Quenching a steel plate by water-impinging jets and different simultaneous flow rates

Regarding the great importance of fast cooling in steel industry for the production processes, a deep understanding of heat transfer and fluid dynamics must be held. A steel plate is heated up until a maximum temperature of 700 ⁰C to be then cooled down seconds later by a configuration of multiple impinging water jets. Different flow rates are used simultaneously by different adjacent jets to perform quenching over the sample, so different hardness is obtained in the material over a small area. Temperature drop in time is measured and monitored by embedded thermocouples and LabVIEW program. To achieve greater understanding of the quenching performance with different flow rates, several parameters are selected to be varied in order to achieve the best working conditions. Jet diameter takes values between 4 and 10 mm, initial temperature of quenching varies from 400 to 700 ⁰C, subcooling temperature is tested for 65 and 75 K, and jet velocity varies between 1.9 and 3.9 m/s. The result of total number of 9 experiments shown that variation of jet diameter does not influence substantially on the cooling rate if flow rate is kept constant. High initial quenching temperature (600-700 ⁰C) led to slightly higher cooling rate in the stagnation region of water jets. The peak value of heat transfer rate in the upwash flow zone was more highlighted for initial quenching temperature 600⁰C and below it. Higher values of subcooling and jet velocity produce better cooling rates. The result shown higher jet velocity at one column of water jets changes position of upwash flow slightly toward the adjacent column of jets with lower jet velocity. In general, the result shown that all the studied parameters did not have negative effect on obtaining various cooling rates over the steel plate.<br /

A New Environmentally-Friendly Colorimetric Probe for Formaldehyde Gas Detection under Real Conditions

