Hydrogen and wood-burning stoves.

Wood-burning stoves, in Kenya and Mexico, are reviewed. With a Kenyan stove, burning charcoal, only 24% of the energy released reached the cooking pot. Initially, the proportion of CO in the leaving gases was 3%. Indoor concentrations of particulate matter (less than 2.5 µm diameter) can be abnormally high near a stove. Decarbonization, by using H2, is facilitated by a distribution system. Replacement by H2 would ultimately rest upon wind or water power, or it being a by-product in the production of heavier hydrocarbons from CH4. The averaged burning rate in the Kenyan stove was 10 kW, over 20 min, with an initial peak value of about 30 kW. A possible replacement is a hob, composed of an array of small diameter H2 jet flames. As an example, combustion of a 2 mm internal diameter H2 jet flame, with a H2 exit velocity of 27.2 m s-1, would release 0.84 kW. Bearing in mind its improved efficiency, a single compact hob with an array of about 10 jets would suffice. A difficulty is the low mass-specific energy of H2. H2 has a high acoustic velocity, and both high velocity subsonic combustion and blending with natural gas are briefly discussed. This article is part of the theme issue 'Developing resilient energy systems'.

A comparative study of radiation models on propane jet fires based on experimental and computational studies.

Radiation as a consequence of jet fires is one of the significant parameters in process industry events. In the present work, the open field vertical propane jet fire was studied via experimental and computational fluid dynamics (CFD). The predicted values of radiation were verified at three locations in the horizontal direction from the jet fire. In the simulation section, four radiation models of Monte Carlo (MC), P-1, Discrete Transfer (DT), and Rosseland were applied to find the fine model for simulating the jet fire. Shear Stress Transport (SST) and Eddy Dissipation Concept (EDC) models are employed for combustion and turbulence, respectively. The estimated data by the simulation demonstrated that the MC radiation is better than the other models with an average error of 5% for predicted incident radiation from the jet flame axis. Also, the P-1 radiation model had an above 65% error at around the jet fire, but due to the error of less than 15% estimated by MC and DT models, these radiation models could simulate the jet flame radiation. The simulation outcomes proved that the Rosseland radiation model is not applicable owing to a lack of accurate temperature prediction.

Frequency of polymorphisms pro198leu in GPX-1 gene and ile58thr in MnSOD gene in the altitude Ecuadorian population with bladder cancer.

Bladder cancer represents 8% of all malignancies diagnosed in men and 3% in women. The risk factors for developing bladder cancer, including the incidence rate, morbidity, and mortality, vary according to the ethnic group, exposition rate at work, age, gender, and tobacco consumption. Moreover, there is a risk of developing this carcinoma due to dietary conditions, demonstrating that certain enzymes neutralize oxidative compound derivative of carcinogens, which if not degraded, accumulate in the body and destroy epithelial cells of the bladder, causing an increase in the risk of developing this disease. The detoxifying enzymes inactivate dangerous chemical compounds and anions for the cell; that is, why it is important to know if the polymorphisms pro198leu in GPX-1 and ile58thr in MnSOD are associated with bladder cancer. In this study, 120 individuals were analyzed as controls and 97 individuals with previously diagnosed bladder cancer. In the case of polymorphism pro198leu, highly significant differences were observed and individuals with this polymorphism presented a probability of developing bladder cancer 3.8 times greater than controls (OR = 3.8; 95% CI 2.16-6.78; p < 0.001). No significant differences in polymorphism ile58thr of MnSOD gene occurred when we compared the study population (OR = 2.1; 95% CI 1.26-3.49; p > 0.05). The results indicate that polymorphism of GPX-1 gene influences the risk of developing bladder cancer in the Ecuadorian population, suggesting that more research on detoxifying genes in bladder cancer should be conducted.

Analysis of deep learning neural network combined with experiments to develop predictive models for a propane vertical jet fire.

Fires are important responsible factors to cause catastrophic events in the process industries, whose consequences usually initiate domino effects. The artificial neural network has been shown to be one of the rapid methods to simulate processes in the risk analysis field. In the present work, experimental data points on jet fire shape ratios, defined by the 800 K isotherm, have been applied for ANN development. The mass flow rates and the nozzle diameters of these jet flames have been considered as input dataset; while, the jet flame lengths and widths have been collected as output dataset by the ANN models. A Bayesian Regularization algorithm has been chosen as the three-layer backpropagation training from Multi-layer perceptron algorithm. Then it has been compared with a Radial based functions algorithm, based on single hidden layer. The optimized number of neurons in the first and second hidden layers of the MLP algorithm, and in the single hidden layer of the RBF algorithm has been found to be twenty and fifteen, respectively. The best MSE validation performance of MLP and RBF networks has been found to be 0.00286 and 0.00426 at 100 and 20 epochs, respectively.

Corrigendum to "Analysis of deep learning neural network combined with experiments to develop predictive models for a propane vertical jet fire" [Heliyon 6 (11) (November 2020) Article e05511].

