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Magnetic separation of photocatalysts holds great promise for water treatment. A magnetic separation method has a positive effect on the recovery of catalysts after degradation. In this paper, an efficient and reusable catalytic system is developed based on coating magnetic Fe3O4 by depositing Fe2+ on the surface of ZnO. The Fe3O4/ZnO nanocomposite exhibits enhanced performance for organic pollutant degradation. The Fe3O4/ZnO system demonstrates a high photocatalytic activity of 100% degradation efficiency in Rhodamine B (RhB) degradation under UV light irradiation for 50 min. The excellent photocatalytic activity is primarily due to the separation of photogenerated electron-hole pairs being facilitated by the strong interaction between Fe3O4 and ZnO. The induction of the magnetic Fe3O4 endows the Fe3O4/ZnO composite with superior magnetic separation capability from water. Experiments with different radical scavengers revealed that the hydroxyl radical (·OH) is the key reactive radical for the effective degradation of RhB. This work innovatively affords a common interfacial dopant deposition strategy for catalytic application in the degradation of organic dye pollutants and catalyst separation from wastewater efficiently.
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Compared with a single semiconductor, the heterojunction formed by two different semiconductors usually has higher light utilization and better photoelectric performance. By using stable TiO2 nanotubes as the main subject, CdSe/TiO2NTs heterojunctions were synthesized by a hydrothermal method. XRD, TEM, SEM, PL, UV-vis, and EIS were used to characterize the fabricated CdSe/TiO2NTs. Under visible light irradiation, CdSe/TiO2NTs heterojunctions exhibited a higher absorption intensity and lower degree of photogenerated carrier recombination than TiO2. The electrons and holes were proven to be effectively separated in this heterojunction via theoretical calculation. Under CdSe/TiO2NTs' optimal conditions, the glucose concentrations (10-90 µM) had a linear relationship with the photocurrent value, and the detection limit was 3.1 µM. Moreover, the CdSe/TiO2NTs sensor exhibited good selectivity and stability. Based on the experimental data and theoretical calculations, its PEC sensing mechanism was also illuminated.
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Compostos de Cádmio , Compostos de Selênio , Compostos de Cádmio/química , Compostos de Selênio/química , Titânio/química , GlucoseRESUMO
A pink-coloured, Gram-stain-positive, aerobic and rod-shaped strain, designated 75T, was isolated from Collins glacier front till, Antarctica. Strain 75T was non-motile and non-spore-forming. Growth was observed at pH 6.0-9.0 (optimum, pH 7.0), at 4-45 °C (optimum, 20 °C) and with 0-9â% (w/v) NaCl (optimum, 1%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain 75T belongs to the genus Rhodococcus, and is related to Rhodococcus gannanensis DSM 104003T, Rhodococcus aerolatus KCTC29240T and Rhodococcus agglutinans KCTC 39118T (96.1, 96.0 and 95.7â% sequence similarity, respectively). The main polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and a phosphoglycolipid. The major cellular fatty acids were identified as C16â:â0, iso- C16â:â0, 10-methyl C17â:â0 and C17â:â1 ω8c. MK-7 and MK-8(H4) were found to be the dominant menaquinones. Whole-cell hydrolysates contained meso-diaminopimelic acid, ribose, galactose, glucose and rhamnose. The genome of strain 75T is 3.82 Mb long in size with a G+C content of 73.1 mol%. On the basis of phenotypic, molecular and chemotaxonomic characteristics, strain 75T is considered to represent a novel species of the genus Rhodococcus, for which the name Rhodococcus antarcticus sp. nov. is proposed. The type strain is 75T (=CCTCC AA 2019032T=KCTC 49334T).
