, with the conidiogenous of C. polygonatum being considerably shorter than those of C. senecionis-walkeri or C. zeae-maydis. In addition, C. polygonatum was distinguished by its cultural characteristics. As this fungus was isolated from P. cyrtonema, it was named C. polygonatum F.Q. Yin, M. Liu&W. L. Ma, sp. nov. The type specimen (H8-2) was preserved at the China General Microbiological Culture Collection Center. This is the first report of GLS caused by C. polygonatum on P. cyrtonema leaves in China. The current study enriches the knowledge regarding Cercospora sp., contributes to the identification of a species causing GLS in P. cyrtonema, and provides useful information for the effective management of this disease.

18.
Nanoscale ; 16(8): 4014-4024, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38349080

RESUMO

Immobilizing metal nanoparticles on a support is crucial for catalysts' stability and spatial distribution. MXenes are promising substrates for in situ growth engineering of various electrocatalysts owing to their merits. A stronger binding capacity can be achieved between the in situ-fabricated catalysts and MXenes compared to a common physical combination. Thus, synergistically utilizing morphology modulation, composition optimization, and the interfacial interaction between metal catalysts and supports will maximize the electrocatalytic activity. However, most reported in situ-formed catalysts on MXenes result in solid 0D nanoparticles and in situ growth of nanoalloy catalysts on MXenes with a precisely controlled morphology is still lacking. Herein, nanodendritic PdNi alloys are in situ grown on nitrogen-doped V2CTx, serving as efficient electrocatalysts toward the hydrogen evolution reaction (HER). Thanks to the synergistic effect of the unique nanodendritic structure of PdNi, the merits of N-TBA-V2CTx nanosheets, and the strong metal-support interaction between the PdNi and the N-TBA-V2CTx support, the in situ-formed Pd58Ni42/N-TBA-V2CTx electrocatalyst shows excellent HER performance with an ultralow overpotential of 44.1 mV to achieve 10 mA cm-2 and a lowest Tafel slope of 39.4 mV dec-1, which outperforms Pd58Ni42/TBA-V2CTx, Pd58Ni42, and Pd/C. Remarkably, the Pd58Ni42/N-TBA-V2CTx catalyst can maintain 92.3% of its initial activity even after 50 h of continuous operation.

19.
J Nat Prod ; 87(2): 371-380, 2024 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-38301035

RESUMO

Thiazole scaffold-based small molecules exhibit a range of biological activities and play important roles in drug discovery. Based on bioinformatics analysis, a putative biosynthetic gene cluster (BGC) for thiazole-containing compounds was identified from Streptomyces sp. SCSIO 40020. Heterologous expression of this BGC led to the production of eight new thiazole-containing compounds, grisechelins E, F, and I-N (1, 2, 5-10), and two quinoline derivatives, grisechelins G and H (3 and 4). The structures of 1-10, including their absolute configurations, were elucidated by HRESIMS, NMR spectroscopic data, ECD calculations, and single-crystal X-ray diffraction analysis. Grisechelin F (2) is a unique derivative, distinguished by the presence of a salicylic acid moiety. The biosynthetic pathway for 2 was proposed based on bioinformatics analysis and in vivo gene knockout experiments. Grisechelin E (1) displayed moderate antimycobacterial activity against Mycobacterium tuberculosis H37Ra (MIC of 8 µg mL-1).


Assuntos
Streptomyces , Streptomyces/genética , Streptomyces/química , Antibacterianos/farmacologia , Espectroscopia de Ressonância Magnética , Ácido Salicílico , Tiazóis
20.
J Med Chem ; 67(3): 1914-1931, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38232131

RESUMO

Decaprenylphosphoryl-ß-d-ribose oxidase (DprE1) is a promising target for treating tuberculosis (TB). Currently, most novel DprE1 inhibitors are discovered through high-throughput screening, while computer-aided drug design (CADD) strategies are expected to promote the discovery process. In this study, with the aid of structure-based virtual screening and computationally guided design, a series of novel scaffold N-(1-(6-oxo-1,6-dihydropyrimidine)-pyrazole) acetamide derivatives with significant antimycobacterial activities were identified. Among them, compounds LK-60 and LK-75 are capable of effectively suppressing the proliferation of Mtb with MICMtb values of 0.78-1.56 µM, comparable with isoniazid and much superior to the phase II candidate TBA-7371 (MICMtb = 12.5 µM). LK-60 is also the most active DprE1 inhibitor derived from CADD so far. Further studies confirmed their high affinity to DprE1, good safety profiles to gut microbiota and human cells, and synergy effects with either rifampicin or ethambutol, indicating their broad potential for clinical applications.


Assuntos
Mycobacterium tuberculosis , Humanos , Antituberculosos/farmacologia , Oxirredutases do Álcool , Pirazóis/farmacologia , Acetamidas/farmacologia , Proteínas de Bactérias
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA