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1.
Nanoscale ; 13(34): 14572, 2021 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-34473189

RESUMEN

Correction for 'Galenic Lab-on-a-Chip concept for lipid nanocapsules production' by Nicolas Rolley et al., Nanoscale, 2021, 13, 11899-11912, DOI: 10.1039/D1NR00879J.

2.
Nanoscale ; 13(27): 11899-11912, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-34190298

RESUMEN

The continuous production of drug delivery systems assisted by microfluidics has drawn a growing interest because of the high reproducibility, low batch-to-batch variations, narrow and controlled particle size distributions and scale-up ease induced by this kind of processes. Besides, microfluidics offers opportunities for high throughput screening of process parameters and the implementation of process characterization techniques as close to the product as possible. In this context, we propose to spotlight the GALECHIP concept through the development of an instrumented microfluidic pilot considered as a Galenic Lab-on-a-Chip to formulate nanomedicines, such as lipid nanocapsules (LNCs), under controlled process conditions. In this paper we suggest an optimal rational development in terms of chip costs and designs. First, by using two common additive manufacturing techniques, namely fused deposition modelling and multi-jet modelling to prototype customized 3D microfluidic devices (chips and connectors). Secondly, by manufacturing transparent Silicon (Si)/Glass chips with similar channel geometries but obtained by a new approach of deep reactive ion etching (DRIE) technology suitable with in situ small angle X-ray scattering characterizations. LNCs were successfully produced by a phase inversion composition (PIC) process with highly monodispersed sizes from 25 nm to 100 nm and formulated using chips manufactured by 3D printing and DRIE technologies. The transparent Si/Glass chip was also used for the small angle X-ray scattering (SAXS) analysis of the LNC formulation with the PIC process. The 3D printing and DRIE technologies and their respective advantages are discussed in terms of cost, easiness to deploy and process developments in a GALECHIP point of view.


Asunto(s)
Dispositivos Laboratorio en un Chip , Nanocápsulas , Lípidos , Reproducibilidad de los Resultados , Dispersión del Ángulo Pequeño , Difracción de Rayos X
3.
Food Chem ; 346: 128804, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33418411

RESUMEN

Fruity beers can be promoted through production of flavoring compounds during fermentation by partial replacement of brewing yeast by non-conventional-yeasts with high aroma production abilities. We evaluated here the use of a wild Saprochaete suaveolens strain, producing atypical aroma compounds, to produce new natural fruity beer, while keeping classical production conditions used in brewing industry. S. suaveolens was inoculated as starter of culture during beer fermentation and the fermentation performance was evaluated through measurement of several physicochemical parameters. The aroma profile of the engineered beers was monitored using HS-SPME GC/MS. The results showed that high fruity aroma and low-ethanol content beers were obtained through single-fermentation using S. suaveolens. We also demonstrated that during mixed-fermentation, S. suaveolens maintained high metabolic activity and allowed production of beer enriched with fruity aroma. Production of high or low ethanol content fruity beer could be achieved by varying the composition of the starter of culture.


Asunto(s)
Fermentación , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Cerveza/análisis , Aromatizantes/análisis , Frutas/química , Geotrichum/metabolismo , Odorantes/análisis
4.
Microsyst Nanoeng ; 7: 8, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33489307

RESUMEN

Acoustic wave resonators are promising candidates for gravimetric biosensing. However, they generally suffer from strong acoustic radiation in liquid, which limits their quality factor and increases their frequency noise. This article presents an acoustic radiation-free gravimetric biosensor based on a locally resonant surface phononic crystal (SPC) consisting of periodic high aspect ratio electrodes to address the above issue. The acoustic wave generated in the SPC is slower than the sound wave in water, hence it prevents acoustic propagation in the fluid and results in energy confinement near the electrode surface. This energy confinement results in a significant quality factor improvement and reduces frequency noise. The proposed SPC resonator is numerically studied by finite element analysis and experimentally implemented by an electroplating-based fabrication process. Experimental results show that the SPC resonator exhibits an in-liquid quality factor 15 times higher than a conventional Rayleigh wave resonator at a similar operating frequency. The proposed radiation suppression method using SPC can also be applied in other types of acoustic wave resonators. Thus, this method can serve as a general technique for boosting the in-liquid quality factor and sensing performance of many acoustic biosensors.