[EN] A new environmentally-friendly, simple, selective and sensitive probe for detecting formaldehyde, based on naturally-occurring compounds, through either colorimetric or fluorescence changes, is described. The probe is able to detect formaldehyde in both solution and the gas phase with limits of detection of 0.24 mM and 0.7 ppm, respectively. The probe has been tested to study formaldehyde emission in contaminated real atmospheres. The supported probe is easy to use and to dispose, and is safe and suitable as an individual chemodosimeter.This research was funded by the Spanish Government (projects MAT2015-64139-C4-4-R and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047).Martínez-Aquino, C.; Costero, AM.; Gil Grau, S.; Gaviña, P. (2018). A New Environmentally-Friendly Colorimetric Probe for Formaldehyde Gas Detection under Real Conditions. Molecules. 23(10). https://doi.org/10.3390/molecules23102646S2310https://mcgroup.co.uk/news/20140627/formaldehyde-production-exceed-52-mln-tonnes.htmlGoris, J. A., Ang, S., & Navarro, C. (1998). Laboratory Safety: Minimizing the Toxic Effects of Formaldehyde. Laboratory Medicine, 29(1), 39-43. doi:10.1093/labmed/29.1.39Luo, W., Li, H., Zhang, Y., & Ang, C. Y. . (2001). Determination of formaldehyde in blood plasma by high-performance liquid chromatography with fluorescence detection. Journal of Chromatography B: Biomedical Sciences and Applications, 753(2), 253-257. doi:10.1016/s0378-4347(00)00552-1ROCHA, F., COELHO, L., LOPES, M., CARVALHO, L., FRACASSIDASILVA, J., DOLAGO, C., & GUTZ, I. (2008). Environmental formaldehyde analysis by active diffusive sampling with a bundle of polypropylene porous capillaries followed by capillary zone electrophoretic separation and contactless conductivity detection. Talanta, 76(2), 271-275. doi:10.1016/j.talanta.2008.02.037Korpan, Y. I., Gonchar, M. V., Sibirny, A. A., Martelet, C., El’skaya, A. V., Gibson, T. D., & Soldatkin, A. P. (2000). Development of highly selective and stable potentiometric sensors for formaldehyde determination. Biosensors and Bioelectronics, 15(1-2), 77-83. doi:10.1016/s0956-5663(00)00054-3Dong, S., & Dasgupta, P. K. (1986). Solubility of gaseous formaldehyde in liquid water and generation of trace standard gaseous formaldehyde. Environmental Science & Technology, 20(6), 637-640. doi:10.1021/es00148a016MITSUBAYASHI, K., NISHIO, G., SAWAI, M., SAITO, T., KUDO, H., SAITO, H., … MARTY, J. (2008). A bio-sniffer stick with FALDH (formaldehyde dehydrogenase) for convenient analysis of gaseous formaldehyde. Sensors and Actuators B: Chemical, 130(1), 32-37. doi:10.1016/j.snb.2007.07.086DEMKIV, O., SMUTOK, O., PARYZHAK, S., GAYDA, G., SULTANOV, Y., GUSCHIN, D., … GONCHAR, M. (2008). Reagentless amperometric formaldehyde-selective biosensors based on the recombinant yeast formaldehyde dehydrogenase. Talanta, 76(4), 837-846. doi:10.1016/j.talanta.2008.04.040Dennison, M. J., Hall, J. M., & Turner, A. P. F. (1996). Direct monitoring of formaldehyde vapour and detection of ethanol vapour using dehydrogenase-based biosensors. The Analyst, 121(12), 1769. doi:10.1039/an9962101769Wang, X., Si, Y., Mao, X., Li, Y., Yu, J., Wang, H., & Ding, B. (2013). Colorimetric sensor strips for formaldehyde assay utilizing fluoral-p decorated polyacrylonitrile nanofibrous membranes. The Analyst, 138(17), 5129. doi:10.1039/c3an00812fPinheiro, H. L. ., de Andrade, M. V., de Paula Pereira, P. A., & de Andrade, J. B. (2004). Spectrofluorimetric determination of formaldehyde in air after collection onto silica cartridges coated with Fluoral P. Microchemical Journal, 78(1), 15-20. doi:10.1016/j.microc.2004.02.017Antwi-Boampong, S., Peng, J. S., Carlan, J., & BelBruno, J. J. (2014). A Molecularly Imprinted Fluoral-P/Polyaniline Double Layer Sensor System for Selective Sensing of Formaldehyde. IEEE Sensors Journal, 14(5), 1490-1498. doi:10.1109/jsen.2014.2298872Xu, Z., Chen, J., Hu, L.-L., Tan, Y., Liu, S.-H., & Yin, J. (2017). Recent advances in formaldehyde-responsive fluorescent probes. Chinese Chemical Letters, 28(10), 1935-1942. doi:10.1016/j.cclet.2017.07.018Brewer, T. F., & Chang, C. J. (2015). An Aza-Cope Reactivity-Based Fluorescent Probe for Imaging Formaldehyde in Living Cells. Journal of the American Chemical Society, 137(34), 10886-10889. doi:10.1021/jacs.5b05340Roth, A., Li, H., Anorma, C., & Chan, J. (2015). A Reaction-Based Fluorescent Probe for Imaging of Formaldehyde in Living Cells. Journal of the American Chemical Society, 137(34), 10890-10893. doi:10.1021/jacs.5b05339Li, J.-B., Wang, Q.-Q., Yuan, L., Wu, Y.-X., Hu, X.-X., Zhang, X.