RESUMO
Photocatalytic ozonation is considered to be a promising approach for the treatment of refractory organic pollutants, but the design of efficient catalyst remains a challenge. Surface modification provides a potential strategy to improve the activity of photocatalytic ozonation. In this work, density functional theory (DFT) calculations were first performed to check the interaction between O3 and TiO2-OH (surface hydroxylated TiO2) or TiO2-F (surface fluorinated TiO2), and the results suggest that TiO2-OH displays better O3 adsorption and activation than does TiO2-F, which is confirmed by experimental results. The surface hydroxyl groups greatly promote the O3 activation, which is beneficial for the generation of reactive oxygen species (ROS). Importantly, TiO2-OH displays better performance towards pollutants (such as berberine hydrochloride) removal than does TiO2-F and most reported ozonation photocatalysts. The total organic carbon (TOC) removal efficiency reaches 84.4 % within two hours. This work highlights the effect of surface hydroxylation on photocatalytic ozonation and provides ideas for the design of efficient photocatalytic ozonation catalysts.
RESUMO
Recently, amorphous materials have gained great attention as an emerging kind of functional material, and their characteristics such as isotropy, absence of grain boundaries, and abundant defects are very likely to outrun the disadvantages of crystalline counterparts, such as low conductivity, and ultimately lead to improved charge transfer efficiency. Herein, we investigated the effect of amorphization on the charge transfer process and photocatalytic performance with a phosphonate-based metal-organic framework (FePPA) as the research object. Comprehensive experimental results suggest that compared to crystalline FePPA, amorphous FePPA has more distorted metal nodes, which affects the electron distribution and consequently improves the photogenerated charge separation efficiency. Meanwhile, the distorted metal nodes in amorphous FePPA also greatly promote the adsorption and activation of O2. Hence, amorphous FePPA exhibits a better performance of photocatalytic C(sp3)-H bond activation for selective oxidation of toluene to benzaldehyde. This work illustrates the advantages of amorphous MOFs in the charge transfer process, which is conducive to the further development of high performance MOFs-based photocatalysts.
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To observe the effect of puerarin on learning and memory function and tau phosphorylation in APP/PS1 transgenic mice, drugs were administered to 3-month old APP/PS1 transgenic mice. Learning and memory function of mice were assessed by Morris water maze test 3 months after treatment. Animals were decapitated after behavioral test. The levels of Aß were detected by ELISA, the expression of protein [tau, phosphorylated tau, GSK3ß and p-GSK3ß(Ser9)] were assessed by Western blot. Morris water maze test showed that the escape latency of APP/PS1 double transgenic mice was significantly longer than that of the normal control group, and the residence time of the original quadrant was significantly shorter. The escape latency of puerarin group was significantly shorter and the residence time of the original quadrant was prolonged compared with the model group. Compared with the normal control group, the levels of Aß in the cortex of APP/PS1 transgenic mice were increased, the expression of phosphorylated tau was significantly increased, and the expression of phosphorylated GSK3ß(Ser9) protein was decreased. Treatment with puerarin, the latency of APP/PS1 transgenic mice was significantly reduced, the level of Aß was decreased, the expression of phosphorylated tau was significantly decreased, and the expression of phosphorylated GSK3ß(Ser9) protein was increased. Puerarin improves the learning and memory impairment by reducing the formation of Aß, activating the GSK3ß signaling pathway, inhibiting the phosphorylation of tau in APP/PS1 double transgenic mice.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Disfunção Cognitiva/tratamento farmacológico , Isoflavonas/farmacologia , Proteínas tau/química , Peptídeos beta-Amiloides , Precursor de Proteína beta-Amiloide , Animais , Modelos Animais de Doenças , Aprendizagem em Labirinto , Camundongos , Camundongos Transgênicos , FosforilaçãoRESUMO
BACKGROUND: The global prevalence of autism spectrum disorder (ASD) is on the rise, and high levels of exposure to toxic heavy metals may be associated with this increase. Urine analysis is a noninvasive method for investigating the accumulation and excretion of heavy metals. The aim of this study was to identify ASD-associated urinary metal markers. METHODS: Overall, 70 children with ASD and 71 children with typical development (TD) were enrolled in this retrospective case-control study. In this metallomics investigation, inductively coupled plasma mass spectrometry was performed to obtain the urine profile of 27 metals. RESULTS: Children with ASD could be distinguished from children with TD based on the urine metal profile, with ASD children showing an increased urine metal Shannon diversity. A metallome-wide association analysis was used to identify seven ASD-related metals in urine, with cobalt, aluminum, selenium, and lithium significantly higher, and manganese, mercury, and titanium significantly lower in the urine of children with ASD than in children with TD. The least absolute shrinkage and selection operator (LASSO) machine learning method was used to rank the seven urine metals in terms of their effect on ASD. On the basis of these seven urine metals, we constructed a LASSO regression model for ASD classification and found an area under the receiver operating characteristic curve of 0.913. We also constructed a clinical prediction model for ASD based on the seven metals that were different in the urine of children with ASD and found that the model would be useful for the clinical prediction of ASD risk. CONCLUSIONS: The study findings suggest that altered urine metal concentrations may be an important risk factor for ASD, and we recommend further exploration of the mechanisms and clinical treatment measures for such alterations.
