Association of albumin or protamine to lipoplexes: enhancement of transfection and resistance to serum

The successful application of gene therapy depends on the availability of carriers to efficiently deliver genetic material into target cells. Such efficacy is strongly related to key parameters including serum resistance and protection of DNA.The complexes were tested in terms of their biological activity, in the absence or presence of serum, by following transfection activity. Interaction with plasma proteins was evaluated by immunoblotting, while cytotoxicity was assessed by the Alamar Blue assay. Extent of DNA protection was determined both by using ethidium bromide intercalation and DNase I digestion assays.Our results show that, depending on the charge ratio and on the lipid composition, albumin and protamine can be used (either individually or co-associated) to generate cationic liposome/DNA complexes fulfilling in vivo requirements, while exhibiting high levels of transfection activity. In the present work a novel cationic lipid was tested. It was demonstrated that 1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine (EPOPC):cholesterol (Chol) liposomes constitute a very promising carrier for gene delivery as illustrated by their enhancing effect on transfection, as compared with DOTAP-containing liposomes. Moreover, the biological activity of EPOPC-containing complexes is significantly improved upon association of albumin, even in the presence of 60% serum (namely for the 4/1 lipid/DNA charge ratio). Nevertheless, our studies also show that transfection activity mediated by DOTAP-containing complexes can be significantly enhanced upon pre-condensation of DNA with protamine.Co-association of HSA and protamine to lipoplexes ensures a high degree of DNA protection and results in high levels of transfection activity even in the presence of serum. Copyright © 2004 John Wiley & Sons, Ltd

Hormigón conductor con fibras de carbono recicladas para aplicaciones calefactables en mobiliario urbano

This paper presents a broad experimental study performed at laboratory and industrial facilities to develop conductive concrete for self-heating and de-icing applications in urban furniture. Self-heating capacity is achieved by the application of electric current through a highly dense matrix containing recycled carbon fibers and graphite flakes. Prisms and slabs were fabricated with two different conductive concretes and electrode con­figurations to characterize the electrical properties and heating performance. Finally, 3 benches with different electrode disposals were fabricated to assess the heating capacity in real-scale applications. The results presented indicate promising results about the use of recycled carbon fibers for electrothermal concrete applications and identify the electrode configuration that allows the most efficient heat transfer and reduction of temperature gradients within the heated element. Real-scale tests show that the current technology developed is potentially applicable at de-icing applications in climates where temperatures remain within the range of -3 or -5 ºC.Este artículo presenta un extenso trabajo experimental a escala laboratorio e industrial para desarrollar mobiliario urbano con hormigones conductores calefactables. La capacidad calefactable se alcanza mediante la aplicación de corriente eléctrica por una matriz de hormigón con fibras de carbono recicladas y escamas de grafito. Se fabricaron prismas y losas con dos hormigones conductores y distintas configuraciones de electrodos para caracterizar sus propiedades eléctricas y capacidad calefactora. Finalmente, se fabricaron 3 bancos para evaluar la capacidad de calentamiento en aplicaciones a escala real. Los resultados muestran el potencial de las fibras de carbono recicladas para su uso en aplicaciones electrotérmicas e identifican las configuraciones de elec­trodos más adecuadas para reducir los gradientes de temperatura dentro del elemento calefactado. Por último, los ensayos a escala real muestran que la tecnología desarrollada es potencialmente válida para aplicaciones de des-hielo en climas donde la temperatura varía entorno los -3 y -5 ºC

Development of conductive cementitious materials using recycled carbon fibres

Conductive cementitious materials have gained immense attention in recent years owing to the possibility of achieving multifunctional materials. The usual approach has been to incorporate carbonaceous nanomaterials and/or virgin carbon fibres into cementitious matrices. This paper presents the first research devoted to the development of conductive cementitious materials using recycled carbon fibres (rCFs). Four different types of PAN-based rCFs were studied, by varying the aspect ratio and supplying characteristics, in two concrete dosages: conventional and ultra-high-performance concrete mixes. Two mixing methods—dry and wet—commonly used to fabricate fibre-reinforced concrete were considered. The results obtained in our result have shown that wet mix method achieves better workability of the mixes and good dispersion of the fibres. Furthermore, electrical resistivity values in the range of 3–0.6 O m were obtained for rCF contents ranging from 0.2 to 0.8% in vol. The obtained results demonstrate the possibility of using rCF to develop multifunctional cementitious materials and thus enhance the possibility of using these materials from an industrial point of view. Furthermore, new possibilities are created for the recycling of carbon fibre composites to obtain high-added-value products.Peer ReviewedPostprint (author's final draft

