Crystal Structure Regulation of CoSe2 Induced by Fe Dopant for Promoted Surface Reconstitution toward Energetic Oxygen Evolution Reaction.

Most nonoxide catalysts based on transition metal elements will inevitably change their primitive phases under anodic oxidation conditions in alkaline media. Establishing a relationship between the bulk phase and surface evolution is imperative to reveal the intrinsic catalytic active sites. In this work, it is demonstrated that the introduction of Fe facilitates the phase transition of orthorhombic CoSe2 into its cubic counterpart and then accelerates the Co-Fe hydroxide layer generation on the surface during electrocatalytic oxygen evolution reaction (OER). As a result, the Fe-doped cubic CoSe2 catalyst exhibits a significantly enhanced activity with a considerable overpotential decrease of 79.9 and 66.9 mV to deliver 10 mA·cm-2 accompanied by a Tafel slope of 48.0 mV·dec-1 toward OER when compared to orthorhombic CoSe2 and Fe-doped orthorhombic CoSe2, respectively. Density functional theory (DFT) calculations reveal that the introduction of Fe on the surface hydroxide layers will tune electron density around Co atoms and raise the d-band center. These findings will provide deep insights into the surface reconstitution of the OER electrocatalysts based on transition metal elements.

Pulse potential mediated selectivity for the electrocatalytic oxidation of glycerol to glyceric acid.

Preventing the deactivation of noble metal-based catalysts due to self-oxidation and poisonous adsorption is a significant challenge in organic electro-oxidation. In this study, we employ a pulsed potential electrolysis strategy for the selective electrocatalytic oxidation of glycerol to glyceric acid over a Pt-based catalyst. In situ Fourier-transform infrared spectroscopy, quasi-in situ X-ray photoelectron spectroscopy, and finite element simulations reveal that the pulsed potential could tailor the catalyst's oxidation and surface micro-environment. This prevents the overaccumulation of poisoning intermediate species and frees up active sites for the re-adsorption of OH adsorbate and glycerol. The pulsed potential electrolysis strategy results in a higher glyceric acid selectivity (81.8%) than constant-potential electrocatalysis with 0.7 VRHE (37.8%). This work offers an efficient strategy to mitigate the deactivation of noble metal-based electrocatalysts.

Research on the death psychology among Chinese during and after the COVID-19 pandemic.

Under the threat of the novel coronavirus, people are compelled to contemplate some ultimate existential questions, such as life and death. This study collected texts related to the death psychology from Sina Weibo, and after data cleaning, a total of 3868 Weibo texts were included. Study 1 employed grounded theory from qualitative research to explore the core categories and evolutionary mechanisms of people's psychology when facing death threats in the context of the pandemic. Study 2 utilized big data mining techniques such as topic mining and semantic network analysis to validate the effectiveness of the death psychology theory developed in qualitative research. The findings demonstrate that within the "Emotion-Cognition-Behavior-Value" framework, the implications of death threats manifest in four aspects: death anxiety, death cognition, coping efficacy, and sense of meaning. As time progresses, the study of death psychology can be segmented into four distinct phases: the tranquil phase prior to lifting pandemic restrictions, the threat phase at lifting pandemic restrictions onset, the coping phase mid-lifting pandemic restrictions, and the reformative phase post-lifting pandemic restrictions. The calculated outcomes of topic mining and semantic network analysis corroborate the coding results and theories derived from the grounded theory. This reaffirms that data mining technology can be a potent tool for validating grounded theory.

Treatment of immune thrombocytopenia with hetrombopag olamine tablets in a Kabuki syndrome patient with new KMT2D mutations.

Kabuki syndrome (KS) is a rare multisystem-affecting genetic disorder, and usually accompanied with autoimmune disorders such as immune thrombocytopenic purpura (ITP). Here, we report a 16-year-old patient with Kabuki syndrome with ITP and observe the therapeutic effect of TPO agonist hetrombopag olamine tablets. The duration of maintenance therapy and follow up were both 17 months. Whole exon sequencing (WES) of the patient's peripheral blood showed c.5775_5778del (p. Leu1926LysfsTer120) heterozygous mutation in the KMT2D gene, which was not reported before.

