Prevalence of Antibodies to Hepatitis B Virus Antigens and Occult Hepatitis B Virus Infection in Blood Donors

Background: Occult hepatitis B virus (HBV) is the presence of HBV DNA in liver tissue and/or in serum in the absence of detectable hepatitis B surface antigen (HBsAg). It is a world-wide entity that is considered as a potential risk for transmission of HBV infection. Aim: This study was aimed to determine the rate of occult HBV infection among unpaid blood donors in Diyala province-Iraq. Subjects and methods: This study was conducted for the period from 1st. May 2011 to 1st. April 2012. A total of 186 unpaid blood donors were chosen by simple random selection from those attending the Central Blood Bank in the Public Health Laboratory in Diyala province. 171 (91.9%) were male and 15 (8.1%) were female. The age range was 19-60 years. Sera of blood donors were subjected for HBsAg screening test, anti-HBs antibody, anti-HBc IgM antibody by enzyme linked immunosorbant assay (ELISA), as well as detection of HBV DNA by conventional polymerase chain reaction (PCR) technique. Data were statistically analyzed. Results: The positivity rate of HBsAg, anti-HBc IgM and HBV DNA were 4.3%, 3.2% and 8.1%. Among the HBsAg negative blood donors, the HBc IgM positivity rate were 3.4% and the HBV DNA was detected in 3.9% (occult HBV).  Conclusion: The relatively high rate of occult hepatitis B viral infection among blood donors may be responsible, at least in part, for the perpetuation of the infection in the community

Fabrication of gum arabic-graphene (GGA) modified polyphenylsulfone (PPSU) mixed matrix membranes: A systematic evaluation study for ultrafiltration (UF) applications

In the current work, a Gum, Arabic-modified Graphene (GGA), has been synthesized via a facile green method and employed for the first time as an additive for enhancement of the PPSU ultrafiltration membrane properties. A series of PPSU membranes containing very low (0–0.25) wt.% GGA were prepared, and their chemical structure and morphology were comprehensively investigated through atomic force microscopy (AFM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Besides, thermogravimetric analysis (TGA) was harnessed to measure thermal characteristics, while surface hydrophilicity was determined by the contact angle. The PPSU-GGA membrane performance was assessed through volumetric flux, solute flux, and retention of sodium alginate solution as an organic polysaccharide model. Results demonstrated that GGA structure had been successfully synthesized as confirmed XRD patterns. Besides, all membranes prepared using low GGA content could impart enhanced hydrophilic nature and permeation characteristics compared to pristine PPSU membranes. Moreover, greater thermal stability, surface roughness, and a noticeable decline in the mean pore size of the membrane were obtained

Green Synthesis of Fe3O4 Nanoparticles and Its Applications in Wastewater Treatment

In this paper, the extract of Citrus aurantium (CA) was used as a green approach for the preparation of Fe3O4 nanoparticles. The green Fe3O4 (Fe3O4/CA) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier-transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and vibrating sample magnetometry (VSM). The synthesized Fe3O4/CA was used to remove methylene blue (MB) dye from an aqueous solution. A four-factor central composite design (CCD), combined with response surface modeling (RSM), was used to maximize the MB dye removal. The four independent variables, which were initial dye concentration (10–50 mg/L), solution pH (3–9), adsorbent dose (ranging from 200–1000 mg/L), and contact time (30–90 min), were used as inputs to the model of the perecentage dye removal. The results yielded by an analysis of variance (ANOVA) confirmed the high significance of the regression model. The predicted values of the MB dye removal were in agreement with the corresponding experimental values. Optimized conditions for the maximum MB dye removal (93.14%) by Fe3O4/CA were the initial dye concentration (10.02 mg/L), pH (8.98), adsorbent mass (997.99 mg/L), and contact time (43.71 min). The validity of the quadratic model was examined, and good agreement was found between the experimental and predicted values. Our findings demonstrated that green Fe3O4NPs is a good adsorbent for MB removal

Green Synthesis of Fe₃O₄ Nanoparticles and Its Applications in Wastewater Treatment

In this paper, the extract of Citrus aurantium (CA) was used as a green approach for the preparation of Fe3O4 nanoparticles. The green Fe3O4 (Fe3O4/CA) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier-transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and vibrating sample magnetometry (VSM). The synthesized Fe3O4/CA was used to remove methylene blue (MB) dye from an aqueous solution. A four-factor central composite design (CCD), combined with response surface modeling (RSM), was used to maximize the MB dye removal. The four independent variables, which were initial dye concentration (10–50 mg/L), solution pH (3–9), adsorbent dose (ranging from 200–1000 mg/L), and contact time (30–90 min), were used as inputs to the model of the perecentage dye removal. The results yielded by an analysis of variance (ANOVA) confirmed the high significance of the regression model. The predicted values of the MB dye removal were in agreement with the corresponding experimental values. Optimized conditions for the maximum MB dye removal (93.14%) by Fe3O4/CA were the initial dye concentration (10.02 mg/L), pH (8.98), adsorbent mass (997.99 mg/L), and contact time (43.71 min). The validity of the quadratic model was examined, and good agreement was found between the experimental and predicted values. Our findings demonstrated that green Fe3O4NPs is a good adsorbent for MB removal

Experimental and kinetic studies of the advantages of coke accumulation over Beta and Mordenite catalysts according to the pore mouth catalysis hypothesis

Coke formation inside heterogeneous reactors is an important industrial problem that leads to reduced catalyst efficiency. However, this study aims to prove the benefits of coke build-up in improving catalyst performance. The formation and decomposition of coke on six different zeolite structures was studied. The dissociation kinetic model of the spent catalysts during the toluene alkylation with 1-heptene inside a stainless-steel autoclave reactor at different temperatures was carried out. Various techniques (XRD, XRF, TPO, CHNS and TGA-DTG) were used. It was found that the conversion and selectivity of the desired product were higher on the parent H-mordenite and the dealuminated H-beta catalysts with conversions of 85.3% and 84.67%, respectively, at a 360 min reaction time. This was attributed to the reduction of the ratio of hard:soft coke. It is confirmed that the decomposition activation energies of hard coke, 140.1–202.6 kJ/mol, are much higher energies than those of soft coke, 89.9–118.7 kJ/mol. It is also noted that the hypothesis of pore mouth catalysis is dominated by non-polyaromatic coke on the surface of the H-beta catalysts, while the hypothesis is dominated by polyaromatic coke on the surface of the H-mordenite catalysts