TR-Dizin İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14720/5

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The Cissoid of Diocles in the Lorentz-Minkowski Plane
(Tubitak Scientific & Technological Research Council Turkey, 2019) Baydas, Senay; Karakas, Bulent
This article presents the cissoid of Diodes and the cissoid of two circles with respect to origin in the Lorentz-Minkowski plane.
A Class of Banach Algebras Whose Duals Have the Schur Property
(1999) Mustafayev, H.; Ülger, A.
Call a commutative Banach algebra A a γ-algebra if it contains a bounded group Λ such that aco(Λ) contains a multiple of the unit ball of A. In this paper, first by exhibiting several concrete examples, we show that the class of γ-algebras is quite rich. Then, for a γ-algebra A, we prove that A* has the Schur property iff the Gelfand spectrum Σ of A is scattered iff A* = ap(A) iff A* = Span(Σ). © TÜBİTAK.
Clinical, Demographic, and Radiological Characteristics of Patients Demonstrating Antibodies Against Myelin Oligodendrocyte Glycoprotein
(Galenos Publ House, 2024) Koc, Sumeyye; Sen, Sedat; Terzi, Yuksel; Kizilay, Ferah; Demir, Serkan; Aksoy, Durdane Bekar; Terzi, Murat
Background: Optic neuritis, myelitis, and neuromyelitis optica spectrum disorder (NMOSD) have been associated with antibodies against myelin oligodendrocyte glycoprotein-immunoglobulin G (anti-MOG-IgG). Furthermore, patients with radiological and demographic features atypical for multiple sclerosis (MS) with optic neuritis and myelitis also demonstrate antibodies against aquaporin-4 and anti-MOG-IgG. However, data on the diagnosis, treatment, follow-up, and prognosis in patients with anti-MOG-IgG are limited. Aims: To evaluate the clinical, radiological, and demographic characteristics of patients with anti-MOG-IgG. Study Design: Multicenter, retrospective, observational study. Methods: Patients with blood samples demonstrating anti-MOG-IgG that had been evaluated at the Neuroimmunology laboratory at Ondokuz May & imath;s University's Faculty of Medicine were included in the study. Results: Of the 104 patients with anti-MOG-IgG, 56.7% were women and43.3% were men. Approximately 2.4% of the patients were diagnosed with MS, 15.8% with acute disseminated encephalomyelitis (ADEM), 39.4% with NMOSD, 31.3% with isolated optic neuritis, and 11.1% with isolated myelitis. Approximately 53.1% of patients with spinal involvement at clinical onset demonstrated a clinical course of NMOSD. Thereafter, 8.8% of these patients demonstrated a clinical course similar to MS and ADEM, and 28.1% demonstrated a clinical course of isolated myelitis. The response to acute attack treatment was lower and the disability was higher in patients aged > 40 years than patients aged < 40 years at clinical onset. Oligoclonal band was detected in 15.5% of the patients. Conclusion: For patients with NMOSD and without anti-NMO antibodies, the diagnosis is supported by the presence of anti-MOG-IgG. Furthermore, advanced age at clinical onset, Expanded Disability Status Scale (EDSS) score at clinical onset, spinal cord involvement, and number of attacks may be negative prognostic factors in patients with anti-MOG-IgG.
Difference Method for a Singularly Perturbed Initial Value Problem
(1998) Amiraliyev, G.M.
In this paper we construct a completely exponentially fitted finite difference scheme for the initial value problem with small parameter by first and second derivatives. We prove the first order uniform convergence of the scheme in the sense of discrete maximum norm. Numerical results are presented. © TÜBİTAK.
