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1.
Chemistry ; : e202401576, 2024 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-38735852

RESUMEN

A yet-outstanding supramolecular chemistry challenge is isolation of novel varieties of stacked complexes with fine-tuned donor-acceptor bonding and optoelectronic properties, as herein reported for binary adducts comprising two different cyclic trinuclear complexes (CTC@CTC'). Most previous attempts focused only on 1-2 factors among metal/ligand/substituent combinations, resulting in heterobimetallic complexes. Instead, here we show that, when all 3 factors are carefully considered, a broadened variety of CTC@CTC' stacked pairs with intuitively-enhanced intertrimer coordinate-covalent bonding strength and ligand-ligand/metal-ligand dispersion are attained (dM-M' 2.868(2) Å; ΔE > 50 kcal/mol, an order of magnitude higher than aurophilic interactions). Significantly, CTC@CTC' pairs remain intact/strongly-bound even in solution (Keq 4.67×105 L/mol via NMR/UV-vis titrations), and the gas phase (mass spectrometry revealing molecular peaks for the entire CTC@CTC' units in sublimed samples), rather than simple co-crystal formation. Photo-/electro-luminescence studies unravel metal-centered phosphorescence useful for novel optoelectronic device concepts. This work manifests systematic design of supramolecular bonding and multi-faceted spectral properties of pure metal-organic macrometallacyclic donor/acceptor (inorganic/inorganic) stacks with remarkably-rich optoelectronic properties akin to well-established organic/organic and organic/inorganic analogues.

2.
Int J Biol Macromol ; 270(Pt 1): 132330, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38750840

RESUMEN

Developing flame retardant cotton fabrics (CF) is crucial for minimizing the harm caused by fires to people. To improve the flame retardancy of CF, this paper has synthesized a novel flame retardant called diboraspiro tetra phosphonate ammonium salt (N-PDBDN). The structure of N-PDBDN has been analyzed using FT-IR and NMR. Treating CF with N-PDBDN can increase the limiting oxygen index (LOI) to 36.2 % with a weight gain of 10.1 %. Moreover, even after undergoing 50 laundering cycles (LCs), the LOI remains at 27.1 %, indicating good flame retardancy and durability. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) show the presence of P and N elements on N-PDBDN treated CF, suggesting successful bonding between N-PDBDN and cellulose. Thermogravimetric analysis (TGA) results demonstrate that the addition of N-PDBDN significantly enhances the thermal stability and carbon formation ability of CF. Furthermore, cone calorimetry tests reveal reduced heat release rates (HRR), prolonged time to ignition (TTI), and 38 % lower total heat release (THR) in CF treated with N-PDBDN compared with pure cotton. Finally, a potential flame retardant mechanism involving N-PDBDN is proposed. These findings indicate that incorporating an ammonium phosphate group into CF can effectively improve the flame retardancy and durability.

3.
Chemistry ; : e202401122, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38749913

RESUMEN

Linkage chemistry is an essential aspect to covalent organic framework (COF) applications; it is highly desirable to precisely modulate electronic structure mediated directly by linkage for efficient COF-based photocatalytic hydrogen evolution, which however, remains substantially challenging. Herein, as a proof of concept, a collection of robust multicomponent pyrene-based COFs with abundant donor-acceptor (D-A) interactions has been judiciously designed and synthesized through molecularly engineering linkage for photogeneration of hydrogen. Controlled locking and conversion of linkage critically contribute to continuously regulating COFs' electronic structures further to optimize photocatalytic activities. Remarkably, the well-modulated optoelectronic properties turn on the average hydrogen evolution rate from zero to 15.67 mmol g-1 h-1 by the protonated quinoline-linked COF decorated with the trifluoromethyl group (TT-PQCOF-CF3). Using diversified spectroscopy and theoretical calculations, we show that multiple modifications toward linkage synergistically lead to the redistribution of charge on COFs with extended π-conjugation and reinforced D-A effect, making TT-PQCOF-CF3 a promising material with significantly boosted carrier separation and migration. This study provides important guidance for the design of high-performance COF photocatalysts based on the strategy of linkage-mediated electronic structure modulation in COFs.

