Search results for "rafting"
showing 10 items of 234 documents
Production of polymeric micro- and nanostructures with tunable properties as pharmaceutical delivery systems
2020
Abstract The production of novel graft copolymers based on poly-e-caprolactone (PCL) and polyaspartamide are useful to realize structures for potential biomedical applications. Here, the synthesis of pegylated PCL/polyhydroxyethyl aspartamide (PHEA) graft copolymers (PHEA-g-SUCC-PCL-g-PEG) with tunable composition, was achieved by followpling a synthetic strategy that involved first the grafting of preformed PCL on PHEA backbone, then polyethylen glycol (PEG), by using 1,1′-carbonyldiimidazole (CDI) to speed up the condensation reaction. Graft copolymers with a Derivatization Degree (DD) in PCL ranging between 1.1 and 4.4 mol% were obtained, and processable with different technologies for t…
Chemical modification of halloysite nanotubes for controlled loading and release.
2020
Clay minerals have been used for medical purposes from ancient times. Among them, the halloysite nanotube, an aluminosilicate of the kaolin group, is an emerging nanomaterial which possesses peculiar chemical characteristics. By means of suitable modifications, such as supramolecular functionalization or covalent modifications, it is possible to obtain novel nanomaterials with tunable properties for several applications. In this context the covalent grafting of suitable organic moieties on the external surface or in the halloysite lumen has been exploited to improve the loading and release of several biologically active molecules. The resulting hybrid nanomaterials have been applied as drug…
Congenital penile curvature: dermal grafting procedure to prevent penile shortening in adults.
2007
Objectives: We report the results of a derma graft corporoplasty in a selected group of patients with congenital penile curvature (CPC) who refused a simple plication technique for the risk of penile shortening, even if minimal. Methods: Between January 1995 and January 2004, 15 potent patients with CPC underwent corporoplasty with inguinal derma graft, with or without tunica albuginea plication. Mean age was 26.6 years (range 1936). Six patients had a simple lateral left curvature, three had a simple lateral right curvature, four had a ventro-lateral left curvature, one patient had a ventro-lateral right curvature, and one patient had ventral curvature. In nine patients the preoperative me…
A job resources-based intervention to boost work engagement and team innovativeness during organizational restructuring
2018
Purpose The purpose of this paper is to investigate the effectiveness of a job resources-based intervention aimed at proactively increasing work engagement and team innovativeness during organizational restructuring using a person-centered approach. Design/methodology/approach The intervention was conducted in two organizations: two departments served as participants (n=82) and two as controls (n=52). The aim was to first identify sub-groups of employees with different developmental patterns of work engagement, and then to determine whether these sub-groups benefited differently from the intervention with respect to team innovativeness and work engagement. Findings Latent profile analysis …
Work engagement-team performance relationship : shared job crafting as a moderator
2016
The aims of this study were twofold: first, to investigate whether both individual and team work engagement are associated with team members' perceived team performance, and, second, to explore whether shared job crafting within teams moderates the relationship between work engagement and team members' perceived team performance. Data were collected from 1,074 Finnish educational sector employees working in 102 teams. Multilevel analysis revealed that both individual and team work engagement were associated with high levels of perceived team performance. The association between work engagement (both individual and team) and perceived team performance, however, varied across teams. The varia…
Corticotomy-assisted orthodontics
2011
The use of orthodontic treatment in adult patients is becoming more common and these patients have different requirements specially regarding duration of treatment and facial and dental aesthetics. Alveolar corticotomy is an effective means of accelerating orthodontic treatment. This literature revision include an historical background, biological and orthodontic fundamentals and the most significant clinical applications of this technique. Orthodontic treatment time is reduced with this technique to one-third of that in conventional orthodontics. Alveolar bone grafting of labial and palatal/lingual surfaces ensures root coverage as the dental arch is expanded. Corticotomy-assisted orthodon…
Immediate Loading in Atrophic Jaws: Zygomatic Implants
2019
The zygomatic fixture is an extended length (35–55 mm) titanium implant, placed into the zygomatic and maxillary alveolar bone. It was designed for situations where atrophy of the posterior maxilla complicates or prevents the placing of conventional implants. The use of zygomatic implants avoids the need for bone grafting, shortens treatment times, and reduces morbidity. They have also been used in patients with maxillectomies resulting from tumors or diseases associated with atrophic conditions of the maxilla.
ALLOGENEIC BONE GRAFTING MATERIALS – UPDATE OF THE CURRENT SCIENTIFIC STATUS
2017
Worldwide population aging and associated with it epidemics of osteoporosis, widespread of bone and joint reconstructive surgery and first of all joint replacement lead to explosive growth of interest in bone grafting.Although autografts are still the golden standard in bone regeneration, allogeneic bone substitutes have reached a state that allows for their application with satisfying clinical results. However, it has repeatedly been supposed that the different allogeneic materials underwent different purification processes, which modifies bone regeneration properties of these materials and also for different safety conditions. In the present publication, the treatment of the precursor tis…
Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide
2012
Free radical grafting of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) porous membranes was studied at 65°C using supercritical carbon dioxide (scCO 2) as a solvent and delivery agent. The process was initiated by the thermal decomposition of benzoylperoxide (BPO). Spectroscopic analyses confirmed the presence of poly(AA) chains linked to treated membranes. The mass fraction of grafted AA increased with grafting time and BPO concentration while it decreased when the density of the fluid phase was enhanced. A not-monotonic trend was obtained when the effect of the initial AA concentration was studied. The grafting process was accompanied by a reduction of the crystallinity of the PVDF…
Modification of EVOH copolymers with e-caprolactone: synthesis and compatibilization effects in PE/PVC blends
2001
Polyethylene-polycaprolactone graft copolymers with different chemical structures (i.e. different number and length of PCL grafts and molecular weight of PE backbone) were synthesized from various EVOH copolymers and e-caprolactone, using Aluminum isopropoxide as catalyst, and were tested for their compatibilizing capability in PE/PVC blends. PE and PCL segments in the graft copolymers were found completely immiscible, while PCL segments of the graft copolymers were found completely miscible with PVC. When graft copolymers were added to PE/PVC blends they proved to be good agents for the dispersion of PVC phase in the PE matrix. SEM showed also improved adhesion between the dispersed PVC ph…