Production of Prednisolone by Pseudomonas oleovorans Cells Incorporated Into PVP/PEO Radiation Crosslinked Hydrogels

In order to rise the yield of prednisolone from hydrocortisone, the Pseudomonas oleovorans cells were entrapped into radiation crosslinked poly (vinyl pyrrolidone)/poly(ethylene oxide) (PVP/PEO) hydrogel of different gel contents. The factors affecting the gel content and swelling behavior of the polymeric gel, such as polymer composition, polymer blend concentration, and irradiation doses, were investigated. The formation of gels having a good strength with the ability to retain a desirable amount of water in their three-dimensional network can be achieved by using PVP/PEO copolymer of composition (90 : 10) and concentration of 15% prepared at 20 kGy irradiation dose. At these conditions the prepared hydrogel is considered the most favorable one that gave the highest hydrocortisone bioconversion and prednisolone yield, 81% and 62.8%, respectively. The improvement of prednisolone yield was also achieved by increasing substrate concentration. Maximum hydrocortisone bioconversion (86.44) was obtained at 18 hours by using substrate concentration of 30 mg. Reusability of immobilized Pseudomonas oleovorans entrapped into PVP/PEO copolymer hydrogel was studied. The results indicated that the transformation capacity of hydrocortisone to prednisolone highly increased by the repeated use of copolymer for 4 times. This was accompanied by an increase in prednisolone yield to 89% and the bioconversion of hydrocortisone was 98.8%

Preparation of Low Molecular Weight Natural Polymers by gamma-Radiation and Their Growth Promoting Effect on Zea Maize Plants

Preparation of oligosaccharides from chitosan and Na-alginate were done using ?-rays and H2O2 as oxidizing agent. Structural and molecular weight changes of such oligosaccharides were determined by GPC, FT-IR and UV-Vis. spectroscopy. FT-IR and UV-Vis. studies revealed that during radiation degradation process, the main polysaccharide chain structure was almost remained. The effects of spraying 100 ppm of oligochitosan or oligoalginate or both of them with different ratios on the growth of zea maize plants showed an enhancement of plant growth performance and the productivity at the same time suggesting their possible use in agriculture purposes as growth promoters for plants

Tissue p53-induced glycolysis and apoptosis regulator (TIGAR) is associated with oxidative stress in benign and malignant colorectal lesions

Background: Colorectal cancer (CRC) is the fourth leading cause of cancer-mortality worldwide. Tissue p53-induced glycolysis and apoptosis regulator gene (TIGAR) has an important role in cellular glycolysis and acts as an oncogene.Objectives: We aimed to investigate the diagnostic utility of TIGAR in both CRC and benign bowel deceases.Methods: One-hundred-eighty tissue samples were recruited and classified into 3 groups: group (1) 60 CRC samples from the tumor mass of colorectal cancer patients, group (2), 60 non-neoplastic colorectal tissue samples and group (3), 60 benign bowel lesions samples (ulcerative-colitis, Chron’s disease, adenoma, and familial adenomatous polyposis). The expressions of tissue mRNA and protein levels of TIGAR were determined. Levels of malondialdehyde and reduced glutathione were also measured.Results: Our results showed upregulated expressions of TIGAR gene and protein levels in CRC tissues and benign colonic lesions compared to non-tumor tissues (p < 0.0001). Their levels were higher in inflammatory bowel diseases compared to non-inflammatory benign lesions. There were significant relations among TIGAR expression, protein levels, TNM staging, and the presence of metastasis (p<0.0001). ROC curve analysis showed that TIGAR mRNA expression and its protein can discriminate between CRC and benign lesions and between benign bowel disease and controls.Conclusions: To the best of our knowledge this is the first study to assess the level of TIGAR in different benign bowel diseases. TIGAR might be involved in the pathogenesis of benign and malignant bowel diseases and could be a potential biomarker for diagnosis

Inhibitive action of gramine towards corrosion of mild steel in deaerated 1.0 M hydrochloric acid solutions

The effect of addition of gramine on mild steel dissolution in deaerated 1.0 M hydrochloric acid was studied through potentiodynamic polarisation curves, electrochemical impedance spectroscopy and gravimetric measurements in the temperature range from 25 °C to 55 °C. Gramine was found to shift the corrosion potentials towards less noble values and decrease both dissolution of mild steel and hydrogen evolution reaction. Gramine did not affect the corrosion reaction mechanism (blocking effect). Results obtained from the several measurement techniques were in good agreement and revealed good inhibition efficiencies in the concentration range (0.75 mM ÷ 7.5 mM) particularly at higher concentrations

Antimicrobial ZnO Nanoparticle–Doped Polyvinyl Alcohol/Pluronic Blends as Active Food Packaging Films

Today, plastic waste has been highlighted as one of the greatest threats to the environment. These environmental concerns and the increased necessity for safe food packaging have inspired scientists to focus on the development of active biodegradable materials. Herein, a novel poly(vinyl alcohol)/pluronic/ZnO nanocomposite film (PVA/PLUR/ZnO) is introduced as an active packaging material with enhanced antimicrobial activity. Gamma irradiation is used as a “green” route to prepare ZnO nanoparticles via a polymer pyrolysis method. The as‐prepared ecofriendly ZnO nanoparticles are characterized and incorporated into the PVA/PLUR matrix in different concentrations. Transmission electron microscopy and dynamic light scattering measurements prove that ZnO nanoparticles have a mean particle size of 30 nm with a spherical‐like morphology. Morphological and structural characterization confirm the successful incorporation of ZnO into the PVA/PLUR matrix, which in turn enhances the thermal and barrier properties of PVA/PLUR/ZnO nanocomposite films. On the other hand, the opacity of blends is increased. The PVA/PLUR/ZnO composites exhibit broad‐spectrum antimicrobial activity against Gram‐positive, Gram‐negative bacterial pathogens, and fungi, and the activity increases with increasing concentrations of ZnO nanoparticles. These results introduce PVA/PLUR/ZnO films as effective antimicrobial materials for active food‐packaging applications

Influence of gamma rays on the physico-chemical, release and antibacterial characteristics of low-density polyethylene composite films incorporating an essential oil for application in food-packaging

We investigated the effect of gamma irradiation on the properties of low-density polyethylene composite films incorporated with the antimicrobial terpene 4-allylanisole (ALY), and the volatile release of ALY. For comparison, wood flour and molecular sieves were used as solid carriers for ALY at loading ratios of 20 and 30 wt.%. Infrared spectroscopy indicated that a proportion of ALY underwent structural change during melt-compounding and irradiation at high doses (> 10 kGy). Thermal and mechanical properties of composites prepared did not alter remarkably after irradiation. The release study of ALY showed that using wood flour and irradiation reduced the volatilization of ALY from the polymer matrix; however, the effect exerted by irradiation treatment was less noticeable than that of the carrier type. The antibacterial activity study demonstrated that irradiation only exerted a pronounced negative effect on samples that contained 30 wt.% of ALY/wood flour when irradiated at 30 and 50 kGy. © 2018 Elsevier LtdMinistry of Education, Youth and Sports of the Czech Republic [LO1504, CZ.1.05/2.1.00/19.0409