The promotion of magnetic field on catalytic performance has attracted extensive attention for a long time, and substantial improvements have been achieved in some catalysis fields. However, because the Zeeman energy is several orders of magnitude weaker, magnetic field seems unable to alter the band structure and has a negligible effect on semiconductor photocatalytic performance, which makes this task a great challenge. On the other hand, the spin-related behavior usually plays an important role in determining catalytic performance. For example, in some molecular catalysis, such as photosystem II, ferromagnetic alignment of the active material results in spin-oriented electrons, which are selected and accumulated at the interface, leading to great promotion of the oxygen evolution reaction activity. Here, we propose a magnetoresistance-related strategy to boost the carrier transfer efficiency and apply it in α-FeO/reduced graphene oxide hybrid nanostructures (α-FeO/rGO) to improve the photocatalytic performance under magnetic field. We show that both the degradation rate constant and photocurrent density of α-FeO/rGO can be dramatically enhanced with the application of magnetic field, indicating the promotion of the photocatalytic performance.
Porcine circovirus 3 (PCV3) is a novel virus associated with acute PDNS (porcine dermatitis and nephropathy syndrome)‐like clinical signs identified by metagenomic sequencing from swine. Its high occurrence may pose a potential threat to the swine industry worldwide. The processes resulting in the emergence and spread of PCV3 remain poorly understood. Herein, the possible origin, genotypes, and evolutionary dynamics of PCV3 based on available genomic sequences are determined. The closest ancestor of PCV3 is found to be within the clade 1 bat CVs. Using different phylogenetic methods, two major genotypes are identified, PCV3a and PCV3b. It is found that the effective population size of PCV3 increased rapidly during late 2013 to early 2014 and this is associated with the diversification of PCV3a and PCV3b. A relatively high effective reproductive number (Re) value and higher evolutionary rate were found compared to other single‐stranded DNA viruses, and positive selection on codons 122 and 320 (24 of ORF2) is identified. It is hypothesized that this, together with the prediction of a potential change of an antigenic epitope at position 320, might have allowed PCV3 to escape from the host immune response. Overall, this study has important implications for understanding the ongoing PCV3 cases worldwide and will guide future efforts to develop effective preventive and control measures.
Photodynamic
therapy (PDT), a clinically approved cancer treatment, has faced many
drawbacks that restricted its applications. For example, the hypoxia-induced
elevated hypoxia-inducible factor-1α (HIF-1α) may desensitize
tumors to PDT, and the high concentration of glutathione (GSH) in
cancer cells can also neutralize the generated reactive oxygen species
(ROS) during PDT, resulting in insufficient therapy. Moreover, extra
probes for imaging-guided visualization therapy are always needed
to track drug release or distribution, while it may decrease the drug
loading of the drug delivery system (DDS). In the present study, we
have designed and prepared a novel multifunctional combined therapy
nanoparticle (ZnPc@Cur-S-OA NPs), in which curcumin (Cur) was not
only used as a chemotherapy drug to achieve a combination therapy
with PDT via downregulating HIF-1α and depleting GSH in B16F10
cells but also designed as a small-molecule ROS-triggered release
prodrug to deliver the photosensitizer (PS). The red fluorescence
of PS in the nanoparticles (NPs) can be used to track the NPs distribution,
while the green fluorescence of Cur showed an “OFF–ON”
activation, which enables additional imaging and real-time self-monitoring
capabilities. These results proved that the prepared combined therapy
NPs were more effective to inhibit the growth of B16F10 mouse melanoma
tumor than was monotherapy without eliciting systemic toxicity either in vitro or in vivo, which indicated the
combined therapy NPs as an effective way to improve the PDT efficacy
via downregulation of HIF-1α and depletion of GSH. Thus, the
strategy of using a multifunctional natural product as the stimuli-responsive
carrier as well as the synergist with PDT for enhancing antitumor
efficacy via multiple pathways may open an alternative avenue to fabricate
new self-delivery combination therapy nanodrugs. Besides, the fluorescence
emitted from the drug can be used for real-time self-monitoring of
drug release and distribution, which has great potential in clinic
to adjust the administration dose and irradiation time for different
tumor types and stages for individual therapy.
Photocatalytic
CO2 conversion into carbonaceous fuels
through artificial photosynthesis is beneficial to global warming
mitigation and renewable resource generation. However, a high cost
is always required by special CO2-capturing devices for
efficient artificial photosynthesis. For achieving highly efficient
photocatalytic CO2 reduction (PCR) directly from natural
air, we report rose-like BiOCl that is rich in Bi vacancies (VBi) assembled by nanosheets with almost fully exposed active
{001} facets. These rose-like BiOCl with VBi assemblies
provide considerable adsorption and catalytic sites, which hoists
the CO2 capture and reduction capabilities, and thus expedites
the PCR to a superior value of 21.99 μmol·g–1·h–1 CO generation under a 300 W Xe lamp within
5 h from natural air. The novel design and construction of a photocatalyst
in this work could break through the conventional PCR system requiring
compression and purification for CO2, dramatically reduce
expenses, and open up new possibilities for the practical application
of artificial photosynthesis.
The electrocatalytic nitrogen oxidation reaction (NOR) is a promising alternative to the industrial synthesis of nitrate. However, with the enhancement of the NOR activity by modification methods, the competitive oxygen...
Meter-scale uniform g-CN nanorod (NR) arrays were directly grown on an FTO glass using an unprecedented vacuum magnetic filtered arc ion plating system for enhanced photoelectrochemical (PEC) performance. The construction of the g-CN film is based on the substrate deposition of the direct reaction of ionized carbon and nitrogen species, a gas-based bottom-up approach, distinctly different from the traditional powder deposition and thermal vapor pathways. The g-CN film exhibits obvious advantages over conventional ones in the application of PEC: (1) direct reaction of C and N species allows the formation of the g-CN without intralayer hydrogen bonds, which significantly reduces intralayer photogenerated charge carriers transfer resistance; (2) the g-CN exhibits the NR array structure and comprises considerably numerous layers stacking by stacking and vertically standing on the FTO substrate, which facilitates the photogenerated charges transfer and increases the contact area with electrolyte; (3) the robust mechanical strength of the g-CN NR film with the FTO substrate not only favors the effective charge transport but also allows long-term practical application against abrasion; (4) the gas-based bottom-up approach enables the g-CN to easily couple with, including but not limited to, TiO NR array to form heterostructures to further improve charge separation.
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