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1.
Dent Mater ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39227233

RESUMEN

OBJECTIVES: To determine the short-term (5 min) initial effects of a high-irradiance light-curing (LC) protocol on light transmission (LT%), radiant exposure (RE) and degree of conversion (DC%) of different bulk-fill resin-based composites (RBCs). MATERIALS AND METHODS: Six bulk-fill composites with different viscosities were investigated: OBF (One Bulk Fill, 3 M), EB (Estelite bulkfill,Tokuyama), PFill, PFlow, ECeram and EFlow (PowerFill, Poweflow, Tetric EvoCeram bulkfill, Tetric Evoflow bulkfill, Ivoclar), subjected to different LC protocols: one ultra-high-intensity (3 W/cm2 -3 s via PowerCure LCU) and two conventional (1.2 W/cm2 -10 s and 20 s via PowerCure and Elipar S10 LCUs). Specimens (n = 5) were polymerized within their molds (ϕ5 mm × 4 mm depth) to determine LT% and RE at 4 mm using a MARC-LC spectrometer. For real-time DC% measurements by FTIR, similar molds were utilized. Data were analyzed by one-way ANOVA and Tukey post-hoc tests at 5 % significance. RESULTS: Regardless of the applied LC protocols, OBF and low-viscosity RBCs (EB, PFlow and EFlow) had the lowest and highest LT%, RE, DC% and RPmax, respectively. RE results of all RBCs were in the same sequence: Elipar-20 s > PCure-10 s > PCure-3 s. DC% of PFill and PFlow displayed no significant difference between the applied LC protocols (p > 0.05). The polymerization kinetic in all materials was well described by an exponential sum function (r2 varied between 0.85 and 0.98), showing a faster polymerization with the PCure-3 s protocol. SIGNIFICANCE: The measurement of LT% and DC% at 5 min gave an insight into the developing polymerization process. The initial response of these bulk-fill composite to a high-irradiation protocol varied depending on their composition and viscosity, being faster for low viscosity materials. Nevertheless, even though multiple resin composites are designed to be efficient during photopolymerization, care should be taken when selecting materials/curing protocol.

2.
iScience ; 27(9): 110806, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39297162

RESUMEN

Halophiles, thriving in harsh saline environments, capture scientific interest due to their remarkable ability to prosper under extreme salinity. This study unveils the distinct salt-induced activation of methionine sulfoxide reductases (MsrA) from Halobacterium hubeiense, showcasing a significant enhancement in enzymatic activity across various salt concentrations ranging from 0.5 to 3.5 M. This contrasts sharply with the activity profiles of non-halophilic counterparts. Through comprehensive molecular dynamics simulations, we demonstrate that salt ions stabilize and compact the enzyme's structure, notably enhancing its substrate affinity. Mutagenesis analysis further confirms the essential role of salt bridges formed by the basic Arg168 residue in salt-induced activation. Mutating Arg168 to an acidic or neutral residue disrupts salt-induced activation, substantially reducing the enzyme activity under salt conditions. Our research provides evidence of salt-activated MsrA activity in halophiles, elucidating the molecular basis of halophilic enzyme activity in response to salts.

3.
Adv Mater ; : e2409406, 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39318076

RESUMEN

High-performance semiconductor devices capable of multiple functions are pivotal in meeting the challenges of miniaturization and integration in advanced technologies. Despite the inherent difficulties of incorporating dual functionality within a single device, a high-performance, dual-mode device is reported. This device integrates an ultra-thin Al2O3 passivation layer with a PbS/Si hybrid heterojunction, which can simultaneously enable optoelectronic detection and neuromorphic operation. In mode 1, the device efficiently separates photo-generated electron-hole pairs, exhibiting an ultra-wide spectral response from ultraviolet (265 nm) to near-infrared (1650 nm) wavelengths. It also reproduces high-quality images of 256 × 256 pixels, achieving a Q-value as low as 0.00437 µW cm- 2 at a light intensity of 8.58 µW cm- 2. Meanwhile, when in mode 2, the as-assembled device with typical persistent photoconductivity (PPC) behavior can act as a neuromorphic device, which can achieve 96.5% accuracy in classifying standard digits underscoring its efficacy in temporal information processing. It is believed that the present dual-function devices potentially advance the multifunctionality and miniaturization of chips for intelligence applications.

