Modelo de planificación agregada para proyectos de fabricación/instalación de muros cortina

Este trabajo presenta un modelo de planificación agregada para la optimización de la producción e instalación de una empresa fabricadora de Muros Cortina, también llamados Sistemas de Fachada Ligera. Este producto está compuesto por una estructura de aluminio que se ubica por delante de la estructura de los edificios, sobre la cual se acoplan cristales. El objetivo de este estudio es diseñar un modelo de planificación agregada, que le permita a la empresa alcanzar mejores rendimientos en su actividad y la elaboración de presupuestos de buena calidad. De tal manera que los presupuestos diseñados se ajusten a los costos y operaciones reales, entregando como resultado las decisiones operacionales que se deben tomar para alcanzar las metas de la empresa. Para determinar algunos parámetros del modelo se recurrió al estudio de tiempos con cronómetro. Gracias a la implementación del modelo propuesto, se mejoró la planificación de la producción y la calidad de los presupuestos para participar en licitaciones.This paper presents a model of aggregate planning for the optimization of production and installation of Curtain Walls in a manufacturing company. This product is made out by a aluminum structure with crystal that it is installed in front of the buildings. The objective of this study is to design a model of aggregate  planning, that it allow finding better performances in the company activity, and allow elaborating good-quality budgets. In order that the designed budgets fit to the costs and real operations, giving up the operational decisions that should be done, in order to achieve the company goals. In order to determine some parameters of the model, times’ study with chronometer was used. Thanks to the implementation of the proposed model, the planning of production and the quality of the budgets got better

Control of targeting ligand display by pH-responsive polymers on gold nanoparticles mediates selective entry into cancer cells

Selective targeting of cells for intracellular delivery of therapeutics represents a major challenge for pharmaceutical intervention in disease. Here we show pH triggered receptor-mediated endocytosis of nanoparticles via surface ligand exposure. Gold nanoparticles were decorated with two polymers: a 2 kDa PEG with a terminal folate targeting ligand, and a di-block copolymer including a pH-responsive and a hydrophilic block. At the normal serum pH of 7.4, the pH-responsive block (apparent pKa of 7.1) displayed a hydrophilic extended conformation, shielding the PEG-folate ligands, which inhibited cellular uptake of the nanoparticles. Under pH conditions resembling those of the extracellular matrix around solid tumours (pH 6.5), protonation of the pH-responsive polymer triggered a coil-to-globule polymer chain contraction, exposing folate residues on the PEG chains. In line with this, endocytosis of folate-decorated polymer-coated gold nanoparticles in cancer cells overexpressing folate receptor was significantly increased at pH 6.5, compared with pH 7.4. Thus, the tumour acidic environment and high folate receptor expression was effectively exploited to activate cell binding and endocytosis of these nanoparticles. These data provide proof-of-concept for strategies enabling extracellular pH stimuli to selectively enhance cellular uptake of drug delivery vectors and their associated therapeutic cargo

Evidence of slow acoustic surface waves on a 1D phononic surface by a pulsed laser spectroscopic technique resolved in time and space

We report the investigation of surface acoustic waves (SAWs) propagating on a 1D phononic surface (PS) by the heterodyne-detected transient reflecting grating technique. A suitable experimental configuration enables the excitation of traveling SAWs with variable wave numbers and the measurement of their propagation with temporal and spatial resolution. Using the full characterization of the band diagram of this PS, as reported previously (Malfanti I., Taschin A., Bartolini P., Bonello B. and Torre R., J. Mech. Phys. Solids, 59 (2011) 2370), we studied the dispersion properties of the SAWs as the wave number approaches the Brillouin zone edge. SAW-packet group velocities show a clear slowing-down process approaching the BZ edge, with a measurable minimum velocity of about 140 m/

Propagation of acoustic surface waves on a phononic surface investigated by transient reflecting grating spectroscopy

International audienceWe present a study of surface acoustic waves (SAW) propagation on a 1D phononic surface (PS) by mean of an heterodyne-detected transient reflecting grating experiment. We excited and detected coherent stationary SAWs characterized by variable wave-vectors. The measured SAW frequencies enables the characterization of the band diagram of this PS sample beyond the first Brillouin zone (BZ). Four different SAW frequencies have been revealed, whose band diagram show articulated dispersion phenomena. In order to address the nature of the investigated SAWs, the experimental results are compared with a numerical simulation of elastic modes based on a finite element model. The observed SAWs are addressed to four Bloch waves characterized by different frequencies and surface energy localization. Moreover, we measured the SAW propagation on a flat non-phononic part of the sample surface and compared it with results from the PS. (C) 2011 Elsevier Ltd. All rights reserved

Modelo de planificación agregada para proyectos de fabricación/instalación de muros cortina