The Effect of Sildenafil on Recuperation From Sciatic Nerve Injury in Rats
(Galenos Publ House, 2016) Korkmaz, Mehmet Fatih; Parlakpinar, Hakan; Ceylan, Mehmet Fethi; Ediz, Levent; Samdanci, Emine; Kekilli, Ersoy; Sagir, Mustafa
Background: Severe functional and anatomical defects can be detected after the peripheral nerve injury. Pharmacological approaches are preferred rather than surgical treatment in the treatment of nerve injuries. Aims: The aim of this study is to perform histopathological, functional and bone densitometry examinations of the effects of sildenafil on nerve regeneration in a rat model of peripheral nerve crush injury. Study Design: Animal experiment. Methods: The study included a total of thirty adult Sprague-Dawley rats that were divided into three groups of ten rats each. In all rats, a crush injury was created by clamping the right sciatic nerve for one minute. One day before the procedure, rats in group 1 were started on a 28-day treatment consisting of a daily dose of 20 mg/kg body weight sildenafil citrate given orally via a nasogastric tube, while the rats in group 2 were started on an every-other-day dose of 10 mg/kg body weight sildenafil citrate. Rats from group 3 were not administered any drugs. Forty-two days after the nerve damage was created, functional and histopathological examination of both sciatic nerves and bone densitometric evaluation of the extremities were conducted. Results: During the rotarod test, rats from group 3 spent the least amount of time on the rod compared to the drug treatment groups at speeds of 20 rpm, 30 rpm and 40 rpm. In addition, the duration for which each animal could stay on the rod throughout the accelerod test significantly reduced in rats from group 3 compared to rats from groups 1 and 2 in the 4-min test. For the hot-plate latency time, there were no differences among the groups in either the basal level or after sciatic nerve injury. Moreover, there was no significant difference between the groups in terms of the static sciatic index ( SSI) on the 42nd day ( p=0.147). The amplitude was better evaluated in group 1 compared to the other two groups ( p<0.05). Under microscopic evaluation, we observed the greatest amount of nerve regeneration in group 1 and the lowest in group 3. However, this difference was not statistically significant. Moreover, there was no significant difference in the bone mineral density (BMD) levels among the groups. Conclusion: We believe that a daily single dose of sildenafil plays an important role in the treatment of sciatic nerve damage and bone healing and thus can be used as supportive clinical treatment.
Hardy-Copson Type Inequalities for Nabla Time Scale Calculus
(Tubitak Scientific & Technological Research Council Turkey, 2021) Kayar, Zeynep; Kaymakcalan, Billur
This paper is devoted to the nabla unification of the discrete and continuous Hardy?Copson type inequalities. Some of the obtained inequalities are nabla counterparts of their delta versions while the others are new even for the discrete, continuous, and delta cases. Moreover, these dynamic inequalities not only generalize and unify the related ones in the literature but also improve them in the special cases.
Langevin Delayed Equations With Prabhakar Derivatives Involving Two Generalized Fractional Distinct Orders
(Tubitak Scientific & Technological Research Council Turkey, 2024) Aydin, Mustafa
This paper is devoted to defining the delayed analogue of the Mittag-Leffler type function with three parameters and investigating a representation of a solution to Langevin delayed equations with Prabhakar derivatives involving two generalized fractional distinct orders, which are first introduced and investigated, by means of the Laplace integral transform. It is verified by showing the solution satisfies the introduced system. Special cases which are also novel are presented as examples. The findings are illustrated with the help of the RLC circuits.
New Psychoactive Substance 5-Meo in Vivo Acute Toxicity and Hystotoxicological Study
(Galenos Publ House, 2021) Altunci, Yusuf Ali; Aydogdu, Melike; Acikgoz, Eda; Guven, Ummu; Dukagac, Fahriye; Atasoy, Asli; Akgur, Serap Annette
