61 research outputs found

    Alchemical and structural distribution based representation for improved QML

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    We introduce a representation of any atom in any chemical environment for the generation of efficient quantum machine learning (QML) models of common electronic ground-state properties. The representation is based on scaled distribution functions explicitly accounting for elemental and structural degrees of freedom. Resulting QML models afford very favorable learning curves for properties of out-of-sample systems including organic molecules, non-covalently bonded protein side-chains, (H2_2O)40_{40}-clusters, as well as diverse crystals. The elemental components help to lower the learning curves, and, through interpolation across the periodic table, even enable "alchemical extrapolation" to covalent bonding between elements not part of training, as evinced for single, double, and triple bonds among main-group elements

    Polyaspartamide Derivative Nanoparticles with Tunable Surface Charge Achieve Highly Efficient Cellular Uptake and Low Cytotoxicity

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    Cationic nanocarrier mediated intracellular therapeutic agent delivery acts as a double-edged sword: the carriers promote cellular uptake, but interact nonspecifically and strongly with negatively charged endogenic proteins and cell membranes, which results in aggregates and high cytotoxicity. The present study was aimed at exploring zwitterionic polyaspartamide derivative nanoparticles for efficient intracellular delivery with low cytotoxicity. Poly­(aspartic acid) partially grafted tetraethylenepentamine (PASP-pg-TEPA) with different isoelectric points (IEPs) was synthesized. The PASP-pg-TEPA formed zwitterionic nanoparticles with an irregular core and a well-defined shell structure in aqueous medium. Their particle size decreased from about 300 to 80 nm with an increase of the IEP from 7.5 to 9.1. The surface charge of the PASP-pg-TEPA nanoparticles could be tuned from positive to negative with a change of the pH of the medium. The nanoparticles with an IEP above 8.5 exhibited good stability under simulated physiological conditions. It was noted that the zwitterionic PASP-pg-TEPA nanoparticles displayed highly efficient cellular uptake in HeLa cells (approximately 99%) in serum-containing medium and did not adversely affect the cell viability at concentrations up to 1 mg/mL. Furthermore, thermodynamic analysis using isothermal titration calorimetry provided direct evidence that these zwitterionic nanoparticles had low binding affinities for serum protein. Therefore, the zwitterionic PASP-pg-TEPA nanoparticles could overcome limitations of cationic nanocarriers and achieve efficient intracellular delivery with low cytotoxicity

    Self-Catalyzed Carbon Dioxide Adsorption by Metal–Organic Chains on Gold Surfaces

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    Efficient capture of CO<sub>2</sub> by chemical means requires a microscopic understanding of the interactions of the molecule–substrate bonding and adsorption-induced collective phenomena. By molecule-resolved imaging with scanning tunneling microscopy (STM), we investigate self-catalyzed CO<sub>2</sub> adsorption on one-dimensional (1D) substrates composed of self-assembled metal–organic chains (MOCs) supported on gold surfaces. CO<sub>2</sub> adsorption turns on attractive interchain interactions, which induce pronounced surface structural changes; the initially uniformly dispersed chains gather into close packed bundles, which are held together by highly ordered, single molecule wide CO<sub>2</sub> ranks. CO<sub>2</sub> molecules create more favorable adsorption sites for further CO<sub>2</sub> adsorption by mediating the interchain attraction, thereby self-catalyzing their capture. The release of CO<sub>2</sub> molecules by thermal desorption returns the MOCs to their original structure, indicating that the CO<sub>2</sub> capture and release are reversible processes. The real space microscopic characterization of the self-catalyzed CO<sub>2</sub> adsorption on 1D substrates could be exploited as platform for design of molecular materials for CO<sub>2</sub> capture and reduction

    ERK1/2 leads to adiponectin upregulating P4Hα1 expression in IL-6-stimulated HASMCs.

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    <p>(A) p-ERK level. (B) Sp1 DNA-binding activity. (C) Subcellular localization of Sp1. (D) mRNA expression of P4Hα1. (E) Protein expression of P4Hα1. *, <i>p</i><0.05 vs. con; #, <i>p</i><0.05 vs. IL-6.</p

    Image_2_Genome-Wide Characterization of Endogenous Retroviruses in Bombyx mori Reveals the Relatives and Activity of env Genes.TIF

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    <p>Endogenous retroviruses (ERVs) are retroviral sequences that remain fixed in the host genome, where they could play an important role. Some ERVs have been identified in insects and proven to have infectious properties. However, no information is available regarding Bombyx mori ERVs (BmERVs) to date. Here, we systematically identified 256 potential BmERVs in the silkworm genome via a whole-genome approach. BmERVs were relatively evenly distributed across each of the chromosomes and accounted for about 25% of the silkworm genome. All BmERVs were classified as young ERVs, with insertion times estimated to be less than 10 million years. Seven BmERVs possessing the env genes were identified. With the exception of the Orf133 Helicoverpa armigera nuclear polyhedrosis virus, the env sequences of BmERVs were distantly related to genes encoding F (Fa and Fb) and GP64 proteins from Group I and Group II NPVs. In addition, only the amino acid sequence of the BmERV-21 envelope protein shared a similar putative furin-like cleavage site and fusion peptide with Group II baculoviruses. All of the env genes in the seven BmERVs were verified to exist in the genome and be expressed in the midgut and fat bodies, which suggest that BmERVs might play an important role in the host biology.</p

    Image_1_Genome-Wide Characterization of Endogenous Retroviruses in Bombyx mori Reveals the Relatives and Activity of env Genes.TIF

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    <p>Endogenous retroviruses (ERVs) are retroviral sequences that remain fixed in the host genome, where they could play an important role. Some ERVs have been identified in insects and proven to have infectious properties. However, no information is available regarding Bombyx mori ERVs (BmERVs) to date. Here, we systematically identified 256 potential BmERVs in the silkworm genome via a whole-genome approach. BmERVs were relatively evenly distributed across each of the chromosomes and accounted for about 25% of the silkworm genome. All BmERVs were classified as young ERVs, with insertion times estimated to be less than 10 million years. Seven BmERVs possessing the env genes were identified. With the exception of the Orf133 Helicoverpa armigera nuclear polyhedrosis virus, the env sequences of BmERVs were distantly related to genes encoding F (Fa and Fb) and GP64 proteins from Group I and Group II NPVs. In addition, only the amino acid sequence of the BmERV-21 envelope protein shared a similar putative furin-like cleavage site and fusion peptide with Group II baculoviruses. All of the env genes in the seven BmERVs were verified to exist in the genome and be expressed in the midgut and fat bodies, which suggest that BmERVs might play an important role in the host biology.</p

    Effect of dose and time of IL-6 treatment on P4Hα1 expression.

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    <p>(A and C) mRNA expression of P4Hα1. (B and D) Protein expression of P4Hα1. Data are representative of 3 independent experiments (means±SD). *, <i>p</i><0.05 vs. con.</p

    Additional file 2: Figure S2. of GABPA predicts prognosis and inhibits metastasis of hepatocellular carcinoma

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    a and b Knockdown of GABPA in SMMC-7721 promoted cell invasion and migration. c and d Ectopic expression of GABPA in SK-Hep1 inhibited invasion and migration of HCC cells. (*P < 0.05, **P < 0.01). (TIFF 25518 kb

    Effect of adiponectin overexpression on collagen production.

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    <p>Content of (A) procollagen I, (B) procollagen III, (C) collagen I, (D) collagen III. Data are representative of 3 independent experiments (means±SD). *, <i>p</i><0.05 vs. con; #, <i>p</i><0.05 vs. IL-6.</p
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