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1.
J Phys Chem Lett ; 15(21): 5728-5737, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38771736

RESUMO

Nitrogen-doped carbon dots (NCDs) featuring primary pyrrolic N and pyridinic N dominated configurations were prepared using hydrothermal (H-NCDs) and microwave (M-NCDs) methods, respectively. These H-NCDs and M-NCDs were subsequently applied to decorate CsPbBr3 nanocrystals (CPB NCs) individually, using a ligand-assisted reprecipitation process. Both CPB/M-NCDs and CPB/H-NCDs nanoheterostructures (NHSs) exhibited S-scheme charge transfer behavior, which enhanced their performance in photocatalytic CO2 reduction and selectivity of CO2-to-CH4 conversion, compared to pristine CPB NCs. The presence of pyrrolic N configuration at the heterojunction of CPB/H-NCDs facilitated efficient S-scheme charge transfer, leading to a remarkable 43-fold increase in photoactivity. In contrast, CPB/M-NCDs showed only a modest 3-fold enhancement in photoactivity, which was attributed to electron trapping by pyridinic N at the heterojunction. The study offers crucial insights into charge carrier dynamics within perovskite/carbon NHSs at the molecular level to advance the understanding of solar fuel generation.

2.
Chemosphere ; 341: 140118, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37690552

RESUMO

To maintain a comfortable and healthy indoor environment without large amounts of energy consumption is of great importance. The progress of multifunctional indoor coatings with formaldehyde photodegradation and humidity buffering capability is necessary. From the viewpoints of circular economy, the preparation of effective photocatalysts (denoted as sFCC/GCN-x and ESF/GCN-y) via the decoration of recycling industrial wastes (i.e., spent fluid catalytic cracking catalysts (sFCC) and enhancement silica fume (ESF)) onto graphitic carbon nitride (GCN) by using a simple route is reported. The obtained results show that the prepared sFCC/GCN-0.15 and ESF/GCN-0.15 photocatalysts have the rate constants of formaldehyde degradation of 0.0075 and 0.0082 min-1, respectively, which are superior to that of pristine GCN (0.0044 min-1) under visible-light irradiation. The enhanced transfer kinetics of photogenerated electrons and declined recombination of electron-hole pairs may account for the surpassing photocatalytic performance. Results obtained from electron paramagnetic resonance spectra and Mott-Schottky plots indicate that the formation of ï½¥O2- via the reaction of O2 with electrons generated on the conduction band is the major reaction pathway to photodegrade formaldehyde under visible light. To further assess the real applications of prepared photocatalysts, the sFCC/GCN-0.15 and ESF/GCN-0.15 are used to fabricate the multifunctional coatings (denoted as s- and E-coatings) with sFCC and ESF as the main compositions. Experimentally, the E-coatings could reach the formaldehyde degradation efficiency of ca. 84.5% after 3 h of visible light irradiation and excellent humidity buffering ability (293.8 g m-2) which is at least 10-folds higher than commercial coatings (28.9 g m-2). This notable progress of humidity buffering capacity on E-coatings can be attributed to their surface textural properties. Most importantly, this study exemplifies the valorization of inorganic silica wastes to produce sustainable and multifunctional coatings which may offer the practical and cost-effective applications in the indoor living space.


Assuntos
Formaldeído , Catálise , Gases , Umidade , Fotólise
3.
Front Vet Sci ; 10: 1109947, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37152685

RESUMO

Background: As a natural host of Fasciola gigantica, buffalo is widely infected by F. gigantica. Its impact on buffalo production has caused great losses to the husbandry sector, and repeat infection is non-negligible. In buffaloes experimentally infected with F. gigantica, primary and secondary infection have yielded the same rate of fluke recovery, indicating a high susceptibility of buffalo to F. gigantica, which contributes to the high infection rate. Determining the immunological mechanism of susceptibility will deepen the understanding of the interaction between F. gigantica and buffalo. Here, we explored the immune response of buffaloes against primary and secondary F. gigantica infection, with a focus on cytokines' dynamics explored through serum cytokine detection. Methods: Buffaloes were assigned to three groups: group A (noninfected, n = 4), group B (primary infection, n = 3), and group C (secondary infection, n = 3). Group B was infected via oral gavage with 250 viable F. gigantica metacercariae, and group C was infected twice with 250 metacercariae at an interval of 4 weeks. The second infection of group C was performed simultaneously with that of group B. Whole blood samples were collected pre-infection (0 weeks) and at 1-6, 10, and 12 weeks after that. The serum levels of seven cytokines (IFN-γ, IL-4, IL-5, IL-10, IL-13, TGF-ß, and IL-17) were simultaneously determined using ELISA and further analyzed. Results: In the present study, no significant changes in Th1-type cytokines production were detected in early infection, both in primary and secondary infections, while the Th2-type response was strongly induced. A comparison of primary and secondary infection showed no significant difference in the cytokine secretion, which may indicate that the re-infection at 4 weeks after primary infection could not induce a robust adaptive immune response. The full extent of interaction between buffalo and F. gigantica in re-infection requires further study.