-B., & Tan, W. (2016). A two-photon fluorescent probe for bio-imaging of formaldehyde in living cells and tissues. The Analyst, 141(11), 3395-3402. doi:10.1039/c6an00473cTang, Y., Kong, X., Xu, A., Dong, B., & Lin, W. (2016). Development of a Two-Photon Fluorescent Probe for Imaging of Endogenous Formaldehyde in Living Tissues. Angewandte Chemie International Edition, 55(10), 3356-3359. doi:10.1002/anie.201510373He, L., Yang, X., Liu, Y., Kong, X., & Lin, W. (2016). A ratiometric fluorescent formaldehyde probe for bioimaging applications. Chemical Communications, 52(21), 4029-4032. doi:10.1039/c5cc09796gSingha, S., Jun, Y. W., Bae, J., & Ahn, K. H. (2017). Ratiometric Imaging of Tissue by Two-Photon Microscopy: Observation of a High Level of Formaldehyde around Mouse Intestinal Crypts. Analytical Chemistry, 89(6), 3724-3731. doi:10.1021/acs.analchem.7b00044Song, H., Rajendiran, S., Kim, N., Jeong, S. K., Koo, E., Park, G., … Yoon, S. (2012). A tailor designed fluorescent ‘turn-on’ sensor of formaldehyde based on the BODIPY motif. Tetrahedron Letters, 53(37), 4913-4916. doi:10.1016/j.tetlet.2012.06.117Zhou, Y., Yan, J., Zhang, N., Li, D., Xiao, S., & Zheng, K. (2018). A ratiometric fluorescent probe for formaldehyde in aqueous solution, serum and air using aza-cope reaction. Sensors and Actuators B: Chemical, 258, 156-162. doi:10.1016/j.snb.2017.11.043Chaiendoo, K., Sooksin, S., Kulchat, S., Promarak, V., Tuntulani, T., & Ngeontae, W. (2018). A new formaldehyde sensor from silver nanoclusters modified Tollens’ reagent. Food Chemistry, 255, 41-48. doi:10.1016/j.foodchem.2018.02.030Fauzia, V., Nurlely, Imawan, C., Narayani, N. M. M. S., & Putri, A. E. (2018). A localized surface plasmon resonance enhanced dye-based biosensor for formaldehyde detection. Sensors and Actuators B: Chemical, 257, 1128-1133. doi:10.1016/j.snb.2017.11.031El Sayed, S., Pascual, L., Licchelli, M., Martínez-Máñez, R., Gil, S., Costero, A. M., & Sancenón, F. (2016). Chromogenic Detection of Aqueous Formaldehyde Using Functionalized Silica Nanoparticles. ACS Applied Materials & Interfaces, 8(23), 14318-14322. doi:10.1021/acsami.6b03224Li, Z., Xue, Z., Wu, Z., Han, J., & Han, S. (2011). Chromo-fluorogenic detection of aldehydes with a rhodamine based sensor featuring an intramolecular deoxylactam. Organic & Biomolecular Chemistry, 9(22), 7652. doi:10.1039/c1ob06448gGuglielmino, M., Allouch, A., Serra, C. A., & Calvé, S. L. (2017). Development of microfluidic analytical method for on-line gaseous Formaldehyde detection. Sensors and Actuators B: Chemical, 243, 963-970. doi:10.1016/j.snb.2016.11.093Xia, H., Hu, J., Tang, J., Xu, K., Hou, X., & Wu, P. (2016). A RGB-Type Quantum Dot-based Sensor Array for Sensitive Visual Detection of Trace Formaldehyde in Air. Scientific Reports, 6(1). doi:10.1038/srep36794Feng, L., Musto, C. J., & Suslick, K. S. (2010). A Simple and Highly Sensitive Colorimetric Detection Method for Gaseous Formaldehyde. Journal of the American Chemical Society, 132(12), 4046-4047. doi:10.1021/ja910366pGuo, X.-L., Chen, Y., Jiang, H.-L., Qiu, X.-B., & Yu, D.-L. (2018). Smartphone-Based Microfluidic Colorimetric Sensor for Gaseous Formaldehyde Determination with High Sensitivity and Selectivity. Sensors, 18(9), 3141. doi:10.3390/s18093141He, L., Yang, X., Ren, M., Kong, X., Liu, Y., & Lin, W. (2016). An ultra-fast illuminating fluorescent probe for monitoring formaldehyde in living cells, shiitake mushrooms, and indoors. Chemical Communications, 52(61), 9582-9585. doi:10.1039/c6cc04254fGangopadhyay, A., Maiti, K., Ali, S. S., Pramanik, A. K., Guria, U. N., Samanta, S. K., … Mahapatra, A. K. (2018). A PET based fluorescent chemosensor with real time application in monitoring formaldehyde emissions from plywood. Analytical Methods, 10(24), 2888-2894. doi:10.1039/c8ay00514aLin, Q., Fan, Y.-Q., Gong, G.-F., Mao, P.-P., Wang, J., Guan, X.-W., … Wei, T.-B. (2018). Ultrasensitive Detection of Formaldehyde in Gas and Solutions by a Catalyst Preplaced Sensor Based on a Pillar[5]arene Derivative. ACS Sustainable Chemistry & Engineering, 6(7), 8775-8781. doi:10.1021/acssuschemeng.8b01124Cox, E. D., & Cook, J. M. (1995). The Pictet-Spengler condensation: a new direction for an old reaction. Chemical Reviews, 95(6), 1797-1842. doi:10.1021/cr00038a004Jonsson, G., Launosalo, T., Salomaa, P., Walle, T., Sjöberg, B., Bunnenberg, E., … Records, R. (1966). Fluorescence Studies on Some 6,7-Substituted 3,4-Dihydroisoquinolines Formed from 3-Hydroxytyramine (Dopamine) and Formaldehyde. Acta Chemica Scandinavica, 20, 2755-2762. doi:10.3891/acta.chem.scand.20-2755BJÖRKLUND, A., EHINGER, B., & FALCK, B. (1968). A METHOD FOR DIFFERENTIATING DOPAMINE FROM NORADRENALINE IN TISSUE SECTIONS BY MICROSPECTROFLUOROMETRY. Journal of Histochemistry & Cytochemistry, 16(4), 263-270. doi:10.1177/16.4.263Stöckigt, J., Antonchick, A. P., Wu, F., & Waldmann, H. (2011). The Pictet-Spengler Reaction in Nature and in Organic Chemistry. Angewandte Chemie International Edition, 50(37), 8538-8564. doi:10.1002/anie.201008071Allou, L., El Maimouni, L., & Le Calvé, S. (2011). Henry’s law constant measurements for formaldehyde and benzaldehyde as a function of temperature and water composition. Atmospheric Environment, 45(17), 2991-2998. doi:10.1016/j.atmosenv.2010.05.04

