Search results for "020601 biomedical engineering"
showing 10 items of 335 documents
The effects of shock wave stimulation of mesenchymal stem cells on proliferation, migration, and differentiation in an injectable gelatin matrix for …
2020
The treatment of a variety of defects in bony sites could benefit from mitogenic stimulation of osteoprogenitor cells, including endogenous bone marrow-derived mesenchymal stem cells (bMSCs), and from provision of such cells with a matrix permissive of their migration, proliferation, and osteogenic differentiation. That such MSC stimulation could result from treatment with noninvasive (extracorporeal) shock waves (ESWs), and the matrix delivered by injection could enable this therapeutic approach to be employed for applications in which preformed scaffolds and growth factor therapy are difficult to deploy. The objectives of the present study were to investigate focused ESWs for their effect…
Hydration Chemistry of Cement Studied by Near Infrared Spectroscopy
2018
Cement is a complex mixture of inorganic compounds which mainly composed of calcium silicates and calcium aluminates. Cement is mixed with water to form concrete. During the mixing calcium silicate hydrate (CSH) and calcium hydroxide are formed. The ratio of water/cement (w/c ratio) is important to obtain a mixture that gives optimum strength to the concrete. In this work, three different cement samples were mixed with water in four different ratios, including 0.35, 0.40, 0.45 and 0.55, respectively. The hydration process of cement was investigated by using near infrared (NIR) spectroscopy over a period of 28 days. The combination frequency of OH stretching and bending of water molecules gi…
Influence of thickness and translucency of lithium disilicate ceramic on degree of conversion of resinous materials
2020
Background In this study was assessed the degree of conversion (DC) of amine-free resin cements light cured through lithium disilicate-reinforced ceramics at different thicknesses and translucency. Material and Methods Specimens were divided into 21 groups (n = 5) according to luting agent used: Variolink Esthetic LC (Light shade), RelyX Ultimate (A1 shade), and Filtek Z350 XT Flow (A1 shade); the ceramic translucency: low (LT) and high (HT); and the ceramic thickness: no ceramic (control), 0.5 mm, 1 mm, and 2 mm. A Teflon mold with (5 x 5 x 0.5 mm) was used to standardize the cement and over it the ceramic block from each group was placed. Set was cured using a polywave LED light (1200 mW/…
Root canal adaptation and intra-tubular penetration of three fiber-post cementation systems
2018
Background To measure the penetration of three bonding systems for the luting of fiber glass posts in endodontically treated teeth, using confocal laser scanning microscopy (CLSM). Material and Methods A total of 30 maxillary incisors were shaped with the Mtwo system and filled with gutta-percha and Top Seal cement. The sample was divided into three groups (ni=10) according to the bonding system used to cement the posts: Group 1 (Prime&Bond NT and Rebilda DC with a total-etch technique); Group 2 (Futurabond DC and Rebilda DC with a dentin self-etch technique); and Group 3 (BisCem self-adhesive cement). Rhodamine B was added to the bonding systems to allow visualization by CLSM. Three 1-mm t…
Influence of resin cement shade on the color and translucency of zirconia crowns
2020
Background Zirconia crowns are highly attractive for clinicians, although have poor translucency when used as single restorations, in addition to unknown effect of resin cement shade on final cemented crown shade. This study aimed to assess effect of resin cement opacity on color replication potential of different zirconia frameworks with target tooth color, in addition to different zirconia crowns translucency evaluation. Material and methods Twenty-four zirconia crown restorations were fabricated to restore single central maxillary incisor for 8 patients, divided into 3 groups according to color and type of zirconia used (white Zr core, colored Zr core and monolithic HT Zrcowns). Each gro…
Bond strength according to the moment of fiber post cutting fixed with self-adhesive cement to the root dentin
2021
Background The fiber posts require a cut in the coronal portion to adjust it to the available clinical space. The cutting of posts cemented may generate tension via bur vibrations of drill on the bonding interface, with the possibility of decreasing the bond strength. Thus, this study aimed to evaluate if the moment of cutting the fiber posts has an effect on its bond strength when fixed with self-adhesive resin cement. Material and methods Thirty-six bovine teeth were randomly divided into three groups after endodontic treatment and post space preparation (n = 12): IAC- the fiber posts were cutting immediately after cementation; ACR - the fiber posts were cutting after coronal reconstructi…
Influence of the chemical composition of monolithic zirconia on its optical and mechanical properties. Systematic review and meta-regression.
2021
Este artículo se encuentra disponible en la siguiente URL: https://www.jstage.jst.go.jp/article/jpr/66/2/66_JPR_D_20_00218/_pdf/-char/en Este artículo de investigación pertenece al número especial "Advances in Personalized Nursing Care". Purpose: This systematic review set out to investigate the influence of chemical composition and specimen thickness of monolithic zirconia on its optical and mechanical properties. Meta-analysis and meta-regression analyzed the effects of variations in percentages of yttrium, aluminum, and specimen thickness of monolithic zirconia. Study selection: The review followed recommendations put forward in the PRISMA checklist. An electronic search for relevant art…
Kinetics of rat CSD-C2 binding to H3.3 RNA
2017
Cold-shock domain containing protein C2 (CSD-C2; also known as PIPPin) is an RNA-binding protein conserved in the evolution that interacts with the 3’-untranslated region (3’-UTR) of rat H1.0 and H3.3 histone messengers. Biolayer interferometry (BLI) is a technique that measures changes in an interference pattern generated from visible light, reflected from an optical layer, and a biolayer which contains molecules of interest. In this study, we used the BLI methodology in order to analyze and describe the binding properties of CSD-C2 and the mRNA encoding the rat brain histone protein H3.3. Recombinant CSD-C2 was incubated with in vitro transcribed, and biotinylated H3.3 RNA fragments bound…
End-user Need based Creation of a Medical Device: An Experience of Co-design to Struggle Pathological Scars
2020
International audience; Scar is a common visible mark of human tissue healing. Sometimes pathological phenomena lead to abnormal hypertrophic or keloid scars, with evolutions varying depending on different conditions: origin of the tissue barrier disruption, concerned body area, or ethnic origin. Based on these statements, care procedures have been developed to avoid aesthetical or functional impairments: drugs injection, surgery, cryotherapy or mechanical compression. The story will relate the matching of a multi-disciplinary team that focused on covering an unmet need for ear lobe keloid treatment, providing patients an optimal and holistic care. The benefits researched lied in improving …
Automatic estimation of Purkinje-Myocardial junction hot-spots from noisy endocardial samples: A simulation study
2017
The reconstruction of the ventricular cardiac conduction system (CCS) from patient-specific data is a challenging problem. High-resolution imaging techniques have allowed only the segmentation of proximal sections of the CCS from images acquired ex vivo. In this paper, we present an algorithm to estimate the location of a set of Purkinje-myocardial junctions (PMJs) from electro-anatomical maps, as those acquired during radio-frequency ablation procedures. The method requires a mesh representing the myocardium with local activation time measurements on a subset of nodes. We calculate the backwards propagation of the electrical signal from the measurement points to all the points in the mesh …