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1.
Soft Matter ; 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39344487

RESUMEN

Amphiphilic polymers in aqueous solutions can self-assemble to form bilayer membranes, and their elastic properties can be captured using the well-known Helfrich model involving several elastic constants. In this paper, we employ the self-consistent field model to simulate sinusoidal bilayers self-assembled from diblock copolymers where an appropriate constraint term is introduced to stabilize periodic bilayers with prescribed amplitudes. Then, we devise several methods to extract the shape of these bilayers and examine the accuracy of the free energy predicted by the Helfrich model. Numerical results show that when the bilayer curvature is small, the Helfrich model predicts the excess free energy more accurately. However, when the curvature is large, the accuracy heavily depends on the method used to determine the shape of the bilayer. In addition, the dependence of free energy on interaction strength, constraint amplitude, and constraint period are systematically studied. Moreover, we have devised a method for attaining equilibrium states through the adjustment of constraints. Within the self-consistent field model, these equilibrium states manifest as distinct periodic cylindrical bilayers, which are consonant with the theoretical predictions formulated using the shape equations.

2.
Catal Sci Technol ; 14(18): 5405-5421, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39290873

RESUMEN

Non-thermal plasma-based NO x synthesis from ambient air is receiving an increasing amount of interest for its potential in small-scale, sustainable fertilizer production. Nevertheless, most reported research focuses on lab-scale systems and a single reactor with limited production. In this work, two gliding arc reactors (GARs) with 2 mm discharge gaps were connected in series or in parallel to explore strategies for scaling up the productivity. A single GAR with an enlarged discharge gap of 4 mm was also investigated for comparison. Operation parameters such as flow rate, discharge power & mode, and effective residence time were tested. The NO x concentration increased for all configurations with an increase in specific energy input (SEI), and effective residence time. The case of reactors connected in series outperformed all other configurations. The energy consumptions and NO x productions achieved were 2.29-2.42 MJ molN -1 and 124.6-158.3 mmolN h-1, respectively. The NO2 selectivity could be enhanced by prolonging the post-plasma oxidation time while consuming the excess O2 in the feed and utilizing the low temperatures at the reactor(s) outlet. By using this connection strategy, NO x production can be doubled with a 20.9% improvement in energy consumption compared to a single reactor.

4.
ACS Sustain Chem Eng ; 12(29): 10841-10853, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39055865

RESUMEN

Plasma-sorbent systems are a novel technology for single-stage carbon capture and utilization (CCU), where the plasma enables the desorption of CO2 from a sorbent and the simultaneous conversion to CO. In this study, we test the flexibility of a plasma-sorbent system in a single unit, specifically for sorption-enhanced dry reforming of methane (DRM). The experimental results indicate the selective adsorption of CO2 by the sorbent zeolite 5A in the first step, and CH4 addition during the plasma-based desorption of CO2 enables DRM to various value-added products in the second step, such as H2, CO, hydrocarbons, and the byproduct H2O. Furthermore, our work also demonstrates that zeolite has the potential to increase the conversion of CO2 and CH4, attributed to its capability to capture H2O. Aside from the notable carbon deposition, material analysis shows that the zeolite remains relatively stable under plasma exposure.

