An approximate analytical solution to solve the nonlinear diffusion-reaction transport problem has been developed. The system considered is a liquid membrane where the facilitated transport or ...carrier-mediated transport occurs. The approximate analytical solution methodology is based on the Taylor series expansion of the reaction rate around the two limiting surfaces of the liquid membrane. The methodology leads to analytical expressions for the concentration profiles of the species in the membrane. Predictions for the facilitation factor have been obtained for a wide range of Damköhler number values, from the physical diffusion regime to the equilibrium chemical reaction regime, considering cases of equal and unequal carrier and complex diffusivities and cases of zero and nonzero downstream solute concentration. For the example presented here, the difference between the approximate predictions and those obtained from the numerical solution is not greater than 5.0%.
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IJS, KILJ, NUK, PNG, UL, UM
ABSTRACT INTRODUCTION Tuberculosis is the second leading cause of infectious-disease death worldwide, after AIDS. Most tuberculosis patients in Cuba have pulmonary TB and recovery rates are high. ...When TB chemotherapy fails, the most common adverse outcome is death. OBJECTIVE Determine survival patterns in a cohort of pulmonary TB patients in Cuba. METHODS A retrospective cohort study was conducted of pulmonary TB patients who were notified and treated in Cuba in 2009 and 2010. Time elapsed between diagnosis and death was examined. Patient survival was analyzed with the Kaplan–Meier method and comparisons were made with the log-rank estimator; an adjusted Cox model was used to analyze risk of death. RESULTS The study included 1339 patients, of whom 71.7% were aged 25–64 years and 77.4% were men. Infectious pulmonary tuberculosis was the most common form (75.6%). Only a small number of patients (5.7%) presented TB/HIV coinfection. Ninety-four deaths were reported, 55% during the first 60 days of treatment. Lower survival rates were observed among men (HR 1.87, 95% CI 1.02–3.45), patients coinfected with HIV/AIDS (HR 6.25, 95% CI 3.46–11.31), and patients aged ≥48 years (HR 3.93, 95% CI 2.41–6.40). CONCLUSION The preponderance of deaths early in TB treatment course may be related to diagnostic and/or treatment delays. Older age at diagnosis, male sex and TB/HIV coinfection increase risk of death.
An approximate solution for the problem of diffusion-reaction in an isothermal catalyst pellet when coke deposition occurs was developed. The approximation is based on the linearization of reaction ...terms, producing analytical expressions to evaluate concentration profiles inside the pellet and the effectiveness factor. The approximate solution can be extended to any form of reaction rate functionalities for the main and coking reactions. Coke formation from reactants (parallel coking) or products (consecutive coking) and deactivation functions dependent on the coke content are considered in pellets with slab, cylindrical and spherical geometry.In this work, first-order kinetics for the main and coking reactions and linear and exponential deactivation functions were evaluated. The approximate predictions of the concentration profiles and the effectiveness factors were compared with results obtained by the complete numerical solution. A good agreement was found for both parallel and consecutive coking, including the cases when low and high intra pellet diffusion resistances are present.
The methodologies for online continuous monitoring, classification, and diagnosis of induction motors are experimenting changes, mainly, due to the current affordability of infrared cameras ...incorporated in industrial applications. It is required that the procedures and techniques have low computational cost and automated behavior in order to be reliable as online failure detectors. To address these requirements, a methodology based on infrared imaging is proposed. First, the infrared thermography is capture and processed to obtain its thermal distribution information. Second, the histogram features, standard deviation and entropy, are extracted. Finally, a machine learning based in nearest neighbor algorithm is used to perform a fault classification and diagnosis. To demonstrate the efficiency of the proposed methodology, this paper presents the failure analysis of three condition: two, one and half level of broken rotor bar fault in an induction motor.
Huntington's disease (HD) is a hereditary disease of the central nervous system. Its molecular diagnosis has allowed predictive and prenatal diagnosis to be done, and it is now a model for the study ...of the ethical, legal, and social problems arising from the diagnosis of such diseases.
