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The ability to produce folded and functional proteins is a necessity for structural biology and many other biological sciences. This task is particularly challenging for numerous biomedically important targets in human cells, including membrane proteins and large macromolecular assemblies, hampering mechanistic studies and drug development efforts. Here we describe a method combining CRISPR-Cas gene editing and fluorescence-activated cell sorting to rapidly tag and purify endogenous proteins in HEK cells for structural characterization. We applied this approach to study the human proteasome from HEK cells and rapidly determined cryogenic electron microscopy structures of major proteasomal complexes, including a high-resolution structure of intact human PA28αß-20S. Our structures reveal that PA28 with a subunit stoichiometry of 3α/4ß engages tightly with the 20S proteasome. Addition of a hydrophilic peptide shows that polypeptides entering through PA28 are held in the antechamber of 20S prior to degradation in the proteolytic chamber. This study provides critical insights into an important proteasome complex and demonstrates key methodologies for the tagging of proteins from endogenous sources.
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Citometría de Flujo , Edición Génica , Proteínas Musculares , Complejo de la Endopetidasa Proteasomal , Sistemas CRISPR-Cas , Microscopía por Crioelectrón , Citometría de Flujo/métodos , Edición Génica/métodos , Células HEK293 , Humanos , Proteínas Musculares/química , Proteínas Musculares/genética , Proteínas Musculares/aislamiento & purificación , Complejo de la Endopetidasa Proteasomal/química , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/aislamiento & purificación , ProteolisisRESUMEN
To better understand the pathogenesis of acute type A aortic dissection, high-sensitivity liquid chromatography-tandem mass spectrometry/mass spectrometry (LC-MS/MS)-based proteomics and phosphoproteomics approaches were used to identify differential proteins. Heat shock protein family B (small) member 6 (HSPB6) in aortic dissection was significantly reduced in human and mouse aortic dissection samples by real-time PCR, western blotting, and immunohistochemical staining techniques. Using an HSPB6-knockout mouse, we investigated the potential role of HSPB6 in ß-aminopropionitrile monofumarate-induced aortic dissection. We found increased mortality and increased probability of ascending aortic dissection after HSPB6 knockout compared with wild-type mice. Mechanistically, our data suggest that HSPB6 deletion promoted vascular smooth muscle cell apoptosis. More importantly, HSPB6 deletion attenuated cofilin activity, leading to excessive smooth muscle cell stiffness and eventually resulting in the development of aortic dissection and rupture. Our data suggest that excessive stiffness of vascular smooth muscle cells caused by HSPB6 deficiency is a new pathogenetic mechanism leading to aortic dissection.
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Disección Aórtica , Espectrometría de Masas en Tándem , Ratones , Humanos , Animales , Cromatografía Liquida , Disección Aórtica/genética , Miocitos del Músculo Liso/metabolismo , Ratones Noqueados , Modelos Animales de Enfermedad , Proteínas del Choque Térmico HSP20/metabolismoRESUMEN
A novel dual-mode fluorometric and colorimetric sensing platform is reported for determining glutathione S-transferase (GST) by utilizing polyethyleneimine-capped silver nanoclusters (PEI-AgNCs) and cobalt-manganese oxide nanosheets (CoMn-ONSs) with oxidase-like activity. Abundant active oxygen species (O2â¢-) can be produced through the CoMn-ONSs interacting with dissolved oxygen. Afterward, the pink oxDPD was generated through the oxidation of colorless N,N-diethyl-p-phenylenediamine (DPD) by O2â¢-, and two absorption peaks at 510 and 551 nm could be observed. Simultaneously, oxDPD could quench the fluorescence of PEI-AgNCs at 504 nm via the inner filter effect (IFE). However, in the presence of glutathione (GSH), GSH prevents the oxidation of DPD due to the reducibility of GSH, leading to the absorbance decrease at 510 and 551 nm. Furthermore, the fluorescence at 504 nm was restored due to the quenching effect of oxDPD on decreased PEI-AgNCs. Under the catalysis of GST, GSH and1-chloro-2,4-dinitrobenzo (CDNB) conjugate to generate an adduct, initiating the occurrence of the oxidation of the chromogenic substrate DPD, thereby inducing a distinct colorimetric response again and the significant quenching of PEI-AgNCs. The detection limits for GST determination were 0.04 and 0.21 U/L for fluorometric and colorimetric modes, respectively. The sensing platform illustrated reliable applicability in detecting GST in real samples.
