Histologia da embriogênese somática induzida em embriões de sementes maduras de Urochloa brizantha apomítica

O objetivo deste trabalho foi descrever o processo de embriogênese somática em Urochloa brizantha cv. Marandu (Syn. Brachiaria brizantha cv. Marandu) e fornecer subsídios para o aprimoramento dos métodos de cultura de tecidos e transformação genética. Calos embriogênicos foram obtidos por indução em embriões isolados de sementes maduras, e cultivados in vitro, em meio de cultura que continha ácido 2,4‑diclorofenoxiacético, 6‑benzilaminopurina e caseína hidrolisada. Plântulas foram regeneradas a partir dos calos embriogênicos, na presença de ácido naftalenoacético e cinetina. Esse processo foi descrito morfologicamente por observações em microscopia de luz de secções seriadas semifinas de tecidos fixados, ao longo do processo de regeneração, em FAA [formaldeído (40%): ácido acético glacial: etanol (50%), a 5:5:90 v/v/v]. Os embriões das sementes de U. brizantha cv. Marandu não têm epiblasto e são classificados como do tipo panicoide. Nas condições estabelecidas de cultura in vitro, calos embriogênicos e embriões somáticos de U. brizantha cv. Marandu, desenvolvem-se a partir de células meristemáticas do escutelo

ECGdeli - An open source ECG delineation toolbox for MATLAB

The electrocardiogram (ECG) is a standard cost-efficient and non-invasive tool for the early detection of various cardiac diseases. Quantifying different timing and amplitude features of and in between the single ECG waveforms can reveal important information about the underlying (dys-)function of the heart. Determining these features requires the detection of fiducial points that mark the on- and offset as well as the peak of each ECG waveform (P wave, QRS complex, T wave). Manually setting these points is time-consuming and requires a physician’s expert knowledge. Therefore, the highly modular ECGdeli toolbox for MATLAB was developed, which is capable of filtering clinically recorded 12-lead ECG signals and detecting the fiducial points, also called delineation. It is one of the few open toolboxes offering ECG delineation for P waves, T Waves and QRS complexes. The algorithms provided were evaluated with the QT database, an ECG database comprising 105 signals with fiducial points annotated by clinicians. The median difference between the fiducial points set by the boundary detection algorithm and the clinical annotations serving as a ground truth is less than 4 samples (16 ms) for the P wave and the QRS complex markers. The T wave onset, peak and offset were detected with a median difference of 5, 2 and 7 samples, respectively. Results were compared to two free algorithms available on PhysioNet. Our results show that ECGdeli can reliably detect P waves, QRS complexes and T waves. Thus, it can contribute to diagnose specific cardiac diseases by analyzing the ECG signal. As ECGdeli is published under GNU GPLv3 and thanks to its modularity, it can be used to extend existing algorithms or as a benchmark for new algorithms

Sequence of Potentials Interpolating between the U(5) and E(5) Symmetries

It is proved that the potentials of the form $\beta^{2n}$ (with $n$ being integer) provide a ``bridge'' between the U(5) symmetry of the Bohr Hamiltonian with a harmonic oscillator potential (occuring for $n=1$) and the E(5) model of Iachello (Bohr Hamiltonian with an infinite well potential, materialized for infinite $n$). Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are given for the potentials $\beta^4$, $\beta^6$, $\beta^8$, corresponding to $R_4=E(4)/E(2)$ ratios of 2.093, 2.135, 2.157 respectively, compared to the $R_4$ ratios 2.000 of U(5) and 2.199 of E(5). Hints about nuclei showing this behaviour, as well as about potentials ``bridging'' the E(5) symmetry with O(6) are briefly discussed. A note about the appearance of Bessel functions in the framework of E(n) symmetries is given as a by-product.Comment: LaTeX, 17 pages, 9 postscript figure

Determinación del grado de fisuración en prismas de hormigón utilizando microscopía UV

