91 research outputs found
Coherent structures and bubble-particle velocity in 2-D fluidized beds
This work presents an experimental study to characterize ascending bubbles and granular velocity in the dense phase of a 2-D fluidized bed. Three different non-intrusive techniques based on images obtained with a high speed camera are developed, and applied to the images. First the bubble paths are characterized with time-average concentration maps and the bubble velocities are obtained, using a tracking algorithm over the mass centers of the bubbles. Finally, a PIV (particle image velocimetry) method is used to characterize the particle velocity vectors. This procedure is repeated for different bed aspect ratios, and different superficial gas velocities. This study analyzes the superficial gas velocity influence on the bed behavior, and how the bubble path configuration depends on the bed aspect ratio. The PIV measurements give us information on the location of the recirculation regions and the influence of the superficial gas velocity.Publicad
Exergy Optimization of a Moving Bed Heat Exchanger
The MBHE proposed can be analyzed as a crossflow heat exchanger where one of the phases is a moving granular medium. In the present work the exergy analysis of the MBHE is carried out over operation data of the exchanger obtained in two ways: a numerical simulation of the stationary problem and a simplified analysis. The numerical simulation is carried over the two steady state energy equations (fluid and solid), involving (for the fluid) the convection heat transfer to the solid and the diffusion term in the flow direction, and (for the solid) only the convection heat transfer to the fluid. The simplified analysis followed the well-known e-NTU method, taking the equipment as a crossflow heat exchanger with both fluids unmixed.Publicad
Bioenergy production in Central America: integration of sweet sorghum into sugar mills
This paper aims to evaluate the potential for electricity and ethanol production in Central America using sweet sorghum as an energy crop. Three scenarios were built to analyse sweet sorghum production in terms of the land where it can be cultivated: cropland, sugarcane land in fallow and land in continuous production (intercropping system). The land under permanent crops was not considered for this evaluation. We propose the integration of sweet sorghum into Central American sugar mills, by using the existing machinery to process it. The short growing period of sweet sorghum would allow the Combined Heat and Power (CHP) plants and distilleries to operate outside the sugarcane crushing season using sorghum bagasse and molasses as raw materials. This production could be performed 1 month before, and 1 month after the sugarcane season. Results indicate that by growing sweet sorghum on 5% of Central America's cropland, sorghum could supply around 10% of region's electricity demand. Thus, Central America could increase its CHP share of electricity supply from 4.4% to 5.6%. The increase in renewable electricity production would allow countries such as Guatemala, Honduras and Nicaragua to reduce fossil fuel bills by USD 517 million by using ethanol gasoline blends or USD$ 463 million by using ethanol diesel blends.This work was partially founded by the Spanish Agency for
International Development Cooperation (AECID) in the development of this research project.Publicad
Productivity of two cowpea cultivars in tobacco agroecosystems of Pinar del Río, Cuba
The objective of this research was to determine the productivity of INIFAT 93 and INIFAT 94 cultivars of cowpea (Vigna unguiculata (L.) Walp.) in tobacco agroecosystems in Pinar del Río. Between April and July 2019, field experiments were established in agricultural settings of Guane and San Juan y Martínez, characterized by a leached yellowish Ferralitic soil. Sowing was done manually at 0.60 m between rows and 0.15 m between plants. The evaluations were carried out at harvest time and growth variables (biomass), yield components and crop index were considered for each cultivar and agroecosystem. Higher biological productivity was achieved with INIFAT 94, although the differentiated response between cultivars, for biomass values, was more accentuated in San Juan and Martínez. Yield components were favored in INIFAT 94; while the lowest variability and highest efficiency in the conversion of economically useful biomass was obtained with INIFAT 93. The agricultural productivity of the INIFAT 94 cultivar exceeded that of INIFAT 93 by more than 25 % in the two agroecosystems, with values higher than 1.0 t/ha.El objetivo de la presente investigación fue determinar la productividad de los cultivares INIFAT 93 e INIFAT 94 de frijol caupí (Vigna unguiculata (L.) Walp.) en agroecosistemas tabacaleros de Pinar del Río. Durante el periodo abril – julio de 2019, se establecieron experimentos de campo en escenarios agrícolas de Guane y San Juan y Martínez, caracterizados por un suelo Ferralítico Amarillento lixiviado. La siembra se realizó de forma manual a una distancia de 0,60 m entre surcos y de 0,15 m entre plantas. Las evaluaciones se realizaron al momento de la cosecha y se consideraron variables de crecimiento (biomasa), componentes del rendimiento e índice de cosecha para cada cultivar y agroecosistema. Se alcanzó mayor productividad biológica con INIFAT 94, aunque la respuesta diferenciada entre los cultivares, para los valores de biomasa, fue más acentuada en San Juan y Martínez. Los componentes del rendimiento se favorecieron en INIFAT 94; mientras que, la menor variabilidad y mayor eficiencia en la conversión de biomasa económicamente útil se obtuvo con INIFAT 93. La productividad agrícola del cultivar INIFAT 94 excedió más del 25 % la de INIFAT 93 en los dos agroecosistemas, con valores superiores a 1,0 t/ha
Contribution of Candida biomarkers and DNA detection for the diagnosis of invasive candidiasis in ICU patients with severe abdominal conditions
Background: To assess the performance of Candida albicans germ tube antibody (CAGTA), (1???3)-ß-D-glucan (BDG), mannan antigen (mannan-Ag), anti-mannan antibodies (mannan-Ab), and Candida DNA for diagnosing invasive candidiasis (IC) in ICU patients with severe abdominal conditions (SAC).
Methods: A prospective study of 233 non-neutropenic patients with SAC on ICU admission and expected stay?=?7 days. CAGTA (cutoff positivity?=?1/160), BDG (=80, 100 and 200 pg/mL), mannan-Ag (=60 pg/mL), mannan-Ab (=10 UA/mL) were measured twice a week, and Candida DNA only in patients treated with systemic antifungals. IC diagnosis required positivities of two biomarkers in a single sample or positivities of any biomarker in two consecutive samples. Patients were classified as neither colonized nor infected (n?=?48), Candida spp. colonization (n?=?154) (low-grade, n?=?130; high-grade, n?=?24), and IC (n?=?31) (intra-abdominal candidiasis, n?=?20; candidemia, n?=?11).
Results: The combination of CAGTA and BDG positivities in a single sample or at least one of the two biomarkers positive in two consecutive samples showed 90.3 % (95 % CI 74.2–98.0) sensitivity, 42.1 % (95 % CI 35.2–98.8) specificity, and 96.6 % (95 % CI 90.5–98.8) negative predictive value. BDG positivities in two consecutive samples had 76.7 % (95 % CI 57.7–90.1) sensitivity and 57.2 % (95 % CI 49.9–64.3) specificity. Mannan-Ag, mannan-Ab, and Candida DNA individually or combined showed a low discriminating capacity.
Conclusions: Positive Candida albicans germ tube antibody and (1???3)-ß-D-glucan in a single blood sample or (1???3)-ß-D-glucan positivity in two consecutive blood samples allowed discriminating invasive candidiasis from Candida spp. colonization in critically ill patients with severe abdominal conditions. These findings may be helpful to tailor empirical antifungal therapy in this patient population
Intensive care adult patients with severe respiratory failure caused by Influenza A (H1N1)v in Spain
Introduction: Patients with influenza A (H1N1)v infection have developed rapidly progressive lower respiratory tract disease resulting in respiratory failure. We describe the clinical and epidemiologic characteristics of the first 32 persons reported to be admitted to the intensive care unit (ICU) due to influenza A (H1N1)v infection in Spain. Methods: We used medical chart reviews to collect data on ICU adult patients reported in a standardized form. Influenza A (H1N1)v infection was confirmed in specimens using real-time reverse transcriptase-polymerase-chain-reaction (RT PCR) assay. Results: Illness onset of the 32 patients occurred between 23 June and 31 July, 2009. The median age was 36 years (IQR = 31 - 52). Ten (31.2%) were obese, 2 (6.3%) pregnant and 16 (50%) had pre-existing medical complications. Twenty-nine (90.6%) had primary viral pneumonitis, 2 (6.3%) exacerbation of structural respiratory disease and 1 (3.1%) secondary bacterial pneumonia. Twenty-four patients (75.0%) developed multiorgan dysfunction, 7 (21.9%) received renal replacement techniques and 24 (75.0%) required mechanical ventilation. Six patients died within 28 days, with two additional late deaths. Oseltamivir administration delay ranged from 2 to 8 days after illness onset, 31.2% received high-dose (300 mg/day), and treatment duration ranged from 5 to 10 days (mean 8.0 +/- 3.3). Conclusions: Over a 5-week period, influenza A (H1N1)v infection led to ICU admission in 32 adult patients, with frequently observed severe hypoxemia and a relatively high case-fatality rate. Clinicians should be aware of pulmonary complications of influenza A (H1N1)v infection, particularly in pregnant and young obese but previously healthy persons
Melatonin Enhances Cisplatin and Radiation Cytotoxicity in Head and Neck Squamous Cell Carcinoma by Stimulating Mitochondrial ROS Generation, Apoptosis, and Autophagy
Head and neck cancer is the sixth leading cancer by incidence worldwide. Unfortunately, drug resistance and relapse are the
principal limitations of clinical oncology for many patients, and the failure of conventional treatments is an extremely
demoralizing experience. It is therefore crucial to find new therapeutic targets and drugs to enhance the cytotoxic effects of
conventional treatments without potentiating or offsetting the adverse effects. Melatonin has oncostatic effects, although the
mechanisms involved and doses required remain unclear. The purpose of this study is to determine the precise underlying
mitochondrial mechanisms of melatonin, which increase the cytotoxicity of oncological treatments, and also to propose new
melatonin treatments in order to alleviate and reverse radio- and chemoresistant processes. We analyzed the effects of
melatonin on head and neck squamous cell carcinoma (HNSCC) cell lines (Cal-27 and SCC-9), which were treated with 0.1, 0.5,
1, and 1.5mM melatonin combined with 8 Gy irradiation or 10 μM cisplatin. Clonogenic and MTT assays, as well as autophagy
and apoptosis, involving flow cytometry and western blot, were performed in order to determine the cytotoxic effects of the
treatments. Mitochondrial function was evaluated by measuring mitochondrial respiration, mtDNA content (RT-PCR), and
mitochondrial mass (NAO). ROS production, antioxidant enzyme activity, and GSH/GSSG levels were analyzed using a
fluorometric method. We show that high concentrations of melatonin potentiate the cytotoxic effects of radiotherapy and
CDDP in HNSCC, which are associated with increased mitochondrial function in these cells. In HNSCC, melatonin induces
intracellular ROS, whose accumulation plays an upstream role in mitochondria-mediated apoptosis and autophagy. Our
findings indicate that melatonin, at high concentrations, combined with cisplatin and radiotherapy to improve its effectiveness,
is a potential adjuvant agent.This study was partially supported by grants from the Ministerio
de Economía y Competitividad, Spain, and the FEDER
Regional Development Fund (nos. SAF2013-49019 and
SAF2017-85903), from the Instituto de Salud Carlos III (no.
