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Öğe Analysis of charge variation in fractional order LC electrical circuit(Soc Mexicana Fisica, 2016) Calik, A. E.; Sirin, H.; Ertik, H.; Sen, M.In this paper, the charge variation in time has been investigated in electrical LC circuit within the framework of fractional calculus. The second order differential equation related to the LC circuit has been re-solved by using Caputo fractional derivative. The solution of this new equation has been obtained in terms of Mittag-Leffier function which behaves in between power law and exponential law forms. The order of time-fractional derivative characterizes the time fractality effects in the system, and is considered in the interval 1 < alpha < 2. The obtained results have been compared with the other studies in the literature. It has been concluded that the Mittag-Leffier function and the order of time-fractional derivative have a special importance to take into account the non-local behaviour of the physical process in time.Öğe Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates(Blackwell Publishing, 2006) Sagduyu, A.; Sirin, H.; Mulayim, S.; Bademkiran, F.; Yunten, N.; Kitis, O.; Calli, C.; Dalbasti, T.; Kumral, E.Background - Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT. Methods - Forty-six patients with venous stroke proved on MRI included in our Registry, corresponding to 0.1% of 4650 patients with stroke, were studied. Magnetic resonance angiography (MRA) was performed in all patients, and 18 of them had follow-up MRA. Outcome was evaluated by using the Glasgow Outcome Scale at the time of discharge and during follow-up. Results - Thirty-two patients presented cortical venous stroke; 21 of them had involvement of the dorsomedial venous system, six had a defect in the posteroinferior venous group, and five had a defect in the anteroinferior venous group. Thirteen patients presented simultaneous involvement of the superficial and deep venous system; seven with a defect in the parietal and internal cerebral veins (three with involvement of vein of Gallen), four with a defect in the temporooccipital (vein of Labbe) and basal vein of Rosenthal, two with a deficit in the anterior frontotemporal and uncal-pterygoid venous system. One patient had deep venous thrombosis primarily localized to the thalami bilaterally and the basal ganglia on the right because of occlusion of the thalamostriate veins. The main presenting symptoms of CDVT were headache, focal neurologic signs, partial complex or secondary generalized seizures, and consciousness disturbances in those with deep venous thrombosis, presented alone or in combination at onset. CDVT was more than twofold more frequent in women than in men. Pregnancy, puerperium, oral contraceptive use, and infections were the most common predisposing factors. Conclusions - Computerized tomography, conventional MRI and diffusion-weighted imaging showing ischemic and/or hemorrhagic lesion that does not follow the boundary of classical arterial boundaries without signs of sinus thrombosis, and partial or generalized seizures followed by focal neurologic signs may predict CDVT. The outcome of patients with cortical venous stroke was good, but not in those with cortical plus deep venous infarction.Öğe CEREBRAL VENOUS THROMBOSIS AND TURNER SYNDROME: A RARE REPORTED ASSOCIATION(Medecine Et Hygiene, 2015) Guler, A.; Alpaydin, S.; Bademkiran, F.; Sirin, H.; Celebisoy, N.Cerebral venous thrombosis and Turner Syndrome: a rare reported association: Turner Syndrome is the only known viable chromosomal monosomy, characterised by the complete or partial absence of an X chromosome. It's the most common chromosomal abnormality in females. Apart from the well known dysmorphic features of the syndrome, it has been associated with a number of vascular pathologies; mainly involving the cardiovascular, renovascular, peripheral vascular and cerebrovascular system. It seems striking that thromboembolism is not considered as a feature of the syndrome. Most of the thromboembolism cases are related to the arterial vascular system; except for some rare reported portal venous thrombosis cases, peripheral venous thrombosis cases and to the best of our knowledge a single case of cerebral venous thrombosis with Dandy Walker malformation and polymicrogyria. We herein report a cerebral venous thrombosis case with Turner Syndrome. With no other found underlying etiology, we want to highlight that Turner Syndrome, itself, may have a relationship not only with the cerebral arterial vascular system pathologies but also with the cerebral venous thrombosis.Öğe A comparative ID migraine (TM) screener study in ophthalmology, ENT and neurology out-patient clinics(Sage Publications Ltd, 2009) Ertas, M.; Baykan, B.; Tuncel, D.; Goekce, M.; Goekcay, F.; Sirin, H.; Deniz, O.; Oeztuerk, V.; Idiman, F.; Karli, N.; Zarifoglu, M.; Yildiz, N.; Siva, A.; Saip, S.; Goeksan, B.; Ak, F.; Aluclu, U.; Duman, T.; Melek, I. M.; Bulut, S.; Berilgen, S.Migraine is more likely to be misdiagnosed in patients with comorbid diseases. Not only primary care physicians, but also specialists might misdiagnose it due to the lack of diagnostic criteria awareness. The ID migraine test is a reliable screening instrument that may facilitate and accelerate migraine recognition. This study aimed to compare the prevalence and characteristics of migraine in a large sample of patients admitted to clinics of ophthalmology (OC), ear, nose and throat diseases (ENTC) and neurology (NC), as well as to validate the use of the