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A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide
2009
The surfactant assisted polymerization of 1-vinyl-2-pyrrolidone in supercritical carbon dioxide in the presence of Piroxicam, selected as a model of a low aqueous solubility drug, was studied in order to prepare in a single step a polymeric composite to enhance the rate of dissolution of the pharmaceutical compound. Reactive entrapping was carried out at 65 degrees C in the P range 21-38MPa. Under proper operative conditions we obtained the composite under the form of sub-micron spherical particles with relatively narrow particle size distribution. Drug loadings higher than 12% (w/w) were obtained and XRD and Raman spectroscopy suggest that the anti-inflammatory agent is dispersed in the ma…
Amorphous and crystalline polyetheretherketone: Mechanical properties and tissue reactions during a 3-year follow-up.
2007
The study was aimed to test the mechanical strength, structural stability, and tissue reactions of optically amorphous and crystalline polyetheretherketone (PEEK) plates during a 3-year follow-up in vivo and in vitro. The injection-moulded PEEK plates were implanted to the dorsal subcutis of 12 sheep, which were sacrificed at 6-156 weeks. Thereafter, the plates were subjected to tensile tests, and levels of crystallinity were assessed by differential scanning calorimetry (DSC). Histological evaluation was carried out using the paraffin technique. In vitro properties were examined with the tensile test and DSC at 0-156 weeks. Tissue reactions were mild and fairly similar for the amorphous an…
Dependence of the Optical Constant Parameters of p-Toluene Sulfonic Acid-Doped Polyaniline and Its Composites on Dispersion Solvents
2020
The optical constants of Para-Toluene sulfonic acid-doped polyaniline (PANI), PANIchitosan composites, PANI-reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide dispersed in diluted p-toluene sulfonic acid (PTSA) solution and N-Methyl-2-Pyrrolidone (NMP) solvent have been evaluated and compared. The optical constant values were extracted from the absorbance spectra of thin layers of the respective samples. The potential utilization of the materials as the active sensing materials of surface plasmon resonance biosensors has also been assessed in terms of the estimated value of the penetration depth through a dielectric medium. The …
Sobre grupos radicales localmente finitos con min-p para todo primo p.
2003
SUMARY A group is said to be locally finite if every finite subset of G generates a fi-nite subgroup. The class of locally finite groups is placednear the cross-roads of finite group theory and the general theory of infinite groups. Many theorems about finite groups can be phrased in such a way that their statements still make sense for locally finite groups. However, in general, Sylows Theorems do not hold in the class of locally finite groups and there are a number of generic examples which show that locally finite groups can be very varied and complex. If we restrict our attention to locally finite-soluble groups with min-p for all primes p then the Sylow ¼-subgroups are very well behave…
Milrinone is preferred to levosimendan for mesenteric perfusion in hypoxia-reoxygenated newborn piglets treated with dopamine
2012
INTRODUCTION There is little information regarding the comparative hemodynamic effects of adding milrinone or levosimendan to dopamine infusion in hypoxia-reoxygenated (H-R) newborns. RESULTS Severely hypoxic piglets had cardiogenic shock with depressed cardiac index (CI) and mean arterial pressure (MAP). The hemodynamics deteriorated gradually after initial recovery upon reoxygenation. Heart rate and CI improved with milrinone (D+M) and levosimendan (D+L) administration (P < 0.05 vs. control). Both regimens improved carotid arterial flow and carotid vascular resistance; D+M additionally improved superior mesentric arterial flow (all P < 0.05 vs. control). No effect was found on renal arter…
Landomycins as glutathione-depleting agents and natural fluorescent probes for cellular Michael adduct-dependent quinone metabolism
2021
Landomycins are angucyclines with promising antineoplastic activity produced by Streptomyces bacteria. The aglycone landomycinone is the distinctive core, while the oligosaccharide chain differs within derivatives. Herein, we report that landomycins spontaneously form Michael adducts with biothiols, including reduced cysteine and glutathione, both cell-free or intracellularly involving the benz[a]anthraquinone moiety of landomycinone. While landomycins generally do not display emissive properties, the respective Michael adducts exerted intense blue fluorescence in a glycosidic chain-dependent manner. This allowed label-free tracking of the short-lived nature of the mono-SH-adduct followed b…
Importancia del estrés oxidativo en la diferencia de longevidad entre machos y hembras
2003
Uno de los mayores logros del siglo XX es el aumento de la esperanza de vida de la población humana. En Europa, ésta se ha duplicado entre 1900 y 1992. En todos los casos la esperanza de vida de las mujeres supera a la de los hombres. De hecho, en España en 1900, la esperanza de vida para los hombres era de 33.7 años y para las mujeres de 35.1, es decir, un 3.8% superior en mujeres frente a hombres. En 1992 la esperanza de vida de los hombres era de 73.7 años, mientras que la de las mujeres era 83.8, lo cual supone un 9.9% más en las mujeres que en los hombres. La base de la diferencia de esperanza de vida entre machos y hembras está aún por esclarecer.Este fenómeno no es atribuible a difer…
Estudio de la concentración sérica del factor de crecimiento del endotelio vascular (VEGF) en el carcinoma vesical y de su relación con el estadio tu…
2003
El carcinoma vesical es el segundo tumor más frecuente del aparato genitourinario, es el quinto tumor más frecuente de los varones occidentales, y en nuestro país se estima una incidencia de 20 casos por cada 100.000 habitantes y año. En la actualidad es necesario encontrar nuevos indicadores pronósticos del carcinoma vesical que permitan identificar que tumores deben ser tratados precozmente de manera más intensa. La angiogénesis en el carcinoma vesical, expresada como densidad vascular en las piezas quirúrgicas, ha mostrado tener relación con el pronóstico del mismo. VEGF es una citosina multifuncional que ha mostrado tener gran relevancia en el proceso angiogénico. Hipótesis: Para el des…
Heterogeneidad genética de blastocystis hominis: implicaciones patogénicas.
2003
En los últimos años diversos trabajos ponen de manifiesto la existencia de variaciones intraespecíficas entre aislados de Blastocystis hominis. La descripción de diferentes perfiles proteicos, cariotipos y zimodemas constituyen pruebas de la posible existencia de poblaciones morfológicamente idénticas, que quizás estén dotadas de un potencial patogénico diferente. El objeto de este estudio es el de establecer asociaciones entre variantes genéticas y enzimáticas y distinta significación clínica, para lo cual se realizaron los siguientes procedimientos:(1) Obtener aislados clínicos de pacientes sintomáticos y asintomáticos, cultivarlos y axenizarlos.(2) Comprobar el grado de variación genétic…
Northern Hemisphere atmospheric pattern enhancing Eastern Mediterranean Transient-type events during the past 1000 years
2021
High-resolution climate model simulations for the last millennium were used to elucidate the main winter Northern Hemisphere atmospheric pattern during enhanced Eastern Mediterranean Transient (EMT-type) events, a situation in which an additional overturning cell is detected in the Mediterranean at the Aegean Sea. The differential upward heat flux between the Aegean Basin and the Gulf of Lion was taken as a proxy of EMT-type events and correlated with winter mean geopotential height at 500 mbar in the Northern Hemisphere (20–90∘ N and 100∘ W–80∘ E). Correlations revealed a pattern similar to the East Atlantic/Western Russian (EA/WR) mode as the main driver of EMT-type events, with the past …