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1.
Opt Express ; 32(7): 12428-12437, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571065

RESUMO

The challenges presented by the directly reflected field in optical feedback cavity-enhanced spectroscopy systems serve as substantial obstacles, introducing additional complexity to existing systems and compromising their sensitivity, as the underlying mechanisms of its adverse effects remain not fully understood. This study aims to address this issue by introducing a comprehensive analytical model. Additionally, frequency locking can be achieved by decreasing the feedback rate, the laser's linewidth enhancement factor, and the directly reflected field, and by increasing the refractive index of the gain medium, the length of the laser's resonant cavity, the electric field reflectivity of the laser's output facet, and the resonant field. These parameters can affect the feedback coupling rate pre-factor, and for a resonant cavity with a length of 0.394 m, optical feedback can only be established when the feedback coupling rate pre-factor is less than 1.05 × 109. Through experimental validation, we successfully confirm the effectiveness of the proposed solution in eliminating the detrimental effects of the directly reflected field. Importantly, this suppression is achieved without compromising other aspects of the system's performance. The research findings not only offer the potential to optimize various cavity-enhanced spectroscopy systems that rely on optical feedback but also show promising applications in advancing the development of high-purity spectrum diode lasers utilizing optical feedback from an external high-finesse cavity.

2.
Cancer Cell Int ; 24(1): 168, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734657

RESUMO

BACKGROUND: "Disulfide death," a form of cellular demise, is triggered by the abnormal accumulation of intracellular disulfides under conditions of glucose deprivation. However, its role in the prognosis of glioma remains undetermined. Therefore, the main objective of this study is to establish prognostic signature based on disulfide death-related genes (DDRGs) and to provide new solutions in choosing the effective treatment of glioma. METHODS: The RNA transcriptome, clinical information, and mutation data of glioma samples were sourced from The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA), while normal samples were obtained from the Genotype-Tissue Expression (GTEx). DDRGs were compiled from previous studies and selected through differential analysis and univariate Cox regression analysis. The molecular subtypes were determined through consensus clustering analysis. Further, LASSO analysis was employed to select characteristic genes, and subsequently, a risk model comprising seven DDRGs was constructed based on multivariable Cox analysis. Kaplan-Meier survival curves were employed to assess survival differences between high and low-risk groups. Additionally, functional analyses (GO, KEGG, GSEA) were conducted to explore the potential biological functions and signaling pathways of genes associated with the model. The study also explored immune checkpoint (ICP) genes, immune cell infiltration levels, and immune stromal scores. Finally, the effect of Importin-4(IPO4) on glioma has been further confirmed through RT-qPCR, Western blot, and cell functional experiments. RESULTS: 7 genes associated with disulfide death were obtained and two subgroups of patients with different prognosis and clinical characteristics were identified. Risk signature was subsequently developed and proved to serve as an prognostic predictor. Notably, the high-risk group exhibited an immunosuppressive microenvironment characterized by a high concentration of M2 macrophages and regulatory T cells (Tregs). In contrast, the low-risk group showed lower half-maximal inhibitory concentration (IC50) values. Therefore, patients in the high-risk group may benefit more from immunotherapy, while patients in the low-risk group may benefit more from chemotherapy. In addition, in vitro experiments have shown that inhibition of the expression of IPO4 leads to a significant reduction in the proliferation, migration, and invasion of glioma cells. CONCLUSION: This study identified two glioma subtypes and constructed a prognostic signature based on DDRGs. The signature has the potential to optimize the selection of patients for immune- and chemotherapy and provided a potential therapeutic target for glioma.

3.
Cancer Cell Int ; 24(1): 229, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951882

RESUMO

Small extracellular vesicles (sEVs) are cell-derived, nanometer-sized particles enclosed by a lipid bilayer. All kinds of biological molecules, including proteins, DNA fragments, RNA, lipids, and metabolites, can be selectively loaded into sEVs and transmitted to recipient cells that are near and distant. Growing shreds of evidence show the significant biological function and the clinical significance of sEVs in cancers. Numerous recent studies have validated that sEVs play an important role in tumor progression and can be utilized to diagnose, stage, grading, and monitor early tumors. In addition, sEVs have also served as drug delivery nanocarriers and cancer vaccines. Although it is still infancy, the field of basic and translational research based on sEVs has grown rapidly. In this review, we summarize the latest research on sEVs in gliomas, including their role in the malignant biological function of gliomas, and the potential of sEVs in non-invasive diagnostic and therapeutic approaches, i.e., as nanocarriers for drug or gene delivery and cancer vaccines.

