15 research outputs found

    The view from China: Russia as seen by two Chinese scholars of russia

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    ISSN:1863-042

    Molecular phylogeny suggests synonymy of Sandalia bridgesi within Sandalia triticea (Gastropoda: Ovulidae)

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    The Ovulidae are the most ecologically diverse family of the order Littorinimorpha. And the Sandalia is a small genus containing only three species. In the present study, we collected 44 specimens of Ovulidae (Gastropoda: Cypraeacea), belonging to six genera and eight species, including 20 Sandalia bridgesi and 2 Sandalia triticea individuals. The cytochrome c oxidase I gene (COI), 16S rRNA, and ITS1-5.8S-ITS2 sequences were obtained from the specimens and compared with sequences downloaded from GenBank to calculate genetic distances and construct phylogenetic trees. The sequences of S. bridgesi and S. triticea exhibited a high degree of similarity, and the S. bridgesi does not formed a separate clade, supporting the proposition that S. bridgesi should be considered a synonym of S. triticea

    ï»żMolecular phylogeny suggests synonymy of Sandalia bridgesi Lorenz, 2009 with S. triticea (Lamarck, 1810) (Gastropoda, Ovulidae)

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    The Ovulidae (Gastropoda, Cypraeoidea) is a family of small to medium Mollusca in the order Littorinimorpha, and Sandalia is a very small genus containing only three extant species. In the present study, 132 specimens of Ovulidae were collected, belonging to seven genera and nine species, including 54 Sandalia bridgesi and three Sandalia triticea individuals. The cytochrome c oxidase I gene, 16S rRNA, and ITS1-5.8S-ITS2 sequences were obtained from all specimens and compared with sequences downloaded from GenBank to calculate genetic distances and construct phylogenetic trees. The sequences of S. bridgesi and S. triticea exhibited a high degree of similarity, and S. bridgesi does not form a separate clade, supporting the proposal that S. bridgesi should be synonymised with S. triticea

    Mitigation of Lost Circulation in Oil-Based Drilling Fluids Using Oil Absorbent Polymers

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    In order to mitigate the loss circulation of oil-based drilling fluids (OBDFs), an oil-absorbent polymer (OAP) composed by methylmethacrylate (MMA), butyl acrylate (BA), and hexadecyl methacrylate (HMA) was synthesized by suspension polymerization and characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electronic microscopy (SEM). The oil-absorptive capacity of OAP under different solvents was measured as the function of temperature and time. The effect of the OAP on the rheological and filtration properties of OBDFs was initially evaluated, and then the sealing property of OAP particles as lost circulation materials (LCMs) was examined by a high-temperature and high-pressure (HTHP) filtration test, a sand bed filtration test, a permeable plugging test, and a fracture sealing testing. The test results indicated that the addition of OAP had relatively little influence on the rheological properties of OBDF at content lower than 1.5 w/v % but increased the fluid viscosity remarkably at content higher than 3 w/v %. It could reduce the HTHP filtration and improve the sealing capacity of OBDF significantly. In the sealing treatment, after addition into the OBDF, the OAP particles could absorb oil accompanied with volume enlargement, which led to the increase of the fluid viscosity and slowing down of the fluid loss speed. The swelled and deformable OAP particles could be squeezed into the micro-fractures with self-adoption and seal the loss channel. More important, fluid loss was dramatically reduced when OAP particles were combined with other conventional LCMs by a synergistic effect

    Preparation and Properties of High-Temperature-Resistant, Lightweight, Flexible Polyimide Foams with Different Diamine Structures

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    Polyimide foam (PIF) is a rising star in high-end applications such as aerospace thermal insulation and military sound absorption. However, the basic rule on molecular backbone design and uniform pore formation of PIF still need to be explored. In this work, polyester ammonium salt (PEAS) precursor powders are synthesized between alcoholysis ester of 3, 3â€Č, 4, 4â€Č-benzophenone tetracarboxylic dianhydride (BTDE) and aromatic diamines with different chain flexibility and conformation symmetry. Then, a standard “stepwise heating” thermo-foaming approach is used to prepare PIF with comprehensive properties. A rational thermo-foaming program is designed based on in situ observation of pore formation during heating. The fabricated PIFs have uniform pore structure, and PIFBTDA-PDA shows the smallest size (147 ÎŒm) and narrow distribution. Interestingly, PIFBTDA-PDA also presents a balanced strain recovery rate (SR = 91%) and mechanical robustness (0.051 MPa at 25% strain) and its pore structure maintains regularity after 10 compression–recovery cycles, mainly due to high rigidity of the chains. Furthermore, all the PIFs possess lightweight feature (15–20 kg∙m−3), good heat resistance (Tg at 270–340 °C), thermal stability (T5% at 480–530 °C), thermal insulation properties (λ = 0.046–0.053 W∙m−1K−1 at 20 °C, λ = 0.078–0.089 W∙m−1K−1 at 200 °C), and excellent flame retardancy (LOI > 40%). The reported monomer-mediated pore-structure control strategy can provide guidelines for the preparation of high-performance PIF and its industrial applications