5.
Appl Opt ; 58(7): 1757-1762, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30874213

RESUMEN

Lithium niobate (LN)-based devices are widely used in integrated and nonlinear optics. This material is robust and resistive to high temperatures, which makes the LN-based devices stable, but challenging to fabricate. In this work, we report on the design, manufacturing, and characterization of engineered dielectric media with thin-film LN (TFLN) on top for the coupling and propagation of electromagnetic surface waves at telecommunication wavelengths. The designed one-dimensional photonic crystal (1DPhC) sustains Bloch surface waves (BSWs) at the multilayer-air interface at 1550 nm wavelength with a propagation detected over a distance of 3 mm. The working wavelength and improved BSW propagation parameters open the way for exploration of nonlinear properties of BSW-based devices. It is also expected that these novel devices potentially would be able to modify BSW propagation and coupling by external thermal-electrical stimuli due to the improved quality of the TFLN top layer of 1DPhC.

6.
Rev Sci Instrum ; 89(1): 015005, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29390662

RESUMEN

We present the principle for a micro-sensor aimed at measuring local correlations of turbulent velocity and temperature. The operating principle is versatile and can be adapted for various types of flow. It is based on a micro-machined cantilever, on the tip of which a platinum resistor is patterned. The deflection of the cantilever yields an estimate for the local velocity, and the impedance of the platinum yields an estimate for the local temperature. The velocity measurement is tested in two turbulent jets: one with air at room temperature which allows us to compare with well-known calibrated reference anemometers, and another one in the GReC jet at CERN with cryogenic gaseous helium which allows a much larger range of resolved turbulent scales. The recording of temperature fluctuations is tested in the Barrel of Ilmenau which provides a controlled turbulent thermal flow in air. Measurements in the wake of a heated or cooled cylinder demonstrate the capability of the sensor to display the cross correlation between temperature and velocity correctly.

7.
Appl Spectrosc ; 71(7): 1568-1577, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28664784

RESUMEN

Due to its impressive optical properties, lithium niobate (LiNbO3) is considered to be one of the most important ferroelectric materials. Its uses in sensing platforms require functionalization at the surface to enable the capture and quantifying of molecules. The current paper aims to demonstrate the covalent bonding of aminosilane layers to the LiNbO3 surface. Fourier transform infrared (FT-IR) analysis reveals the presence of an NbO-Si bond observable as a shoulder at the same wavenumber (975 cm-1) on the surfaces of LiNBO3 as well as on those of Nb2O5, using 3-(aminopropyl)trimethoxysilane (APTMS) or 3-(aminopropyl)methyldimethoxysilane (APDMS) precursors. This covalent bonding is confirmed by the insolubility of the silane coating in dimethyl sulfoxide (DMSO). A kinetic study of the aminosilane layer growth obtained by quantitative FT-IR analysis is also carried out.

8.
Biomed Opt Express ; 2(5): 1307-18, 2011 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-21559142

RESUMEN

Position-referenced microscopy (PRM) is based on smart sample holders that integrate a position reference pattern (PRP) in their depth, allowing the determination of the lateral coordinates with respect to the sample-holder itself. Regions of interest can thus be retrieved easily after culture dish transfers from a cell incubator to the microscope stage. Images recorded at different instants in time are superimposed in a common coordinate system with subpixel accuracy. This paper presents such smart Petri culture dishes and their use for live cell culture monitoring. The impact of the PRP on the light budget is discussed and performances are demonstrated. First results on the application of PRM to the observation of apoptotic body internalization are reported.

9.
Anal Chim Acta ; 597(2): 313-21, 2007 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-17683745

RESUMEN

A new type of pH biosensor was developed for biological applications. This biosensor was fabricated using silicon microsystem technology and consists in two platinum microelectrodes. The first microelectrode was coated by an electrosynthesized polymer and acted as the pH sensitive electrode when the second one was coated by a silver layer and was used as the reference electrode. Then, this potentiometric pH miniaturized biosensor based on electrosynthesized polypyrrole or electrosynthesized linear polyethylenimine films was tested. The potentiometric responses appeared reversible and linear to pH changes in the range from pH 4 to 9. More, the responses were fast (less than 1 min for all sensors), they were stable in time since PPy/PEI films were stable during more than 30 days, and no interference was observed. The influence of the polymer thickness was also studied.


Asunto(s)
Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Electrones , Etilenodiaminas/síntesis química , Polietileneimina/síntesis química , Electroquímica , Etilenodiaminas/química , Concentración de Iones de Hidrógeno , Lactonas , Microscopía de Fuerza Atómica , Oxidación-Reducción , Polietileneimina/química , Polímeros/química , Pirroles/química , Plata , Factores de Tiempo
10.
Pain Pract ; 7(2): 103-9, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17559479