En este trabajo se evalúa la relación existente entre la expansión de prismas de hormigón confeccionados según norma IRAM 1700-97, luego de cumplido cinco años de ensayo, y su grado de microfisuramiento. Los prismas fueron realizados con agregados basálticos provenientes de las principales canteras de la región mesopotámica. Los estudios se realizaron sobre secciones delgadas impregnadas con resina epoxi fluorescente y se determinó el valor de densidad de fisuras y área fisurada para el total de la superficie de cada sección mediante procesamiento informático. La expansión se relaciona mejor con los valores de área fisurada que con los valores de densidad de fisuras. Además, el incremento del número de imágenes analizadas disminuyó el desvío estándar de los valores de área fisurada.In this work relationship between expansion in concrete prisms (IRAM 1700-97), after five years of testing, and their degree of cracking is evaluated. Prisms were made with basaltic aggregates from the main quarries in the Mesopotamia region. Studies were performed on thin sections impregnated with fluorescent epoxy resin and cracks density and area of microcracks values were determined in the total surface of each section though computational processing. Expansion is better related with the cracked area than cracks density values. In addition, the increment in the number of images analyzed decreased the standard deviation of the cracked area values.Facultad de Ingeniería (FI

Development of multilayer Hydroxyapatite - Ag/TiN-Ti coatings deposited by radio frequency magnetron sputtering with potential application in the biomedical field