6.
Plant Cell Environ ; 47(11): 4293-4304, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38963294

RESUMEN

NAC-domain transcription factors (TFs) are plant-specific transcriptional regulators playing crucial roles in plant secondary cell wall (SCW) biosynthesis. SCW is important for plant growth and development, maintaining plant morphology, providing rigid support, ensuring material transportation and participating in plant stress responses as a protective barrier. However, the molecular mechanisms underlying SCW in eggplant have not been thoroughly explored. In this study, the NAC domain TFs SmNST1 and SmNST2 were cloned from the eggplant line 'Sanyue qie'. SmNST1 and SmNST2 expression levels were the highest in the roots and stems. Subcellular localization analysis showed that they were localized in the cell membrane and nucleus. Their overexpression in transgenic tobacco showed that SmNST1 promotes SCW thickening. The expression of a set of SCW biosynthetic genes for cellulose, xylan and lignin, which regulate SCW formation, was increased in transgenic tobacco. Bimolecular fluorescence and luciferase complementation assays showed that SmNST1 interacted with SmNST2 in vivo. Yeast one-hybrid, electrophoretic mobility shift assay (EMSA) and Dual-luciferase reporter assays showed that SmMYB26 directly bound to the SmNST1 promoter and acted as an activator. SmNST1 and SmNST2 interact with the SmMYB108 promoter and repress SmMYB108 expression. Altogether, we showed that SmNST1 positively regulates SCW formation, improving our understanding of SCW biosynthesis transcriptional regulation.


Asunto(s)
Pared Celular , Regulación de la Expresión Génica de las Plantas , Nicotiana , Proteínas de Plantas , Plantas Modificadas Genéticamente , Solanum melongena , Factores de Transcripción , Pared Celular/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Nicotiana/genética , Nicotiana/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Solanum melongena/genética , Solanum melongena/metabolismo , Regiones Promotoras Genéticas/genética
7.
Sci Rep ; 14(1): 16031, 2024 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-38992201

RESUMEN

O6-methylguanine-DNA methyltransferase (MGMT) has been demonstrated to be an important prognostic and predictive marker in glioblastoma (GBM). To establish a reliable radiomics model based on MRI data to predict the MGMT promoter methylation status of GBM. A total of 183 patients with glioblastoma were included in this retrospective study. The visually accessible Rembrandt images (VASARI) features were extracted for each patient, and a total of 14676 multi-region features were extracted from enhanced, necrotic, "non-enhanced, and edematous" areas on their multiparametric MRI. Twelve individual radiomics models were constructed based on the radiomics features from different subregions and different sequences. Four single-sequence models, three single-region models and the combined radiomics model combining all individual models were constructed. Finally, the predictive performance of adding clinical factors and VASARI characteristics was evaluated. The ComRad model combining all individual radiomics models exhibited the best performance in test set 1 and test set 2, with the area under the receiver operating characteristic curve (AUC) of 0.839 (0.709-0.963) and 0.739 (0.581-0.897), respectively. The results indicated that the radiomics model combining multi-region and multi-parametric MRI features has exhibited promising performance in predicting MGMT methylation status in GBM. The Modeling scheme that combining all individual radiomics models showed best performance among all constructed moels.


Asunto(s)
Neoplasias Encefálicas , Metilación de ADN , Metilasas de Modificación del ADN , Enzimas Reparadoras del ADN , Glioblastoma , Proteínas Supresoras de Tumor , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/patología , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Glioblastoma/genética , Glioblastoma/diagnóstico por imagen , Glioblastoma/patología , Imagen por Resonancia Magnética/métodos , Pronóstico , Regiones Promotoras Genéticas , Radiómica , Estudios Retrospectivos , Curva ROC , Proteínas Supresoras de Tumor/genética
8.
Med Rev (2021) ; 4(3): 173-191, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38919400

RESUMEN

As a key sensor of double-stranded DNA (dsDNA), cyclic GMP-AMP synthase (cGAS) detects cytosolic dsDNA and initiates the synthesis of 2'3' cyclic GMP-AMP (cGAMP) that activates the stimulator of interferon genes (STING). This finally promotes the production of type I interferons (IFN-I) that is crucial for bridging innate and adaptive immunity. Recent evidence show that several antitumor therapies, including radiotherapy (RT), chemotherapy, targeted therapies and immunotherapies, activate the cGAS-STING pathway to provoke the antitumor immunity. In the last decade, the development of STING agonists has been a major focus in both basic research and the pharmaceutical industry. However, up to now, none of STING agonists have been approved for clinical use. Considering the broad expression of STING in whole body and the direct lethal effect of STING agonists on immune cells in the draining lymph node (dLN), research on the optimal way to activate STING in tumor microenvironment (TME) appears to be a promising direction. Moreover, besides enhancing IFN-I signaling, the cGAS-STING pathway also plays roles in senescence, autophagy, apoptosis, mitotic arrest, and DNA repair, contributing to tumor development and metastasis. In this review, we summarize the recent advances on cGAS-STING pathway's response to antitumor therapies and the strategies involving this pathway for tumor treatment.