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Cobalto , Colorimetría , Glutatión Transferasa , Compuestos de Manganeso , Nanopartículas del Metal , Óxidos , Polietileneimina , Plata , Polietileneimina/química , Plata/química , Cobalto/química , Óxidos/química , Compuestos de Manganeso/química , Nanopartículas del Metal/química , Colorimetría/métodos , Glutatión Transferasa/metabolismo , Glutatión Transferasa/química , Límite de Detección , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Humanos , Glutatión/química , Oxidación-Reducción , Técnicas Biosensibles/métodos , Fenilendiaminas/química , Nanoestructuras/químicaRESUMEN
Photoanodes used in a water-splitting photoelectrochemical cell are almost always paired with an oxygen evolution catalyst (OEC) to efficiently utilize photon-generated holes for water oxidation because the surfaces of photoanodes are typically not catalytic for the water oxidation reaction. Suppressing electron-hole recombination at the photoanode/OEC interface is critical for the OEC to maximally utilize the holes reaching the interface for water oxidation. In order to explicitly demonstrate and investigate how the detailed features of the photoanode/OEC interface affect interfacial charge transfer and photocurrent generation for water oxidation, we prepared two BiVO4(010)/FeOOH photoanodes with different Bi:V ratios at the outermost layer of the BiVO4 interface (close to stoichiometric vs Bi-rich) while keeping all other factors in the bulk BiVO4 and FeOOH layers identical. The resulting two photoanodes show striking differences in the photocurrent onset potential and photocurrent density for water oxidation. The ambient pressure X-ray photoelectron spectroscopy results show that these two BiVO4(010)/FeOOH photoanodes show drastically different Fe2+:Fe3+ ratios in FeOOH both in the dark and under illumination with water, demonstrating the immense impact of the interfacial composition and structure on interfacial charge transfer. Using computational studies, we reveal the effect of the surface Bi:V ratio on the hydration of the BiVO4 surface and bonding with the FeOOH layer, which in turn affect the band alignments between BiVO4 and FeOOH. These results explain the atomic origin of the experimentally observed differences in electron and hole transfer and solar water oxidation performance of the two photoanodes having different interfacial compositions.
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Background: Computational fluid dynamics (CFD) is a new medical method combining medicine and science. The aim of this study is to summarize and analyze the application of CFD in adult aortic diseases. Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search in the PubMed, Cochrane Library and Chinese databases identified 47 highly relevant articles. Studies were included if they assessed biomechanical markers and their potential association with progression or rupture of aortic aneurysms or dissections. Results: There are no randomized controlled trials to examine the direct relationship between all biomechanical parameters and aortic disease progression or rupture. Wall stress and peak wall rupture risk can predict the risk of aortic aneurysm rupture using biomechanics, which is more accurate than the prediction based on "diameter" alone. Areas with lower time averaged wall shear stress (TAWSS) and higher oscillatory shear index (OSI) are at risk for further aortic expansion or dissection. Higher relative residence time (RRT) area can predict platelet activation and thrombosis. In addition, pressure, flow field and other indicators can also roughly predict the risk of aortic disease progression. Conclusions: Contemporary evidence suggests that CFD can provide additional hemodynamic parameters, which have the potential to predict the progression of aortic lesions, the effect of surgical intervention, and prognosis.
