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Yang M.,Tianjin University of Technology | Shen Z.,Tianjin University of Technology | Chen T.,Nankai University | Bi H.,Tianjin University of Technology | And 2 more authors.
Dalton Transactions | Year: 2013

A bottom-up approach is presented here for morphology control of Ln-asparagine (Asn) coordination polymers (CPs) from the macro to nanoscopic regime by tuning solvent polarity based on the π* solvent polarity scale in polar solvent-water mixed solutions. By a simple hydrothermal treatment, large macroporous spheres with sizes up to millimeters were obtained in ethanol (π*: 0.54)-water mixtures, and their formation mechanism was proved to be particle aggregation together with a hollowing process based on Ostwald ripening. Other solvents with increasing polarity were also used, and submicrometer spheres as well as fine nanoparticles were prepared in acetone (π*: 0.71) and DMF (π*: 0.88), respectively. When dioxane (π*: 0.55) was used here, whose π* value is similar to ethanol, large macroporous spheres were also prepared. Furthermore, with Ce- and La-Asn CPs large spheres as precursors, after calcination, ceria and lanthana large spheres with hierarchical structures were fabricated, respectively. Considering that many growth media of CPs are single solvent systems, designing certain solvents mixtures and tuning their polarity would bring us new opportunities to achieve morphology and composition control of CPs materials. © The Royal Society of Chemistry 2013.

Fu Q.,Peking University | Wang H.,Peking University | Lan Y.,Peking University | Li S.,Peking University | And 2 more authors.
Journal of Chromatography A | Year: 2014

A high-throughput biochemical detection method based on the combination of high-performance liquid chromatography (HPLC), multiple-stage mass spectrometry (MSn) and DNA-binding activity assay was developed and validated for the simultaneous screening and identification of DNA-binding compounds in complex samples. Palmatine was used as a sensitive, nontoxic and environmentally friendly DNA fluorescence probe. HPLC fingerprints, ultraviolet absorption spectra, MSn fragments of components, and DNA-binding activity profiles could be simultaneously recorded during real-time analysis. Using the proposed method, 25 compounds were identified from Lophatherum gracile Brongn extracts, of which 18 were novel compounds first identified in these extracts. Nineteen compounds showed DNA-binding activity, most of which were flavone glycosides, with distinct dose-effect and structure-activity relationships. The method was validated and was proven to have a good linearity in the range of concentrations used in the study. The limit of detection was 0.2020nmol. Our study indicated that the proposed method was sensitive, accurate, precise and reliable to be used for simultaneous screening and identification of DNA-binding compounds in complex samples. © 2013 Elsevier B.V.

Xu N.,Nanjing University | Guan S.,Nanjing Normal University | Chen Z.,Nanjing University | Yu Y.,CAS Institute of Zoology | And 8 more authors.
Journal of Pathology | Year: 2015

G protein-regulated cell function is crucial for cardiomyocytes, and any deregulation of its gene expression or protein modification can lead to pathological cardiac hypertrophy. Herein, we report that protein prenylation, a lipidic modification of G proteins that facilitates their association with the cell membrane, might control the process of cardiomyocyte hypertrophy. We found that geranylgeranyl diphosphate synthase (GGPPS), a key enzyme involved in protein prenylation, played a critical role in postnatal heart growth by regulating cardiomyocyte size. Cardiac-specific knockout of GGPPS in mice led to spontaneous cardiac hypertrophy, beginning from week 4, accompanied by the persistent enlargement of cardiomyocytes. This hypertrophic effect occurred by altered prenylation of G proteins. Evaluation of the prenylation, membrane association and hydrophobicity showed that Rheb was hyperactivated and increased mTORC1 signalling pathway after GGPPS deletion. Protein farnesylation or mTORC1 inhibition blocked GGPPS knockdown-induced mTORC1 activation and suppressed the larger neonatal rat ventricle myocyte size and cardiomyocyte hypertrophy in vivo, demonstrating a central role of the FPP-Rheb-mTORC1 axis for GGPPS deficiency-induced cardiomyocyte hypertrophy. The sustained cardiomyocyte hypertrophy progressively provoked cardiac decompensation and dysfunction, ultimately causing heart failure and adult death. Importantly, GGPPS was down-regulated in the hypertrophic hearts of mice subjected to transverse aortic constriction (TAC) and in failing human hearts. Moreover, HPLC-MS/MS detection revealed that the myocardial farnesyl diphosphate (FPP):geranylgeranyl diphosphate (GGPP) ratio was enhanced after pressure overload. Our observations conclude that the alteration of protein prenylation promotes cardiomyocyte hypertrophic growth, which acts as a potential cause for pathogenesis of heart failure and may provide a new molecular target for hypertrophic heart disease clinical therapy. © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Zhu G.-T.,Wuhan University | Li X.-S.,Wuhan University | Gao Q.,Wuhan University | Zhao N.-W.,Shimadzu China Co. | And 2 more authors.
Journal of Chromatography A | Year: 2012

