Enhancement of Hydroxyapatite Dissolution through Krypton Ion Irradiation

International audienceHydroxyapatite (HA) synthesized by a wet chemical route was subjected to heavy ion irradiation, using 4 MeV Krypton ions (Kr 17+) with ion fluence ranging from 1×10 13 to 1×10 15 ions/cm 2. Glancing incidence X-ray diffraction (GIXRD) results confirmed the phase purity of irradiated HA with a moderate contraction in lattice parameters, and further indicated irradiation-induced structural disorder, evident by a broadening of diffraction peaks. High-resolution transmission electron microscopy (HRTEM) observations indicated that the applied Kr irradiation induced significant damage in the hydroxyapatite lattice. Specifically, cavities were observed with their diameter and density varying with irradiation fluences while a radiation-induced crystalline-to-amorphous transition with increasing ion dose was identified. Raman and X-ray photoelectron spectroscopy (XPS) analysis further indicated the presence of irradiation-induced defects. Compositional analysis of pristine and irradiated materials following immersion in Tris (pH 7.4, 37℃) buffer showed that dissolution in vitro was enhanced by irradiation, reaching a peak for 0.1dpa. We examined the effects of irradiation on the early stages of the mouse osteoblast-like cells (MC3T3-E) response. A cell counting kit-8 assay (CCK-8 test) was carried out to investigate the cytotoxicity of samples, and viable cells can be observed on the irradiated materials.L'hydroxyapatite (HA) synthétisée par voie chimique a été soumise à une irradiation ionique lourde, en utilisant des ions Krypton 4 MeV (Kr 17+) avec une fluence ionique allant de 1 × 10 13 à 1 × 10 15 ions / cm 2. Incidence du regard X- Les résultats de la diffraction des rayons (GIXRD) ont confirmé la pureté de phase de l'AH irradié avec une contraction modérée des paramètres du réseau et ont en outre indiqué un trouble structurel induit par l'irradiation, évident par un élargissement des pics de diffraction. Des observations en microscopie électronique à transmission à haute résolution (HRTEM) ont indiqué que l'irradiation au Kr appliquée a induit des dommages importants dans le réseau d'hydroxyapatite. Plus précisément, des cavités ont été observées avec leur diamètre et leur densité variant avec les fluences d'irradiation tandis qu'une transition cristalline-amorphe induite par le rayonnement avec une dose ionique croissante a été identifiée. L'analyse par spectroscopie photoélectronique Raman et X (XPS) a en outre indiqué la présence de défauts induits par l'irradiation. L'analyse de la composition des matériaux vierges et irradiés après immersion dans du tampon Tris (pH 7,4, 37 ℃) a montré que la dissolution in vitro était améliorée par irradiation, atteignant un pic de 0,1 dpa. Nous avons examiné les effets de l'irradiation sur les premiers stades de la réponse des cellules de type ostéoblaste de souris (MC3T3-E). Un test de comptage de cellules kit 8 (test CCK-8) a été réalisé pour étudier la cytotoxicité des échantillons, et des cellules viables peuvent être observées sur les matériaux irradiés

A multiple coating route to hollow carbon spheres with foam-like shells and their applications in supercapacitor and confined catalysis

Fang, XL (通讯作者)Recent advances in the sol-gel process derived resorcinol-formaldehyde (RF) coating strategies offer new opportunities for the synthesis and applications of hollow carbon spheres (HCS). Due to the lack of an effective route for controlling the pore structures, the synthesis of RF resin derived HCS with a high specific surface area for promising applications is still a challenge. In this work, we present a facile and effective template-directed multiple coating route to synthesize RF resin derived HCS with foam-like shells (HCSF). The as-synthesized HCSF exhibit a significantly higher specific surface area (1286 m(2) g(-1)) and larger pore volumes (2.25 cm(3) g(-1)) than the RF resin derived HCS (639 m(2) g(-1) and 0.56 cm(3) g(-1)). Our experiments demonstrated that the cationic surfactant CTAB plays a critical role in forming the foam-like pore structure. Compared with the RF resin derived HCS, the as-synthesized HCSF show advantageous performances in supercapacitor and confined catalysis due to their unique pore structures.NSFC 21301144 21131005 21333008 20925103 21021061 MOST of China 2011CB93240

An Amorphous Carbon Nitride Composite Derived from ZIF-8 as Anode Material for Sodium-Ion Batteries

通讯作者地址: Fan, JMAn composite comprising amorphous carbon nitride (ACN) and zinc oxide is derived from ZIF-8 by pyrolysis. The composite is a promising anode material for sodium-ion batteries. The nitrogen content of the ACN composite is as high as 20.4%, and the bonding state of nitrogen is mostly pyridinic, as determined by X-ray photoelectron spectroscopy (XPS). The composite exhibits an excellent Na+ storage performance with a reversible capacity of 430mAhg(-1) and 146mAhg(-1) at current densities of 83mAg(-1) and 8.33Ag(-1), respectively. A specific capacity of 175mAhg(-1) was maintained after 2000 cycles at 1.67Ag(-1), with only 0.016% capacity degradation per cycle. Moreover, an accelerating rate calorimetry (ARC) test demonstrates the excellent thermal stability of the composite, with a low self heating rate and high onset temperature (210 degrees C). These results shows its promise as a candidate material for high-capacity, high-rate anodes for sodium-ion batteries.National 973 Program 2015CB251102 Key Project of NSFC U1305246 2132106

The synthesis of a core-shell MnO2/3D-ordered hollow carbon sphere composite and its superior electrochemical capability for lithium ion batteries