9.
Vaccine ; 42(22): 126004, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-38797627

RESUMEN

BACKGROUND: We recently reported a near disappearance of B. pertussis and a decline in anti-B. pertussis antibodies during the peak implementation of Coronavirus disease 2019 (COVID-19) non-pharmaceutical interventions (NPI) in 2021 in British Columbia (BC), Canada. During 2021-2023, incidence of reported B. pertussis cases remained low in BC at < 1/100,000 population. This study determined how serological evidence of B. pertussis changed after the gradual relaxation of NPI between 2021-2023. METHODS: Randomly selected blood samples from school staff 25-51 years old (n = 65) were collected yearly between 2021-2023 in the Vancouver metropolitan area, BC, Canada, and tested for anti-pertussis toxin (PT) IgG levels. Serological evidence of B. pertussis infection (thereafter "seroconversion") was defined as a quantifiable anti-PT IgG levels in subjects with anti-PT IgG levels below lower limit of quantification in the preceding year or a > 4-fold increase in anti-PT IgG levels between two subsequent years. Samples were also tested for anti-diphtheria toxoid (DT) IgG, and similar seroconversion criteria were applied to exclude seroconversion due to vaccination with tetanus-diphtheria-acellular-pertussis (Tdap). RESULTS: Three subjects met seroconversion criteria for anti-PT IgG between 2021 and 2022 and 9 between 2022 and 2023, yielding a seroconversion rate of 4.6 /100 person-years and 14.9/100 person-years, P = 0.127, respectively. None of the subjects met the criteria for vaccination with Tdap. The geometric mean concentration of anti-PT IgG showed a statistically significant decrease in 2022 compared with 2021, 4.8 IU/mL IU/ml (95 % confidence interval [CI], 3.8-5.9) vs. 6.4 IU/ml (95 % CI, 4.9-8.2; p = 0.001), followed by a statistically significant increase in 2023 compared with 2022 6.5 IU/ml (95 % CI, 4.9-8.5) vs. 4.8 IU/ml (95 % CI, 3.8-5.9; p = 0.0006), respectively. DISCUSSION: Serological evidence of B. pertussis increased between 2022 and 2023 despite low reported cases, which suggests that B. pertussis circulation resumed after relaxing of COVID-19 NPI.


Asunto(s)
Anticuerpos Antibacterianos , Bordetella pertussis , COVID-19 , Inmunoglobulina G , Tos Ferina , Humanos , Tos Ferina/prevención & control , Tos Ferina/inmunología , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/epidemiología , Colombia Británica/epidemiología , Bordetella pertussis/inmunología , Adulto , Persona de Mediana Edad , Femenino , Masculino , Inmunoglobulina G/sangre , Anticuerpos Antibacterianos/sangre , SARS-CoV-2/inmunología , Toxina del Pertussis/inmunología , Seroconversión
10.
One Health ; 18: 100736, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38694616

