Abstract BiVO 4 ‐based photoanode is one of the most promising photoanodes for photoelectrocatalytic water splitting. However, the serious problem of interface charge recombination limits its further ...development. Here, a Mo:BiVO 4 /NiO x /CPF‐TCzB/NiCoBi photoanode is constructed with double hole transport layer and an energy level gradient to achieve an effective photo‐generated holes extraction and accumulation at the surface electrocatalyst. The conjugated polycarbazole framework CPF‐TCzB is used as hole transport layer to eliminate the charge recombination center between Mo:BiVO 4 and NiCoBi electrocatalyst and realize the extraction and storage of photo‐generated hole; NiO x nanoparticles are further inserted between Mo:BiVO 4 and CPF‐TCzB to form a gradient energy level, eliminating the energy level barrier and optimizing band alignment. As a result, Mo:BiVO 4 /NiO x /CPF‐TCzB/NiCoBi achieves a much higher photocurrent densities of 3.14 mA cm −2 than that of Mo:BiVO 4 (0.42 mA cm −2 ) at 0.6 V versus RHE. This work provides an specific way to adjust the band structure of BiVO 4 ‐based photoanodes and realize efficient hole extraction and storage for PEC water splitting.
BiVO4-based photoanode is one of the most promising photoanodes for photoelectrocatalytic water splitting. However, the serious problem of interface charge recombination limits its further ...development. Here, a Mo:BiVO4/NiOx/CPF-TCzB/NiCoBi photoanode is constructed with double hole transport layer and an energy level gradient to achieve an effective photo-generated holes extraction and accumulation at the surface electrocatalyst. The conjugated polycarbazole framework CPF-TCzB is used as hole transport layer to eliminate the charge recombination center between Mo:BiVO4 and NiCoBi electrocatalyst and realize the extraction and storage of photo-generated hole; NiOx nanoparticles are further inserted between Mo:BiVO4 and CPF-TCzB to form a gradient energy level, eliminating the energy level barrier and optimizing band alignment. As a result, Mo:BiVO4/NiOx/CPF-TCzB/NiCoBi achieves a much higher photocurrent densities of 3.14 mA cm-2 than that of Mo:BiVO4 (0.42 mA cm-2) at 0.6 V versus RHE. This work provides an specific way to adjust the band structure of BiVO4-based photoanodes and realize efficient hole extraction and storage for PEC water splitting.BiVO4-based photoanode is one of the most promising photoanodes for photoelectrocatalytic water splitting. However, the serious problem of interface charge recombination limits its further development. Here, a Mo:BiVO4/NiOx/CPF-TCzB/NiCoBi photoanode is constructed with double hole transport layer and an energy level gradient to achieve an effective photo-generated holes extraction and accumulation at the surface electrocatalyst. The conjugated polycarbazole framework CPF-TCzB is used as hole transport layer to eliminate the charge recombination center between Mo:BiVO4 and NiCoBi electrocatalyst and realize the extraction and storage of photo-generated hole; NiOx nanoparticles are further inserted between Mo:BiVO4 and CPF-TCzB to form a gradient energy level, eliminating the energy level barrier and optimizing band alignment. As a result, Mo:BiVO4/NiOx/CPF-TCzB/NiCoBi achieves a much higher photocurrent densities of 3.14 mA cm-2 than that of Mo:BiVO4 (0.42 mA cm-2) at 0.6 V versus RHE. This work provides an specific way to adjust the band structure of BiVO4-based photoanodes and realize efficient hole extraction and storage for PEC water splitting.
With the rapid development of human's exploitation of nature and animal husbandry, zoonoses have become a major public health problem worldwide. It is necessary to establish a rapid, specific and ...sensitive detection method to screen several zoonotic pathogenic bacteria simultaneously. In this study, phage display technology was used to screen specific peptide of three common zoonotic pathogens, E. coli O157:H7, L. monocytogenes and B. melitensis 16 M. Then, three peptide were obtained, named E2, L4 and B4, which can identify the three pathogens respectively. Three peptide modified with biotin were synthesized and were coupled to streptavidin magnetic beads (MBs) to form peptide-MBs, which enriched the above three pathogens from the samples. Three quantum dot (QD) probes were constructed by coupling three polyclonal antibodies to different fluorescent QD surfaces (QD540, QD580 and QD630). The simultaneous detection method based on peptide-MBs and QDs multicolor fluorescent labeling was established and could detect E. coli O157:H7, L. monocytogenes and B. melitensis 16 M simultaneously. The detection method took about 100 min with the detection limits of 103, 102 and 102 CFU/mL, respectively. The detection method could be also well utilized in real samples.
