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1.
Nat Commun ; 13(1): 2930, 2022 May 25.
Article in English | MEDLINE | ID: mdl-35614052

ABSTRACT

Methane (CH4) oxidation to high value chemicals under mild conditions through photocatalysis is a sustainable and appealing pathway, nevertheless confronting the critical issues regarding both conversion and selectivity. Herein, under visible irradiation (420 nm), the synergy of palladium (Pd) atom cocatalyst and oxygen vacancies (OVs) on In2O3 nanorods enables superior photocatalytic CH4 activation by O2. The optimized catalyst reaches ca. 100 µmol h-1 of C1 oxygenates, with a selectivity of primary products (CH3OH and CH3OOH) up to 82.5%. Mechanism investigation elucidates that such superior photocatalysis is induced by the dedicated function of Pd single atoms and oxygen vacancies on boosting hole and electron transfer, respectively. O2 is proven to be the only oxygen source for CH3OH production, while H2O acts as the promoter for efficient CH4 activation through ·OH production and facilitates product desorption as indicated by DFT modeling. This work thus provides new understandings on simultaneous regulation of both activity and selectivity by the synergy of single atom cocatalysts and oxygen vacancies.

2.
J Am Chem Soc ; 144(2): 740-750, 2022 Jan 19.
Article in English | MEDLINE | ID: mdl-34928583

ABSTRACT

Direct and efficient oxidation of methane to methanol and the related liquid oxygenates provides a promising pathway for sustainable chemical industry, while still remaining an ongoing challenge owing to the dilemma between methane activation and overoxidation. Here, ZnO with highly dispersed dual Au and Cu species as cocatalysts enables efficient and selective photocatalytic conversion of methane to methanol and one-carbon (C1) oxygenates using O2 as the oxidant operated at ambient temperature. The optimized AuCu-ZnO photocatalyst achieves up to 11225 µmol·g-1·h-1 of primary products (CH3OH and CH3OOH) and HCHO with a nearly 100% selectivity, resulting in a 14.1% apparent quantum yield at 365 nm, much higher than the previous best photocatalysts reported for methane conversion to oxygenates. In situ EPR and XPS disclose that Cu species serve as photoinduced electron mediators to promote O2 activation to •OOH, and simultaneously that Au is an efficient hole acceptor to enhance H2O oxidation to •OH, thus synergistically promoting charge separation and methane transformation. This work highlights the significances of co-modification with suitable dual cocatalysts on simultaneous regulation of activity and selectivity.

3.
J Hazard Mater ; 409: 124829, 2021 05 05.
Article in English | MEDLINE | ID: mdl-33422752

ABSTRACT

Alkyl quaternary ammonium-modified clay minerals, which are common environmentally friendly materials, have been widely studied and applied for the removal of pollutants. However, there are few reports on functionalizing the counterions to expand the application. In this study, the cationic gemini surfactant butane-1,4-bis(dodecyl dimethyl ammonium bromide) (gBDDA) and tetrachloroferrate (FeCl4-) are designed to modify montmorillonite (Mt), and the obtained FeCl4-/Gemini-Mt composite (FeOMt) is used for the removal of nitrate and/or phosphate from aqueous solution. The successful intercalation of gBDDA and favorable loading of FeCl4- into FeOMt are suggested by the characterization results of X-ray diffraction and Raman spectroscopy. Nitrate and/or phosphate are rapidly sequestered, and the respective maximum uptakes of 8.77 (N) and 28.1 (P) mg/g in the binary system are obtained. The phosphate uptake is stably maintained against many coexisting ions, but the nitrate uptake decreases with the increase in ionic strength. FeOMt is reusable and shows comparable uptake for nitrate and phosphate with respect to gBDDA-modified Mt and polymerized ferric chloride. Considering the multi-functionality and facile synthesis, FeOMt shows promising potential in the purification of wastewater contaminated simultaneously by poorly hydrated anions (e.g., ClO4-, TcO4-, etc.) and iron-selective anions (e.g., H2AsO4-, etc.).