NSFC [U1305246, 21321062]; Xiamen city [3502Z20121002

Anti-metastatic and differential effects on protein expression of epigallocatechin-3-gallate in HCCLM6 hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third highest cause of cancer-related mortality in humans. Epigallocatechin-3-gallate (EGCG) has been shown to inhibit the metastatic activity of certain cancer cells. The aim of this study was to determine the effects and molecular mechanism(s) of action of EGCG in human HCC cells. A migration and invasion assay for the metastatic behavior of HCCLM6 cells was performed. The anti-metastatic effects of EGCG were investigated by RT-PCR and gelatin zymography. A total cellular protein profile was obtained using 2-dimensional gel electrophoresis (2-DE), followed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) analyses of proteins with significant differences in expression following treatment with EGCG. The results revealed that EGCG induced apoptosis and inhibited the metastasis of HCCLM6 cells. The anti-metastatic effects of EGCG were associated with the inhibition of matrix metalloproteinase (MMP)-2 and MMP-9 activity. The expression levels of far upstream element (FUSE) binding protein 1 (FUBP1), heat shock protein beta 1 (HSPB1), heat shock 60 kDa protein 1 (chaperonin) (CH60) and nucleophosmin (NPM) proteins, which are associated with metastasis, were significantly altered in the EGCG-treated HCCLM6 cells. The data from the present study suggest that EGCG has potential as a therapeutic agent for the treatment of HCC

Micromechanics of liquid-phase exfoliation of a layered 2D material: A hydrodynamic peeling model

We present a micromechanical analysis of flow-induced peeling of a layered 2D material suspended in a liquid, for the first time accounting for realistic hydrodynamic loads. In our model, fluid forces trigger a fracture of the inter-layer interface by lifting a flexible “flap” of nanomaterial from the surface of a suspended microparticle. We show that the so far ignored dependence of the hydrodynamic load on the wedge angle produces a transition in the curve relating the critical fluid shear rate for peeling to the non-dimensional adhesion energy. For intermediate values of the non-dimensional adhesion energy, the critical shear rate saturates, yielding critical shear rate values that are drastically smaller than those predicted by a constant load assumption. Our results highlight the importance of accounting for realistic hydrodynamic loads in fracture mechanics models of liquid-phase exfoliation.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Energy Technolog

Precisely controlled resorcinol-formaldehyde resin coating for fabricating core-shell, hollow, and yolk-shell carbon nanostructures

MOST of China [2011CB932403, 2009CB930703]; NSFC [21131005, 21021061, 20925103, 20923004]; Fok Ying Tung Education Foundation [121011]This work provides a facile one-step sol-gel route to synthesize high-quality resorcinol-formaldehyde (RF) resin coated nanocomposites that can be further used to fabricate desired carbon nanostructures. Colloidal particles with different morphologies and sizes can be coated with high-quality RF resin shells by the proposed cationic surfactant assisted RF resin coating strategy. The as-synthesized RF resin coated nanocomposites are ideal candidates for selective synthesis of core-shell, hollow, and yolk-shell carbon nanostructures. Based on the carboxylic functional RF resin coating, graphitic carbon nanostructures can also be synthesized by employing the graphitization catalyst. The as-synthesized carbon nanostructures show the advantageous performances in several applications. Hollow carbon spheres are potential electrode materials for lithium-sulfur batteries. Hollow graphitic spheres are promising catalyst supports for oxygen reduction reaction. And yolk-shell structured Au@HCS nanoreactors with ultrathin shells exhibit high catalytic activity and recyclability in confined catalysis

Identification of DYNLT1 associated with proliferation, relapse, and metastasis in breast cancer

BackgroundBreast cancer (BC) is the most common malignant disease worldwide. Although the survival rate is improved in recent years, the prognosis is still bleak once recurrence and metastasis occur. It is vital to investigate more efficient biomarkers for predicting the metastasis and relapse of BC. DYNLT1 has been reported that participating in the progression of multiple cancers. However, there is still a lack of study about the correlation between DYNLT1 and BC.MethodsIn this study, we evaluated and validated the expression pattern and prognostic implication of DYNLT1 in BC with multiple public cohorts and BC tumor microarrays (TMAs) of paraffin-embedded tissues collected from the Affiliated Hospital of Jining Medical University. The response biomarkers for immune therapy, such as tumor mutational burden (TMB), between different DYNLT1 expression level BC samples were investigated using data from the TCGA-BRCA cohort utilizing public online tools. In addition, colony formation and transwell assay were conducted to verify the effects of DYNLT1 in BC cell line proliferation and invasion.ResultsThe results demonstrated that DYNLT1 overexpressed in BC and predicted poor relapse-free survival in our own BC TMA cohort. In addition, DYNLT1 induced BC development by promoting MDA-MB-231 cell proliferation migration, and metastasis.ConclusionAltogether, our findings proposed that DYNLT1 could be a diagnostic and prognostic indicator in BC

The neurobiology of attention deficit/hyperactivity disorder.

ADHD is a brain based disorder with structural and functional abnormalities in widespread but specific areas of the brain. The most significant and consistent structural imaging findings include smaller total brain volumes, and reduced volumes in the right frontal lobe, right parietal cortex, caudate nucleus, cerebellar hemispheres, and posterior-inferior lobules of the cerebellar vermis. ADHD involves hypofunction of catecholaminergic circuits, particularly those that project to the prefrontal cortex. A minimum of 18 genes have been reported to be associated with the disorder; among them the DRD4 7-repeat allele has been found associated with a thinner prefrontal and posterior parietal cortex. Epigenetic factors acting during critical periods of prenatal and postnatal development may interact with genetic determinants. Methylphenidate, as well as the catecholaminergic nonstimulant atomoxetine, are effective in improving ADHD symptoms

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO