Desarrollo y aplicación de un polímero de impronta molecular para la extracción del plaguicida MCPA en muestras de agua

[ES] En el análisis de muestras medioambientales, el estudio de los procesos de tratamiento previo de la muestra para la extracción del compuesto de interés, así como su preconcentración y limpieza, están en pleno desarrollo. Los polímeros de impronta molecular (MIP) son polímeros estables, sintetizados en el laboratorio en presencia del compuesto a determinar, que presentan características de reconocimiento molecular aumentando la selectividad en los procesos de extracción. En el proyecto se va a desarrollar un MIP que permita la extracción selectiva del herbicida ácido 2-metil-4-clorofenoxiacético (MCPA). El polímero se obtendrá térmicamente a partir de una mezcla que contiene un monómero, un entrecruzante, un disolvente porogénico y un iniciador radicalario. La mezcla de polimerización contendrá además una determinada cantidad del MCPA, que se eliminará tras la polimerización dejando su huella en la estructura. El mismo polímero sintetizado en ausencia del plaguicida (polímero sin impronta, NIP) se utilizará como referencia. El polímero, se empaquetará en cartuchos, que servirán de soporte para realizar la extracción en fase sólida del plaguicida, permitiendo la preconcentración del mismo y la limpieza de las muestras. Esta etapa de extracción resultará esencial en el análisis de muestras de agua reales, dadas las bajas concentraciones de plaguicidas permitidas (nivel máximo permitido para plaguicidas individuales 0.1 µg/L). Tras la etapa de extracción, el plaguicida se analizará mediante cromatografía líquida de alta resolución. Las condiciones de la polimerización (composición, lavado, tiempo de contacto, etc.) se optimizarán con el objetivo de conseguir una extracción selectiva del plaguicida. Se establecerán las características óptimas de las etapas de extracción en fase sólida (lavado, tipo y volumen de eluyente, capacidad de preconcentración, reusabilidad, etc) para el plaguicida MCPA. La especificidad del polímero se estudiará mediante la extracción de otros plaguicidas fenoxiácidos con estructuras similares. Finalmente, se aplicará el polímero MIP para la extracción en fase sólida del MCPA en muestras de agua de diferente procedencia.[EN] In the analysis of enviromental samples, the improvement of sample treatment processes for the extraction of target compounds, as well as its pre-concentration and cleaning, are in full development. This extraction step is essential in the analysis of pesticides in real water samples, due to their low concentrations allowed (maximum residue limit for individual pesticides is 0.1 µg/L). Molecularly imprinted polymers (MIPs) are stable polymers, synthesized in the laboratory in presence of the selected analyte (template), which have moleculary recognition characteristics that increase the selectivity in the extraction process. In this work, a MIP that permits the selective extraction of the 2-methyl-4-chlorophenoxyacetic (MCPA) herbicide has been developed. The polymer has been thermally obtained from a mixture containing a monomer, a crosslinker, a porogen and a radical initiator. The polymerization mixture also contained an amount of MCPA, which was eliminated after polymerization leaving a mark on the structure. Also a polymer in the absence of plaguicide was synthetised (non imprinted polymer). The powder of the synthesized polymer has been packed into cartridges to perform the solid phase extraction of MCPA. After that, the analysis of the pesticide has been carried out by high performance liquid chromatography. The polymerization conditions (monomer, porogen and monomer-template contact time) have been optimized with the aim of achieving a selective extraction of the plaguicide. In addition, optimal conditions for the solid phase extraction of the MCPA (washing solvent, type and volume of eluent, preconcentration capacity, etc.) have been established, and the extraction capacity of the sorbent for other phenoxyacid plaguicides with similar structures has been proven. Finally, the MIP polymer has been applied to the solid phase extraction of MCPA and other 5 phenoxyacid plaguicides in real water samples from different sources.Beltrán Martí, R. (2019). Desarrollo y aplicación de un polímero de impronta molecular para la extracción del plaguicida MCPA en muestras de agua. Universitat Politècnica de València. http://hdl.handle.net/10251/126134TFG

Spectral self-imaging effect by time-domain multilevel phase modulation of a periodic pulse train

