130 research outputs found

    PGMA-Based Cationic Nanoparticles with Polyhydric Iodine Units for Advanced Gene Vectors

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    It is crucial for successful gene delivery to develop safe, effective, and multifunctional polycations. Iodine-based small molecules are widely used as contrast agents for CT imaging. Herein, a series of star-like poly­(glycidyl methacrylate) (PGMA)-based cationic vectors (II-PGEA/II) with abundant flanking polyhydric iodine units are prepared for multifunctional gene delivery systems. The proposed II-PGEA/II star vector is composed of one iohexol intermediate (II) core and five ethanolamine (EA) and II-difunctionalized PGMA arms. The amphipathic II-PGEA/II vectors readily self-assemble into well-defined cationic nanoparticles, where massive hydroxyl groups can establish a hydration shell to stabilize the nanoparticles. The II introduction improves cell viabilities of polycations. Moreover, by controlling the suitable amount of introduced II units, the resultant II-PGEA/II nanoparticles can produce fairly good transfection performances in different cell lines. Particularly, the II-PGEA/II nanoparticles induce much better in vitro CT imaging abilities in tumor cells than iohexol (one commonly used commercial CT contrast agent). The present design of amphipathic PGMA-based nanoparticles with CT contrast agents would provide useful information for the development of new multifunctional gene delivery systems

    Biodegradation of Phenol from Wastewater by Microorganism Immobilized in Bentonite and Carboxymethyl Cellulose Gel

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    <p>This study presents a microbial process for phenol degradation in coking wastewater. The optimum immobilized condition of the strain for degrading phenol was determined through orthogonal experiment. The free and immobilized microorganisms were examined for their capabilities on degrading phenol. Results indicated that the optimum immobilized conditions were 20% microorganism suspension, 5% bentonite, 3% sodium carboxymethyl cellulose content, and 1 h of crosslinking time. The biodegradation rate was optimized at 35°C and 0.23 gmL<sup>−1</sup> of immobilized microorganism bead. The degrading rate for the immobilized microorganism bead was up to 95.96% at an initial phenol concentration of 100 mgL<sup>−1</sup>; however, the immobilized microorganism considerably took more time (288 h) to reach 94.6% removal efficiency at a much higher concentration of 1000 mgL<sup>−1</sup>. The batch experiment demonstrated that 94.50% of phenol was removed using the beads with the immobilized microorganism at an initial concentration of 500 mgL<sup>−1</sup>. By contrast, only 24.60% and 33.88% of phenol were degraded using the gel beads without and with free microorganisms, respectively. The immobilized microorganism beads can used reused for up to nine cycles at the same initial phenol concentration (50 mgL<sup>−1</sup>) and can be stored up to 40 d without loss of its degradation capacity.</p

    Catalytic Asymmetric Synthesis of Tröger’s Base Analogues with Nitrogen Stereocenter

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    Nitrogen stereocenters are common chiral units in natural products, pharmaceuticals, and chiral catalysts. However, their research has lagged largely behind, compared with carbon stereocenters and other heteroatom stereocenters. Herein, we report an efficient method for the catalytic asymmetric synthesis of Tröger’s base analogues with nitrogen stereocenters via palladium catalysis and home-developed GF-Phos. It allows rapid construction of a new rigid cleft-like structure with both a C- and a N-stereogenic center in high efficiency and selectivity. A variety of applications as a chiral organocatalyst and metallic catalyst precursors were demonstrated. Furthermore, DFT calculations suggest that the NH···O hydrogen bonding and weak interaction between the substrate and ligand are crucial for the excellent enantioselectivity control

    Additional file 5 of Establishment and validation of an immune infiltration predictive model for ovarian cancer

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    Additional file 5: Table S1. Clinical information of TCGA-OV patients. Table S2. Immune-related genesets enriched in TP53 MUT OVs. Table S3. Differentially expressed immune-related genes between TP53 WT and TP53 MUT OVs.Table S4. Univariate Cox regression analysis of differentially expressed immune-related genes. Table S5. Analysis of correlations between risk score and immune checkpoints. Table S6. Top 20 clusters with their representative enriched terms by Metascape

    Carbon Dot Nanomaterials with High Interfacial Activity for Unconventional Reservoir Development

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    Carbon dot nanomaterials (<10 nm) exhibit superior application prospects as oil displacement materials for unconventional reservoir development. However, the limited oil–water and oil–solid interfacial activity of carbon dot nanomaterials restricts their broader application. In this study, carbon dot nanomaterials (CDs) are expeditiously prepared via a microwave-assisted synthesis method utilizing urea and citric acid as precursor compounds. OAB-modified active carbon dot nanomaterials (OCDs) are prepared by grafting oleic acid amidopropyl betaine (OAB) through hydrothermal reaction at 90 °C for 5 h using CDs as a carbon dot carrier. Stability experiments show that the plentiful hydrophilic groups present on the surface of the OCD augment electrostatic repulsion among them, thereby imparting dispersibility, temperature tolerance (90 °C), and salt resistance (2.6 × 104 mg/L). Additionally, OCDs demonstrate optimal effectiveness at a concentration of 0.5 wt %. At this concentration, OCDs can reduce the interfacial tension to 0.66 mN/m and achieve the underwater oil contact angle to 126°. Within 24 h, OCDs can strip 60.6% of the oil film. OCDs show the excellent ability to enhance oil–water and oil–solid interfacial activity. Meanwhile, OCD nanofluids can effectively form emulsions with crude oil and spontaneously demulsify within 2 h in a state. Core flooding tests demonstrate that OCD nanofluids, when compared with simulated formation water, reduce injection pressure by 46.3% and enhance oil recovery by 31.1%. This study offers a promising solution for the efficient development of unconventional reservoirs with carbon dot nanomaterials

    Catalytic Asymmetric Synthesis of Tröger’s Base Analogues with Nitrogen Stereocenter

    No full text
    Nitrogen stereocenters are common chiral units in natural products, pharmaceuticals, and chiral catalysts. However, their research has lagged largely behind, compared with carbon stereocenters and other heteroatom stereocenters. Herein, we report an efficient method for the catalytic asymmetric synthesis of Tröger’s base analogues with nitrogen stereocenters via palladium catalysis and home-developed GF-Phos. It allows rapid construction of a new rigid cleft-like structure with both a C- and a N-stereogenic center in high efficiency and selectivity. A variety of applications as a chiral organocatalyst and metallic catalyst precursors were demonstrated. Furthermore, DFT calculations suggest that the NH···O hydrogen bonding and weak interaction between the substrate and ligand are crucial for the excellent enantioselectivity control

    Additional file 1 of Establishment and validation of an immune infiltration predictive model for ovarian cancer

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    Additional file 1: Figure S1. Correlatio between IPM and patient survival. (A) Status distribution in high- and low group. (B) Correlation between risk score and survival

    An Organocatalytic System for <i>Z</i>‑Alkene Synthesis via a Hydrogen-Bonding-Assisted Photoinduced Electron Donor–Acceptor Complex

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    A general catalytic donor for the combination of a photoinduced electron donor–acceptor (EDA) complex and energy transfer was developed. This mild and metal-free protocol allows facile access to various Z-alkenes. Mechanism studies revealed that the organophotocatalyst, 4-CzIPN, formed a distinct three-component EDA complex with redox-active esters and (C6H5O)2P(O)OH to trigger the photoredox catalysis. The E → Z isomerization was achieved via electron exchange energy transfer from 4-CzIPN
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