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Ácidos Graxos , Rhodococcus , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , RNA Ribossômico 16S/genética , Regiões Antárticas , Camada de Gelo , Composição de Bases , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
The objective of the tandem hydroformylation-hydrogenation of alkenes to corresponding alcohols was to design an efficient and stable heterogeneous catalyst. To this end, a series of novel heterogeneous graphitic carbon nitride (g-CN) supported bimetallic Rh-Co nanoparticle catalysts (Rh-Co/g-CN) were prepared and subsequently studied for this one-pot two-step reaction. The lamellar structure makes Rh and Co nanoparticles with diameters of <1â nm and 20â nm, respectively, homogeneously deposited on the surface of g-CN layers, exhibit remarkable conversion of styrene (99.9 %) and chemoselectivity for alcohol (87.8 %). More importantly, Co nanoparticles are found to play an important role in the improvement of the chemoselectivity for alcohol due to the formation of catalytic active species [HCo(CO)y ]. Besides the detailed investigation of the catalytic properties of Rh-Co/g-CN under different reaction conditions, the reuse of Rh-Co/g-CN was conducted for five times and no evident decrease in the activity and chemoselectivity was observed. Therefore, we expect that this work could offer an initial insight into g-CN-based heterogeneous catalyst on the tandem hydroformylation-hydrogenation reaction.
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Alcenos , Nanopartículas , Hidrogenação , EtanolRESUMO
Studies have shown that political participation does not only affect the flow of public resources but also creates positive feedback on participants' subjective perceptions. However, research on the relationship between political participation and the life satisfaction of Chinese urban residents is relatively scarce. Thus, this study investigates whether political participation helps improve the life satisfaction of Chinese urban residents. Based on 2577 samples of the 2015 Chinese Social Survey this study used the Ordinary least squares model, instrumental variable model, and propensity score matching model to explore the relationship between political participation and the life satisfaction of Chinese urban residents. The empirical results show that political participation can significantly improve the life satisfaction of urban residents. Compared with urban residents without political participation, the life satisfaction of the political participants was 0.145 units higher at a 0.05 level of significance. In addition, this improved effect varied in degree among different groups of urban residents and was more significant for females, members of the Communist Party of China, highly educated, and employed urban residents. In China, there is a significant relationship between political participation and the life satisfaction of urban residents, with the life satisfaction of urban residents improving significantly through political participation. There are differences in the level of this improved effect among different urban residents, and it is more significant for females, highly educated, members of the Communist Party, and employed urban residents. To improve the life satisfaction of Chinese urban residents, it is necessary to further broaden their political participation channels.
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Satisfação Pessoal , População Rural , Povo Asiático , China , Feminino , Humanos , População UrbanaRESUMO
Osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) biofilm infection is difficult to eradicate and can even be life-threatening. Given that the infection is persistent and deep-seated in the bone tissue, controlled and efficient treatment of osteomyelitis remains challenging. Herein, an activatable nanostructure (Au/TNT@PG) is presented for synergistic sonodynamic-catalytic therapy of MRSA-infected osteomyelitis. The Au/TNT@PG backbone is obtained by conjugating a guanidinium-rich polymer (PG), a component that penetrates the biofilm matrix, onto ultrasound (US)-absorbing gold-doped titanate nanotubes (Au/TNTs). Under deep-penetrating US irradiation, the nanocomposite generates 1 O2 for sonodynamic therapy and catalyzes the decomposition of endogenous H2 O2 into toxic â¢OH in the acidic infection microenvironment for catalytic therapy, leading to bacterial cell death. Its robust antibacterial effectiveness is attributable to its bacteria-capturing ability, the biofilm penetrability of positively charged guanidinium, and the subsequent synergistic effect of sonodynamic-catalytic action of Au/TNT. Such a remotely controlled approach potentiates the polarization of macrophages to M2-type while suppressing the M1-type, leading to topical inflammation resolution and enhanced osteoblast proliferation and differentiation to inhibit bone loss. Therefore, this study provides a generic nanotherapeutic approach for efficient sonodynamic-catalytic therapy with respect to osteomyelitis.