4.
Environ Sci Technol ; 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39324746

RESUMEN

Emissions of volatile organic compounds (VOCs) threaten both the environment and human health. To realize the elimination of VOCs, Ru/CeO2 catalysts have been intensively investigated and applied. Although it has been widely acknowledged that the catalytic performance of platinum group metal catalysts was highly determined by their dispersion and coordination environment, the most reactive structures on Ru/CeO2 catalysts for VOCs oxidation are still ambiguous. In this work, starting from Ce-BTC (BTC = 1,3,5-benzenetricarboxylic acid) materials, atomically dispersed Ru catalysts and agglomerated Ru catalysts were successfully created via one-step hydrothermal method (Ru-CeO2-BTC) and conventional incipient wetness impregnation method (Ru/CeO2-BTC), respectively. In a typical model reaction of C3H6 oxidation, atomically dispersed Ruδ+ species with the formation of abundant Ru-O-Ce linkages on Ru-CeO2-BTC were found to perform much better than agglomerated RuOx species on Ru/CeO2-BTC. Further characterizations and mechanism study disclosed that Ru-CeO2-BTC catalyst with atomically dispersed Ru ions and more superior low temperature redox performance compared to Ru/CeO2-BTC could better facilitate the adsorption/activation of C3H6 and the decomposition/desorption of intermediates, thus exhibiting superior C3H6 oxidation activity. This work elucidated the reactive sites on Ru/CeO2 catalysts in the C3H6 oxidation reaction and provided insightful guidance for designing efficient Ru/CeO2 catalysts to eliminate VOCs.

5.
Nat Commun ; 15(1): 6957, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39138222

RESUMEN

The high-intactness and ultraclean fabrication of suspended 2D materials has always been a challenge due to their atomically thin nature. Here, we present a universal polymer-free transfer approach for fabricating suspended 2D materials by using volatile micro-molecule cyclododecane as the transfer medium, thus ensuring the ultraclean and intact surface of suspended 2D materials. For the fabricated monolayer suspended graphene, the intactness reaches 99% for size below 10 µm and suspended size reaches 36 µm. Owing to the advantages of ultra-cleanness and large size, the thermal conductivity reaches 4914 W m - 1 K - 1 at 338 K. Moreover, this strategy can also realize efficient batch transfer of suspended graphene and is applicable for fabricating other 2D suspended materials such as MoS2. Our research not only establishes foundation for potential applications and investigations of intrinsic properties of large-area suspended 2D materials, but also accelerates the wide applications of suspended graphene grid in ultrahigh-resolution TEM characterization.

6.
Front Psychol ; 15: 1277846, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39108425

RESUMEN

Introduction: With the boom in social media, many people spend a lot of time on these platforms. Among them, some developed negative emotions, such as fatigue, depression, or disinterest in communicating, and used social media temporarily or permanently. Therefore, this study aims to explore the antecedents of social media fatigue, including social media helpfulness, social media self-efficacy, online subjective well-being, social comparison, compulsive social media use, privacy concerns, fear of missing out, and information overload, and to further discuss the determinants of social media fatigue on social anxiety and lurking. Methods: An online questionnaire was distributed to social media users, and 659 valid samples were obtained with the help of a purposive sampling strategy. The data was analyzed by the partial least square (PLS) method. Results: The study found that social media self-efficacy had a significant negative effect on social media fatigue; compulsive social media use, fear of missing out, and information overload had a significant positive effect on social media fatigue; and social media fatigue had a significant positive effect on social anxiety and lurking. Discussion: The research results can be used as a reference for social media marketers and internet service providers in developing business strategies.

