Preparation and characterization of chitosan/polyacrylic acid/copper nanocomposites and their impact on onion production.

Chitosan nanoparticles (CS-NPs) and chitosan/polyacrylic acid hydrogel nanoparticles (CS/PAA-HNPs) were obtained by ionic gelation with tripolyphosphate anions and copolymerization of CS with acrylic acid (AA), respectively. The prepared NPs were loaded by different concentrations of copper (1, 2 and 3% with respect to CS) to obtain chitosan/copper nanocomposites (CS/Cu-NCs) and chitosan/polyacrylic acid/copper hydrogel nanocomposites (CS/PAA/Cu-HNCs). The prepared NPs and their NCs were characterized by different techniques. The swelling properties and copper release from CS/Cu-NCs and CS/PAA/Cu-HNCs were evaluated. The antibacterial activity of the prepared samples against bacteria (e.g., Staphylococcus aureus and Pseudomonas aeruginosa), fungi, and yeast were investigated. The results displayed that the copper release, as well as the swelling percentage of CS/PAA/Cu-HNCs, were higher than that of CS/Cu-NCs. Furthermore, the impact of using CuSO4, CS/Cu-NCs, and CS/PAA/Cu-HNCs as a different source of copper on chlorophyll content, vegetative growth, minerals content, and the yield of onion plants during two seasons 2016 and 2017 were studied. It was found that the yield, plant growth, and nutrient content of onion bulbs were improved using CS/PAA-HNPs, which was loaded with 75 ppm copper, as foliar spray for onion plants.

Biodegradable grafting cellulose/clay composites for metal ions removal.

Biodegradable bi-functional cellulose derivatives were synthesized to remove widespread underground water cations such as; Ca2+, Mg2+, Fe2+, Pb2+, and Cu2+. Firstly, graft copolymerization of cellulose with binary monomers such as acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) with acrylamide (Am) were achieved using potassium persulfate as initiator. Then, cellulose/clay composites were prepared by graft copolymerization of cellulose using different montmorillonite concentrations such as 3, 6 and 9% weight/cellulose weight. The obtained Biodegradable grafted cellulose and their composites were used as adsorbents for the removal of Ca, Mg, Fe, Pb, and Cu ions individually from aqueous solutions. A possible reaction mechanism was deduced and the products were characterized by Fourier transfer infrared (FT-IR), scanning electron microscopy (SEM) and thermal degradation by thermogravimetric analysis (TGA). The results obtained from this study revealed that as the content of clay increases, the uptake of cations increasing and the removal order of the composites were Pb2+ > Mg2+ > Fe2+ > Cu2+ > Ca2+. The biodegradability of grafted cellulose was increased by the addition of clay.

Morphological, electrical & antibacterial properties of trilayered Cs/PAA/PPy bionanocomposites hydrogel based on Fe3O4-NPs.

Bionanocomposites hydrogel based on conducting polymers were successfully fabricated from chitosan/polyacrylic acid/polypyrrole (CS/PAA/PPy) as well as the magnetite nanoparticle (Fe3O4-NPs) was prepared via co-precipitation method. In addition, different ratios of Fe3O4-NPs were added to the prepared bionanocomposites to enhance the antimicrobial and the electrical conductivity of the prepared conductive hydrogel. Furthermore, the morphology, the swelling percent, antimicrobial activity and the dielectric properties of the prepared conducting bionanocomposites hydrogel were investigated. The antibacterial activities of the experienced microbes were improved with the increasing the loading of Fe3O4-NPs in conducting Bio-nanocomposites hydrogel. Moreover, the DC-conductivity was examined and our resulted indicated that the DC-conductivity was enhanced by increasing the loadings of Fe3O4-NPs compared to that of the pure CS/PAA as well as CS/PAA/PPy.

Predictors of Mortality in Living Donor Liver Transplantation.

BACKGROUND: Egypt has the highest prevalence of the world hepatitis C virus (HCV) load. Hence, the problem of end-stage liver disease (ESLD) is considered a huge burden on the community. Living donor liver transplantation (LDLT) is the only source of donation in Egypt till now. Survival rates had shown significant improvement in the past decades. This study provides analysis of the mortality rates and possible predictors of mortality following LDLT. It also aids in developing a practical and easy-to-apply risk index for prediction of early mortality. PATIENTS AND METHODS: This study is a retrospective study that was designed to analyze data from 128 adult patients with ESLD who underwent LDLT in the Liver Transplantation Unit at Faculty of Medicine, Cairo University. Early and late mortality were identified. All potential risk factors were tested using univariate regression for association with early and late mortality. Significant variables were then entered into a multivariable logistic regression model for identifying the predictors for mortality. RESULTS: Sepsis was the most common cause of early mortality. Early mortality and 1-year mortality were 29 (23%) and 23 (18%), respectively. Model for End-Stage Liver Disease (MELD) score, intraoperative packed red blood corpuscles (RBCs), and duration of intensive care unit (ICU) stay were found to be independently associated with early mortality. CONCLUSION: A MELD score >20, intraoperative transfusion >8 units of packed RBCs, and ICU stay >9 days are three independent predictors of early mortality. Their incorporation into a combined Risk Index can be used to improve outcomes of LDLT.

Biological studies and electrical conductivity of paper sheet based on PANI/PS/Ag-NPs nanocomposite.

Polyaniline (PANI) with/without polystyrene (PS), was successfully manufactured in the occurrence of dispersed pulp fibers via the oxidative polymerization reaction of aniline monomer to produce conductive paper sheets containing PANI, PANI/PS composites. Additionally, sliver nitrate (Ag-NO3) was added by varied loadings to the oxidative polymerization of aniline monomer to provide sliver nanoparticles (Ag-NPs) emptied into the prepared paper sheets. The prepared paper sheets were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR), the mechanical properties of the prepared paper sheets were evaluated. Moreover, the electrical conductivity and biological studies such as cellulases assay, Microorganism & culture condition and detection of the released of Ag-NPs were evaluated. Furthermore, the prepared paper sheets were displayed good antibacterial properties contrary to gram positive and gram negative bacteria. Consequently, the prepared paper sheet may be used as novel materials for packaging applications.

Rapid test methods for minor components analysis of hydraulic cement. Spectrophotometric determination of manganese oxide content of Portland cement and cement raw meal.

A rapid, sensitive and highly selective spectrophotometric method for the determination of manganese oxide content of Portland cement and cement raw meal is developed. The method is based on the reaction of manganese(II) with 1,2,4 trihydroxyanthraquinone (purpurin, PURP) in 50% v/v ethanol-water solution at pH 8.5. The solution equilibria of manganese chelates are demonstrated and characterized for delineating optimal conditions of the complexation reaction and analytical aspect of the Mn-PURP system. The analysis of cement materials of variable manganese content is feasible over the concentration range 1.67-8.13 microg ml(-1) Mn, the limit of detection (at the 95% confidence level) of the method is 68 ng ml(-1) for manganese. Under optimum conditions, the use of first derivative spectrophotometry has the advantage of high sensitivity than normal spectrophotometric method and allows the determination of 0.5 microg ml(-1) of manganese.