212 research outputs found

    Recognition of Handwriting from Electromyography

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    Handwriting – one of the most important developments in human culture – is also a methodological tool in several scientific disciplines, most importantly handwriting recognition methods, graphology and medical diagnostics. Previous studies have relied largely on the analyses of handwritten traces or kinematic analysis of handwriting; whereas electromyographic (EMG) signals associated with handwriting have received little attention. Here we show for the first time, a method in which EMG signals generated by hand and forearm muscles during handwriting activity are reliably translated into both algorithm-generated handwriting traces and font characters using decoding algorithms. Our results demonstrate the feasibility of recreating handwriting solely from EMG signals – the finding that can be utilized in computer peripherals and myoelectric prosthetic devices. Moreover, this approach may provide a rapid and sensitive method for diagnosing a variety of neurogenerative diseases before other symptoms become clear

    DNA Aptamers against the Lup an 1 Food Allergen

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    Using in vitro selection, high affinity DNA aptamers to the food allergen Lup an 1, ß-conglutin, were selected from a pool of DNA, 93 bases in length, containing a randomised sequence of 49 bases. ß-conglutin was purified from lupin flour and chemically crosslinked to carboxylated magnetic beads. Peptide mass fingerprinting was used to confirm the presence of the ß-conglutin. Single stranded DNA was generated from the randomised pool using T7 Gene 6 Exonuclease and was subsequently incubated with the magnetic beads and the captured DNA was released and amplified prior to a further round of Systematic Evolution of Ligands by Exponential Enrichment (SELEX). Evolution was monitored using enzyme linked oligonucleotide assay and surface plasmon resonance. Once a plateau in evolution was reached, the isolated DNA sequences were cloned and sequenced. The consensus motif was identified via alignment of the sequences and the affinities of these sequences for immobilised ß-conglutin were determined using surface plasmon resonance. The selected aptamer was demonstrated to be highly specific, showing no cross-reactivity with other flour ingredients or with other conglutin fractions of lupin. The secondary structures of the selected aptamers were predicted using m-fold. Finally, the functionality of the selected aptamers was demonstrated using a competitive assay for the quantitative detection of ß-conglutin. . Future work will focus on structure elucidation and truncation of the selected sequences to generate a smaller aptamer for application to the analysis of the Lup an 1 allergen in foodstuffs

    Residual effects of natural Zn chelates on navy bean response, Zn leaching and soil status

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    greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the aging and residual effects of three natural organic Zn chelates [Zn-ethylenediaminedisuccinate (Zn-EDDS), Zn-polyhydroxyphenylcarboxylate and Zn-aminelignosulfonate] each administered in a single application to a first navy bean (Phaseolus vulgaris L.) crop at several different Zn application rates. In a second navy bean crop, we determined the following parameters: the extent of Zn leaching, the amount of available Zn remaining in soils, the amount of easily leachable Zn, the size of Zn fractions in soils, the pH and redox potential, the dry matter yield, and the soluble and total Zn concentrations in plants. The residual effect after 2 years of Zn fertilization mainly depended on the aging effect of Zn chelates and losses due to Zn leaching. The data relating to the evolution from the first to the second crop showed that the aging effect was noticeable in the calcareous soil. In the latter soil, the Zn-S,S-EDDS treatments showed greater decreases in the Zn uptake by plants than the other Zn treatments and the greatest Zn uptake by plants occurred when Zn was applied as Zn-aminelignosulfonate (10 mg Zn kg−1 rate, 6.85 mg Zn per lysimeter; 5 mg Zn kg−1 rate, 3.36 mg Zn per lysimeter). In contrast, in the calcareous soil, the maximum amount of Zn uptake, for the three chelates was 0.82 mg Zn per lysimeter. Consequently, a further application of Zn would be needed to prevent Zn deficiencies in the plants of a subsequent crop. The behaviour of the pH and Eh parameters in the soils and leachates did not depend on the natural Zn sources applied. In this study, the easily leachable Zn estimated by BaCl2 extraction was not adequate to predict Zn leaching from the soils in subsequent crops

    Influence of soil type and natural Zn chelates on flax response, tensile properties and soil Zn availability