Self-sensing concrete made from recycled carbon fibres

The electrical and piezo-resistive responses of recycled carbon fibre (rCF)-reinforced concrete is analysed in this article. Two different PAN-based rCFs (monofilament rCF and fibrillated rCF sheets) incorporated into dry concrete mix were investigated. Piezo-resistivity was evaluated by simultaneously monitoring the variation in the applied DC voltage during both flexural and compressive tests. Although both plain and rCF-reinforced concrete samples showed piezo-resistive responses, the latter show increased signal-to-noise-ratio and thus behave like self-sensing materials. The electrical behaviour suggests a mixed control owing to both ionic and electronic conductivity, with the dominant one depending on the rCF content and rCF dispersion. This work enhances the possibility of generalising the use of smart cementitious materials in the civil engineering industry.Peer ReviewedPostprint (author's final draft

Accepter n’est pas intégrer: Les langues et cultures d’origine vues par les enseignants au Portugal

Cet article présente les premiers résultats d’une vaste recherche réalisée en milieu scolaire portugais et dont les objectifs sont, d’une part, de comprendre la façon dont les enseignants, en milieu scolaire du centre du Portugal facilitent la mise en place de relations positives qui valorisent et reconnaissent la diversité linguistique et culturelle des élèves de minorités linguistiques et culturelles et, d’autre part, de savoir s’ils mobilisent les langues et cultures d’origine (LCO) dans leurs planifications, activités et discours en salle de classe.This article presents a first set of results of a broader research carried out in Portuguese schools and whose objectives are on the one hand to understand the form as the teachers interviewed, teaching in schools in central Portugal, facilitate or not the establishment of teaching-learning strategies that value and recognize the linguistic and cultural diversity of students of linguistic and cultural minorities, and on the other hand whether they mobilize heritage languages and cultures (HLC) in their planning, activities and discourses in the classroom.publishe

Transferrin lipoplex-mediated suicide gene therapy of oral squamous cell carcinoma in an immunocompetent murine model and mechanisms involved in the antitumoral response

Suicide gene therapy has been used for the treatment of a variety of cancers. We reported previously the in vitro efficacy of the Herpes Simplex Virus Thymidine kinase (HSV-tk)/ganciclovir (GCV) system to mediate cytotoxicity in oral squamous cancer cells, using transferrin (Tf)-lipoplexes, prepared from cationic liposomes composed of 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP) and cholesterol. In the present study, we evaluated the antitumoral efficacy mediated by this lipoplex formulation in two suicide gene therapy strategies, HSV-tk/GCV and cytosine deaminase (CD)/5-fluorocytosine (5-FC), using a syngeneic, orthotopic murine model for head and neck squamous cell carcinoma. The cellular and molecular events associated with the antitumoral response elicited by both the therapeutic approaches were investigated by analyzing tumor cell death, tumor-infiltrating immune cells and tumor cytokine microenvironment. Significant tumor reduction was achieved upon intratumoral delivery of HSV-tk or CD genes mediated by Tf-lipoplexes, followed by intraperitoneal injection of GCV or 5-FC, respectively. Enhanced apoptosis, the recruitment of NK cells, CD4 and CD8 T-lymphocytes and an increase in the levels of several cytokines/chemokines were observed within the tumors. These observations suggest that suicide gene therapy with lipoplexes modifies the tumor microenvironment, and leads to the recruitment of immune effector cells that can act as adjuvants in reducing the tumor size. © 2009 Nature Publishing Group All rights reserved

2D materials integrated in Si3N4 photonics platform

This is the final version of the article. Available from the publisher via the DOI in this record.In this paper, we discuss a back-end CMOS fabrication process for the large-scale integration of 2D materials on SOI (siliconon-insulator) platform and present a complete theoretical study of the change in the effective refractive index of 2D materialsenabled silicon nitride waveguide structures. The chemical vapour deposition (CVD) and liquid exfoliation fabrication methods are described for the fabrication of graphene, WS2 and MoS2 thin films. Finite-difference frequency-domain (FDFD) approach and the Transfer Matrix Method were used in order to mathematically describe these structures. The introduction of thin films of 2D material onto Si3N4 waveguide structures allows manipulation of the optical characteristics to a high degree of precision by varying the Fermi-level through the engineering of the number of atomically thin layers or by electrical tuning, for example. Based on the proposed tuning approach, designs of graphene, WS2 and MoS2 enabled Si3N4 micro-ring structures are presented for the visible and NIR range, which demonstrate versatility and desirable properties for a wide range of applications, such as bio-chemical sensing and optical communications.We acknowledge financial support from: The Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom via the EPSRC Centre for Doctoral Training in Electromagnetic Metamaterials (Grant No. EP/L015331/1) and also via Grant No. EP/N035569/1

