Effect of pectinolytic microbial enzymes and bacteria application on germination response of yellow passion fruit (Passiflora edulis var. flavicarpa) seeds

El maracuyá (Passiflora edulis var. flavicarpa) es un fruto apetecido por su sabor y valor nutricional, por lo que es cultivado en muchos países, como Colombia. La producción del fruto se realiza generalmente a partir de semillas, las cuales tienen dormancia mecánica por la cubierta seminal, lo que dificulta su germinación y desarrollo, afectando el rendimiento en los cultivos. Este trabajo evaluó la capacidad de microorganismos pectinolíticos procedentes de la Colección de la Pontificia Universidad Javeriana para degradar la cubierta seminal y facilitar la germinación de semillas de maracuyá. A partir de frutos de maracuyá del Huila, se extrajeron sus semillas y, por grupos, se lavaron con agua y Pectinex USPL. Posteriormente, las semillas lavadas se expusieron a inóculos y pectinasas de B. cereus y B. subtilis por 48 horas, y se evaluó por 45 días el número de semillas germinadas. Las semillas lavadas con Pectinex y expuestas a pectinasas de B. subtilis tuvieron mayor porcentaje (11%) y velocidad de germinación (1.91 semillas/día) con significancia estadística. El uso de pectinasas de B. subtilis¸ por lo tanto, podría ser considerado en protocolos de acondicionamiento de semillas de maracuyá en Colombia.Yellow passion fruit (Passion edulis var. flavicarpa) is a desired fruit for its taste and nutritional value, therefore is cultivated in many countries, as Colombia. The fruit production is usually made by seeds, which have mechanic dormancy due to their hard coat, which complicates their germination and development affecting the harvest yield. This study evaluated the ability of pectinolytic microorganisms from Pontificia Universidad Javeriana Collection to degrade the seed hard core and to contribute to yellow passion fruit seeds germination. From yellow passion fruit from Huila, it was extracted their seeds and by groups they were washed with water and Pectinex USPL. Later, the seeds washed were exposed to inoculum and pectinases from B. creus and B. subtilis for 48 hours, and it was evaluated for 45 days the number of sprouted seeds. The seeds washed with Pectinex and exposed to B. subtilis pectinases showed highest germination percentage (11%) and rate (191 seed/day) with statistical significance. The use of B. subtilis pectinases, therefore, could be considered in conditioning protocols for yellow passion fruit seeds in ColombiaBiólogo (a)Pregrad

Plan de mejoramiento de calidad en equipos biomédicos de uci's y cuidados intermedios de la clínica universitaria Rafael Uribe Uribe

En el siguiente documento se presenta la propuesta de un plan de mejoramiento de calidad en equipos biomédicos de las áreas de cuidados intensivos y cuidados intermedios para la Clínica Rafael Uribe Uribe de la ciudad Santiago de Cali. Para el desarrollo de este plan de mejoramiento se aplicaron los conocimientos adquiridos en el enfoque de ingeniería clínica a lo largo de la carrera de ingeniería biomédica. Teniendo en cuenta la normativa vigente para la habilitación de servicios para prestadores de salud (resolución 2003 de 2014), se aplicó el estándar de habilitación: dotación, en los servicios de cuidados intensivos neonatal, cuidados intensivos pediátricos, cuidados intensivos adultos, cuidados intermedios neonatal y cuidados intermedios adultos, para determinar la línea base en la que se encuentra la clínica respecto a esta normativa y así incluir en el plan de mejoramiento las deficiencias obtenidas. Para el inicio del proyecto se realizó el reconocimiento de las áreas a trabajar, inventario de equipos existentes en cada área, verificación de hojas de vidas de los equipos, verificación de planes de mantenimiento y control metrológico de los equipos biomédicos. Teniendo en cuenta la información especificada anteriormente, se actualizaron hojas de vida de los equipos, se diseñaron protocolos de: seguridad eléctrica entorno paciente, inspección y mantenimiento preventivo, control metrológico, baja de equipos y manejo seguro para equipos biomédicos. Como resultado se obtuvo un manual de calidad donde se consignaron todos los protocolos diseñados y un plan de mejoramiento de calidad, documento operativo, que identificó no conformidades, determinó la acción a emprender para resolver la no conformidad, asignó participantes y responsables en su solución y estableció tiempo de cumplimientoPregradoIngeniero(a) Biomédico(a

New insights into cancer: MDM2 binds to the citrullinating enzyme PADI4

PADI4 is one of the human isoforms of a family of enzymes implicated in the conversion of arginine to citrulline. MDM2 is an E3 ubiquitin ligase which is crucial for down-regulation of degradation of the tumor suppressor gene p53. Given the relationship between both PADI4 and MDM2 with p53-signaling pathways, we hypothesized they may interact directly, and this interaction could be relevant in the context of cancer. Here, we showed their association in the nucleus and cytosol in several cancer cell lines. Furthermore, binding was hampered in the presence of GSK484, an enzymatic PADI4 inhibitor, suggesting that MDM2 could bind to the active site of PADI4, as confirmed by in silico experiments. In vitro and in silico studies showed that the isolated N-terminal region of MDM2, N-MDM2, interacted with PADI4, and residues Thr26, Val28, Phe91 and Lys98 were more affected by the presence of the enzyme. Moreover, the dissociation constant between N-MDM2 and PADI4 was comparable to the IC50 of GSK484 from in cellulo experiments. The interaction between MDM2 and PADI4 might imply MDM2 citrullination, with potential therapeutic relevance for improving cancer treatment, due to the generation of new antigens

