Evaluation of the Native Killer Yeasts against the Postharvest Phytopathogenic mould of Balady Orange Fruits

Yeasts are some of the most important postharvest biocontrol agents (BCAs). Postharvest oranges frequently deteriorate due to green and blue moulds, leading to significant economic losses. The purposes of the present study were to isolate blue and green moulds from infected orange fruits, to assess the ability of killer yeasts isolated from healthy orange fruits and leaves from orange orchards to control blue and green moulds and to evaluate the additive effect of BCAs in combination with 2% sodium bicarbonate (SBC), 2%, sodium benzoate (SB), 2% calcium chloride, 0.2% salicylic acid (SA) or 0.5% chitosan. Among eight fungi isolated from orange fruits showing symptoms of green and blue mulds infection, two were identified as P. digitatum and P. italicum and selected for in vitro assays. Twenty eight yeast isolates were obtained from orange leaves and from the surface of fruits. All yeasts exhibited high killer activity. Twelve yeasts reduced 22.5 –70% of P. digitatum growth while seven isolates reduced 21.1- 68.5% of P. italicum growth. The most potent yeast isolates were identified as Candida pseudotropicalis, Candida salmanticensis, Candida membranifaciens and Pichia guilliermondii. Combination of the BCAs, C. pseudotropicalis, C. salmanticensis and P. guilliermondii with SBC, CaCl2 or chitosan increased their effectiveness against P. digitatum. While combination of C. pseudotropicalis, C. membranifaciens and P. guilliermondii with these natural compounds decreased their effectiveness against P. italicum. Combination of C. membranifaciens with SA increased its effectiveness against P. digitatum. Sodium benzoate has additive effect on C. pseudotropicalis against P. digitatum and C. pseudotropicalis and P. guilliermondii against P. italicum

Optimization of visible photoluminescence emission from Ni-Zn ferrite thin films

Ni-Zn ferrite films with different thicknesses were prepared by the spray method, aiming to study the relationship between the annealing effect in an oxygen rich environment and the structural, optical properties and photoluminescence emission. X-ray diffraction (XRD) analysis used with Rietveld refinement showed that all prepared samples had a single spinel phase structure. Likewise, the Fourier transform infrared (FTIR) spectra confirmed the phase formation of Ni-Zn ferrites by appearing in both of the two characteristic absorption bands which are related to the tetrahedral and octahedral sites. For annealed thin film samples of Ni-Zn ferrite, the atomic force microscope (AFM) surface morphology exhibits pinning structure on the surface in nanoscale height, whereas for un-annealed samples, there are hills and valleys cover a broad region. The different electronic transitions were estimated from the UV-visible transmission spectrum. Strong photoluminescence (PL) intensity in the visible range was observed under the excitation of UV radiation. The intensity of the PL signal was strongest at a film thickness of 750 nm then decreased for higher thicknesses. This could be interpreted by using proposed energy level structures based on the transmission spectrum of the investigated samples. The strong PL intensity introduces the samples as a direct optical detector for UV radiation

Influence Parameters on Nitriding Process of Ferromanganese Alloy

A 24 factorial design technique was used to investigate the magnitude effect of temperature, time, carbon percent, and pressure of the nitriding process of gas solid reaction of ferromanganese. The design was based on experiments results obtained from nitriding of two grades of ferromanganese alloys containing 0.23% C and 7.1% C at temperatures 700°C and 950°C, during time of 2 hours and 6 hours and with nitrogen pressure of 1 and 8 bar. The required calculations were carried out by Matlab. It was found that the highest positive effect was temperature while the carbon content has the highest negative effect. Nitrogen pressure has more positive effect than time. The interaction combination between two parameters or more of temperature, nitrogen pressure, and time has positive influence with different extent. The interaction combination between carbon and one or more of parameters of time, temperature, or nitrogen pressure has negative effect on nitriding process. The driven models were found to be in good agreement with the experiments and published work of nitriding process of ferromanganese containing different carbon contents (0.23–7.1%) in temperature range 700°C–950°C, with nitrogen pressure up to 8 bar, and during time of 2–6 hours

Impact of high fat low carbohydrate enteral feeding on weaning from mechanical ventilation

Introduction: Diet can affect the outcome of mechanical ventilation in patients with chronic respiratory failure. Aim of the work: To compare the effect of a high fat, low carbohydrate enteral feeding to a standard iso-caloric enteral feeding on arterial carbon dioxide tension and ventilation time in patients with type II respiratory failure secondary to pulmonary disease requiring mechanical ventilation. Subjects and methods: One hundred patients with type II respiratory failure secondary to pulmonary disease requiring mechanical ventilation who could be enterally fed in the respiratory intensive care unit of Ain Shams University Hospitals were enrolled in this study. They were divided randomly into: Group A: included fifty patients who received standard iso-caloric feeding with carbohydrates (53.3%), fats (30%) and proteins (16.7%). Group B: included fifty patients who received iso-caloric high fat low carbohydrate feeding with carbohydrates (28.1%), fats (55.2%) and proteins (16.7%) also through the Ryle tube. Results: Group B had 16% decrease in arterial carbon dioxide tension, 8% decrease in the minute volume at weaning, and spent on average 62 h less on mechanical ventilation. Conclusion: A nutritional regimen with a high fat content may reduce ventilatory requirements and therefore reduce the duration of mechanical ventilation

The Effect of Opto-Electronic Transition Type on the Electric Resistivity of Cr-Doped Co₃O₄ Thin Films

Cr-doped Co3O4 thin films were prepared by spray pyrolysis on soda-lima glass. The structure and morphology of the prepared samples were characterized by grazing incidence X-ray diffraction (GIXRD), Fourier-transform infrared spectroscopy (FTIR) and Scanning electron Microscopy (SEM). The results indicated the formation of a single cubic spinel phase with a crystallite size of about 6 nm. Different electronic transitions and estimations of the band gap structure were determined from the optical absorption spectra. The dependence of electrical resistivity on Cr content was investigated. It was found that the resistivity increased by increasing the Cr content. In addition, the effect of photon excitation on the electrical properties showed that the electrical resistivity decreased under visible illumination (λvis. = 532 nm) and increased under infrared illumination (λIR = 780 nm). The relative change in resistivity (sensitivity) under both light illuminations was enhanced by increasing the Cr content. Therefore, this work introduces a new application for Co3O4 material as a light detector

Camel molar tooth enamel response to gamma rays using EPR spectroscopy.

Tooth enamel samples from molar teeth of camel were prepared using a combined procedure of mechanical and chemical tooth treatment. Based on electron paramagnetic resonance (EPR) spectroscopy, the dose response of tooth enamel samples was examined and compared to that of human enamel. The EPR dose response of the tooth enamel samples was obtained through irradiation to gamma doses from 1 Gy up to 100 kGy. It was found that the radiation-induced EPR signal increased linearly with gamma dose for all studied tooth enamel samples, up to about 15 kGy. At higher doses, the dose response curve leveled off. The results revealed that the location of the native signal of camel tooth enamel was similar to that of enamel from human molars at 2.00644, but different from that of enamel from cows and goats. In addition, the peak-to-peak width (Delta H (pp)) for human and camel molar teeth was similar. It was also found that the response of camel enamel to gamma radiation was 36% lower than that of human enamel. In conclusion, the results indicate the suitability of camel teeth for retrospective gamma dosimetry