Suleyman Demirel University of Turkey

sdu.edu.kz/
Isparta, Turkey

Süleyman Demirel University is a public university located in Isparta, Turkey. Established in 1992, the university, with around 70.000 students, is the second largest academic institution in Turkey. SDU is known for its programs in agricultural research, medicine, engineering, and business science. The university is approved by the Erasmus programme for participation and funding. SDU is a member of European University Association. Wikipedia.

SEARCH FILTERS
Time filter
Source Type

Nazroglu M.,Suleyman Demirel University of Turkey
Journal of Molecular Neuroscience | Year: 2017

Despite considerable research, the mechanisms of neuropathic pain induced by excessive oxidative stress production and overload calcium ion (Ca2+) entry in dorsal root ganglion (DRG) remain substantially unidentified. The transient receptor potential melastatin 2 (TRPM2) and vanilloid 1 (TRPV1) channels are activated with different stimuli including oxidative stress. TRPM2 and TRPV1 have been shown to be involved in induction of neuropathic pain. However, the activation mechanisms of TRPM2 and TRPV1 via NADPH oxidase and protein kinase C (PKC) pathways are poorly understood. In this study, I investigated the roles of NADPH oxidase and PKC on Ca2+ entry through TRPM2 and TRPV1 channels in in vitro DRG neurons of rats. Rat DRG neurons were used in whole-cell patch clamp experiments. The H2O2-induced TRPM2 current densities were decreased by N-(p-amylcinnamoyl)anthranilic acid (ACA), and dose-dependent capsaicin (CAP) and H2O2-induced TRPV1 currents were inhibited by capsazepine (CPZ). The TRPV1 channel is activated in the DRG neurons by 0.01 mM capsaicin but not 0.001 mM or 0.05 mM capsaicin. TRPM2 and TRPV1 currents were increased by the PKC activator, phorbol myristate acetate (PMA), although the currents were decreased by ACA, CPZ, and the PKC inhibitor, bisindolylmaleimide I (BIM). Both channel currents were further increased by PMA + H2O2 as compared to H2O2 only. In the combined presence of PMA + BIM, no TRPM2 or TRPV1 currents were observed. The CAP and H2O2-induced TRPM2 current densities were also decreased by the NADPH oxidase inhibitors apocynin and N-Acetylcysteine. In conclusion, these results demonstrate a protective role for NADPH oxidase and PKC inhibitors on Ca2+ entry through TRPM2 and TRPV1 channels in DRG neurons. Since excessive oxidative stress production and Ca2+ entry are implicated in the pathophysiology of neuropathic pain, the findings may be relevant to the etiology and treatment of neuropathology in DRG neurons. © 2017, Springer Science+Business Media New York.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: KBBE.2011.1.4-04 | Award Amount: 1.87M | Year: 2012

The provision of public goods (including landscape services) in rural areas is recognized as one of the key topics for the future of agriculture and rural policy. Agriculture plays a major role in landscape management through its complex interlinkages with landscape features. In turn, the Common Agricultural Policy (CAP) remains an important driver of landscape management due to its importance as a determinant of farming activities in the EU. The main objective of the CLAIM project is to provide the knowledge base to support an effective CAP policy design in the direction of improved landscape management, particularly providing insights into the ability of landscape to contribute to the production of added value for society in rural areas. CLAIM is focused in particular on understanding and enhancing the contribution of landscapes management to socio-economic development and agricultural competitiveness in rural areas. This will be based on a pragmatic consideration of landscape services and their analysis through a mixed-method approach, taking into account the wider EU policy strategies (in particular related to innovation and the bioeconomy). The main expected result of the CLAIM project is an evidence-based policy support framework on the different and possible contributions of agriculture and the CAP to landscape management. The framework will be mainly developed and validated through a set of 9 case studies, a strong involvement of stakeholders at different territorial levels and a wide coverage of the perspectives of EU and candidate countries. The framework will finally take the practical form of a web-based manual to be implemented in accordance to stakeholders needs and indications.


