Numerical modelling o bed sediment particle tracking in open channel with skewed box-culvert

A particle tracking model was applied to estimate the bed sediment transport in open channel with skewed box-culvert in rivers in Mexico, for which purpose the calculation of the hydrodynamics of the study channel was determined the three-dimensional velocity field [1], later, the calculation of particle transport was obtained, which was determined in any direction of the space caused by the velocity field and the turbulent dispersion (random movement of the Brownian type). The dispersion and re-suspension mechanisms of the particles used were represented by stochastic models, which describe the movement by means of a probability function [2]. The validation of the model was previously carried out by [3], obtaining average relative errors of less than 4.8%. Three numerical scenarios were calculated including different alternatives and its behaviour at the entrance, interior and exit of the water flow in the construction to determine which is the best option to be used on the skewed multi barrel crossings. In order to accomplish this, a variable slope channel and 1: 60 scale models of box culverts with 10, 22 and 45 degrees of skewedness were used. The results observed in the multi-eyed box culverts were favourable, due to the fact that the speed utside of them, which favours the hydrodynamic behaviour and minimize the accumulation of sediment into structure in the river

Evaluation of factors leading to poor outcomes for pediatric acute lymphoblastic leukemia in Mexico: a multi-institutional report of 2,116 patients

Background and aimsPediatric acute lymphoblastic leukemia (ALL) survival rates in low- and middle-income countries are lower due to deficiencies in multilevel factors, including access to timely diagnosis, risk-stratified therapy, and comprehensive supportive care. This retrospective study aimed to analyze outcomes for pediatric ALL at 16 centers in Mexico.MethodsPatients <18 years of age with newly diagnosed B- and T-cell ALL treated between January 2011 and December 2019 were included. Clinical and biological characteristics and their association with outcomes were examined.ResultsOverall, 2,116 patients with a median age of 6.3 years were included. B-cell immunophenotype was identified in 1,889 (89.3%) patients. The median white blood cells at diagnosis were 11.2.5 × 103/mm3. CNS-1 status was reported in 1,810 (85.5%), CNS-2 in 67 (3.2%), and CNS-3 in 61 (2.9%). A total of 1,488 patients (70.4%) were classified as high-risk at diagnosis. However, in 52.5% (991/1,889) of patients with B-cell ALL, the reported risk group did not match the calculated risk group allocation based on National Cancer Institute (NCI) criteria. Fluorescence in situ hybridization (FISH) and PCR tests were performed for 407 (19.2%) and 736 (34.8%) patients, respectively. Minimal residual disease (MRD) during induction was performed in 1,158 patients (54.7%). The median follow-up was 3.7 years. During induction, 191 patients died (9.1%), and 45 patients (2.1%) experienced induction failure. A total of 365 deaths (17.3%) occurred, including 174 deaths after remission. Six percent (176) of patients abandoned treatment. The 5-year event-free survival (EFS) was 58.9% ± 1.7% for B-cell ALL and 47.4% ± 5.9% for T-cell ALL, while the 5-year overall survival (OS) was 67.5% ± 1.6% for B-cell ALL and 54.3% ± 0.6% for T-cell ALL. The 5-year cumulative incidence of central nervous system (CNS) relapse was 5.5% ± 0.6%. For the whole cohort, significantly higher outcomes were seen for patients aged 1–10 years, with DNA index >0.9, with hyperdiploid ALL, and without substantial treatment modifications. In multivariable analyses, age and Day 15 MRD continued to have a significant effect on EFS.ConclusionOutcomes in this multi-institutional cohort describe poor outcomes, influenced by incomplete and inconsistent risk stratification, early toxic death, high on-treatment mortality, and high CNS relapse rate. Adopting comprehensive risk-stratification strategies, evidence-informed de-intensification for favorable-risk patients and optimized supportive care could improve outcomes

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

Experimental Analysis of Tunable Optical Spectral Imaging System Using a Grating in the Pupil Function

Hyperspectral imaging (HSI) systems have been demonstrated as a powerful imaging technique due to their high spectral resolution. HSI can obtain the spectrum for each pixel in the image of a scene, a feature that can be exploited to design optical systems with the purpose of analyzing and characterizing objects and identifying processes within the visible electromagnetic spectrum (bandwidth). In this paper, we present an HSI system comprising a diffraction grating placed in the exit pupil of our optical configuration. The spectrum for each pixel associated with the object appears in the first order of diffraction. We used this system to characterize and tune the required spectral band of the image of the captured object obtaining more information than with an optical imaging system. Accordingly, the proposed optical system is suitable to obtain spectral and hyperspectral imaging at low cost compared to an acousto-optic system or other HSI. The scanning system captures hundreds of spectral images associated with the object, obtaining a maximum spectral resolution of 0.26nm or 260 pm for one of our configurations

Malfunctioning of the iron-sulfur cluster assembly machinery in Saccharomyces cerevisiae produces oxidative stress via an iron-dependent mechanism, causing dysfunction in respiratory complexes.