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Discovery of structure-property relationships in thin film alloys of complex metal oxides enabled by high-throughput materials synthesis and characterization facilities is demonstrated here with a case-study. Thin films of binary transition metal oxides (Ti-Zn) are prepared by pulsed laser deposition with continuously varying Ti:Zn ratio, creating combinatorial samples for exploration of the properties of this material family. The atomic structure and electronic properties are probed by spatially resolved techniques including x-ray absorption near edge structures (XANES) and x-ray fluorescence (XRF) at the Ti and Zn K-edge, x-ray diffraction, and spectroscopic ellipsometry. The observed properties as a function of Ti:Zn ratio are resolved into mixtures of five distinguishable phases by deploying multivariate curve resolution analysis on the XANES spectral series, under constraints set by results from the other characterization techniques. First-principles computations based on density function theory connect the observed properties of each distinct phase with structural and spectral characteristics of crystalline polymorphs of Ti-Zn oxide. Continuous tuning of the optical absorption edge as a function of Ti:Zn ratio, including the unusual observation of negative optical bowing, exemplifies a functional property of the film correlated to the phase evolution.
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A multi-signal aptasensor for thrombin determination is proposed based on catalytically active gold nanoparticles (AuNPs) and fluorescent silicon quantum dots (SiQDs). Yellow 4-Nitrophenol (4-NP) could be converted to colorless 4-Aminophenol (4-AP) by catalytically active aptamer-modified AuNPs (S1-AuNPs). The SiQDs emitted strong blue fluorescence at 455 nm at the excitation wavelength of 367 nm. When thrombin was absent, S1-AuNPs could catalytically reduce yellow 4-NP to colorless 4-AP. When thrombin was added, the aptamer could be transformed into a G-quadruplex structure, which masked the surface-active catalytic sites of AuNPs and restrained the reduction of 4-NP. Thus, the fluorescence of SiQDs was greatly quenched by 4-NP through the inner filter effect (IFE), and the solution color remained yellow. As the concentration of thrombin increased, the catalytic activity of S1-AuNPs decreased. The concentration of 4-NP that was converted to 4-AP declined and the unconverted 4-NP increased. In this process, the absorption peak of 4-NP at 400 nm increased while the fluorescence emission of SiQDs at 455 nm decreased. The linear ranges of the fluorometric and colorimetric aptasensor were 0.5-30 nM and 0.3-30 nM, respectively. The limits of detection (LOD) for the two modes were 0.15 nM and 0.13 nM. Furthermore, a portable sensing platform was constructed by combining the smartphone-based device with the software ImageJ for the determination of thrombin. With the advantages of cost-effectiveness, simplicity of operation and broad applicability, this aptasensor provided a new perspective for on-site determination of thrombin in the clinical field.
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Aptámeros de Nucleótidos , Nanopartículas del Metal , Puntos Cuánticos , Puntos Cuánticos/química , Oro/química , Trombina , Silicio , Nanopartículas del Metal/química , Aptámeros de Nucleótidos/química , ColorantesRESUMEN
Inspired by the architecture of single-atom catalysts, where the monodispersed metal atoms are widely distributed but stabilized by various coordination circumstances, the biomimetic design and synthesis of metalloporphyrin-containing nanocages have been demonstrated in this study. The nanocages were fabricated through a coordination-driven self-assembly process, and the Mn(III) porphyrin-based one was found to have exclusively peroxidase-like activity at pH 6.0 with neither oxidase nor catalase-like activity under the routine conditions. Benefiting from this, we demonstrated the wide applicability and convenient usage of an Mn(III)-containing supramolecular nanocage (Mn-PC) in the one-step detection of H2O2, sarcosine, and glucose through various oxidase-involved reactions, with a satisfactory detection limit and eligible specificity. Real samples including H2O2 in lens care solution, sarcosine in human urine, and glucose in human serum were also assayed, showing an adequate recovery rate. Such a specific activity originates from the super-consistent microstructure of each catalytic unit, which means that the active site of manganese porphyrin was "protected" by the confinement of the nanocage. This also helps to sustain the super long-term activity even after 545 days of storage. Furthermore, the intrinsic electronic structure of the Mn(III)-containing supramolecular nanocage endows the ability in electrochemical detection of H2O2 and glucose. Our smart design toward the supramolecular nanocages with a defined structure and quantity contributes to the construction of the ingenious sensing platform and has guiding significance for architectural design of nanozymes.
