Search results for "d-a"
showing 10 items of 426 documents
PHEA-graft-polybutylmethacrylate copolymer microparticles for delivery of hydrophobic drugs.
2012
Abstract Polymeric microparticles encapsulating two model hydrophobic drugs, beclomethasone dipropionate (BDP) and flutamide (FLU) were prepared by using the high pressure homogenization-solvent evaporation method starting from a oil-in-water emulsion. For the preparation of polymeric microparticles a α,β-poly(N-2-hydroxyethyl)- d , l -aspartamide (PHEA) graft copolymer with comb like structure was properly synthesized via grafting from atom transfer radical polymerization (ATRP) technique, by using two subsequent synthetic steps. In the first step a polymeric multifunctional macroinitiator was obtained by the conjugation of a proper number of 2-bromoisobutyryl bromide (BIB) residues to the…
Side-specific effects by cadmium exposure: Apical and basolateral treatment in a coculture model of the blood–air barrier
2010
Cadmium (Cd{sup 2+}) is a widespread environmental pollutant, which is associated with a wide variety of cytotoxic and metabolic effects. Recent studies showed that intoxication with the heavy metal most importantly targets the integrity of the epithelial barrier. In our study, the lung epithelial cell line, NCI H441, was cultured with the endothelial cell line, ISO-HAS-1, as a bilayer on a 24-well HTS-Transwell (registered) filter plate. This coculture model was exposed to various concentrations of CdCl{sub 2}. The transepithelial electrical resistance decreased on the apical side only after treatment with high Cd{sup 2+} concentrations after 48 h. By contrast, a breakdown of TER to less t…
SYNTHESIS, CHARACTERIZATION AND IN VITRO CYTOTOXICITY STUDIES OF A MACROMOLECULAR CONJUGATE OF PACLITAXEL BEARING OXYTOCIN AS TARGETING MOIETY.
2007
The present study describes the experimental synthetic procedure and the characterization of a new polyaspartamide macromolecular prodrug of paclitaxel, bearing oxytocin residues as targeting moieties. In vitro stability studies of bioconjugate, performed in media mimicking biological fluids (buffer solutions at pH 7.4 and 5.5) and in human plasma, evidenced the high stability of the targeting portion (oxytocin)-polymer linkage and the ability of this conjugate to release linked paclitaxel in a prolonged way in plasma. Moreover, preliminary in vitro antiproliferative studies, carried out on MCF-7 cells, that are oxytocin receptor positive cells, showed that the polymeric conjugate has the s…
Effects of propanil on the European eel Anguilla anguilla and post-exposure recovery using selected biomarkers as effect criteria
2008
Abstract The aim of this study was to assess the physiological response of Anguilla anguilla to propanil and the degree of recovery after being moved to clean water. Preliminary acute toxicity test was carried out in the laboratory and the median lethal concentration (LC50) at 96 h was calculated as 31.33 mg/L (29.60–33.59 mg/L). NOEC and LOEC values (at 96 h) were also calculated as 20 and 25 mg/L, respectively. The fish were exposed to 0.63 and 3.16 mg/L of propanil for 72 h and allowed to recover for 144 h. Total proteins (TPs), γ -glutamil transpeptidase ( γ -GT), alanin aminotransferase (AlAT), alkaline phosphatase (AP), lactate dehydrogenase (LDH) and water content (WC) were assayed i…
Prostaglandin E(2)-loaded microspheres as strategy to inhibit phagocytosis and modulate inflammatory mediators release.
2008
PGE(2), an arachidonic acid metabolite produced by various type of cells regulates a broad range of physiological activities in the endocrine, cardiovascular, gastrointestinal, and immune systems, and is involved in maintaining the local homeostasis. In the immune system, PGE(2) is mainly produced by APCs and it can suppress the Th1-mediated immune responses. The aim of this study was to develop PGE(2)-loaded biodegradable MS that prolong and sustain the in vivo release of this mediator. An o/w emulsion solvent extraction-evaporation method was chosen to prepare the MS. We determined their diameters, evaluated the in vitro release of PGE(2), using enzyme immunoassay and MS uptake by periton…
Nano into Micro Formulations of Tobramycin for the Treatment of Pseudomonas aeruginosa Infections in Cystic Fibrosis.