4.
Hum Genomics ; 17(1): 33, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-37004060

RESUMO

BACKGROUND: Super-enhancers (SEs), driving high-level expression of genes with tumor-promoting functions, have been investigated recently. However, the roles of super-enhancer-associated lncRNAs (SE-lncRNAs) in tumors remain undetermined, especially in gliomas. We here established a SE-lncRNAs expression-based prognostic signature to choose the effective treatment of glioma and identify a novel therapeutic target. METHODS: Combined analysis of RNA sequencing (RNA-seq) data and ChIP sequencing (ChIP-seq) data of glioma patient-derived glioma stem cells (GSCs) screened SE-lncRNAs. Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA) datasets served to construct and validate SE-lncRNA prognostic signature. The immune profiles and potential immuno- and chemotherapies response prediction value of the signature were also explored. Moreover, we verified the epigenetic activation mechanism of LINC00945 via the ChIP assay, and its effect on glioma was determined by performing the functional assay and a mouse xenograft model. RESULTS: 6 SE-lncRNAs were obtained and identified three subgroups of glioma patients with different prognostic and clinical features. A risk signature was further constructed and demonstrated to be an independent prognostic factor. The high-risk group exhibited an immunosuppressive microenvironment and was higher enrichment of M2 macrophage, regulatory T cells (Tregs), and Cancer-associated fibroblasts (CAFs). Patients in the high-risk group were better candidates for immunotherapy and chemotherapeutics. The SE of LINC00945 was further verified via ChIP assay. Mechanistically, BRD4 may mediate epigenetic activation of LINC00945. Additionally, overexpression of LINC00945 promoted glioma cell proliferation, EMT, migration, and invasion in vitro and xenograft tumor formation in vivo. CONCLUSION: Our study constructed the first prognostic SE-lncRNA signature with the ability to optimize the choice of patients receiving immuno- and chemotherapies and provided a potential therapeutic target for glioma.


Assuntos
Glioma , RNA Longo não Codificante , Humanos , Animais , Camundongos , Prognóstico , RNA Longo não Codificante/genética , Proteínas Nucleares , Fatores de Transcrição , Glioma/genética , Modelos Animais de Doenças , Microambiente Tumoral/genética , Proteínas de Ciclo Celular
5.
Opt Express ; 30(20): 36394-36402, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36258568

RESUMO

We experimentally demonstrate an integrated visible light modulator at 532 nm on the thin-film lithium niobate platform. The waveguides on such platform feature a propagation loss of 2.2 dB/mm while a grating for fiber interface has a coupling loss of 5 dB. Our fabricated modulator demonstrates a low voltage-length product of 1.1 V·cm and a large electro-optic bandwidth with a roll-off of -1.59 dB at 25 GHz for a length of 3.3 mm. This device offers a compact and large bandwidth solution to the challenge of integrated visible wavelength modulation in lithium niobate and paves the way for future small-form-factor integrated systems at visible wavelengths.

6.
Cancer Biol Ther ; 25(1): 2338955, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38680092

RESUMO

Gliomas are the most common type of primary brain tumor. Despite advances in treatment, it remains one of the most aggressive and deadly tumor of the central nervous system (CNS). Gliomas are characterized by high malignancy, heterogeneity, invasiveness, and high resistance to radiotherapy and chemotherapy. It is urgent to find potential new molecular targets for glioma. The TRPM channels consist of TRPM1-TPRM8 and play a role in many cellular functions, including proliferation, migration, invasion, angiogenesis, etc. More and more studies have shown that TRPM channels can be used as new therapeutic targets for glioma. In this review, we first introduce the structure, activation patterns, and physiological functions of TRPM channels. Additionally, the pathological mechanism of glioma mediated by TRPM2, 3, 7, and 8 and the related signaling pathways are described. Finally, we discuss the therapeutic potential of targeting TRPM for glioma.


