Effect of Ozone on Postharvest Quality of Persimmon

ABSTRACT:  The effect of gaseous ozone exposure on the quality of persimmon picked at 2 different harvest dates was evaluated. Fruit from both harvests were continuously exposed to 0.15 ppm (vol/vol) of ozone for 30 d at 15 °C, 90% relative humidity (RH). Then, fruit were submitted to astringency removal treatment (24 h at 20 °C, 98% CO₂) and stored for 7 d at 20 °C (90% RH) in order to simulate shelf-life period. The most important disorder was flesh softening, which took place when fruit were transferred from 15 °C to shelf-life conditions. In the 2nd harvest, where the fruit were harvested with lower firmness, ozone maintained firmness over commercial limits even after 30 d at 15 °C plus shelf-life. Ozone-treated fruit showed the highest values of weight loss, coinciding with the maximum electrolyte leakage (EL) percentage. Ozone did not affect color index (CI), ethanol, total soluble solids (TSS), or pH. Unremarkable differences in acetaldehyde were observed between fruit submitted to ozone treatment and control fruit. No phytotoxic injuries in tissues were observed in ozone-treated fruit.     

Water Treatment Units Residence-Time Distributions as Probabilistic Functions

A probabilistic approach to obtain theoretical residence-time distribution (RTD) functions for series of reactors with possible stagnation, bypassing, and recycle is presented. It is shown that most known RTD functions can be obtained from probability arguments alone, thus avoiding abstract Laplace transform mathematical techniques and providing additional physical insight. Several new RTD models for reactors in series are derived, based exclusively on using the binomial probability distribution to describe the passage of a particle through the treatment train with bypassing and stagnation possible at each individual reactor. The proposed RTD models are validated with travel time computer simulation of a large number of particles through the series of reactors. A MSExcel based computer procedure was programmed to obtain the nonideal flow parameters by minimizing the squared sum of the differences between tracer test data and the derived unit’s RTD function. The least squares parameter estimation procedure was used to fit theoretical RTDs to tracer data collected from real water treatment units with different hydraulic behavior at two locations in Mexico.     

Effect of phosphate binders on oxidative stress and inflammation markers in hemodialysis patients

It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n=17) or CA (n=14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor α, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor α and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD.     

Molecular Subtyping of Invasive Breast Cancer Using a PAM50-Based Multigene Expression Test-Comparison with Molecular-Like Subtyping by Tumor Grade/Immunohistochemistry and Influence on Oncologist’s Decision on Systemic Therapy in a Real-World Setting

In intermediate risk hormone receptor (HR) positive, HER2 negative breast cancer (BC), the decision regarding adjuvant chemotherapy might be facilitated by multigene expression tests. In all, 142 intermediate risk BCs were investigated using the PAM50-based multigene expression test Prosigna® in a prospective multicentric study. In 119/142 cases, Prosigna® molecular subtyping was compared with local and two central (C1 and C6) molecular-like subtypes relying on both immunohistochemistry (IHC; HRs, HER2, Ki-67) and IHC + tumor grade (IHC+G) subtyping. According to local IHC, 35.4% were Luminal A-like and 64.6% Luminal B-like subtypes (local IHC+G subtype: 31.9% Luminal A-like; 68.1% Luminal B-like). In contrast to local and C1 subtyping, C6 classified >2/3 of cases as Luminal A-like. Pairwise agreement between Prosigna® subtyping and molecular-like subtypes was fair to moderate depending on molecular-like subtyping method and center. The best agreement was observed between Prosigna® (53.8% Luminal A; 44.5% Luminal B) and C1 surrogate subtyping (Cohen’s kappa = 0.455). Adjuvant chemotherapy was suggested to 44.2% and 88.6% of Prosigna® Luminal A and Luminal B cases, respectively. Out of all Luminal A-like cases (locally IHC/IHC+G subtyping), adjuvant chemotherapy was recommended if Prosigna® testing classified as Prosigna® Luminal A at high / intermediate risk or upgraded to Prosigna® Luminal B.     

Serum Tocopherol Levels in Healthy Workers

The serum tocopherol levels were determined on 923 workers (18–62 years of age) from the textile, chemical and metallurgical industries. Tocopherol levels varied between 0,20 and 1,86 mg per 100 ml serum, the mean value being 0,77 ± 0,01 mg per 100 ml, but in 148 subjects (16%) concentrations under 0,5 mg per 100 ml were found. For women the average was significantly (p < 0,05) lower than that for men (0,75 ± 0,02 compared to 0,79 ± 0,01) and the prevalence of levels below 0,5 mg per 100 ml greater (18,4% compared to 12,6%). Independent of sex the serum tocopherol level increased with age (from 0,59 ± 0,02 under 26 years, to 0,87 ± 0,05 mg per 100 ml for the group over 55 years, p < 0,001). By grouping the persons according to the tocopherol levels (A = up to 0,5 mg per 100 ml; B = 0,51–1,0 and C = over 1,0 mg per 100 ml) and by calculating for each group the average values of the daily fat intake (supplied especially by sunflower oil) a relationship was found between the two series of values, but overall this did not reach statistical significance.     

Influence of air drying temperature on kinetics,physicochemical properties,total phenolic content and ascorbic acid of pears

This study was conducted to evaluate quality and structural changes in parallelepipedic pieces of pears during convective drying at different air temperatures (30–70 °C).Submitted to atmospheric O₂ conditions, ascorbic acid deterioration demonstrated first-order kinetic behaviour and was found to depend on air temperature and pear moisture content. Loss of ascorbic acid content increased with increasing air temperature. Possible explanation could be the irreversible oxidative reaction occurring during drying. Phenol content degradation fitted a pseudo first-order reaction and was significantly influenced by air temperature.Variations in bulk density, shrinkage and porosity essentially depended on changes in moisture content. Porosity exhibited a nonlinear variation with respect to moisture content. Volume change showed, as expected, a linear variation with moisture content. Drying temperature significantly induced the increase of a* and b* colorimetric parameters due to non-enzymatic browning reaction, which turned the samples more reddish and yellow when the temperature rose.