7.
Carbohydr Polym ; 343: 122484, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39174103

RESUMEN

Cellulose molecules, as the basic unit of biomass cellulose, have demonstrated advancements in versatile engineering and modification of cellulose toward sustainable and promising materials in our low-carbon society. However, harvesting high-quality cellulose molecules from natural cellulosic fibers (CF) remains challenging due to strong hydrogen bonds and unique crystalline structure, which limit solvents (such as ionic liquid, IL) transport and diffusion within CF, making the process energy/time-intensively. Herein, we superfast and sustainably engineer biomass fibers into high-performance cellulose molecules via ethanol pre-swelling of CF followed by IL treatment in the microwave (MW) system. Ethanol-pre-swelled cellulosic fibers (SCF) feature modified morphological and structural distinctions, with improved fiber width, pore size, and specific surface area. The ethanol in the SCF structure is appropriately removed through MW heating and cooling, leaving transport and diffusion pathways of IL within the SCF. Such strategy enables the superfast (140 s) and large-scale (kilogram level) harvesting of cellulose molecules with high molecular weight, resulting in high-performance, versatile cellulose ionogel with a 300 % increase in strength and 1027 % in toughness, monitoring human movement, external pressure, and temperature. Our strategy paves the way for time/energy-effectively, sustainably harvesting high-quality polymer molecules from natural sources beyond cellulose toward versatile and advanced materials.

8.
J Hazard Mater ; 478: 135375, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39141942

RESUMEN

The brominated flame retardant 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) widely used in manufacturing is inevitably released into the environment, resulting in the exposure of organisms to BTBPE. Therefore, it is particularly important to explore its toxic mechanism. The liver is one of the main accumulating organs of BTBPE, but the mechanism underlying BTBPE hepatotoxicity has not been thoroughly investigated. In our study, BTBPE was administered to Sprague-Dawley (SD) rats and rat hepatocytes (BRL cells) in vivo and in vitro, respectively, and HE staining, AO/EB staining, fluorescent probes, qPCR, immunofluorescence, and dual-luciferase reporter assays were performed. We investigated the mechanism of action of growth arrest-specific 5 (GAS5), miR-743a-5p, and NUAK family kinase 1 (NUAK1) in BTBPE-induced necroptosis from the perspective of competing endogenous RNAs (ceRNAs) using NUAK1 inhibitors, siRNAs, mimics, and overexpression plasmids. Our study showed that exposure to BTBPE caused necroptosis in the liver and BRL cells, accompanied by an oxidation-reduction imbalance and an inflammatory response. It is worth noting that NUAK1 is a newly discovered upstream regulatory target for necroptosis. In addition, miR-743a-5p was shown to inhibit necroptosis by targeting NUAK1 and down-regulating NUAK1. GAS5 upregulates NUAK1 expression by competitively binding to miR-743a-5p, thereby inducing necroptosis. This study demonstrated, for the first time, that the GAS5-miR-743a-5p-NUAK1 axis is involved in the regulation of necroptosis via ceRNAs. Thus, GAS5 and NUAK1 induce necroptosis by competitively binding to miR-743a-5p.


Asunto(s)
Hepatocitos , MicroARNs , Necroptosis , Animales , Masculino , Ratas , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Línea Celular , Retardadores de Llama/toxicidad , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , MicroARNs/metabolismo , MicroARNs/genética , Necroptosis/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Ratas Sprague-Dawley , ARN Nucleolar Pequeño
9.
J Mater Chem B ; 12(35): 8733-8745, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39138950

RESUMEN

Graphene oxide (GO) is a two-dimensional metastable nanomaterial. Interestingly, GO formed oxygen clusterings in addition to oxidized and graphitic phases during the low-temperature thermal annealing process, which could be further used for biomolecule bonding. By harnessing this property of GO, we created a bio-interface with patterned structures with a common laboratory hot plate that could tune cellular behavior by physical contact. Due to the regional distribution of oxygen clustering at the interface, we refer to it as patterned annealed graphene oxide (paGO). In addition, since the paGO was a heterogeneous interface and bonded biomolecules to varying degrees, arginine-glycine-aspartic acid (RGD) was modified on it and successfully regulated cellular-directed growth and migration. Finally, we investigated the FRET phenomenon of this heterogeneous interface and found that it has potential as a biosensor. The paGO interface has the advantages of easy regulation and fabrication, and the one-step thermal reduction method is suitable for biological applications. We believe that this low-temperature thermal annealing method would make GO interfaces more accessible, especially for the development of nano-interfacial modifications for biological applications, revealing its potential for biomedical applications.