[EN] We propose and analyze a novel (to our knowledge) approach to implement the spectral self-imaging effect of optical frequency combs. The technique is based on time-domain multilevel phase-only modulation of a periodic optical pulse train. The method admits both infinite- and finite-duration periodic pulse sequences. We show that the fractional spectral self-imaging effect allows one to reduce by an integer factor the comb frequency spacing. Numerical simulation results support our theoretical analysis. © 2011 Optical Society of America.This work has been supported by the Generalitat Valenciana (Grant GV/2009/044), by the Vicerrectorado de Investigacion, Universidad Politecnica de Valencia (Grant PAID-06-08/3276) and by the Ministerio de Ciencia e Innovacion of Spain under Project "Plan Nacional de I+D+I TEC2007-68065-C03-02". J. Caraquitena and M. Beltran also acknowledge financial support from the Ministerio de Ciencia e Innovacion through the "Juan de la Cierva" research program and FPI Grant BES-2006-12066, respectively.Caraquitena Sales, J.; Beltrán, M.; Llorente, R.; Martí Sendra, J.; Muriel, MA. (2011). Spectral self-imaging effect by time-domain multilevel phase modulation of a periodic pulse train. Optics Letters. 36(6):858-860. https://doi.org/10.1364/OL.36.000858S858860366Jannson, T., & Jannson, J. (1981). Temporal self-imaging effect in single-mode fibers. Journal of the Optical Society of America, 71(11), 1373. doi:10.1364/josa.71.001373Azaña, J., & Muriel, M. A. (1999). Technique for multiplying the repetition rates of periodic trains of pulses by means of a temporal self-imaging effect in chirped fiber gratings. Optics Letters, 24(23), 1672. doi:10.1364/ol.24.001672Arahira, S., Kutsuzawa, S., Matsui, Y., Kunimatsu, D., & Ogawa, Y. (1998). Repetition-frequency multiplication of mode-locked pulses using fiber dispersion. Journal of Lightwave Technology, 16(3), 405-410. doi:10.1109/50.661368Longhi, S., Marano, M., Laporta, P., Svelto, O., Belmonte, M., Agogliati, B., … Ibsen, M. (2000). 40-GHz pulse-train generation at 15 µm with a chirped fiber grating as a frequency multiplier. Optics Letters, 25(19), 1481. doi:10.1364/ol.25.001481Azaña, J. (2005). Spectral Talbot phenomena of frequency combs induced by cross-phase modulation in optical fibers. Optics Letters, 30(3), 227. doi:10.1364/ol.30.000227Bellemare, A., Karasek, M., Rochette, M., LRochelle, S., & Tetu, M. (2000). Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid. Journal of Lightwave Technology, 18(6), 825-831. doi:10.1109/50.848393Caraquitena, J., & Martí, J. (2009). Dynamic spectral line-by-line pulse shaping by frequency comb shifting. Optics Letters, 34(13), 2084. doi:10.1364/ol.34.002084Azaña, J., & Gupta, S. (2006). Complete family of periodic Talbot filters for pulse repetition rate multiplication. Optics Express, 14(10), 4270. doi:10.1364/oe.14.004270Caraquitena, J., Jiang, Z., Leaird, D. E., & Weiner, A. M. (2007). Tunable pulse repetition-rate multiplication using phase-only line-by-line pulse shaping. Optics Letters, 32(6), 716. doi:10.1364/ol.32.000716Jiang, Z., Huang, C.-B., Leaird, D. E., & Weiner, A. M. (2007). Optical arbitrary waveform processing of more than 100 spectral comb lines. Nature Photonics, 1(8), 463-467. doi:10.1038/nphoton.2007.139Weiner, A. M. (2000). Femtosecond pulse shaping using spatial light modulators. Review of Scientific Instruments, 71(5), 1929-1960. doi:10.1063/1.1150614Kolner, B. H. (1994). Space-time duality and the theory of temporal imaging. IEEE Journal of Quantum Electronics, 30(8), 1951-1963. doi:10.1109/3.301659Godil, A. A., Auld, B. A., & Bloom, D. M. (1994). Picosecond time-lenses. IEEE Journal of Quantum Electronics, 30(3), 827-837. doi:10.1109/3.286176Salem, R., Foster, M. A., Turner, A. C., Geraghty, D. F., Lipson, M., & Gaeta, A. L. (2008). Optical time lens based on four-wave mixing on a silicon chip. Optics Letters, 33(10), 1047. doi:10.1364/ol.33.001047Winzer, P. J., & Essiambre, R.-J. (2006). Advanced Modulation Formats for High-Capacity Optical Transport Networks. Journal of Lightwave Technology, 24(12), 4711-4728. doi:10.1109/jlt.2006.88526

