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BACKGROUND: Vesicle-mediated transport, vital for substance exchange and intercellular communication, is linked to tumor initiation and progression. This work was designed to study the role of vesicle-mediated transport-related genes (VMTRGs) in breast cancer (BC)prognosis. METHODS: Univariate Cox analysis was utilized to screen prognosis-related VMTRGs. BC samples underwent unsupervised clustering based on VMTRGs to analyze survival, clinical factors, and immune cell abundance across different subtypes. We constructed a risk model using univariate Cox and LASSO regression analysis, with validation conducted using GEO datasets. Subsequently, we performed tumor mutational burden analysis, and immune landscape analysis on both groups. Ultimately, we conducted immunophenoscore (IPS) scoring to forecast immunotherapy and performed drug sensitivity analysis. RESULTS: We identified 102 VMTRGs associated with BC prognosis. Using these 102 VMTRGs, BC patients were classified into 3 subtypes, with Cluster3 patients showing significantly better survival rates. We constructed a prognostic model for BC based on 12 VMTRGs that effectively predicted patient survival. Riskscore was an independent prognostic factor for BC patients. According to median risk score, high-risk group (HRG) had higher TMB values. The immune landscape of the HRG exhibited characteristics of cold tumor, with higher immune checkpoint expression levels and lower IPS scores, whereas Gemcitabine, Nilotinib, and Oxaliplatin were more suitable for treating low-risk group. CONCLUSION: We classified BC subtypes and built a prognostic model based on VMTRGs. The genes in the prognostic model may serve as potential targets for BC therapy.
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Neoplasias da Mama , Humanos , Feminino , Prognóstico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Transporte Biológico , Comunicação Celular , Transformação Celular Neoplásica , Microambiente TumoralRESUMO
A heavy layer of glycans forms a brush matrix bound to the outside of all the cells in our bodies; it is referred to as the "sugar forest" or glycocalyx. Beyond the increased appreciation of the glycocalyx over the past two decades, recent advances in engineering the glycocalyx on live cells have spurred the creation of cellular drugs and novel medical treatments. The development of new tools and techniques has empowered scientists to manipulate the structures and functions of cell-surface glycans on target cells and endow target cells with desired properties. Herein, we provide an overview of live-cell glycocalyx engineering strategies for controlling the cell-surface molecular repertory to suit therapeutic applications, even though the realm of this field remains young and largely unexplored.
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Glicocálix , Polissacarídeos , Glicocálix/química , Glicocálix/metabolismo , Membrana Celular/metabolismo , Polissacarídeos/químicaRESUMO
In this paper, the physicochemical properties, surface charge, and crystal defects of MIL-88A (Al) were controlled by adjusting the ratio of metal ligands and temperature in the synthetic system without the addition of surfactants. The adsorption properties of different crystals for Congo red (CR) were studied. Among them, MIL-88A (Al)-130 and MIL-88A (Al)-d have the best adsorption properties. The maximum adsorption capacities are 600.8 and 1167 mg · g-1, respectively. Compared with MIL-88A (Al)-130, the adsorption performance of MIL-88A (Al)-d was increased by 94.2%, and the adsorption rate was increased by about 4 times. It can be seen that increasing the proportion of metal ligands within a certain range will improve the adsorption capacity. The structure and morphology of the adsorbent were characterized by XRD, FTIR, SEM, EDS, TGA, BET, and zeta potential. The effects of time, temperature, pH, initial solution concentration, and dosage on CR adsorption properties were systematically discussed. The pseudo-second-order kinetic model and Langmuir isothermal model can well describe the adsorption process, which indicates that the adsorption process is a single-layer chemisorption occurring on a uniform surface. According to thermodynamics, this adsorption is an endothermic process. The mechanism of CR removal is proposed as the electrostatic attraction, hydrogen bond, metal coordination effect, π-π conjugation, crystal defect, and pore-filling effect. In addition, MIL-88A (Al)-d has good repeatability, indicating that it is a good material for treating anionic dye wastewater.