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    A greenhouse experiment was conducted on weakly acidic and calcareous soils to evaluate the relative efficiencies of three natural Zn chelates [Zn-aminelignosulphonate (Zn-AML), Zn-polyhydroxyphenylcarboxylate (Zn-PHP) and Zn-S,S-ethylenediaminedisuccinate (Zn-S,S-EDDS)] applied to a crop textile flax (Linum ussitatisimum L.) at application rates of 0, 5 and 10 mg Zn kg−1. In the flax plant, the following parameters were determined: dry matter yield, soluble and total Zn concentrations in leaf and stem, chlorophyll, crude fibre, and tensile properties. For the different soil samples, the following parameters were determined: available Zn (DTPA-AB and Mehlich-3 extractable Zn), easily leachable Zn (BaCl2-extractable Zn), the distribution of Zn fractions, pH and redox potential. On the basis of the use of added Zn by flax, or Zn utilization, it would seem recommendable to apply Zn-S,S-EDDS at the low Zn rate in both soils. In contrast, adding the high Zn rate of this chelate to the weakly acidic soil produced an excessive Zn concentration in the plant, which caused a significant decrease in both dry matter yield and chlorophyll content. Furthermore, assessing available Zn with the DTPA-AB method proved the best way of estimating the level of excess Zn in flax plants. The soluble Zn concentration, which was established with 2-(N-morpholino)ethanesulfonic acid reagent (MES), of plant fresh and dry matter could be used as an alternative way of diagnosing the nutritional status of Zn in flax plants. In this experiment, the highest soil pHs were associated with the lowest redox potentials, which coincided with the smallest amounts of available Zn and water soluble Zn in soil, and the lowest levels of Zn uptake by flax plants

    Southern African Large Telescope Spectroscopy of BL Lacs for the CTA project

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    In the last two decades, very-high-energy gamma-ray astronomy has reached maturity: over 200 sources have been detected, both Galactic and extragalactic, by ground-based experiments. At present, Active Galactic Nuclei (AGN) make up about 40% of the more than 200 sources detected at very high energies with ground-based telescopes, the majority of which are blazars, i.e. their jets are closely aligned with the line of sight to Earth and three quarters of which are classified as high-frequency peaked BL Lac objects. One challenge to studies of the cosmological evolution of BL Lacs is the difficulty of obtaining redshifts from their nearly featureless, continuum-dominated spectra. It is expected that a significant fraction of the AGN to be detected with the future Cherenkov Telescope Array (CTA) observatory will have no spectroscopic redshifts, compromising the reliability of BL Lac population studies, particularly of their cosmic evolution. We started an effort in 2019 to measure the redshifts of a large fraction of the AGN that are likely to be detected with CTA, using the Southern African Large Telescope (SALT). In this contribution, we present two results from an on-going SALT program focused on the determination of BL Lac object redshifts that will be relevant for the CTA observatory

    A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

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    dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