Resorcinol Functionalized Gold Nanoparticles for Formaldehyde Colorimetric Detection

[EN] Gold nanoparticles functionalized with resorcinol moieties have been prepared and used for detecting formaldehyde both in solution and gas phases. The detection mechanism is based on the color change of the probe upon the aggregation of the nanoparticles induced by the polymerization of the resorcinol moieties in the presence of formaldehyde. A limit of detection of 0.5 ppm in solution has been determined. The probe can be deployed for the detection of formaldehyde emissions from composite wood boards.We thank the Spanish Government (projects MAT2015-64139-C4-4-R and AGL2015-70235-C2-2-R (MINECO/FEDER)) and the Generalitat Valenciana (project PROMETEOII/2014/047) for support.Martínez-Aquino, C.; Costero, AM.; Gil Grau, S.; Gaviña, P. (2019). Resorcinol Functionalized Gold Nanoparticles for Formaldehyde Colorimetric Detection. Nanomaterials. 9(2):1-9. https://doi.org/10.3390/nano9020302S1992Salthammer, T. (2013). Formaldehyde in the Ambient Atmosphere: From an Indoor Pollutant to an Outdoor Pollutant? Angewandte Chemie International Edition, 52(12), 3320-3327. doi:10.1002/anie.201205984Bruemmer, K. J., Brewer, T. F., & Chang, C. J. (2017). Fluorescent probes for imaging formaldehyde in biological systems. Current Opinion in Chemical Biology, 39, 17-23. doi:10.1016/j.cbpa.2017.04.010Lang, I., Bruckner, T., & Triebig, G. (2008). Formaldehyde and chemosensory irritation in humans: A controlled human exposure study. Regulatory Toxicology and Pharmacology, 50(1), 23-36. doi:10.1016/j.yrtph.2007.08.012IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol. 100F (2012). Chemical Agents and Related Occupations: Formaldehydehttps://monographs.iarc.fr/wp-content/uploads/2018/06/mono100F-29.pdfChung, P.-R., Tzeng, C.-T., Ke, M.-T., & Lee, C.-Y. (2013). Formaldehyde Gas Sensors: A Review. Sensors, 13(4), 4468-4484. doi:10.3390/s130404468Soman, A., Qiu, Y., & Chan Li, Q. (2008). HPLC-UV Method Development and Validation for the Determination of Low Level Formaldehyde in a Drug Substance. Journal of Chromatographic Science, 46(6), 461-465. doi:10.1093/chromsci/46.6.461Risholm-Sundman, M., Larsen, A., Vestin, E., & Weibull, A. (2007). Formaldehyde emission—Comparison of different standard methods. Atmospheric Environment, 41(15), 3193-3202. doi:10.1016/j.atmosenv.2006.10.079Kim, S., & Kim, H.-J. (2005). Comparison of standard methods and gas chromatography method in determination of formaldehyde emission from MDF bonded with formaldehyde-based resins. Bioresource Technology, 96(13), 1457-1464. doi:10.1016/j.biortech.2004.12.003Yeh, T.-S., Lin, T.-C., Chen, C.-C., & Wen, H.-M. (2013). Analysis of free and bound formaldehyde in squid and squid products by gas chromatography–mass spectrometry. Journal of Food and Drug Analysis, 21(2), 190-197. doi:10.1016/j.jfda.2013.05.010Toews, J., Rogalski, J. C., Clark, T. J., & Kast, J. (2008). Mass spectrometric identification of formaldehyde-induced peptide modifications under in vivo protein cross-linking conditions. Analytica Chimica Acta, 618(2), 168-183. doi:10.1016/j.aca.2008.04.049Zhou, X., Lee, S., Xu, Z., & Yoon, J. (2015). Recent Progress on the Development of Chemosensors for Gases. Chemical Reviews, 115(15), 7944-8000. doi:10.1021/cr500567rZhou, Y., Yan, J., Zhang, N., Li, D., Xiao, S., & Zheng, K. (2018). A ratiometric fluorescent probe for formaldehyde in aqueous solution, serum and air using aza-cope reaction. Sensors and Actuators B: Chemical, 258, 156-162. doi:10.1016/j.snb.2017.11.043Chaiendoo, K., Sooksin, S., Kulchat, S., Promarak, V., Tuntulani, T., & Ngeontae, W. (2018). A new formaldehyde sensor from silver nanoclusters modified Tollens’ reagent. Food Chemistry, 255, 41-48. doi:10.1016/j.foodchem.2018.02.030El Sayed, S., Pascual, L., Licchelli, M., Martínez-Máñez, R., Gil, S., Costero, A. M., & Sancenón, F. (2016). Chromogenic Detection of Aqueous Formaldehyde Using Functionalized Silica Nanoparticles. ACS Applied Materials & Interfaces, 8(23), 14318-14322. doi:10.1021/acsami.6b03224Martínez-Aquino, C., Costero, A., Gil, S., & Gaviña, P. (2018). A New Environmentally-Friendly Colorimetric Probe for Formaldehyde Gas Detection under Real Conditions. Molecules, 23(10), 2646. doi:10.3390/molecules23102646Guo, X.-L., Chen, Y., Jiang, H.-L., Qiu, X.-B., & Yu, D.-L. (2018). Smartphone-Based Microfluidic Colorimetric Sensor for Gaseous Formaldehyde Determination with High Sensitivity and Selectivity. Sensors, 18(9), 3141. doi:10.3390/s18093141Gangopadhyay, A., Maiti, K., Ali, S. S., Pramanik, A. K., Guria, U. N., Samanta, S. K., … Mahapatra, A. K. (2018). A PET based fluorescent chemosensor with real time application in monitoring formaldehyde emissions from plywood. Analytical Methods, 10(24), 2888-2894. doi:10.1039/c8ay00514aBi, A., Yang, S., Liu, M., Wang, X., Liao, W., & Zeng, W. (2017). Fluorescent probes and materials for detecting formaldehyde: from laboratory to indoor for environmental and health monitoring. RSC Advances, 7(58), 36421-36432. doi:10.1039/c7ra05651fSaha, K., Agasti, S. S., Kim, C., Li, X., & Rotello, V. M. (2012). Gold Nanoparticles in Chemical and Biological Sensing. Chemical Reviews, 112(5), 2739-2779. doi:10.1021/cr2001178Mayer, K. M., & Hafner, J. H. (2011). Localized Surface Plasmon Resonance Sensors. Chemical Reviews, 111(6), 3828-3857. doi:10.1021/cr100313vKong, B., Zhu, A., Luo, Y., Tian, Y., Yu, Y., & Shi, G. (2011). Sensitive and Selective Colorimetric Visualization of Cerebral Dopamine Based on Double Molecular Recognition. Angewandte Chemie International Edition, 50(8), 1837-1840. doi:10.1002/anie.201007071Ma, P., Liang, F., Wang, D., Yang, Q., Ding, Y., Yu, Y., … Wang, X. (2014). Ultrasensitive determination of formaldehyde in environmental waters and food samples after derivatization and using silver nanoparticle assisted SERS. Microchimica Acta, 182(3-4), 863-869. doi:10.1007/s00604-014-1400-9Wen, G., Liang, X., Liang, A., & Jiang, Z. (2015). Gold Nanorod Resonance Rayleigh Scattering-Energy Transfer Spectral Determination of Trace Formaldehyde with 4-Amino-3-Hydrazino-5-Mercap-1,2,4-Triazole. Plasmonics, 10(5), 1081-1088. doi:10.1007/s11468-015-9893-6Fauzia, V., Nurlely, Imawan, C., Narayani, N. M. M. S., & Putri, A. E. (2018). A localized surface plasmon resonance enhanced dye-based biosensor for formaldehyde detection. Sensors and Actuators B: Chemical, 257, 1128-1133. doi:10.1016/j.snb.2017.11.031Al-Muhtaseb, S. A., & Ritter, J. A. (2003). Preparation and Properties of Resorcinol-Formaldehyde Organic and Carbon Gels. Advanced Materials, 15(2), 101-114. doi:10.1002/adma.200390020Martí, A., Costero, A. M., Gaviña, P., & Parra, M. (2015). Selective colorimetric NO(g) detection based on the use of modified gold nanoparticles using click chemistry. Chemical Communications, 51(15), 3077-3079. doi:10.1039/c4cc10149aGodoy-Reyes, T. M., Llopis-Lorente, A., Costero, A. M., Sancenón, F., Gaviña, P., & Martínez-Máñez, R. (2018). Selective and sensitive colorimetric detection of the neurotransmitter serotonin based on the aggregation of bifunctionalised gold nanoparticles. Sensors and Actuators B: Chemical, 258, 829-835. doi:10.1016/j.snb.2017.11.181Lewicki, J. P., Fox, C. A., & Worsley, M. A. (2015). On the synthesis and structure of resorcinol-formaldehyde polymeric networks – Precursors to 3D-carbon macroassemblies. Polymer, 69, 45-51. doi:10.1016/j.polymer.2015.05.016Martí, A., Costero, A. M., Gaviña, P., Gil, S., Parra, M., Brotons-Gisbert, M., & Sánchez-Royo, J. F. (2013). Functionalized Gold Nanoparticles as an Approach to the Direct Colorimetric Detection of DCNP Nerve Agent Simulant. 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Identificación bioinformática y análisis funcional de factores de transcripción de Pseudomonas savastanoi potencialmente implicados en la infección de Mandevilla spp.