CB/10/00238), and from the Consejería de Economía, Innovación,
Ciencia y Empleo, Junta de Andalucía (CTS-101)
The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in
operation since July 2014. This paper describes the second data release from
this phase, and the fourteenth from SDSS overall (making this, Data Release
Fourteen or DR14). This release makes public data taken by SDSS-IV in its first
two years of operation (July 2014-2016). Like all previous SDSS releases, DR14
is cumulative, including the most recent reductions and calibrations of all
data taken by SDSS since the first phase began operations in 2000. New in DR14
is the first public release of data from the extended Baryon Oscillation
Spectroscopic Survey (eBOSS); the first data from the second phase of the
Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2),
including stellar parameter estimates from an innovative data driven machine
learning algorithm known as "The Cannon"; and almost twice as many data cubes
from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous
release (N = 2812 in total). This paper describes the location and format of
the publicly available data from SDSS-IV surveys. We provide references to the
important technical papers describing how these data have been taken (both
targeting and observation details) and processed for scientific use. The SDSS
website (www.sdss.org) has been updated for this release, and provides links to
data downloads, as well as tutorials and examples of data use. SDSS-IV is
planning to continue to collect astronomical data until 2020, and will be
followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14
happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov
2017 (this is the "post-print" and "post-proofs" version; minor corrections
only from v1, and most of errors found in proofs corrected
Contribution of Candida biomarkers and DNA detection for the diagnosis of invasive candidiasis in ICU patients with severe abdominal conditions
BACKGROUND: To assess the performance of Candida albicans germ tube antibody (CAGTA), (1 → 3)-ß-D-glucan (BDG), mannan antigen (mannan-Ag), anti-mannan antibodies (mannan-Ab), and Candida DNA for diagnosing invasive candidiasis (IC) in ICU patients with severe abdominal conditions (SAC). METHODS: A prospective study of 233 non-neutropenic patients with SAC on ICU admission and expected stay ≥ 7 days. CAGTA (cutoff positivity ≥ 1/160), BDG (≥80, 100 and 200 pg/mL), mannan-Ag (≥60 pg/mL), mannan-Ab (≥10 UA/mL) were measured twice a week, and Candida DNA only in patients treated with systemic antifungals. IC diagnosis required positivities of two biomarkers in a single sample or positivities of any biomarker in two consecutive samples. Patients were classified as neither colonized nor infected (n = 48), Candida spp. colonization (n = 154) (low-grade, n = 130; high-grade, n = 24), and IC (n = 31) (intra-abdominal candidiasis, n = 20; candidemia, n = 11). RESULTS: The combination of CAGTA and BDG positivities in a single sample or at least one of the two biomarkers positive in two consecutive samples showed 90.3 % (95 % CI 74.2–98.0) sensitivity, 42.1 % (95 % CI 35.2–98.8) specificity, and 96.6 % (95 % CI 90.5–98.8) negative predictive value. BDG positivities in two consecutive samples had 76.7 % (95 % CI 57.7–90.1) sensitivity and 57.2 % (95 % CI 49.9–64.3) specificity. Mannan-Ag, mannan-Ab, and Candida DNA individually or combined showed a low discriminating capacity. CONCLUSIONS: Positive Candida albicans germ tube antibody and (1 → 3)-ß-D-glucan in a single blood sample or (1 → 3)-ß-D-glucan positivity in two consecutive blood samples allowed discriminating invasive candidiasis from Candida spp. colonization in critically ill patients with severe abdominal conditions. These findings may be helpful to tailor empirical antifungal therapy in this patient population
- …