Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Respiratory mechanics measured by forced oscillations during mechanical ventilation through a tracheal tube
2011
The forced oscillation technique (FOT) allows the measurement of respiratory mechanics in the intensive care setting. The aim of this study was to compare the FOT with a reference method during mechanical ventilation through a tracheal tube. The respiratory impedance spectra were measured by FOT in nine anaesthetized pigs, and resistance and compliance were estimated on the basis of a linear resistance-compliance inertance model. In comparison, resistance and compliance were quantified by the multiple linear regression analysis (LSF) of conventional ventilator waveforms to the equation of motion. The resistance of the sample was found to range from 6 to 21 cmH(2)O s l(-1) and the compliance…
Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites.
2019
Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic sci…
20 years of alveolar distraction : a systematic review of the literature
2018
Background The Vertical Alveolar Distraction Osteogenesis (VADO) technique is an excellent solution for bone and soft tissue neoformation in areas in which there has been significant bone atrophy that hinders normal rehabilitation using dental implants. The goal of this systematic review is to analyze the most relevant articles published on VADO in the literature over the past 20 years. Material and Methods The review was performed by using the keywords: “alveolar ridge”, “distraction ostegenesis” and “dental implant”. This search produced a total result of 240 articles. The clinical studies and cases reported in humans amounted to 113 articles, 18 articles referred to studies developed on …
Non-fragile H ∞ control for switched stochastic delay systems with application to water quality process
2013
SUMMARY In this paper, the problem of non-fragile observer-based H ∞ control for discrete-time switched delay systems is investigated. Both data missing and time delays are taken into account in the links from sensors to observers and from controllers to actuators. Because data missing satisfies the Bernoulli distribution, such problem is transformed into an H ∞ control problem for stochastic switched delay systems. Average dwell time approach is used to obtain sufficient conditions on the solvability of such problems. A numerical example and a real example for water quality control are provided to illustrate the effectiveness and potential applications of the proposed techniques. Copyrig…
Electrosynthesis of Sn-Co nanowires in alumina membranes
2010
A fabrication process of amorphous nanowires of Sn-Co alloys, based on electrodeposition into anodic alumina membranes, is described. It is shown that nanowires of tin-cobalt alloys with different compositions can be produced by varying electrodeposition time and concentration ratio of salts dissolved into the electrolytic bath. Importance of the chelating agent to produce amorphous Sn-Co alloys has also been addressed. Electrodepositions were carried out potentiostatically at -1 V versus Saturated Calomel Electrode and 60 degrees C for times ranging from 10 to 90 minutes; the atomic fraction of Co2+ in the aqueous electrolyte (Co2+/(Co2+ + Sn2+)) was varied from 0.33 to 0.67. Nanowires asp…
Improved section bonding using silanated glass slides--application protocol.
1992
Silanated slides provide excellent tissue adhesion for routine histology, immunohistochemistry and in situ hybridization of frozen, paraffin embedded material or cell smears. An easy and inexpensive method of treating glass microscope slides with triethoxysilylpropylamine is reported.
Signalling molecules and growth factors for tissue engineering of cartilage-what can we learn from the growth plate?
2009
Modern tissue engineering concepts integrate cells, scaffolds, signalling molecules and growth factors. For the purposes of regenerative medicine, fetal development is of great interest because it is widely accepted that regeneration recapitulates in part developmental processes. In tissue engineering of cartilage the growth plate of the long bone represents an interesting, well-organized developmental structure with a spatial distribution of chondrocytes in different proliferation and differentiation stages, embedded in a scaffold of extracellular matrix components. The proliferation and differentiation of these chondrocytes is regulated by various hormonal and paracrine factors. Thus, mem…
Customized Titanium Lattice Structure in Three-Dimensional Alveolar Defect: An Initial Case Letter
2018
The aim of this initial case report was to provide a new protocol for the clinical application of a patient-specific titanium lattice structure (Yxoss CBR®, ReOSS, Filderstadt, Germany) for customized bone regeneration. To obtain a 3-dimensional reconstruction of a posterior mandible segment in a 61-year-old woman, a patient-specific titanium customized lattice structure was used. As graft material autogenous bone tissue mixed with xenogenic alloplastic material (Bio Oss®, Geistlich Pharma, Wolhusen, Switzerland) was obtained for reconstruction. After a healing period of 6 months, the titanium lattice structure was removed and implant placement (Camlog Screw Line, 3.8/11, Camlog, Wimsheim, …
A tooth whitening and chemical abrasive protocol for the treatment of developmental enamel defects
2018
Abstract This clinical report describes a chemical abrasive protocol and whitening techniques to quantify modifications to the color and volume produced when eliminating white spots associated with developmental defects in enamel. Chemical (oxidative-erosive) abrasive treatment (whitening + 6.6% hydrochloric acid) resolves white spots up to a depth of 0.2 mm. At greater depths, infiltration with 16% hydrochloric acid followed by composite resin infiltration is recommended.
The Effect of Calcium on the Cohesive Strength and Flexural Properties of Low-Methoxyl Pectin Biopolymers.
2019
Abstract: Pectin binds the mesothelial glycocalyx of visceral organs, suggesting its potential role as a mesothelial sealant. To assess the mechanical properties of pectin films, we compared pectin films with a less than 50% degree of methyl esterification (low-methoxyl pectin, LMP) to films with greater than 50% methyl esterification (high-methoxyl pectin, HMP). LMP and HMP polymers were prepared by step-wise dissolution and high-shear mixing. Both LMP and HMP films demonstrated a comparable clear appearance. Fracture mechanics demonstrated that the LMP films had a lower burst strength than HMP films at a variety of calcium concentrations and hydration states. The water content also influe…