Search results for "plastic"

Salvage therapy with high-dose cytarabine and mitoxantrone in combination with all-trans retinoic acid and gemtuzumab ozogamicin in acute myeloid leu…

2015

Outcome of patients with primary refractory acute myeloid leukemia remains unsatisfactory. We conducted a prospective phase II clinical trial with gemtuzumab ozogamicin (3 mg/m(2) intravenously on day 1), all-trans retinoic acid (45 mg/m(2) orally on days 4-6 and 15 mg/m(2) orally on days 7-28), high-dose cytarabine (3 g/m(2)/12 h intravenously on days 1-3) and mitoxantrone (12 mg/m(2) intravenously on days 2-3) in 93 patients aged 18-60 years refractory to one cycle of induction therapy. Primary end point of the study was response to therapy; secondary end points included evaluation of toxicities, in particular, rate of sinusoidal obstruction syndrome after allogeneic hematopoietic cell tr…

PSA-NCAM is expressed in immature, but not recently generated, neurons in the adult cat cerebral cortex layer II

2011

Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the …

Plasticità e metamorfosi. Riflessioni a partire da Il tempo ritrovato di Marcel Proust

2023

Il racconto della matinée organizzata della principessa Guermantes ne "Il tempo ritrovato", ultimo volume della Ricerca del tempo perduto di Proust, ci consente di confrontarci con ciò che la filosofa francese contemporanea Catherine Malabou definisce il "paradosso dell'invecchiamento". Si tratta di una modalità di metamorfosi che secondo la pensatrice definisce il fenomeno tipicamente umano della plasticità e che ci consente di comprendere l’intimo nesso fra letteratura, filosofia e biologia.

Self-assembled PAA-based nanoparticles as potential gene and protein delivery systems

2012

A series of nanoparticles is prepared via layer-by-layer assembly of oppositely charged, synthetic biocompatible polyamidoamine polymers as potential carriers. Particle size, surface charge and internal chain mobility are quantified as a function of the polymer type and number of layers. The effect of addition of surfactant is examined to simulate the effects of nanoparticle dissolution. The cyctotoxicity of these particles (in epithelia and murine cell lines) are orders of magnitude lower than polyethyleneimine controls. Stable nanoparticles may be prepared from mixtures of strongly, oppositely charged polymers, but less successfully from weakly charged polymers, and, given their acceptabl…

[Appropriate cytotoxic drug usages in solid tumors: conformity to official labelling and level of scientific evidence]

2006

International audience; The definition of appropriate use of drugs is questioned in oncology. Daily therapeutic practices were compared to official labelling and to published scientific data in this retrospective study. It was carried out in two respective specialised centers, from January to September 2004. All chemotherapies administered for adult solid tumours and including one of the eleven studied drugs were evaluated. The analysis of use was performed by drug : conformity to the validated labelling and level of scientific evidence (at the period study). The study included 1,561 drug uses in 1,211 patients. The overall rate of conformity to official labelling was 81.7 % (67.1 % of stri…

Diene/polar monomer copolymers, compatibilisers for polar/non-polar polymer blends. A controlled block copolymerisation with a single-site component …

2002

A well-controlled two-step process, the polymerisation of isoprene or isoprene/hex-1-ene copolymerisation followed by e-caprolactone polymerisation, affords trans-polyisoprene or (trans-polyisoprene/hex-1-ene copolymer)–poly(e-caprolactone) diblocks of various lengths. The single component initiator is an allylsamarocene compound. An atomic force microscopy study shows that these copolymers are efficient compatibilisers for poly(e-caprolactone) and polyisoprene blends. Poly(e-caprolactone) chain growth from Sm–polyisoprene chain.

Synthesis and catalytic properties for olefin polymerization of new vanadium complexes containing silsesquioxane ligands with different denticity

2017

Synthesis and polymerization of active ester monomers based on 4-vinylbenzoic acid

2007

Abstract Nine active ester monomers based on 4-vinylbenzoic acid have been synthesized. Under free radical polymerization conditions these monomers could successfully be polymerized yielding reactive polymers with molecular weights of around M n  = 20.000–50.000 g/mol and molecular weight distributions M w / M n of around or below 2 in good yields. Polymer analogous reactions with amines have been investigated by time-resolved FT-IR spectroscopy and it was found that especially poly(pentafluorophenyl 4-vinylbenzoate) featured a significant reactivity, such that polymer analogous reactions proceeded quantitatively with amines within less than 5 min at 0 °C.

Homogeneous mixtures of polybetaines with low molecular weight salts

1996

The prepaparation of amorphous, homogeneous blends of zwitterionic polymers with various low molecular weight salts, and in particular with ionic dyes was studied. Homogeneous miscibility was achieved in many cases up to equimolar amounts of salt, even for bulky compounds. Whether miscibility is achieved, or not, depends in a subtle way on the chemical structure of the salt, but no obvious correlation between structure and miscibility could yet be revealed. Spectral shifts of the dye UV/Vis spectra in solution as well as in bulk suggest strong interactions between the polybetaines and the admired salts.

Polymer-polymer interaction, in the presence of a solvent as measured by viscometry

2001

Dilute solution viscometry experiments have been carried out in five ternary polymer systems solvent(1)/polymer(2)/polymer(3). Values of the specific viscosity of polymer (3) in a ‘binary solvent’ formed by polymer(2) + solvent(1) have been used to determine the compatibility of the polymer blends. Krigbaum and Wall formalism has been used to predict compatibility which relies on an interaction parameter that depends on the concentration, weight fraction and molar mass of each polymer. To reduce the dependences and to clarify the criterion of compatibility, a parameter independent of polymer (3) composition and molar mass has been deduced. This parameter shows the same behaviour with polyme…