Search

The region of La Rioja (Spain) is rich in paleontological sites, especially those related to dinosaur fossil footprints, of which more than 150 tracksites with more than 10,000 tracks have been described. The cataloging and systematic study of this heritage requires its correct location in space and the provision of an adequate geometric representation of both the distribution of remains in the sites and the three-dimensional shape of the different fossil elements. In this work, the various geometric documentation techniques used for this purpose (GNSS, photogrammetry and structured light scanner) are presented, as well as the description of the main products that are generated and their usefulness for the study, management, outreach activities and preservation of paleontological heritage in this region. These products will be key to the development of paleontological research projects and the development of educational and outreach tools. La región de La Rioja (España) es rica en yacimientos paleontológicos, especialmente aquellos relacionados con huellas fósiles de dinosaurios, de los cuales se han descrito más de 150 yacimientos con más de 10,000 huellas. La catalogación y el estudio sistemático de este patrimonio requieren su ubicación correcta en el espacio y la provisión de una representación geométrica adecuada tanto de la distribución de restos en los yacimientos como de la forma tridimensional de los diferentes elementos fósiles. En este trabajo, se presentan las diversas técnicas de documentación geométrica utilizadas para este fin (GNSS, fotogrametría y escáner de luz estructurada), así como la descripción de los principales productos que se generan y su utilidad para el estudio, la gestión, las actividades de divulgación y la preservación. De patrimonio paleontológico en esta región. Estos productos serán clave para el desarrollo de proyectos de investigación paleontológica y el desarrollo de herramientas educativas y de divulgación.

La existencia de un rico conjunto de monteas y trazados de arquitectura en el claustro bajo del monasterio de San Millán de la Cogolla, de Yuso, ha hecho necesario el desarrollo y la aplicación de una metodología que posibilite el registro, preservación y difusión, de modo abierto, de la información que atesoran sus muros. La documentación parte del calco directo de los trazos y la posterior digitalización y sobreimposición del dibujo sobre el modelo tridimensional fotogramétrico. Por su parte, la preservación y difusión en formato digital se establece a través de un repositorio institucional que se encuentra enlazado a través de Europeana. Los plásticos originales con los calcos directos han sido depositados en el archivo del monasterio. Asimismo, se ha desarrollado una aplicación de realidad aumentada que permite la recreación virtual de los trazos sobre los alzados del claustro de manera interactiva.

International audience; The most recent developments on Pickering emulsions deal with the design of responsive emulsions able to undergo fast destabilization under the effect of an external stimulus. In this scenario, soft colloidal particles like microgels are considered novel class suitable emulsifiers. Microgels particles self-assemblies are highly deformable at interfaces covering higher surfaces than hard particles and their interfacial behavior strongly depends on external-stimuli. Microgels are very diverse owing to the large variety of them from the point of view of possible combinations of stimuli-responsiveness and different microstructures (crosslinking density and distribution). Herein, we illustrate the use of different types of responsive microgels not only from a structural point of view but also even from physical one. For that, the effect of different microgels parameters such as internal structure and charge density on mechanical properties of the interface will be discussed.

Hypotheses The deformation and swelling ability of microgels is influenced by the crosslinking distribution. Varying microgels microstructure is expected to obtain suspensions with different flow behavior and thereby, different rheological properties. Experiments Different multi-responsive microgels were synthesized using two different crosslinkers and varying their amounts: N,N-methylene bis-acrylamide (MBA) and oligo(ethylene glycol) diacrylate (OEGDA). The rheological results were obtained by zero-shear viscosity and long-time creep measurements on concentrated microgel suspensions Microgel microstructure was analyzed by 1H nuclear magnetic resonance transverse relaxation measurements. Findings At a constant crosslinking rate, we show that the viscosity of OEGDA-crosslinked microgels diverges at a higher concentration than MBA ones, suggesting a looser shell and less restricted dangling chains at the periphery for the later. By scaling with the effective volume fraction, the viscosity curves of the different microgel suspensions reduce into a single curve and closely follow hard sphere models up to ϕeff

