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Overuse of chlorinated disinfectants leads to a significant accumulation of disinfection by-products. Trichloroacetic acid (TCA) is a typical carcinogenic disinfection by-product. The efficacy of the conventional degradation process is reduced by the complex nature of its structure, causing a yearly increase in its prevalence within the ecological environment and consequent infliction of significant harm. In this paper, TCA was chosen as the research subject, Fe/Ni bimetallic nanoparticles were employed as the reducing catalyst, ZIF-8@HMON as the catalytic carrier combined with Fe/Ni nanoparticles, and peroxymonosulfate (PMS) was introduced to construct the reducing-advanced oxidation synergistic system and investigated the effect of this system on the degradation performance and degradation pathway of TCA. Various characterization techniques, including TEM, SEM, XRD, FT-IR, XPS, BET, were employed to investigate the morphology, element composition and structure of composite materials analysis. Moreover, the conditions for TCA degradation can be optimized by changing the experimental environment. The results showed that 25 mg of composite catalyst (mole ratio Fe: Ni = 1:1) and 10 mg of PMS effectively degraded TCA within 20-80 mg/L range at pH = 3 and 55 °C, achieving maximum degradation within 20 min. Finally, the potential pathways of TCA degradation were analyzed using EPR and LC-MS, and the corresponding reaction mechanisms were proposed.
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Nanopartículas , Ácido Tricloroacético , Espectroscopia de Infravermelho com Transformada de Fourier , Peróxidos/química , Nanopartículas/químicaRESUMO
The inefficiency of catalysts in sulfate radical-based advanced oxidation processes (SR-AOPs) is primarily attributed to the sluggish circulation of redox couples. Herein, a carbon defects-enriched NBC-C3N5@CoMn (NCC) was synthesized through a self-assembly approach. The carbon defects within the NCC induce the electron trap effect, thereby facilitating the efficient cycling of redox couples in photo-Fenton-like processes during contaminant degradation. This effect enables the self-regeneration of the NCC catalyst. The reductive redox couples (Co (II) and Mn (II)) are continuously regenerated following the degradation process. Within the NCC, CoMn layered double hydroxides (LDHs) act as primary active sites, promoting the generation of hydroxyl radicals (â¢OH), sulfate radicals (SO4â¢-) and singlet oxygen (1O2) through continuous electron gain and loss. Additionally, the internal electric field established within the NCC further accelerates electron transfer. Density Functional Theory (DFT) calculations confirm that the carbon defects-enriched NCC exhibits lower adsorption energies and higher electron transfer efficiencies than carbon defect-deficient NCC. This study introduces a novel photocatalyst with self-regenerating capabilities, presenting an innovative approach to regulate redox couples in SR-AOPs for sustainable degradation.
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Carbono , Oxirredução , Carbono/química , Catálise , Radical Hidroxila/químicaRESUMO
BACKGROUND: Major psychiatric disorders such as schizophrenia (SCZ) and bipolar disorder (BPD) are complex genetic mental illnesses. Their non-Mendelian features, such as those observed in monozygotic twins discordant for SCZ or BPD, are likely complicated by environmental modifiers of genetic effects. 5-Hydroxymethylcytosine (5hmC) is an important epigenetic mark in gene regulation, and whether it is linked to genetic variants that contribute to non-Mendelian features remains largely unexplored. METHODS: We combined the 5hmC-selective chemical labeling method (5hmC-seq) and whole-genome sequencing (WGS) analysis of peripheral blood DNA obtained from monozygotic (MZ) twins discordant for SCZ or BPD to identify allelic imbalances in hydroxymethylome maps, and examined association of allele-specific hydroxymethylation (AShM) transition with disease susceptibility based on Bayes factors (BF) derived from the Bayesian generalized additive linear mixed model. We then performed multi-omics integrative analysis to determine the molecular pathogenic basis of those AShM sites. We finally employed luciferase reporter, CRISPR/Cas9 technology, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), PCR, FM4-64 imaging analysis, and RNA sequencing to validate the function of interested AShM sites in the human neuroblastoma SK-N-SH cells and human embryonic kidney 293T (HEK293T) cells. RESULTS: We identified thousands of genetic variants associated with AShM imbalances that exhibited phenotypic variation-associated AShM changes at regulatory loci. These AShM marks showed plausible associations with SCZ or BPD based on their effects on interactions among transcription factors (TFs), DNA methylation levels, or other epigenomic marks and thus contributed to dysregulated gene expression, which ultimately increased disease susceptibility. We then validated that competitive binding of POU3F2 on the alternative allele at the AShM site rs4558409 (G/T) in PLLP-enhanced PLLP expression, while the hydroxymethylated alternative allele, which alleviated the POU3F2 binding activity at the rs4558409 site, might be associated with the downregulated PLLP expression observed in BPD or SCZ. Moreover, disruption of rs4558409 promoted neural development and vesicle trafficking. CONCLUSION: Our study provides a powerful strategy for prioritizing regulatory risk variants and contributes to our understanding of the interplay between genetic and epigenetic factors in mediating SCZ or BPD susceptibility.