RESUMEN

The growth in ecotourism and nature-based recreational activities in China has resulted in an increased frequency of visits to green spaces, thereby elevating exposure to ticks and the subsequent risk of tick-borne diseases. This study comprehensively investigate individual behavioral and cognitive factors associated with the risk of contracting tick-borne diseases to facilitate the development of effective prevention and control strategies, supporting public health initiatives in high-prevalence regions. We conducted an extensive questionnaire survey among 3000 residents from three northeastern provinces in China (Heilongjiang, Jilin, and Liaoning), where tick-borne diseases exhibit relatively high prevalence. The survey focused on gathering information regarding participants' tick bite history, perception of tick-borne disease risks, and outdoor activity patterns. Using structural equations analysis, we explored the pathways and strengths of the associations between these factors. Our findings revealed an average self-reported tick bite rate of 14% among the participants. Notably, tick-borne encephalitis exhibited the highest self-reported prevalence of infection (4%) among tick-borne diseases, while both Lyme disease and Severe fever with thrombocytopenia syndrome had a prevalence of 2%. The average rate of tick bites among respondents' pets was 14%, with bites predominantly located on the ears, back, and abdomen. The strongest correlation was observed between tick bite rate and subsequent infections, emphasizing its role as the primary contributing factors to infectious status. Moreover, our results indicated that the causal structure of tick-borne disease infections varied across different cities, underscoring the significance of considering the ecological environment and regional knowledge on ticks. This study provides valuable insights into the current landscape of tick-borne disease infections in northeast China and identifies potential behavioral and cognitive factors, an aspect that has not been previously investigated. Our findings enable predictions on the future impact of knowledge dissemination efforts and improved urban facilities on mitigating tick bites and reducing tick-borne disease infections.

11.
MAGMA ; 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38578520

RESUMEN

OBJECTIVE: To assess the performance of hybrid multi-dimensional magnetic resonance imaging (HM-MRI) in quantifying hematoxylin and eosin (H&E) staining results, grading and predicting isocitrate dehydrogenase (IDH) mutation status of gliomas. MATERIALS AND METHODS: Included were 71 glioma patients (mean age, 50.17 ± 13.38 years; 35 men). HM-MRI images were collected at five different echo times (80-200 ms) with seven b-values (0-3000 s/mm2). A modified three-compartment model with very-slow, slow and fast diffusion components was applied to calculate HM-MRI metrics, including fractions, diffusion coefficients and T2 values of each component. Pearson correlation analysis was performed between HM-MRI derived fractions and H&E staining derived percentages. HM-MRI metrics were compared between high-grade and low-grade gliomas, and between IDH-wild and IDH-mutant gliomas. Using receiver operational characteristic (ROC) analysis, the diagnostic performance of HM-MRI in grading and genotyping was compared with mono-exponential models. RESULTS: HM-MRI metrics FDvery-slow and FDslow demonstrated a significant correlation with the H&E staining results (p < .05). Besides, FDvery-slow showed the highest area under ROC curve (AUC = 0.854) for grading, while Dslow showed the highest AUC (0.845) for genotyping. Furthermore, a combination of HM-MRI metrics FDvery-slow and T2Dslow improved the diagnostic performance for grading (AUC = 0.876). DISCUSSION: HM-MRI can aid in non-invasive diagnosis of gliomas.

12.
Nat Nanotechnol ; 19(6): 856-866, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38480836

RESUMEN

The efficacy of STING (stimulator of interferon genes) agonists is due to various factors, primarily inefficient intracellular delivery, low/lack of endogenous STING expression in many tumours, and a complex balance between tumour control and progression. Here we report a universal STING mimic (uniSTING) based on a polymeric architecture. UniSTING activates STING signalling in a range of mouse and human cell types, independent of endogenous STING expression, and selectively stimulates tumour control IRF3/IFN-I pathways, but not tumour progression NF-κB pathways. Intratumoural or systemic injection of uniSTING-mRNA via lipid nanoparticles (LNPs) results in potent antitumour efficacy across established and advanced metastatic tumour models, including triple-negative breast cancer, lung cancer, melanoma and orthotopic/metastatic liver malignancies. Furthermore, uniSTING displays an effective antitumour response superior to 2'3'-cGAMP and ADU-S100. By favouring IRF3/IFN-I activity over the proinflammatory NF-κB signalling pathway, uniSTING promotes dendritic cell maturation and antigen-specific CD8+ T-cell responses. Extracellular vesicles released from uniSTING-treated tumour cells further sensitize dendritic cells via exosome-containing miRNAs that reduced the immunosuppressive Wnt2b, and a combination of LNP-uniSTING-mRNA with α-Wnt2b antibodies synergistically inhibits tumour growth and prolongs animal survival. Collectively, these results demonstrate the LNP-mediated delivery of uniSTING-mRNA as a strategy to overcome the current STING therapeutic barriers, particularly for the treatment of multiple cancer types in which STING is downregulated or absent.