Efecto de la bomba de pistones de los pulverizadores hidraúlicos sobre la viabilidad de los conidios de Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) y su infectividad sobre Ceratitis capitata Wiedemann (Diptera: Tephritidae)

Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) es una especie de hongo entomopatógeno ampliamente utilizada para el control de diferentes plagas. Actualmente, existen diferentes formulados comerciales. Su aplicación se realiza utilizando los mismos pulverizadores que para los plaguicidas químicos. Las diferentes partes de estos equipos (bombas, filtros, boquillas, etc.) pueden producir daños a los conidios presentes en la mezcla, disminuyendo su eficacia en el control de plagas. Una de las bombas más utilizadas en los pulverizadores es la bomba de pistones. El objetivo de este trabajo fue estudiar el efecto de estas bombas sobre la viabilidad de los conidios de B. bassiana y su infectividad sobre Ceratitis capitata Wiedemann (Diptera: Tephritidae)

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Optimización de la aplicación de fitosanitarios en cítricos (I)

En este artículo se repasan algunas de las contribuciones queel Centro de Agroingeniería del Instituto Valenciano de Investigaciones Agrarias ha realizado para la optimización de la aplicación de fitosanitarios en tratamientos mecanizados con el objetivo de alcanzar un control de plagas y enfermedades en cltricos sostenible económica y medioambientalmente. Se describen las aplicaciones y herramientas relacionadas con la optimización de la dosis de aplicación, dejando para una segunda parte, que se publicará en próximos números,el correcto funcionamiento y ajuste de las máquinas tradicionales y la utilización de nuevas tecnologías de aplicación precisa

Reconfigurable multiwavelength source based on electrooptic phase modulation of a pulsed laser

[EN] A reconfigurable multiwavelength source based on time-domain electrooptic phase modulation of a pulsed laser is proposed and experimentally demonstrated. The technique permits great reconfiguration in the spectrum allocation and wavelength separation. A tunable 5-GHz and 2.5-GHz frequency spacing from a 10-GHz mode-locked laser is experimentally demonstrated. A 5-GHz frequency shift is also demonstrated.Manuscript received March 02, 2011; revised April 21, 2011; accepted May 21, 2011. Date of publication May 27, 2011; date of current version July 27, 2011. This work was supported in part by the European Commission under the FP7-ICT-249142 FIVER and FP7-ICT-216863 BONE Projects. The work of M. Beltran was supported by the Ministerio de Ciencia e Innovacion, Spain, under FPI Grant BES-2006-12066.Beltrán Ramírez, M.; Caraquitena Sales, J.; Llorente Sáez, R.; Martí Sendra, J. (2011). Reconfigurable multiwavelength source based on electrooptic phase modulation of a pulsed laser. IEEE Photonics Technology Letters. 23(16):1175-1177. https://doi.org/10.1109/LPT.2011.2157967S11751177231

Anuario del Centro de Estudios Martianos (Vol. 26 2003)

El Anuario del Centro de Estudios Martianos es la publicación insignia de esta institución y heredera directa del Anuario Martiano de la Biblioteca Nacional José Martí, que se publicó entre 1969 y 1977, bajo la dirección del poeta y ensayista Cintio Vitier. Desde que salió a la luz su primera entrega, en 1978, se han publicado treinta y cinco números, en los que aparecen artículos y ensayos de importantes estudiosos de la vida y obra del Apóstol, en Cuba y el resto del mundo. En sus secciones fijas (Otros textos de José Martí, Documentos, Estudios y aproximaciones, Vigencias, Publicaciones, Bibliografía, Constante) y los apartados especiales, los lectores pueden conocer disímiles temas del quehacer martiano internacional, en el año que termina además de mantenerse al tanto de las últimas contribuciones de los promotores e investigadores de la obra martiana en el orbe