Background: The hallucinogenic tryptamine analog 5-methoxy-N-methyl-N-isopropyltryptamine (5-MeO-MiPT) causes social problems worldwide. There are several studies on the metabolism; however, not more studies were found in the literature on acute toxicity. Aims: To report the acute toxicity of 5-MeO-MiPT in mice, followed by quantitative toxicological analysis of blood and organs, hystotoxico-logical and immunohistochemical analysis of tissues and cells. Study design: Animal experiment Methods: In vivo experiments were performed using CD1 adult female mice (n=26). Animals were caged in 4 groups randomly. First group was a control (n=3). Second group was vehicle control (n=3) and injected 150 mu L of blank solution (50% dimethyl sulfoxide in saline /0.9% of NaCl). While for acute toxicity experiments, 5-MeO-MiPT was added to a blank solution in order to obtain a dose of 0.27 mg/kg in 150 mu L injection (n=10) and the last group were injected 2.7 mg/kg 5-MeO-MiPT in a 150 mu L injection (n=10). Quantitative toxicological analysis, hystotoxicological and immunohistochemical analysis were performed. Results: In the toxicological analysis, 5-MeO-MiPT was found negative in biological samples which were control, vehicle control, and 0.27 mg/kg dose mice groups. 5-MeO-MiPT was found 2.7-13.4 ng/mL in blood, 11-29 ng/g in kidney, 15.2-108.3 ng/g in liver, and 1.5-40.6 ng/g in the brain in 2,7 mg/kg injected group. In a low dose of the 5-MeO-MiPT liver section, compared with normal tissues, the difference in staining was statistically significant (p<0.0001). In high-dose of 5-MeO-MiPT, H-score showed that the increase in the number of Caspase-3 positive cells was significant compared to the control (p<0.05). In high-dose of 5-MeO-MiPT, intense Caspase-3 immunoreactivity was observed and the increase in the number of Caspase-3 positive cells compared to the control was statistically significant (p<0.05). In brain section, the statistics of the results obtained from the H-score showed that the increase in the number of Caspase-3 positive cells was significant compared to the control (p=0.0183). In vehicle control liver section, there were few Caspase-8 positive cells characterized by a light brown appearance (p=0.0117). In the high-dose 5-MeO-MiPT group, the numbers of positive cells at low and high doses of 5-MeO-MiPT group were statistically significant compared to the control (p<0.05). In the high-dose 5-MeO-MiPT group, Caspase-8 immunoreactivity was detected in the glomerular structures. Compared to control, the increase in Caspase-8 immunoreactivity was found to be statistically significant (p<0.05). Conclusion: Low-dose 5-MeO-MiPT did not cause any serious histopathological effects on the liver, kidney, and brain. High doses induce apoptotic cell death through caspase activity.
A Note on Double Sequences of Fuzzy Numbers
(1996) Savaş, E.
In this paper we introduce double convergent sequences of fuzzy numbers and we also study the space of double convergent sequences of fuzzy numbers. © TÜBİTAK.
A Note on Simple Trinomial Units in U1(Zcp)
(Tubitak Scientific & Technological Research Council Turkey, 2020) Gorentas, Necat
In this paper, some new notions are defined about the unit group U-1(ZG) of a finite group G. Especially, notion of simple unit is defined by using the number of elements in its support and absolutely small coefficients of the unit. Units are classified as monomial, binomial, trinomial and k-nomial, level, unit with level l and simple unit. We have shown triviality of monomial units and nonexistence of binomial units in the unit group U-1(ZG) of an arbitrary finite group G. Some basic results and examples are posed about simple units and simple trinomial units in U-1(ZC(p)) of a cyclic group C-p, where p >= 5.
On Non-Homogeneous Riemann Boundary Value Problem
(2000) Kutlu, K.
In this paper we consider non-homogeneous Riemann boundary value problem with unbounded oscillating coefficients on a class of open rectifiable Jordan curve. © TÜBİTAK.
On the Distribution of Coefficients of Half-Integral Weight Modular Forms and the Bruinier-Kohnen Conjecture
(Tubitak Scientific & Technological Research Council Turkey, 2021) Inam, Ilker; Demirkol Ozkaya, Zeynep; Tercan, Elif; Wiese, Gabor
This work represents a systematic computational study of the distribution of the Fourier coefficients of cuspidal Hecke eigenforms of level Gamma 0(4) and half-integral weights. Based on substantial calculations, the question is raised whether the distribution of normalised Fourier coefficients with bounded indices can be approximated by a generalised Gaussian distribution. Moreover, it is argued that the apparent symmetry around zero of the data lends strong evidence to the Bruinier-Kohnen conjecture on the equidistribution of signs and even suggests the strengthening that signs and absolute values are distributed independently.
Regional Clinical and Biochemical Differences Among Patients With Primary Hyperparathyroidism
(Galenos Publ House, 2017) Makay, Ozer; Ozcinar, Beyza; Simsek, Turgay; Arici, Cumhur; Gungor, Bulent; Ozbas, Serdar; Gulluoglu, Bahadir M.