La bacteria fitopatógena Pseudomonas savastanoi, perteneciente al complejo Pseudomonas syringae, incluye 4 patovares aislados de diferentes plantas leñosas: pv. savastanoi (olivo), pv. nerii (adelfa), pv. fraxini (fresno) y pv. retacarpa (retama). Recientemente, se ha caracterizado en nuestro grupo un nuevo patovar causante de necrosis bacteriana en la planta ornamental dipladenia (Mandevilla spp.) (Caballo-Ponce, E, 2017, Tesis Doctoral). Estudios filogenéticos han demostrado la estrecha relación entre cepas del patovar nerii (Psn) y las aisladas de Mandevilla spp. (Psm), sin embargo, éstas difieren en el rango de huésped. En este trabajo hemos llevado a cabo un análisis bioinformático comparativo del repertorio de posibles factores de transcripción codificados en los genomas de la cepa Ph3 de Psm y de las cepas de Psn ICMP16943 (capaz de infectar dipladenia y adelfa) y ESC23 (infecta solamente adelfa). De la comparativa bioinformática de un total de 500 posibles factores de transcripción, se han seleccionado 9 de ellos: 3 factores exclusivos de Psm Ph3, 2 factores truncados en Psm Ph3 y 4 factores ausentes en las cepas capaces de infectar dipladenia (Psn ICMP16943 y Psm Ph3). La ausencia/presencia o el truncamiento de los genes codificadores de estos factores se ha comprobado en estas y otras cepas de P. savastanoi mediante técnicas de PCR y secuenciación. Actualmente estamos llevando a cabo la construcción de mutantes en los factores seleccionados para determinar su papel en la infección de dipladenia. Este trabajo pretende contribuir en el conocimiento de los determinantes genéticos implicados en la especificidad de huésped de los diversos patovares de la especie P. savastanoi.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Identificación bioinformática y análisis funcional de factores de transcripción de Pseudomonas savastanoi potencialmente implicados en la infección de Mandevilla spp.

