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Confinement effects in highly porous nanostructures can effectively adjust the selectivity and kinetics of electrochemical reactions, which can boost the methanol oxidation reaction (MOR). In this work, carbonized ZIF-8-confined hollow PtCo nanospheres (PtCo@carbonized ZIF-8) were fabricated using a facile strategy. A monodisperse confined region was successfully prepared, and the dispersion of the PtCo nanoparticles (NPs) could be precisely regulated, allowing for the effective tuning of the confined region. Thus, the precise regulation of the catalytic reaction was achieved. Importantly, hollow PtCo NPs were prepared using a method based on the Kirkendall effect, and their forming mechanism was systematically investigated. Because of the confinement effects of carbonized zeolitic imidazolate framework-8 (ZIF-8), the crystal and electronic structures of the PtCo NPs were able to be effectively tuned. Our electrochemical results show that PtCo@carbonized ZIF-8 composites manifest a higher mass activity (1.4 A mgPt-1) and better stability compared to commercial Pt/C.
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Single-molecule magnets (SMMs) show wide potential applications in the field of ultrahigh-density storage materials, quantum computing, spintronics, and so on. Lanthanide (Ln) SMMs, as an important category of SMMs, open up a promising prospect due to their large magnetic moments and huge magnetic anisotropy. However, the construction of high performance for Ln SMMs remains an enormous challenge. Although remarkable advances are focused on the topic of Ln SMMs, the research on Ln SMMs with different nuclear numbers is still deficient. Therefore, this review summarizes the design strategies for the construction of Ln SMMs, as well as the metal skeleton types. Furthermore, we collect reported Ln SMMs with mononuclearity, dinuclearity, and multinuclearity (three or more Ln spin centers) and the SMM properties including energy barrier (Ueff ) and pre-exponential factor (τ0 ) are described. Finally, Ln SMMs with low-nuclearity SMMs, especially for single-ion magnets (SIMs), are highlighted to understand the correlations between structures and magnetic behavior of the detail SMM properties are described. We expect the review can shed light on the future developments of high-performance Ln SMMs.
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As we know, in plasmonic-enhanced heterogeneous catalysis, the reaction rates could be remarkably accelerated by generating hot carriers in the constituent nanostructured metals. To further improve the reaction rate, well-defined heterostructures based on plasmonic gold nanoparticles on MXene Ti3C2Tx nanosheets (Au NPs@Ti3C2Tx) were rationally designed and systematically investigated to improve the performance of the oxygen evolution reaction (OER). The results demonstrated that the catalysis performance of the Au NPs@Ti3C2Tx system could be easily tuned by simply varying the concentration and size of Au NPs, and Au NPs@Ti3C2Tx with an average Au NP diameter (â¼10 nm) exhibited a 2.5-fold increase in the oxidation or reduction current compared with pure Ti3C2Tx. The enhanced OER performance can be attributed to the synergistic effect of the plasmonic hot hole injection and Schottky junction carrier trapping. Owing to easy fabrication of Au NPs@Ti3C2Tx, the tunable size and concentration of Au NPs loaded on MXene nanosheets, and the significantly enhanced OER, it is expected that this work can lay the foundation to the design of multidimensional MXene-based heterostructures for highly efficient OER performance.
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MXene-based material has attracted wide attention due to its tunable band gap, high conductivity and impressive optical and plasmonic properties. Herein, a hetero-nanostructured water splitting system was developed based on N-doped Ti3 C2 (N10 TC) MXene and NiFe layered double hydroxide (LDH) nanosheets. The oxygen evolution reaction performance of the NiFe-LDH significantly enhanced to approximately 8.8-fold after incorporation of N10 TC. Meanwhile, the Tafel slope was only 58.1â mV dec-1 with light irradiation, which is lower than pure NiFe-LDH nanosheets (76.9â mV dec-1 ). All results manifested the vital role of the N10 TC MXene induced plasmonic hot carriers via electrophoto-excitation in enhancing the full water splitting performance of the as-prepared system. This work is expected to provide a platform for designing various plasmonic MXenes-based heterogeneous structures for highly efficient catalytic applications.
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PURPOSE: In recent years, traditional Chinese medicine has achieved good results in treating gliomas. This research aimed to reveal the effect of Shezhi Huangling decoction (SD) on glioma cell process. METHODS: U87 and U251 cells were treated with different concentrations (10, 30 and 50 µg/mL) of SD or transfected with miR-1298-5p mimic, inhibitor and siRNA targeting TGIF1. Cell proliferation, migration, invasion and apoptosis were detected. The expression of miR-1298-5p was measured by qRT-PCR, while TGIF1 expression was examined by immunohistochemical analysis and Western blot. RESULTS: SD treatment inhibited the proliferation, migration and invasion of glioma cells and induced the apoptosis. In addition, SD treatment induced the expression of miR-1298-5p in glioma cells. The low expression of miR-1298-5p was examined in glioma tissues and was significantly related to the high histological grade of glioma patients and predicted a poor prognosis. MiR-1298-5p directly targeted the 3'-UTR of transforming growth factor ß induced factor 1 (TGIF1) and reduced TGIF1 protein expression. MiR-1298-5p restricted the proliferation, migration and invasion of glioma cells and induced cell apoptosis by targeting TGIF1. CONCLUSION: Our data reveal that SD acts as a cancer-inhibiting agent in glioma via miR-1298-5p/TGIF1 axis, suggesting a potential therapeutic application of SD in glioma.
