Reduction-Induced Decomposition: Spontaneous Formation of Monolithic Nanoporous Metals of Tunable Structural Hierarchy and Porosity

The beauty of dealloying, i.e., the selective dissolution of an alloy, lies in the spontaneous formation of bicontinuous nanoporous metal, whose robustness, conductivity, and high specific area are otherwise difficult to achieve in a monolithic form. However, a uniform structure of nanoporous metal requires a homogeneous alloy precursor, whose laborious fabrication has been limiting the application of dealloying and dealloyed materials. Here, we replace the alloy precursor with a compound, and design another type of selective dissolution, reduction-induced decomposition (RID). Using the RID of AgCl as an example, we chemically reduced bulk AgCl samples to create bicontinuous nanoporous Ag that resembles dealloyed structures. The monolithic material possesses a uniform ligament width of 72 nm and a specific area of 7.57 m²/g. The ligament width can be tuned in a range from 30 nm to 1 μm through coarsening, and the porosity from 57% to 87% by replacing silver cations in the compound with sodium cations. The RID of this multication compound can lead to a hierarchical structure, which evolves because of two simultaneous percolation dissolutions. The hierarchical nanoporous Ag delivered a stable performance as a high-capacity Ag/Ag_<i>x</i>O electrode owing to its micron-sized pores for fast mass transfer. RID not only provides an inexpensive alternative to dealloying, it also expands the design space of nanoporous materials for meeting diverse needs in electrochemical applications

Influenza Viral Hemagglutinin Peptide Inhibits Influenza Viral Entry by Shielding the Host Receptor

Influenza viral infection of the host begins by the attachment of viral hemagglutinin to a cell surface receptor. In the current study, a hemagglutinin fragment peptide library was screened using an H5N1 recombinant pseudotyped viral system. One peptide, designated HA-pep25, showed effective antiviral activity against both human and avian influenza viral strains (IC₅₀ = 12.0–51.0 μM). A mechanistic study demonstrated direct binding between HA-pep25 and sialyllactose, which mimics the host receptor for the influenza virus. This binding was independent of the presence of sialic acid on the cell membrane. By generating alanine substitutions in HA-pep25, eight residues were identified as essential for the peptide’s anti-influenza activity. HA-pep25 derived from hemagglutinin blocked influenza viral entry by shielding the host receptor on the cell membrane. This peptide might be a candidate drug for influenza virus entry inhibition and may be combined with other antivirals targeting different steps of the influenza viral life cycle

Crafting Insulating Polymer Mediated and Atomically Precise Metal Nanoclusters Photosensitized Photosystems Towards Solar Water Oxidization

Atomically precise metal nanoclusters (NCs) have been deemed as a new generation of metal nanomaterials because of their characteristic atomic stacking fashion, quantum confinement effect, and multitude of active sites. The discrete molecular-like energy band structure of metal NCs endows them with photosensitization capability for light harvesting and conversion. However, applications of metal NCs in photoelectrocatalysis are limited by the ultrafast charge recombination and unfavorable stability, impeding the construction of metal NC-based photosystems. In this work, we elaborately crafted multilayered metal oxide (MO)/(metal NCs/insulating polymer)n photoanodes by a facile layer-by-layer (LbL) assembly technique. In these well-defined heterostructured photoanodes, glutathione (GSH)-wrapped metal NCs (Agx@GSH, Ag9@GSH6, Ag16@GSH9, and Ag31@GSH19) and an insulating poly(allylamine hydrochloride) (PAH) layer are alternately deposited on the MO substrate in a highly ordered integration mode. We found that photoelectrons of metal NCs can be tunneled into the MO substrate via the intermediate ultrathin insulating polymer layer by stimulating the tandem charge transfer route, thus facilitating charge separation and boosting photoelectrochemical water oxidation performances. Our work would open a new frontier for judiciously regulating directional charge transport over atomically precise metal NCs for solar-to-hydrogen conversion

Table_1_Translation and validation of the Chinese version of the Self-awareness Scale for Nurses.DOCX