Este trabajo presenta un modelo de planificación agregada para la optimización de la producción e instalación de una empresa fabricadora de Muros Cortina, también llamados Sistemas de Fachada Ligera. Este producto está compuesto por una estructura de aluminio que se ubica por delante de la estructura de los edificios, sobre la cual se acoplan cristales. El objetivo de este estudio es diseñar un modelo de planificación agregada, que le permita a la empresa alcanzar mejores rendimientos en su actividad y la elaboración de presupuestos de buena calidad. De tal manera que los presupuestos diseñados se ajusten a los costos y operaciones reales, entregando como resultado las decisiones operacionales que se deben tomar para alcanzar las metas de la empresa. Para determinar algunos parámetros del modelo se recurrió al estudio de tiempos con cronómetro. Gracias a la implementación del modelo propuesto, se mejoró la planificación de la producción y la calidad de los presupuestos para participar en licitaciones. This paper presents a model of aggregate planning for the optimization of production and installation of Curtain Walls in a manufacturing company. This product is made out by a aluminum structure with crystal that it is installed in front of the buildings. The objective of this study is to design a model of aggregate  planning, that it allow finding better performances in the company activity, and allow elaborating good-quality budgets. In order that the designed budgets fit to the costs and real operations, giving up the operational decisions that should be done, in order to achieve the company goals. In order to determine some parameters of the model, times’ study with chronometer was used. Thanks to the implementation of the proposed model, the planning of production and the quality of the budgets got better

Dexamethasone loaded liposomes by thin\u2010film hydration and microfluidic procedures: Formulation challenges

Liposomes have been one of the most exploited drug delivery systems in recent decades. However, their large\u2010scale production with low batch\u2010to\u2010batch differences is a challenge for industry, which ultimately delays the clinical translation of new products. We have investigated the effects of formulation parameters on the colloidal and biopharmaceutical properties of liposomes generated with a thin\u2010film hydration approach and microfluidic procedure. Dexamethasone hemisuccinate was remotely loaded into liposomes using a calcium acetate gradient. The liposomes produced by microfluidic techniques showed a unilamellar structure, while the liposomes produced by thin\u2010film hydration were multilamellar. Under the same remote loading conditions, a higher loading capacity and efficiency were observed for the liposomes obtained by microfluidics, with low batch\u2010to\u2010batch differences. Both formulations released the drug for almost one month with the liposomes prepared by microfluidics showing a slightly higher drug release in the first two days. This behavior was ascribed to the different structure of the two liposome formulations. In vitro studies showed that both formulations are non\u2010toxic, associate to human Adult Retinal Pigment Epithelial cell line\u201019 (ARPE\u201019) cells, and efficiently reduce inflammation, with the liposomes obtained by the microfluidic technique slightly outperforming. The results demonstrated that the microfluidic technique offers advantages to generate liposomal formulations for drug\u2010controlled release with an enhanced biopharmaceutical profile and with scalability

The low frequency dynamics of supercooled LiBr, 6H2O

International audienceWe present results of a series of experiments performed on LiBr, 6H20 from room temperature down to 172 K ≈ 1.2Tg. These ultrasound, Brillouin and depolarized light scattering, and transient grating experiments show that, above 215 K, this solution behaves like supercooled water: its zero frequency sound velocity C0 continuously decreases with decreasing temperature, and the reorientational dynamics of the water molecules can be directly detected at some temperatures of this domain. Conversely, below 215 K, a new regime sets in, where the apparent C0 is practically temperature independent and where a β, Arrenhius like, relaxation process coexists with the usual, Vogel-Fulcher like, α relaxation process of the supercooled liquid. These results are similar to those recently obtained in LiCl, 6H2O. The onset of the new regime is possibly due to an increase of the interaction of the water molecules with a neighboring Li+ ion when lowering the temperature. We also compare our results with published dielectric data on water solutions of glass forming polyalcohols. Some of them present a low temperature splitting of their relaxation time similar to what is found in LiBr, 6H2

Oligo-guanidyl targeted bioconjugates forming rod shaped polyplexes as a new nanoplatform for oligonucleotide delivery

Novel bioconjugates (Agm6-M-PEG-FA) for active oligonucleotide (ON) delivery have been developed by conjugating a cationic oligo-guanidyl star-like shaped "head" (Agm6-M) to a polymeric "tail" (PEG) terminating with folic acid (FA) as targeting agent or methoxy group (Agm6-M-PEG-FA and Agm6-M-PEG-OCH3, respectively). Gel electrophoresis showed that the bioconjugates completely associated with ONs at 3 nitrogen/phosphate (N/P) ratio. Studies performed with folate receptor (FR)-overexpressing HeLa cells, showed that optimal cell up-take was obtained with the 75:25 w/w Agm6-M-PEG-OCH3:Agm6-M-PEG-FA mixture. Dynamic light scattering and transmission electron microscopy showed that the polyplexes had size <80\u202fnm with narrow polydispersity and rod-shaped morphology. The polyplexes were stable for several hours in plasma while ON was released in the presence of heparin concentration 16-times higher than the physiological one. The polyplexes displayed negligible cytotoxicity, hemolysis and low pro-inflammatory TNF-\u3b1 release. Studies performed with FR-overexpressing HeLa and MDA-MB-231 cells using siRac1 revealed that the folated polyplexes caused significantly higher gene silencing (86.1\u202f\ub1\u202f9.6%) and inhibition of cell migration (40%) than the non-folated polyplexes obtained with Agm6-M-PEG-OCH3 only. Although cytofluorimetric analyses showed similar cell uptake for both folated and non-folated polyplexes, confocal, TEM and competition studies showed that the folated polyplexes were taken-up by lysosome escaping caveolin-mediated pathway with final polyplex localization within cytosol, while non-folated polyplexes were preferentially taken-up via clathrin-mediated pathway to localize in the lysosomes. Finally, preliminary in vivo studies carried out in mice revealed that the folated polyplexes dispose in the tumor mass