This study explores the knowledge and attitudes of a group of Mexican specialists regarding the disease and its diagnosis. A self-administered, 30-item multiple-choice questionnaire was completed anonymously by neurologists, psychiatrists, and psychologists.
Fifty-five percent of the professionals had experience with HD patients, 59% claimed to know the hereditary risks, and 20% answered incorrectly concerning the risks. Neurologists had the most exposure to HD; 74% acknowledged the existence of predictive diagnosis, although only 10% knew the international guidelines for testing. Eighty-six percent of the participants recommended predictive diagnosis, the reasons being: 55%, if the patients considered having offspring; 41%, for the patient's professional reasons; 6%, if a treatment was available, and 12% did not answer. In cases in which the patient wanted to have offspring, 38% thought that this should be avoided. Thirty-six percent of the subjects considered prenatal diagnosis justified in a couple with a carrier, and 51% justified abortion for affected fetuses.
Genetic counseling and predictive diagnosis in Mexico must be the responsibility of genetics units and specialists who are aware of inheritance risks and of guidelines for HD programs. The number of patients requiring such attention is increasing rapidly
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IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Rhammnus alaternus seedlings were irrigated with 0, 70 mM and 140 mM salt water in greenhouse conditions to study the effect of the drench application of 30 mg-paclobutrazol (PBZ) on the salt stress ...response. Overall, PBZ and salinity reduced growth and development in a cumulative way, producing plants that were too small, especially at the highest saline concentration. PBZ-treated plants showed less marginal and tip necrosis, defoliation and mortality than nontreated, especially in 140 mM-treated plants. PBZ increased the relative chlorophyll content in leaves in both saline and nonsaline conditions. Salinity significantly reduced stomatal conductance in plants not treated with PBZ. PBZ increased stomatal conductance from 37.2 to 72.3 mmol m-2 s-1 in the 70 mM-salt treatment, and from 47.8 to 68.0 in the 140 mM-salt treatment. Salinity reduced both the relative water content and water potential, but maintained turgor potential in PBZ-treated and nontreated plants as a consequence of osmotic adjustment. Although the degree of osmotic adjustment was very similar, the osmotically active compounds accumulated in each type of treatment (PBZ treated and nontreated plants) are probably different. In both saline treatments, the salt content of the leaching water increased when plants were treated with PBZ. These findings suggest that PBZ reduced saline stress symptoms and mortality in stressed plants by promoting organic solutes synthesis and by reducing the availability of saline ions in the medium (greater leaching action).
Pumpkin pulp is the main waste generated by pumpkin seed growers. This agro‐industrial waste is a valuable source of bioactive compounds, especially carotenoids (β‐carotene, α‐carotene, and lutein), ...which exhibit a broad spectrum of health‐promoting effects. In this study, vegetable oils (canola, corn, and soybean oil) were used as green solvent alternatives to conventional organic solvents for carotenoid extraction from dried pumpkin pulp (DPP) waste. The highest carotenoid extraction yield (CEY) was obtained with canola oil, at a 1:10 DPP/oil ratio. Response surface methodology (RSM) was used to optimize the extraction process parameters (temperature, time, and stirring rate) through a Box‐Behnken design (BBD) maximizing CEY in canola oil. The extraction temperature and stirring rate were found to have a significant linear and quadratic effect, respectively, on CEY. Optimum conditions were achieved at 21.8 min, 250 rpm, and 60°C. Under these optimized conditions, the estimated value for CEY was 378.1 µg β‐carotene equivalents/g of DPP, corresponding to 61.6% of the total carotenoid content present in the DPP. In contrast, the observed experimental value was 373.2 µg β‐carotene equivalents/g of DPP (61.2%). The experimental value was very close to the estimated value, which verifies the model's adequacy and fit. This study shows an alternative method to extract carotenoids from DPP with canola oil, obtaining an oil naturally enriched with carotenoids that could be used as a potential functional ingredient in the development of food, cosmetics, and medicinal products.
Practical Application
Pumpkin by‐products are a potential carotenoid source. Vegetable oil can be used as an alternative solvent for carotenoid extraction from pumpkin residues to obtain an enriched carotenoid oil that can be used to formulate food products.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