Dynamic Reconstitution Between Copper Single Atoms and Clusters for Electrocatalytic Urea Synthesis.

Electrocatalytic CN coupling between carbon dioxide and nitrate has emerged to meet the comprehensive demands of carbon footprint closing, valorization of waste, and sustainable manufacture of urea. However, the identification of catalytic active sites and the design of efficient electrocatalysts remain a challenge. Herein, the synthesis of urea catalyzed by copper single atoms decorated on a CeO2 support (denoted as Cu1 -CeO2 ) is reported. The catalyst exhibits an average urea yield rate of 52.84 mmol h-1 gcat. -1 at -1.6 V versus reversible hydrogen electrode. Operando X-ray absorption spectra demonstrate the reconstitution of copper single atoms (Cu1 ) to clusters (Cu4 ) during electrolysis. These electrochemically reconstituted Cu4 clusters are real active sites for electrocatalytic urea synthesis. Favorable CN coupling reactions and urea formation on Cu4 are validated using operando synchrotron-radiation Fourier transform infrared spectroscopy and theoretical calculations. Dynamic and reversible transformations of clusters to single-atom configurations occur when the applied potential is switched to an open-circuit potential, endowing the catalyst with superior structural and electrochemical stabilities.

XAF1 Protects Host against Emerging RNA Viruses by Stabilizing IRF1-Dependent Antiviral Immunity.

XIAP-associated factor 1 (XAF1) is an interferon (IFN)-stimulated gene (ISG) that enhances IFN-induced apoptosis. However, it is unexplored whether XAF1 is essential for the host fighting against invaded viruses. Here, we find that XAF1 is significantly upregulated in the host cells infected with emerging RNA viruses, including influenza, Zika virus (ZIKV), and SARS-CoV-2. IFN regulatory factor 1 (IRF1), a key transcription factor in immune cells, determines the induction of XAF1 during antiviral immunity. Ectopic expression of XAF1 protects host cells against various RNA viruses independent of apoptosis. Knockout of XAF1 attenuates host antiviral innate immunity in vitro and in vivo, which leads to more severe lung injuries and higher mortality in the influenza infection mouse model. XAF1 stabilizes IRF1 protein by antagonizing the CHIP-mediated degradation of IRF1, thus inducing more antiviral IRF1 target genes, including DDX58, DDX60, MX1, and OAS2. Our study has described a protective role of XAF1 in the host antiviral innate immunity against RNA viruses. We have also elucidated the molecular mechanism that IRF1 and XAF1 form a positive feedback loop to induce rapid and robust antiviral immunity. IMPORTANCE Rapid and robust induction of antiviral genes is essential for the host to clear the invaded viruses. In addition to the IRF3/7-IFN-I-STAT1 signaling axis, the XAF1-IRF1 positive feedback loop synergistically or independently drives the transcription of antiviral genes. Moreover, XAF1 is a sensitive and reliable gene that positively correlates with the viral infection, suggesting that XAF1 is a potential diagnostic marker for viral infectious diseases. In addition to the antitumor role, our study has shown that XAF1 is essential for antiviral immunity. XAF1 is not only a proapoptotic ISG, but it also stabilizes the master transcription factor IRF1 to induce antiviral genes. IRF1 directly binds to the IRF-Es of its target gene promoters and drives their transcriptions, which suggests a unique role of the XAF1-IRF1 loop in antiviral innate immunity, particularly in the host defect of IFN-I signaling such as invertebrates.