Display omitted
•Three peptides which could recognize E. coli O157:H7, L. monocytogenes and B. melitensis 16 M were screened successfully by phage display technology, with the advantages of good specificity, clear structure and low cost.•Peptide-MBs were utilized to enrich and separate pathogens in samples quickly and conveniently.•Multicolor fluorescent labeling of QDs have been successfully used for simultaneous detection of various pathogens.•The simultaneous fluorescence detection method was satisfactorily applied to the detection of zoonosis pathogens.
Theranostic tantalum oxide nanoparticles (TaO x NPs) of about 40 nm were successfully developed by conjugating functional molecules including polyethylene glycol (PEG), near-infrared (NIR) ...fluorescent dye, doxorubicin (DOX), and hyaluronic acid (HA) onto the surface of the nanoparticles (TaO x @Cy7-DOX-PEG-HA NPs) for actively targeting delivery, pH-responsive drug release, and NIR fluorescence/X-ray CT bimodal imaging. The obtained nanoagent exhibits good biocompatibility, high cumulative release rate in the acidic microenvironments, long blood circulation time, and superior tumor-targeting ability. Both in vitro and in vivo experiments show that it can serve as an excellent contrast agent to simultaneously enhance fluorescence imaging and CT imaging greatly. Most importantly, such a nanoagent could enhance the therapeutic efficacy of the tumor greatly and the tumor growth inhibition was evaluated to be 87.5%. In a word, multifunctional TaO x @Cy7-DOX-PEG-HA NPs can serve as a theranostic nanomedicine for fluorescence/X-ray CT bimodal imaging, remote-controlled therapeutics, enabling personalized detection, and treatment of cancer with high efficacy.
A novel, environmentally friendly, biomass-based modification technique utilizing carboxymethylation-activated alkali lignin (CAAL) and glutaraldehyde (GA) is proposed to enhance the physical and ...mechanical properties of poplar and fir wood. Water-soluble CAAL was prepared by modifying alkali lignin (AL) with sodium chloroacetate following low-temperature activation under a NaOH/urea system. AL is a biomass-based material from industrial by-products. As such, it does not rely on fossil resources nor emit volatile compounds that might limit its range of application. The successful preparation of CAAL was demonstrated by Fourier transform infrared spectroscopy (FTIR),
1
H nuclear magnetic resonance spectroscopy (NMR), and
13
C NMR, and the changes in structure were analyzed by 2D-heteronuclear singular quantum correlation (2D-HSQC),
31
P NMR, and gel permeation chromatography (GPC). The following characteristics of the modified wood samples were investigated in detail: weight percent gain (WPG), bulking, anti-swelling efficiency (ASE), water absorption rate (WAR), leachability of the modifier, microstructure, and mechanical properties. Water immersion results demonstrated that the CAAL/GA hybrid modifier enhanced ASE to 41.3% and 31.5% for fir and poplar, respectively, at a concentration of 15 wt.%. Furthermore, the WAR of fir was reduced by nearly three times to 30.7%, compared to that of a control sample treated solely with GA. GA-treated samples showed high brittleness, whereas both poplar and fir showed enhanced modulus of rupture and elasticity following treatment with the CAAL/GA hybrid modifier.
The conventional industrial production of nitrogen‐containing fertilizers, such as urea and ammonia, relies heavily on energy‐intensive processes, accounting for approximately 3 % of global annual ...CO2 emissions. Herein, we report a sustainable electrocatalytic approach that realizes direct and selective synthesis of urea and ammonia from co‐reduction of CO2 and nitrates under ambient conditions. With the assistance of a copper (Cu)‐based salphen organic catalyst, outstanding urea (3.64 mg h−1 mgcat−1) and ammonia (9.73 mg h−1 mgcat−1) yield rates are achieved, in addition to a remarkable Faradaic efficiency of 57.9±3 % for the former. This work proposes an appealing sustainable route to converting greenhouse gas and waste nitrates by renewable energies into value‐added fertilizers.