[This corrects the article DOI: 10.1016/j.heliyon.2020.e05511.].

Complete sequence of the ANKK1 gene in Mexican-Mestizo individuals with obesity, with or without binge eating disorder.

BACKGROUND: The aim of this study was to investigate if Mexican-Mestizo individuals with obesity, with or without binge eating disorder (BED), exhibited mutations or other type of genetic variants in the sequence of ANKK1. SUBJECTS AND METHODS: Fifty unrelated individuals (21-53 years of age) with obesity, of Mexican-Mestizo ethnic origin were included; 25 of them had BED and 25 presented obesity without BED. The diagnosis of BED was based on criteria proposed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Besides, we also analyzed 100 individuals with normal body mass index. DNA from blood leukocytes was amplified by the polymerase chain reaction and all exons of ANKK1 were sequenced. RESULTS: After ANKK1 sequencing we did not find any mutations; however, we observed various polymorphisms. One polymorphism, rs4938013 in exon 2 showed an association with obesity, whilst rs1800497 (also known as Taq1A) in exon 8, showed an association with BED (P = 0.020). Remarkable, for this study, the number of individuals for both polymorphisms for and additive model was sufficient to derive strong statistical power (80%, with a P < 0.05). CONCLUSIONS: To our knowledge, this constitutes the first report where the complete sequences of ANKK1 has been analyzed in individuals with obesity, with or without BED. No mutations were found; however, one polymorphism was associated with obesity, with or without BED, and another one was associated with BED.

Discordancia entre pruebas de susceptibilidad genotípicas y fenotípicas para tuberculosis en Cali, Colombia: un reto en la práctica clínica / Discordance between genotypic and phenotypic susceptibility tests for tuberculosis in Cali, Colombia: a challenge in the clinical practice

INTRODUCCIÓN: La detección de patrones de resistencia de Mycobacterium tuberculosis se basa en pruebas de susceptibilidad fenotípicas y genotípicas. Los resultados discordantes entre ellas son un desafío clínico para el manejo de pacientes con tuberculosis resistente a fármacos. OBJETIVO: Evaluar la concordancia entre pruebas fenotípicas y moleculares en pacientes con tuberculosis resistente a fármacos atendidos en una institución de Cali, Colombia. MATERIALES Y MÉTODOS: Se realizó un estudio transversal en el que se obtuvo el perfil de sensibilidad fenotípico de cultivos de micobacterias y la susceptibilidad genotípica con las pruebas moleculares Xpert-MTB/ RIF® o Genotype-MDRTBplus ®. Se evaluó el porcentaje de resistencia y porcentaje de acuerdo entre los resultados de las pruebas fenotípicas y genotípicas. Se estimó un coeficiente de kappa de Cohen (κ) para cada tipo de resistencia según la prueba utilizada. RESULTADOS: Se incluyeron 30 casos con resultados de pruebas genotípicas y fenotípicas. Las pruebas fenotípicas detectaron resistencia a fármacos de primera línea en 29/30 casos, mientras que las moleculares detectaron la resistencia en todos los casos evaluados. El porcentaje de resistencia a rifampicina detectado entre la prueba fenotípica y Genotype-MDRTBplus ® &e 61,5% (acuerdo global 41,1%, κ = 0,40, p = 0,96), mientras que el porcentaje de resistencia detectado con Xpert-MTB/RIF® fue 100% (acuerdo global 81,82%, κ: 0,00, p < 0,001) para este mismo medicamento. El porcentaje de resistencia a isoniacida detectado entre la prueba fenotípica y Genotype-MDRTBplus ® fue 94,4% (acuerdo global 89,47%, κ: -0,055 p = 0,59). CONCLUSIONES: La discordancia entre los resultados de las pruebas genotípicas y fenotípicas es posible, por lo que es importante usar e interpretar ambos tipos de pruebas de manera complementaria en el diagnóstico de la resistencia a fármacos de primera línea en la infección por M. tuberculosis.

BACKGROUND: The detection of Mycobacterium tuberculosis resistance patterns is based on phenotypic and genotypic susceptibility tests. The discordant results between them are a clinical challenge for the management of patients with drug-resistant tuberculosis. Aim: To evaluate the concordance between phenotypic and molecular tests in patients with drug-resistant tuberculosis treated in an institution in Cali, Colombia. METHODS: A cross-sectional study was conducted. A phenotypic sensitivity profile was obtained from mycobacterial cultures. The genotypic susceptibility was obtained with Xpert-MTB/ RIF® or Genotype-MDRTBplus ®. The percentage of resistance and percentage of agreement between the results of the phenotypic and genotypic tests were evaluated. A Cohen's kappa coefficient (κ) was estimated for each type of resistance according to the test used. RESULTS: A total of 30 cases with both genotypic and phenotypic testing were included. The phenotypic tests detected resistance to first-line drugs in 29/30 cases, while the molecular tests detected resistance in all the cases evaluated. The percentage of resistance detected between Genotype-MDRTBplus® and the phenotypic test for rifampicin was 61.5% (overall agreement 41.1%, κ = 0.40, p = 0.96), while the percentage of resistance detected with XpertMTB/RIF® was 100% (overall agreement 81.82%, κ: 0.00, p < 0.001) for this same drug. Resistance to isoniazid detected by both types of tests was 94.4% (overall agreement 89.47%, κ: -0.055 p = 0.59). CONCLUSIONS: Discordance between the results of genotypic and phenotypic tests is possible, so it is important to use and interpret both types of tests in a complementary way in the diagnosis of resistance to first-line drugs in M. tuberculosis infection.