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Viral infection and replication are affected by host cell heterogeneity, but the mechanisms underlying the effects remain unclear. Using single-cell analysis, we investigated the effects of host cell heterogeneity, including cell size, inclusion, and cell cycle, on foot-and-mouth disease virus (FMDV) infection (acute and persistent infections) and replication. We detected various viral genome replication levels in FMDV-infected cells. Large cells and cells with a high number of inclusions generated more viral RNA copies and viral protein and a higher proportion of infectious cells than other cells. Additionally, we found that the viral titer was 10- to 100-fold higher in cells in G2/M than those in other cell cycle phases and identified a strong correlation between cell size, inclusion, and cell cycle heterogeneity, which all affected the infection and replication of FMDV. Furthermore, we demonstrated that host cell heterogeneity influenced the adsorption of FMDV due to differences in the levels of FMDV integrin receptors expression. Collectively, these results further our understanding of the evolution of a virus in a single host cell.IMPORTANCE It is important to understand how host cell heterogeneity affects viral infection and replication. Using single-cell analysis, we found that viral genome replication levels exhibited dramatic variability in foot-and-mouth disease virus (FMDV)-infected cells. We also found a strong correlation between heterogeneity in cell size, inclusion number, and cell cycle status and that all of these characteristics affect the infection and replication of FMDV. Moreover, we found that host cell heterogeneity influenced the viral adsorption as differences in the levels of FMDV integrin receptors' expression. This study provided new ideas for the studies of correlation between FMDV infection mechanisms and host cells.
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Tamanho Celular , Vírus da Febre Aftosa/fisiologia , Pontos de Checagem da Fase M do Ciclo Celular/fisiologia , Análise de Célula Única/métodos , Replicação Viral/fisiologia , Animais , Linhagem Celular , Cricetinae , Febre Aftosa/virologia , Vírus da Febre Aftosa/genética , Genoma Viral/genética , RNA Viral/genética , Carga Viral/fisiologiaRESUMO
The interferon-inducible dynamin-like GTPase myxovirus resistance protein A (MxA) exhibits activity against multiple viruses. However, its role in the life cycle of hepatitis C virus (HCV) is unclear, and the mechanisms underlying the anti-HCV activity of MxA require further investigation. In this study, we demonstrated that exogenous MxA expression in the Huh7 and Huh7.5.1 hepatoma cell lines significantly decreased the levels of HCV RNA and core proteins, whereas MxA knockdown exerted the opposite effect. MxA-mediated inhibition of HCV replication was found to involve the JAK-STAT pathway: STAT1 phosphorylation and the expression of IFN-stimulated genes (ISGs) such as guanylate-binding protein 1 and 2'-5'-oligoadenylate synthetase 1 were augmented by MxA overexpression and reduced by endogenous MxA silencing. Treatment with the JAK inhibitor ruxolitinib abrogated the MxA-mediated suppression of HCV replication and activation of the JAK-STAT pathway. Additionally, transfection with an MxA mutant with disrupted GTP-binding consensus motifs abrogated activation of the JAK-STAT pathway and resistance to HCV replication. This study shows that MxA inhibits HCV replication by activating the JAK-STAT signaling pathway through a mechanism involving its GTPase function.
