Celal Bayar University

About: Celal Bayar University is a education organization based out in Magnesia ad Sipylum, Turkey. It is known for research contribution in the topics: Population & Heat transfer. The organization has 2960 authors who have published 6024 publications receiving 100646 citations.

New perturbation-iteration solutions for Bratu-type equations

Abstract: Perturbation-iteration theory is systematically generated for both linear and nonlinear second-order differential equations and applied to Bratu-type equations. Different perturbation-iteration algorithms depending upon the number of Taylor expansion terms are proposed. Using the iteration formulas derived using different perturbation-iteration algorithms, new solutions of Bratu-type equations are obtained. Solutions constructed using different perturbation-iteration algorithms are contrasted with each other as well as with numerical solutions. It is found that algorithms with more Taylor series expansion terms yield more accurate results.

Optimization of counter flow Ranque-Hilsch vortex tube performance using Taguchi method

Abstract: This study discusses the application of Taguchi method in assessing maximum temperature gradient for the Ranque–Hilsch counter flow vortex tube performance. The experiments were planned based on Taguchi's L27 orthogonal array with each trial performed under different conditions of inlet pressure, nozzle number and fluid type. Signal-to-noise ratio (S/N) analysis, analysis of variance (ANOVA) and regression analysis were carried out in order to determine the effects of process parameters and optimal factor settings. Finally, confirmation tests verified that Taguchi method achieved optimization of counter flow Ranque–Hilsch vortex tube performance with sufficient accuracy.

Primary Tumors of the Spine

Abstract: Spinal tumors consist of a large spectrum of various histologic entities. Multiple spinal lesions frequently represent known metastatic disease or lymphoproliferative disease. In solitary lesions primary neoplasms of the spine should be considered. Primary spinal tumors may arise from the spinal cord, the surrounding leptomeninges, or the extradural soft tissues and bony structures. A wide variety of benign neoplasms can involve the spine including enostosis, osteoid osteoma, osteoblastoma, aneurysmal bone cyst, giant cell tumor, and osteochondroma. Common malignant primary neoplasms are chordoma, chondrosarcoma, Ewing sarcoma or primitive neuroectodermal tumor, and osteosarcoma. Although plain radiographs may be useful to characterize some spinal lesions, magnetic resonance imaging is indispensable to determine the extension and the relationship with the spinal canal and nerve roots, and thus determine the plan of management. In this article we review the characteristic imaging features of extradural spinal lesions.

Nesfatin-1 and ghrelin levels in serum and saliva of epileptic patients: hormonal changes can have a major effect on seizure disorders.

Abstract: Nesfatin-1 and ghrelin are the two recently discovered peptide hormones involved in the control of appetite. Besides its main appetite-control function, ghrelin also has anticonvulsant effects, while nesfatin-1 causes depolarization in the paraventricular nucleus (PVN). The aims of this study, therefore, were to investigate: (i) whether there are differences in the concentrations of nesfatin-1 and ghrelin in saliva and serum samples between eplilepsy patients and normal controls and (ii) whether salivary glands produce nesfatin-1. The study included a total of 73 subjects: 8 patients who were newly diagnosed with primary generalized seizures and had recently started antiepileptic drug therapy; 21 who had primary generalized seizures and were continuing with established antiepileptic drug therapy; 24 who had partial seizures (simple: n = 12 or complex: n = 12) and were continuing with established antiepileptic drug therapy; and 20 controls. Salivary gland tissue samples were analyzed for nesfatin-1 expression by immunochemistry and ELISA. Saliva and serum ghrelin levels were measured by ELISA and RIA, and nesfatin-1 levels by ELISA. Nesfatin-1 immunoreactivity was detected in the striated and interlobular parts of the salivary glands and the ducts. The nesfatin-1 level in the brain was around 12 times higher than in the salivary gland. Before antiepileptic treatment, both saliva and serum nesfatin-1 levels were around 160-fold higher in patients who are newly diagnosed with primary generalized epilepsy (PGE) than in controls; these levels decreased with treatment but remained about 10 times higher than the control values. Saliva and serum nesfatin-1 levels from patients with PGE and partial epilepsies who were continuing antiepileptic drugs were also 10-fold higher than control values. Serum and saliva ghrelin levels were significantly (twofold) lower in epileptic patients before treatment than in controls; they recovered somewhat with treatment but remained below the control values. These results suggest that the low ghrelin and especially the dramatically elevated nesfatin-1 levels might contribute to the pathophyisology of epilepsy. Therefore, serum and saliva ghrelin and especially the remarkably increased nesfatin-1 might be candidate biomarkers for the diagnosis of epilepsy and for monitoring the response to anti-epileptic treatment.