Background: Environmental habitat may play a role in clinical disparities of primary hyperparathyroidism (pHPT) patients. Aims: To compare preoperative clinical symptoms and associated conditions and surgical findings in patients with pHPT, living in different geographical regions from the Black Sea, Mediterranean and Anatolia regions. Study Design: Retrospective, clinical-based multicentric study of 694 patients with pHPT. Methods: Patients from 23 centers and 8 different geographical regions were included. Data related to baseline demographics, clinical, pathologic and treatment characteristics of 8 regions were collected and included age, gender, residential data, symptoms, history of fracture, existence of brown tumor, serum total Ca and p levels, serum parathormone (PTH) levels, serum 25-OH vitamin D levels, bone mineral density, size of the resected abnormal parathyroid gland(s), histology, as well as the presence of ectopia, presence of dual adenoma, and multiple endocrine neoplasia (MEN)- or familial-related disease. Results: The median age was 54. Asymptomatic patient rate was 25%. The median PTH level was 232 pg/mL and serum total Ca was 11.4 mg/dL. Eighty-seven percent of patients had an adenoma and 90% of these had a single adenoma. Hyperplasia was detected in 79 patients and cancer in 9 patients. The median adenoma size was 16 mm. Significant parameters differing between regions were preoperative symptoms, serum Ca and p levels, and adenoma size. All patients from South-East Anatolia were symptomatic, while the lowest p values were reported from East Anatolia and the largest adenoma size, as well as highest Ca levels, were from Bulgaria. Conclusion: Habitat conditions vary between geographical regions. This affects the clinicopathological features of patients with pHPT.
The Role of Cardiac Ganglia in the Prevention of Coronary Atherosclerosis: an Analytical Examination of Cholesterol-Fed Rabbits
(Galenos Publ House, 2020) Koza, Yavuzer; Aydin, Mehmet Dumlu; Bayram, Ednan; Sipal, Sare; Altas, Ender; Soyalp, Celaleddin; Koza, Enise Armagan
Background: The heart is innervated by the autonomic nervous system, which contributes to the control of the heart's rhythm and coronary circulation. It has been suggested that the cardiac fibers of the vagus nerve play important roles in controlling circulatory functions and in protecting against atherosclerotic pathologies in coronary arteries. Aims: To investigate the presence of atherosclerotic differences in the coronary arteries of cholesterol-fed rabbits by measuring the density of cardiac ganglia neurons. Study Design: Animal experiment. Methods: This study was conducted using 45 male rabbits. Over a period of 16 weeks, they were kept on an atherogenic diet of water ad libitum and high fat (8.6%) containing saturated fatty acids with 205 mg/kg of cholesterol (1%) per day. Then, their hearts were removed and examined by histopathological methods. Atherosclerotic plaques of the main coronary arteries were examined using the Cavalieri method. Atherosclerosis index values (AIVs) were estimated as the wall surface area/plaque surface area, and the results were analyzed with the Kruskal-Wallis and Mann-Whitney U tests. Results: While the average atherosclerosis index value was estimated to be <= 8% in 21 animals, the atherosclerosis index value was 9-20% in animals with minor plaque detection (n=11) and >= 20% in animals with major plaque detection (n=10). Increased atherosclerosis index values were more common in animals with low neuron densities than in animals with high neuron densities (p<0.017). Conclusion: The low neuron density of the cardiac ganglia in cholesterol-fed rabbits is associated with an increased atherosclerotic plaque incidence and volume.
Segal Algebra as an Ideal in Its Second Dual Space
(1999) Mustafayev, H.S.
For a locally compact group G, let S(G) be a symmetric Segal algebra. We prove that S(G) is an ideal in its second dual space if and only if G is compact, where the second dual is equipped with an Arens multiplication. © TÜBİTAK.
Some Ergodic Properties of Multipliers on Commutative Banach Algebras
(Tubitak Scientific & Technological Research Council Turkey, 2019) Mustafayev, Heybetkulu; Topal, Hayri
A commutative semisimple regular Banach algebra Sigma(A) with the Gelfand space Sigma(A) is called a Ditkin algebra if each point of Sigma(A) boolean OR {infinity} is a set of synthesis for A. Generalizing the Choquet-Deny theorem, it is shown that if T is a multiplier of a Ditkin algebra A, then {phi is an element of A* : T* phi = phi} is finite dimensional if and only if card F-T is finite, where F-T = {gamma is an element of Sigma(A) : (T) over cap (gamma) = 1} and (T) over cap is the Helgason-Wang representation of T.
Some Estimates on the Exponential Stability of Solutions of Nonlinear Neutral Type Systems With Periodic Coefffiicients
(Tubitak Scientific & Technological Research Council Turkey, 2023) Altun, Yener
In this present study, we pay attention to a class of nonlinear neutral type systems (NNSs) with periodic coefficients and construct some assumptions guaranteeing the exponential stability (ES) of the trivial solutions of the system considered. To get specific conditions guaranteeing the ES, we use a modified Lyapunov functional. In conclusion, we get some estimates for the exponential decay of the solutions at infinity with the constructed sufficient conditions. We give two examples to demonstrate the applicability of the results obtained with the constructed assumptions.

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