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Hepatócitos/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Janus Quinases/imunologia , Proteínas de Resistência a Myxovirus/imunologia , Fator de Transcrição STAT1/imunologia , 2',5'-Oligoadenilato Sintetase/genética , 2',5'-Oligoadenilato Sintetase/imunologia , Linhagem Celular Tumoral , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/imunologia , Regulação da Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/virologia , Interações Hospedeiro-Patógeno/genética , Humanos , Janus Quinases/genética , Proteínas de Resistência a Myxovirus/antagonistas & inibidores , Proteínas de Resistência a Myxovirus/genética , Nitrilas , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT1/genética , Transdução de Sinais , Transgenes , Replicação ViralRESUMO
UNLABELLED: Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is essential for HCV genome replication and virion production and is involved in the regulation of multiple host signaling pathways. As a proline-rich protein, NS5A is capable of interacting with various host proteins containing Src homology 3 (SH3) domains. Previous studies have suggested that vinexin, a member of the sorbin homology (SoHo) adaptor family, might be a potential binding partner of NS5A by yeast two-hybrid screening. However, firm evidence for this interaction is lacking, and the significance of vinexin in the HCV life cycle remains unclear. In this study, we demonstrated that endogenously and exogenously expressed vinexin ß coimmunoprecipitated with NS5A derived from different HCV genotypes. Two residues, tryptophan (W307) and tyrosine (Y325), in the third SH3 domain of vinexin ß and conserved Pro-X-X-Pro-X-Arg motifs at the C terminus of NS5A were indispensable for the vinexin-NS5A interaction. Furthermore, downregulation of endogenous vinexin ß significantly suppressed NS5A hyperphosphorylation and decreased HCV replication, which could be rescued by expressing a vinexin ß short hairpin RNA-resistant mutant. We also found that vinexin ß modulated the hyperphosphorylation of NS5A in a casein kinase 1α-dependent on manner. Taken together, our findings suggest that vinexin ß modulates NS5A phosphorylation via its interaction with NS5A, thereby regulating HCV replication, implicating vinexin ß in the viral life cycle. IMPORTANCE: Hepatitis C virus (HCV) nonstructural protein NS5A is a phosphoprotein, and its phosphorylation states are usually modulated by host kinases and other viral nonstructural elements. Additionally, cellular factors containing Src homology 3 (SH3) domains have been reported to interact with proline-rich regions of NS5A. However, it is unclear whether there are any relationships between NS5A phosphorylation and the NS5A-SH3 interaction, and little is known about the significance of this interaction in the HCV life cycle. In this work, we demonstrate that vinexin ß modulates NS5A hyperphosphorylation through the NS5A-vinexin ß interaction. Hyperphosphorylated NS5A induced by vinexin ß is casein kinase 1α dependent and is also crucial for HCV propagation. Overall, our findings not only elucidate the relationships between NS5A phosphorylation and the NS5A-SH3 interaction but also shed new mechanistic insight on Flaviviridae NS5A (NS5) phosphorylation. We believe that our results may afford the potential to offer an antiviral therapeutic strategy.
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Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Hepacivirus/fisiologia , Interações Hospedeiro-Patógeno , Processamento de Proteína Pós-Traducional , Proteínas não Estruturais Virais/metabolismo , Replicação Viral , Linhagem Celular , Hepatócitos/virologia , Humanos , Imunoprecipitação , Proteínas Musculares , Fosforilação , Ligação Proteica , Mapeamento de Interação de Proteínas , Técnicas do Sistema de Duplo-HíbridoRESUMO
Background: Alzheimer's disease and related dementias (ADRD) are progressive conditions. Family caregivers of patients, especially those caring for patients with ADRD exhibiting behavioral and psychological symptoms of dementia (BPSD), undergo significant physical and mental changes during long-term care. While most researchers have focused on the specific needs of family caregivers, the comprehensive understanding of these needs is limited. In this study, Alderfer's existence, relatedness, and growth theory was used to develop an interview framework to systematically and comprehensively understand the needs of family caregivers of individuals with ADRD. Objective: The objective of this study was to understand family caregivers' needs in coping with BPSD in individuals with ADRD, aiming to alleviate caregivers' stress and promote their overall well-being. Methods: This study used a hermeneutic-phenomenological interview research design. Data were collected via remote conferences involving interviews with 17 participants selected via maximum variation sampling. The Colaizzi seven-step method was utilized, and the interview contents were analyzed using NVivo 12.0 software. Results: The needs of family caregivers in coping with the BPSD of individuals with ADRD could be summarized into three themes, namely existence needs, relatedness needs, and growth needs, and 10 sub-themes. Conclusions: The study findings provide new insights into the needs of family caregivers in coping with patients exhibiting BPSD. Family caregivers experience significant negative emotions, poor caregiving experiences, heavy caregiving burdens, and a desire for professional assistance and policy support.
