Search results for "Biomaterials"

Haematopoietic stem cell transplantation in the treatment of autoimmune diseases: current experience from an international data base.

2000

Prolonged Response of Chronic Immune Thrombocytopenic Purpura (ITP) to Extracorporeal Immunoadsorption

2000

Muscle-Monitoring Textiles: Cutaneous Recording and Stimulation of Muscles Using Organic Electronic Textiles (Adv. Healthcare Mater. 16/2016)

2016

Theory of mercury intrusion in a distribution of unconnected wedge-shaped slits

2004

Effective mercury intrusion in a wedge-shaped slit is gradual, the intruded depth increasing with applied pressure. The Washburn equation must be modified accordingly. It relates the distance, e, separating the three-phase contact lines on the wedge faces to the hydrostatic pressure, P, wedge half-opening angle alpha, mercury surface tension gamma, and contact angle theta: e=(-2gamma/P)cos(theta-alpha) if theta-alpha>pi2. The equations relating the volume of mercury in a single slit to hydrostatic pressure are established. The total volume of mercury V(Hg)(tot)(E(0),e) intruded in a set of unconnected isomorphous slits (same alpha value) with opening width, E, distributed over interval [E(0…

Intraperitoneal adhesions-an ongoing challenge between biomedical engineering and the life sciences

2011

Peritoneal adhesions remain a relevant clinical problem despite the currently available prophylactic barrier materials. So far, the physical separation of traumatized serosa areas using barriers represents the most important clinical strategy for adhesion prevention. However, the optimal material has not yet been found. Further optimization or pharmacological functionalization of these barriers could give an innovative input for peritoneal adhesion prevention. Therefore, a more complete understanding of pathogenesis is required. On the basis of the pathophysiology of adhesion formation the main barriers currently in clinical practice as well as new innovations are discussed in the present r…

Immediate non-submerged implants with laser-microtextured collar placed in the inter-radicular septum of mandibular molar extraction sockets associat…

2019

Background The aim of the present study was to radiographically evaluate the vertical socket walls changes, and the peri-implant marginal bone remodelling, and clinicallly the soft tissues conditions around the non-submerged single implants placed into the inter radicular septum of mandibular molar sockets, associated with a collagen membrane, after 3 years of loading. Material and Methods Thirty patients underwent to placement of a non-submerged implants with a laser-microtextured collar into the inter radicular septum of mandibular molar fresh extraction sockets. A collagen membrane and the mucoperiosteal flap were adapted around the neck of the implants, leaving the laser-microtextured c…

Toxicity test of a dental commercial composite

2015

BACKGROUND: International rules must be followed for testing biosecurity in dental materials. A new brand of restorative material appeared in the market and regulations indicated that it should be tested for toxicity. OBJECTIVES: The aim of this study was to determine the 90-day sub chronic toxicity of one triethylene glycol dimethacrylate containing composite (MEDENTAL Light-Cure Composite™) orally administered to rats according to Organization for Economic Co-Operation and Development no. 48 guidelines and the requirements specified in the ISO 10993-11. MATERIAL AND METHODS: Wistar rats ate the polymerized composite during 90 days and were observed to determine changes in their behavior, …

Acid—base properties of azo dyes in the presence of surfactants

1991

Abstract The changes in the acid—base properties of an azo dye produced by the presence of surfactants, at surfactant concentrations below and above the CMC, are quantitatively described using a simple model and spectrophotometric and potentiometric measurements. The azo dye formed by aniline and N -(1-naphthyl)-ethylenediamine, and the surfactants sodium dodecyl sulphate, Triton X-100 and N -cetylpyridinium chloride (NCPC) are used. The protonation constants of the free and surfactant-bound dye species, the binding constant of the protonated and unprotonated forms of the dye, and the average aggregation number of the dye—NCPC aggregates are evaluated.

Copolymers sensitive to temperature and pH in water and in water+oil mixtures: A DSC, ITC and volumetric study

2011

Block copolymer micelles are receiving an increasing interest because of the variety of structures and the possibilities to tune them by changing external and internal parameters achieving the desired properties for a specific purpose. We have investigated the acid/base behavior, self-assembling and solubilization ability towards polar oils of star-like copolymers named Tetronics. They are composed of branched four-arms each one consisting of two blocks made of EO and PO units linked to the diethylenediamine group, which confers pH response ability. The copolymers T1107 and T90R4 were studied with a sequential and reverse architecture. The thermodynamics of the acid/base equilibrium was stu…

Transfer of Some Alkyl Substituted Ferrocenes from Water to Cationic Surfactant Micelles Studied by Kinetic Method

1994

Abstract Binding of ferrocene and its 1,1′-dimethyl and n -butyl derivatives to dodecyl and tetradecyltrimethylammonium nitrate micellar aggregates has been studied at 20.0°C and ionic strength 0.02 tool dm -3 by examining the micellar retarding effects on the rates of iron(III) oxidation of these substrates. Solubilization of the ferrocenes in the cationic micellar phase increases as the substrate hydrophobic character increases and, to a lesser extent, as the surfactant hydrocarbon chain length becomes longer. The critical micelle concentrations of the surfactants used and the incremental free energy of transfer of methylene groups of both the substrate and the surfactant from the aqueous…