ID migraine test in OC and ENTC settings. This was a multicentre (11 cites) study of out-patients admitting either to NC, ENTC or OC of the study sites during five consecutive working days within 1 week. From each of the clinics, 100 patients were planned to be recruited. All recruited patients were interviewed and those having a headache complaint received an ID migraine test and were examined for headache diagnosis by a neurologist, blinded to the ID migraine test result. A total of 2625 subjects were recruited. Only 1.3% of OC patients and 5.4% of ENTC patients have been admitted with a primary complaint of headache, whereas the percentage of NC patients suffering from headache was 37.6%. Whereas 138 patients (19.3%) in OC, 154 (17.3%) in ENTC and 347 (34%) in NC were found to be ID migraine test positive, 149 patients (20.8%) in OC, 142 (16%) in ENTC and 338 (33.1%) in NC were diagnosed with migraine. The sensitivity, specificity, and positive and negative predictive ratios of the ID migraine test were found to be similar in all clinics. An important fraction of the patients admitted to NC, as well as to OC and ENTC, for headache and/or other complaints were found out to have migraine by means of a simple screening test. This study validated the ID migraine test as a sensitive and specific tool in OC and ENTC, encouraging its use as a screening instrument.Öğe Effect of decompressive craniectomy for malignant middle cerebral artery infarction especially in elderly patients: a Single center experience for 113 patients(Wiley, 2015) Guler, A.; Ciftci, S.; Sirin, H.; Celebisoy, N.; Kumral, E.; Turhan, T.; Ozgiray, E.Öğe Effect of decompressive craniectomy for malignant middle cerebral artery infarction especially in elderly patients: a Single center experience for 113 patients(Wiley, 2015) Guler, A.; Ciftci, S.; Sirin, H.; Celebisoy, N.; Kumral, E.; Turhan, T.; Ozgiray, E.Öğe Effect of decompressive craniectomy for malignant middle cerebral artery infarction especially in elderly patients: a Single center experience for 113 patients(Wiley, 2015) Guler, A.; Ciftci, S.; Sirin, H.; Celebisoy, N.; Kumral, E.; Turhan, T.; Ozgiray, E.Öğe Endovascular stenting for treatment of carotid artery stenosis: A series of 40 patients(Wiley-Blackwell, 2014) Ciftci, S.; Guler, A.; Sirin, H.; Gokcay, F.; Kumral, E.; Cinar, C.; Oran, I.Öğe Evaluation of viral etiology in central nervous system infections for seven years(Elsevier Science Bv, 2016) Zeytinoglu, A.; Erensoy, S.; Sertoz, R.; Altuglu, I.; Cicek, C.; Kayin, M.; Sirin, H.; Taner, S.Öğe Experimental and fractional analysis of half-value thicknesses of polyethylene absorber(Soc Mexicana Fisica, 2020) Calik, A. E.; Sirin, H.; Sen, M.In this study, half-value thicknesses and mass attenuation coefficients of polyethylene absorber have been measured experimentally using the beta sources Tc-99, Pm-147, Cs-137, Tl-204, Pb-210, and Cl-36. There is an inconsistency between experimental and calculated values of half value thicknesses obtained with the help of a standard attenuation equation. in order to overcome this discrepancy, the fractional attenuation equation which was redefined and resolved using Caputo fractional derivative has been used. the theoretical results obtained according to this new equation are in agreement with experimental results around 0.3 value of the order of fractional derivative.Öğe A fractional mathematical approach to the distribution functions of quantum gases: Cosmic Microwave Background Radiation problem is revisited(Elsevier Science Bv, 2009) Ertik, H.; Demirhan, D.; Sirin, H.; Buyukkilic, F.Efforts on the fundamentals of the nonextensive thermostatistical formulations of the realistic description of the physical systems have always been underway. In this context, the quantum systems of bosons and fermions are taken into consideration as g-ons. A new formalism of the unified distribution functions has been introduced using a fractional mathematical approach. With the purpose of verification of the theory, blackbody radiation problem has been investigated by making use of the generalized fractional Planck's distribution. In this context, the observed Cosmic Microwave Background Radiation (CMBR) energy density could be obtained exactly within nonextensive thermostatistical approach for the value alpha = 0.999983 of the order of the fractional derivative and for the blackbody temperature T = 2.72818 K. (C) 2009 Elsevier B.V. All rights reserved.Öğe A fractional mathematical approach to the distribution functions of quantum gases: Cosmic Microwave Background Radiation problem is revisited(Elsevier Science Bv, 2009) Ertik, H.; Demirhan, D.; Sirin, H.; Buyukkilic, F.Efforts on the fundamentals of the nonextensive thermostatistical formulations of the realistic description of the physical systems have always been underway. In this context, the quantum systems of bosons and fermions are taken into consideration as g-ons. A new formalism of the unified distribution functions has been introduced using a fractional mathematical approach. With the purpose of verification of the theory, blackbody radiation problem has been investigated by making use of the generalized fractional Planck's distribution. In this context, the observed Cosmic Microwave Background Radiation (CMBR) energy density could be obtained exactly within nonextensive thermostatistical approach for the value alpha = 0.999983 of the order of the fractional derivative and for the blackbody temperature T = 2.72818 K. (C) 2009 Elsevier B.V. All rights reserved.