4.
J Phys Chem Lett ; 14(1): 122-131, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36574643

RESUMO

The photon energy-dependent selectivity of photocatalytic CO2-to-CO conversion by CsPbBr3 nanocrystals (NCs) and CsPbBr3/g-C3N4 nanoheterostructures (NHSs) was demonstrated for the first time. The surficial capping ligands of CsPbBr3 NCs would adsorb CO2, resulting in the carboxyl intermediate to process the CO2-to-CO conversion via carbene pathways. The type-II energy band structure at the heterojunction of CsPbBr3/g-C3N4 NHSs would separate the charge carriers, promoting the efficiency in photocatalytic CO2-to-CO conversion. The electron consumption rate of CO2-to-CO conversion for CsPbBr3/g-C3N4 NHSs was found to intensively depend on the rate constant of interfacial hole transfer from CsPbBr3 to g-C3N4. An in situ transient absorption spectroscopy investigation revealed that the half-life time of photoexcited electrons in optimized CsPbBr3/g-C3N4 NHS was extended two times more than that in the CsPbBr3 NCs, resulting in the higher probability of charge carriers to carry out the CO2-to-CO conversion. The current work presents important and novel insights of semiconductor NHSs for solar energy-driven CO2 conversion.

5.
Chemosphere ; 307(Pt 3): 135984, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35964722

RESUMO

Cu2O nanoparticles are decorated with biochars derived from spent coffee grounds (denoted as Cu2O/SCG) and applied as visible-light-active photocatalysts in the sulfamethoxazole (SMX) degradation. The physicochemical properties of Cu2O/SCG are identified by various spectral analysis, electrochemical and photochemical techniques. As a result, the Cu2O/SCG exhibits the higher removal efficiency of SMX than the pristine Cu2O under visible light irradiation. We can observe that Cu2O could be incorporated onto the SCG biochars with rich oxygen vacancies/adsorbed hydroxyl groups. In addition, the Cu2O/SCG has the lower charge transfer resistance, faster interfacial electron transfer kinetics, decreased recombination of charge carriers and superior absorbance of visible light. The construction of band diagrams for Cu2O/SCG and pristine Cu2O via UV-vis spectra and Mott-Schottky plots suggest that the band energy shifts and higher carrier density of Cu2O/SCG may be responsible for the photocatalytic activity enhancements. From the radical scavenger experiments and electron paramagnetic resonance spectra, the aforementioned energy shifts could decrease the energy requirement of transferring photoinduced electrons to the potential for the formation of active superoxide radicals (·O2-) via one and two-electron reduction routes in the photocatalytic reaction. A proposed degradation pathway shows that ·O2- and h+ are two main active species which can efficiently degrade SMX into reaction intermediates by oxidation, hydroxylation, and ring opening. This research demonstrates the alternative replacement of conventional carbon materials for the preparation of biochar-assisted Cu2O photocatalysts which are applied in the environmental decontamination by using solar energy.


Assuntos
Sulfametoxazol , Superóxidos , Carbono , Carvão Vegetal , Café , Luz , Oxigênio , Fotólise , Sulfametoxazol/química
6.
Front Microbiol ; 13: 1089394, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36620027

RESUMO

Introduction: Widespread Fasciola gigantica infection in buffaloes has caused great economic losses in buffalo farming. Studies on F. gigantica excretory and secretory products (FgESP) have highlighted their importance in F. gigantica parasitism and their potential in vaccine development. Identifying FgESP components involved in F. gigantica-buffalo interactions during different periods is important for developing effective strategies against fasciolosis. Methods: Buffaloes were assigned to non-infection (n = 3, as control group) and infection (n = 3) groups. The infection group was orally administrated 250 metacercariae. Sera were collected at 3, 10, and 16 weeks post-infection (wpi) for the non-infection group and at 0 (pre-infection), 1, 3, 6, 8, 10, 13, and 16 wpi for the infection group. FgESP components interacting with sera from the non-infection and infection groups assay were pulled down by co-IP and identified using LC-MS/MS. Interacting FgESP components in infection group were subjected to Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway and gene ontology (GO) functional annotation to infer their potential functions. Results and discussion: Proteins of FgESP components identified in the non-infection group at 3, 10, and 16 wpi accounted for 80.5%, 84.3%, and 82.1% of all proteins identified in these three time points, respectively, indicating surroundings did not affect buffalo immune response during maintenance. Four hundred and ninety proteins were identified in the infection group, of which 87 were consistently identified at 7 time points. Following GO analysis showed that most of these 87 proteins were in biological processes, while KEGG analysis showed they mainly functioned in metabolism and cellular processing, some of which were thought to functions throughout the infection process. The numbers of specific interactors identified for each week were 1 (n = 12), 3 (n = 5), 6 (n = 8), 8 (n = 15), 10 (n = 23), 13 (n = 22), and 16 (n = 14) wpi, some of which were thought to functions in specific infection process. This study screened the antigenic targets in FgESP during a dense time course over a long period. These findings may enhance the understanding of molecular F. gigantica-buffalo interactions and help identify new potential vaccine and drug target candidates.