4.
ACS Omega ; 9(14): 16055-16062, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38617649

RESUMEN

A specific matrix sensor that can operate at low temperatures and has a high sensing response is crucial for monitoring flammable VOC gases. In this study, a nanostructured SnO2 thin film was successfully produced using a suitable chemical deposition method, and its sensing properties were comprehensively analyzed. The SEM images revealed that the thin film of the nanostructured SnO2 is made up of two different sizes of broccoli-like structure nanoparticles. The sensor, which is based on this unique micronano structure, demonstrated a high sensing response (44), low operating temperature (200 °C), and fast response time (6s). Additionally, the nanostructured sensor exhibited excellent resistance to humidity interference and long-term stability. Moreover, DFT is employed to evaluate the electronic properties and to systematically explain the gas sensing mechanism of the nanostructured sensor based on the SnO2 thin film.

5.
Int J Biol Macromol ; 268(Pt 1): 131612, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38631572

RESUMEN

Cotton fabric is extensively utilized due to its numerous applications, but the flammability associated with cotton fabric poses potential security risks to individuals. A halogen-free efficient flame retardant named poly [(tetramethylcyclosiloxyl spirocyclic pentaerythritol)-piperazin phosphate] (PCPNTSi) was developed to consolidate the fire retardance of cotton fabrics. After PCPNTSi treatment, the limiting oxygen index (LOI) of cotton fabric with 30 % weight gain (CP3) was raised to 32.8 %. In the vertical flammability test (VFT), CP3 has self-extinguished performance with a char length of 8.7 cm. The heat release rate (HRR) of cotton fabric with 20 % weight gain (CP2) is 78.8 % lower than that of pure cotton fabric (CP0). In addition, the total smoke release (TSP) of CP2 is 41.7 % lower than that of CP0, indicating PCPNTSi gives cotton fabric a good capability to inhibit smoke release. Finally, the possible flame retardant mechanism was discussed by the data of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared spectroscopy (FT-IR) and thermogravimetric infrared spectroscopy (TG-IR). The results show that PCPNTSi is an intumescent flame retardant acting in both gas phase and solid phase.


Asunto(s)
Fibra de Algodón , Retardadores de Llama , Retardadores de Llama/análisis , Fibra de Algodón/análisis , Nitrógeno/química , Textiles/análisis
6.
Inorg Chem ; 63(16): 7206-7217, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38592922

RESUMEN

An understanding of how molecular structure influences the thermodynamics of H atom transfer is critical to designing efficient catalysts for reductive chemistries. Herein, we report experimental and theoretical investigations summarizing structure-function relationships of polyoxovanadate-alkoxides that influence bond dissociation free energies of hydroxide ligands located at the surface of the cluster. We evaluate the thermochemical descriptors of O-H bond strength for a series of clusters, namely [V6O13-x(OH)x(TRIOLR)2]-2 (x = 2, 4, 6; R = NO2, Me) and [V6O11-x(OMe)2(OH)x(TRIOLNO2)2]-2, via computational analysis and open circuit potential measurements. Our findings reveal that modifications to the TRIOL ligand (e.g., changing from the previously reported electron withdrawing nitro-backed ligand to the electron-donating methyl variant) have limited influence on the strength of surface O-H bonds as a result of near complete thermodynamic compensation in these systems (i.e., correlated changes in redox potential and cluster basicity). In contrast, changes in surface density of alkoxide ligands via direct alkoxylation of the polyoxovanadate-alkoxide surface result in measurable increases in bond dissociation free energies of surface O-H bonds for the mixed-valent derivatives. Our findings indicate that the extent of (de)localization of electron density across the cluster core has an impact on the bond dissociation free energies of surface O-H bonds across all oxidation states of the assembly.

7.
JACS Au ; 4(4): 1310-1314, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38665657

RESUMEN

In this report, we describe proton-coupled electron transfer (PCET) reactivity at the surface of the Keggin-type polyoxotungstate cluster [nBu4N]3[PWVI12O40] (PW12) in acetonitrile. Bond dissociation free energies (BDFEs) of the O-H groups generated upon reduction of PW12 in the presence of acid are determined through the construction of a potential-pKa diagram. The surface O-H bonds are found to be weak (BDFE(O-H)avg < 48 kcal mol-1), comparable to the BDFE of H2. This is consistent with the observed formation of H2 upon addition of a suitably strong organic acid, H2NPh2+ (pKa MeCN = 5.98), to the reduced form of the cluster. The one-electron reduced form of PW12 is isolated and used in conjunction with acid to realize the stoichiometric semihydrogenation of azobenzene via PCET from the surface of the reduced cluster.