Measurement of the (90,91,92,93,94,96)Zr(n,gamma) and (139)La(n,gamma) cross sections at n_TOF

Open AccessNeutron capture cross sections of Zr and La isotopes have important implications in the field of nuclear astrophysics as well as in the nuclear technology. In particular the Zr isotopes play a key role for the determination of the neutron density in the He burning zone of the Red Giant star, while the (139)La is important to monitor the s-process abundances from Ba up to Ph. Zr is also largely used as structural materials of traditional and advanced nuclear reactors. The nuclear resonance parameters and the cross section of (90,91,92,93,94,96)Zr and (139)La have been measured at the n_TOF facility at CERN. Based on these data the capture resonance strength and the Maxwellian-averaged cross section were calculated

Measurements of high-energy neutron-induced fission of (nat)Pb and (209)Bi

This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License 3.0, which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly citedThe CERN Neutron Time-Of-Flight (n_TOF) facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV

Measurement of the neutron capture cross section of the s-only isotope 204Pb from 1 eV to 440 keV

The neutron capture cross section of 204Pb has been measured at the CERN n_TOF installation with high resolution in the energy range from 1 eV to 440 keV. An R-matrix analysis of the resolved resonance region, between 1 eV and 100 keV, was carried out using the SAMMY code. In the interval between 100 keV and 440 keV we report the average capture cross section. The background in the entire neutron energy range could be reliably determined from the measurement of a 208Pb sample. Other systematic effects in this measurement could be investigated and precisely corrected by means of detailed Monte Carlo simulations. We obtain a Maxwellian average capture cross section for 204Pb at kT=30 keV of 79(3) mb, in agreement with previous experiments. However our cross section at kT=5 keV is about 35% larger than the values reported so far. The implications of the new cross section for the s-process abundance contributions in the Pb/Bi region are discussed.Comment: 8 pages, 3 figures, article submitted to Phys. Rev.

New measurement of neutron capture resonances of 209Bi

The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19(3)% of the solar bismuth abundance, resulting in an r-process residual of 81(3)%. The present (n,gamma) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target.Comment: 10 pages, 5figures, recently published in Phys. Rev.

Resonance capture cross section of 207Pb

The radiative neutron capture cross section of 207Pb has been measured at the CERN neutron time of flight installation n_TOF using the pulse height weighting technique in the resolved energy region. The measurement has been performed with an optimized setup of two C6D6 scintillation detectors, which allowed us to reduce scattered neutron backgrounds down to a negligible level. Resonance parameters and radiative kernels have been determined for 16 resonances by means of an R-matrix analysis in the neutron energy range from 3 keV to 320 keV. Good agreement with previous measurements was found at low neutron energies, whereas substantial discrepancies appear beyond 45 keV. With the present results, we obtain an s-process contribution of 77(8)% to the solar abundance of 207Pb. This corresponds to an r-process component of 23(8)%, which is important for deriving the U/Th ages of metal poor halo stars.Comment: 7 pages, 3 figures, to be published in Phys. Rev.

Measurement of the radiative neutron capture cross section of 206Pb and its astrophysical implications

The (n, gamma) cross section of 206Pb has been measured at the CERN n_TOF facility with high resolution in the energy range from 1 eV to 600 keV by using two optimized C6D6 detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture gamma-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched 208Pb sample. The effect of the lower energy cutoff in the pulse height spectra of the C6D6 detectors was carefully corrected via Monte Carlo simulations. Compared to previous 206Pb values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results have a direct impact on the s-process abundance of 206Pb, which represents an important test for the interpretation of the cosmic clock based on the decay of 238U.Comment: 11 pages, 8 figures, paper to be submitted to Phys. Rev.

High-accuracy determination of the U 238 / U 235 fission cross section ratio up to ≈1 GeV at n-TOF at CERN

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOIThe U238 to U235 fission cross section ratio has been determined at n-TOF up to ≈1 GeV, with two different detection systems, in different geometrical configurations. A total of four datasets has been collected and compared. They are all consistent to each other within the relative systematic uncertainty of 3-4%. The data collected at n-TOF have been suitably combined to yield a unique fission cross section ratio as a function of neutron energy. The result confirms current evaluations up to 200 MeV. Good agreement is also observed with theoretical calculations based on the INCL++/Gemini++ combination up to the highest measured energy. The n-TOF results may help solve a long-standing discrepancy between the two most important experimental datasets available so far above 20 MeV, while extending the neutron energy range for the first time up to ≈1 GeV.Peer reviewedFinal Published versio