"NOTICE: this is the author's version of a work that was accepted for publication in Surface and Coatings Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Surface and Coatings Technology, VOL 377, (2019) DOI 10.1016/j.surfcoat.2019.06.097"[EN] The use of composite coatings is emerging as a great alternative to conventional coatings, allowing the combination of different superficial properties that are widely desired in surgical implants, such as osteointegration and bactericidal character, and cannot be provided by one material alone. In the present investigation the effect of the incorporation of a TiN-Ti intermediate bilayer on the chemical composition, structure, morphology, roughness, residual stresses and adhesion of a multi-layer Hydroxyapatite (HA)-Ag coating deposited on Ti-6Al-4V by magnetron sputtering was evaluated. Additionally, the cytotoxicity of the developed system was evaluated by in vitro tests. According to the results obtained, a decrease in the Ca/P ratio from 1.85 to 1.74 was obtained through the deposition of an HA-Ag system on the intermediate bilayer, and the crystallinity of the developed coating was favored. The multi-layer structure was effectively observed by field emission scanning electron microscopy, where it was possible to identify each of the HA, Ag, TiN and Ti layers. Meanwhile, an increase of 7% in crystallite size, a decrease of 36% in residual stresses and an increase of 32% in adhesion were registered for this composite coating compared to the free intermediate bilayer system. Finally, biological evaluation allowed the non-cytotoxic character of the deposited coatings to be confirmed.We thank the University of Antioquia, the Centro de Investigation, Innovation y Desarrollo de materiales (CIDEMAT) group, the Departamento Administrativo de Ciencia, Tecnologia e Innovation (COLCIENCIAS) for financing the Project 15-1696, the scholarship program of Enlazamundos, PR and JLGR acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-1-R (AEI/FEDER, UE) (including the FEDER financial support). CIBER-BBN is an initiative funded by the VI National R&D&I Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Institute de Salud Carlos III with assistance from the European Regional Development Fund.Lenis, J.; Bejarano, G.; Rico Tortosa, PM.; Gómez Ribelles, JL.; Bolívar, F. (2019). Development of multilayer Hydroxyapatite - Ag/TiN-Ti coatings deposited by radio frequency magnetron sputtering with potential application in the biomedical field. Surface and Coatings Technology. 377:1-9. https://doi.org/10.1016/j.surfcoat.2019.06.097S19377Melero, H., Fernández, J., & Guilemany Casadamon, J. M. (2011). Recubrimientos bioactivos: Hidroxiapatita y titania. Biomecánica, 19(1). doi:10.5821/sibb.v19i1.1814Ozeki, K., Yuhta, T., Fukui, Y., & Aoki, H. (2002). Phase composition of sputtered films from a hydroxyapatite target. Surface and Coatings Technology, 160(1), 54-61. doi:10.1016/s0257-8972(02)00363-8Nelea, V., Morosanu, C., Iliescu, M., & Mihailescu, I. N. (2003). Microstructure and mechanical properties of hydroxyapatite thin films grown by RF magnetron sputtering. Surface and Coatings Technology, 173(2-3), 315-322. doi:10.1016/s0257-8972(03)00729-1Mohseni, E., Zalnezhad, E., Bushroa, A. R., Abdel Magid Hamouda, Goh, B. T., & Yoon, G. H. (2015). Ti/TiN/HA coating on Ti–6Al–4V for biomedical applications. Ceramics International, 41(10), 14447-14457. doi:10.1016/j.ceramint.2015.07.081Nelea, V., Morosanu, C., Bercu, M., & Mihailescu, I. N. (2007). Interfacial titanium oxide between hydroxyapatite and TiAlFe substrate. Journal of Materials Science: Materials in Medicine, 18(12), 2347-2354. doi:10.1007/s10856-007-3135-1M.S. Tkachev, E.S. Melnikov, M.A. Surmeneva, A.A. Sharonova, R.A. Surmenev, O.S. Korneva, I.A. Shulepov, K. Loza, M. Epple, Adhesion properties of a three-layer system based on RF-magnetron sputter deposited calcium-phosphate coating and silver nanoparticles, Proc. - 2016 11th Int. Forum Strateg. Technol. IFOST 2016. (2017) 88–90. doi:https://doi.org/10.1109/IFOST.2016.7884197.E. Mohseni, E. Zalnezhad, a. R. Bushroa, Comparative investigation on the adhesion of hydroxyapatite coating on Ti-6Al-4V implant: A review paper, Int. J. Adhes. Adhes. 48 (2014) 238–257. doi:https://doi.org/10.1016/j.ijadhadh.2013.09.030.Sargeant, A., & Goswami, T. (2007). Hip implants – Paper VI – Ion concentrations. Materials & Design, 28(1), 155-171. doi:10.1016/j.matdes.2005.05.018Qi, J., Yang, Y., Zhou, M., Chen, Z., & Chen, K. (2019). Effect of transition layer on the performance of hydroxyapatite/titanium nitride coating developed on Ti-6Al-4V alloy by magnetron sputtering. Ceramics International, 45(4), 4863-4869. doi:10.1016/j.ceramint.2018.11.183Ghasemi, S., Shanaghi, A., & Chu, P. K. (2017). Nano mechanical and wear properties of multi-layer Ti/TiN coatings deposited on Al 7075 by high-vacuum magnetron sputtering. Thin Solid Films, 638, 96-104. doi:10.1016/j.tsf.2017.07.049Thian, E. S., Huang, J., Barber, Z. H., Best, S. M., & Bonfield, W. (2011). Surface modification of magnetron-sputtered hydroxyapatite thin films via silicon substitution for orthopaedic and dental applications. Surface and Coatings Technology, 205(11), 3472-3477. doi:10.1016/j.surfcoat.2010.12.012Vladescu, A., Birlik, I., Braic, V., Toparli, M., Celik, E., & Ak Azem, F. (2014). Enhancement of the mechanical properties of hydroxyapatite by SiC addition. Journal of the Mechanical Behavior of Biomedical Materials, 40, 362-368. doi:10.1016/j.jmbbm.2014.08.025Azem, F. A., Kiss, A., Birlik, I., Braic, V., Luculescu, C., & Vladescu, A. (2014). The corrosion and bioactivity behavior of SiC doped hydroxyapatite for dental applications. Ceramics International, 40(10), 15881-15887. doi:10.1016/j.ceramint.2014.07.116Ciobanu, C. S., Iconaru, S. L., Le Coustumer, P., Constantin, L. V., & Predoi, D. (2012). Antibacterial activity of silver-doped hydroxyapatite nanoparticles against gram-positive and gram-negative bacteria. Nanoscale Research Letters, 7(1). doi:10.1186/1556-276x-7-324Peetsch, A., Greulich, C., Braun, D., Stroetges, C., Rehage, H., Siebers, B., … Epple, M. (2013). Silver-doped calcium phosphate nanoparticles: Synthesis, characterization, and toxic effects toward mammalian and prokaryotic cells. Colloids and Surfaces B: Biointerfaces, 102, 724-729. doi:10.1016/j.colsurfb.2012.09.040A. Quirama, A.M. Echavarría, J.M. Meza, J. Osorio, G. Bejarano G, Improvement of the mechanical behavior of the calcium phosphate coatings deposited onto Ti6Al4V alloy using an intermediate TiN/TiO2 bilayer, Vacuum. 