A Novel Sushi-IL15-PD1 CAR-NK92 Cell Line With Enhanced and PD-L1 Targeted Cytotoxicity Against Pancreatic Cancer Cells.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal malignancy with a limited response to current therapies. Novel and effective treatment is urgently needed. Herein, a chimeric antigen receptor (CAR)-NK92 cell line, with an interleukin (IL)-15Rα-sushi/IL-15 complex and a Programmed cell death-1(PD1) signal inverter was constructed and named SP ( S ushi-IL15- P D1). We showed that CAR expression enabled SP cells to proliferate independently of IL-2 and became more resistant to nutrition starvation-induced apoptosis. Meanwhile, SP cells were more effective than NK92 in PDAC cell killing assays in vitro and in vivo, and there was a positive correlation between the killing capability of SP cells and PD-L1 expression in pancreatic cancer cells. Based on the synergistic and comprehensive effects of the special CAR structure, the adhesion, responsiveness, degranulation efficiency, targeted delivery of cytotoxic granule content, and cytotoxicity of SP cells were significantly stronger than those of NK92. In conclusion, the SP cell line is a promising adoptive immunotherapy cell line and has potential value as an adjuvant treatment for pancreatic cancer, especially in patients with high PD-L1 expression.

Characterization, antioxidant, antineoplastic and immune activities of selenium modified Sagittaria sagittifolia L. polysaccharides.

This study proposed an optimal way to supplement organic selenium, boost polysaccharides solubility, antioxidant, anticancer, immune responses. A purified polysaccharide fraction of Sagittaria sagittifolia L. (PSSP) was successfully modified with selenium (Se-PSSP), and its characteristics, antioxidant, antineoplastic and immune activities were studied. The structure and the monosaccharide composition were determined by means of UV-visible spectrometry, FT-IR spectra, NMR spectra, X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM) and atomic force microscope (AFM). The results showed that both PSSP and Se-PSSP contained a pyranoid polysaccharide linked by α-glycosidic bonds in the main chain. In addition, PSSP and Se-PSSP were amorphous morphology without three-helix conformation. PSSP (47.12 kDa) was mainly composed of glucose, mannose and xylose with molar percentages of 55.82%, 14.86% and 14.35%, respectively. Se-PSSP (16.82 kDa) is mainly composed of glucose, xylose and galactose with molar percentages of 26.49%, 18.76% and 18.14%, respectively. Compared with PSSP, Se-PSSP showed stronger water-solubility, antioxidant activity, cytotoxicity and immunomodulatory activity than that of PSSP. These results suggested that Se-PSSP is a promising novel Se-supplement and may be served as an excellent potential antioxidant, antineoplastic, and immunomodulatory agents in the field of functional foods and medicine industry.

Polysaccharides as Potential Anti-tumor Biomacromolecules -A Review.

Cancer, as one of the most life-threatening diseases, has attracted the attention of researchers to develop drugs with minimal side effects. The bioactive macromolecules, such as the polysaccharides, are considered the potential candidates against cancer due to their anti-tumor activities and non-toxic characteristics. The present review provides an overview on polysaccharides' extraction, isolation, purification, mechanisms for their anti-tumor activities, structure-activity relationships, absorption and metabolism of polysaccharides, and the applications of polysaccharides in anti-tumor therapy. Numerous research showed extraction methods of polysaccharides had a significant influence on their activities. Additionally, the anti-tumor activities of the polysaccharides are closely related to their structure, while molecular modification and high bioavailability may enhance the anti-tumor activity. Moreover, most of the polysaccharides exerted an anti-tumor activity mainly through the cell cycle arrest, anti-angiogenesis, apoptosis, and immunomodulation mechanisms. Also, recommendations were made to utilize the polysaccharides against cancer.

Molecular-Scale Manipulation of Layer Sequence in Heteroassembled Nanosheet Films toward Oxygen Evolution Electrocatalysts.

