Direct Z-Scheme SnSe2/SnSe Heterostructure Passivated by Al2O3 for Highly Stable and Sensitive Photoelectrochemical Photodetectors.

To mimic the natural photosynthesis system, a Z-scheme heterostructure is proposed as a viable and effective strategy for efficient solar energy utilization such as photocatalysis and photoelectrochemical (PEC) water splitting due to the high carrier separation efficiency, fast charge transport, strong redox, and wide light absorption. However, it remains a huge challenge to form a direct Z-scheme heterostructure due to the internal electric-field restriction and vital band-alignment at the interface. Herein, the van der Waals heterostructure based on the allotrope SnSe2 and SnSe is designed and synthesized by a two-step vapor phase deposition method to overcome the limitation in the formation of the Z-scheme heterostructure for the first time. The Z-scheme heterostructure of SnSe2/SnSe is confirmed by X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, PEC measurement, density functional theory calculations, and water splitting. Strikingly, the PEC photodetectors based on the Z-scheme heterostructure show a synergistic effect of superior stability from SnSe and fast photoresponse from SnSe2. As such, the SnSe2/SnSe Z-scheme heterostructure shows a good photodetection performance in the ultraviolet to visible wavelength range. Furthermore, the photodetector shows a faster response/recovery time of 13/14 ms, a higher photosensitivity of 529.13 µA/W, and a higher detectivity of 4.94 × 109 Jones at 475 nm compared with those of single components. Furthermore, the photodetection stability of the SnSe2/SnSe is also greatly improved by a-thin-Al2O3-layer passivation. The results imply the promising rational design of a direct Z-scheme heterostructure with efficient charge transfer for high performance of optoelectronic devices.

Pharmacodynamics of human interferon α1b against severe acute respiratory syndrome coronavirus 2 Omicron strain in vitro / 中国生物制品学杂志

@#Objective To evaluate the pharmacodynamics of human interferon(IFN)α1b against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron strain in vitro.Methods Total four drugs human IFNα1b bulk,human IFNα1b eye drops,human IFNα1b spray and Remdesivir were detected for cytotoxicity by CCK-8 assay.The inhibitory effect of human IFNα1b on SARS-CoV-2 Omicron strains(BA.5/BA.2/BA.1)was determined by qPCR.Results Human IFNα1b bulk of the maximum concentration(1 × 107IU/mL)and Remdesivir of the maximum concentration(150 μmol/L)did not achieve half cytotoxicity to Vero cells;The median cytotoxicity concentrations(CC_(50))of human IFNα1b eye drops and human IFNα1b sprays were 29 958 and 37 550 IU/mL,respectively,showing toxicity to Vero cells.The median effective concentrations(EC_(50))of human IFNα1b against virus strains BA.1,BA.2 and BA.5 after incubation for 2 h in advance were 9.30,13.38 and 12.33 IU/mL and those of Remdesivir were 0.314 7,0.291 0 and0.300 3 μmol/L.When incubation with virus simultaneously,the EC_(50)of human IFNα1b to BA.1,BA.2 and BA.5 were19.68,10.91 and 18.84 IU/mL and those of the control drug Remdesivir were 0.320 5,0.274 4 and 0.304 1 μmol/L,respectively.Conclusion At the cell level in vitro,human IFNα1b of very low activity showed a good inhibitory effect on SARS-CoV-2 Omicron strain,which was expected to be a clinical specific drug for the treatment of SARS-CoV-2 Omicron strain infection.

The in vitro estrogenic activity of the crude drugs found in Japanese herbal medicines prescribed for menopausal syndrome was enhanced by combining them.