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Staphylococcus aureus Resistente à Meticilina , Nanoestruturas , Osteomielite , Infecções Estafilocócicas , Humanos , Guanidina/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Osteomielite/diagnóstico por imagem , Osteomielite/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/química , Nanoestruturas/uso terapêuticoRESUMO
In today's age of resource scarcity, the low-cost development and utilization of renewable energy, e.g., hydrogen energy, have attracted much attention in the world. In this work, cheap natural halloysite nanotubes (HNTs) were modified with γ-aminopropyltriethoxysilane (APTES), and the functionalized HNTs were used as to support metal (Pd, Au, Ag) catalysts for dehydrogenation of formic acid (DFA). The supports and fabricated catalysts were characterized with ICP, FT-IR, XRD, XPS and TEM. The functional groups facilitate the anchoring of metal particles to the supports, which brings about the high dispersion of metallic particles in catalysts. The catalysts show high activity against DFA and exhibit selectivity of 100% toward H2 at room temperature or less. The interactions between active centers and supports were investigated by evaluation and comparison of the catalytic performances of Pd/NH2-HNTs, PdAg/NH2-HNTs and PdAu/NH2-HNTs for DFA.
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The aim of this study was assessing the mechanism of nanometric bone pulp activated with double gene as bone morphogenetic protein 1 (BMP-1) and vascular endothelial growth factor (VEGF) in improving the strength of centrum in osteoporosis (OP). The model of nanometric bone pulp activated with BMP-1 and VEGF double gene was established and validated. Under maximum condition of load and collapsed fragments, the model was analyzed through biomechanical test. The conditions for ALP, BGP, MLL and BMD in the model were also analyzed, and three-dimensional structural transformation was analyzed. Western blot and qRT-PCR were used to detect the effect of adding or not adding dual gene activated nano-bone stickers on OC-specific protein and mRNA; ELISA kits were used to detect the changes of RANKL pathway RANKL, OPG and TRACP5b. The maximum conformed quality and condensed intensity were strengthened with the nanometric bone pulp activated with BMP-1 and VEGF double gene. The maximum load in centrum was extremely elevated in the model, and the condition of ALP and its effect on bone was partly improved in the model. The precision and efficiency in the quality of BMD were continuously decreased. The BMD and MLF were strengthened notably in the model, and their effect on the bone was extremely improved. There was tight displayed model of trabecular in centrum and porosity was also continuously reduced. After adding the double-gene activated nano-bone stickers, the results from qRTPCR and Western blot showed that the changes of osteoclast-related genes and protein expressions were significantly down-regulated. The nanometric bone pulp activated with BMP-1 and VEGF double gene was one of ideal filled criterion. The BMD and bone strength were also elevated.
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Osteoporose , Fator A de Crescimento do Endotélio Vascular , Proteína Morfogenética Óssea 1 , Proteína Morfogenética Óssea 2 , Osso e Ossos/metabolismo , Humanos , Osteoporose/genética , Osteoporose/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Based on the enhanced charge separation efficiency of the one-dimensional structure and strong surface plasmon resonance (SPR) of gold, a gold modified TiO2 nanotube (Au/TiO2NTs) glucose photoelectrochemical (PEC) sensor was prepared. It could be activated by visible red light (625 nm). Under optimal conditions, the Au/TiO2NTs sensor exhibited a good sensitivity of 170.37 µA·mM-1·cm-2 in the range of 1-90 µM (R2 = 0.9993), and a detection limit of 1.3 µM (S/N = 3). Due to its high selectivity, good anti-interference ability, and long-term stability, the fabricated Au/TiO2NTs sensor provides practical detection of glucose. It is expected to be used in the construction of non-invasive PEC biosensors.