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Metaloporfirinas , Porfirinas , Catalasa , Dominio Catalítico , Glucosa/química , Humanos , Peróxido de Hidrógeno/química , Manganeso/química , Metaloporfirinas/química , Peroxidasa/metabolismo , Peroxidasas , Porfirinas/química , SarcosinaRESUMEN
Oral lichen planus (OLP) is a T cell-mediated, chronic inflammatory disease. CD4+ T-cell infiltration plays a crucial role in the pathogenesis of OLP. Fibroblasts are activated under pathological conditions and perform various functions. This study was designed to explore the immune activation and biological functions of OLP fibroblasts on CD4+ T cells. We detected the expression of fibroblast activation protein-alpha (FAP-α) in the oral tissues of patients with OLP and healthy controls using immunohistochemistry. Furthermore, expression of FAP-α and C-C motif chemokine ligand 5 (CCL5) in fibroblasts isolated from oral tissues of patients with OLP and healthy controls was assayed by quantitative PCR, Western blotting and enzyme-linked immunosorbent assay. Moreover, we assessed the effects of fibroblasts on CD4+ T-cell proliferation, apoptosis and migration using flow cytometry and Transwell assays. We found that FAP-α expression in the oral tissues of patients with OLP was significantly higher than that in healthy controls. FAP-α and CCL5 expression levels were significantly upregulated in OLP fibroblasts. Moreover, OLP fibroblasts promoted CD4+ T-cell proliferation and migration and inhibited CD4+ T cell apoptosis. In summary, our findings indicate that OLP fibroblasts are immunologically activated and induce CD4+ T-cell infiltration in OLP.
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Liquen Plano Oral , Linfocitos T CD4-Positivos/metabolismo , Quimiocina CCL5/metabolismo , Endopeptidasas , Humanos , Liquen Plano Oral/metabolismo , Proteínas de la Membrana , Linfocitos TRESUMEN
Iron-cobalt oxide nanosheets (FeCo-ONSs) were proved to have intrinsic peroxidase-like activity. Additionally, the peroxidase-like activity of FeCo-ONSs toward the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) was dramatically enhanced after heparin addition due to the stronger affinity toward TMB. Protamine combines with heparin, so the promotion of peroxidase-like activity of FeCo-ONSs with heparin was suppressed. With the addition of trypsin, protamine was hydrolyzed and the enhancement effect of catalytic activity of FeCo-ONSs was recovered. Based on above process, a sensitive colorimetric platform for trypsin activity determination was constructed through measuring the absorbance of produced oxTMB at 652 nm, providing a linear detection range of 5 to 500 ng/mL and a low detection limit of 2.8 ng/mL. The method was applied to trypsin determination in real samples (human urine sample and multienzyme tablet sample) with satisfactory results, illustrating the potential application of this biosensor.
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Colorimetría , Peroxidasa , Cobalto , Colorimetría/métodos , Heparina , Humanos , Hierro , Óxidos , Oxidorreductasas , Peroxidasas , Protaminas , TripsinaRESUMEN
Phillyrin is an effective lignan glycoside extracted from a traditional Chinese medicine Forsythia suspensa (Thunb.) Vahl (Oleaceae). It mainly exists in the roots, stems, leaves and fruits of the plant, with the highest content in the leaves. In terms of its medicinal application, there are a large number of experimental data proving its pharmacological effects in vitro and in animal models, such as anti-inflammatory, anti-obesity, anti-tumor, etc. Furthermore, pharmacokinetic experiments have also shown phillyrin's high effectiveness and low toxicity. Despite more than one thousand studies in the literature on phillyrin retrievable from Web of Science, PubMed, and CNKI, few reviews on its pharmacological activities have been presented conclusively. In this paper, we aimed to summarize the pharmacological and pharmacokinetic characteristics of phillyrin from the current literature, focusing on its anti-inflammatory, anti-aging, antiviral, antibacterial, hepatoprotective and anti-cancer effects, hoping to come up with new insights for its application as well as future studies.