4.
J BUON ; 25(4): 1821-1826, 2020.
Article in English | MEDLINE | ID: mdl-33099919

ABSTRACT

PURPOSE: Breast cancer is responsible for high morbidity and mortality across the globe. Studies are focusing to develop novel systemic therapies for the treatment of this disease. The present study was designed to examine the anticancer effects of Shionone against human breast cancer cells along with the underlying mechanism of its action. METHODS: The breast cancer SK-BR-3 and normal breast MB-157 cell lines were used in the study. CCK8 assay was used for cell viability assessment. DAPI was used for the assessment of nuclear morphology. Acridine orange (AO)/ ethidium bromide (EB) and annexin V/propidium iodide (PI) assays were used for detection of apoptosis. Cell cycle analysis was done by flow cytometry. Protein expression was examined by western blot analysis. RESULTS: The results showed that in vitro administration of Shionone led to decline of proliferation of breast cancer cells. The reduction of proliferative rates was attributed to the induction of apoptosis of breast cancer cells. Shionone caused cleavage of caspase-3 and 9. The expression of Bax was increased and that of Bcl-2 was decreased upon Shionone treatment. The transwell assays showed that Shionone suppressed the migration and invasion of breast cancer cells in a dose-dependent manner. Finally, western blot analysis showed that Shionone blocked the Ras/Raf/MEK/ERK and STAT3 signaling pathways in breast cancer cells. CONCLUSION: Taken all together, the study established the anticancer role of triterpenoid Shionone in restricting the growth and proliferation of human breast cancer cells.


Subject(s)
Breast Neoplasms/drug therapy , Cell Cycle Checkpoints/physiology , Flow Cytometry/methods , Medicine, Chinese Traditional/methods , Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors , STAT3 Transcription Factor/metabolism , Triterpenes/therapeutic use , Apoptosis , Cell Movement , Female , Humans , Neoplasm Invasiveness , Signal Transduction , Triterpenes/pharmacology
5.
BMC Vet Res ; 15(1): 60, 2019 Feb 13.
Article in English | MEDLINE | ID: mdl-30760271

ABSTRACT

BACKGROUND: Porcine circovirus type 3 (PCV3) is a single-stranded, closed circular DNA virus, which causes porcine dermatitis and nephropathy syndrome (PDNS), multisystemic inflammation, and reproductive failure. The present study aimed to investigate the seroprevalence of PCV3 in cattle (Bos taurus) in Shandong province, China, and examine its genome diversity. RESULTS: PCR amplification and sequencing showed that 74 of 213 bovine samples (34.7%) were positive for PCV3. Among them, the capsid gene (n = 12) and the complete genome (n = 4) were sequenced. These sequences had high identities to the reference capsid gene (98.0-100%) and the complete genome (97.5-99.8%). The PCV3 strains were classified into two different genotypes (PCV3a and PCV3b), according to phylogenetic analysis based on the complete genome and capsid gene sequences. Specifically, the bovine-origin strains in this study were grouped into PCV3a, showing a close relationship with PCV3-US/SD2016 (American strain; GenBank: KX966193.1). Notably, a comparison of the inferred amino acid sequences revealed a mutation from D124 to Y124. CONCLUSION: This was the first seroprevalence and genetic investigation of PCV3 in cattle in Shandong province, China. The results could provide insights into the epidemiology and pathogenesis of this important virus.


Subject(s)
Cattle Diseases/epidemiology , Circoviridae Infections/veterinary , Circovirus , Animals , Capsid Proteins/genetics , Cattle , Cattle Diseases/virology , China/epidemiology , Circoviridae Infections/epidemiology , Circovirus/genetics , Genome, Viral/genetics , Genotype , Phylogeny , Polymerase Chain Reaction/veterinary , Sequence Alignment/veterinary , Seroepidemiologic Studies
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