8.
Adv Mater ; : e2403396, 2024 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-38613213

RESUMEN

Living cells actively interact biochemically and mechanically with the surrounding extracellular matrices (ECMs) and undergo dramatic morphological and dimensional transitions, concomitantly remodeling ECMs. However, there is no suitable method to quantitatively discuss the contribution of mechanical interactions in such mutually adaptive processes. Herein, a highly deformable "living" cellular scaffold is developed to evaluate overall mechanical energy transfer between cell and ECMs. It is based on the water-perfluorocarbon interface decorated with phospholipids bearing a cell-adhesive ligand and fluorescent tag. The bioinert nature of the phospholipid membranes prevents the formation of solid-like protein nanofilms at the fluid interface, enabling to visualize and quantify cellular mechanical work against the ultimately adaptive model ECM. A new cellular wetting regime is identified, wherein interface deformation proceeds to cell flattening, followed by its eventual restoration. The cellular mechanical work during this adaptive wetting process is one order of magnitude higher than those reported with conventional elastic platforms. The behavior of viscous liquid drops at the air-water interface can simulate cellular adaptive wetting, suggesting that overall viscoelasticity of the cell body predominates the emergent wetting regime and regulates mechanical output. Cellular-force-driven high-energy states on the adaptive platform can be useful for cell fate manipulation.

9.
J Agric Food Chem ; 72(10): 5176-5184, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38417018

RESUMEN

Microbial degradation is a highly efficient and reliable approach for mitigating the contamination of sulfonylurea herbicides, such as chlorimuron-ethyl, in soil and water. In this study, we aimed to assess whether Kj-mhpC plays a pivotal role in the degradation of chlorimuron-ethyl. Kj-mhpC enzyme purified via prokaryotic expression exhibited the highest catalytic activity for chlorimuron-ethyl at 35 °C and pH 7. Bioinformatic analysis and three-dimensional homologous modeling of Kj-mhpC were conducted. Additionally, the presence of Mg+ and Cu2+ ions partially inhibited but Pb2+ ions completely inhibited the enzymatic activity of Kj-mhpC. LC/MS revealed that Kj-mhpC hydrolyzes the ester bond of chlorimuron-ethyl, resulting in the formation of 2-(4-chloro-6-methoxypyrimidine-2-amidoformamidesulfonyl) benzoic acid. Furthermore, the point mutation of serine at position 67 (Ser67) confirmed that it is the key amino acid at the active site for degrading chlorimuron-ethyl. This study enhanced the understanding of how chlorimuron-ethyl is degraded by microorganisms and provided a reference for bioremediation of the environment polluted with chlorimuron-ethyl.


Asunto(s)
Herbicidas , Pirimidinas , Contaminantes del Suelo , Klebsiella/genética , Klebsiella/metabolismo , Esterificación , Contaminantes del Suelo/metabolismo , Herbicidas/metabolismo , Compuestos de Sulfonilurea/metabolismo , Iones
10.
Development ; 151(4)2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38265146

RESUMEN

Lysosomes are intracellular organelles responsible for degrading diverse macromolecules delivered from several pathways, including the endo-lysosomal and autophagic pathways. Recent reports have suggested that lysosomes are essential for regulating neural stem cells in developing, adult and aged brains. However, the activity of these lysosomes has yet to be monitored in these brain tissues. Here, we report the development of a new probe to measure lysosomal protein degradation in brain tissue by immunostaining. Our results indicate that lysosomal protein degradation fluctuates in neural stem cells of the hippocampal dentate gyrus, depending on age and brain disorders. Neural stem cells increase their lysosomal activity during hippocampal development in the dentate gyrus, but aging and aging-related disease reduce lysosomal activity. In addition, physical exercise increases lysosomal activity in neural stem cells and astrocytes in the dentate gyrus. We therefore propose that three different stages of lysosomal activity exist: the state of increase during development, the stable state during adulthood and the state of reduction due to damage caused by either age or disease.


Asunto(s)
Giro Dentado , Células-Madre Neurales , Animales , Ratones , Giro Dentado/metabolismo , Proteolisis , Células-Madre Neurales/metabolismo , Astrocitos/metabolismo , Lisosomas/metabolismo
11.
Chemosphere ; 351: 141178, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38218236