BACKGROUND: Japanese herbal medicines can be used as alternatives to estrogen therapy and are sometimes prescribed for menopausal syndrome because they have fewer side effects and are associated with better compliance than estrogen therapy, but little is known about the pharmacological mechanisms of such treatments. This study aimed to explore the mechanisms responsible for the estrogen-like effects of five widely prescribed Japanese herbal medicines (unkeito, kamishoyosan, nyoshinsan, keishibukuryogan, and tokishakuyakusan). METHODS: We evaluated the estrogenic activity of these five Japanese herbal medicines and their metabolites using an estrogen receptor (ER)-dependent cell proliferation bioassay and an ER-dependent reporter assay. We also investigated the estrogenic activity of the crude drugs within the medicines and attempted to detect inter-crude drug synergistic effects using the ER-dependent reporter assay. RESULTS: We found that unkeito, kamishoyosan, and nyoshinsan exhibited estrogenic activity, and they displayed stronger estrogenic activity after being metabolized. Then, we focused on investigating the estrogenic activity of the crude drugs present within unkeito. We found that glycyrrhizae radix, cinnamomi cortex, evodiae fructus, and zingiberis rhizoma demonstrated ERß-dependent estrogenic activity. The combined use of evodiae fructus and glycyrrhizae radix, or evodiae fructus and cinnamomi cortex produced synergistic ERß-dependent estrogenic activity. CONCLUSION: It was suggested that unkeito, kamishoyosan, and nyoshinsan exert estrogenic activity, and hence, might be useful for treating menopausal syndrome. Furthermore, synergistic estrogenic effects were detected between some of the crude drugs present within unkeito.

Cells Expressing Prominin-1 in Neonatal Murine Inferior Colliculus Differentiate into Neurons and Glia.

Inferior colliculus (IC) is a major center for the integration and processing of acoustic information from ascending auditory pathways. Damage to the IC as well as normal aging can impair auditory function. Novel strategies such as stem cell (SC)-based regenerative therapy are required for functional recovery because mature neural cells have a minimal regenerative capacity after an injury. However, it is not known if there are neural stem cells (NSCs) in the IC. Herein, we screened for NSCs by surface marker analysis using flow cytometry. Isolated IC cells expressing prominin-1 (CD133) exhibited the cardinal NSC properties self-renewal capacity, expression of known NSC markers (SOX2 and nestin), and multipotency. Prominin-1-expressing cells from neonatal IC generated neurospheres, and culture of these neurospheres in differentiation-conditioned medium gave rise to gamma-aminobutyric acid-ergic (GABAergic) neurons, astrocytes, and oligodendrocytes. The presence of NSC-like cells in the IC has important implications for understanding IC development and for potential regenerative therapy.

Synergistic interaction of PMAP-36 and PRW4 with aminoglycoside antibiotics and their antibacterial mechanism.

The antimicrobial peptide PMAP-36 is a highly cationic and amphipathic α-helical peptide. PRW4 is a truncated analog that replaces paired lysine residues with tryptophan along the N-terminal and deletes the C-terminal hydrophobic tail of PMAP-36. Studies on the two peptides have already been performed. However, whether there is a synergistic effect with antibiotics has not been investigated, and the study of the antibacterial mechanism of the peptides is inadequate. In this study, antibiotic-peptide combinations were tested against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, and the confocal laser scanning microscopy (LSCM) and DNA gel retardation were measured. The results indicated synergy between the peptides and gentamicin when tested against E. coli [fractional lethal concentration (FLC) < 0.5]; partial synergy was observed between the peptides and gentamicin against S. aureus (0.5 < FLC < 1); and streptomycin showed no reaction with the peptides against E. coli and S. aureus (1 < FLC < 4). LSCM and DNA binding suggest that PMAP-36 was able to translocate across the bacterial membranes and interact with intracellular DNA, but PRW4 presented no DNA-binding ability. These results indicate that the combination of PMAP-36 and PRW4 with aminoglycosides may provide useful information for clinical application, and the antibacterial mechanism of peptides likely does not solely involve cytoplasmic-membrane permeabilization.

Antimicrobial properties and membrane-active mechanism of a potential α-helical antimicrobial derived from cathelicidin PMAP-36.

Antimicrobial peptides (AMPs), which present in the non-specific immune system of organism, are amongst the most promising candidates for the development of novel antimicrobials. The modification of naturally occurring AMPs based on their residue composition and distribution is a simple and effective strategy for optimization of known AMPs. In this study, a series of truncated and residue-substituted derivatives of antimicrobial peptide PMAP-36 were designed and synthesized. The 24-residue truncated peptide, GI24, displayed antimicrobial activity comparable to the mother peptide PMAP-36 with MICs ranging from 1 to 4 µM, which is lower than the MICs of bee venom melittin. Although GI24 displayed high antimicrobial activity, its hemolytic activity was much lower than melittin, suggesting that GI24 have optimal cell selectivity. In addition, the crucial site of GI24 was identified through single site-mutation. An amino acid with high hydrophobicity at position 23 played an important role in guaranteeing the high antimicrobial activity of GI24. Then, lipid vesicles and whole bacteria were employed to investigate the membrane-active mechanisms. Membrane-simulating experiments showed that GI24 interacted strongly with negatively charged phospholipids and weakly with zwitterionic phospholipids, which corresponded well with the data of its biological activities. Membrane permeabilization and flow cytometry provide the evidence that GI24 killed microbial cells by permeabilizing the cell membrane and damaging membrane integrity. GI24 resulted in greater cell morphological changes and visible pores on cell membrane as determined using scanning electron microscopy (SEM) and transmission electron microscope (TEM). Taken together, the peptide GI24 may provide a promising antimicrobial agent for therapeutic applications against the frequently-encountered bacteria.

