目的建立通过力学表型来灵敏反映人间充质干细胞分化早期微小力学性质变化的技术。方法使用基于原子力显微镜峰值力定量纳米力学作图(peak force quantitative nanomechanical mapping,PF-QNM)技术,测量在不同浓度氯化锂诱导下人间充质...目的建立通过力学表型来灵敏反映人间充质干细胞分化早期微小力学性质变化的技术。方法使用基于原子力显微镜峰值力定量纳米力学作图(peak force quantitative nanomechanical mapping,PF-QNM)技术,测量在不同浓度氯化锂诱导下人间充质干细胞的力学变化过程。结果 4mmol/L和30mmol/L氯化锂处理干细胞48h后其纳米力谱就有显著的差异;但要到72h之后,平均杨氏模量才能区分不同浓度氯化锂处理所导致的差别。结论纳米力谱比平均杨氏模量更能反映干细胞分化早期的力学性质变化。基于纳米力谱的力学表型可以作为物理生物学标记来鉴定干细胞的早期分化。展开更多
A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R...A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. 【展开更多
Peptoids(or poly-N-substituted glycines)are a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis,high chemical stability,enzyme hydrolysis resistance,and biocompatibility....Peptoids(or poly-N-substituted glycines)are a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis,high chemical stability,enzyme hydrolysis resistance,and biocompatibility.By tuning the side chain chemistry of peptoids,it allows for precise control over sequences and achieving a large side-chain diversity.Due to these unique features,in the last several years,many amphiphilic peptoids were designed as highly tunable building blocks for the preparation of biomimetic nanomaterials with well-defined hierarchical structures and desired functionalities.Herein,we provide an overview of the recent achievements in this area by dividing them into the following three aspects.First,mica-and silica-templated peptoid selfassembly are summarized.The presence of inorganic substrates provides the guarantee of investigating their selfassembly mechanisms and interactions between peptoids and substrates using nanoscale characterization techniques,particularly in situ atomic force microscopy(AFM)and AFMbased dynamic force spectroscopy(AFM-DFS).Second,solution-phase self-assembly of peptoids into nanotubes and nanosheets is presented,as well as their self-repair properties.Third,the applications of peptoid-based nanomaterials are outlined,including the construction of catalytic nanomaterials as a template and cytosolic delivery as cargoes.展开更多
In this study, a sensitive and rapid LC-MS/MS method was developed and validated to determine dabigatran in plasma of beagle dogs after oral administration of dabigatran etexilate nanosuspension （DABE-NS）. The analy...In this study, a sensitive and rapid LC-MS/MS method was developed and validated to determine dabigatran in plasma of beagle dogs after oral administration of dabigatran etexilate nanosuspension （DABE-NS）. The analytes （dabigatran） and sertraline hydrochloride （internal standard, IS） were separated on a Kromasil C18 column using gradient elution consisting of methanol and formate buffer at a flow rate of 0.4 mL/min in 20 min. Detection and quantitation were carded out by multiple reaction monitoring following the transitions： m/z 472.17→289.07 and 305.98→275.00 for dabigatran and IS at positive ion mode, respectively. The calibration curves were linear from 1.0 to 500.0 ng/mL for dabigatran with r = 0.9995. The accuracy of each analyte ranged from 94.8% to 107.1%, and the precision was within 6%. Besides, this method was successfully applied in the investigation of the pharmacokinetic profile of dabigatran in beagle dogs after oral administration of DABE-NS. The maximum concentration and the areas under curves of dabigatran for DABE-NS were significantly higher than those of control formulation, indicating improved oral absorption.展开更多
文摘A new experimental measurement of residual stresses around Vickers′ indentations on the surface of the SiC/Al 2O 3 nanocomposites is proposed with the aid of a Raman microprobe. Results s how that the shifts of R lines in the fluorescence spectra va ry with the distance from the centre of indentation. The magnitude of load appli ed on the surface of the materials through the indenter influences the shifts of R lines to great extent. The luminescence of R lines of the materials before indenting is used to determine the residual stresses around the indentation in the materials, assuming that the stress tensor is transversely isotropic. Final ly, the term of hydrostatic stress is adopted to explain and compare different residual stresses around indentations with the increase of the indenting load an d the distance from the centre of indentations. 【
基金supported by the Startup Research Fund of Dongguan University of Technology(KCYKYQD2017015)the US Department of Energy,Office of Science,Office of Basic Energy Sciences,as part of the Energy Frontier Research Centers program:CSSAS—The Center for the Science of Synthesis Across Scales(DESC0019288)。
文摘Peptoids(or poly-N-substituted glycines)are a promising class of bioinspired sequence-defined polymers due to their highly efficient synthesis,high chemical stability,enzyme hydrolysis resistance,and biocompatibility.By tuning the side chain chemistry of peptoids,it allows for precise control over sequences and achieving a large side-chain diversity.Due to these unique features,in the last several years,many amphiphilic peptoids were designed as highly tunable building blocks for the preparation of biomimetic nanomaterials with well-defined hierarchical structures and desired functionalities.Herein,we provide an overview of the recent achievements in this area by dividing them into the following three aspects.First,mica-and silica-templated peptoid selfassembly are summarized.The presence of inorganic substrates provides the guarantee of investigating their selfassembly mechanisms and interactions between peptoids and substrates using nanoscale characterization techniques,particularly in situ atomic force microscopy(AFM)and AFMbased dynamic force spectroscopy(AFM-DFS).Second,solution-phase self-assembly of peptoids into nanotubes and nanosheets is presented,as well as their self-repair properties.Third,the applications of peptoid-based nanomaterials are outlined,including the construction of catalytic nanomaterials as a template and cytosolic delivery as cargoes.
基金The National Basic Research Program of China(Grant No.2015CB932100)
文摘In this study, a sensitive and rapid LC-MS/MS method was developed and validated to determine dabigatran in plasma of beagle dogs after oral administration of dabigatran etexilate nanosuspension （DABE-NS）. The analytes （dabigatran） and sertraline hydrochloride （internal standard, IS） were separated on a Kromasil C18 column using gradient elution consisting of methanol and formate buffer at a flow rate of 0.4 mL/min in 20 min. Detection and quantitation were carded out by multiple reaction monitoring following the transitions： m/z 472.17→289.07 and 305.98→275.00 for dabigatran and IS at positive ion mode, respectively. The calibration curves were linear from 1.0 to 500.0 ng/mL for dabigatran with r = 0.9995. The accuracy of each analyte ranged from 94.8% to 107.1%, and the precision was within 6%. Besides, this method was successfully applied in the investigation of the pharmacokinetic profile of dabigatran in beagle dogs after oral administration of DABE-NS. The maximum concentration and the areas under curves of dabigatran for DABE-NS were significantly higher than those of control formulation, indicating improved oral absorption.