    Molecular gated nanoporous anodic alumina for the detection of cocaine

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    [EN] We present herein the use of nanoporous anodic alumina (NAA) as a suitable support to implement molecular gates for sensing applications. In our design, a NAA support is loaded with a fluorescent reporter (rhodamine B) and functionalized with a short single-stranded DNA. Then pores are blocked by the subsequent hybridisation of a specific cocaine aptamer. The response of the gated material was studied in aqueous solution. In a typical experiment, the support was immersed in hybridisation buffer solution in the absence or presence of cocaine. At certain times, the release of rhodamine B from pore voids was measured by fluorescence spectroscopy. The capped NAA support showed poor cargo delivery, but presence of cocaine in the solution selectively induced rhodamine B release. By this simple procedure a limit of detection as low as 5 × 10−7 M was calculated for cocaine. The gated NAA was successfully applied to detect cocaine in saliva samples and the possible re-use of the nanostructures was assessed. Based on these results, we believe that NAA could be a suitable support to prepare optical gated probes with a synergic combination of the favourable features of selected gated sensing systems and NAA.We thank Projects MAT2015-64139-C4-1-R and TEC2015-71324-R (MINECO/FEDER), the Catalan Government (Project 2014 SGR 1344), the ICREA (ICREA2014 Academia Award) and the Generalitat Valenciana (Project PROMETEOII/2014/047) for support. We also thank to the Agencia Espanola del Medicamento y Productos Sanitarios for its concessions. A.R. thanks the UPV for her predoctoral fellowship. The authors also thank the Electron Microscopy Service at UPV for support.Ribes, À.; Xifre Perez, E.; Aznar, E.; SancenĂłn Galarza, F.; Pardo Vicente, MT.; Marsal, LF.; MartĂ­nez-Måñez, R. (2016). Molecular gated nanoporous anodic alumina for the detection of cocaine. Scientific Reports. 6. https://doi.org/10.1038/srep38649S386496Nadrah, P., PlaninĆĄek, O. & Gaberơček, M. Stimulus-responsive Mesoporous Silica Particles. J. Mater. Sci. 49, 481–495 (2014).Baeza, A., Colilla, M. & Vallet-RegĂ­, M. Advances in Mesoporous Silica Nanoparticles for Targeted Stimuli-Responsive Drug Delivery. Expert Opin. Drug Deliv. 12, 319–337 (2015).Karimi, M., Mirshekari, H., Aliakbari, M., Zangabad, P. S. & Hamblin, M. R. Smart Mesoporous Silica Nanoparticles for Controlled-Release Drug Delivery. Nanotech. Rev. 5, 195–207 (2016).Aznar, E. et al. Gated Materials for On-Command Release of Guest Molecules. Chem. Rev. 116, 561−718 (2016).SancenĂłn, F., Pascual, Ll., Oroval, M., Aznar, E. & MartĂ­nez-Måñez, R. Gated Silica Mesoporous Materials in Sensing Applications. Chemistry Open. 4, 418–437 (2015).Lu, C.-H., Willner, B. & Willner, I. DNA nanotechnology: From sensing and DNA machines to drug-delivery systems. ACSNano 7, 8320–8332 (2013).Klajn, R., Stoddart, J. F. & Grzybowski, B. A. Nanoparticles Functionalized With Reversible Molecular And Supramolecular Switches. Chem. Soc. Rev. 39, 2203–2237 (2010).Wei, R., Martin, T. G., Rant, U. & Dietz, H. DNA Origami Gatekeepers for Solid-State Nanopores. Angew. Chem. Int. Ed. 51, 4864 4867 (2012).Zhu, C. L., Lu, C. H., Song, X. Y., Yang, H. H. & Wang, X. R. Bioresponsive Controlled Release Using Mesoporous Silica Nanoparticles Capped with Aptamer-Based Molecular Gate. J. Am. Chem. Soc. 133, 1278–1281 (2011).Özalp, V. C., Pinto, A., Nikulina, E., Chulivin, A. & SchĂ€fer, T. In Situ Monitoring of DNA-Aptavalve Gating Function on Mesoporous Silica Nanoparticles. Part. Part. Sys. Charact. 