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The formation of heterojunction structures can effectively prevent the recombination of photogenerated electron-hole pairs in semiconductors and result in the enhancement of photoelectric properties. Using TiO2 nanotubes (prepared using the hydrothermal-impregnation method) as carriers, CdS-TiO2NTs were fabricated as a photoelectrochemical (PEC) sensor, which can be used under visible light and can exhibit good PEC performance due to the existence of the heterojunction structure. The experimental results show that the prepared CdS-TiO2NTs electrode had a linear response to 2-16 mM glutathione (GSH). The sensor's sensitivity and detection limit (LOD) were 102.9 µA·mM-1 cm-2 and 27.7 µM, respectively. Moreover, the biosensor had good stability, indicating the potential application of this kind of heterojunction PEC biosensor.
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Photocatalytic water splitting for hydrogen generation is a significant pathway for sustainable energy conversion and production. The photocatalysts with a Z-scheme water splitting charge transfer pathway is superior due to the good separation and migration ability of photoexcited charge carriers. Herein, Co3O4/g-C3N4 photocatalysts with Z-scheme charge transfer pathway were successfully constructed by an electrostatic interaction-annealing method. The as-prepared Co3O4/g-C3N4 ultra-thin nanosheets were tested and analyzed by XRD, EA, ICP, SEM, TEM, AFM, XPS, UV-Vis DRS, PL and photoelectrochemical measurements. Moreover, the influences of fabrication parameters on performance of Co3O4/g-C3N4 catalysts were investigated, and 0.5% Co3O4/g-C3N4 exhibited the optimal activity. Based on the characterization and catalytic performance, the Z-scheme charge transfer pathway of Co3O4/g-C3N4 was established and put forward. To further improve the catalytic performance of Co3O4/g-C3N4, 0.5% Pt was added as a co-catalyst. The obtained Pt/0.5% Co3O4/g-C3N4 was recyclable and remained the original catalytic water splitting performance within 20 h. The modification of Co3O4 and Pt improved the separation and migration of e- and h+, and induced the increased hydrogen evolution rate of g-C3N4.
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Parafusos Pediculares , Fusão Vertebral , Espondilolistese , Tuberculose , Humanos , Estudos RetrospectivosRESUMO
Oriented TiO2 nanotubes, which are fabricated by anodic oxidation method, are prospective in photoelectrochemical analysis and sensors. In this work, Pt and IrO2 co-modified TiO2 nanotubes array was prepared via a two-step deposition process involving the photoreductive deposition of Pt and chemical deposition of IrO2 on the oriented TiO2 nanotubes. Due to the improved separation of photo-generated electrons and holes, Pt-IrO2 co-modified TiO2 nanotubes presented significantly higher PEC activity than pure TiO2 nanotubes or mono-modified TiO2 nanotubes. The PEC sensitivity of Pt-IrO2 co-modified TiO2 nanotubes for glutathione was also monitored and good sensitivity was observed.
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HIP-55 (HPK1 [hematopoietic progenitor kinase 1] -interacting protein of 55 kDa) contains an actin-depolymerizing factor homology (ADF-H) domain at the N-terminus and a src homology 3 (SH3) domain at the C-terminus, which plays an important role in the T cell receptor (TCR) and B-cell receptor (BCR) signaling and immune system. In our previous studies, HIP-55 was found to be highly expressed in several types of tumors and function as a novel oncogenic signaling hub that regulates tumor progression and metastasis through defined functional domains, actin-binding and SH3 modules. However, the wider functions and mechanisms of HIP-55 are still unclear. Here, multi-omic analysis revealed that one of the main biofunctions of HIP-55 is the regulation of cytokines release. Furthermore, to investigate the role of HIP-55 in the cytokine production, a series Cytokine Antibody Arrays were performed to detect differentially expressed cytokines between control and HIP-55 knockdown cells. A total of 97 differentially expressed cytokines were identified from 300 cytokines in A549 cell. Bioinformatics analysis showed these differentially cytokines were mainly enriched in cancer signal pathways and IL-6 is the most critical hub in the integrated network. Analysis of RNAseq data from lung cancer patients showed that there is a strong negative correlation between HIP-55 and interleukin-6 (IL-6) in samples from lung adenocarcinoma patients. Our data indicated that HIP-55 may participate in cancer progression and metastasis via regulating cytokines release.