Flocculation or restacking of different kinds of two-dimensional (2D) nanosheets into heterostructure nanocomposites is of interest for the development of high-performance electrode materials and catalysts. However, lacking a molecular-scale control on the layer sequence hinders enhancement of electrochemical activity. Herein, we conducted electrostatic layer-by-layer (LbL) assembly, employing oxide nanosheets (e.g., MnO2, RuO2.1, reduced graphene oxide (rGO)) and layered double hydroxide (LDH) nanosheets (e.g., NiFe-based LDH) to explore a series of mono- and bilayer films with various combinations of nanosheets and sequences toward oxygen evolution reaction (OER). The highest OER activity was attained in bilayer films of electrically conductive RuO2.1 nanosheets underlying catalytically active NiFe LDH nanosheets with mixed octahedral/tetrahedral coordination (NiFe LDHTd/Oh). At an overpotential of 300 mV, the RuO2.1/NiFe LDHTd/Oh film exhibited an electrochemical surface area (ECSA) normalized current density of 2.51 mA cm-2ECSA and a mass activity of 3610 A g-1, which was, respectively, 2 and 5 times higher than that of flocculated RuO2.1/NiFe LDHTd/Oh aggregates with a random appearance of a surface layer. First-principles density functional theory calculations and COMSOL Multiphysics simulations further revealed that the improved catalytic performance was ascribed to a substantial electronic coupling effect in the heterostructure, in which electrons are transferred from exposed NiFe LDHTd/Oh nanosheets to underneath RuO2.1. The study provides insight into the rational control and manipulation of redox-active surface layers and conductive underlying layers in heteroassembled nanosheet films at molecular-scale precision for efficient electrocatalysis.

Silicon nanosheets derived from silicate minerals: controllable synthesis and energy storage application.

Silicon plays a crucial part in developing high-performance energy storage materials, owing to a high specific capacity compared to carbon. Moreover, nanoscale silicon is beneficial for reducing the inherent disadvantage of large volume change during repeated lithiation/de-lithiation, while artificial synthesis methods usually involve complex procedures and high costs. On account of the abundant natural reserve and low cost, the manipulation of silicate minerals is a simple and economical approach to prepare silicon nanosheets. In this regard, this mini review introduces different classes of silicate minerals and summarizes some typical molten salt-assisted reduction methods and other valuable methods applied to prepare silicon nanosheets for energy storage. Finally, the challenges and perspectives in this field are also proposed.

Geographic modeling and simulation systems for geographic research in the new era: Some thoughts on their development and construction.

Regionality, comprehensiveness, and complexity are regarded as the basic characteristics of geography. The exploration of their core connotations is an essential way to achieve breakthroughs in geography in the new era. This paper focuses on the important method in geographic research: Geographic modeling and simulation. First, we clarify the research requirements of the said three characteristics of geography and its potential to address geo-problems in the new era. Then, the supporting capabilities of the existing geographic modeling and simulation systems for geographic research are summarized from three perspectives: Model resources, modeling processes, and operational architecture. Finally, we discern avenues for future research of geographic modeling and simulation systems for the study of regional, comprehensive and complex characteristics of geography. Based on these analyses, we propose implementation architecture of geographic modeling and simulation systems and discuss the module composition and functional realization, which could provide theoretical and technical support for geographic modeling and simulation systems to better serve the development of geography in the new era.

Purification, characterization, antioxidant and immunological activity of polysaccharide from Sagittaria sagittifolia L.

As a healthy food and traditional Chinese medicine, sagittaria sagittifolia L. has been used for a long history. Nevertheless, reports on the bioactivity and chemical characterization of S. sagittifolia L. polysaccharides are still very rare. In this paper, ultrasound-assisted method (UAE) was used to extract S. sagittifolia L. polysaccharides, after alcohol precipitation and column chromatography isolation, the structural characteristics, antioxidant and immunological activities of the purified polysaccharide (SPU60-W) were preliminarily investigated. The results indicated SPU60-W (16.62 kDa) was a pyranoid polysaccharide containing α-glycosidic bond composed of mannose, xylose, and glucose with a molar ratio of 2.69: 2.04: 95.27. It consisted of slender wormlike strands, which may involve some degree of aggregation of helices, as well as a small proportion of irregular spherical structures. Furthermore, antioxidant activity analysis showed that SPU60-W possess excellent hydroxyl and ABTS radical scavenging activity comparable to vitamin C (Vc), and moderate DPPH radical scavenging activity. Immunity tests suggested that SPU60-W significantly promoted the proliferation, phagocytosis and NO production of mouse macrophage RAW264.7. According to this study, SPU60-W might be utilized as a potent antioxidant and immunomodulator in food and medicinal industry.