31, 161–167 (2014).Choi, Y. L., Jaworski, J., Seo, M. L., Lee, S. J. & Jung, J. H. Controlled release using mesoporous silica nanoparticles functionalized with 18-crown-6 derivative. J. Mater. Chem. 21, 7882–7885 (2011).Zhang, Z., Wang, F., Balogh, D. & Willner, I. pH-controlled release of substrates from mesoporous SiO2 nanoparticles gated by metal ion-dependent DNAzymes. J. Mater. Chem. B. 2, 4449–4455 (2014).Fu, L. et al. Portable and Quantitative Monitoring of Heavy Metal Ions Using Dnazyme-Capped Mesoporous Silica Nanoparticles with a Glucometer Readout. J. Mater. Chem. B. 1, 6123–6128 (2013).DĂ­ez, P. et al. Toward the Design of Smart Delivery Systems Controlled by Integrated Enzyme-Based Biocomputing Ensembles. J. Am. Chem. Soc. 136, 9116–9123 (2014).Tang, D. et al. Low-Cost and Highly Sensitive lmmunosensing Platform for Aflatoxins Using One-Step Competitive Displacement Reaction Mode and Portable Glucometer-Based Detection. Anal. Chem. 86, 11451–11458 (2014).Hou, L., Zhu, C., Wu, X., Chen, G. & Tang, D. Bioresponsive Controlled Release from Mesoporous Silica Nanocontainers with Glucometer Readout. Chem. Commun. 50, 1441–1443 (2014).Chen, Z. et al. Stimulus-response mesoporous silica nanoparticle-based chemiluminescence biosensor for cocaine determination. Biosens. Bioelectro. 75, 8–14 (2016).Pascual, L. L. et al. Oligonucleotide-Capped Mesoporous Silica Nanoparticles as DNA-Responsive Dye Delivery Systems for Genomic DNA Detection. Chem. Commun. 51, 1414–1416 (2015).Qian, R., Ding, I. & Ju, H. Switchable Fluorescent Imaging of Intracellular Telomerase Activity Using Telomerase-Responsive Mesoporous Silica Nanoparticle. J. Am. Chem. Soc. 135, 13282–13285 (2013).Ren, K., Wu, J., Zhang, Y., Yan, F. & Ju, H. Proximity Hybridization Regulated DNA Biogate for Sensitive Electrochemical Immunoassay. Anal. Chem. 86, 7494–7499 (2014).Chen, Y., Santos, A., Wang, Y., Wang, C. & Losic, D. Biomimetic Nanoporous Anodic Alumina Distributed Bragg Reflectors in the Form of Films and Microsized Particles for Sensing Applications. ACS Appl Mater Interfaces. 7, 19816–19824 (2015).Aw, M. S., Bariana, M. & Losic, D. In Nanoporous Alumina. Fabrication, Structure, Properties and Applications (ed. Losic, D., Santos, A. ) 319–354 (Springer International Publishing, 2015).Urteaga, R. & Berli, C. L. In Nanoporous Alumina. Fabrication, Structure, Properties and Applications (ed. Losic, D., Santos, A. ) 249–269 (Springer International Publishing, 2015).Vojkuvka, L., Marsal, L. F., FerrĂ©-Borrull, J., Formentin, P. & PallarĂ©s, J. Self-Ordered Porous Alumina Membranes with Large Lattice Constant Fabricated by Hard Anodization. Superlattices Microstruct. 44, 577–582 (2008).De la Escosura-Muñiz, A. & Merkoçi, A. Nanochannels Preparation and Application in Biosensing. ACS Nano. 6, 7556–7583 (2012).Kumeria, T. et al. Nanoporous Anodic Alumina Rugate Filters for Sensing of Ionic Mercury: Toward Environmental Point-of-Analysis Systems. ACS Appl. Mater. Interfaces. 6, 12971−12978 (2014).Santos, A., Kumeria, T. & Losic, D. Nanoporous Anodic Alumina: A Versatile Platform for Optical Biosensors. Materials. 7, 4297–4320 (2014).FerrĂ©-Borrull, J., PallarĂšs, J., MacĂ­as, G. & Marsal, L. F. Nanostructural Engineering of Nanoporous Anodic Alumina for Biosensing Applications. Materials. 7, 5225–5253 (2014).Gong, D., Yadavalli, V., Paulose, M., Pishko, M. & Grimes, C. A. Controlled Molecular Release Using Nanoporous Alumina Capsules. Biomed Microdevices. 5, 75–80 (2003).Alvarez, S. D., Li, C.-P., Chiang, C. E., Schuller, I. K. & Sailor, M. J. A Label-Free Porous Alumina Interferometric Immunosensor. ACSNano. 3, 3301–3307 (2009).Krismastuti, F. S. H., Bayat, H., Voelcker, N. H. & Schönherr, H. Real Time Monitoring of Layer-by-Layer Polyelectrolyte Deposition and Bacterial Enzyme Detection in Nanoporous Anodized Aluminum Oxide Anal. Chem. 87, 3856–3863 (2015).Ma, D.-L. et al. A Luminescent Cocaine Detection Platform Using a Split G-Quadruplex-Selective Iridium (III) Complex and a Three-Way DNA Junction Architecture. ACS Appl. Mater. Interfaces. 7, 19060−19067 (2015).Kohli, P. et al. DNA-Functionalized Nanotube Membranes with Single-Base Mismatch Selectivity. Science 305, 984–986 (2004).Abelow, A. E. et al. Biomimetic glass nanopores employing aptamer gates responsive to a small molecule. Chem. Commun. 46, 7984–7986 (2010).Ma, D.-L., Chan, D. S.-H. & Leung, C.-H. Group 9 Organometallic Compounds for Therapeutic and Bioanalytical Applications. Acc. Chem. Res. 47, 3614–3631 (2014).Wanga, G., Zhua, Y., Chena, L. & Zhanga, X. Photoinduced electron transfer (PET) based label-free aptasensor for platelet-derived growth factor-BB and its logic gate application. Biosens. Bioelectron. 