La bacteria fitopatógena Pseudomonas savastanoi, perteneciente al complejo Pseudomonas syringae, incluye cuatro patovares aislados de diferentes plantas leñosas: pv. savastanoi (olivo), pv. nerii (adelfa), pv. fraxini (fresno) y pv. retacarpa (retama). Recientemente, se ha caracterizado en nuestro grupo un nuevo patovar (Psm) causante de necrosis bacteriana en la planta ornamental dipladenia (Mandevilla spp.) (Caballo-Ponce, E, 2017, Tesis Doctoral). Estudios filogenéticos han demostrado la estrecha relación existente entre cepas del patovar nerii (Psn) y las aisladas de Mandevilla spp., aun cuando éstas difieren en el rango de huésped. En este trabajo hemos llevado a cabo un análisis bioinformático comparativo del repertorio de posibles factores de transcripción (Fts) codificados en los genomas de la cepa Ph3 de Psm y de las cepas de Psn ICMP16943 y ESC23. La búsqueda se centró en aquellos Fts posiblemente implicados en la infección de dipladenia, seleccionando un total de nueve posibles Fts: tres factores exclusivos de Psm Ph3, dos factores truncados exclusivamente en Psm Ph3 y cuatro factores ausentes tanto en Psn ICMP16943 como Psm Ph3 (las dos cepas que infectan dipladenia). De entre los TFs identificados, hemos seleccionados tres que forman parte de un posible operón junto a otros genes implicados en quimiotaxis. Se han construido mutantes de este operón en cada uno de los tres genes codificadores de los Fts seleccionados y en dos genes codificadores de Methyl Chemotaxis proteins (MCP). Actualmente estamos analizando el papel de estos genes en la patogenicidad en plantas de dipladenia y su implicación en quimiotaxis. Este trabajo pretende contribuir en el conocimiento de los determinantes genéticos implicados en la especificidad de huésped de los diversos patovares de la especie P. savastanoi.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