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Esquizofrenia , Gêmeos Monozigóticos , Humanos , Teorema de Bayes , Alelos , Gêmeos Monozigóticos/genética , Células HEK293 , Metilação de DNA/genética , Esquizofrenia/genética , Predisposição Genética para Doença , Epigênese Genética/genéticaRESUMO
Schizophrenia is a complex genetic disorder, the non-Mendelian features of which are likely complicated by epigenetic factors yet to be elucidated. Here, we performed RNA sequencing of peripheral blood RNA from monozygotic twins discordant for schizophrenia, and identified a schizophrenia-associated upregulated long noncoding RNA (lncRNA, AC006129.1) that participates in the inflammatory response by enhancing SOCS3 and CASP1 expression in schizophrenia patients and further validated this finding in AC006129.1-overexpressing mice showing schizophrenia-related abnormal behaviors. We find that AC006129.1 binds to the promoter region of the transcriptional repressor Capicua (CIC), facilitates the interactions of DNA methyltransferases with the CIC promoter, and promotes DNA methylation-mediated CIC downregulation, thereby ameliorating CIC-induced SOCS3 and CASP1 repression. Derepression of SOCS3 enhances the anti-inflammatory response by inhibiting JAK/STAT-signaling activation. Our findings reveal an epigenetic mechanism with etiological and therapeutic implications for schizophrenia.
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Metilação de DNA , RNA Longo não Codificante , Esquizofrenia , Proteína 3 Supressora da Sinalização de Citocinas , Animais , Regulação para Baixo , Humanos , Inflamação , Camundongos , RNA Longo não Codificante/genética , Esquizofrenia/genética , Proteína 3 Supressora da Sinalização de Citocinas/genética , Proteína 3 Supressora da Sinalização de Citocinas/metabolismoRESUMO
Ellipsoidal-Fe3O4@SiO2@mSiO2-C18@dopamine hydrochloride-graphene quantum dots-folic acid (ellipsoidal-HMNPs@PDA-GQDs-FA), a dual-functional drug carrier, was stepwise constructed. Theα-Fe2O3ellipsoidal nanoparticles were prepared by a hydrothermal method, and then coated with SiO2by Stöber method. The resulting core-shell structure, Fe3O4@SiO2@mSiO2-C18magnetic nano hollow spheres, abbreviated as HMNPs, was finally grafted with graphene quantum dots (GQDs), dopamine hydrochloride (PDA) and folic acid (FA) by amide reaction to obtain HMNPs@PDA-GQDs-FA. Transmission electron microscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy and element analysis proved the successful construction of the HMNPs@PDA-GQDs-FA nanoscale carrier-cargo composite. The carrier HMNPs@PDA-GQDs-FA has higher load (51.63 ± 1.53%) and release (38.56 ± 1.95%) capacity for gambogic acid (GA). Cytotoxicity test showed that the cell survival rate was above 95%, suggesting the cytotoxicity of the carrier-cargo was very low. The cell lethality (74.91 ± 1.2%) is greatly improved after loading GA because of the magnetic targeting of HMNPs, the targeting performance of FA to tumor cells, and the pH response to the surrounding environment of tumor cells of PDA. All results showed that HMNPs@PDA-GQDs-FA had good biocompatibility and could be used in the treatment of VX2 tumor cells after loading GA.
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Grafite , Pontos Quânticos , Pontos Quânticos/química , Grafite/farmacologia , Grafite/química , Ácido Fólico , Dióxido de Silício , DopaminaRESUMO
Atomic-scale catalysts leverage the advantages of both heterogeneous catalysts for their stability and reusability and homogeneous catalysts for their isolated active sites. Here, a palladium catalyst supported by Si-thiol, a commercially available mercaptopropyl-modified and TMS-passivated amorphous silica, was synthesized and characterized by SEM,TEM, aberration-corrected STEM-HAADF, XRD, FT-IR and XPS. Statistical analysis revealed that the catalytic Pd species predominantly consisted of intermediate sized nanoparticles (<2 nm), small amounts of essentially isolated atoms (ca. 0.1 nm), and limited amounts of somewhat larger nanoparticles (<5 nm). The nanoscale atomic clusters dominated the reactivity and served as the key active sites for Suzuki coupling. The outcomes of the reaction were greatly affected by the choice of solvents, and Pd/Si-thiol was demonstrated to be reusable for more than three times without a noticeable loss of catalytic activity. [Formula: see text].