Öğe Headache prevalence in primary Sjogren's syndrome(B M J Publishing Group, 2007) Gokcay, F.; Oder, G.; Celebisoy, N.; Gokcay, A.; Sirin, H.; Kabasakal, Y.Öğe The influence of fractality on the time evolution of the diffusion process(Elsevier Science Bv, 2010) Sirin, H.; Buyukkilic, F.; Ertik, H.; Demirhan, D.In the literature, the deviations from standard behaviors of the solutions of the kinetic equation and the analogous diffusion equation are put forward by investigations which are carried out in the frame of fractional mathematics and nonextensive physics On the other hand, the physical origins of the order of derivative namely a in fractional mathematics and the entropy index q in nonextensive physics are a topic of interest in scientific media. In this study, the solutions of the diffusion equation which have been obtained in the framework of fractional mathematics and nonextensive physics are revised. The diffusion equation is solved by the cumulative diminuation/growth method which has been developed by two of the present authors and physical nature of the parameters a and q are enlightened in connection with fractality of space and the memory effect It has been emphasized that the mathematical basis of deviations from standard behavior in the distribution functions could be established by fractional mathematics where as the physical mechanism could be revealed using the cumulative diminuation/growth method (C) 2010 Elsevier B.V. All rights reservedÖğe Investigation of electrical RC circuit within the framework of fractional calculus(Soc Mexicana Fisica, 2015) Ertik, H.; Calik, A. E.; Sirin, H.; Sen, M.; Oder, B.In this paper, charging and discharging processes of different capacitors in electrical RC circuit are considered theoretically and experimentally. The non-local behaviors in these processes, arising from the time fractality, are investigated via fractional calculus. In this context, the time fractional differential equation related to electrical RC circuit is proposed by making use of Caputo fractional derivative. The resulting solution exhibits a feature in between power law and exponential law forms, and is obtained in terms of Mittag-Leffler function which describes physical systems with memory. The order of fractional derivative characterizes the fractality of time and being considered in the interval 0 < alpha <= 1. The traditional conclusions are recovered for alpha = 1, where time becomes homogenous and system has Markovian nature. By using time fractional approach, the discrepancies between the experimentally measured data and the theoretical calculations have been removed.Öğe Migrainous vertigo: clinical, oculographic and posturographic findings(Sage Publications Ltd, 2008) Celebisoy, N.; Gokcay, F.; Sirin, H.; Bicak, N.Migrainous vertigo (MV) is accepted as a common cause of episodic vertigo. The peripheral or central vestibular localization of the deficit as well as the pathophysiology is unclear. This prospective study was designed to assess the clinical features of MV and to search for the localization of the vestibular pathology. Thirty-five patients with MV, 20 patients with migraine and 20 healthy volunteers were studied. Comprehensive neurotological tests were performed between attacks. None of the normal controls or the patients with migraine had ocular motor deficits or caloric test abnormalities. Three patients in the MV group showed saccadic pursuit (8.6%), in one of whom saccadic hypometria was also present. Caloric test results revealed unilateral caloric hypofunction in seven patients (20%). Static posturography results revealed increased sway velocity when the eyes were closed or the platform was distorted in patients with MV. These findings during the symptom-free period revealed that peripheral vestibular dysfunction was more common than a central deficit.Öğe Posterior reversible encephalopathy Syndrome (PRES): a series of 22 patients(Springer Heidelberg, 2014) Ciftci, S.; Guler, A.; Eraslan, C.; Sirin, H.; Celebisoy, N.; Calli, C.Öğe Posterior reversible encephalopathy syndrome (PRES): a series of 22 patients(Wiley-Blackwell, 2014) Ciftci, S.; Guler, A.; Eraslan, C.; Sirin, H.; Celebisoy, N.; Calli, C.Öğe Theoretical investigation of tenth-value thicknesses of aluminium absorbers(American Institute of Physics Inc., 2019) Sen, M.; Çalık, A.E.; Sirin, H.The half-value thickness (HVT) and the tenth-value thickness (TVT) are used to determine the strength of radiation shielding. The HVT and TVT are the thickness of an absorber sample that will reduce the initial radiation intensity to one-half and one-tenth, respectively. These can be calculated as HVT=ln2/?m and TVT=ln10/?m, using the solution of the standard dI/dx =-?mx attenuation equation. Here, ?m and I are mass attenuation coefficient and radiation intensity, respectively. In this study, the intensity of beta particle that pass through aluminium (Al) absorber has been measured using different isotopes experimentally. An inconsistent has been seen between the TVT values that calculated using standard mathematic and experimental TVT values. To overcome this discrepancy, the standard attenuation equation has been redefined using fractional calculus and resolved. The fractional TVT values consistent with experimental TVT values have been calculated for the suitable fractional derivative orders. © 2019 Author(s).Öğe total plasma exchange in neuromyelitis optica patients: single centre experiences(Springer Heidelberg, 2014) Kilic, I. H.; Guler, A.; Celebisoy, N.; Yuceyar, A. N.; Gokcay, F.; Sirin, H.; Donmez, A.