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Forsythia , Animales , Antiinflamatorios/farmacología , Glucósidos/farmacología , Glicósidos , Extractos Vegetales/farmacologíaRESUMEN
In this work, a novel and sensitive fluorescence sensing system for alkaline phosphatase (ALP) was constructed using a bifunctional copper metal-organic framework (Cu@MOF) nanozyme, which had excellent oxidase-mimetic activity and fluorescence properties. Owing to the presence of 2-amino-1,4-benzenedicarboxylic acid (1,4-BDC-NH2) ligand, Cu@MOF displays excellent fluorescence performance at 444 nm. Additionally, Cu2+ endows the oxidase-like activity of Cu@MOF, which could trigger p-phenylenediamine (PPD) to be oxidized to a brown product (PPDox) and quench the photoluminescence of Cu@MOF through the inner filtration effect (IFE). As the preferential affinity of ATP for Cu2+, the catalytic activity of Cu@MOF was significantly reduced once ATP was added, thus PPD could not be oxidized and fluorescence was recovered. In the presence of ALP, ATP was hydrolyzed to adenosine and Pi, which allowed Cu@MOF to regain its catalytic activity and continued to catalyze the generation of PPDox. The fluorescence of Cu@MOF was therefore weakened once again. The ALP activity was directly proportional to the degree of decrease in fluorescence intensity. Thus, this novel fluorescence sensing strategy had a linear range of 0.5-60 U/L and the limit of detection was 0.14 U/L. The established sensing method could also be used to for ALP inhibitors screening, and achieved satisfactory results in determining the level of ALP activity in human serum.
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Fosfatasa Alcalina , Cobre , Estructuras Metalorgánicas , Espectrometría de Fluorescencia , Cobre/química , Fosfatasa Alcalina/antagonistas & inhibidores , Fosfatasa Alcalina/metabolismo , Fosfatasa Alcalina/química , Fosfatasa Alcalina/sangre , Estructuras Metalorgánicas/química , Humanos , Espectrometría de Fluorescencia/métodos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Fluorescencia , Límite de DetecciónRESUMEN
Herein, we synthesized a novel N-doped carbon layer encapsulated Fe/Co bimetallic nanoparticles (Fe/Co-NC), which exhibited superior oxidase-like activity due to the facilitation of electron penetration and the formation of metal-nitrogen active sites. Fe/Co-NC could catalyze the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) to blue oxTMB. Acetylcholinesterase (AChE) could catalyze the hydrolysis of thioacetylcholine to produce reducing thiocholine, which prevented TMB from oxidation. Thus, a portable hydrogel colorimetric sensor was developed for on-site and visual monitoring of AChE with the detection limit of 0.36 U L-1, and successfully applied to detect AChE in human erythrocyte samples. Furthermore, this platform was used to investigate the inhibition of triazophos on AChE activity.
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Bencidinas , Plaguicidas , Humanos , Plaguicidas/análisis , Oxidorreductasas/química , Acetilcolinesterasa , Colorimetría , HidrogelesRESUMEN
BACKGROUND: Due to that the higher activity of nanozymes would bring outstanding performance for the nanozyme-based biosensing strategies, great efforts have been made by researchers to improve the catalytic activity of nanozymes, and novel nanozymes with high catalytic activity are desired. Considering the crucial role in controlling blood glucose level, strategies like colorimetric and chemiluminescence to monitor α-glucosidase are developed. However, multi-mode detection with higher sensitivity was insufficient. Therefore, developing triple-mode detection method for α-glucosidase based on great performance nanozyme is of great importance. RESULTS: In this work, a novel nanozyme Cu-BCN was synthesized by loading Cu on boron doped carbon substrate g-C3N4 and applied to the colorimetric-fluorescent-smartphone triple-mode detection of α-glucosidase. In the presence of H2O2, Cu-BCN catalyzed the generation of 1O2 from H2O2, 1O2 subsequently oxidized TMB to blue colored oxTMB. In the presence of hydroquinone (HQ), the ROS produced from H2O2 was consumed, inhibiting the oxidation of TMB, which endows the possibility of colorimetric and visual on-site detection of HQ. Further, due to that the fluorescence of Mg-CQDs at 444 nm could be quenched by oxTMB, HQ could also be quantified through fluorescent mode. Since α-glucosidase could efficiently hydrolyze α-arbutin into HQ, the sensitive detection of α-glucosidase was realized. Further, colorimetric paper-based device (c-PAD) was fabricated for on-site α-glucosidase detection. The LODs for α-glucosidase via three modes were 2.20, 1.62 and 2.83 U/L respectively, high sensitivities were realized. SIGNIFICANCE: The nanozyme Cu-BCN possesses higher peroxidase-like activity by doping boron to the substrate than non-doped Cu-CN. The proposed triple-mode detection of α-glucosidase is more sensitive than most previous reports, and is reliable when applied to practical sample. Further, the smartphone-based colorimetric paper-based analytical device (c-PAD) made of simple materials could also detect α-glucosidase sensitively. The smartphone-based on-site detection provided a convenient, instrument-free and sensitive sensing method for α-glucosidase.