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Adaptação Psicológica , Cuidadores , Demência , Humanos , Cuidadores/psicologia , Adaptação Psicológica/fisiologia , Feminino , Masculino , Demência/psicologia , Demência/enfermagem , Idoso , Pessoa de Meia-Idade , Hermenêutica , Estresse Psicológico/psicologia , Idoso de 80 Anos ou mais , Adulto , Família/psicologiaRESUMO
Tigecycline (TGC) is currently used to treat carbapenem-resistant Acinetobacter baumannii (CRAB) infections, while eravacycline (ERV), a new-generation tetracycline, holds promise as a novel therapeutic option for these infections. However, differences in resistance mechanism between ERV and TGC against A. baumannii remain unclear. This study sought to compare the characteristics and mechanisms of ERV and TGC resistance among clinical A. baumannii isolates. A total of 492 isolates, including 253 CRAB and 239 carbapenem-sensitive A. baumannii (CSAB) isolates, were collected from hospitalized patients in China. The MICs of ERV and TGC against A. baumannii were determined by broth microdilution. Genetic mutations and expressions of adeB, adeG, adeJ, adeS, adeL, and adeN in resistant strains were examined by PCR and qPCR, respectively. The in vitro recombination experiments were used to verify the resistance mechanism of ERV and TGC in A. baumannii. The MIC90 of ERV in CRAB and CSAB isolates were lower than those of TGC. A total of 24 strains resistant to ERV and/or TGC were categorized into three groups: only ERV-resistant (n = 2), both ERV- and TGC-resistant (n = 7), and only TGC-resistant (n = 15). ST208 (75%, n = 18) was a major clone that has disseminated in all three groups. The ISAba1 insertion in adeS was identified in 66.7% (6/9) of strains in the only ERV-resistant and both ERV- and TGC-resistant groups, while the ISAba1 insertion in adeN was found in 53.3% (8/15) of strains in the only TGC-resistant group. The adeABC and adeRS expressions were significantly increased in the only ERV-resistant and both ERV- and TGC-resistant groups, while the adeABC and adeIJK expressions were significantly increased and adeN was significantly decreased in the only TGC-resistant group. Expression of adeS with the ISAba1 insertion in ERV- and TGC-sensitive strains significantly increased the ERV and TGC MICs and upregulated adeABC and adeRS expressions. Complementation of the wildtype adeN in TGC-resistant strains with the ISAba1 insertion in adeN restored TGC sensitivity and significantly downregulated adeIJK expression. In conclusion, our data illustrates that ERV is more effective against A. baumannii clinical isolates than TGC. ERV resistance is correlated with the ISAba1 insertion in adeS, while TGC resistance is associated with the ISAba1 insertion in adeN or adeS in A. baumannii.
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In-depth comprehension and modulation of the electronic structure of the active metal sites is crucial to enhance their intrinsic activity of electrocatalytic oxygen evolution reaction (OER) toward anion exchange membrane water electrolyzers (AEMWEs). Here, we elaborate a series of amorphous metal oxide catalysts (FeCrOx, CoCrOx and NiCrOx) with high performance AEMWEs by high-valent chromium dopant. We discover that the positive effect of the transition from low to high valence of the Co site on the adsorption energy of the intermediate and the lower oxidation barrier is the key factor for its increased activity by synchrotron radiation in-situ techniques. Particularly, the CoCrOx anode catalyst achieves the high current density of 1.5 A cm-2 at 2.1 V and maintains for over 120 h with attenuation less than 4.9 mV h-1 in AEMWE testing. Such exceptional performance demonstrates a promising prospect for industrial application and providing general guidelines for the design of high-efficiency AEMWEs systems.