Nowadays, the design of innovative delivery systems is driving new product developments in the field of skincare. In this regard, serving as potential candidates for on-demand drug delivery and fulfilling advanced mechanical and optical properties together with surface protection, spontaneously self-assembled microgel films can be proposed as ideal smart skincare systems. Currently, the high encapsulation of more than one drug simultaneously in a film is a very challenging task. Herein, different ratios (1:1, 3:1, 9:1) of different mixtures of hydrophilic/hydrophobic UVA/UVB-absorbers working together in synergy and used for skin protection were encapsulated efficiently into spontaneously self-assembled microgel films. In addition, in vitro release profiles show a controlled release of the different active molecules regulated by the pH and temperature of the medium. The analysis of the release mechanisms by the Peppas–Sahlin model indicated a superposition of diffusion-controlled and swelling-controlled releases. Finally, the distribution of active molecule mixtures into the film was studied by confocal Raman microscopy imaging corroborating the release profiles obtained.

International audience; In an attempt to pave the way towards the substitution of petroleum-based monomers for monomers from sustainable and renewable resources, this work investigates the synthesis of a portfolio of new (meth)acrylic monomers using as raw materials terpenoids that can be conveniently extracted from wood waste and citrus fruits. The synthetic process is based on the enzymatic catalysis of the esterification of the terpenoids and it is solvent-, metal-, amino- and halogen-free, overcoming the limitations of the common esterification techniques. The effect of employing microwaves in combination with the enzyme as well as the effect of the acyl donor choice ((meth)acrylic acids vs. (meth)acrylic anhydrides) were studied. The process yielded complete conversion and then high purity monomers with a variety of structures that would allow them to substitute many of the most commonly used petrochemical (meth)acrylic monomers

International audience; Herein, cosmetic active molecule controlled encapsulation and release from multi-responsive oligo(ethylene glycol)-based biocompatible microgels are reported. The pH-responsiveness and pH-sensitive thermal-behavior of the microgel synthesized in different cosmetic buffered media has been demonstrated. The effective encapsulation of four different cosmetic active molecules (two hydrophilic and two hydrophobic) via short-distance local hydrophobic interactions and hydrogen-bonding interactions between the -OH groups of active molecules and ether oxygens of loaded-microgel particles has been studied by Diffusion Ordered Spectroscopy NMR (DOSY-NMR) and Nuclear Overhauser Enhancement Spectroscopy (NOESY-NMR) for the first time. In vitro release profiles have shown that cosmetic active molecule release can be controlled by the pH and temperature of the medium as well as by the medium hydrophobicity. In addition, under those conditions where microgel particles are swollen, the cosmetic active molecule release is controlled by Fickian diffusion and Case-II transport, the diffusional process being dominant. These results indicate that multi-responsive oligo(ethylene glycol)-based microgels are new potential vehicles to design cosmetic active delivery systems.

International audience; The present study aims in the understanding of the effect of oligo(ethylene glycol)-based biocompatible microgels inner structure on the encapsulation/release mechanisms of different types of cosmetic active molecules. For that, multi-responsive microgels were synthesized using three types of cross-linkers: ethylene glycol dimethacrylate (EGDMA), oligo(ethylene glycol) diacrylate (OEGDA) and N,N-methylenebisacrylamide (MBA). The inner morphology of the microgels synthesized was studied by 1H-nuclear magnetic resonance (1H NMR) and small-angle neutron scattering (SANS) techniques and no effect of cross-linker type on microgel microstructure was observed in the case of analysing purified microgel dispersions. Moreover, all the microgels synthesized presented conventional swelling/de-swelling behavior as a function of temperature and pH. Two hydrophobic, one hydrophilic, and one macromolecule as cosmetic active molecules were effectively loaded into different microgel particles via hydrophobic interactions and hydrogen-bonding interactions between −OH groups of active molecules and ether oxygens of different microgel particles. Their release profiles as a function of cross-linker type used and encapsulated amounts were studied by Peppas-Sahlin model. No effect of the cross-linker type was observed due to the similar inner structure of all the microgels synthesized.

The synthesis, characterization, and potential application as gene delivery systems of biodegradable dual-responsive core–shell nanogels based on poly(2-diethylaminoethyl) methacrylate (PDEAEMA) and poly(N-vinylcaprolactam) (PVCL) are reported. These core–shell nanogels, having a PDEAEMA-based core and a PVCL-based shell, were synthesized by batch seeded emulsion polymerization. An indepth study of their swelling behavior was carried out, which presented a dual-dependent thermo- and pH sensitivity. Core–shell nanogels synthesized formed complexes spontaneously through electrostatic interactions when mixing with small interfering RNA (siRNA) molecules. Moreover, the core–shell nanogel/siRNA complexes showed higher polyanion exchange resistance compared to that of the PDEAEMA-based nanogel/siRNA complexes, indicating that the PVCL-based shell enhanced the stability of the complexes. In vitro siRNA release profiles showed that siRNA release was controlled by the pH of the medium as well as by the crosslinking density of the PVCL-based shell. These results indicate that dual-responsive core–shell nanogels synthesized could be potentially useful as gene delivery systems. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016.