Asunto(s)
Proteínas de la Membrana , Transducción de Señal , Animales , Humanos , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Transducción de Señal/efectos de los fármacos , Ratones , Línea Celular Tumoral , Factor 3 Regulador del Interferón/metabolismo , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Neoplasias/metabolismo , Femenino , ARN Mensajero/genética , ARN Mensajero/metabolismo , FN-kappa B/metabolismo , Ratones Endogámicos C57BL , Liposomas
13.
J Exp Bot ; 75(11): 3500-3520, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38517318

RESUMEN

Verticillium wilt, a soilborne vascular disease caused by Verticillium dahliae, strongly affects cotton yield and quality. In this study, an isolated rhizosphere bacterium, designated Bacillus velezensis BvZ45-1, exhibited >46% biocontrol efficacy against cotton verticillium wilt under greenhouse and field conditions. Moreover, through crude protein extraction and mass spectrometry analyses, we found many antifungal compounds present in the crude protein extract of BvZ45-1. The purified oxalate decarboxylase Odx_S12 from BvZ45-1 inhibited the growth of V. dahliae Vd080 by reducing the spore yield, causing mycelia to rupture, spore morphology changes, cell membrane rupture, and cell death. Subsequently, overexpression of Odx_S12 in Arabidopsis significantly improved plant resistance to V. dahliae. Through studies of the resistance mechanism of Odx_S12, V. dahliae was shown to produce oxalic acid (OA), which has a toxic effect on Arabidopsis leaves. Odx_S12 overexpression reduced Arabidopsis OA content, enhanced tolerance to OA, and improved resistance to verticillium wilt. Transcriptomics and quantitative real-time PCR analysis revealed that Odx_S12 promoted a reactive oxygen species burst and a salicylic acid- and abscisic acid-mediated defence response in Arabidopsis. In summary, this study not only identified B. velezensis BvZ45-1 as an efficient biological control agent, but also identified the resistance gene Odx_S12 as a candidate for cotton breeding against verticillium wilt.


Asunto(s)
Arabidopsis , Ascomicetos , Bacillus , Carboxiliasas , Gossypium , Enfermedades de las Plantas , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Bacillus/fisiología , Gossypium/genética , Gossypium/microbiología , Gossypium/metabolismo , Carboxiliasas/metabolismo , Carboxiliasas/genética , Arabidopsis/genética , Arabidopsis/microbiología , Arabidopsis/metabolismo , Arabidopsis/inmunología , Ascomicetos/fisiología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Resistencia a la Enfermedad/genética , Verticillium/fisiología
14.
Sheng Wu Gong Cheng Xue Bao ; 40(1): 81-93, 2024 Jan 25.
Artículo en Chino | MEDLINE | ID: mdl-38258633

RESUMEN

The chloroplast genome encodes many key proteins involved in photosynthesis and other metabolic processes, and metabolites synthesized in chloroplasts are essential for normal plant growth and development. Root-UVB (ultraviolet radiation B)-sensitive (RUS) family proteins composed of highly conserved DUF647 domain belong to chloroplast proteins. They play an important role in the regulation of various life activities such as plant morphogenesis, material transport and energy metabolism. This article summarizes the recent advances of the RUS family proteins in the growth and development of plants such as embryonic development, photomorphological construction, VB6 homeostasis, auxin transport and anther development, with the aim to facilitate further study of its molecular regulation mechanism in plant growth and development.


