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Water-Dependent Blending of Pectin Films: The Mechanics of Conjoined Biopolymers
2020
Biodegradable pectin polymers have been recommended for a variety of biomedical applications, ranging from the delivery of oral drugs to the repair of injured visceral organs. A promising approach to regulate pectin biostability is the blending of pectin films. To investigate the development of conjoined films, we examined the physical properties of high-methoxyl pectin polymer-polymer (homopolymer) interactions at the adhesive interface. Pectin polymers were tested in glass phase (10&ndash
Effect of Morphology and Size of Halloysite Nanotubes on Functional Pectin Bionanocomposites for Food Packaging Applications
2017
Pectin bionanocomposite films filled with various concentrations of two different types of halloysite nanotubes were prepared and characterized in this study as potential films for food packaging applications. The two types of halloysite nanotubes were long and thin (patch) (200-30 000 nm length) and short and stubby (Matauri Bay) (50-3000 nm length) with different morphological, physical, and dispersibility properties. Both matrix (pectin) and reinforcer (halloysite nanotubes) used in this study are considered as biocompatible, natural, and low-cost materials. Various characterization tests including Fourier transform infrared spectroscopy, field emission scanning electron microscopy, rele…
Peri-implantitis-like medication-related osteonecrosis of the jaw: Clinical considerations and histological evaluation with confocal laser scanning m…
2021
Objective: In the recent years, an increasing number of peri-implant medication-related osteonecrosis of the jaw (PI-MRONJ) have been reported in literature, both in oncologic and osteoporotic patients. The aim of this study is to describe 19 cases of patients previously diagnosed as affected by peri-implantitis, who were treated for PI-MRONJ, with consideration on clinical and histopathological features. Materials and Methods: Patients included were affected by postmenopausal osteoporosis and were administered with different antiresorptive drugs. Due to the presence of clinical and radiological signs of peri-implantitis not healed after non-surgical periodontal treatment, they were referre…
The structure and phase transition of tris(n-propylammonium) enneachlorodiantimonate (III),
1996
The crystal structure of at 298 K has been determined (monoclinic, space group Cc, a = 19.464(2) ?, b = 17.736(2) ?, c = 8.116(2) ?, , Z = 4). The structure consists of one-dimensional polyanionic chains extended along the c-axis, and n-propylammonium cations located in elongated cavities formed by polyanions. The cations are connected to chlorine atoms by hydrogen bonds. Differential scanning calorimetry, the temperature dependence of the lattice parameters and static electric permittivity studies revealed a first-order phase transition at K of an `order - disorder' type. It is related to the ordering of n-propylammonium cations that occurs on decreasing the temperature. Debye-like dispers…
The Structural and Dielectric Properties of the Li0.005Na0.995NbO3Ceramics
2009
The sodium niobate-lithium niobate (Li x Na1 − x NbO3) compounds were synthesized using conventional solid-state processing. Phase analysis was performed by X-Ray diffraction, and microstructural morphology was assessed by scanning electron microscopy. The dielectric measurements were performed in heating and cooling processes without and under axial pressure up to 120 MPa. It has been stated, that the maximum of electric permittivity ϵ (T) becomes more diffused with the increase of axial pressure and the temperature of phase transition T0 decreases. The value of tanδ increases with the increase of axial pressure and its local maximum shifts towards lower temperatures.
Germanium modified BaTiO3as a promising electroceramics
2016
ABSTRACTThe polycrystalline sample of BaTi0.95Ge0.05O3 was prepared by solid-phase reaction using a conventional method. The morphology of investigated sample was characterised by scanning electron microscopy (SEM). The results allowed to determining the stoichiometry of the material and evaluate their microstructure. High quality samples were investigated, the grains are well shaped without of a glassy phase. The dielectric properties of the BaTi0.95Ge0.05O3 ceramics were determined. The results were compared with these ones obtained for pure BaTiO3. The obtained data indicated that the substitution of Ge+4 ions had an influence on the values of the real (ϵ′) and imaginary (ϵ″) parts of el…
Crystal growth and hysteresis phenomena of rubidium tetrachlorozincate Rb2ZnCl4
1988
Abstract Phase transitions in Rb2ZnCl4 crystals grown by various methods are examined with differential scanning calorimetry and dielectric measurements. For most of the studied samples the permittivity along the ferroelectric axis shows a large thermal hysteresis over a wide temperature range including the incommensurate phase and the lock-in point. This hysteresis depends on the presence of different defects which appear during crystal growth or after a thermal and mechanical treatment. It is shown that dielectric measurements are quite well suited to characterize the crystals exhibiting on incommensurate phase and a ferroelectric phase.
Structural characterization, thermal, dielectric, vibrational properties and molecular dynamics of (C5H5NH)3BiCl6
2009
Abstract (C5H5NH)3BiCl6 crystallizes at room temperature in the triclinic space group P 1 ¯ . The crystal is built up of the separated BiCl 6 3 - octahedral anions and pyridinium cations. Differential scanning calorimetry (DSC) and dilatometric measurements disclose structural phase transition of first-order type at 265/302 K (cooling/heating). The dielectric investigations reveal a step-wise change of the electric permittivity at Tc characteristic of the crystals with the high-temperature plastic-like phase. Temperature-dependent infrared spectra for polycrystalline samples have been taken between 20 and 306 K to clarify the cation dynamics contribution to the mechanism of the phase transi…
Influence of poloxamers on the dissolution performance and stability of controlled-release formulations containing Precirol® ATO 5
2005
Abstract Lipid excipients are usually used for the development of sustained-release formulations. When used in relatively high quantities, Precirol ® ATO 5 imparts sustained-release properties to solid oral dosage forms, by forming a lipid matrix. To control or adjust the drug release kinetics from such lipid matrix however, one must often resort to complementary ingredients or techniques. This study investigates the influence of poloxamers (Lutrol ® ) included in lipid matrices composed of glyceryl palmitostearate (Precirol ® ATO 5) on their dissolution performance and their stability. The addition of these hydrophilic polymers in the lipid matrix increased the amount of theophylline relea…
Application of Organic Monolithic Materials to Enantioseparation in Capillary Separation Techniques.
2017
This review article is primarily focused on the state-of-the-art of enantioseparations on organic monolithic materials. The article gives an overview of the chiral stationary phases and its application in capillary electrochromatography (CEC), and capillary- and nano-liquid chromatography (cLC and nLC). Since thousands of publications have been emerged from 2000’s and citing all these papers would extend the scope of this review; then, recent developments from last 10 years (2006 to 2016) will be mentioned. Mostly, stationary phases based on copolymers obtained from chiral functional monomers and surface modifications of organic monoliths with chiral ligands will be discussed. The effective…