International audience; This article reports the ability of oligo(ethylene glycol)-based stimuli-responsive microgels to spontaneously form self-assembled microgel films under different conditions such as the presence or absence of water soluble polymers (WSP, formed during the microgel synthesis) and the type and/or amount of salt in the microgel dispersion. The unusually high encapsulation of four different cosmetically active molecules has been achieved via hydrophobic interactions and hydrogen-bonding interactions between the -OH groups of active molecules and ether functions of self-assembled microgel films. The loaded-films present absorption higher than 50% of the UVA-UVB wavelengths and can be used for skin protection against sun. The nature of the interactions was determined by NOESY-NMR spectroscopy in the gel state. Moreover, confocal microscopy was used to show that the water solubility of the active molecule plays a crucial role in obtaining a more homogeneous distribution in films after loading.

A thorough understanding of the morphology of the environmental sensitive nanogels was indispensable to obtain a deeper insight on their stimuli-responsive behavior. Therefore, in this work the colloidal characterization and the study of the inner morphology were related by using light scattering technique and 1H-nuclear magnetic resonance transverse relaxation measurements combined with the Flory–Rehner theory. Different biocompatible and dual-stimuli-sensitive nanogel particles based on poly(2-diethylaminoethyl) methacrylate were synthesized using three different crosslinkers: two bifunctional and one multifunctional. All the nanogels obtained had a core–shell type heterogeneous morphology, but they presented completely different swelling behaviors due to their different crosslinking points’ distribution and polymeric chains’ microstructure. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2017–2025

Thermo-responsive and biocompatible cross-linked nanocapsules were synthesized through dimethyldioctadecylammonium bromide (DODAB) vesicle templating. For this, firstly two random copolymers, N-vinylcaprolactam (VCL) and acrylic acid (AA), with different chain lengths but using the same monomer ratio, were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. These anionic random copolymers were adsorbed onto cationic DODAB vesicles. Then, biocompatible and thermo-responsive nanocapsules were obtained by semicontinuous emulsion polymerization under monomer-starved conditions for both the main monomer (VCL) and the cross-linker. Although in all the cases the typical thermal behavior of PVCL-based nanocapsules was observed, hysteresis between cooling and heating cycles was observed at low temperature in the case of non-cross-linked nanocapsules. This behavior was reduced using different types and amounts of cross-linkers. In addition, transmission electron microscopy (TEM) characterization demonstrated the successful formation of nanocapsules either with short or long random copolymers. The formation of stable nanocapsules was confirmed below and above the volume phase transition temperature (VPTT) by surfactant lysis experiments through optical density and DLS measurements in all the nanocapsules synthesized. These biocompatible and thermo-responsive nanocapsules could be suitable and potentially useful as nanocarriers for drug delivery.

Two new families of thermo-responsive and enzymatically degradable nanogels were synthesized by batch emulsion polymerization of N-vinylcaprolactam (VCL) with dextran methacrylates (Dex-MA) with different degrees of substitution (DS). The first family was prepared using different amounts of Dex-MA with high DS forming highly cross-linked nanogel particles with the typical thermal behavior of PVCL-based nanogels: below the volume phase transition temperature (VPTT) nanogel particles were swollen and above it they were collapsed. After their enzymatic degradation with dextranase, nanogel particles swelled due to the cleavage of some glucopyranosyl bonds of dextran, but preserved their identity. On the other hand, the second family was prepared using different amounts of Dex-MA with low DS forming slightly cross-linked nanogel particles with an anomalous thermal behavior. Surprisingly, above the VPTT of the nanogel particles monodisperse interparticle reversible aggregates were formed. In addition, after their enzymatic degradation, a release of reducing sugars together with an intense de-swelling due to the fragmentation of the nanogel structure was observed. Both nanogel families could be suitable for drug delivery in tissues or organs where dextranase is present.