Asunto(s)
Cloroplastos , Rayos Ultravioleta , Femenino , Embarazo , Humanos , Transporte Biológico , Cloroplastos/genética , Desarrollo Embrionario , Desarrollo de la Planta/genética
15.
PLoS Pathog ; 20(1): e1011823, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38236820

RESUMEN

A variety of coordinated host-cell responses are activated as defense mechanisms against pore-forming toxins (PFTs). Bacillus thuringiensis (Bt) is a worldwide used biopesticide whose efficacy and precise application methods limits its use to replace synthetic pesticides in agricultural settings. Here, we analyzed the intestinal defense mechanisms of two lepidopteran insect pests after intoxication with sublethal dose of Bt PFTs to find out potential functional genes. We show that larval intestinal epithelium was initially damaged by the PFTs and that larval survival was observed after intestinal epithelium regeneration. Further analyses showed that the intestinal regeneration caused by Cry9A protein is regulated through c-Jun NH (2) terminal kinase (JNK) and Janus tyrosine kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. JAK/STAT signaling regulates intestinal regeneration through proliferation and differentiation of intestinal stem cells to defend three different Bt proteins including Cry9A, Cry1F or Vip3A in both insect pests, Chilo suppressalis and Spodoptera frugiperda. Consequently, a nano-biopesticide was designed to improve pesticidal efficacy based on the combination of Stat double stranded RNA (dsRNA)-nanoparticles and Bt strain. This formulation controlled insect pests with better effect suggesting its potential use to reduce the use of synthetic pesticides in agricultural settings for pest control.


Asunto(s)
Bacillus thuringiensis , Plaguicidas , Animales , Bacillus thuringiensis/genética , Quinasas Janus/genética , Tirosina , Endotoxinas/genética , Insectos , Spodoptera/genética , Larva , Plaguicidas/farmacología , Regeneración , Proteínas Bacterianas/farmacología , Proteínas Bacterianas/genética , Proteínas Hemolisinas/farmacología , Proteínas Hemolisinas/genética , Plantas Modificadas Genéticamente , Control Biológico de Vectores/métodos
16.
Proc Natl Acad Sci U S A ; 120(50): e2122178120, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-38051771

RESUMEN

Thrombocytopenia, hemorrhage, anemia, and infection are life-threatening issues following accidental or intentional radiation exposure. Since few therapeutics are available, safe and efficacious small molecules to mitigate radiation-induced injury need to be developed. Our previous study showed the synthetic TLR2/TLR6 ligand fibroblast stimulating lipopeptide (FSL-1) prolonged survival and provided MyD88-dependent mitigation of hematopoietic acute radiation syndrome (H-ARS) in mice. Although mice and humans differ in TLR number, expression, and function, nonhuman primate (NHP) TLRs are like those of humans; therefore, studying both animal models is critical for drug development. The objectives of this study were to determine the efficacy of FSL-1 on hematopoietic recovery in small and large animal models subjected to sublethal total body irradiation and investigate its mechanism of action. In mice, we demonstrate a lack of adverse effects, an easy route of delivery (subcutaneous) and efficacy in promoting hematopoietic progenitor cell proliferation by FSL-1. NHP given radiation, followed a day later with a single subcutaneous administration of FSL-1, displayed no adversity but showed elevated hematopoietic cells. Our analyses revealed that FSL-1 promoted red blood cell development and induced soluble effectors following radiation exposure. Cytologic analysis of bone marrow aspirates revealed a striking enhancement of mononuclear progenitor cells in FSL-1-treated NHP. Combining the efficacy of FSL-1 in promoting hematopoietic cell recovery with the lack of adverse effects induced by a single administration supports the application of FSL-1 as a viable countermeasure against H-ARS.