Targeted delivery of small interfering RNA to colon cancer cells using chitosan and PEGylated chitosan nanoparticles.

Small interfering RNA (siRNA) molecules specifically target messenger RNA species, decreasing intracellular protein levels. ß-Catenin protein concentrations are increased in 70-80% of colon tumors, promoting tumor progression. Chitosan exhibits low levels of toxicity and can be transported across mucosal membranes; therefore, our objective was to develop chitosan and poly(ethylene glycol)-grafted (PEGylated) chitosan nanoparticles, 100-150nm in diameter, encapsulating anti-ß-catenin siRNA for transfection into colon cancer cells. Encapsulation efficiencies up to 97% were observed. Confocal microscopy visualized the entry of fluorescently-tagged siRNA into cells. Western blot analysis showed that both chitosan and PEGylated chitosan nanoparticles containing anti-ß-catenin siRNA decreased ß-catenin protein levels in cultured colon cancer cells. These results indicate that nanoparticles made with chitosan and PEGylated chitosan can successfully enter colon cancer cells and decrease the level of a protein that promotes tumor progression. These or similar nanoparticles may prove beneficial for the treatment of colon cancer in humans.

Domino effect in chemical accidents: main features and accident sequences.

The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident scenario, the type of accident, the materials involved, the causes and consequences and the most common accident sequences. The analysis showed that the most frequent causes are external events (31%) and mechanical failure (29%). Storage areas (35%) and process plants (28%) are by far the most common settings for domino accidents. Eighty-nine per cent of the accidents involved flammable materials, the most frequent of which was LPG. The domino effect sequences were analyzed using relative probability event trees. The most frequent sequences were explosion→fire (27.6%), fire→explosion (27.5%) and fire→fire (17.8%).

Estudio de la susceptibilidad al efecto citolítico debido al factor de necrosis tumoral-alfa (TNF-Ó), en distintas líneas celulares derivadas de neoplasias pulmonares humanas / Study of the susceptibility to the cytolytic effect due to tumor necrosis factor alpha (TNF-A) in different cell lines derived from human lung neoplasms

En este trabajo, se emplearon ocho distintas líneas de células tumorales que representan las extirpes histológicas más frecuentes del cáncer pulmonar a nivel mundial, para determinar su susceptibilidad a la lisis inducida por el factor de necrosis tumoral-alfa recombinante (rTNF-Ó), así como la expresión membranal de receptores tipo I(p55-60) y tipo II(p75-80) para esta molécula. El efecto citotóxico del TNF se estudió mediante un ensayo de liberación de marca radiactiva (51 Cr), mientras que la determinación de receptores se llevó a cabo por inmunocitoquímica, empleando anticuerpos específicos para cada receptor. En general, los resultados muestran que existe una gran heterogeneidad en la población celular que constituye cada línea tumoral, ya que en ningún caso se obtuvo una citotoxicidad del 100 por ciento. De las líneas celulares estudiadas, el adenocarcinoma SK-LU-1 y el carcinoma epidermoide SK-MES-1 mostraron el mayor grado de susceptibilidad al TNF-Ó, ya que se lisó alrededor del 50 por ciento de la población al emplear 1U del factor; sin embargo, a la mayor concentración del TNF, la lisis sólo fue del 65 y 55 por ciento, respectivamente. Otras líneas celulares representadas por tres ca epidermoide (1.3.11, 1.3.15 y Calu-1) y un adenocarcinoma (A-427), presentaron muy poca susceptibilidad a la lisis; en cambio, los ca de células pequeñas (NCI-H69 y NCI-H128) fueron completamente refractarios al efecto biológico de este factor. Con respecto ala expresión membranal de los receptores para el TNF-Ó, todas las líneas celulares estudiadas poseen el receptor tipo I (TNFR-I) y ninguna muestra el receptor tipo II (TNFR-II). En conjunto, estos resultados nos indican que la mayoría de las neoplasias pulmonares no son susceptibles al efecto citotóxico del TNF-Ó, característica que no está asociada a la falta de expresión del receptor tipo I, el cual es considerado responsable de esta acción biológica del TNF-Ó. Por lo expresado anteriormente, es necesario determinar cuáles son los mecanismos de evación que presentan estos carcinomas al efecto citolítico del TNF, si es que se pretende emplear esta importante molécula con fines terapéuticos