7.
J Colloid Interface Sci ; 592: 416-429, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33691223

RESUMO

Aerobic oxidation of 5-Hydroxymethylfurfural (HMF) to 2,5-Diformylfuran (DFF) using O2 gas represents a sustainable approach for valorization of lignocellulosic compounds. As manganese dioxide (MnO2) is validated as a useful oxidation catalyst and many crystalline forms of MnO2 exist, it is critical to explore how the crystalline structures of MnO2 influence their physical/chemical properties, which, in turn, determine catalytic activities of MnO2 crystals for HMF oxidation to DFF. In particular, six MnO2 crystals, α-MnO2, ß-MnO2, γ-MnO2, δ-MnO2, ε-MnO2, and λ-MnO2 are prepared and investigated for their catalytic activities for HMF oxidation to DFF. With different morphologies and crystalline structures, these MnO2 crystals possess very distinct surficial chemistry, redox capabilities, and textural properties, making these MnO2 exhibit different catalytic activities towards HMF conversion. Especially, ß-MnO2 can produce much higher DFF per surface area than other MnO2 crystals. ß-MnO2 could achieve the highest CHMF = 99% and YDFF = 97%, which are much higher than the reported values in literature, possibly because the surficial reactivity of ß-MnO2 appears to be highest in comparison to other MnO2 crystals. Especially, ß-MnO2 could exhibit YDFF > 90% over 5 cycles of reusability test, and maintain its crystalline structure, revealing its advantageous feature for aerobic oxidation of HMF to DFF. Through this study, the relationship between morphology, surface chemistry, and catalytic activity of MnO2 with different crystal forms is elucidated for providing scientific insights into design, application and development of MnO2-based materials for aerobic oxidation of bio-derived molecules to value-added products.

8.
Zhong Yao Cai ; 31(3): 410-2, 2008 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-18619250

RESUMO

OBJECTIVE: To study the effects of HuDan Granules on lipid metabolism and antioxidant activity of mice with hyperlipidemia. METHODS: Seventy-eight mice were divided into six groups randomly: the normal control group, hyperlipemia group, HuDan Granules high, middle, low dose group and the Simvastatin group. Besides the normal control group, all the mice in the other groups were fed with lipid emulsion for 4 weeks. The Chinese medicine groups were treated with HuDan Granules at the dose of 12,6,3 g/kg, the normal control group and hyperlipemia group were treated with normal sodium, the Simvastatin group were treated with Simvastatin. After 4 weeks, the TC, TG, HDL-C, LDL-C, SOD, GSH-Px and LPO in serum were measured. RESULTS: HuDan Granules groups could significantly decrease the serum TC, TG, HDL-C in the experimental hyperlipidemia mice, and markedly increase the level of serum HDL-C. Mean level of serum LPO in the experimental groups treated by HuDan Granules at different dosages were much lower than that in hyperlipidemia group (P<0.05), but higher than the Simvastatin group (P<0.05). And the SOD and GSH-Px activities of serum in the group of HuDan Granules were much higher than those in hyperlipidemia group and the Simvastatin group (P<0.05). CONCLUSION: HuDan Granules can regulate lipid metabolism, enhance the antioxidation and reduce the lipid peroxidation in mice with hyperlipidemia.


Assuntos
Antioxidantes/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Hiperlipidemias/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Antioxidantes/uso terapêutico , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Quimioterapia Combinada , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Hiperlipidemias/sangue , Hiperlipidemias/metabolismo , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Fitoterapia , Distribuição Aleatória , Sinvastatina/farmacologia , Sinvastatina/uso terapêutico , Superóxido Dismutase/sangue , Triglicerídeos/sangue
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