Asunto(s)
Síndrome de Radiación Aguda , Receptor Toll-Like 2 , Humanos , Ratones , Animales , Receptor Toll-Like 6 , Ligandos , Síndrome de Radiación Aguda/tratamiento farmacológico , Primates , Fibroblastos
17.
React Chem Eng ; 8(9): 2223-2233, 2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-38014416

RESUMEN

A novel plate-to-plate dielectric barrier discharge microreactor (micro DBD) has been demonstrated in CO2 splitting. In this design, the ground electrode has a cooling microchannel to maintain the electrode temperature in the 263-298 K range during plasma operation. A small gap size between the electrodes of 0.50 mm allowed efficient heat transfer from the surrounding plasma to the ground electrode surface to compensate for heat released in the reaction zone and maintain a constant temperature. The effect of temperature on CO2 conversion and energy efficiency was studied at a voltage of 6-9 kV, a frequency of 60 kHz and a constant CO2 flow rate of 20 ml min-1. The CO2 decomposition rate first increased and then decreased as the electrode temperature decreased from 298 to 263 K with a maximum rate observed at 273 K. Operation at lower temperatures enhanced the vibrational dissociation of the CO2 molecule as opposed to electronic excitation which is the main mechanism at room temperature in conventional DBD reactors, however it also reduced the rate of elementary reaction steps. The counterplay between these two effects leads to a maximum in the reaction rate. The power consumption monotonously increased as the temperature decreased. The effective capacitance of the reactor increased by 1.5 times at 263 K as compared to that at 298 K changing the electric field distribution inside the plasma zone.

19.
ACS Sustain Chem Eng ; 11(34): 12821-12832, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37654788

RESUMEN

A two-dimensional gliding arc reactor for NOx synthesis was investigated in this study using AC pulsed mode operation. Tests with a duty cycle of 40 or 60% achieved the lowest energy consumption of 6.95 MJ/mol, which is an improvement of 15% from the case of continuous operation. Based on the results achieved, a new method for analyzing the spatial profile of the reactor was presented. The reactor was divided into five zones along the arc propagation, and results indicated that the first zone and last zone of the gliding arc reactor had higher energy consumption (9.59 and 8.63 MJ/mol, respectively), while lower consumption was observed in the middle parts of the reactor with a minimum of 5.00 MJ/mol. Spatial-resolved optical emission spectra, the deduced electron density, and temperature indicated the nonuniformity in plasma properties, which corresponds to the NOx production performance across the reactor. This research provides information and discussion that can be used for understanding and optimization of gliding arc reactors toward efficient nitrogen fixation.

20.
Acta Biochim Biophys Sin (Shanghai) ; 55(9): 1456-1466, 2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37491880

RESUMEN

Homocysteine (Hcy) is a risk factor for multiple chronic diseases, and vascular endothelial cell injury has been regarded as the initiating step for this process. miRNAs are involved in Hcy-induced endothelial dysfunction, while the underlying mechanism and roles of miRNAs in pulmonary endothelial dysfunction induced by homocysteine are unknown. Here, we find that miR-205-5p alleviates pulmonary endothelial dysfunction by targeting FOXO1 in CBS +/‒ mice to protect against Hcy-induced pulmonary endothelial dysfunction. Mechanistically, we show that Hcy can lead to DNA hypermethylation of the miR-205-5p promoter due to the increased binding of DNMT1 to its promoter, which contributes to reduction of miR-205-5p expression. In summary, miR-205-5p promoter hypermethylation causes downregulation of miR-205-5p expression, resulting in a reduction in miR-205-5p binding to FOXO1 during homocysteine-induced pulmonary endothelial dysfunction. Our data indicate that miR-205-5p may be a potential therapeutic target against Hcy-induced pulmonary injury.


Asunto(s)
MicroARNs , Animales , Ratones , Metilación de ADN , Regulación hacia Abajo , Células Endoteliales/metabolismo , Endotelio/metabolismo , MicroARNs/genética , MicroARNs/metabolismo
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