RESUMEN

Excessive or inappropriate applications of imazethapyr cause severe ecological deteriorations and health risks in human. A novel bacterial strain, i.e., Bacillus marcorestinctum YN1, was isolated to efficiently degrade imazethapyr, with the degradation pathways and intermediates predicted. Protein mass spectrometry analysis identified enzymes in strain YN1 potentially involved in imazethapyr biodegradation, including methylenetetrahydrofolate dehydrogenase, carbon-nitrogen family hydrolase, heme degrading monooxygenase, and cytochrome P450. The strain YN1 was further immobilized with biochar (BC600) prepared from mushroom waste (i.e., spent mushroom substrate) by pyrolysis at 600 °C to evaluate its degrading characteristics of imazethapyr. Scanning electron microscope observation showed that strain YN1 was adsorbed in the rich pore structure of BC600 and the adsorption efficiency reached the maximum level of 88.02% in 6 h. Both energy dispersive X-ray and Fourier transform infrared spectroscopy analyses showed that BC600 contained many elements and functional groups. The results of liquid chromatography showed that biochar-immobilized strain YN1 (IBC-YN1) improved the degradation rate of imazethapyr from 79.2% to 87.4%. The degradation rate of imazethapyr by IBC-YN1 could still reach 81.0% in the third recycle, while the bacterial survival rate was 67.73% after 180 d storage at 4 °C. The treatment of IBC-YN1 significantly shortened the half-life of imazethapyr in non-sterilized soil from 35.51 to 11.36 d, and the vegetative growth of imazethapyr sensitive crop plant (i.e., Cucumis sativus L.) was significantly increased in soil remediated, showing that the inhibition rate of root length and fresh weight were decreased by 12.45% and 38.49% respectively. This study exhanced our understanding of microbial catabolism of imazethapyr, and provided a potential in situ remediation strategy for improving the soil environment polluted by imazethapyr.


Asunto(s)
Bacillus , Carbón Orgánico , Herbicidas , Ácidos Nicotínicos , Contaminantes del Suelo , Humanos , Herbicidas/análisis , Suelo/química , Biodegradación Ambiental , Bacterias/metabolismo , Contaminantes del Suelo/análisis
12.
Small ; : e2310414, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38294968

RESUMEN

As opposed to natural photosynthesis, a significant challenge in a semiconductor-based photocatalyst is the limited hole extraction efficiency, which adversely affects solar-to-fuel efficiency. Recent studies have demonstrated that photocatalysts featuring spatially isolated dual catalytic oxidation/reduction sites can yield enhanced hole extraction efficiencies. However, the decay dynamics of excited states in such photocatalysts have not been explored. Here a ternary barbell-shaped CdS/MoS2 /Cu2 S heterostructure is prepared, comprising CdS nanorods (NRs) interfaced with MoS2 nanosheets at both ends and Cu2 S nanoparticles on the sidewall. By using transient absorption (TA) spectra, highly efficient charge separation within the CdS/MoS2 /Cu2 S heterostructure are identified. This is achieved through directed electron transfer to the MoS2 tips at a rate constant of >8.3 × 109 s-1 and rapid hole transfer to the Cu2 S nanoparticles on the sidewall at a rate of >6.1 × 1010 s-1 , leading to an exceptional overall charge transfer constant of 2.3 × 1011 s-1 in CdS/MoS2 /Cu2 S. The enhanced hole transfer efficiency results in a remarkably prolonged charge-separated state, facilitating efficient electron accumulation within the MoS2 tips. Consequently, the ternary CdS/MoS2 /Cu2 S heterostructure demonstrates a 22-fold enhancement in visible-light-driven H2 generation compare to pure CdS nanorods. This work highlights the significance of efficient hole extraction in enhancing the solar-to-H2 performance of semiconductor-based heterostructure.

13.
Int J Biol Macromol ; 260(Pt 1): 129497, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38232884

RESUMEN

A new synergistic flame retardant named Bisiminopropyl trimethoxysilane-1,3,5-triazine-O-bicyclic pentaerythritol phosphate (BTPODE) was synthesized, which is a type of Si/P/N flame retardant. This was accomplished by grafting aminopropyl trimethoxysilane and bicyclic pentaerythritol phosphate onto a triazine ring structure, serving as an intermediate. The structure of BTPODE was determined using nuclear magnetic resonance (1H NMR, 13C NMR, and 31P NMR) and Fourier transform infrared spectroscopy (FT-IR). SEM was used to detect the surface morphology of cotton fabrics, which suggested that BTPODE had been resoundingly stick to cotton fabrics. The flame retardant properties of cotton fabrics were evaluated by measuring the limiting oxygen index (LOI) and conducting vertical flammability experiments. Cotton fabrics with a weight gain of 20.73 % achieved an LOI value of 32.5 %. Thermogravimetric (TG) experiments demonstrated the samples' good thermostability. Furthermore, under nitrogen conditions, the char residue of cotton fabric with a weight gain of 20.73 % was 36.85 %. The cone calorimetry test (CONE) showed a significant reduction in the TSP value, indicating a certain level of smoke suppression performance. Finally, based on the obtained experimental results, the fire-retardant mechanism principle of the flame retardant was deduced.