DarkMix: Mixture Models for the Detection and Characterization of Dark Matter Halos

Dark matter simulations require statistical techniques to properly identify and classify their halos and structures. Nonparametric solutions provide catalogs of these structures but lack the additional learning of a model-based algorithm and might misclassify particles in merging situations. With mixture models, we can simultaneously fit multiple density profiles to the halos that are found in a dark matter simulation. In this work, we use the Einasto profile (Einasto 1965, 1968, 1969) to model the halos found in a sample of the Bolshoi simulation (Klypin et al. 2011), and we obtain their location, size, shape and mass. Our code is implemented in the R statistical software environment and can be accessed on https://github.com/LluisHGil/darkmix.Comment: 25 pages, 22 figures, 5 table

Reductive Elimination Reactions in Gold(III) Complexes Leading to C(sp3)–X (X = C, N, P, O, Halogen) Bond Formation: Inner-Sphere vs SN2 Pathways

© 2023. The authors. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the submitted version of a published work that appeared in final form in Inorganic Chemistry.The reactions leading to the formation of C–heteroatom bonds in the coordination sphere of Au(III) complexes are uncommon, and their mechanisms are not well known. This work reports on the synthesis and reductive elimination reactions of a series of Au(III) methyl complexes containing different Au–heteroatom bonds. Complexes [Au(CF3)(Me)(X)(PR3)] (R = Ph, X = OTf, OClO3, ONO2, OC(O)CF3, F, Cl, Br; R = Cy, X = Me, OTf, Br) were obtained by the reaction of trans-[Au(CF3)(Me)2(PR3)] (R = Ph, Cy) with HX. The cationic complex cis-[Au(CF3)(Me)(PPh3)2]OTf was obtained by the reaction of [Au(CF3)(Me)(OTf)(PPh3)] with PPh3. Heating these complexes led to the reductive elimination of MeX (X = Me, Ph3P+, OTf, OClO3, ONO2, OC(O)CF3, F, Cl, Br). Mechanistic studies indicate that these reductive elimination reactions occur either through (a) the formation of tricoordinate intermediates by phosphine dissociation, followed by reductive elimination of MeX, or (b) the attack of weakly coordinating anionic (TfO– or ClO4–) or neutral nucleophiles (PPh3 or NEt3) to the Au-bound methyl carbon. The obtained results show for the first time that the nucleophilic substitution should be considered as a likely reductive elimination pathway in Au(III) alkyl complexes

Ultratrace arsenic determination through hydride trapping on oxidized multiwall carbon nanotubes coupled to electrothermal atomic absorption spectrometry

Arsenic determination in natural waters is an issue of current research. This article reports a novel hydride generation (HG) approach developed for As determination with electrothermal atomic absorption spectrometry (ETAAS) detection. The HG process was interfaced with ETAAS through hydride trapping onto a carbon nanotubes microcolumn. To this end a homemade gas-liquid separator was used, allowing arsine formation and its flow throughout the CNT microcolumn. The retention process involved thus a solid phase extraction from the gas phase to the solid support. Once arsine generation was completed, the elution was carried out with nitric acid directly onto the dosing hole of the graphite furnace. Outstanding sensitivity with detection limit of 1 ng L-1, quantification limit of 5 ng L-1 and the characteristic mass, 5.8 ± 0.4 pg could be achieved. A satisfactory correlation between concentration of As and absorbance (R = 0.9993) from the limit of quantification up to 500 ng L-1, with a relative standard deviation of 6.3% were obtained. A sensitive enhancement factor of 38 was reached when 2 mL of sample were processed and 50 μL of HNO3 were used as eluent. The system was successfully applied to the analysis of a standard reference material, QC LL2 metals in natural waters. In addition tap water analysis provided an As concentration of 0.29±0.03 μg L-1.Fil: Maratta Martínez, Sergio Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Acosta, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Martinez, Luis Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Pacheco, Pablo Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; ArgentinaFil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Química de San Luis; Argentin

Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers

The authors would gratefully like to acknowledge the financial support given by Fondo de Investigaciones Sanitarias (reference PI10/00527). They are also grateful to the Spanish Ministry of Education, Culture and Sport for awarding Pablo Olmedo a FPU predoctoral fellowship (reference AP2009-0534) to achieve his PhD degree in the context of this research project.Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).Instituto de Salud Carlos III PI10/00527Spanish Ministry of Education, Culture and Sport AP2009-053

Use of 2-D Dige and preparative denaturing IEF to enhance sensitivity in the differential protein expression analysis of Candida Albicans yeast-to-Hypha transition

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