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Magnetic fluids (MFs) with good dispersion were prepared by speed-controlled co-precipitation method, using polyethylene glycol (PEG-4000) as dispersing agent. To functionalize the MFs with graphene oxide (GO), highly dispersed nano-magnetic particles (NMPs) were firstly prepared by low-temperature freeze-drying technique. 3-aminopropyltriethoxysilane (APTES) was then attached on the surface of NMPs to form amino functionalized NMPs. GO was finally assembled with amino functionalized NMPs, to prepare GO functionalized MFs (GO-NMPs) by electrostatic adsorption. The obtained GO-NMPs were then characterized by FTIR, XRD, TEM, SEM and VSM. Meanwhile, mice were in vivo used as animal model to study biological application of 99Tcm labeled GO-NMPs, suggesting that the targeted functionalized magnetic particles had higher magnetic response effect under pulsed magnetic gradient field.
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The ultra-small superparamagnetic iron oxide (USPIO) particles with high saturation magnetization and good superparamagnetism were prepared by reverse micro-emulsions using novel C16E15 as surfactant, which can reduce magnetic dipole-dipole interaction, hence decreasing the critical blocking temperature (TB). Powder X-ray diffraction (XRD), Infrared spectrum (FT-IR), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Vibrating sample magnetometer (VSM) were used to characterize the magnetic particles. The higher ratio of Fe2+/Fe3+ caused redundant FeO on the USPIO surface. An in vitro approach model for simulating target delivery of USPIO particles to sites of interest was developed to illustrate the relationship between magnetic fluid retention rate and pole distance. In Vivo targeted interception and magnetic targeting bio-distribution of superparamagnetic particles were also investigated simultaneously. The results indicated that the USPIO had high ability for magnetic focusing in mimetic surrounding tissue surrounding blood vessels under the action of pulsed magnetic field. The USPIO nanoparticles will be fundamental in biomedical applications.
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Nanopartículas de Magnetita , Espectroscopia de Infravermelho com Transformada de Fourier , Magnetismo , Distribuição Tecidual , Difração de Raios XRESUMO
In the present work, three differently shaped mesoporous silica nanoparticles, spherical nano-SiO2, tubular mesoporous SiO2 and vesicle-like mesoporous SiO2 (VSL), were prepared and used to immobilize Horse radish peroxidase (HRP), and their enzyme's activity was also evaluated. It was found that the VSL immobilized HRP displayed higher specific activity than free enzyme and other two differently shaped silica immobilized HRP. After immobilization, the thermal stability, pH tolerance resistance and storage stability on vesicle-like SiO2 were studied as well. In addition, the kinetic constants Km and Vmax for HRP were significantly altered by immobilization. The affinity for HRP towards its substrate increased (with decreasing Km), leading to enhanced catalytic efficiency (with increased Vmax). Moreover, the reusability for degradation of methoxychlor (MXC) by VSL immobilized enzyme was studied and its degradation products were detected by GC-MS and NMR analysis.
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Estabilidade Enzimática , Peroxidase do Rábano Silvestre/metabolismo , Nanoestruturas , Dióxido de Silício/química , Enzimas Imobilizadas , Metoxicloro , TemperaturaRESUMO
We report the design of two collagen-mimetic peptide sequences, NSI and NSII, that self-assemble into structurally defined nanoscale sheets. The underlying structure of these nanosheets can be understood in terms of the layered packing of collagen triple helices in two dimensions. These nanosheet assemblies represent a novel morphology for collagen-based materials, which, on the basis of their defined structure, may be envisioned as potentially biocompatible platforms for controlled presentation of chemical functionality at the nanoscale. The molecularly programmed self-assembly of peptides NSI and NSII into nanosheets suggests that sequence-specific macromolecules offer significant promise as design elements for two-dimensional (2D) assemblies. This investigation provides a design rubric for fabrication of structurally defined, peptide-based nanosheets using the principles of solution-based self-assembly facilitated through complementary electrostatic interactions.
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Colágeno/química , Ouro/química , Nanopartículas Metálicas/química , Peptídeos/química , Sequência de Aminoácidos , Dados de Sequência Molecular , Tamanho da Partícula , Conformação Proteica , Propriedades de SuperfícieRESUMO
In this article, we review our recent work on mid-infrared (mid-IR) photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiN x waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors.
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The structure of (S)-5-(3-acetyl-5-chloro-2-ethoxy-6-fluorophenyl)-2-oxazolidinone, C13H13ClFNO4, at 100â K has monoclinic (P21) symmetry. The compound has a polymeric structure propagated by a screw axis parallel to the b axis with N-Hâ¯O hydrogen bonding. It is of inter-est with respect to efforts in the synthesis of a candidate anti-cancer drug, parsaclisib.