Asunto(s)
Retardadores de Llama , Glicoles de Propileno , Silanos , Humanos , Triazinas/química , Espectroscopía Infrarroja por Transformada de Fourier , Fosfatos , Aumento de Peso
14.
Cell Mol Immunol ; 21(1): 19-32, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38082147

RESUMEN

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown. Using a Pseudomonas aeruginosa-induced pneumonia model, we reported that IL-10-producing B cells (IL-10+ B cells) play a key role in spontaneously resolving infection-mediated inflammation. Accumulated cytosolic reactive oxygen species (ROS) during inflammation were shown to drive IL-10+ B-cell generation by remodeling one-carbon metabolism. Depletion of the enzyme serine hydroxymethyltransferase 1 (Shmt1) led to inadequate one-carbon metabolism and decreased IL-10+ B-cell production. Furthermore, increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine (SAM), altering histone H3 lysine 4 methylation (H3K4me) at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells. Therefore, the one-carbon metabolism-associated compound ethacrynic acid (EA) was screened and found to potentially treat infectious pneumonia by boosting IL-10+ B-cell generation. Overall, these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.


Asunto(s)
Interleucina-10 , Neumonía , Humanos , Interleucina-10/metabolismo , Especies Reactivas de Oxígeno , S-Adenosilmetionina/metabolismo , Estrés Oxidativo , Inflamación , Carbono/metabolismo
15.
Apoptosis ; 29(1-2): 243-266, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37670104

RESUMEN

A particular GTPase-activating protein called RACGAP1 is involved in apoptosis, proliferation, invasion, metastasis, and drug resistance in a variety of malignancies. Nevertheless, the role of RACGAP1 in pan-cancer was less studied, and its value of the expression and prognostic of nasopharyngeal carcinoma (NPC) has not been explored. Hence, the goal of this study was to investigate the oncogenic and immunological roles of RACGAP1 in various cancers and its potential value in NPC. We comprehensively analyzed RACGAP1 expression, prognostic value, function, methylation levels, relationship with immune cells, immune infiltration, and immunotherapy response in pan-cancer utilizing multiple databases. The results discovered that RACGAP1 expression was elevated in most cancers and suggested poor prognosis, which could be related to the involvement of RACGAP1 in various cancer-related pathways such as the cell cycle and correlated with RACGAP1 methylation levels, immune cell infiltration and reaction to immunotherapy, and chemoresistance. RACGAP1 could inhibit anti-tumor immunity and immunotherapy responses by fostering immune cell infiltration and cytotoxic T lymphocyte dysfunction. Significantly, we validated that RACGAP1 mRNA and protein were highly expressed in NPC. The Gene Expression Omnibus database revealed that elevated RACGAP1 expression was associated with shorter PFS in patients with NPC, and RACGAP1 potentially influenced cell cycle progression, DNA replication, metabolism, and immune-related pathways, resulting in the recurrence and metastasis of NPC. This study indicated that RACGAP1 could be a potential biomarker in pan-cancer and NPC.


Asunto(s)
Biomarcadores de Tumor , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Apoptosis/genética , Proteínas Activadoras de GTPasa/genética , Proteínas Activadoras de GTPasa/metabolismo , Neoplasias Nasofaríngeas/genética
16.
Int J Biol Macromol ; 256(Pt 1): 128457, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38016602

RESUMEN

In response to the new concept of green sustainability, it is necessary to expand the functionality of bio-based natural fibers (such as cotton fabrics) to replace fabrics made from fossil fuels. One potential way of achieving this is through the use of phosphorus, boron and nitrogen based organic flame retardants. This article designs a special flame retardant system with high efficiency, high durability, and enhanced fabric strength. An "H" shaped flame retardant (TBSA) is synthesized using hydroxyethyl methylene phosphate, pentaerythritol diborate, and cyanuric chloride. After simple treatment, flame retardant fabric (TBSA/Cotton) is obtained, with a LOI value of 48.8 %. Self extinguishing is completing in the vertical flame test. The high FR efficiency reflects the progressiveness of multi flame retardant elements. It is worth noting that TBSA/Cotton exhibits excellent durability and improves the strength of the fabric. This is attributed to the covalent bonding between the "H" type flame retardant and multiple cellulose molecules, which compensates for the cracks and holes at the submicroscopic scale of natural cellulose and weakens the molecular slip effect. The research results of this article provide a good opportunity for the development of biomass cellulose flame retardant materials.


