Asunción Luquin

Rosa canina extracts have antiproliferative and antioxidant effects on caco-2 human colon cancer

The in vitro antiproliferative and antioxidant effects of different fractions of Rosa canina hips on human colon cancer cell lines (Caco-2) was studied. The compounds tested were total extract (fraction 1), vitamin C (fraction 2), neutral polyphenols (fraction 3) and acidic polyphenols (fraction 4). All the extracts showed high cytotoxicity after 72 h, both low and high concentrations. The flow cytometric analysis revealed that all the fractions produce disturbances in the cell cycle resulting in a concomitant cell death by an apoptotic pathway. Changes in the redox status of Caco-2 cells in response to Rosa canina hips were determined. Cells were exposed to hydrogen peroxide in presence of plant fractions and the production of Reactive Oxygen Species (ROS) was significantly decreased. Therefore, our data demonstrate that rosehip extracts are a powerful antioxidant that produces an antiproliferative effect in Caco-2 cells. Therefore, these results predict a promising future for Rosa canina as a therapeutic agent. Thus, this natural plant could be an effective component of functional foods addressed towards colorectal carcinoma.

Application of gold complexes in the development of sensors for volatile organic compounds

Two different kinds of sensors have been developed by using the same kind of vapochromic complexes. The vapochromic materials [Au2Ag2(C6F5)4L2]n have different colours depending on the ligand L. These materials change, reversibly, their optical properties, colour and fluorescence, in the presence of the vapours of volatile organic compounds (VOCs). For practical applications, two different ways of fixing the vapochromic material to the optical fibre have been used: the sol-gel technique and the electrostatic self-assembly method (ESA). With the first technique the sensors can even be used to detect VOCs in aqueous solutions, and using the second method it has been possible to develop nanosensors.

Remote sensing network to detect and identify organic vapours

In this work, a novel CWDM (Coarse Wavelength Division Multiplexing) network that multiplexes intensity modulated optical fibre sensors is presented. These transducers are based on a sensing material that suffers reversible changes in its optical properties in presence of organic vapours. This compound is fixed onto cleaved ended single mode optical fibres pigtails using Electrostatic Self-Assembly method. As their response depends on intensity changes, a referencing signal is simultaneously generated to eliminate the effect of optical source power fluctuations. Thus, a parallel array of phaseshifted fibre Bragg gratings (PS-FBGs) is included to obtain the referencing signal. Looking forward to remote sensing applications, an Erbium doped fibre amplifier (EDFA) is included in the header of the network to reach up to 4 km of distance. Four new sensors have been multiplexed and exposed to saturated atmospheres of methanol and ethanol individually, showing different response and recovery times in each case. Finally, we checked that our sensors were able to distinguish between pure and kerosene polluted water probes in terms of response and recovery times as well.

Chemical composition of rosehips from different Rosa species: an alternative source of antioxidants for the food industry

ABSTRACT It is important to explore new sources of natural additives because the demand for these compounds by consumers is increasing. These products also provide health benefits and help in food preservation. An unexplored source of nutrients and antioxidant compounds is rosehip, the fleshy fruit of roses. This work compares the antioxidant compound (vitamin C, neutral phenols and acidic phenols) content of four Rosa species rosehips: R. pouzinii, R. corymbifera, R. glauca and R. canina from different geographical zones. Results show quantitative variability in ascorbic acids and neutral phenols content, and quantitative and qualitative differences in acidic phenol content, depending on species. Vitamin C concentration was highly variable depending on species, R. canina being the one with the highest concentration and R. pouzinii the one with the lowest content. Variability was found in total neutral polyphenols concentration and a correlation between freshness of the rosehips and concentration of neutral polyphenols was also found. Significant differences were found in the acidic phenols content among the studied species. Generally antioxidant activity was higher in the vitamin C fraction.

Organic vapors detection using single mode fiber at third telecommunication window

An optical fiber sensor to detect Volatile Organic Compounds (VOCs) is presented in this work. A material that shows a color change (from orange to green) in presence of organic vapors, is fixed onto a cleaved ended pigtail by Electrostatic Self Assembly method [1]. This way, when an optical signal is guided to the device head, changes in the sensing material produce variations in the reflected optical power. Standard Mono mode fiber (9/125 µm) and a DBF laser (@ 1550nm) have been used. Typically, wider fibers (62.5/125 µm) and lower wavelengths (laying in the visible spectral) are used to measure the effect of color change, but working at 1550nm makes easier multiplexing several optical signals. A sensor was implemented and exposed to saturated concentrations of several VOCs, registering a change in the reflected optical power, especially significant for acetic acid.

Nuclear fission technology in Spain: History and social concerns

This research examines the evolution of nuclear technology in Spain from the early years of the Franco dictatorship to the global financial crisis and technology’s influence on Spanish culture. To this end, we take a sociological perspective, with science culture and social perceptions of risk in knowledge societies serving as the two elements of focus in this work. In this sense, this article analyses the transformation of social relationships in light of technological changes. We propose technology as a strategic place to observe the institutional and organisational dynamics of technologic-scientific risks, the expert role and Spain’s science culture. In addition, more specifically, within the language of co-production, we ‘follow the actor’ and favour new forms of citizen participation that promote ethics to discuss technological issues.

Improvement of wine aromatic quality using mixtures of lysozyme and dimethyl dicarbonate, with low SO2 concentration.

The use of sulphur dioxide (SO2) in the treatment of foodstuffs presents some problems as it could lead to pseudo-allergies in some people. The aim of this research work was to study the addition of different preservative mixtures and their influence on the concentration of volatile compounds and sensorial quality in wine. To do so, vinifications were carried out using Garnacha must to which lysozyme, dimethyl dicarbonate (DMDC) and mixtures of these with SO2 were added at different doses (25 and 50 mg l−1). The results were compared with a control sample to which only SO2 had been added (50 mg l−1). In general, mixtures of SO2 with lysozyme and DMDC favoured the formation of volatile compounds in the wines. Wines obtained from the mixtures of lysozyme and DMDC with 25 mg l−1 of SO2 had better sensorial quality than the wines obtained with 50 mg l−1 as the only preservative used.

A Series of [Ln(NO3)3(4’-(4-Bromophenyl)-2,2’:6’,2’’-Terpyridine)] Lanthanide Derivatives

Lanthanide complexes [Ln (NO3)3(4’-(4-bromophenyl)-2,2’:6’,2’’-terpyridine)]; being Ln all the non radiative lanthanide elements (1 – 14), have been synthesized and characterized by IR, 1H NMR, MALDI-MS and the X-ray structures of the La, Nd, Sm, Eu and Dy complexes, showing a linear comparison of the average M-O and M-N distances with the ionic radius or the number of f electrons of the lanthanides. The luminescence properties of complexes 4 (Nd), 5 (Sm), 6 (Eu), 8 (Tb), 9 (Dy) in the solid state and in the acetonitrile solutions of 5 (Sm) and 6 (Eu) are reported.