Biogenesis and recycling of iron-sulfur (Fe-S) clusters play important roles in the iron homeostasis mechanisms involved in mitochondrial function. In Saccharomyces cerevisiae, the Fe-S clusters are assembled into apoproteins by the iron-sulfur cluster machinery (ISC). The aim of the present study was to determine the effects of ISC gene deletion and consequent iron release under oxidative stress conditions on mitochondrial functionality in S. cerevisiae. Reactive oxygen species (ROS) generation, caused by H2O2, menadione, or ethanol, was associated with a loss of iron homeostasis and exacerbated by ISC system dysfunction. ISC mutants showed increased free Fe2+ content, exacerbated by ROS-inducers, causing an increase in ROS, which was decreased by the addition of an iron chelator. Our study suggests that the increment in free Fe2+ associated with ROS generation may have originated from mitochondria, probably Fe-S cluster proteins, under both normal and oxidative stress conditions, suggesting that Fe-S cluster anabolism is affected. Raman spectroscopy analysis and immunoblotting indicated that in mitochondria from SSQ1 and ISA1 mutants, the content of [Fe-S] centers was decreased, as was formation of Rieske protein-dependent supercomplex III2IV2, but this was not observed in the iron-deficient ATX1 and MRS4 mutants. In addition, the activity of complexes II and IV from the electron transport chain (ETC) was impaired or totally abolished in SSQ1 and ISA1 mutants. These results confirm that the ISC system plays important roles in iron homeostasis, ROS stress, and in assembly of supercomplexes III2IV2 and III2IV1, thus affecting the functionality of the respiratory chain

Model proposed for the mechanism of mitochondrial generation of ROS dependent on free Fe²⁺ release from Fe–S-containing proteins in <i>S. cerevisiae</i>.

<p>The [2Fe–2S] commonly carried by the multi-protein complex (Ssq1-Jac1-Mge1-Grx5) can also be assembled into recipient apoproteins, such as the Rieske protein of cytochrome <i>bc1</i> from respiratory complex III. The Isa1 and Iba57 proteins may function as iron reservoirs, from which the metal can subsequently be transferred to [Fe–S] centers or heme prosthetic groups from cytochrome <i>bc₁</i>. When superoxide (O₂^•−) is generated by electron leaking in the ETC, and other ROS are produced by oxidative metabolism or by oxidant agents, the [4Fe–4S], [3Fe–4S], or [2Fe–2S] clusters contained in the ETC complexes are disrupted. This event provokes a generalized uncoupling/denaturation of Fe–S proteins, causing a release and thus an increment in the iron labile pool (Fe²⁺), which increases mitochondrial ROS levels via the Fenton and Haber–Weiss reactions. If the ISC assembly system is dysfunctional, supercomplex (III₂IV₂) formation is affected, as is [Fe–S] recycling, provoking ETC dysfunction. Hence, the levels of ROS generation increase in an additive manner by a vicious circle of disruption of iron-containing or iron storage proteins, causing an imbalanced ROS content (increment of species such as H₂O₂ and superoxide species), that provokes mitochondrial dysfunction and may ultimately lead to apoptotic events.</p

Kinetics of ROS generation in suspensions of <i>S. cerevisiae ISC</i> mutants treated with stressors.

<p>Yeast cultures were grown in liquid YPD medium without stressors and harvested in late exponential growth phase. Yeast YPD-grown cultures were incubated for 2 h with the respective ROS probe; then, the suspensions were treated with and without stressor (H₂O₂ 12 mM, menadione 80 µM, and ethanol 10%), incubated at 30°C with light shaking. Samples (100 µL) were taken and suspended in PBS buffer for determination of intracellular ROS levels by real-time analysis in a flow cytometer. A–F) Results represent the percentage of cells that showed positive fluorescence. Yeast suspensions without a stressor (dashed lines) and with a stressor treatment (continuous lines). The ROS fluorescent probes DHE (O₂^•− indicators) and DHR123 (mitochondrial ROS in general, mainly a H₂O₂ indicator) were used. A–C) Fluorescence determination using DHE probe, D–F) fluorescence determination using DHR123 probe. Values are the mean of three independent experiments with 20,000 cells counted by flow cytometry per each point. SEM values are indicated as bars (n = 3), one-way ANOVA was used to compare mutants versus to WT. Significant differences (<i>p</i><0.05) are indicated with (*).</p

Analyses of the functionality of mitochondrial respiratory chain complexes in <i>S. cerevisiae ISC</i> mutants.

<p>Mitochondrial functionality was evaluated in mitochondrial suspensions obtained from cultures grown in liquid YPD medium, cells were harvested in the late exponential growth phase, mitochondria were isolated and re-suspended in the appropriate buffer, and mitochondrial activities were measured as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111585#s2" target="_blank">Materials and Methods</a>. A) membrane potential, B) activity of succinate-DCIP oxidoreductase, C) activity of succinate-cytochrome <i>c</i> oxidoreductase, D) activity of glycerol-cytochrome <i>c</i> oxidoreductase, E) activity of L-lactate-cytochrome <i>c</i> oxidoreductase, and F) activity of cytochrome <i>c</i> oxidase. Values are the mean of three independent experiments. SE values are indicated as bars (n = 3), one-way ANOVA with Tukey's post-hoc test was used to compare yeast strains, and significant differences (<i>p</i><0.05) are indicated with different lowercase letters.</p

Respiration test of cell suspensions from <i>S. cerevisiae ISC</i> mutants.

<p>Mitochondrial functionality was evaluated in yeast suspensions obtained from cultures grown in liquid YPD medium, cells were harvested in the late exponential growth phase and re-suspended in MES-TEA buffer with glucose or with ethanol and incubated at 30°C with light shaking. Cells were used for oxygen consumption rate (OCR) measurements with a Clark-type oxygen electrode coupled to a biological oxygen monitor as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111585#s2" target="_blank">Materials and Methods</a>. A–C) Basal OCR with glucose as substrate, D–F) with ethanol treatment. A and D) OCR under coupled state conditions, B and E) OCR under uncoupled state conditions using CCCP for uncoupling, C and F) OCR under complex III blocking conditions using antimycin A as an inhibitor. Values are the mean of three independent experiments. SE values are indicated as bars (n = 3), one-way ANOVA with Tukey's post-hoc test was used to compare yeast strains, significant differences (<i>p</i><0.05) are indicated with different lowercase letters.</p