Asunto(s)
Movimiento Celular , Grafito , Grafito/química , Movimiento Celular/efectos de los fármacos , Humanos , Oligopéptidos/química , Temperatura , Propiedades de Superficie , Animales , Tamaño de la Partícula
10.
J Control Release ; 374: 127-139, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39122216

RESUMEN

The immunosuppressive tumor microenvironment (TME) in solid tumors often impedes the efficacy of immunotherapy. Bacterial outer membrane vesicles (OMVs), as a promising cancer vaccine that can potently stimulate immune responses, have garnered interest as a potential platform for cancer therapy. However, the low yield of OMVs limits their utilization. To address this limitation, we developed a novel approach to synthesize OMV-like multifunctional synthetic bacterial vesicles (SBVs) by pretreating bacteria with ampicillin and lysing them through sonication. Compared to OMVs, the yield of SBVs increased by 40 times. Additionally, the unique synthesis process of SBVs allows for the encapsulation of bacterial intracellular contents, endowing SBVs with the capability of delivering catalase (CAT) for tumor hypoxia relief and activating the host cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway. To overcome the toxicity of lipopolysaccharide (LPS) on the SBVs surface, we decorated SBVs with a biocompatible polydopamine (PDA) shell, which allowed TME reprogramming using SBVs to be conducted without adverse side effects. Additionally, the photosensitizer indocyanine green (ICG) was loaded into the PDA shell to induce immunogenic cell death and further improve the efficacy of immunotherapy. In summary, the SBVs-based therapeutic platform SBV@PDA/ICG (SBV@P/I) can synergistically elicit safe and potent tumor-specific antitumor responses through combined immunotherapy and phototherapy.


Asunto(s)
Inmunoterapia , Verde de Indocianina , Microambiente Tumoral , Inmunoterapia/métodos , Animales , Verde de Indocianina/administración & dosificación , Membrana Externa Bacteriana , Línea Celular Tumoral , Ratones Endogámicos C57BL , Fármacos Fotosensibilizantes/administración & dosificación , Femenino , Neoplasias/terapia , Neoplasias/inmunología , Ratones , Humanos , Catalasa/administración & dosificación
11.
Curr Genomics ; 25(3): 226-235, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-39086996

RESUMEN

Introduction: Nicotine degradation is a new strategy to block nicotine-induced pathology. The potential of human microbiota to degrade nicotine has not been explored. Aims: This study aimed to uncover the genomic potentials of human microbiota to degrade nicotine. Methods: To address this issue, we performed a systematic annotation of Nicotine-Degrading Enzymes (NDEs) from genomes and metagenomes of human microbiota. A total of 26,295 genomes and 1,596 metagenomes for human microbiota were downloaded from public databases and five types of NDEs were annotated with a custom pipeline. We found 959 NdhB, 785 NdhL, 987 NicX, three NicA1, and three NicA2 homologs. Results: Genomic classification revealed that six phylum-level taxa, including Proteobacteria, Firmicutes, Firmicutes_A, Bacteroidota, Actinobacteriota, and Chloroflexota, can produce NDEs, with Proteobacteria encoding all five types of NDEs studied. Analysis of NicX prevalence revealed differences among body sites. NicX homologs were found in gut and oral samples with a high prevalence but not found in lung samples. NicX was found in samples from both smokers and non-smokers, though the prevalence might be different. Conclusion: This study represents the first systematic investigation of NDEs from the human microbiota, providing new insights into the physiology and ecological functions of human microbiota and shedding new light on the development of nicotine-degrading probiotics for the treatment of smoking-related diseases.

12.
Small ; : e2403560, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39212623

RESUMEN

Drug toxicity assays using conventional 2D static cultures and animal studies have limitations preventing the translation of potential drugs to the clinic. The recent development of organs-on-a-chip platforms provides promising alternatives for drug toxicity/screening assays. However, most studies conducted with these platforms only utilize single endpoint results, which do not provide real-time/ near real-time information. Here, a versatile technology is presented that integrates a 3D liver-on-a-chip with a label-free photonic crystal-total internal reflection (PC-TIR) biosensor for rapid and continuous monitoring of the status of cells. This technology can detect drug-induced liver toxicity by continuously monitoring the secretion rates and levels of albumin and glutathione S-transferase α (GST-α) of a 3D liver on-a-chip model treated with Doxorubicin. The PC-TIR biosensor is based on a one-step antibody functionalization with high specificity and a detection range of 21.7 ng mL-1 to 7.83 x 103 ng mL-1 for albumin and 2.20 ng mL-1 to 7.94 x 102 ng mL-1 for GST-α. This approach provides critical advantages for the early detection of drug toxicity and improved temporal resolution to capture transient drug effects. The proposed proof-of-concept study introduces a scalable and efficient plug-in solution for organ-on-a-chip technologies, advancing drug development and in vitro testing methods by enabling timely and accurate toxicity assessments.