Heritage languages of young people from linguistic and cultural minorities in Portuguese schools: monolingual temptation versus multilingual realities

The main purpose of this poster is to present a case study aimed at researching the multilingual repertoires of young people from a linguistic and cultural minority. Further, it analyzes the role of and the place given to heritage languages (HL) in the development of a multilingual and intercultural competence in schools. In the scope of this study, a survey was conducted using two online questionnaires distributed to students from a migrant background and teachers. These students and teachers attended two primary and secondary schools in the central region of Portugal during the academic year 2013–2014. The results show that the students value their HL and perceive them as an instrument of social interaction as well as identity construction and affirmation. Additionally, the results show that both school and teachers recognize and respect the students’ linguistic and cultural capital as well as their composite and plural identities. However, they do not take advantage of this in the classroom by not promoting activities that enrich their students’ cultural and linguistic culture. In this context, the possibilities for an education in/with HL, as a pedagogical and didactic project, are not yet present in the school curriculum and habitus, on the one hand, because there are no educational language policies that incorporate it, and on the other hand, because both school and teachers do not seem to value the role and usefulness of HL in the promotion of an intercultural and multilingual education

Low-cost acoustic design of a bat test room

Experiments with captive bats need a flight room that is acoustically neutral, especially when recording and analysing bat calls or the response of bats to certain sound stimuli. Our aim was to identify an isolation material with the best quality–price relationship to acoustically coat such a flight room. For this, we built a flight room divided into two compartments that were to be acoustically isolated from one another. Audible and infrasonic waves are difficult to attenuate with low-cost materials but the attenuation of ultrasounds is rather straightforward. We evaluated the absorbing capacities of different low-cost materials – felt fabric, polystyrene, egg boxes, egg boxes coated with felt fabric, absorbing pyramidal foams, polyurethane foams and cork. The material that showed the best quality–price relationship was the polyurethane foam of open cells (5 cm thickness), which was able to attenuate approximately 20 dB at ultrasonic frequencies

Mogelijke effecten van actualisatie van zoutschadefuncties van grondgebonden, beregende landbouwgewassen

De derving van de fysieke opbrengst van grondgebonden teelten die kunnen worden beregend wordt deels bepaald door het zoutgehalte van het beregeningswater. De kennis op grond waarvan deze opbrengstderving wordt berekend is gebaseerd op veelal buitenlands onderzoek uit de jaren vijftig van de vorige eeuw in andere klimaatzones. Deze methodiek blijkt op basis van recente resultaten van veldproeven en praktijkervaringen niet toepasbaar op de Nederlandse situatie, maar dat gebeurt desondanks nog wel. Recente resultaten van Nederlandse veldproeven en praktijkervaringen tonen aan dat de zouttolerantie van gewassen als aardappelen, suikerbieten en gras aanzienlijk groter is dan gedacht op basis van buitenlands onderzoek. Dit zou moeten leiden tot bijgestelde zouttolerantiefuncties voor deze - en wellicht ook andere - gewassen. Om een indruk te geven wat de effecten van een bijstelling van de zouttolerantie-functies op de berekende opbrengst zouden kunnen zijn heeft een consortium, bestaande uit Alterra, De Bakelse Stroom, Deltares, Acacia Water, LEI en het Zilt Proefbedrijf Texel hiernaar een ruimtelijke verkenning uitgevoerd. Gewasopbrengten zijn per waterschap/regio in laag Nederland berekend met de anno 2013 gehanteerde, en met bijgestelde (lees: ‘tolerantere’) zouttolerantiefuncties. In de analyse is de berekende derving van de gewasopbrengst alleen bepaald door zout in beregeningswater. Voor laag Nederland werd het 10% droge jaar 1989 doorgetrokken naar ‘warm’ 2050 (W+). Op basis hiervan is een eerste schatting gemaakt van de verandering van de modelmatige opbrengst (i.c. een toename) van €60 miljoen/jaar. Dit resultaat geeft aan dat er sprake is van handelingsruimte in het (toekomstige) zoetwaterbeheer. Geadviseerd wordt om de zouttolerantiefuncties van landbouwgewassen te actualiseren, en om te kijken naar mogelijke consequenties voor de inrichting en het beheer van onze zoetwateraanvoersystemen