Grant
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: SFS-13-2015 | Award Amount: 5.24M | Year: 2016

MyToolBox mobilises a multi-actor partnership (academia, farmers, technology SMEs, food industry and policy stakeholders) to develop novel interventions aimed at achieving a 20-90% reduction in crop losses due to fungal and mycotoxin contamination. MyToolBox will not only pursue a field-to-fork approach but will also consider safe use options of contaminated batches, such as the efficient production of biofuels. A major component of MyToolBox, which also distinguishes this proposal from previous efforts in the area mycotoxin reduction, is to provide the recommended measures to the end users along the food and feed chain in a web-based Toolbox. Cutting edge research will result in new interventions, which will be integrated together with existing measures in the Toolbox that will guide the end user as to the most effective measure(s) to be taken to reduce crop losses. We will focus on small grain cereals, maize, peanuts and dried figs, applicable to agricultural conditions in EU and China. Crop losses using existing practices will be compared with crop losses after novel pre-harvest interventions including investigation of genetic resistance to fungal infection, cultural control, the use of novel biopesticides (organic-farming compliant), competitive biocontrol treatment and development of forecasting models to predict mycotoxin contamination. Research into post-harvest measures including real-time monitoring during storage, innovative sorting of crops using vision-technology and novel milling technology will enable cereals with higher mycotoxin levels to be processed without breaching regulatory limits in finished products. Research into the effects of baking on mycotoxin levels will provide better understanding of process factors used in mycotoxin risk assessment. Involvement of leading institutions from China are aimed at establishing a sustainable cooperation in mycotoxin research between the EU and China.


Sofiyev A.H.,Suleyman Demirel University of Turkey
Composite Structures | Year: 2012

In this study, the non-linear vibration of truncated conical shells made of functionally graded materials (FGMs) has been investigated using the large deformation theory with von Karman-Donnell-type of kinematic non-linearity. The material properties of FGMs are assumed to vary continuously through the thickness of the shell. The fundamental relations, the non-linear motion and compatibility equations of the FGM truncated conical shell are derived. By using Superposition method, Galerkin method and Harmonic balance method, the non-linear vibration of an FGM truncated conical shell is analyzed. Finally, the influences of compositional profiles and variation of shell geometry on the dimensionless non-linear frequency parameter and the variation of ratio of the non-linear frequency to the linear frequency are investigated. The present results are compared with the available data for a special case. © 2012 Elsevier Ltd.


Kizilkan O.,Suleyman Demirel University of Turkey
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2011

This study presents performance modeling of an experimental refrigeration system driven by variable speed compressor using artificial neural networks (ANNs) with small data sets. Controlling the rotational speed of compressor with a frequency inverter is one of the best methods to vary the capacity of refrigeration system. For this aim, an experimental refrigeration system was designed with a frequency inverter mounted on compressor electric motor. The experiments were made for different compressor electric motor frequencies. Instead of several experiments, the use of ANNs had been proposed to determine the system performance parameters based on various compressor frequencies and cooling loads using results of experimental analysis. The backpropagation learning algorithm with two different variants was used in the network. In order to train the neural network, limited experimental measurements were used as training and test data. The best fitting training data set was obtained with eight neurons in the hidden layer. The results showed that the statistical error values of training were obviously within acceptable uncertainties. Also the predicted values were very close to actual values. © Sila Science.


Naziroglu M.,Suleyman Demirel University of Turkey
Journal of Receptors and Signal Transduction | Year: 2012

Background: Catalase catalyzes the reduction of H2O2 to water and it can also remove organic hydroperoxides. Nervous system in body is especially sensitive to free radical damage due to rich content of easily oxidizible fatty acids and relatively low content of antioxidants including catalase. Recent studies indicate that reactive oxygen species actually target active channel function, in particular TRP channels. I review the effects of catalase on Ca2+ signaling and on TRP channel activation in neuroglial cells such as microglia and substantia nigra. Materials: Review of the relevant literature and results from recent our basic studies, as well as critical analyses of published systematic reviews were obtained from the pubmed and the Science Citation Index. Results: It was observed that oxidative stress-induced activations of TRPM2, TRPC3, TRPC5 and TRPV1 cation channels in neuronal cells are modulated by catalase, suggesting antioxidant-dependent activation/inhibition of the channels. I provide also, a general overview of the most important oxidative stress-associated changes in neuronal mitochondrial Ca2+ homeostasis due to oxidative stress-induced channel neuropathies. Catalase incubation induces protective effects on rat brain mitochondrial function and neuronal survival. A decrease in catalase activity through oxidative stress may have an important role in etiology of Parkinson's disease and sensory pain. Conclusion: The TRP channels can be activated by oxidative stress products, opening of nonspecific cation channels would result in Ca2+ influx, and then elevation of cytoplasmic free Ca 2+ could stimulate mitochondrial Ca2+ uptake. Catalase modulates oxidative stress-induced Ca2+ influx and some TRP channels activity in neuronal cells. © 2012 Informa Healthcare USA, Inc.