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Citocinas/metabolismo , Proteínas dos Microfilamentos/metabolismo , Proteínas dos Microfilamentos/fisiologia , Domínios de Homologia de src/fisiologia , Células A549 , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Biologia Computacional/métodos , Citocinas/imunologia , Técnicas de Silenciamento de Genes/métodos , Humanos , Interleucina-6/imunologia , Proteínas dos Microfilamentos/genética , Fosforilação , Ligação Proteica , Transdução de Sinais/imunologia , Domínios de Homologia de src/genéticaRESUMO
Glucose oxidase (GOx) based biosensors are commercialized and marketed for the high selectivity of GOx. Incorporation nanomaterials with GOx can increase the sensitivity performance. In this work, an enzyme glucose biosensor based on nanotubes was fabricated. By using Ti foil as a carrier, hydrogen titanate nanotubes (HTNTs), which present fine 3D structure with vast pores, were fabricated in-situ by the hydrothermal treatment. The multilayer nanotubes are open-ended with a diameter of 10 nm. Then glucose oxidase (GOx) was loaded on the nanotubes by cross-linking to form an electrode of the amperometric glucose biosensor (GOx/HTNTs/Ti electrode). The fabricated GOx/HTNTs/Ti electrode had a linear response to 1-10 mM glucose, and the response time was 1.5 s. The sensitivity of the biosensor was 1.541 µA·mM-1·cm-2, and the detection limit (S/N = 3) was 59 µM. Obtained results indicate that the in-situ fabrication and unique 3D structure of GOx/HTNTs/Ti electrode are beneficial for its sensitivity.
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Técnicas Biossensoriais/métodos , Glucose Oxidase/metabolismo , Glucose/análise , Hidrogênio/química , Imageamento Tridimensional , Nanotubos de Carbono/química , Titânio/química , Eletroquímica , Espectroscopia Fotoeletrônica , Propriedades de Superfície , Fatores de Tempo , Difração de Raios XRESUMO
QYR301, a novel herbicidal inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD), has great potential for resistant weed control in paddy fields, but massive use of pesticides may result in toxicity to soil non-target organisms. Thus, this study was designed to assess subchronic toxicity of different doses of QYR301 in artificial soil (0, 0.1, 1.0, 2.5, and 5.0 mg kg-1) to earthworms (Eisenia fetida) on days 7, 14, 21, and 28 after exposure, using biomarkers of reactive oxygen species (ROS) and malondialdehyde (MDA) contents, activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and glutathione-S-transferase (GST), and DNA damage. The ROS content significantly increased for all treatments on 7 and 14 days then decreased, and recovered to control level for 0.1 and 1.0 mg kg-1 treatment on day 28. Concerning enzymes activities, QYR301 increased POD, SOD, and GST activities, but inhibited CAT activity. Except for POD activity, SOD, CAT, and GST activities of 0.1 mg kg-1 group recovered to control level on day 28. Also, the MDA content of 0.1 mg kg-1 group reached control level on day 28. However, DNA damage was observed for all treatments throughout the experiment and it increased with increasing doses and time except for 5.0 mg kg-1 treatment on day 28. These results suggested that QYR301 induced excessive ROS production leading to oxidative stress in earthworms, which caused lipid membrane peroxidation and DNA damage ultimately. The findings could provide a theoretical foundation for assessing ecological damage of QYR301 to soils and a guide for future QYR301 applications.