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Carbapenem-resistant Acinetobacter baumannii (CRAB) is resistant to almost all antibiotics. Eravacycline, a newer treatment option, has the potential to treat CRAB infections, however, the mechanism by which CRAB isolates develop resistance to eravacycline has yet to be clarified. This study sought to investigate the features and mechanisms of eravacycline heteroresistance among CRAB clinical isolates. A total of 287 isolates were collected in China from 2020 to 2022. The minimum inhibitory concentration (MIC) of eravacycline and other clinically available agents against A. baumannii were determined using broth microdilution. The frequency of eravacycline heteroresistance was determined by population analysis profiling (PAP). Mutations and expression levels of resistance genes in heteroresistant isolates were determined by polymerase chain reaction (PCR) and quantitative real-time PCR (qRT-PCR), respectively. Antisense RNA silencing was used to validate the function of eravacycline heteroresistant candidate genes. Twenty-five eravacycline heteroresistant isolates (17.36%) were detected among 144 CRAB isolates with eravacycline MIC values ≤4 mg/L while no eravacycline heteroresistant strains were detected in carbapenem-susceptible A. baumannii (CSAB) isolates. All eravacycline heteroresistant strains contained OXA-23 carbapenemase and the predominant multilocus sequence typing (MLST) was ST208 (72%). Cross-resistance was observed between eravacycline, tigecycline, and levofloxacin in the resistant subpopulations. The addition of efflux pump inhibitors significantly reduced the eravacycline MIC in resistant subpopulations and weakened the formation of eravacycline heteroresistance in CRAB isolates. The expression levels of adeABC and adeRS were significantly higher in resistant subpopulations than in eravacycline heteroresistant parental strains (P < 0.05). An ISAba1 insertion in the adeS gene was identified in 40% (10/25) of the resistant subpopulations. Decreasing the expression of adeABC or adeRS by antisense RNA silencing significantly inhibited eravacycline heteroresistance. In conclusion, this study identified the emergence of eravacycline heteroresistance in CRAB isolates in China, which is associated with high expression of AdeABC and AdeRS.
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Acinetobacter baumannii , Tetraciclinas , Tipagem de Sequências Multilocus , Antibacterianos/farmacologia , beta-Lactamases/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , RNA Antissenso , China/epidemiologia , Testes de Sensibilidade MicrobianaRESUMO
In this study, composite hydrogels were prepared using a simple synthetic technique to adsorb methylene blue (MB) from water. The hydrogel comprised potassium persulfate (KPS) as the initiator, N,N'-methylene bisacrylamide as the crosslinking agent, and sodium hydroxide (NaOH) as the activator. It was employed to adsorb MB at different concentrations from water. The morphology and properties of PUL/PAM/GO composites were characterized through thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning electron microscopy. Moreover, the adsorption properties, adsorption isotherms, adsorption kinetics, adsorption thermodynamics, and swelling properties of the hydrogel for MB were investigated. The optimal ratio of PUL to AC was obtained as 6:1 by fixing the amount of PUL and loading AC of different masses. The maximum adsorption capacity was obtained as 591.4 mg/g. It also exhibited certain mechanical strength. The adsorption of MB conforms to pseudo-first-order kinetics and Langmuir isotherms. In this study, an environment-friendly, cheap, simple, and efficient way was presented for the composite hydrogel in the direction of water treatment.
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MIL-88A crystals with three different metal ligands (Fe, Al, FeAl) were prepared by hydrothermal method for the first time. The three materials' crystal structure and surface morphology are different, leading to different adsorption properties of Congo red (CR). The maximum adsorption capacities of MIL-88A (Fe), MIL-88A (FeAl), and MIL-88A (Al) are 607.7 mg · g-1, 536.4 mg · g-1, and 512.1 mg · g-1 respectively. In addition, MIL-88A was combined with chitosan (CS) respectively, and MIL-88A/CS composite sponge was prepared by the freeze-drying method, which not only solved the defect that MIL-88A powder was difficult to recover but also further improved the removal ability of CR by the adsorbent. The maximum adsorption capacities of MIL-88A (FeAl)/CS, MIL-88A (Fe)/CS, MIL-88A (Al)/CS, and CS are 1312 mg · g-1, 1056 mg · g-1, 996.7 mg · g-1, and 769.6 mg · g-1, respectively. The structure and physicochemical properties of the materials were analyzed by SEM, FTIR, XRD, TGA, BET, and Zeta. The adsorption process of CR follows pseudo-second-order kinetics and Langmuir, Sips isotherm model. Combined with thermodynamic parameters, the adsorption behavior was described as endothermic monomolecular chemical adsorption. The removal of CR is attributed to electrostatic interactions, hydrogen bonding, metal coordination effects, and size-matching effects.