Naziroglu M.,Suleyman Demirel University of Turkey
Neurochemical Research | Year: 2011

The Na+ and Ca 2+-permeable melastatin related transient receptor potential 2 (TRPM2) channels can be gated either by ADP-ribose (ADPR) in concert with Ca 2+ or by hydrogen peroxide (H 2O 2), an experimental model for oxidative stress, binding to the channel's enzymatic Nudix domain. Since the mechanisms that lead to TRPM2 gating in response to ADPR and H 2O 2 are not understood in neuronal cells, I summarized previous findings and important recent advances in the understanding of Ca 2+ influx via TRPM2 channels in different neuronal cell types and disease processes. Considering that TRPM2 is activated by oxidative stress, mediated cell death and inflammation, and is highly expressed in brain, the channel has been investigated in the context of central nervous system. TRPM2 plays a role in H 2O 2 and amyloid β-peptide induced striatal cell death. Genetic variants of the TRPM2 gene confer a risk of developing Western Pacific amyotropic lateral sclerosis and parkinsonism-dementia complex and bipolar disorders. TRPM2 also contributes to traumatic brain injury processes such as oxidative stress, inflammation and neuronal death. There are a limited number of TRPM2 channel blockers and they seem to be cell specific. For example, ADPR-induced Ca 2+ influx in rat hippocampal cells was not blocked by N-(p-amylcinnomoyl) anthralic acid (ACA), the IP3 receptor inhibitor 2-aminoethoxydiphenyl borate or PLC inhibitor flufenamic acid (FFA). However, the Ca 2+ entry in rat primary striatal cells was blocked by ACA and FFA. In conclusion TRPM2 channels in neuronal cells can be gated by either ADPR or H 2O 2. It seems to that the exact relationship between TRPM2 channels activation and neuronal cell death still remains to be determined. © Springer Science+Business Media, LLC 2010.


A study has been made to determine the critical time parameters of truncated conical shells with functionally graded coatings (FGCs) and subjected to a time dependent axial load in the large deformation. The method of solution utilizes Superposition principle and Galerkin procedure. Donnell-Karman type non-linear differential equations for the truncated conical shell with FGCs are derived and reduced to ordinary differential equation with the time dependent coefficient. The Runge-Kutta method and modified Budiansky-Roth criterion are then used to solve this non-linear differential equation with the time dependent coefficient. Finally, effects of compositional profiles of coatings, variation of truncated conical shell parameters and loading speed on the dimensionless linear and non-linear critical time parameters have been studied. Comparing the results of this study with those in the literature validates the present analysis. © 2013 Elsevier Ltd. All rights reserved.


Sofiyev A.H.,Suleyman Demirel University of Turkey
Composite Structures | Year: 2014

The vibration and buckling of sandwich cylindrical shells covered by different types of coatings, such as functionally graded (FG), metal and ceramic coatings and subjected to a uniform hydrostatic pressure using first order shear deformation theory (FOSDT) is discussed. Four types of sandwich cylindrical shells are considered. The volume fraction of FG coatings varies according to a simple power law function of thickness coordinate, while that of the core equals unity. The effective material properties of FG coatings are assumed to be graded in the thickness direction according to an exponential law distribution. The equations of motion of FG sandwich cylindrical shells are deduced using the FOSDT. The closed-form solutions for non-dimensional frequencies and critical hydrostatic pressures are obtained. The influences of compositional profiles of coatings, shear stresses and sandwich shell characteristics on the non-dimensional frequencies and critical hydrostatic pressures for FG and homogeneous sandwich cylindrical shells are discussed. © 2014 Elsevier Ltd.


Sofiyev A.H.,Suleyman Demirel University of Turkey
Composite Structures | Year: 2014

In this study, the non-linear vibration of laminated non-homogenous orthotropic truncated conical shell is investigated. It is assumed that the Young's moduli, shear modulus and density of the layers of the shell vary exponentially through the thickness direction. The basic equations of laminated non-homogenous orthotropic truncated conical shells are derived using the large deformation theory with von Karman-Donnell-type of kinematic non-linearity. The non-linear basic equations are reduced to the non-linear differential equation depending on the time using the superposition principle and Galerkin method. This equation is solved using semi-inverse method and is found the frequency-amplitude relationship. Finally, carrying out some computations, the effects of non-homogeneity, number and ordering of layers, and conical shell characteristics on frequency-amplitude characteristics have been studied. © 2013 Elsevier Ltd.

Loading Suleyman Demirel University of Turkey collaborators
Loading Suleyman Demirel University of Turkey collaborators