63, 552–557 (2015).Laptenko, O. et al. The p53 C Terminus Controls Site-Specific DNA Binding and Promotes Structural Changes within the Central DNA Binding Domain. Molec. Cell. 57, 1034–1046 (2015).McKeague, M. & DeRosa, M. C. Challenges and Opportunities for Small Molecule Aptamer Development. J. Nucleic Acids. 2012, 1–20 (2012).McKeague, M. et al. Analysis of In Vitro Aptamer Selection Parameters, J. Mol. Evol. 81, 150–161 (2015).Ellington, A. D. & Szostak, J. W. In vitro selection of RNA molecules that bind specific ligands. Nature. 346, 818–822 (1990).Wochner, A. et al. A DNA aptamer with high affinity and specificity for therapeutic anthracyclines. Anal Biochem. 373, 34–42 (2008).Song, K. M., Jeong, E., Jeon, W., Cho, M. & Ban, C. Aptasensor for ampicillin using gold nanoparticle based dual fluorescence-colorimetric methods. Anal. Bioanal. Chem. 402, 2153–2161 (2012).Özalp, V. C. & SchĂ€fer, T. Aptamer-Based Switchable Nanovalves for Stimuli-Responsive Drug Delivery. Chem. Eur. J. 17, 9893–9896 (2011).Stojanovic, M. N., de Prada, P. & Landry, D. W. Aptamer-Based Folding Fluorescent Sensor for Cocaine. J. Am. Chem Soc. 123, 4928–4931 (2001).Wen, Y. et al. DNA-based intelligent logic controlled release systems. Chem. Commun. 48, 8410–8412 (2012).Chen, L. et al. Programmable DNA switch for bioresponsive controlled release. J. Mater. Chem. 21, 13811–13816 (2011).Oroval, M. et al. An aptamer-gated silica mesoporous material for thrombin detection. Chem. Commun. 49, 5480–5482 (2013).Barroso, M., Gallardo, E. & Queiroz, J. A. Bioanalytical methods for the determination of cocaine and metabolites in human biological samples. Bioanalysis. 1, 977–1000 (2009).Phan, H. M., Yoshizuka, K., Murry, D. J. & Perry, P. J. Drug testing in the workplace. Pharmacotherapy. 32, 649–656 (2012).Kidwell, D. A., Blanco, M. A. & P. Smith, F. P. Cocaine detection in a university population by hair analysis and skin swab testing. Forensic Sci. Int. 84, 75–86 (1997).Swensen, J. S. et al. Continuous, Real-Time Monitoring of Cocaine in Undiluted Blood Serum via a Microfluidic, Electrochemical Aptamer-Based Sensor. J. Am. Chem. Soc. 131, 4262–4266 (2009).Cai, Q. et al. Determination of cocaine on banknotes through an aptamer-based electrochemiluminescence biosensor. Anal. Bioanal. Chem. 400, 289–294 (2011).Zou, R. et al. Highly specific triple-fragment aptamer for optical detection of cocaine. RSC Adv. 2, 4636–4638 (2012).Qiu, L. et al. A novel label-free fluorescence aptamer-based sensor method for cocaine detection based on isothermal circular strand-displacement amplification and graphene oxide absorption. New J. Chem. 37, 3998 (2013).Marsal, L. F., Vojkuvka, L., Formentin, P., PallarĂ©s, J. & FerrĂ©-Borrull, J. Fabrication and Optical Characterization of Nanoporous Alumina Films Annealed at Different Temperatures. Optical Mater. 31, 860–864 (2009).Bosker, W. M. & Huestis, M. A. Oral Fluid Testing for Drugs of Abuse. Clinical Chem. 55, 1910–1931 (2009).Kolbrich, E. A. et al. CozartÂź RapiScan Oral Fluid Drug Testing System: An Evaluation of Sensitivity, Specificity, and Efficiency for Cocaine Detection Compared with ELISA and GC-MS Following Controlled Cocaine Administration. J. Anal Toxicol. 27, 407–411 (2003).Cooper, G., Wilson, L., Reid, C., Main, L. & Hand, C. Evaluation of the CozartÂź RapiScan drug test system for opiates and cocaine in oral fluid. Forensic Sci. Int. 150, 239–243 (2005).Chang, Y. H. et al. Cocaine detection by a mid-infrared waveguide integrated with a microfluidic chip. Lab Chip. 12, 3020–3023 (2012).Walczak, R. et al. Toward Portable Instrumentation for Quantitative Cocaine Detection with Lab-on-a-Paper and Hybrid Optical Readout. Procedia Chem. 1, 999–1002 (2009).Qiu, L. et al. A novel label-free fluorescence aptamer-based sensor method for cocaine detection based on isothermal circular strand-displacement amplification and graphene oxide absorption. New J. Chem. 37, 3998–4003 (2013)
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