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Quitosana , Poluentes Químicos da Água , Vermelho Congo , Quitosana/química , Adsorção , Termodinâmica , Poluentes Químicos da Água/química , CinéticaRESUMO
Zirconium alginate/graphene oxide (ZA/GO) hydrogel spheres were prepared by crosslinking sodium alginate and GO with Zr4+. Then Zr4+ on the surface of the ZA/GO substrate acted as the metal nucleation site of the UiO-67 crystal and interacted with the organic ligand biphenyl 4-4'-dicarboxylic acid (BPDC) to make UiO-67 grow in situ on the surface of the ZA/GO hydrogel sphere by the hydrothermal method. The BET surface areas of ZA/GO, ZA/UiO-67, and ZA/GO/UiO-67 aerogel spheres were 1.29, 47.71, and 89.33 m2/g respectively. The maximum adsorption capacities of ZA/GO, ZA/UiO-67, and ZA/GO/UiO-67 aerogel spheres for methylene blue (MB) at room temperature (298 K) were 145.08, 307.49, and 1105.23 mg/g respectively. The kinetic analysis showed that the adsorption process of MB on the ZA/GO/UiO-67 aerogel sphere was consistent with the pseudo-first-order kinetic model. Isotherm analysis showed that MB was adsorbed on ZA/GO/UiO-67 aerogel spheres as a single layer. Thermodynamic analysis showed that the adsorption process of MB on the ZA/GO/UiO-67 aerogel sphere was exothermic and spontaneous. Adsorption of MB on ZA/GO/UiO-67 aerogel spheres is mainly dependent on π-π bond, electrostatic interaction, and hydrogen bond. After 8 cycles, ZA/GO/UiO-67 aerogel spheres still showed high adsorption performance and good reuse ability.
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Grafite , Poluentes Químicos da Água , Azul de Metileno/química , Cinética , Adsorção , Alginatos/química , Poluentes Químicos da Água/química , Grafite/química , HidrogéisRESUMO
This paper presents the first investigation of the adsorption performance of methylene blue by the nitro-functionalized metal-organic framework (MIL-88B-NO2). MIL-88B-NO2 has a specific surface area of 836.0 m2/g, which is 109.8 % higher than MIL-88B. The maximum adsorption capacity of methylene blue is 383.6 mg/g, which is 68.2 % higher than that of MIL-88B. This phenomenon can be attributed to the great increase in specific surface area and the introduction of nitro-functional groups. However, its microcrystalline nature makes it difficult to remove in practical applications and quickly causes secondary pollution. Therefore, the composite of MIL-88B-NO2 and calcium alginate (CA) to form aerogel maintains the inherent properties of the two materials and makes it easy to recycle. The utmost adsorption capability of MIL-88B-NO2/CA-2 aerogel is 721.0 mg/g. Compared with MIL-88B-NO2, the adsorption performance of MIL-88B-NO2/CA-2 aerogel is further improved by 88.0 %. The higher adsorption capacity of the adsorbent may be due to the synergistic interplay of electrostatic attraction, π-π conjugation, hydrogen bonding, metal coordination effect, and physicochemical properties. Also, MIL-88B-NO2/CA-2 aerogel has good recyclability, indicating that it has broad application prospects in the removal of positive dyes in contaminated water.
