A mathematical model was developed from experimental measurements to describe the evolution of the O 2 , CO 2 and ethylene in a modified atmosphere packaging system for Cavendish bananas. The respiration and ethylene production in the fruits were experimentally obtained from a closed system method and then represented by Michaelis-Menten equations of enzyme kinetics. The gas transfer through the packaging was described by a Fick's diffusion equation, and the temperature dependence was represented based on the Arrhenius law. The model was validated by packaging the fruit in perforated bags of polypropylene and low density polyethylene at 12°C for a period of 8 days. With the developed model it was possible to satisfactorily describe the experimental evolution of the gas content in the headspace of the packages, obtaining coefficients of determination (R 2 ) of 0.93 for the O 2 levels, 0.90-0.91 for the CO 2 levels, and 0.89-0.93 for the ethylene levels.

The period following heart failure hospitalization (HFH) is a vulnerable time with high rates of death or recurrent HFH.OBJECTIVE To evaluate clinical characteristics, outcomes, and treatment response to vericiguat according to prespecified index event subgroups and time from index HFH in the Vericiguat Global Study in Subjects With Heart Failure With Reduced Ejection Fraction (VICTORIA) trial. DESIGN, SETTING, AND PARTICIPANTSAnalysis of an international, randomized, placebo-controlled trial. All VICTORIA patients had recent (<6 months) worsening HF (ejection fraction <45%). Index event subgroups were less than 3 months after HFH (n = 3378), 3 to 6 months after HFH (n = 871), and those requiring outpatient intravenous diuretic therapy only for worsening HF (without HFH) in the previous 3 months (n = 801). Data were analyzed between May 2, 2020, and May 9, 2020.INTERVENTION Vericiguat titrated to 10 mg daily vs placebo. MAIN OUTCOMES AND MEASURESThe primary outcome was time to a composite of HFH or cardiovascular death; secondary outcomes were time to HFH, cardiovascular death, a composite of all-cause mortality or HFH, all-cause death, and total HFH. RESULTS Among 5050 patients in the VICTORIA trial, mean age was 67 years, 24% were women, 64% were White, 22% were Asian, and 5% were Black. Baseline characteristics were balanced between treatment arms within each subgroup. Over a median follow-up of 10.8 months, the primary event rates were 40.9, 29.6, and 23.4 events per 100 patient-years in the HFH at less than 3 months, HFH 3 to 6 months, and outpatient worsening subgroups, respectively. Compared with the outpatient worsening subgroup, the multivariable-adjusted relative risk of the primary outcome was higher in HFH less than 3 months (adjusted hazard ratio, 1.48; 95% CI, 1.27-1.73), with a time-dependent gradient of risk demonstrating that patients closest to their index HFH had the highest risk. Vericiguat was associated with reduced risk of the primary outcome overall and in all subgroups, without evidence of treatment heterogeneity. Similar results were evident for all-cause death and HFH. Addtionally, a continuous association between time from HFH and vericiguat treatment showed a trend toward greater benefit with longer duration since HFH. Safety events (symptomatic hypotension and syncope) were infrequent in all subgroups, with no difference between treatment arms.CONCLUSIONS AND RELEVANCE Among patients with worsening chronic HF, those in closest proximity to their index HFH had the highest risk of cardiovascular death or HFH, irrespective of age or clinical risk factors. The benefit of vericiguat did not differ significantly across the spectrum of risk in worsening HF.

La poda de tallos y racimos florales afecta la producción de frutos de lulo (Solanum quitoense var. septentrionale) Effect of stem and floral cluster pruning on fruit production of lulo plants (Solanum quitoense var. septentrionale

RESUMENEl banano bocadillo es considerado uno de los productos hortofrutícolas promisorios exportables de Colombia, no obstante, es un producto altamente perecedero, por lo anterior es necesaria la evaluación de tecnologías de bajo costo que aumenten la conservación de estos frutos. El permanganato de potasio (KMnO 4 ) ha mostrado ser una herramienta eficaz en la conservación de diferentes frutos debido a que oxida al etileno. El objetivo de este estudio fue evaluar el efecto del KMnO 4 en la conservación de frutos de banano bocadillo, para lo cual se utilizó un diseño en bloques completos al azar con arreglo factorial de 3 × 3 + 1, donde los bloques correspondieron a los tipos de arcillas (montmorillonita, caolinita, vermiculita y zeolita), el primer factor consistió en las dosis de KMnO 4 (0,5%; 1,0% y 1,5% con base en el peso fresco de los frutos) y el segundo factor fueron las dosis de arcilla (0,5%; 1,0% y 1,5%) usada como carrier del KMnO 4 , más un testigo absoluto, los frutos fueron almacenados durante 16 días a temperatura ambiente y periódicamente se midió el índice de color (IC), sóli-dos solubles totales (SST), pérdida de peso, firmeza, acidez total titulable (ATT) y relación de madurez (RM). Los resultados obtenidos muestran que la mezcla de 1% de arcilla + 1,5% de KMnO 4 favoreció la conservación de bananito, debido a que presentó menor IC (-0,64); menores SST (12,08 °Brix), mayor firmeza (70,65 N) y menor RM (83,67). Por lo tanto, existe un efecto favorable en la conservación de los frutos de bananito cuando el KMnO 4 se encuentra en mayor proporción con respecto a su carrier.Conservación del fruto de banano bocadillo (Musa AA Simmonds) con la aplicación de permanganato de potasio (KMnO 4 ) Conservation of baby banana (Musa AA Simmonds) fruits with the application of potassium permanganate (KMnO 4 )

This article presents a methodology for detection of high impedance faults (HIF). HIF occurs when e.g. a cable makes contact with objects of high electric resistance, resulting in a nonsignificant increase in current. Such faults cannot be detected by traditional protection devices that operate due to overcurrent. The developed methodology is based on making use of variables from a power quality meter (PQM), such as harmonic and sequence components of the currents measured at a substation. Such variables compose descriptors for decision making in artificial neural networks (ANN). In order to test the proposed method HIF events were simulated as well as other common network events using the ATP software. The proposed framework is part of a HIF detection system to be implemented in a substation of an electric utility in the state of São Paulo.

Plantulas de tomate.Foto: Álvarez-Herrera.Etileno y retardantes de la maduración en la poscosecha de productos agrícolas. Una revisión Ethylene and maturation retardants in the postharvest of perishable horticultural products. A review RESUMENEl etileno es la hormona vegetal responsable de regular diferentes procesos durante la maduración de productos agrícolas, llevando a procesos de senescencia y finalmente, pérdida de valor nutricional y comercial. A través del tiempo se han desarrollado diversos retardantes químicos de la maduración para disminuir los efectos negativos del etileno en la poscosecha, los cuales actúan en las etapas de biosíntesis (aminoetoxi-vinil-glicina (AVG) y ácido aminooxiacético (AOA), acción/señalización (1-MCP)) y sales de plata como nitrato y tiosulfato de plata (STS) y compuestos que oxidan al etileno de la atmósfera (permanganato de potasio (KMnO 4 )). En esta revisión se describen las características principales de cada uno de los retardantes de madurez mencionados, además, se analiza con estudios científicos, el efecto que tienen estos retardantes sobre los cambios moleculares, fisiológicos, químicos y físicos durante la poscosecha de frutos, hortalizas y especies ornamentales.

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