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Laccase immobilized and cross-linked on Fe3S4/earthworm-like mesoporous SiO2 (Fe3S4/EW-mSiO2) was used to degrade methoxychlor (MXC) in aqueous environments. The effects of various parameters on the degradation of MXC were determined using free and immobilized laccase. Immobilization improved the thermal stability and reuse of laccase significantly. Under the conditions of pH 4.5, temperature 40 °C, and reaction time 8 h, the degradation rate of MXC by immobilized laccase reached a maximum value of 40.99% and remained at 1/3 of the original after six cycles. The excellent degradation performance of Fe3S4/EW-mSiO2 was attributable to the pyrite (FeS2) impurity in Fe3S4, which could act as an electron donor in reductive dehalogenation. Sulfide groups and Fe2+ reduced the activation energy of the system resulting in pyrite-assisted degradation of MXC. The degradation mechanism of MXC in aqueous environments by laccase immobilized on Fe3S4/EW-mSiO2 was determined via mass spectroscopy of the degradation products. This study is a new attempt to use pyrite to support immobilized laccase degradation.
Assuntos
Ferro , Metoxicloro , Oligoquetos , Animais , Metoxicloro/química , Enzimas Imobilizadas/química , Lacase/metabolismo , Dióxido de Silício/química , Oligoquetos/metabolismo , SulfetosRESUMO
We have demonstrated what we believe to be the first waveguide photonic crystal cavity operating in the mid-infrared. The devices were fabricated from Ge23Sb7S70 chalcogenide glass (ChG) on CaF2 substrates by combing photolithographic patterning and focused ion beam milling. The waveguide-coupled cavities were characterized using a fiber end fire coupling method at 5.2 µm wavelength, and a loaded quality factor of ~2000 was measured near the critical coupling regime.
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Flexible piezoelectric PZT/fabric composite material is pliable and tough in nature which is in a lack of traditional PZT patches. It has great application prospect in improving the sensitivity of sensor/actuator made by piezoelectric materials especially when they are used for curved surfaces or complicated conditions. In this paper, glass fiber cloth was adopted as carrier to grow PZT piezoelectric crystal particles by hydrothermal method, and the optimum conditions were studied. The results showed that the soft glass fiber cloth was an ideal kind of carrier. A large number of cubic-shaped PZT nanocrystallines grew firmly in the carrier with a dense and uniform distribution. The best hydrothermal condition was found to be pH 13, reaction time 24 h, and reaction temperature 200°C.
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Titânio/química , Zircônio/química , Vidro/química , Concentração de Íons de Hidrogênio , TemperaturaRESUMO
The presence of methoxychlor (MXC) in soil and wastewater is considered a nonnegligible environmental threat. Herein, Fe3O4@Fe(0) was obtained by NaBH4 reduction of Fe3O4 nanoparticles and served as a carrier for laccase to construct catalyst. The catalyst was evaluated for the degradation of MXC in treated wastewater and soil with 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) being used as cocatalyst. The removal rate of MXC in wastewater and soil was found to be 89% and 88% in optimum conditions, and the influences of initial MXC concentration, pH, and temperature on the degradation rate were evaluated. The metabolites including 2-methylpentane, 3-methylpentane, and n-pentane of MXC were identified, and possible degradation mechanisms were proposed. Overall, this work successfully demonstrates not only the ability to degrade MXC in different circumstances but also provides a new idea for environmental remediation in the future.
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Enzimas Imobilizadas , Metoxicloro , Águas Residuárias , Catálise , SoloRESUMO
The "trinitrogen" [ammonia nitrogen (NH4+ - N), nitrate nitrogen (NO3- - N), and nitrite nitrogen (NO2- - N)] from industrial or domestic wastewater can lead to eutrophication of water bodies. When ammonia nitrogen is converted into nitrate nitrogen, it will cause high nitrogen oxygen demand, which will also lead to hyperammonemia. High nitrite content in water bodies will increase the risk of human cancer. In this paper, Fe-Ce bimetallic-doped composites (Fe-Ce/SiO2 and Fe-Ce-SiO2/TiO2) were synthesized using SiO2 aerogel as a carrier for the adsorption and degradation of "three nitrogen."SiO2/TiO2 was prepared by dipping method, and Fe and Ce bimetals were loaded on the surface of SiO2/TiO2 material, and the effect of photo-Fenton oxidation on the degradation rate of three nitrogen under different materials was explored. The results showed that when the dosage of catalyst was 0.01 g, pH value was 11.0, and the concentration of H2O2 was 80 mmol/L, the photocatalytic efficiency was the best, and the degradation efficiency of three nitrogen remained above 70%.