Search results for "polymer"
showing 10 items of 10504 documents
Direct asymmetric aldol reaction using polystyrene-supported proline amide
2008
NOVEL PAHY-GRAFT COPOLYMERS AS MICELLAR DRUG CARRIER FOR ANTICANCER DRUGS
2009
DES-polyacetals as polymer therapeutics for the treatment of prostate cancer
2012
Esta tesis se centra en el diseño de nuevos conjugados polímero-fármaco sensibles a pH para usarse como agentes únicos o en terapia de combinación para el tratamiento del cáncer hormono-dependiente, en particular cáncer de próstata. Éstos conjugados se basan en sístemas poliacetalicos previamente descritos en los que el fármaco forma parte de la cadena principal del polímero. En el microambiente tumoral o después de la absorción celular por endocitosis, el descenso del pH encontrado en el compartimiento ácido del endosoma lisosomal, desencadena la degradación del polímero y como consecuencia la liberación del fármaco que se difunde fuera en el citosol. Para el diseño de éstos sistemas, la n…
Recycling ground tire rubber (GTR) scraps as high-impact filler of in-situ produced polyketone matrix
2014
Determinación de Streptococcus Mutans y Streptococcus Sobrinus, mediante pcr cuantitativa a tiempo real, y su relación con la caries dental en escola…
2013
La caries dental presenta una etiología multifactorial, los factores ambientales, los hábitos de alimentación, higiene bucal y la susceptibilidad genética individual, juegan un papel importante en el desarrollo de esta enfermedad (1). Los Streptococcus mutans y Streptococcus sobrinus están fuertemente implicados en la aparición de la caries dental en humanos. Numerosos estudios han demostrado que la asociación de S. mutans y S. sobrinus conlleva niveles más altos de caries (2-4) y varios estudios han encontrado que la prevalencia deS. sobrinus está fuertemente asociada con mayor actividad de caries que la delS. mutans (5-6). Se considera que la determinación de estas dos especies en la infa…
Soybean Diseases Caused by Genus Pseudomonas Phytopathenes Bacteria
2019
The rationale and experimental confirmation of the role of the bacteria of the Pseudomonas genus in the pathogenesis of soybean, and the investigation of the biological properties of the main causative agent Pseudomonas savastanoi pv. glycines. Methods. Theoretical generalization, laboratory-model research, phytopathological, microbiological, physiological, biochemical and genetic methods. Results. The largest group of pathogens in different soil-climatic zones of Ukraine consists of bacteria of the genus Pseudomonas was established. Their biological properties have been investigated and the methods for identification of the dominant type of phytopathogenic bacteria causing bacterial blight…
Block copolymers from ionic liquids for the preparation of thin carbonaceous shells
2017
This paper describes the controlled radical polymerization of an ionic-liquid monomer by RAFT polymerization. This allows the control over the molecular weight of ionic liquid blocks in the range of 8000 and 22000 and of the block-copolymer synthesis. In this work we focus on block copolymers with an anchor block. They can be used to control the formation of TiO2 nanoparticles, which are functionalized thereafter with a block of ionic-liquid polymer. Pyrolysis of these polymer functionalized inorganic nanoparticles leads to TiO2 nanoparticles coated with a thin carbonaceous shell. Such materials may, e.g., be interesting as battery materials.
HYALURONIC ACID BASED-MICELLES FOR OFF-LABEL USE OF IMATINIB IN RETINOPATHIES TREATMENT
2018
The aim of this work was to obtain polymeric micelles able to cross corneal barrier and to improve the permeation of imatinib free base. Micelles were prepared by using hyaluronic acid (HA) derivatives containing ethylenediamine (EDA), chains of hexadecyl (C16), polyethylene glycol (PEG) and/or L-carnitine (CRN). The resulting samples, named as HA-EDA-C16, HA-EDA-C16-PEG and HA-EDA-C16-CRN micelles, were designed to allow a non-invasive way of administration, i.e. topical ocular instillation. These nanocarriers showed an optimal particle size in aqueous media and mucoadhesive properties. Imatinib-loaded micelles were able to interact with corneal barrier and to promote imatinib transcorneal…
Realization of polyaspartamide-based nanoparticles and in vivo lung biodistribution evaluation of a loaded gucocorticoid after aerosolization in mice
2016
Abstract In this study, novel polymeric nanoparticles (NPs) were developed and their potential as carriers for beclomethasone dipropionate (BDP) into the lung after aerosolization was demonstrated by in vivo studies in mice. In particular, these NPs were obtained starting from two polyaspartamide-based copolymers which were synthesized by chemical reaction of α,β-poly(N-2-hydroxyethyl)- dl -aspartamide (PHEA) and its pegylated derivative (PHEA-PEG2000) with poly(lactic acid) (PLA). To obtain nanosized particles, the high pressure homogenization (HPH)—solvent evaporation method was followed by using an organic phase containing both PHEA-PLA and PHEA-PEG2000-PLA (at a weight ratio equal to 1:…
Effect of hydrogen on the ethylene polymerization process over Ziegler–Natta catalysts supported on MgCl2(THF)2. II. Kinetic studies
2001
This article reports on a study of the effects of hydrogen on the activity of vanadium and titanium catalysts supported on MgCl2(THF)2 in ethylene polymerization. It was found that hydrogen did not change the stable nature of the active sites and the polydispersity index of the polyethylene obtained. The propagation rate, expressed as kp, was found to be independent of the presence and concentration of hydrogen, indicating that this reacting agent does not modify the reactivity of the active sites. However, the presence of hydrogen in the polymerization medium is responsible for partial deactivation of the active sites just before polymerization is initiated.