13.
J Food Sci ; 89(9): 5576-5593, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39150698

RESUMEN

Roasting is essential for developing the characteristic aroma of flaxseed oil (FSO), yet its impact on oil quality remains underexplored. This study employed headspace-gas chromatography-mass spectrometry coupled with multivariate analysis to elucidate the dynamic changes in volatile compounds and quality characteristics of FSO subjected to varying roasting temperatures. Our findings revealed that seven key aroma compounds, identified through the variable importance in the projection scores of partial least square-discrimination analysis models and relative aroma activity value, served as molecular markers indicative of distinct roasting temperatures. These compounds included 2,5-dimethylpyrazine, 2-pentylfuran, (E)-2-pentenal, 2-ethyl-3,6-dimethylpyrazine, heptanal, octanal, and 2-hexenal. Notably, roasting at 200°C was found to enhance oil stability and antioxidant capacity, with phenolic compounds and Maillard reaction products playing synergistic roles in bolstering these qualities. Network analysis further uncovered significant correlations between these key aroma compounds and quality characteristics, offering novel perspectives for assessing FSO quality under diverse roasting conditions. This research not only enriched our understanding of the roasting process's impact on FSO but also provided valuable guidance for the optimization of industrial roasting practices. This study would provide important practical applications in aroma regulation and process optimization of flaxseed oil. .


Asunto(s)
Culinaria , Lino , Cromatografía de Gases y Espectrometría de Masas , Calor , Aceite de Linaza , Odorantes , Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/análisis , Lino/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Odorantes/análisis , Culinaria/métodos , Antioxidantes/análisis , Reacción de Maillard , Aldehídos/análisis , Fenoles/análisis , Manipulación de Alimentos/métodos
14.
Pestic Biochem Physiol ; 203: 106025, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39084764

RESUMEN

Peanut web blotch (PWB) caused by Phoma arachidicola, is one of the most serious foliar diseases of peanut. Although prochloraz is an active fungicide with broad anti-fungal spectrum, it has not been registered for the control of PWB in China. The activity of prochloraz against P. arachidicola and the risk of resistance to prochloraz in P. arachidicola are still unclear. In current study, the inhibitory activity of prochloraz against 96 P. arachidicola strains was determined with the average EC50 value of 1.2700 ± 0.7786 µg/mL. Prochloraz exhibited excellent protective and curative effect on detached peanut leaves, and the effect was obviously better than that of carbendazim and difenoconazole at the same concentration. After prochloraz treatment, the mycelium of P. arachidicola contorted, shrunk and ruptured, with shrinking of cell wall and membrane, enhanced cell membrane permeability, and reduced ergosterol content. Totally 80 prochloraz-resistant mutants were obtained by fungicide adaptation with the frequency of 6.7 × 10-3. All the selected 12 prochloraz-resistant mutants lost their resistance to prochloraz after 10 transfers on PDA plates. And these mutants exhibited decreased biological fitness in mycelial growth and pathogenicity. Moreover, there was positive cross-resistance between prochloraz and other demethylation inhibitor (DMI) fungicides, such as tebuconazole, triflumizole and difenoconazole, but no cross-resistance was found between prochloraz and other classes of fungicides, such as carbendazim, pydiflumetofen or fludioxonil. Overexpression of PaCYP51 and PaAtrB genes were detected in the resistant mutants. All the above results demonstrated that prochloraz has a great potential in management of PWB. The risk of P. arachidicola developing resistance to prochloraz is relatively low-to-medium. Overexpressing of PaCYP51 and PaAtrB might be linked to prochloraz resistance in P. arachidicola.