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Ésteres/toxicidade , Herbicidas/toxicidade , Oligoquetos/fisiologia , Pirazóis/toxicidade , Animais , Biomarcadores , Catalase/metabolismo , Dano ao DNA , Inibidores Enzimáticos/toxicidade , Glutationa Transferase/metabolismo , Malondialdeído , Oligoquetos/metabolismo , Estresse Oxidativo , Peroxidase/metabolismo , Espécies Reativas de Oxigênio , Solo , Poluentes do Solo/toxicidade , Superóxido Dismutase/metabolismoRESUMO
Flower-like hydrogen titanate nanosheets were prepared by a hydrothermal method and an assembling process. Then the Pt nanoparticles as cocatalysts were supported on the hydrogen titanate nanosheets through a photoreduction method. The samples were characterized by XRD, TG-DTA, ICP, SEM, TEM, XPS and UV-vis DRS. Their photocatalytic activity for H2 production was also evaluated. The TEM results revealed that the as-prepared H2Ti2O5·H2O was with flower-like structure in which nanosheets were interlaced together. The formation mechanism of flower-like H2Ti2O5·H2O nanosheets was briefly proposed. With Pt cocatalyst, the flower-like H2Ti2O5·H2O had better photocatalytic activity (hydrogen production rate: 9.28 mmol g-1 h-1) and good cycling stability than original H2Ti2O5·H2O and commercial P25 under the same conditions. It was also found that the amount of cocatalyst Pt was positively correlated with photocatalytic performance.
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The gold catalysts supported on various morphologies of α-Fe2O3 in carbon monoxide (CO) oxidation reaction have been studied for many researchers. However, how to improve the catalytic activity and thermal stability for CO oxidation is still important. In this work, an unusual morphology of α-Fe2O3 was prepared by hydrothermal method and gold nanoparticles were supported using a deposition-precipitation method. Au/α-Fe2O3 catalyst exhibited great activity for CO oxidation. The crystal structure and microstructure images of α-Fe2O3 were carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and the size of gold nanoparticles was determined by transmission electron microscopy (TEM). X-ray photoelectron spectra (XPS) and Fourier transform infrared spectra (FTIR) results confirmed that the state of gold was metallic. The 1.86% Au/α-Fe2O3 catalyst calcined at 300 °C had the best catalytic performance for CO oxidation reaction and the mechanism for CO oxidation reaction was also discussed. It is highly likely that the small size of gold nanoparticle, oxygen vacancies and active sites played the decisive roles in CO oxidation reaction.
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Gold catalysts have been studied in-depth due to their unique activities for catalytic CO oxidation. Supports have intrinsic motivation for the high activity of gold catalysts. Thermally stable urchin-like CuO microspheres, which are potential support for gold catalysts, were prepared by facile solution-method. Then gold nanoparticles were loaded on them by deposition-precipitation method. The obtained gold catalysts were characterized by SEM, XRD, TEM, BET, ICP, and XPS. Their catalytic activity for CO oxidation was also evaluated. TEM results revealed that the gold nanoparticles with small sizes were highly distributed on the CuO surface in Au1.0/CuO-300. XPS observations demonstrated that the gold species in Au1.0/CuO-300 was of metallic state. Among the as-prepared catalysts, the Au1.0/CuO-300 catalyst displayed the best performance for CO oxidation and achieved 100% CO oxidation at 80 °C. It kept 100% conversion for 20 h at a reaction temperature of 180 °C, and showed good reusability after three reaction-cycles. The possible catalytic mechanism of Au1.0/CuO-300 catalyst for CO oxidation was also briefly proposed.
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Here, a heterogeneous Bacillus cereus (B. cereus) biofilm on the surface of 316 L stainless steel (SS) was observed. With electrochemical measurement and surface analysis, it was found that B. cereus biofilm could inhibit SS pitting corrosion, attributing to the blocking effect of bacterial biofilm on extracellular electron transfer (EET). Differential pulse voltammetry (DPV) and cyclic voltammetry (CV) results also showed that B. cereus biofilm clearly impeded the EET. The proposed mechanism for the decreased corrosion rates of SS involves the interactions of extracellular polymeric substance (EPS) with SS and biofilm formation blocking electron transfer, preventing the passive layer from destroying. After biofilm formation following initial attachment of cells and EPS, electron transfer between SS and the cathodic depolarizer (oxygen) was hindered.