Search results for "Silicates"
showing 10 items of 98 documents
Orientation of charged clay nanotubes in evaporating droplet meniscus.
2015
© 2014 Elsevier Inc. During drying, an aqueous suspension of strongly charged halloysite clay nanotubes concentrates at the edge of the droplet ("coffee-ring" effect) which provides alignment of the tubes along the liquid-substrate contact line. First, the surface charge of the nanotubes was enhanced by polyanion adsorption inside of the lumen to compensate for the internal positive charges. This increased the magnitude of the ξ-potential of the tubes from -36 to -81mV and stabilized the colloids. Then, colloidal halloysite was dropped onto the substrate, dried at 65°C and after a concentration of ~0.05mgmL-1 was reached, the alignment of nanotubes occurred starting from the droplet edges. …
Differentiation capacity of epithelial cells in the sponge Suberites domuncula.
2004
Sponges (phylum Porifera) represent the oldest metazoans. Their characteristic metazoan adhesion molecules and transcription factors enable them to establish a complex "Bauplan" ; three major differentiated cell types (epithelial cells, skeletal cells/sclerocytes, and contractile cells) can be distinguished. Since no molecular markers are as yet available to distinguish these somatic cells or the corresponding embryonic cells from which they originate, we have selected the following three genes for their characterization: noggin (a signaling molecule in development), a caspase that encodes an apoptotic molecule, and silicatein. Silicatein is an enzyme that is involved in the synthesis of si…
Sodium zirconium cyclosilicate: a new potassium binder for the treatment of hyperkalemia
2018
Hyperkalemia is one of the most common electrolyte disturbances, especially among some groups of patients, such as in those with chronic kidney disease, diabetes or heart failure. Hyperkalemia has been associated with increased risks of mortality, arrhythmias, hospitalization and costs, as well as the need to down titrate/discontinue renin-angiotensin-aldosterone system inhibitors (RAASIs), despite their well-known cardiovascular and nephroprotective benefits. Current potassium binders have limitations (slow onset of action, limited selectivity for potassium binding, risk of drug interactions or gastrointestinal intolerance). Sodium zirconium cyclosilicate (SZC) is a new potassium binder re…
Evaluation of changes in ion release and biological properties of NeoMTA‐Plus and Endocem‐MTA exposed to an acidic environment
2018
AIM To analyse in vitro changes in ion release and biological properties of Endocem-MTA (Maruchi, Wonju, Korea) and NeoMTA-Plus (Avalon Biomed Inc, Bradenton, FL, USA) exposed to acidic or neutral environment on human dental periodontal ligament stem cells (hPDLSCs). METHODOLOGY Cell viability and wound healing assays were performed using eluates of each material. Cell death and changes in phenotype induced by the set endodontic sealer eluates were evaluated through flow cytometry. To evaluate cell attachment to the different materials, hPDLSCs were directly seeded onto the material surfaces and analysed by scanning electron microscopy. The chemical composition of the materials was determin…
Cultivation of primmorphs from the marine sponge Suberites domuncula: morphogenetic potential of silicon and iron.
2002
Abstract Marine demosponges (phylum Porifera) are rich sources for potent bioactive compounds. With the establishment of the primmorph system from sponges, especially from Suberites domuncula , the technology to cultivate sponge cells in vitro improved considerably. This progress was possible after the elucidation that sponges are provided with characteristic metazoan cell adhesion receptors and extracellular matrix molecules which allow their cells a positioning in a complex organization pattern. This review summarizes recent data on the cultivation of sponges in aquaria and—with main emphasis—of primmorphs in vitro. It is outlined that silicon and Fe(+++) contribute substantially to the f…
Redox tuning and species distribution in Maya Blue-type materials: a reassessment.
2013
Maya Blue-type specimens prepared from indigo (1 wt %) plus kaolinite, montmorillonite, palygorskite, sepiolite, and silicalite are studied. Liquid chromatography with diode array detection, ultra-performance liquid chromatography coupled with mass spectrometry, and pyrolysis-silylation gas chromatography-mass spectrometry analyses of the extracts from these specimens combined with spectral and solid-state voltammetry, electrochemical impedance spectroscopy, and scanning electrochemical microscopy techniques provide evidence for the presence of a significant amount of dehydroindigo and isatin accompanying indigo and other minority organic compounds in all samples. Solid-state electrochemist…
Bioactivity Performance of Pure Mg after Plasma Electrolytic Oxidation in Silicate-Based Solutions
2021
The biodegradable metals, including magnesium (Mg), are a convenient alternative to permanent metals but fast uncontrolled corrosion limited wide clinical application. Formation of a barrier coating on Mg alloys could be a successful strategy for the production of a stable external layer that prevents fast corrosion. Our research was aimed to develop an Mg stable oxide coating using plasma electrolytic oxidation (PEO) in silicate-based solutions. 99.9% pure Mg alloy was anodized in electrolytes contained mixtures of sodium silicate and sodium fluoride, calcium hydroxide and sodium hydroxide. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), contact angle (CA), …
Dental stem cell signaling pathway activation in response to hydraulic calcium silicate-based endodontic cements: A systematic review of in vitro stu…
2020
Abstract Objective To present a qualitative synthesis of in vitro studies which analyzed human dental stem cell (DSC) molecular signaling pathway activation in response to hydraulic calcium silicate-based cements (HCSCs). Methods A systematic electronic search was performed in Medline, Scopus, Embase, Web of Science and SciELO databases on January 20 and last updated on March 20, 2020. In vitro studies assessing the implication of signaling pathways in activity related marker (gene/protein) expression and mineralization induced by HCSCs in contact with human DSCs were included. Results The search identified 277 preliminary results. After discarding duplicates, and screening of titles, abstr…
The cytotoxic evaluation of mineral trioxide aggregate and bioaggregate in the subcutaneous connective tissue of rats
2013
Objectives: The purpose of this study was to evaluate and compare the cytotoxic effects of ProRoot MTA and DiaRoot BA, a bioceramic nanoparticulate cement, on subcutaneous rat tissue. Study D esign: Fifty Sprouge Dawley rats were used in this study. Polyethylene tubes filled with ProRoot MTA and DiaRoot BioAggregate, along with a control group of empty, were implanted into dorsal connective tissue of rats for 7, 15, 30, 60, and 90 days. After estimated time intervals the rats were sacrificed. The specimens were fixed, stained with hematoxylin and eosin, and then evaluated under a light microscope for inflammatory reactions and mineralization. Results: All groups evoked a severe to moderate …
Comparison of two histopathologic methods for evaluating subcutaneous reaction to mineral trioxide aggregate
2011
Objectives: One of the most important factors for suitable materials for pulp therapy is biocompatibility. Two histopathologic methods of Cox and Federation Dentaire International (FDI) were used to evaluate inflammation. In Cox method, density of inflammatory cells, tissue reactions like fibrosis, vascular responses like congestion and fibrin extravasation have been used to evaluate inflammatory reactions. The aim of this study was to compare the accuracy of pathologists’ interpretations using two different methods. Study design: Three pathologists observed the degree of inflammation in 225 histopathologic sections. These sections showed inflammation in subcutaneous connective tissue of ra…