Binding affinity, antioxidative capacity and in vitro digestion of complexes of grape seed procyanidins and pork, chicken and fish protein.

Studies have reported that procyanidins can interact with proteins, thereby affecting their structure, function, and bioaccessibility. In this paper, we investigated the interaction between grape seeds procyanidins (GSP) and animal source protein (from pig, chicken and fish), and the effects on the protein structure, antioxidant capacity and bioaccessibility of GSP. Fluorescence results showed that the binding constant of GSP-protein complex was 10-104 M-1, and the main forces were van der Waals force, hydrogen bonds and hydrophobic interactions. The antioxidant capacity of GSP was masked by GSP-protein complexes formed. The circular dichroism indicated that GSP had an effect on the content of α-helix and ß-sheet in the secondary structure of pork and chicken proteins, but had little effect on the secondary structure of fish protein. The results showed that the protein can bind to GSP and affect its antioxidant activity and bioaccessibility. This study can provide reference for further study on the digestion and absorption of the complexes and offer health guidance in the preparation of diets.

Optimization, characterization, rheological study and immune activities of polysaccharide from Sagittaria sagittifolia L.

To improve the extraction efficiency of polysaccharides from Sagittaria sagittifolia L. (SPU) by ultrasonic assisted extraction (UAE), the optimal extraction conditions were optimized as follows: extraction temperature of 85℃, extraction time of 15 min and ratio of liquid to raw material 43 mL/g, under these conditions, the yield of SPU increased by about 168 % compared with hot water extraction (HWE). After separation and purification by DEAE-52 cellulose column and Sephadex G-50 column, the pure polysaccharide fraction (SPU70-W1) was obtained, and its structure, rheology and immune activity were analyzed. The results indicated that SPU70-W1 (7.70 kDa) contained mannose, glucose and galactose in the molar ratio of 2.06:93.58:4.36 with typical pseudoplasticity fluids behavior and possessed the backbone of →2,6)-α-D-Glcp-(1→, →3,6)-α-D-Glcp-(1→, α-D-Glcp-(1→ and 6)-α-D-Glcp-(1→. In addition, SPU70-W1 exhibited remarkable immunomodulatory activity. Thus, SPU70-W1 could contribute to the food, medicine, cosmetics as a functional additive.

Structural characterization and physicochemical properties of arrowhead resistant starch prepared by different methods.

Resistant starch (RS) served as a novel functional ingredient has attracted much attention. In this paper, the structure and physicochemical properties of arrowhead resistant starch (ARS) prepared by subcritical water (SW-ARS), ultrasound-subcritical water (USW-ARS), autoclaving (AM-ARS) and ultrasound-autoclaving (UAM-ARS) were investigated. The results showed that the structure of starch granules was completely disrupted and the size of starch granules was obviously increased. SW-ARS, USW-ARS, AM-ARS and UAM-ARS exhibited a B-type crystallinity pattern with different degree of crystallinity. UAM-ARS displayed the highest molecular order with the highest degree of double helixes while SW-ARS, USW-ARS and AM-ARS showed a lower degree of molecular order than that of arrowhead native starch (ANS). The ANS and ARS prepared by four methods possessed high gelation enthalpy in which UAM-ARS had the highest gelation enthalpy, indicating that they had excellent thermostability. Therefore, ANS and the resulting ARS may be a promising starch-based material. All these results are expected to provide information on the preparation and application of ANS and ARS.

Preparation, characterization and bioactivity of polysaccharide fractions from Sagittaria sagittifolia L.