    A whole genome scanning for quantitative trait loci on traits related to sperm quality and ejaculation in pigs

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    To identify quantitative trait loci (QTL) for traits related to semen and ejaculation, phenotype data including semen volume, sperm concentration, total sperm per ejaculate, sperm motility, sperm abnormality rate, semen pH value, ejaculation times and ejaculation duration were measured on 206 F(2) boar at 240 days in a White Duroc x Erhualian intercross. A genome-wide scan was performed and the entire White Duroc x Erhualian intercross was genotyped for 183 microsatellite markers covering the whole pig genome. QTL analysis was performed using a composite regression interval mapping method via QTLExpress. A total of 18 QTL were detected, including 4 genome-wide significant QTL each for semen pH on pig chromosome (SSC) 2 and SSC12, for semen volume on SSC15, and for ejaculation times on SSC17. Fourteen suggestive QTL were found on SSC1, 2,3, 4,6,9,17 and 18. To our knowledge, this is the first report about the QTL for semen and ejaculation traits in pigs, providing a start point to decipher the genetic basis of these complex traits. (c) 2008 Elsevier B.V. All rights reserved

    Combined Photodynamic and Photothermal Therapy Using Cross-Linked Polyphosphazene Nanospheres Decorated with Gold Nanoparticles

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    A rational combination of photodynamic therapy (PDT) and photothermal therapy (PTT) could achieve a synergistic therapeutic effect to enhance therapeutic efficacy in the cancer treatment. Herein, polyphosphazene nanospheres as a novel kind of photosensitizer carriers were synthesized by anchoring and isolating photosensitizing porphyrin monomers covalently in the cross-linked structure. Gold nanoparticles were then immobilized on the surface of the nanospheres to introduce the photothermal performance. The hybrid system was eventually conjugated by polyethylene glycol to decrease its cytotoxicity. The morphology analysis showed that the nanospheres were covered by homogeneously dispersed gold nanoparticles. In this way, the resulted system could afford efficient photodynamic and photothermal effect simultaneously, as confirmed by the cancer cell killing studies. The cell experiments demonstrated that the as-prepared polyphosphazene nanospheres with inherent fluorescence could be internalized by HeLa cells, showing high performance of combined PDT and PTT under suitable light irradiation. Thus, this integrated system presents its effectiveness to achieve combined PDT and PTT for enhanced cancer therapeutics

    An overview of meta-analyses on radiomics: more evidence is needed to support clinical translation

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    Abstract Objective To conduct an overview of meta-analyses of radiomics studies assessing their study quality and evidence level. Methods A systematical search was updated via peer-reviewed electronic databases, preprint servers, and systematic review protocol registers until 15 November 2022. Systematic reviews with meta-analysis of primary radiomics studies were included. Their reporting transparency, methodological quality, and risk of bias were assessed by PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) 2020 checklist, AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews, version 2) tool, and ROBIS (Risk Of Bias In Systematic reviews) tool, respectively. The evidence level supporting the radiomics for clinical use was rated. Results We identified 44 systematic reviews with meta-analyses on radiomics research. The mean ± standard deviation of PRISMA adherence rate was 65 ± 9%. The AMSTAR-2 tool rated 5 and 39 systematic reviews as low and critically low confidence, respectively. The ROBIS assessment resulted low, unclear and high risk in 5, 11, and 28 systematic reviews, respectively. We reperformed 53 meta-analyses in 38 included systematic reviews. There were 3, 7, and 43 meta-analyses rated as convincing, highly suggestive, and weak levels of evidence, respectively. The convincing level of evidence was rated in (1) T2-FLAIR radiomics for IDH-mutant vs IDH-wide type differentiation in low-grade glioma, (2) CT radiomics for COVID-19 vs other viral pneumonia differentiation, and (3) MRI radiomics for high-grade glioma vs brain metastasis differentiation. Conclusions The systematic reviews on radiomics were with suboptimal quality. A limited number of radiomics approaches were supported by convincing level of evidence. Clinical relevance statement The evidence supporting the clinical application of radiomics are insufficient, calling for researches translating radiomics from an academic tool to a practicable adjunct towards clinical deployment. Graphical Abstrac
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