•TRPM channels are widely expressed in the human body and play an important role in gliomas.• Abnormal expression of TRPM2, 3, 7, and 8 channels in gliomas is associated with disease severity and prognosis.•TRPM2, 3, 7, and 8 channels are effective targets in glioma.


Assuntos
Neoplasias Encefálicas , Glioma , Canais de Cátion TRPM , Humanos , Glioma/metabolismo , Glioma/patologia , Glioma/genética , Glioma/tratamento farmacológico , Canais de Cátion TRPM/metabolismo , Canais de Cátion TRPM/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Transdução de Sinais , Animais
7.
Int J Biol Macromol ; 247: 125829, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37453634

RESUMO

The non-degradable traditional polyethylene (PE) mulch film has caused great harm to both the ecological environment as well as human health. Therefore, the biodegradable bone gelatin (B-Gel) was innovatively selected to build the mulch film. To further enhance the toughness of the B-Gel mulch films, a POSS star-shaped polymer/bone gelatin (P(POSS-AGE-HEA)/B-Gel) composite was prepared by introducing POSS star-shaped polymer into B-Gel via in situ polymerization using polyhedral oligomeric silsesquioxane (POSS), allyl glycidyl ether (AGE) and hydroxyethyl acrylate (HEA) as raw material, and then was cast to obtain the P(POSS-AGE-HEA)/B-Gel mulch film. The epoxy group of POSS star-shaped polymer with the -COOH and -NH2 of B-Gel forms a covalent bond, and the hydroxyl group with the active groups of B-Gel forms hydrogen bonds. Meanwhile, the multiple side chains of POSS star-shaped polymer are intertwined with B-Gel. These covalent and hydrogen bonds as sacrificial bonds for effective energy dissipation giving the bone gelatin-based film excellent mechanical properties with a tensile strength of 7.56 ± 0.64 MPa and elongation at break of 197.49 ± 17.63 %. Additionally, it also demonstrated sound water vapor barrier, surface hydrophobicity, light transmittance and the effect of facilitating the growth and germination ratio (93.75 %) of wheat.


Assuntos
Gelatina , Polímeros , Humanos , Polímeros/química , Resistência à Tração
8.
ISA Trans ; 136: 162-172, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36577623

RESUMO

This paper considers the finite time convergence problem of 2-D path following for fixed wing unmanned air vehicle. Firstly, the UAV path following model is divided into an outer guidance loop and an inner control loop. Then, the guidance loop and control loop controllers of the UAV are derived by global fast terminal sliding mode control technique, which is able to guarantee the system state variables converge to expected values in finite time and eliminate the chattering phenomenon caused by the switching control action. Furthermore, the stability of the two-loops system is proven by Lyapunov stability theory. Finally, the simulation results are shown to verify the performance of the proposed method.

9.
mSystems ; 8(1): e0083522, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36511708

RESUMO

Because antibiotics have been phased out of use in poultry feed, measures to improve intestinal health have been sought. Dietary fiber may be beneficial to intestinal health by modulating gut microbial composition, but the exact changes it induces remain unclear. In this study, we evaluated the effect of Flammulina velutipes stipe wastes (FVW) on the cecal microbiotas of laying chickens at ages spanning birth to 490 days. Using clonal sequencing and 16S rRNA high-throughput sequencing, we showed that FVW improved the microbial diversity when they under fluctuated. The evolvement of the microbiota enhanced the physiological development of laying hens. Supplementation of FVW enriched the relative abundance of Sutterella, Ruminiclostridium, Synergistes, Anaerostipes, and Rikenellaceae, strengthened the positive connection between Firmicutes and Bacteroidetes, and increased the concentration of short-chain fatty acids (SCFAs) in early life. FVW maintains gut microbiota homeostasis by regulating Th1, Th2, and Th17 balance and secretory IgA (S-IgA) level. In conclusion, we showed that FVW induces microbial changes that are potentially beneficial for intestinal immunity. IMPORTANCE Dietary fiber is popularly used in poultry farming to improve host health and metabolism. Microbial composition is known to be influenced by dietary fiber use, although the exact FVW-induced changes remain unclear. This study provided a first comparison of the effects of FVW and the most commonly used antibiotic growth promoter (flavomycin) on the cecal microbiotas of laying hens from birth to 490 days of age. We found that supplementation with FVW altered cecal microbial composition, thereby affecting the correlation network between members of the microbiota, and subsequently affecting the intestinal immune homeostasis.