In this work, we describe a novel synthetic strategy of magnetic mesoporous silica spheres (Fe 3O 4@mSiO 2) for the selective enrichment of endogenous peptides. Fe 3O 4 particles were coated with silica shell by a sol-gel method, followed by pseudomorphic synthesis to transform nonporous silica shell into ordered mesoporous silica shell. The core/shell structure and mesostructure were individually fabricated in two steps, which can be expedient to independently optimize the properties of monodispersion, magnetization and mesostructure. Actually, it was confirmed that the produced Fe 3O 4@mSiO 2 particles possess good monodispersion, high magnetization, superparamagnetism, uniform accessible mesopores, and large surface area and pore volume. With these good properties, Fe 3O 4@mSiO 2 spheres were applied to the rapid enrichment of peptides. Based on the size-exclusion mechanism and hydrophobic interaction with siloxane bridge group mainly on the surface of inside pores, Fe 3O 4@mSiO 2 can selectively capture peptides and exclude high-MW proteins and salts. Furthermore, peptides in human plasma were successfully enriched by Fe 3O 4@mSiO 2. © 2011 Elsevier B.V.

He H.-B.,Shanghai University | Li B.,Shanghai University | Dong J.-P.,Shanghai University | Lei Y.-Y.,Shanghai University | And 4 more authors.
ACS Applied Materials and Interfaces | Year: 2013

A functionalizable organosiliceous hybrid magnetic material was facilely constructed by surface polymerization of octavinyl polyhedral oligomeric silsesquioxane (POSS) on the Fe3O4 nanoparticles. The resultant Fe3O4@POSS was identified as a mesoporous architecture with an average particle diameter of 20 nm and high specific surface area up to 653.59 m2 g-1. After it was tethered with an organic chain containing dithiol via thiol-ene addition reaction, the ultimate material (Fe3O4@POSS-SH) still have moderate specific area (224.20 m2 g-1) with almost identical porous morphology. It turns out to be a convenient, efficient single adsorbent for simultaneous elimination of inorganic heavy metal ions and organic dyes in simulate multicomponent wastewater at ambient temperature. The Fe 3O4@POSS-SH nanoparticles can be readily withdrawn from aqueous solutions within a few seconds under moderate magnetic field and exhibit good stability in strong acid and alkaline aqueous matrices. Contaminants-loaded Fe3O4@POSS-SH can be easily regenerated with either methanol-acetic acid (for organic dyes) or hydrochloric acid (for heavy metal ions) under ultrasonication. The renewed one keeps appreciable adsorption capability toward both heavy metal ions and organic dyes, the removal rate for any of the pollutants exceeds 92% to simulate wastewater with multiple pollutants after repeated use for 5 cycles. Beyond the environmental remediation function, thanks to the pendant vinyl groups, the Fe3O4@POSS derived materials rationally integrating distinct or versatile functions could be envisaged and consequently a wide variety of applications may emerge. © 2013 American Chemical Society.

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