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Azul de Metileno , Água , Adsorção , Água/química , Dióxido de Nitrogênio , Metais , Compostos Radiofarmacêuticos , EsqueletoRESUMO
A chitosan/alginate/graphene oxide/UiO-67 (CS/SA/GO/UiO-67) amphoteric aerogel was synthesized successfully. A series of characterization experiments of CS/SA/GO/UiO-67 amphoteric aerogel was performed by SEM, EDS, FT-IR, TGA, XRD, BET, and zeta potential. The competitive adsorption properties of different adsorbents for complex dyes wastewater (MB and CR) at room temperature (298 K) were compared. Langmuir isotherm model predicted that the maximum adsorption quantity of CS/SA/GO/UiO-67 for CR and MB was 1091.61 and 1313.95 mg/g, respectively. The optimum pH values of CS/SA/GO/UiO-67 for the adsorption of CR and MB were 5 and 10, respectively. The kinetic analysis showed that the adsorption of MB and CR on CS/SA/GO/UiO-67 was more suitable for the pseudo-second-order and pseudo-first-order kinetic model, respectively. The isotherm study revealed that the adsorption of MB and CR was consistent with the Langmuir isotherm model. The thermodynamic study demonstrated that the adsorption process of MB and CR was exothermic and spontaneous. FT-IR analysis and zeta potential characterization experiments revealed that the adsorption mechanism of MB and CR on CS/SA/GO/UiO-67 depended on π-π bond, hydrogen bond, and electrostatic attraction. Repeatable experiments showed that the removal rates of MB and CR of CS/SA/GO/UiO-67 after six cycles of adsorption were 67.19 and 60.82 %, respectively.
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Quitosana , Corantes , Corantes/química , Quitosana/química , Espectroscopia de Infravermelho com Transformada de Fourier , Adsorção , Alginatos , CinéticaRESUMO
Micro-nano metal-organic framework (MIL-68(Fe)) for efficient adsorption of azo anionic dye Congo red (CR) was successfully prepared by one-step hydrothermal method under acidic environment. And a MIL-68(Fe)/chitosan composite sponge (MIL-68(Fe)/CS) was prepared under the coating of chitosan (CS). After comparing the performance of MIL-68(Fe) and MIL-68(Fe)/CS, we focus on exploring MIL-68(Fe)/CS. It ensured the CR removal efficiency while reaching the adsorption equilibrium faster than MIL-68(Fe), and solved the defect that the powder was difficult to be stripped by water after adsorption. The physicochemical properties and surface morphology of the adsorbent were characterized by SEM, FTIR, XRD, TGA, BET, and Zeta potential. The effects of pH, contact time, adsorbent dosage, initial solution concentration and temperature on the adsorption performance of the adsorbent were systematically analyzed. The pseudo-second-order model and the Sips model were most consistent for the adsorption process, indicating that the adsorption process of MIL-68(Fe)/chitosan composite sponge on CR is a complex physicochemical process. The removal rates of CR by MIL-68(Fe) and MIL-68(Fe)/chitosan composite sponge reached the maximum values of 99.55 % and 99.51 % at 318 K, respectively. And the maximum adsorption capacity of CR by MIL-68(Fe)/chitosan composite sponge at 318 K was 1184.16 mg·g-1. After six cycles of adsorption and desorption, the removal rate of CR was still higher than 80 %. The synergistic effects of π-π stacking, electrostatic interactions, hydrogen bonding and pore filling have important effects on CR removal.
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Quitosana , Estruturas Metalorgânicas , Poluentes Químicos da Água , Vermelho Congo , Quitosana/química , Adsorção , Compostos Azo , Poluentes Químicos da Água/química , Cinética , Concentração de Íons de HidrogênioRESUMO
The seismic damage state of building structure can be rapidly evaluated by coupling effect of structural displacement response and periodic characteristics. Firstly, the fundamental period calculation formula that adapts to the deformation pattern and distribution mode of horizontal seismic action for reinforced concrete frame structure is derived. Secondly, the seismic damage assessment standard of building structure considering period variation is established. Then, the seismic damage assessment method of building structure is constructed. Finally, the seismic damage example is used to verify the established evaluation method. The results show that the established research method has high accuracy and good engineering practicability.