Assuntos
Flammulina , Microbiota , Animais , Feminino , Dieta/veterinária , Galinhas , Estudos Longitudinais , RNA Ribossômico 16S/genética , Ração Animal/análise , Fibras na Dieta/farmacologia
10.
Poult Sci ; 102(1): 102261, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36410067

RESUMO

Egg production levels in late laying hens are negatively correlated with increasing age. Decreased liver and ovarian function in aging laying hens is accompanied by decreased antioxidant capacity, reproductive hormone levels, and follicular development, resulting in decreased synthesis of yolk precursors. The golden needle mushroom (Flammulina velutipes) has been reported to exhibit anti-inflammatory, antioxidant, and hypolipidemic properties. We aimed to reveal the therapeutic effects of F. velutipes stem (FVS) on liver-blood-ovary axis and investigate the underlying mechanisms. A total of 360 sixty-seven-wk-old laying hens were randomized into 4 treatment groups: 1) basal maize-soybean meal diet (CON); 2) basal maize + 20 g/kg FVS (2% FVS); 3) basal maize + 40 g/kg FVS (4% FVS); and 4) basal maize + 60 g/kg FVS (6% FVS). FVS groups demonstrated significantly increased egg production and ovarian development compared with the CON group. The addition of FVS increased the levels of antioxidant enzymes (GSH-Px, T-SOD, and T-AOC) in the liver, serum, and ovaries and decreased malondialdehyde levels by regulating the expression of proteins related to the Keap1-Nrf2/ARE signaling pathway. Additionally, FVS significantly decreased ovarian apoptosis by regulating Bax, Bcl-2, and caspase3 mRNA and protein expression levels. FVS significantly increased the expression levels of estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone and their respective receptors. With increased levels of estradiol transported to the liver through the bloodstream, targeted binding to estrogen receptor (ER)-α and ER-ß led to significant increases in ApoVLDL II, ApoB, and VTG II mRNA expression associated with yolk precursor synthesis. FVS decreased the levels of triglyceride and total cholesterol and significantly increased the expression of lipid metabolism, and transport-related mRNAs (FAS, PPAR-a/γ, and MTTP) in the liver. Therefore, the dietary supplementation of FVS can maintain the productive performance of aging laying hens by alleviating the degree of oxidative stress and regulating the transport of functional substances along the liver-blood-ovary axis, thereby improving the synthesis of yolk precursors.


Assuntos
Flammulina , Ovário , Feminino , Animais , Ovário/metabolismo , Antioxidantes/metabolismo , Flammulina/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Galinhas/fisiologia , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Dieta/veterinária , Fígado/metabolismo , Envelhecimento , Hormônio Luteinizante/metabolismo , Estradiol , Ração Animal/análise , Suplementos Nutricionais
11.
Chemosphere ; 329: 138657, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37040837

RESUMO

Owing to the high contents of organics and nitrogen in vacuum toilet wastewater (VTW) generated from high-speed trains, onsite pretreatment is usually required before VTW can be discharged into municipal sewers. In this study, a partial nitritation process was stably established in a sequential batch reactor to efficiently utilize the organics in synthetic and real VTWs for nitrogen removal and to produce an effluent suitable for anaerobic ammonia oxidation. In spite of the high fluctuations of COD and nitrogen in VTW, the organics used for nitrogen removal stabilized at 1.97 ± 0.18 mg COD mg N-1 removed, and the effluent NO2--N/NH4+-N ratios were maintained at 1.26 ± 0.13. The removal efficiencies of nitrogen and COD were 31.8 ± 3.5% and 65.2 ± 5.3% under the volumetric loading rates of 1.14 ± 0.15 kg N m-3 d-1 and 1.03 ± 0.26 kg COD m-3 d-1 for real VTW, respectively. Microbial community analysis revealed that Nitrosomonas (0.95%-1.71%) was the dominant autotrophic ammonium-oxidizing bacterial genus, but nitrite-oxidizing bacteria, Nitrolancea, was severely inhibited, with a relative abundance less than 0.05%. The relative abundance of denitrifying bacteria increased by 7.34% when the influent was switched to real VTW. Functional profile predictions of the biomass showed that the decrease in the COD/N ratio and the switch of reactor influent from synthetic to real VTW increased the relative abundance of enzymes and modules involved in carbon and nitrogen metabolisms.