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Boro , Colorimetría , Cobre , Teléfono Inteligente , alfa-Glucosidasas , Colorimetría/métodos , Cobre/química , alfa-Glucosidasas/metabolismo , alfa-Glucosidasas/química , Boro/química , Compuestos de Nitrógeno/química , Límite de Detección , Técnicas Biosensibles/métodos , Colorantes Fluorescentes/química , Humanos , GrafitoRESUMEN
Captopril (CP) is commonly used as an active enzyme inhibitor for the treatment of coronary heart disease, hypertension and angina pectoris. The development of sensitive and efficient method for CP analysis is of great importance in biomedical research. Herein, we fabricated a sensitive and robust hydrogel-assisted paper-based sensor based on fluorescence UiO-66-NH2@ZIF-8 and Co, N-doped carbon nanozymes with oxidase-mimicking activity for accurate monitoring of captopril. The hydrogel-assisted paper-based sensor appeared a visible pink signal due to the catalytic oxidation of colorless N,N-diethyl-p-phenylenediamine (DPD) to oxDPD by Co, N-doped carbon-based nanozymes, and resulted in the fluorescence quenching of UiO-66-NH2@ZIF-8. In the presence of captopril, the oxidation of chromogenic substrate DPD by Co, N-doped nanozymes in the hydrogel-assisted paper-based sensor was hindered and accompanied by a change in the visible color, leading to recovery of the fluorescence of UiO-66-NH2@ZIF-8, and the change in the fluorescence color could also be observed. Therefore, the quantitative detection of captopril is achieved by taking a smartphone photograph and converting the image parameters into data information using ImageJ software. The portable hydrogel-assisted paper sensor provided sensitive detection of captopril in two modes based on visible color change as well as fluorescence color change with limits of detection of 0.45 µM and 0.47 µM, respectively. This hydrogel-assisted paper-based sensor has been successfully applied to the accurate monitoring of captopril in human serum, providing a potential avenue for in situ detection of captopril.
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Captopril , Hidrogeles , Papel , Captopril/análisis , Captopril/sangre , Captopril/química , Humanos , Hidrogeles/química , Estructuras Metalorgánicas/química , Fluorescencia , Límite de Detección , Espectrometría de Fluorescencia , Oxidación-ReducciónRESUMEN
Adding bio-based flame retardants to improve the flame retardancy of polymer materials without sacrificing other properties is a great challenge. Herein, a novel flame-retardant CS-DOPA was prepared from chitosan and 10-hydroxy-9,10-dihydro-9-oza-10-phosphaphenanthrene-10-oxide by acid-base neutralization reaction and fully characterized. The 4 wt% CS-DOPA modified EP showed good flame retardancy in both gaseous and condensed phase. The peak heat release rate, total smoke production, CO production, and smoke production rate of EP composites containing 4 wt% CS-DOPA were reduced by 55 %, 34 %, 45 %, and 46 %, respectively, to pass the UL-94 V-1 rating with a limiting oxygen index of 34.1 %. The CS-DOPA contributes to the formation of the condensed phase of the thermo-oxidation-resistant high-quality char layer with non-flammable other and phosphorus-containing free radicals released in the gas phase. In addition, EP/4CS-DOPA has good water resistance, mechanical properties, and transparency, with tensile and flexural strength improved by 12.7 % and 13.9 %, respectively, and still has high strength even after water treatment. The present work provides a green and facile strategy to use chitosan as a main raw material to manufacture EP materials with high performance.
