2,926 research outputs found

    Color Engineering of Silicon Nitride Surfaces to Characterize the Polydopamine Refractive Index

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    A simple methodology to generate polydopamine (PDA) surfaces featured with color due to thin-film interference phenomena is presented. It is based on depositing ultra-thin films of polydopamine on a Si/Si 3 N 4 wafer that exhibits an interferential reflectance maximum right at the visible/UV boundary (∼400 nm). Therefore, a small deposit of PDA modifies the optical path, in such manner that the wavelength of the maximum of reflectance red shifts. Because the human eye is very sensitive to any change of the light spectral distribution at the visible region, very small film thickness changes (∼30 nm) are enough to notably modify the perceived color. Consequently, a controlled deposit of PDA, tune the color along the whole visible spectrum. Additionally, good quality of PDA deposits allowed us to determine the refractive index of polydopamine by ellipsometry spectroscopy. This data can be crucial in confocal skin microscopic techniques, presently used in diagnosis of skin tumors.Fil: Vega Moreno, Milena Amparo. Universidad de Salamanca; EspañaFil: Martín del Valle, Eva M.. Universidad de Salamanca; EspañaFil: Perez, Maximiliano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Pecharromán, Carlos. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia de los Materiales de Barcelona; EspañaFil: Marcelo, Gema. Universidad de Salamanca; Españ

    The relevance of knowledge transfer for universities' efficiency scores: An empirical approximation on the Spanish public higher education system

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    This article examines how knowledge transfer (KT) indicators affect analyses on efficiency in the Higher Education sector, taking into account the characteristics of the Higher Education Institutions (HEIs). After revising the concept of third mission as a field for data development and its importance in assessing university performance, we applied various data envelopment analysis models with different specifications to 47 Spanish public universities to test whether KT indicators are relevant when evaluating the performance of HEIs in terms of their efficiency and, if so, which indicators are most suitable. Our results suggest that the effect of including KT indicators in the efficiency analyses varies from university to university according to their characteristics. The subject mix taught at the university, the focus according to each mission's relative importance within the total range of activities carried out in each university (mission mix), and the mix of their third mission activities affect the increase of the universities' efficiency scores when KT is taken into account in the analysis. This means that these factors affect the universities' position for the different efficiency score

    First detection of Gongylonema species in Geotrupes mutator in Europe

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    The detection of three Gongylonema sp. infective larvae in two specimens of the dung beetle Geotrupes mutator (Marsham, 1802) from western Spain is reported here for the first time in Europe. Scanning electron microscopy confirmed that the analyzed specimens belong to the genus Gongylonema, but it was not possible to determine the species identity by the lack of morphological information in the literature and because many of the phenotypic characteristics had not yet fully developed at this juvenile stage. Nevertheless, a phylogenetic analysis using amplified cox1 nucleotide sequences has revealed that the studied larvae could be clearly discriminated ( 89% identity) from all the other Gongylonema cox1 sequences available in public genetic databases. While our results are limited by the scarcity of genetic information available for this genus, the possibility that the analyzed specimens might correspond to a new species should not be ruled out, and more studies are needed. The results provided in this report indicate that G. mutator is involved in the transmission cycle of Gongylonema sp.To vertebrates in Europe.publishersversionpublishe

    Comparing university performance by legal status: a Malmquist-type index approach for the case of the Spanish higher education system

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Tertiary Education and Management on 2017, available online: http://www.tandfonline.com/10.1080/13583883.2017.1296966New public management and increasing levels of competition driven by global rankings are bringing the managerial practices of public and private higher education institutions closer together. However, these two types of institutions still maintain different objectives and traditions and enjoy different degrees of autonomy that are reflected in their internal organisational structures. We study the relative efficiency and productivity performance of private and public universities in Spain through two adaptations of the Malmquist Index. Results show that, in 2009/2010, the greater flexibility of private universities meant a better adjustment between inputs and outputs in the private sector. However, in 2013/2014, public universities had caught up with private universities. Because of the economic crisis, the inputs of public universities have decreased, but this decrease had not fully impacted their results in 2013/201

    Simultaneous stimulation of arsenic methylation and inhibition of cadmium bioaccumulation in rice grain using zero valent iron and alternate wetting and drying water management

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    Acknowledgements Authors are grateful to The UK government for supporting this work through the Commonwealth Scholarship awarded to Angstone Thembachako Mlangeni, commonwealth scholar (MWCS-2015-334). ATM further acknowledges technical support from Luke David Harrold, Michael William Mcgibbon and David Robert Galloway. ATM also acknowledges continued family financial support from Lilongwe University of Agriculture and Natural Resources (through the Natural Resources College, Malawi) duration the entire study period in UK.Peer reviewedPostprin

    Molecular cloning and characterisation of the RESA gene, a marker of genetic diversity of Plasmodium falciparum

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    To identity immunodiagnostic antigen genes, a Plasmodium falciparum (Dd2 clone) expression library was screened using human immune sera. The ring-infected erythrocyte surface antigen (RESA) was isolated: this antigen of the resistant clone presents repeat tandem sequences like the 3D7 clone, albeit in different numbers. RESA has been studied as a marker of genetic diversity, with different sizes being observed in different isolates and clones of Plasmodium falciparum. The native protein was localised in cultures by western-blot and immuno-transmission electron microscopy. The antigenicity of RESA was evaluated by ELISA, using the carboxy-terminal repeat region as antigen. The assay’s sensitivity and specificity were 78.2 and 94% respectively