2017
Here, nano into micro formulations (NiMs) of tobramycin for the treatment of Pseudomonas aeruginosa airway infections in cystic fibrosis (CF) are described. NiMs were produced by spray drying a solution containing polymers or sugars and a nanometric polyanion–tobramcyin complex (PTC), able to achieve a prolonged antibiotic release. NiMs properties were compared to TOBIPodhaler(Novartis), the only one commercially available dry powder inhalatory formulation based on porous microparticles. Produced NiMs showed adequate characteristics for pulmonary administration, as spherical shape, micrometric size, and high cytocompatibility toward human bronchial epithelial cells. Contrarily to TOBIPodhal…
Multi-mycotoxin determination in barley and derived products from Tunisia and estimation of their dietary intake.
2017
A study on raw barley and derived products (barley soup and beers) was carried out to determine the natural presence of twenty-four mycotoxins by both liquid chromatography and gas chromatography coupled to tandem mass spectrometry (MS/MS). The developed multi-mycotoxin procedure was based on both SLE and QuEChERS extraction steps. 66% of analyzed samples presented mycotoxin contamination and only one sample, which was soup of barley (6 ng/g), exceeded the maximum level (ML) established by EU for OTA (5 ng/g). Raw barley was the most contaminated matrix (62%), which concentrations ranged from 1.70 to 287.13 ng/g) and type of detected mycotoxins (DON, 15AcDON, NEO, NIV, HT2, FB1, OTA, ENA, E…
Badania archeologiczne na Ukrainie nad Dunajem w miejscowości Kartal/Orłowka
2020
Głównym celem artykułu jest przedstawienie badań archeologicznych z 2013 r. w miejscowości Kartal/Orłowka na Ukrainie. Badania dotyczyły odkrycia wielokulturowego kompleksu osadniczego i znajdującego się na nim cmentarzyska. Odkryte cmentarzysko związane jest z eneolitem i epoką brązu. Pochówki szkieletowe odkryte podczas wykopalisk ułożone były w pozycji embrionalnej (skurczone po prawej stronie, nogi podciągnięte pod klatkę piersiową), jeden z nich był podwójny. Przy pochówkach odnaleziono wyposażenie w postaci miski ceramicznej i małego glinianego naczynia. Kości ludzkie zachowane były w złym stanie, zostały uszkodzone przez czas, glebę i niewielką głębokość zalegania pochówku. Badacze r…
Weak chord-arc curves and double-dome quasisymmetric spheres
2014
Let $\Omega$ be a planar Jordan domain and $\alpha>0$. We consider double-dome-like surfaces $\Sigma(\Omega,t^{\alpha})$ over $\overline{\Omega}$ where the height of the surface over any point $x\in\overline{\Omega}$ equals $\text{dist}(x,\partial\Omega)^{\alpha}$. We identify the necessary and sufficient conditions in terms of $\Omega$ and $\alpha$ so that these surfaces are quasisymmetric to $\mathbb{S}^2$ and we show that $\Sigma(\Omega,t^{\alpha})$ is quasisymmetric to the unit sphere $\mathbb{S}^2$ if and only if it is linearly locally connected and Ahlfors $2$-regular.
La atención a la situación del mundo en la educación científica
2021
Protagonizamos en la actualidad una epoca de profundas y aceleradas transformaciones que, unida a una multiplicidad de problemas medioambientales y sociales cuyos efectos vienen agravandose a nivel planetario, ha convertido la "situacion del mundo" en objeto directo de preocupacion. En la Conferencia de las Naciones Unidas sobre Medio Ambiente y Desarrollo, celebrada en Rio de Janeiro en 1992 y conocida como Primera Cumbre de la Tierra, se reclamo una decidida accion de los educadores, de todas las areas, para que los ciudadanos y ciudadanas adquieran una correcta percepcion de cual es esa situacion y puedan participar en la toma de decisiones fundamentadas. Un primer proposito de esta inve…