146 (2017) 22–30. doi:https://doi.org/10.1016/j.vacuum.2017.09.024.Lenis, J. A., Hurtado, F. M., Gómez, M. A., & Bolívar, F. J. (2019). Effect of thermal treatment on structure, phase and mechanical properties of hydroxyapatite thin films grown by RF magnetron sputtering. Thin Solid Films, 669, 571-578. doi:10.1016/j.tsf.2018.11.045Sofronia, A. M., Baies, R., Anghel, E. M., Marinescu, C. A., & Tanasescu, S. (2014). Thermal and structural characterization of synthetic and natural nanocrystalline hydroxyapatite. Materials Science and Engineering: C, 43, 153-163. doi:10.1016/j.msec.2014.07.023Shiri, S., Ashtijoo, P., Odeshi, A., & Yang, Q. (2016). Evaluation of Stoney equation for determining the internal stress of DLC thin films using an optical profiler. Surface and Coatings Technology, 308, 98-100. doi:10.1016/j.surfcoat.2016.07.098Barry, J. N., Cowley, A., McNally, P. J., & Dowling, D. P. (2013). Influence of substrate metal alloy type on the properties of hydroxyapatite coatings deposited using a novel ambient temperature deposition technique. Journal of Biomedical Materials Research Part A, 102(3), 871-879. doi:10.1002/jbm.a.34755Constable, C. P., Yarwood, J., & Münz, W.-D. (1999). Raman microscopic studies of PVD hard coatings. Surface and Coatings Technology, 116-119, 155-159. doi:10.1016/s0257-8972(99)00072-9Cuscó, R., Guitián, F., Aza, S. d., & Artús, L. (1998). Differentiation between hydroxyapatite and β-tricalcium phosphate by means of μ-Raman spectroscopy. Journal of the European Ceramic Society, 18(9), 1301-1305. doi:10.1016/s0955-2219(98)00057-0Ivanova, A. A., Surmeneva, M. A., Grubova, I. Y., Sharonova, A. A., Pichugin, V. F., Chaikina, M. V., … Surmenev, R. A. (2013). Influence of the substrate bias on the stoichiometry and structure of RF-magnetron sputter-deposited silver-containing calcium phosphate coatings. Materialwissenschaft und Werkstofftechnik, 44(2-3), 218-225. doi:10.1002/mawe.201300101Yonggang, Y., Wolke, J. G. C., Yubao, L., & Jansen, J. A. (2007). The influence of discharge power and heat treatment on calcium phosphate coatings prepared by RF magnetron sputtering deposition. Journal of Materials Science: Materials in Medicine, 18(6), 1061-1069. doi:10.1007/s10856-007-0119-0Xin, R., Leng, Y., Chen, J., & Zhang, Q. (2005). A comparative study of calcium phosphate formation on bioceramics in vitro and in vivo. Biomaterials, 26(33), 6477-6486. doi:10.1016/j.biomaterials.2005.04.028Surmeneva, M. A., Tyurin, A. I., Mukhametkaliyev, T. M., Pirozhkova, T. S., Shuvarin, I. A., Syrtanov, M. S., & Surmenev, R. A. (2015). Enhancement of the mechanical properties of AZ31 magnesium alloy via nanostructured hydroxyapatite thin films fabricated via radio-frequency magnetron sputtering. Journal of the Mechanical Behavior of Biomedical Materials, 46, 127-136. doi:10.1016/j.jmbbm.2015.02.025M.A. Surmeneva, M. V. Chaikina, V.I. Zaikovskiy, V.F. Pichugin, V. Buck, O. Prymak, M. Epple, R. a. Surmenev, The structure of an rf-magnetron sputter-deposited silicate-containinghydroxyapatite-based coating investigated by high-resolution techniques, Surf. Coatings Technol. 218 (2013) 39–46. doi:https://doi.org/10.1016/j.surfcoat.2012.12.023.A. Ivanova, M.A. Surmeneva, A.I. Tyurin, T.S. Pirozhkova, I.A. Shuvarin, O. Prymak, M. Epple, M. V Chaikina, R.A. Surmenev, Applied Surface Science Fabrication and physico-mechanical properties of thin magnetron sputter deposited silver-containing hydroxyapatite films, 360 (2016) 929–935.Ding, S.-J., Ju, C.-P., & Lin, J.-H. C. (1999). Characterization of hydroxyapatite and titanium coatings sputtered on Ti-6Al-4V substrate. Journal of Biomedical Materials Research, 44(3), 266-279. doi:10.1002/(sici)1097-4636(19990305)44:33.0.co;2-4A.R.A. Sagari, Ca-P-O thin film preparation, modification and characterisation, Ph.D thesis, University of Jyväskylä, 2011. https://jyx.jyu.fi/bitstream/handle/123456789/37195/Arcot_Rajashekar-Ananda-2011.pdf?sequence=1.Paital, S. R., & Dahotre, N. B. (2009). Calcium phosphate coatings for bio-implant applications: Materials, performance factors, and methodologies. Materials Science and Engineering: R: Reports, 66(1-3), 1-70. doi:10.1016/j.mser.2009.05.001Deligianni, D. (2001). Effect of surface roughness of the titanium alloy Ti–6Al–4V on human bone marrow cell response and on protein adsorption. Biomaterials, 22(11), 1241-1251. doi:10.1016/s0142-9612(00)00274-xEchavarría, A. M., Rico, P., Gómez Ribelles, J. L., Pacha-Olivenza, M. A., Fernández-Calderón, M.-C., & Bejarano-G, G. (2017). Development of a Ta/TaN/TaNx(Ag)y/TaN nanocomposite coating system and bio-response study for biomedical applications. Vacuum, 145, 55-67. doi:10.1016/j.vacuum.2017.08.020García, C. G., Ferrus, L. L., Moratal, D., Pradas, M. M., & Sánchez, M. S. (2009). Poly(L-lactide) Substrates with Tailored Surface Chemistry by Plasma Copolymerisation of Acrylic Monomers. Plasma Processes and Polymers, 6(3), 190-198. doi:10.1002/ppap.200800112Perdok, W. G., Christoffersen, J., & Arends, J. (1987). The thermal lattice expansion of calcium hydroxyapatite. Journal of Crystal Growth, 80(1), 149-154. doi:10.1016/0022-0248(87)90534-3Evans, A. G., Crumley, G. B., & Demaray, R. E. (1983). On the mechanical behavior of brittle coatings and layers. Oxidation of Metals, 20(5-6), 193-216. doi:10.1007/bf00656841ASTM C1624-05, Standard Test Method for Adhesion Strength and Mechanical Failure Modes of, Astm. 05 (2015) 1–29. doi:https://doi.org/10.1520/C1624-05R15.Scope.Yang, Y. ., & Chang, E. (2001). Influence of residual stress on bonding strength and fracture of plasma-sprayed hydroxyapatite coatings on Ti–6Al–4V substrate. Biomaterials, 22(13), 1827-1836. doi:10.1016/s0142-9612(00)00364-1Lenis, J. A., Toro, L. J., & Bolívar, F. J. (2019). Multi-layer bactericidal silver - calcium phosphate coatings obtained by RF magnetron sputtering. Surface and Coatings Technology, 367, 203-211. doi:10.1016/j.surfcoat.2019.03.03