Assuntos
Compostos de Amônio , Aparelho Sanitário , Águas Residuárias , Desnitrificação , Nitrogênio/metabolismo , Vácuo , Oxirredução , Reatores Biológicos/microbiologia , Bactérias/metabolismo , Esgotos/microbiologia
12.
Nanoscale ; 15(44): 17818-17824, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37668358

RESUMO

Reported herein is the facial synthesis, molecular structure, and catalysis of a Pt/Ag nanocluster costabilized by organic ligands of phosphines and inorganic ligands of chlorides. The nanocluster with molecular formula of [PtAg18(dppp)6Cl8](SbF6)2 has been obtained facilely by the one pot method. The structure of the cluster could be anatomized as the stabilizaiton of PtAg12-centered icosahedral core by the metalloligand of dppp-Ag-Cl, in which Cl- not only caps the surface Ag atoms but also binds the core and surface motifs. Featuring eight free electrons in its structure, the cluster exhibits high stability. More interestingly, the exposure of surface metal sites endows the cluster with counterintutively  high catalytic activity in hydrogenation reactions.

13.
Neural Regen Res ; 18(4): 913-921, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36204863

RESUMO

Successful establishment of reconnection between retinal ganglion cells and retinorecipient regions in the brain is critical to optic nerve regeneration. However, morphological assessments of retinorecipient regions are limited by the opacity of brain tissue. In this study, we used an innovative tissue cleaning technique combined with retrograde trans-synaptic viral tracing to observe changes in retinorecipient regions connected to retinal ganglion cells in mice after optic nerve injury. Specifically, we performed light-sheet imaging of whole brain tissue after a clearing process. We found that pseudorabies virus 724 (PRV724) mostly infected retinal ganglion cells, and that we could use it to retrogradely trace the retinorecipient regions in whole tissue-cleared brains. Unexpectedly, PRV724-traced neurons were more widely distributed compared with data from previous studies. We found that optic nerve injury could selectively modify projections from retinal ganglion cells in the hypothalamic paraventricular nucleus, intergeniculate leaflet, ventral lateral geniculate nucleus, central amygdala, basolateral amygdala, Edinger-Westphal nucleus, and oculomotor nucleus, but not the superior vestibular nucleus, red nucleus, locus coeruleus, gigantocellular reticular nucleus, or facial nerve nucleus. Our findings demonstrate that the tissue clearing technique, combined with retrograde trans-synaptic viral tracing, can be used to objectively and comprehensively evaluate changes in mouse retinorecipient regions that receive projections from retinal ganglion cells after optic nerve injury. Thus, our approach may be useful for future estimations of optic nerve injury and regeneration.

14.
Animals (Basel) ; 12(24)2022 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-36552494

RESUMO

The continuous ovulation of laying hens during the peak period is likely to cause oxidative stress, resulting in a reduction in the laying cycle over time. The aim of this study was to evaluate the antioxidant effects of Aronia melanocarpa (AM) in the diet and its effect on the yolk precursor content caused by ovulation in laying hens during the peak period. A total of 300 25-week-old Roman brown laying hens were randomly divided into five groups with six replicates in each group, 10 in each replicate. The control group was fed a basal diet, the positive control group was fed a Vitamin C (VC) plus basal diet, and the experimental group was fed 1%, 4%, and 7% doses of AM plus diet according to the principle of energy and nitrogen requirements, which lasted eight weeks. At the end of the study, the egg quality, biochemical, and antioxidant markers, as well as mRNA and protein expressions, were evaluated to determine the potential signaling pathways involved. Results showed that the addition of AM to the feed increased the weight of laying hens at the peak of egg production and improved egg quality. The biochemical markers, as well as the antioxidant parameters in the serum, liver, and ovarian tissues, were ameliorated. The gene and protein expression of recombinant kelch-like ECH-associated protein 1 (Keap1) in the liver and ovarian tissues was decreased, while nuclear factor erythroid-2 related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression was increased. The feed supplemented with AM also increased the estrogen contents and lipid parameters, as well as the gene and protein expressions related to the yolk precursor. Feed supplemented with AM could improve the egg quality and the oxidative stress caused by the ovulation process of laying hens during the peak egg production period by activating the Keap1/Nrf2 signaling pathway. These results suggest that the feed supplemented with 1% AM and 4% AM can improve egg production in peak laying hens.