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The research object is the ground-rested circular RC tank. The innovation is to reveal the hydrodynamic pressure law of ground-rested circular RC tanks under bi-directional horizontal seismic action. The relationship between the sloshing wave height and hydrodynamic pressure is determined, the hydrodynamic pressure components and their combination are verified, calculation methods for hydrodynamic pressure are developed, and their distribution laws are presented. The results show that convective hydrodynamic pressure cannot be ignored when the tank is subjected to seismic action. Hydrodynamic pressure under unidirectional horizontal seismic action in X or Y direction is obtained by square root of the sum of impulsive pressure squared and convective pressure squared. Total hydrodynamic pressure under bi-directional horizontal seismic action is obtained by the square root of the sum of X-direction hydrodynamic pressure squared and Y-direction hydrodynamic pressure squared. This method can ensure the accuracy and reliability of hydrodynamic pressure calculation.
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Hidrodinâmica , Reprodutibilidade dos TestesRESUMO
The regular structure provided by two-dimensional (2D) structural colloidal crystals is widely accepted to provide an ideal template that ensures that plasmonic bimetallic composite nanostructures are uniform. Herein, we report an effective method for fabricating bimetallic Au-Ag composite films loaded on the surfaces of 2D polystyrene@polyacrylic acid (PS@PAA) colloidal crystals. PS@PAA particles coated with uniform Ag particle layers (AgFON) were produced by a simple and effective sputtering-deposition technique, after which the galvanic replacement (GR) reaction was used to produce a bimetallic (Au-Ag)FON composite film at the liquid/solid interface in aqueous HAuCl4. The morphology and relative contents of the bimetallic (Au-Ag)FON composite film can be regulated by changing the kinetic factors that control the GR reaction, including the concentration and pH of the HAuCl4 solution, and the reaction time. We demonstrated that the fabricated bimetallic (Au-Ag)FON composite has localized surface plasmon resonance (LSPR) properties that can be regulated by varying the composite structure and Ag/Au composition. On the one hand, the regular 2D colloidal crystal structure provides an ideal template for preparing Au-Ag composite films, which ensures that the optical signals of plasmonic Au-Ag composite films are reproducible. On the other hand, the synergy between Ag and Au in the bimetallic alloy composite film ensures stable and tunable LSPR performance. Furthermore, the prepared 2D ordered (Au-Ag)FON Au-Ag bimetallic material is expected to be used in sensing and catalysis applications.
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The phenomenon that calcium alginate does not exhibit high adsorption capacity as a carrier material has not been reasonably explained or solved. In this paper, a new viewpoint that the orbital energy level of metal ions and the binding degree of the α-l-guluronate and ß-d-mannuronate units affect the adsorption performance of the composite was innovatively proposed. Taking barium alginate (BA) as an example, the possibility of replacing calcium alginate is discussed. Barium alginate/graphene oxide (BA/GO) membranes and three-dimensional (3D) barium alginate-bentonite-graphene oxide derived (3D-BA) hydrogels were prepared by vacuum freeze-drying to remove methylene blue. The structure and morphology of the prepared adsorbents were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and Fourier transform infrared spectroscopy. The effects of adsorbent dosage, doping ratio, temperature, contact time, pH value and initial dye concentration on the adsorption performance of BA composites were investigated. The adsorption capacities of the BA/GO and 3D-BA materials were 1011.3 and 710.3 mg/g, respectively. The BA/GO membrane exhibited stable filtration performance against high concentrations of dyes. Benefiting from the strong interaction between bentonite, sodium alginate and Ba2+, the 3D-BA hydrogel showed higher thermal stability and better adsorption efficiency than other materials. The Elovich kinetic model and Sips equation can appropriately describe the adsorption process. The results show that barium alginate is a better carrier material than calcium alginate.