BackgroundLevels of self-awareness may affect the decision-making ability of clinical nurses and may also be related to mental health. Therefore, it is crucial to develop tools to identify nurses’ level of self-awareness. The purpose of this study was to investigate the reliability and validity of a short scale among Chinese nurses and to explore the factors associated with nurses’ self-awareness.MethodsA total of 957 participants were recruited, 549 participants were used for reliability tests and 408 subjects were used for impact factor studies. They completed the General Information Questionnaire, the Self-Awareness Scale for Nurses, and the Psychological Distress Scale. Exploratory factor analysis, confirmatory factor analysis, Cronbach’s alpha, and retest reliability were used to investigate the psychometric properties of the Self-Awareness Scale for Nurses. Multiple regression analyses were used in this study to investigate the relationship between nurses’ self-awareness and the independent variables.ResultsA 4-factor model of the Chinese version of the Self-Awareness Scale for Nurses was validated. The overall Cronbach’s alpha value for the Chinese version of the Self-Awareness Scale for Nurses was 0.873. Cronbach’s alpha values for each subscale ranged from 0.808 to 0.979. Significant predictors of each dimension of the Self-awareness and the total score of the scale were age and work experience.ConclusionThe Chinese version of the Self-Awareness Scale for Nurses is a valid and reliable scale.</p

Proposed mechanisms of the GSPs-induced apoptosis of cervical cancer cells.

<p>GSPs decrease the expression of Bcl-2 while increasing the expression of Bak-1 and result in the enhancement of mitochondrial membrane permeability associated with the loss of mitochondrial membrane potential (MMP). Subsequently, the release of cytochrome c from mitochondria leads to the activation of caspase-9 and -3, finally resulting in apoptosis.</p

GSPs induced the apoptosis of cervical cancer cells in vitro.

<p>HeLa and SiHa cells were treated with varying doses of GSPs for 48 h and then harvested for analysis of apoptosis. (A) The morphological changes of nuclei were examined by fluorescence microscopy using DAPI staining. The arrow indicates nuclear condensation and an apoptotic body (magnification, 40×). Flow cytometry analysis of Annexin V-FITC/PI double-stained HeLa (B) and SiHa (C) cells. The low right (LR) quadrant of the histograms indicates the early apoptotic cells, and the upper right (UR) quadrant indicates the late apoptotic cells. The treatment of HeLa (B) and SiHa (C) cells with GSPs results in significant increases in the percentages of apoptotic cells (including early stage and late stage). Values are expressed as the mean ± SD of three experiments in duplicate, *<i>p</i><0.05 <i>vs.</i> control; **<i>p</i><0.01 <i>vs.</i> control.</p

The effect of GSPs on the expression of Bcl-2 and Bak-1 in cervical cancer cells.

<p>The cells were treated with varying doses of GSPs for 48 h and then harvested. Cell lysates were prepared and subjected to western blot analysis. (A) Treatment of HeLa cells with GSPs resulted in a dose-dependent reduction of Bcl-2 expression and an increase in Bak-1 expression. (B) The relative expression of Bcl-2 and Bak-1 proteins in HeLa cells were calculated based on β-actin expression, which was used as loading control. (C) GSPs significantly decreased the expression of Bcl-2 and increased the expression of Bak-1 in SiHa cells. (D) The relative of expression levels of Bcl-2 and Bak-1 in SiHa cells are summarized. Representative blots are shown from three independent experiments, and values are expressed as the mean ± SD. *<i>p</i><0.05 <i>vs.</i> control; **<i>p</i><0.01 <i>vs.</i> control.</p

The apoptosis of cervical cancer cells induced by GSPs was mediated by the mitochondrial pathway.

<p>HeLa (A) and SiHa (C) cells were treated with the indicated doses of GSPs for 48 h and then harvested, stained with JC-1 dye, and finally analyzed by flow cytometry. GSPs resulted in a significant loss of mitochondrial membrane potential in HeLa (B) and SiHa cells (D). Caspase-3 activity in HeLa and SiHa cells was measured using a colorimetric protein assay, and treatment of HeLa (E) and SiHa (F) cells with GSPs resulted in a dose-dependent increase in the activity of caspase-3. GFP: Green fluorescence positive. Data are presented as the mean ± SD from three independent experiments, *<i>p</i><0.05 <i>vs.</i> control; **<i>p</i><0.01 <i>vs.</i> control.</p

GSPs inhibited the growth of cervical cancer xenografts in vivo.

<p>Mice were <i>s.c.</i> inoculated in the right flank with 2×10⁶ tumor cells. (A and B) Average tumor volumes in each group were measured on a regular basis. At the termination of the experiment, the tumor mass was harvested (C and D), and the wet weight of the tumor was recorded (E and F). (G and H) The histopathological examination of tumor xenografts was performed under light microscope, (magnification, 40×). Values are expressed as the mean ± SD, and the statistical significance of differences was analyzed by one-way ANOVA followed by the Tukey test. *<i>p</i><0.05 <i>vs.</i> control; **<i>p</i><0.01 <i>vs.</i> control.</p