RESUMEN

Intrathecal and epidural opioid analgesia represents a major advance in the management of cancer pain, adding a new dimension to opioid therapy by allowing prolonged analgesia through the use of significantly lower doses than those required for systemic administration. However, myths, misconceptions, and apprehension continue to serve as major barriers to effective cancer pain management, and concerns regarding safety, efficacy, and relative ease of utilization still prevail. This, in turn, results in unnecessary suffering, depression, diminished cognitive function, sleep disturbance, functional disability, and compromised quality of life. We conducted a survey to systematically explore medical and paramedical attitudes prior to and 4 years after the introduction an interventional pain program and attempted to qualitatively analyze what appeared as main facilities or difficulties following end-of-life clinical experiences. In general we found that all caregivers were satisfied from using interventional pain relief techniques at the end-of-life; more so among caregivers directly involved in patient care. Although nearly half of the responders initially found "technical manipulations" moderately difficult to difficult, after a simple hands-on instruction all found these techniques to be "helpful, simple and feasible." "When all went well," caregivers found implantable devices as a useful tool to relieve pain, to increase the ability of patients to complete personal endeavors, notably mobilization, but also noted an increased patient anxiety at the end-of-life. "When all went wrong," caregivers evoked the paradoxical attitude of patients to having a "high-tech" treatment at the end-of-life, causing them eventually to have "false hope," as well as the phenomenon of "interdisciplinary hyperactivity," creating what was referred to as therapeutic futility. In summary, this study suggests the importance on insisting to introduce novel techniques into practice despite initial apprehension, however, quality improvement by detecting and overcoming attitudinal barriers remain primordial and requires narrative research.


Asunto(s)
Cuidadores/psicología , Conocimientos, Actitudes y Práctica en Salud , Dolor/enfermería , Dolor/psicología , Cuidados Paliativos , Cuidado Terminal , Cuidadores/estadística & datos numéricos , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Estudios Retrospectivos , Encuestas y Cuestionarios
11.
J Environ Monit ; 7(4): 357-64, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15798803

RESUMEN

Lidar measurements of temperature for the upper troposphere and lower stratosphere are commonly derived by the Raman technique. Lidar signals derived from vibrational Raman processes have been subjected to numerous simulation tests to examine their sensitivity to the presence of aerosols and ozone in the atmosphere. The influence of aerosols characteristics (wavelength dependence of aerosol extinction and particle phase function) and of ozone concentration on Raman temperature profiles is estimated. Simulations indicate large temperature deviations for post-volcanic conditions. For a Raman backscatter at 607 nm, bias is below 1 K for a total optical depth less than 9 x 10(-3) in the case of a stratospheric contamination and less than 6 x 10(-3) for a tropospheric contamination. The effect of aerosols depends on phase function and a few parameters such as altitude, optical depth and the shape of the high-altitude cloud. The wavelength dependence of aerosol extinction has some influence only for severe post-volcanic conditions (Scattering Ratio, SR >2). For a Raman backscatter at 387 nm, bias is larger and can be significant even in background aerosol conditions. Changes in the ozone density profile lead to significant Raman temperature deviations only for some specific conditions. Results suggest that both aerosol and ozone corrections are necessary to obtain an accuracy better than the 1 K requested for most atmospheric applications.


Asunto(s)
Aerosoles/análisis , Atmósfera/análisis , Monitoreo del Ambiente/métodos , Ozono/análisis , Espectrometría Raman/métodos , Sensibilidad y Especificidad , Temperatura
12.
Biosens Bioelectron ; 19(6): 595-606, 2004 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-14683643

RESUMEN

Potentiometric pH sensors based on linear polyethylenimine (L-PEI) and linear polypropylenimine(L-PPI), two synthetic enzymes and biocompatible polymers, films were prepared by electropolymerization of three different monomers: ethylenediamine (EDA), 1,3-diaminopropane (1,3-DAP) and diethylenetriamine (DETA) in order to be used in clinical, dermatological and biological applications, such as in vivo analysis. In a first step a biosensor was tested which consisted in a platinum wire protruded from glass sheath. The polymer film coated on these platinum electrodes showed good linear potentiometric responses to pH changes from pH 3 to 10. Resulting electrodes present both good reversibility and good stability versus time. The effect of the different polymer film thicknesses to potentiometric responses was also studied. This study allowed us to develop a miniaturized pH biosensor in the second step. This sensor was fabricated using photo-lithography, followed by sputtering and lift-off processes, and it included an electronic detection system. We have also successfully studied the potentiometric responses to pH changes of this device over a period of 1 month, and so we propose this new pH micro-biosensor as an alternative to classical pH sensors currently used in dermatology.


Asunto(s)
Materiales Biocompatibles/química , Técnicas Biosensibles/instrumentación , Electroquímica/instrumentación , Electrodos , Concentración de Iones de Hidrógeno , Polietileneimina/química , Polipropilenos/química , Materiales Biocompatibles/síntesis química , Técnicas Biosensibles/métodos , Electroquímica/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Miniaturización , Polímeros/síntesis química , Polímeros/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Propiedades de Superficie
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