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Quitosano , Retardadores de Llama , Resinas Epoxi , Gases , DihidroxifenilalaninaRESUMEN
Recent advances in superconducting qubit technology have led to significant progress in quantum computing, but the challenge of achieving a long coherence time remains. Despite the excellent lifetime performance that tantalum (Ta) based qubits have demonstrated to date, the majority of superconducting qubit systems, including Ta-based qubits, are generally believed to have uncontrolled surface oxidation as the primary source of the two-level system loss in two-dimensional transmon qubits. Therefore, atomic-scale insight into the surface oxidation process is needed to make progress toward a practical quantum processor. In this study, the surface oxidation mechanism of native Ta films and its potential impact on the lifetime of superconducting qubits were investigated using advanced scanning transmission electron microscopy (STEM) techniques combined with density functional theory calculations. The results suggest an atomistic model of the oxidized Ta(110) surface, showing that oxygen atoms tend to penetrate the Ta surface and accumulate between the two outermost Ta atomic planes; oxygen accumulation at the level exceeding a 1:1 O/Ta ratio drives disordering and, eventually, the formation of an amorphous Ta2O5 phase. In addition, we discuss how the formation of a noninsulating ordered TaO1-δ (δ < 0.1) suboxide layer could further contribute to the losses of superconducting qubits. Subsurface oxidation leads to charge redistribution and electric polarization, potentially causing quasiparticle loss and decreased current-carrying capacity, thus affecting superconducting qubit coherence. The findings enhance the comprehension of the realistic factors that might influence the performance of superconducting qubits, thus providing valuable guidance for the development of future quantum computing hardware.
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OBJECTIVES: The optimal core temperature for hypothermic circulatory arrest during aortic arch surgery remains contentious. This study aims to evaluate patient outcomes under various temperatures within a large single-center cohort. METHODS: Between 2010 and 2018, patients diagnosed with type A aortic dissection underwent total arch replacement at Fuwai Hospital were enrolled. They were categorized into four groups: deep hypothermia group, low-moderate hypothermia group, high-moderate hypothermia group, and mild hypothermia group. Clinical data were analyzed to ascertain differences between the groups. RESULTS: A total of 1310 patients were included in this cohort. Operative mortality stood at 6.9% (90/1310), with a higher incidence observed in the deep hypothermia group [29 (12.9%); 35 (6.9%); 21 (4.8%); 5 (3.4%); all adjusted P < 0.05]. Overall 10-year survival was 80.3%. Long-term outcomes did not significantly differ among the groups. Multivariable logistic analysis revealed a protective effect of higher core temperature on operative mortality (odds ratio 0.848, 95% confidence interval 0.766-0.939; P = 0.001). High-moderate hypothermia emerged as an independent protective factor for operative mortality (odds ratio 0.303, 95% confidence interval 0.126-0.727; P = 0.007). Multivariable Cox analysis did not detect an effect of hypothermic circulatory arrest on long-term survival (all P > 0.05). CONCLUSIONS: High-moderate hypothermia (24.1-28 °C) offers the most effective protection against surgical mortality and is therefore recommended. Different hypothermic circulatory arrest temperatures do not influence long-term survival or quality of life.
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Objective: To evaluate the efficacy of the fruits of the medicinal plant Forsythia suspensa (Thunb.) Vahl (FS), in treating inflammation-associated diseases through a meta-analysis of animal models, and also probe deeply into the signaling pathways underlying the progression of inflammation. Materials and methods: All data analyses were performed using Review Manager 5.3 and the results are presented as flow diagrams, risk-of-bias summaries, forest plots, and funnel plots. Summary estimates were calculated using a random- or fixed-effect model, depending on the value of I2. Results: Of the 710 records identified in the initial search, 11 were selected for the final meta-analysis. Each study extracted data from the model and treatment groups for analysis, and the results showed that FS alleviated the inflammatory cytokine levels in serum; oxidant indicator: reactive oxygen species; enzymes of liver function; endotoxin and regulatory cells in blood; and improved the antioxidant enzyme superoxide dismutase. Conclusion: FS effectively reversed the change in acute or chronic inflammation indicators in animal models, and the regulation of multiple channel proteins in inflammatory signaling pathways suggests that FS is a good potential drug for inflammatory disease drug therapy.