The electrosynthesis emerges as an appealing sustainable route to converting greenhouse gas (CO2) and waste nitrates by renewable energies into value‐added fertilizers. We demonstrate an organic Cu‐based salphen complex as an economic catalyst for efficient production of urea and ammonia. The improved performance by tuning functionalization of molecules provides an efficient and simple strategy for design of future electrocatalysts.
Water stress is a critical factor limiting the growth and development of Capsicum annuum. Flavonoids and lignin are important secondary metabolites that serve as signaling molecules in plant stress ...responses. However, the effects and regulatory mechanisms of lignin and flavonoids under water stress in Capsicum annuum remain unknown. The present study focused on the effects of drought and waterlogging stress on the morphology, hydrogen peroxide, and relative chlorophyll (SPAD), as well as enzyme activities, metabolite contents, and gene expression related to lignin and flavonoid metabolic pathways in Capsicum annuum. The results showed that drought and waterlogging stresses on the Capsicum annuum variety ‘Shuyu2’ significantly reduced plant height, stem thickness, and single-fruit weight, and increased fruit shape coefficients. Drought stress increased H2O2 and SPAD content, enhanced the activity levels of metabolic enzymes (phenylalanine deaminase, cinnamate 4-hydroxylase, coenzyme A ligase, peroxidase, and polyphenol oxidase), and up-regulated the expression of related genes, phenylalanine deaminase (PAL), trans-cinnamate monooxygenase (C4H), chalcone isomerase (CHI), and mangiferyl hydroxycinnamoyltransferase (HCT), while also promoting the accumulation of metabolites (total phenolics, flavonoids, and lignin) that have a restorative effect on drought stress. The continuous accumulation of H2O2 and the increase and then decrease in SPAD under waterlogging stress was also observed. Waterlogging stress also enhanced the activities of the above-mentioned metabolic enzymes, but the related genes were selectively down-regulated, e.g., C4H, 4CL, and peroxidase (POD), which resulted in the inhibition of the synthesis of lignin, flavonoids, and total phenols. These results indicate that the Capsicum annuum variety ‘Shuyu2’ is a drought-tolerant, waterlogging-sensitive variety. Meanwhile, the lignin and flavonoid pathway is a key pathway in response to drought stress in Capsicum annuum, which improves the theory of stress tolerance breeding in Capsicum annuum.
Nuclear mRNA export is highly regulated to ensure accurate cellular gene expression. Viral inhibition of cellular mRNA export can enhance viral access to the cellular translation machinery and ...prevent anti-viral protein production but is generally thought to be nonselective. We report that ORF10 of Kaposi’s sarcoma-associated herpesvirus (KSHV), a nuclear DNA virus, inhibits mRNA export in a transcript-selective manner to control cellular gene expression. Nuclear export inhibition by ORF10 requires an interaction with an RNA export factor, Rae1. Genome-wide analysis reveals a subset of cellular mRNAs whose nuclear export is blocked by ORF10 with the 3′ UTRs of ORF10-targeted transcripts conferring sensitivity to export inhibition. The ORF10-Rae1 interaction is important for the virus to express viral genes and produce infectious virions. These results suggest that a nuclear DNA virus can selectively interfere with RNA export to restrict host gene expression for optimal replication.
Display omitted
•ORF10 of KSHV inhibits nuclear export of mRNAs•Inhibition of ORF10 requires an interaction with an RNA export factor, Rae1•By interacting with Rae1, ORF10 selectively inhibits export of a subset of mRNAs•Interaction of ORF10 with Rae1 is required for efficient KSHV lytic gene expression
Viruses have evolved multiple mechanisms to inhibit cellular gene expression, thereby impeding host antiviral responses. Gong et al. identify a herpesvirus protein, ORF10, of KSHV that blocks nuclear export of selective mRNAs by interacting with an RNA export factor, Rae1. This interaction of ORF10 is critical for optimal KSHV replication.
PDF