Asunto(s)
Arachis , Ascomicetos , Farmacorresistencia Fúngica , Fungicidas Industriales , Imidazoles , Enfermedades de las Plantas , Ascomicetos/efectos de los fármacos , Ascomicetos/genética , Fungicidas Industriales/farmacología , Imidazoles/farmacología , Farmacorresistencia Fúngica/genética , Enfermedades de las Plantas/microbiología , Arachis/microbiología , Medición de Riesgo , Carbamatos/farmacología , Mutación , Bencimidazoles
15.
Food Chem ; 460(Pt 1): 140525, 2024 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-39047472

RESUMEN

The determination of vitamin B6 (VB6) in food is of great significance due to its vital role in maintaining health and its necessity for ingestion through dietary sources. Therefore, based on ionic liquid-based yellow-emitting carbon dots (Y-CDs), a novel fluorescence-smartphone dual-mode method was first developed. The present method was applied to the detection of VB6 in milk. In the fluorescence method, the formation of complexes between VB6 and Y-CDs results in a significant decrease of the fluorescence intensity of Y-CDs. VB6 in milk samples was successfully determined according to this method, which exhibited a low detection limit (5 × 10-5 mg/mL) and excellent recoveries (98.80%-103.80%), demonstrating its feasibility in real sample analysis. In addition, the smartphone-based analysis method was established by researching the correlation between different VB6 concentrations and the (R + B) values of Y-CDs. When this method was applied, the detection process of VB6 was simplified. By combining the two methods, the possibility of incorrect analysis results can be effectively reduced, and the reliability of detection results can be improved through cross-validation of the two methods. Compared with traditional chromatography and electrochemical methods, the dual-mode method was more rapid, convenient, accurate, and suitable for the detection of VB6.


Asunto(s)
Carbono , Líquidos Iónicos , Leche , Puntos Cuánticos , Teléfono Inteligente , Vitamina B 6 , Leche/química , Animales , Carbono/química , Puntos Cuánticos/química , Líquidos Iónicos/química , Vitamina B 6/análisis , Fluorescencia , Límite de Detección , Espectrometría de Fluorescencia/métodos , Contaminación de Alimentos/análisis , Bovinos
16.
J Am Chem Soc ; 146(29): 20494-20499, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39001838

RESUMEN

The photochemistry of nitrous acid (HONO), encompassing dissociation into OH and NO as well as the reverse association reaction, plays a pivotal role in atmospheric chemistry. Here, we report the direct observation of nitrosyl-O-hydroxide (HOON) in the photochemistry of HONO, employing matrix-isolation IR and UV-vis spectroscopy. Despite a barrier of approximately 30 kJ/mol, HOON undergoes spontaneous rearrangement to the more stable HONO isomer through quantum mechanical tunneling, with a half-life of 28 min at 4 K. Kinetic isotope effects and instanton theory calculations reveal that the tunneling process involves the concerted motion of the NO moiety (65.2%) and the hydrogen atom (32.3%). Our findings underscore the significance of HOON as a key intermediate in the photolytic dissociation-association cycle of HONO at low temperatures.

17.
J Phys Chem A ; 128(28): 5525-5532, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-38961838

RESUMEN

Electronic-structure calculations combined with nonadiabatic trajectory surface-hopping (TSH) dynamic simulations were carried out on two alkenyl-substituted Criegee intermediates (CIs), i.e., propenyl-substituted CI (PCI) and 1-methyl-propenyl substituted CI (MPCI), in order to investigate the influence of the position and number of substituents on the photochemical process of CI in S1 states. It is found that they play critical roles in the reactivity, dominant product channel, and mechanism of the CIs. More specifically, introducing a methyl group on either C1 (α-C) or C3 (γ-C) position of a vinyl-substituted CI (VCI) skeleton facilitates the rotation of the C1═O1 bond and leads to the formation of a three-membered dioxirane ring; meanwhile, it evidently enhances the reactively of the S1-state molecule. Meanwhile, methyl substitution on the vinyl moiety [i.e., C2 (ß-C) and C3 (γ-C) positions] is beneficial for the rotation of the C2═C3 bond and thus facilitates the formation of the five-membered 1,2-dioxole ring, and the substitution on C2 site decreases the reactivity. The cosubstitution of C2 and C3 atoms by methyl groups well balances the features of VCI in the sense of high reactivity, consistently predominant channel, and possible dioxole side-product. The findings here not only deepen the knowledge on the photochemical processes of the CI but also inspire the rethinking of the "old" concept of substitution effect.