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It is widely known that the excellent intrinsic electronic and optoelectronic advantages of bismuthene and tellurene make them attractive for applications in transistors and logic and optoelectronic devices. However, their poor optoelectronic performances, such as photocurrent density and photoresponsivity, under ambient conditions severely hinder their practical application. To satisfy the demand of high-performance optoelectronic devices and topological insulators, bismuth telluride nanoplates (Bi2Te3 NPs) with different sizes, successfully synthesized by a solvothermal approach have been, for the first time, employed to fabricate a working electrode for photoelectrochemical (PEC)-type photodetection. It is demonstrated that the as-prepared Bi2Te3 NP-based photodetectors exhibit remarkably improved photocurrent density, enhanced photoresponsivity, and faster response time and recovery time in the UV-Vis region, compared to bismuthene and tellurene-based photodetectors. Additionally, the PEC stability measurements show that Bi2Te3 NPs have a comparable long-term stability for on/off switching behaviour for the bismuthene and tellurene-based photodetectors. Therefore, it is anticipated that the present work can provide fundamental acknowledgement of the optoelectronic performance of a PEC-type Bi2Te3 NP-based photodetector, shedding light on new designs of high-performance topological insulator-based optoelectronic devices.
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To further extend our understanding of the mechanism causing the current nearly extinct status of the baiji (Lipotes vexillifer), one of the most critically endangered species in the world, genetic diversity at the major histocompatibility complex (MHC) class II DRB locus was investigated in the baiji. Nine highly divergent DRB alleles were identified in 17 samples, with an average of 28.4 (13.2%) nucleotide difference and 16.7 (23.5%) amino acid difference between alleles. The unexpectedly high levels of DRB allelic diversity in the baiji may partly be attributable to its evolutionary adaptations to the freshwater environment which is regarded to have a higher parasite diversity compared to the marine environment. In addition, balancing selection was found to be the main mechanisms in generating sequence diversity at baiji DRB gene. Considerable sequence variation at the adaptive MHC genes despite of significant loss of neutral genetic variation in baiji genome might suggest that intense selection has overpowered random genetic drift as the main evolutionary forces, which further suggested that the critically endangered or nearly extinct status of the baiji is not an outcome of genetic collapse.
Assuntos
Golfinhos/genética , Espécies em Perigo de Extinção , Variação Genética , Antígenos de Histocompatibilidade Classe II/genética , Adaptação Fisiológica/genética , Alelos , Animais , Biodiversidade , China , Golfinhos/crescimento & desenvolvimento , Evolução Molecular , Extinção Biológica , Água Doce , Frequência do Gene , Deriva Genética , Genética Populacional , Geografia , Antígenos de Histocompatibilidade Classe II/classificação , Dados de Sequência Molecular , Filogenia , Água do Mar , Seleção Genética , Especificidade da EspécieRESUMO
The complete mitogenome sequence of the Chinese longsnout catfish Leiocassis longirostris was determined using long-polymerase chain reaction (long-PCR) and directly sequenced with primer walking method. The complete mtDNA was 16,534 bp in length and contained 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and a control region (D-loop), the gene composition/order of which was identical to that observed in most other vertebrates. Phylogenetic relationship of 15 ostariophysan fishes was reconstructed using Bayesian inference and maximum likelihood methods based on a total of 15,658 nucleotides from all the 13 protein-coding, two rRNA, and 22 tRNA genes, using recently developed models of rate autocorrelation, which resolved the phylogenetic relationship of the major ostariophysan lineages with a high statistical support. The present result was consistent with some previous molecular cladistic work which supported the grouping of (((((Characiformes, Gymnotiformes), Siluriformes), Cypriniformes), Gonorynchiformes), outgroup). The Chinese longsnout catfish together with the Bagrid catfish (both from the same family Bagridae) had a closer affinity with Amblycipitidae than with other four analyzed catfish families. The relaxed molecular clock method incorporated into the program BEAST vl.5.3 was used to estimate divergence dates among ostariophysan lineages, which revealed that the major ostariophysan lineages diversified in the middle Jurassic (around 164.5 million years ago (Mya)) and the split of Leiocassis/Pseudobagrus occurred in the Oligocene to Miocene (8.9-25.1 Mya). The time-calibrated tree generated in this study would provide a powerful evolutionary tool for broad-scale comparative studies of the catfishes and the ostariophysan fishes.
Assuntos
Peixes-Gato/genética , Genoma Mitocondrial/genética , Filogenia , Animais , Sequência de Bases , Teorema de Bayes , China , Primers do DNA/genética , Ordem dos Genes , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNARESUMO
There is considerable evidence that stilbenes provide health benefits. Trans-piceid is one of the major stilbenoid compounds in red wine and other plants. The purpose of this study is to investigate the metabolism of piceid in rats, including its conversion product by intestinal microflora in vitro and urinary metabolites. A HPLC-MS/MS method with electrospray ionization (ESI), negative ion mode and collision induced dissociation (CID), was used to elucidate the structures of the major metabolites of piceid. Three metabolites resveratrol, dihydropiceid and dihydroresveratrol were detected after incubating with gut microbiota for 5h. Four urinary metabolites of piceid were identified as resveratrol, dihydroresveratrol monosulfate, piceid monosulfate and piceid monoglucuronide.