Browsing by Author "Aslan, Y."

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Improved Catalytic Activity of Aspergillus Oryzae Β-Galactosidase by Covalent Immobilization on Eupergit Cm
(Pakistan Agricultural Scientists Forum, 2018) Aslan, Y.; Taher, A. Y.; Cavidoglu, I
In this study, Aspergillus oryzae beta-Galactosidase (AOG) was immobilized onto Eupergit CM. By optimizing the immobilization conditions such as pH and molarity of immobilization buffer, enzyme/support ratio and duration of immobilization, 100.00% immobilization yield and 129.82% activity yield was achieved. The optimum temperature (55 degrees C) of free enzyme was not changed while optimum pH of free enzyme was shifted from 4.5 to 5.5 after immobilization. Kinetic constants for free and immobilized enzyme were also determined by using the Lineweaver-Burk plot. The K-m values of the free and immobilized enzymes were determined to be 307.7 and 234.2 g / L respectively, while the V-max values were determined to be 0.366 g D-Glucose / L.min and 0.415 g D-Glucose / L.min respectively. The operational and storage stabilities of immobilized enzyme were also studied. The activity of immobilized enzyme decreased to 99.3% after repeated twenty usage while decreased to 98.3% after fifteen days of storage. Further, the immobilized enzyme was used for the hydrolyzing the cow's milk lactose. By using the immobilized enzyme, the milk lactose was completely hydrolyzed in four hours. Consequently, immobilized AOG can be used in the industrial production of lactose-free cow's milk.
Respiratory Syncytial Virus Epidemiology in Turkey
(2005) Kanra, G.; Tezcan, S.; Yilmaz, G.; Acunas, B.; Aslan, Ş.; Aslan, Y.; Yurdakök, M.
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children worldwide. This study was conducted to determine the prevalence of RSV among high-risk children admitted with respiratory symptoms in a developing country. This is a multicenter study conducted among children less than 24 months of age and admitted to the hospital with respiratory symptoms. The inclusion criteria included: lower respiratory tract symptoms on admission, gestational age less than 35 weeks, and admission age less than six months, or children less than 24 months of age with a diagnosis of bronchopulmonary dysplasia requiring medical treatment or intervention during the last six months or with an uncorrected congenital heart disease (other than patent ductus arteriosus). Nasopharyngeal samples were obtained with one of the three standard methods: nasopharyngeal aspirate, nasopharyngeal wash or nasopharyngeal swab. RSV antigen was determined by enzyme immunoassay using Abbott TESTPACK RSV (No. 8100/2027-16). Statistical analysis was performed using Student's t-test and chi-square test. In this study, 332 children (135 females, 40.7%; 197 males, 59.3%) were included, and the nasopharyngeal specimens of 98 (29.5%) children were determined to be RSV-positive. There were no differences in sex, age of gestation, age of admission, family education, number of siblings and smoking at home for RSV-positive and -negative cases. Furthermore, underlying disease and duration of hospital and intensive care unit stay were similar among groups. Only otitis media was more common among RSV-positive cases. No fatality at hospital was recorded. Frozen samples revealed more negative results. Most cases presented during winter and the number of RSV-positive cases was higher in cold and economically poor areas. Premature children and children with underlying medical con dition acquire RSV irrespective of other sociodemographic risk factors, and most of them are hospitalized. Thus, an RSV vaccine seems the most effective mode of protection to decrease morbidity and mortality.