Search results for "amor"

Amorphous Calcium Phosphates: Solvent-Controlled Growth and Stabilization through the Epoxide Route.

2020

Calcium phosphates stand among the most promising nanobiomaterials in key biomedical applications, such as bone repairment, signalling or drug/gene delivery. Their intrinsic properties as crystalline structure, composition, particle shape and size define their successful use. Among these compounds, metastable amorphous calcium phosphate (ACP) is currently gaining particular attention due to its inherently high reactivity in solution, which is crucial in bone development mechanisms. However, the preparation of this highly desired (bio)material with control over its shape, size and phase purity remains as a synthetic challenge. In this work, the epoxide route was adapted for the synthesis of …

Crystallized nano-sized alpha-tricalcium phosphate from amorphous calcium phosphate: microstructure, cementation and cell response

2015

New insight on the conversion of amorphous calcium phosphate (ACP) to nano-sized alpha tricalcium phosphate (α-TCP) provides a faster pathway to calcium phosphate bone cements. In this work, synthesized ACP powders were treated with either water or ethanol, dried, crystallized between 700 and 800 °C, and then cooled at different cooling rates. Particle size was measured in a scanning electron microscope, but crystallite size calculated by Rietveld analysis. Phase composition and bonding in the crystallized powder was assessed by x-ray diffraction and Fourier-transform infrared spectroscopy. Results showed that 50 nm sized α-TCP formed after crystallization of lyophilized powders. Water trea…

Amorphous polyphosphate/amorphous calcium carbonate implant material with enhanced bone healing efficacy in a critical-size defect in rats

2016

In this study the effect of amorphous calcium carbonate (ACC) microparticles and amorphous calcium polyphosphate (polyP) microparticles (termed aCa-polyP-MP) on bone mineral forming cells/tissue was investigated in vitro and in vivo. The ACC particles (termed ACC-P10-MP) were prepared in the presence of Na-polyP. Only the combinations of polyP and ACC microparticles enhanced the proliferation rate of human mesenchymal stem cells (MSCs). Gene expression studies revealed that ACC causes an upregulation of the expression of the cell membrane-associated carbonic anhydrase IX (CA IX; formation of ACC), while the transcript level of the alkaline phosphatase (ALP; liberation of orthophosphate from…

Nonenzymatic Transformation of Amorphous CaCO3 into Calcium Phosphate Mineral after Exposure to Sodium Phosphate in Vitro: Implications for in Vivo H…

2015

Studies indicate that mammalian bone formation is initiated at calcium carbonate bioseeds, a process that is driven enzymatically by carbonic anhydrase (CA). We show that amorphous calcium carbonate (ACC) and bicarbonate (HCO3 (-) ) cause induction of expression of the CA in human osteogenic SaOS-2 cells. The mineral deposits formed on the surface of the cells are rich in C, Ca and P. FTIR analysis revealed that ACC, vaterite, and aragonite, after exposure to phosphate, undergo transformation into calcium phosphate. This exchange was not seen for calcite. The changes to ACC, vaterite, and aragonite depended on the concentration of phosphate. The rate of incorporation of phosphate into ACC, …

Postfazione

2011

Recensione di Brancaccio L., Castellano C.(a cura di), Affari di camorra. Famiglie, imprenditori e gruppi criminali, Donzelli, Roma, 2015

2017

Volume collettaneo, risultato di un'importante ricerca interdisciplinare sulla camorra e sulla criminalità organizzata

Recensione di Carolina Castellano, Una questione di provincia. Criminalità e camorra tra età giolittiana e fascismo, Editoriale Scientifica, Napoli, …

2021

Il volume Una questione di provincia, pubblicato nel 2020 dalla napoletana editoriale Scienti fica, si concentra sull’analisi delle «forme peculiari della criminalità camorrista» (p. 15) tra età giolittiana e fascismo nell’area dell’agro napoletano estesa fra le pendici del Vesuvio e la piana di nola, la piana del Volturno e l’area intorno ad Aversa.

Carolina Castellano, Una questione di provincia. Criminalità e camorra tra età giolittiana e fascismo, Napoli, Editoriale Scientifica, 2021, pp. 166.

2023

Apoptosis: focus on sea urchin development

2009

It has been proposed that the apoptosis is an essential requirement for the evolution of all animals, in fact the apoptotic program is highly conserved from nematodes to mammals. Throughout development, apoptosis is employed by multicellular organisms to eliminate damaged or unnecessary cells. Here, we will discuss both developmental programmed cell death (PCD) under normal conditions and stress induced apoptosis, in sea urchin embryos. Sea urchin represent an excellent model system for studying embryogenesis and cellular processes involved in metamorphosis. PCD plays an essential role in sculpting and remodelling the embryos and larvae undergoing metamorphosis. Moreover, this marine organi…

Monte Carlo Simulations of Surfaces and Interfaces in Materials

1996

Many applications of materials are controlled by their surface and interface properties. In particular, metallic alloys (but also mixed dielectric materials and amorphous polymer blends) are not homogeneously mixed on a microscopic length scale, although they are macroscopically homogeneous. Depending on the preparation of the sample, there exists a heterophase microstructure, with typical domain sizes, e.g. in the 1 to 102 µm range, separated by interfaces between them. The physical properties of such intrinsic interfaces (grain boundaries between small crystallites, antiphase domain boundaries in ordered alloys, Bloch walls in magnetic materials, etc.) are not only an important controllin…