To ascertain the preliminary structural characteristics and biological activity of different fractions of polysaccharides from Sagittaria sagittifolia L. (SPCs) by ultrasonic assisted extraction (UAE), four new polysaccharides (SPC-60, SPC-70, SPC-80 and SPC-90) were successively fractionated by ethanol. The results implied that except for neutral sugar, four contained proteins and uronic acids in their structure, which were further confirmed by the ultraviolet and infrared spectra. Molecular weight and monosaccharide composition analysis exhibited that SPC-60 (52.0 kDa), SPC-70 (294.9 kDa), SPC-80 (230.6 kDa) and SPC-90 (229.4 kDa) were a neutral polysaccharide composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with dramatically different mole ratios. In addition, SPC-70 exhibited stronger antioxidant activity in vitro than the other three components. SPCs could significantly promote macrophage proliferation, NO release and phagocytosis. Thus, these results provided a reference for applications of S. sagittifolia L. polysaccharides which would benefit the development of industry and agriculture.

Effect of alkali concentration on digestibility and absorption characteristics of rice residue protein isolates and lysinoalanine.

The effect of alkali concentration on the digestibility and absorption characteristics of rice residue protein isolates (RPI) and lysinoalanine (LAL) was studied. When NaOH concentration was 0.03 M, the in vitro digestibility of RPI reached a maximum, and when NaOH concentration was higher than 0.03 M, the in vitro digestibility decreased. Alkali treatment reduced the release of all amino acids, especially arginine, lysine, phenylalanine, tyrosine, cysteine, and threonine. LAL only released 2.65-9.28% of the total LAL content, which was mainly combined with longer peptide chains, and the molecular weight was mostly accumulated between 1000 Da and 3000 Da. The experimental model of rats in the small intestine perfusion showed that the high alkali concentration significantly reduced the absorption rate of RPI, and LAL had no specific absorption site in the small intestine of rats, and was not available for intestinal absorption.

Vitexin ameliorates high fat diet-induced obesity in male C57BL/6J mice via the AMPKα-mediated pathway.

Vitexin, a bioactive compound isolated from hawthorn leaf extracts, has been reported to exhibit many biological activities, such as anticancer, antioxidation, and adipogenesis inhibition activities. The current study explored the effects of vitexin on high fat diet (HFD)-induced obesity/adipogenesis in male C57BL/6J mice and 3T3-L1 adipocytes, as well as the underlying mechanisms thereof. Vitexin significantly mitigated HFD-induced body weight gain and adiposity. Vitexin also partially normalized serum, hepatic lipid contents, and decreased adipocyte size induced by the HFD. Consistently, there were significant effects of vitexin on important regulators of lipid metabolism, including AMP-activated protein kinase-α (AMPKα), CAATT element binding protein-α (C/EBPα), and fatty acid synthase (FAS) in white adipose tissue. Moreover, vitexin significantly inhibited fat accumulation in 3T3-L1 adipocytes, and this was totally abolished by compound C (an AMPKα inhibitor). These results suggest that vitexin may prevent HFD-induced obesity/adipogenesis via the AMPKα mediated pathway.

Serpentine Ni3 Ge2 O5 (OH)4 Nanosheets with Tailored Layers and Size for Efficient Oxygen Evolution Reactions.

Layered serpentine Ni3 Ge2 O5 (OH)4 is compositionally active and structurally favorable for adsorption and diffusion of reactants in oxygen evolution reactions (OER). However, one of the major problems for these materials is limited active sites and low efficiency for OER. In this regard, a new catalyst consisting of layered serpentine Ni3 Ge2 O5 (OH)4 nanosheets is introduced via a controlled one-step synthetic process where the morphology, size, and layers are well tailored. The theoretical calculations indicate that decreased layers and increased exposure of (100) facets in serpentine Ni3 Ge2 O5 (OH)4 lead to much lower Gibbs free energy in adsorption of reactive intermediates. Experimentally, it is found that the reduction in number of layers with minimized particle size exhibits plenty of highly surface-active sites of (100) facets and demonstrates a much enhanced performance in OER than the corresponding multilayered nanosheets. Such a strategy of tailoring active sites of serpentine Ni3 Ge2 O5 (OH)4 nanosheets offers an effective method to design highly efficient electrocatalysts.