Determinación del grado de fisuración en prismas de hormigón utilizando microscopía UV

En este trabajo se evalúa la relación existente entre la expansión de prismas de hormigón confeccionados según norma IRAM 1700-97, luego de cumplido cinco años de ensayo, y su grado de microfisuramiento. Los prismas fueron realizados con agregados basálticos provenientes de las principales canteras de la región mesopotámica. Los estudios se realizaron sobre secciones delgadas impregnadas con resina epoxi fluorescente y se determinó el valor de densidad de fisuras y área fisurada para el total de la superficie de cada sección mediante procesamiento informático. La expansión se relaciona mejor con los valores de área fisurada que con los valores de densidad de fisuras. Además, el incremento del número de imágenes analizadas disminuyó el desvío estándar de los valores de área fisurada.In this work relationship between expansion in concrete prisms (IRAM 1700-97), after five years of testing, and their degree of cracking is evaluated. Prisms were made with basaltic aggregates from the main quarries in the Mesopotamia region. Studies were performed on thin sections impregnated with fluorescent epoxy resin and cracks density and area of microcracks values were determined in the total surface of each section though computational processing. Expansion is better related with the cracked area than cracks density values. In addition, the increment in the number of images analyzed decreased the standard deviation of the cracked area values.Facultad de Ingeniería (FI

Reproducción inducida de la liseta Leporinus muyscorum (Steindachner, 1902) con extracto pituitario de carpa (EPC).

La Liseta Leporinus muyscorum (Steindachner 1902) presenta características de importancia para la piscicultura, dentro de las cuales se destacan su adaptación a dietas artificiales y la calidad de su carne. No se reproduce en confinamiento, siendo necesaria su reproducción inducida con sustancias hormonales. Con reproductores capturados en el río Sinú en noviembre de 1999 y luego mantenidos en confinamiento hasta mayo de 2000 en el Centro Piscícola San Gabriel de la Corporación de los Valles del Sinú y San Jorge (CVS, Córdoba, Colombia), se logró su reproducción inducida con extracto pituitario de carpa (EPC) por primera vez en el país. Se utilizaron cuatro dosificaciones 1, 3, 5, 7 mg EPC/Kg. La dosis se dividió en dos aplicaciones en las hembras, correspondiendo 10 y 90% de la dosis total, con un intervalo de 12 horas. En los machos se aplicó una sola dosis única, equivalente al 80% de la dosis total de las hembras