Design of imperfectly amphipathic α-helical antimicrobial peptides with enhanced cell selectivity.

Antimicrobial peptides (AMPs), which are produced by multicellular organisms as a defense mechanism against competing pathogenic microbes, appear to be excellent candidates for the development of novel antimicrobial agents. Amphipathicity is traditionally believed to be crucial to the de novo design or systematic optimization of AMPs. In this study, we designed a series of short α-helical AMPs with imperfect amphipathicity to augment the arsenal of strategies and to gain further insights into their antimicrobial and hemolytic activity. These imperfectly amphipathic α-helical AMPs were designed by replacing the paired charged amino acid residues on the polar face of an amphipathic peptide with tryptophan residues on the basis of α-helical protein folding principles. PRW4, an imperfectly amphipathic α-helical AMP with hydrogen bonds formed by paired tryptophan residues, was observed to be more selective towards bacterial cells than toward human red blood cells. PRW4 was also effective against Gram-negative and Gram-positive bacteria, and fluorescence spectroscopy, flow cytometry, scanning electron microscopy and transmission electron microscopy indicated that PRW4 killed microbial cells by permeabilizing the cell membrane and damaging their membrane integrity. Therefore, disruptive amphipathicity has excellent potential for the rational design and optimization of AMPs with promising antimicrobial activities.

Fabrication of copper sulfide hierarchical architectures with tunable morphologies and sizes by microwave-biomolecular assistance method.

A facile microwave-biomolecular assistance method has been used to synthesize copper sulfide nanomaterials. In this process, the histidine as the directing and assembling agent plays an important role in the formation of the different hierarchical architectures. The morphologies and the sizes of the products can be tuned by adjusting the molar ratio of Cu2+/histidine and Cu2+/thiourea. The effect of other experiment parameters such as the reaction temperature, the power of microwave irradiation, and reaction time on the morphology and the size has been also discussed in detail. The possible reaction and growth mechanisms of the formation different hierarchical architectures are also discussed. In addition, the optical properties of these copper sulfides nanomaterials were investigated and the photocatalytic activity of different hierarchical architectures has been tested by the degradation of methyl orange (MO) under UV-light irradiation.

Molecular cloning and stress-dependent regulation of potassium channel gene in Chinese cabbage (Brassica rapa ssp. Pekinensis).

Potassium channels are important for many physiological functions in plants, one of which is to regulate plant adaption to stress conditions. In this study, KCT2, the gene encoding a membrane-bound protein potassium channel (GenBank accession number: ), was isolated from Chinese cabbage (Brassica rapa ssp. Pekinensis) by RACE-PCR technique. Bioinformatics methods were performed for the gene structure and molecular similarity analysis. The KCT2 expression patterns under various stress conditions were studied by semi-quantitative RT-PCR. DNA gel blot was used to analyze genomic organization. The putative KCT2 was found to contain five membrane-spanning segments, a pore-forming domain (P-domain) between the last two transmembrane spans, a TxxTxGYGD motif in the P-domain and a putative cyclic nucleotide-binding-like domain within a long C-terminal region. KCT2 is closest to KAT2 in Arabidopsis. KCT2 could be a one-copy gene with different isoforms or belong to a small gene family with four or five members. KCT2 was expressed more strongly in leaves than in shoots and roots. KCT2 transcription products were up-regulated by a 4-h-incubation in abscisic acid (ABA) and various stress treatment including cold stress (4 degrees C) for 24 h, drought stress for 1h, and salt stress for 12 h. KCT2 transcription was not affected by anoxia stress for 8h and was down-regulated with cold stress for 48 h. KCT2 was cloned for the first time from the genus Brassica. Expression analysis indicated that in the early stage of plant adaption to stress conditions KCT2 is up-regulated, which results in a stimulation of potassium transport.