15.
PLoS One ; 16(8): e0256904, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34464423

RESUMO

The 15-minute community life circle (15min-CLC) strategy is one of Shanghai's important methods for building a global city and facing a society with a more diverse population structure in the future. In the existing research, the balance between the construction of the life circle and the needs of the people in the life circle still needs to be further fulfilled. This paper is based on the city's multi-source large data set including 2018 AutoNavi POI (Point of Interests), OSM (OpenStreetMap) road network data and LandScan population data set, and evaluates the current status of Shanghai's 15min-CLC through the fusion of kernel density estimation, service area analysis and other statistical models and proposes relevant optimization suggestions. The results show that there are the following shortcomings: (1) From the perspective of different types of infrastructure service facilities, the spatial construction of Shanghai's overall life service facilities and shopping service facilities needs to be optimized. (2) From the perspective of comprehensive evaluation, the comprehensive service convenience of infrastructure service facilities in the downtown area is relatively high, while the comprehensive service convenience of urban infrastructure service facilities in the suburbs and outer suburbs is relatively low; The diversity of basic service facilities in the 15min-CLC in the downtown area is more consistent with the population distribution; However, in the peripheral areas of the urban area, too many infrastructure service facilities have been constructed. Based on the above shortcomings and the perspective of supply and demand matching, relevant optimization strategies are proposed in different regions and different types of infrastructure service facilities: (1) focus on the construction of basic service facilities in the urban fringe and urban-rural areas, improve the full coverage of the basic service facilities, and appropriately reduce the number of basic service facilities in the downtown area. (2) The development of community business models can be used to promote the development of new life service facilities and shopping service facilities. (3) Improve community medical institutions through facility function conversion, merger and reconstruction, etc. (4) Optimize the hierarchical basic service facility system and improve the population supporting facilities of basic service facilities in the 15min-CLC. This paper incorporates people's needs and concerns on the living environment into the 15min-CLC evaluation model, and uses Shanghai as an example to conduct research, summarizes the existing shortcomings, and proposes corresponding optimization strategies based on the matching of supply and demand. This article attempts to explore a replicable 15min-CLC planning model, so that it can be extended to the Yangtze River Delta urban agglomeration, to provide reference for further research on the 15min-CLC, and to promote urban construction under the concept of sustainable development.


Assuntos
Ambiente Construído , Planejamento de Cidades/métodos , Características de Residência , Reforma Urbana/métodos , Atividades Cotidianas , China , Cidades , Demografia , Humanos , Modelos Estatísticos , População Urbana
16.
Nanomaterials (Basel) ; 10(5)2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32455569

RESUMO

Functional metal organic framework (MOF) derivatives have attracted tremendous attention as promising catalysts for various reactions. The thermal decomposition strategies have a vital effect on the structures and physicochemical properties of functional MOF derivatives. Nevertheless, what effect does the pyrolysis strategy have on MOF derivatives need further study. In this work, one-step (under dry air) and two-step (first under N2 and then dry air) pyrolysis are chosen to prepare the functional ceria-based MOF derivatives with novel hierarchical pore structure. In comparison with the derivatives prepared by one-step pyrolysis, the two-step pyrolysis composites exhibit better catalytic activity for toluene oxidation due to the higher contents of surface absorbed oxygen species and surface oxygen vacancies. The reusability and durability test demonstrates perfect stability of such functional MOF derivatives. The in-situ UV Raman reveals that two-step strategy is favorable for enhancing the gaseous oxygen activation ability of the functional MOF derivatives. Those findings may instruct the synthesis of functional MOF derivatives via different pyrolysis strategies as well as afford a further understanding of the crucial role of oxygen vacancies.

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