18.
J Phys Chem A ; 128(25): 4966-4975, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38869143

RESUMEN

Research on hypersonic vehicles has become increasingly important worldwide in recent years. However, accurately simulating the dynamics of the nonequilibrium high-temperature reactions that are in the hypersonic flow around the vehicles presents a significant challenge as a large number of states and transitions are accessible even for the smallest atom-diatom reaction systems. It is quite difficult, sometimes even impossible, to exhaustively investigate all relevant combinations or determine high-dimensional analytical representations for the state-to-state reaction probabilities. In this study, we used Gaussian process regression (GPR) to fit a model based on only 807 QCT data for training. The confidence interval of the GPR prediction and the Kullback-Leibler (KL) divergence were used to help minimize the sampling amount of data for fitting the converged GPR model. The model aims to predict the state-to-state integral cross section (ICS) of the O + O2 → 3O dissociation reaction under random initial conditions (Et, v, j). In total, it took almost a month to obtain this converged GPR model, but it took only a few seconds to predict the ICS value for any initial condition. For 330 initial conditions not included in the training set, the mean-square error (MSE) between the QCT-calculated ICSs and the GPR-predicted ones is only 0.08 Å2 and the R2 is 0.9986, indicating that the GPR model can replace the direct expensive QCT calculation with high accuracy. Finally, we calculated the equilibrium dissociation rate coefficients based on the StS ICS values predicted by the GPR model, and the results were in good agreement with available experimental and theoretical results. Thus, this study provides an effective and accurate approach to the extensive direct state-to-state reaction dynamic calculations.

19.
Chem Commun (Camb) ; 60(46): 5980-5983, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38769815

RESUMEN

Tuning the electrode-molecule interface stands at the heart of functional single-molecule devices. Herein, we report that the electrode-molecule interface of difluoro-substituted benzothiadiazole (FBTZ)-based single-molecule junctions can be modulated by the bias voltage. At low bias voltage (100 mV), the dative Au-N linkage is formed and at high bias voltage (600 mV), a covalent Au-C linkage is constructed. These junctions show distinct conductance. Interestingly, dominant charge carriers in Au-N- and Au-C-based junctions are different, as evidenced by dft calculations. These results provide a new strategy for regulating the electrode-molecule interface, which will advance the development of molecular electronics.

20.
Front Immunol ; 15: 1370647, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38694511

RESUMEN

Background: Hepatic Ischemia-Reperfusion Injury (HIRI) is a major complication in liver transplants and surgeries, significantly affecting postoperative outcomes. The role of mitophagy, essential for removing dysfunctional mitochondria and maintaining cellular balance, remains unclear in HIRI. Methods: To unravel the role of mitophagy-related genes (MRGs) in HIRI, we assembled a comprehensive dataset comprising 44 HIRI samples alongside 44 normal control samples from the Gene Expression Omnibus (GEO) database for this analysis. Using Random Forests and Support Vector Machines - Recursive Feature Elimination (SVM-RFE), we pinpointed eight pivotal genes and developed a logistic regression model based on these findings. Further, we employed consensus cluster analysis for classifying HIRI patients according to their MRG expression profiles and conducted weighted gene co-expression network analysis (WGCNA) to identify clusters of genes that exhibit high correlation within different modules. Additionally, we conducted single-cell RNA sequencing data analysis to explore insights into the behavior of MRGs within the HIRI. Results: We identified eight key genes (FUNDC1, VDAC1, MFN2, PINK1, CSNK2A2, ULK1, UBC, MAP1LC3B) with distinct expressions between HIRI and controls, confirmed by PCR validation. Our diagnostic model, based on these genes, accurately predicted HIRI outcomes. Analysis revealed a strong positive correlation of these genes with monocytic lineage and a negative correlation with B and T cells. HIRI patients were divided into three subclusters based on MRG profiles, with WGCNA uncovering highly correlated gene modules. Single-cell analysis identified two types of endothelial cells with different MRG scores, indicating their varied roles in HIRI. Conclusions: Our study highlights the critical role of MRGs in HIRI and the heterogeneity of endothelial cells. We identified the macrophage migration inhibitory factor (MIF) and cGAS-STING (GAS) pathways as regulators of mitophagy's impact on HIRI. These findings advance our understanding of mitophagy in HIRI and set the stage for future research and therapeutic developments.


Asunto(s)
Células Endoteliales , Hígado , Mitofagia , Daño por Reperfusión , Humanos , Mitofagia/genética , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo , Células Endoteliales/metabolismo , Hígado/metabolismo , Hígado/patología , Perfilación de la Expresión Génica , Masculino , Redes Reguladoras de Genes , Transcriptoma , Femenino
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