Asunto(s)
Retardadores de Llama , Textiles , Hidrógeno , Protones , Celulosa
17.
Heliyon ; 9(11): e21489, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38027986

RESUMEN

The Covid-19 pandemic has dramatically changed how information is shared and processed worldwide. The COVID-19 pandemic has profoundly affected the globalization of information, causing shifts in communication, information dissemination, and technology. This paper investigates the impact of pandemics-related uncertainty on the index of de facto informational globalization (the measure based on high-technology exports, international patents, and used internet bandwidth). The paper uses the panel dataset of 18 Central and Eastern European (CEE) countries from 1990 to 2020. The results indicate that pandemics-related uncertainty negatively affects the informational globalization level in the CEE economies. The findings are robust in utilizing different estimation techniques and considering NATO member CEE countries.

18.
RSC Adv ; 13(48): 33911-33917, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-38020029

RESUMEN

The investigation of the properties of aggregate materials is highly interesting because the process of aggregation can result in the disappearance of original properties and the emergence of new ones. Here, a novel fluorescent material (TPEIP), which synergistically combines aggregation-induced emission (AIE) and aggregation caused quenching (ACQ) moieties, was first synthesized by the cyclization reaction of 2,3-diamino-phenazine with 4-tetraphenylenthenealdehyde. We controlled the degree of aggregation of TPEIP to shed light on the impact of the aggregation on the excited state dynamics. TPEIP aggregation realized control over the Intersystem Crossing (ISC) rates and, in turn, the suppression of triplet excited states in MeOH, EtOH or via the simple addition of water to TPEIP solutions in DMSO. From global target analysis, the time scale was 966.2 ps for ISC for TPEIP in DMSO, but it was 860 ps in the case of TPEIP solutions featuring 5% water. The dynamics of TPEIP excited states undergo significant changes as the degree of aggregation increases. Notably, the lifetime of singlet excited states decreases, and there was a gradual diminishment in triplet states.

19.
Heliyon ; 9(10): e20801, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37867811

RESUMEN

Large-scale public health emergencies may exert significant adverse effects on market sentiment. This study utilizes interrupted time series analysis (ITSA) to explore the shift in Chinese investors' sentiment in response to the uncertainties due to the outbreak of the COVID-19 pandemic. The empirical findings demonstrate that COVID-19 had a notable impact on investor sentiment within China's stock markets. Before the outbreak of COVID-19, investor sentiment had been on an upward trend. However, since the onset of the pandemic, there has been a sustained decline in investor sentiment, aligning with the downward trend observed in China's stock markets. Interestingly, the immediate effect of the COVID-19 intervention was positive, briefly boosting investor sentiment. As of 2023, with the conclusion of the pandemic and the Chinese government's decision to end the zero COVID-19 policy, we anticipate resurgence in investor sentiment within China's stock markets.

20.
ACS Omega ; 8(37): 33658-33674, 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37744850

RESUMEN

Bromodomain and extra-terminal domain (BET) proteins play an important role in epigenetic regulation and are linked to several diseases; therefore, they are interesting targets. BET has two bromodomains: bromodomain 1 (BD1) and BD2. Selective targeting of BD1 or BD2 may produce different activities and greater effects than pan-BD inhibitors. However, the selective mechanism of the specific core must be studied at the atomic level. This study determined the effectiveness of pyrrolopyridone analogues to selectively inhibit BD2 using a pan-BD inhibitor (ABBV-075) and a selective-BD2 inhibitor (ABBV-744). Molecular dynamics simulations and calculations of binding free energies were used to systematically study the selectivity of BD2 inhibition by the pyrrolopyridone analogues. Overall, the pyrrolopyridone analogue inhibitors targeting BD2 interacted mainly with the following amino acid pairs between bromodomain-containing protein 4 (BRD4)-BD1 and BRD4-BD2 complexes: I146/V439, N140/N433, D144/H437, P82/P375, V87/V380, D88/D381, and Y139/Y432. The pyrrolopyridone analogues targeting BRD4-BD2 were divided into five regions based on selectivity mechanism. These results suggest that the R3 and R5 regions of pyrrolopyridone analogues can be modified to improve the selectivity between BRD4-BD1 and BRD4-BD2. The selectivity of BD2 inhibition by pyrrolopyridone analogues can be used to design novel BD2 inhibitors based on a pyrrolopyridone core.

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