    Supervision of milk coagulation with scatter red LED light

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    For cheese production clotting time is prederteminated using a proteolytic enzyme titulation test (Chamorro and Losada 2002). Thus an expert operator decides the optimum cutting time (always delayed compared to clotting time) based on his own subjective evaluation of textural and visual properties of the curd (Castillo et al. 2000). Expert judgment usually gives acceptable results, yet variability in the optimal assessment of cutting time leads to affects further cheese processing operations (pressing and ripening). The aforementioned reasons suggest the importance of an objective and non-destructive method to determinate optimal cutting time, which would allow indeed the automatic supervision of the cheese clotting process. The goal of this work is a prospective study for the supervision of milk coagulation with scatter red LED light

    Dissolving microneedles for DNA vaccination: Improving functionality via polymer characterisation and RALA complexation

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    DNA vaccination holds the potential to treat or prevent nearly any immunogenic disease, including cancer. To date, these vaccines have demonstrated limited immunogenicity in vivo due to the absence of a suitable delivery system which can protect DNA from degradation and improve transfection efficiencies in vivo. Recently, microneedles have been described as a novel physical delivery technology to enhance DNA vaccine immunogenicity. Of these devices, dissolvable microneedles promise a safe, pain-free delivery system which may simultaneously improve DNA stability within a solid matrix and increase DNA delivery compared to solid arrays. However, to date little work has directly compared the suitability of different dissolvable matrices for formulation of DNA-loaded microneedles. Therefore, the current study examined the ability of 4 polymers to formulate mechanically robust, functional DNA loaded dissolvable microneedles. Additionally, complexation of DNA to a cationic delivery peptide, RALA, prior to incorporation into the dissolvable matrix was explored as a means to improve transfection efficacies following release from the polymer matrix. Our data demonstrates that DNA is degraded following incorporation into PVP, but not PVA matrices. The complexation of DNA to RALA prior to incorporation into polymers resulted in higher recovery from dissolvable matrices, and increased transfection efficiencies in vitro. Additionally, RALA/DNA nanoparticles released from dissolvable PVA matrices demonstrated up to 10-fold higher transfection efficiencies than the corresponding complexes released from PVP matrices, indicating that PVA is a superior polymer for this microneedle application

    The Use of a Pressure-Indicating Sensor Film to Provide Feedback upon Hydrogel-Forming Microneedle Array Self-Application In Vivo

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    PURPOSE: To evaluate the combination of a pressure-indicating sensor film with hydrogel-forming microneedle arrays, as a method of feedback to confirm MN insertion in vivo. METHODS: Pilot in vitro insertion studies were conducted using a Texture Analyser to insert MN arrays, coupled with a pressure-indicating sensor film, at varying forces into excised neonatal porcine skin. In vivo studies involved twenty human volunteers, who self-applied two hydrogel-forming MN arrays, one with a pressure-indicating sensor film incorporated and one without. Optical coherence tomography was employed to measure the resulting penetration depth and colorimetric analysis to investigate the associated colour change of the pressure-indicating sensor film. RESULTS: Microneedle insertion was achieved in vitro at three different forces, demonstrating the colour change of the pressure-indicating sensor film upon application of increasing pressure. When self-applied in vivo, there was no significant difference in the microneedle penetration depth resulting from each type of array, with a mean depth of 237 μm recorded. When the pressure-indicating sensor film was present, a colour change occurred upon each application, providing evidence of insertion. CONCLUSIONS: For the first time, this study shows how the incorporation of a simple, low-cost pressure-indicating sensor film can indicate microneedle insertion in vitro and in vivo, providing visual feedback to assure the user of correct application. Such a strategy may enhance usability of a microneedle device and, hence, assist in the future translation of the technology to widespread clinical use

    High plasticity of axonal pathology in Alzheimer's disease mouse models

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    Axonal dystrophies (AxDs) are swollen and tortuous neuronal processes that are associated with extracellular depositions of amyloid beta (Abeta) and have been observed to contribute to synaptic alterations occurring in Alzheimer's disease. Understanding the temporal course of this axonal pathology is of high relevance to comprehend the progression of the disease over time. We performed a long-term in vivo study (up to 210 days of two-photon imaging) with two transgenic mouse models (dE9xGFP-M and APP-PS1xGFP-M). Interestingly, AxDs were formed only in a quarter of GFP-expressing axons near Abeta-plaques, which indicates a selective vulnerability. AxDs, especially those reaching larger sizes, had long lifetimes and appeared as highly plastic structures with large variations in size and shape and axonal sprouting over time. In the case of the APP-PS1 mouse only, the formation of new long axonal segments in dystrophic axons (re-growth phenomenon) was observed. Moreover, new AxDs could appear at the same point of the axon where a previous AxD had been located before disappearance (re-formation phenomenon). In addition, we observed that most AxDs were formed and developed during the imaging period, and numerous AxDs had already disappeared by the end of this time. This work is the first in vivo study analyzing quantitatively the high plasticity of the axonal pathology around Abeta plaques. We hypothesized that a therapeutically early prevention of Abeta plaque formation or their growth might halt disease progression and promote functional axon regeneration and the recovery of neural circuits
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