Search results for "GRAFTING"

Development of polymer-based nanoparticles for Zileuton delivery to the lung : PMeOx and PMeOzi surface chemistry reduces interactions with mucins

2021

In this paper, two amphiphilic graft copolymers were synthesized by grafting polylactic acid (PLA) as hydrophobic chain and poly(2-methyl-2-oxazoline) (PMeOx) or poly(2-methyl-2-oxazine) (PMeOzi) as hydrophilic chain, respectively, to a backbone of α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). These original graft copolymers were used to prepare nanoparticles delivering Zileuton in inhalation therapy. Among various tested methods, direct nanoprecipitation proved to be the best technique to prepare nanoparticles with the smallest dimensions, the narrowest dimensional distribution and a spherical shape. To overcome the size limitations for administration by inhalation, the nano-into-micr…

SURFACE MODIFICATION OF EAA WITH FUNCTIONALIZED SILICA NANOPARTICLES

2009

Utilization of Poly(vinylchloride) and Poly(vinylidenefluoride) as Macroinitiators for ATRP Polymerization of Hydroxyethylmethacrylate. Electroanalyt…

2015

The utilization of poly(vinylchloride) (PVC) and poly(vinylidenefluoride) (PVDF) as macroinitiators for atom transfer radical polymerization (ATRP) of hydroxyethylmethacrylate (HEMA) was studied performing electroanalytical investigations and “grafting from” experiments in order to achieve information on the possibility of modifying such commercial polymers by this controlled free radical polymerization technique. This study was performed changing various operating parameters such as the nature of the copper salt, the ligand, the solvent, the temperature and the reaction time. Electroanalytical data suggest that PVC can be easily activated by both CuCl/ Tris(2-pyridylmethyl)amine (TPMA) and…

When Functionalization of PLA Surfaces Meets Thiol−Yne Photochemistry: Case Study with Antibacterial PolyaspartamideDerivatives

2014

International audience; In this work we wish to report on the covalent functionalization of polylactide (PLA) surfaces by photoradical thiol–yne to yield antibacterial surfaces. At first, hydrophilic and hydrophobic thiol fluorescent probes are synthesized and used to study and optimize the conditions of ligation on alkyne-PLA surfaces. In a second part, a new antibacterial polyaspartamide copolymer is covalently grafted. The covalent surface modification and the density of surface functionalization are evaluated by SEC and XPS analyses. No degradation of PLA chains is observed, whereas covalent grafting is confirmed by the presence of S2p and N1s signals. Antiadherence and antibiofilm acti…

Marginal bone loss around cement and screw-retained fixed implant prosthesis

2018

Background Implant-supported fixed restorations are considered as the standard treatment for replacement of missing teeth. These can be either screw or cement retained. The success or failure of implant restorations depend upon amount of marginal bone loss (MBL). The present study is to determine the MBL around cement and screw-retained implant prosthesis and to determine various predictors of the MBL. Material and Methods A retrospective charts review was conducted at the dental clinics, Aga Khan University Hospital, Karachi from February 2017 to June 2017 in which 104 implants restorations were assessed using periapical radiographs. MBL was calculated at baseline and at 12 months and the …

Unravelling Radicals Reactivity Towards Carbon Nanotubes Manipulation/Functionalization

2016

Carbon Nanotubes (CNTs) chemistry is under constant evolution, as a consequence of the deep interest of the scientific community in finding new applications for these versatile materials. New and old synthetic protocols are used for improving the control of the functionalization degree of the final materials and for offering to scientists the possibility to fine-tune their final properties. In this Review, we focus the attention on radical reactions, a class of protocols characterized by small number of steps, different degrees of functionalization and enhanced solubility of the final modified CNTs, in the desired environment. The most well-known protocols are analysed providing some releva…

One-year implant survival following lateral window sinus augmentation using plasma rich in growth factors (PRGF) : a retrospective study

2019

Background The aim of this study was to assess one-year implant survival after lateral window sinus augmentation using PRGF combined with various bone grafting materials. Material and Methods This was a retrospective chart review and radiographic analysis of patients that had undergone lateral window sinus augmentation with PRGF and had dental implants placed at least 6 months post augmentation. All implants included were followed up for at least one year after placement. Demographic, sinus and implant related characteristics (residual ridge height, sinus membrane perforation, type of graft material, implant length and width and ISQ at placement) were analyzed. Results A total of 31 patient…

Grafting, self-organization and reactivity of double-decker rare-earth phthalocyanine

2019

Unveiling the interplay of semiconducting organic molecules with their environment, such as inorganic materials or atmospheric gas, is the first step to designing hybrid devices with tailored optical, electronic or magnetic properties. The present article focuses on a double-decker lutetium phthalocyanine known as an intrinsic semiconducting molecule, holding a Lu ion in its center, sandwiched between two phthalocyanine rings. Carrying out experimental investigations by means of electron spectroscopies, X-ray diffraction and scanning probe microscopies together with advanced ab initio computations, allows us to unveil how this molecule interacts with weakly or highly reactive surfaces. Our…

Hydraulic kinetics of the graft union in different Olea europaea L. scion/rootstock combinations

2007

The hydraulic resistance of young olive trees grafted on rootstocks with contrasting size-controlling potential was measured 30, 90, 360 and 480 days after grafting. Olive (Olea europaea L.) clones inducing plant vigorous growth (Leccino ‘Minerva’, LM) or dwarfing (Leccino ‘Dwarf’, LD) were studied in different scion/rootstock combinations (LD/LD, LD/LM, LM/LD, LM/LM). Plants growing on LD root systems developed lower leaf surface areas (about 50% less) than plants grafted on LM rootstocks. Graft union represented the largest fraction (up to 85%) of whole-plant hydraulic resistance 30 days after grafting, and still represented an important fraction of it 2 months later (40–55%). Four-hundre…

Kairomone involvement in the host specificity of the egg parasitoid Trissolcus basalis

2006

This paper reports the results of a comparative laboratory analysis of the behavioural responses of the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae) to semiochemical cues from four species of pentatomid bugs, Nezara viridula (L.), Eurydema ventrale Klt., Murgantia histrionica Hahn. and Graphosoma semipunctatum F. (Heteroptera: Pentatomidae). In a Y-tube olfactometer, T. basalis was attracted by volatile chemicals from N. viridula, but not from other pentatomid species. In an open arena, the parasitoid reacted to chemical trails left on filter paper by all the species but most intensely to those left by N. viridula. However, upon encountering pentatomid eggs, T. b…