Assuntos
Transtorno do Espectro Autista , Metais Pesados , Criança , Humanos , Transtorno do Espectro Autista/epidemiologia , Transtorno do Espectro Autista/etiologia , Estudos de Casos e Controles , Estudos Retrospectivos , Modelos Estatísticos , Prognóstico , Espectrometria de MassasRESUMO
BACKGROUND: Echinacoside (ECH) is a phenylethanoid extracted from the stems of Cistanches salsa, an herb used in Chinese medicine formulations, and is effective against glioblastoma multiforme (GBM). Epithelial-mesenchymal transition (EMT) is the cornerstone of tumorigenesis and metastasis, and increases the malignant behavior of GBM cells. The S phase kinase-related protein 2 (skp2), an oncoprotein associated with EMT, is highly expressed in GBM and significantly associated with drug resistance, tumor grade and dismal prognosis. The aim of this study was to explore the inhibitory effects of ECH against GBM development and skp2-induced EMT. METHODS: CCK-8, EdU incorporation, transwell, colony formation and sphere formation assays were used to determine the effects of ECH on GBM cell viability, proliferation, migration and invasion in vitro. The in vivo anti-glioma effects of ECH were examined using a U87 xenograft model. The expression levels of skp2 protein, EMT-associated markers (vimentin and snail) and stemness markers (Nestin and sox2) were analyzed by immunofluorescence staining and western blotting experiments. RESULTS: ECH suppressed the proliferation, invasiveness and migration of GBM cells in vitro, as well as the growth of U87 xenograft in vivo. In addition, ECH downregulated the skp2 protein, EMT-related markers (vimentin and snail) and stemness markers (sox2 and Nestin). The inhibitory effects of ECH were augmented in the skp2-knockdown GBM cells, and reversed in cells with ectopic expression of skp2. CONCLUSION: ECH inhibits glioma development by suppressing skp2-induced EMT of GBM cells.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Glicosídeos , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioma/metabolismo , Glioma/patologia , Glicosídeos/farmacologia , Humanos , Nestina/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Sincalida/metabolismo , Vimentina/metabolismoRESUMO
Neuroblastoma is one of the leading causes of cancerassociated mortality worldwide, particularly in children, partially due to the absence of effective therapeutic targets and diagnostic biomarkers. Therefore, novel molecular targets are critical to the development of therapeutic approaches for neuroblastoma. In the present study, the functions of zinc transporter ZIP8 (Zip8), a member of the zinc transporting protein family, were investigated as novel molecular targets in neuroblastoma cancer cells. The proliferation rates of neuroblastoma cancer cells were significantly decreased when Zip8 was knocked down by lentiviralmediated RNA interference. Study of the molecular mechanism suggested that Zip8 modulated the expression of key genes involved in the nuclear factorκB signaling pathway. Furthermore, Zip8 depletion suppressed the migratory potential of neuroblastoma cancer cells by reducing the expression levels of matrix metalloproteinases. In conclusion, the results of the present study suggested that Zip8 was an important regulator of neuroblastoma cell proliferation and migration, indicating that Zip8 may be a potential anticancer therapeutic target and a promising diagnostic biomarker for human neuroblastoma.