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Öğe Ameliorating effect of quercetin on acute pentylenetetrazole induced seizures in rats(E-Century Publishing Corp, 2014) Sefil, Fatih; Kahraman, Ibrahim; Dokuyucu, Recep; Gokce, Hasan; Ozturk, Atakan; Tutuk, Okan; Aydin, MehmetObjective: The aim of the study to elicit effects of pure quercetin in pentylenetetrazole (PTZ) and picrotoxin induced seizures. Materials and methods: Each animal group was divided into six groups and composed of six rats. Rats were assigned to the following experiments and groups (G): (G1) PTZ 45 mg/kg + DMSO; (G2) PTZ 45 mg/kg + 5 mg/kg quercetin; (G3) PTZ 45 mg/kg + 10 mg/kg quercetin; (G4) PTZ 45 mg/kg + 20 mg/kg quercetin; (G5) PTZ 45 mg/kg + 40 mg/kg quercetin; (G6) Picrotoxin 5 mg/kg + DMSO; (G7) Picrotoxin 5 mg/kg + 10 mg/kg quercetin; (G8) Picrotoxin 5 mg/kg + 20 mg/kg quercetin. In all groups quercetin were injected 30 min before PTZ and picrotoxin applications. Results: Compared to PTZ, quercetin significantly prolonged onset of the seizure in 10 mg/kg (P < 0.05) and reduced the seizure stage in 10 mg/kg quercetin injected group (P < 0.01). Compared to PTZ, quercetin also declined the generalized seizure duration at 10 mg/kg (P < 0.01) and 20 mg/kg (P < 0.05) doses. At the doses of 5 mg/kg and 40 mg/kg quercetin there were no significant changes in seizure parameters. Development of picrotoxin induced seizures is slower than in PTZ. Quercetin was found to be unable to prevent seizure in picrotoxin induced seizures. Surprisingly, quercetin also significantly reduced the onset of seizures at the dose of 20 mg/kg (P < 0.05). Conclusion: quercetin (at doses of 10 and 20 mg/kg i.p) prevented seizures in PTZ (45 mg/kg i.p) induced seizures. Especially, 10 mg/kg PTZ prolonged onset of seizures, reduced the seizure duration and seizure severity score in comparison with control group. At a higher (40 mg/kg) dose quercetin failed to prevent PTZ induced seizures. In addition 20 mg/kg quercetin significantly reduced the onset of seizures that suggest a preconvulsive effect. 20 mg/kg quercetin reduced the onset of picrotoxin induced seizures. In picrotoxin model, it may be claimed that quercetin at higher doses accelerate the epileptic activity owing to its antagonistic effect on GABAA. Further investigations are needed to explore the mechanisms of the antiepileptic and preconvulsant effects of quercetin.Öğe Beneficial effect of erdosteine on methotrexate-induced testicular toxicity in mice(Sage Publications Inc, 2010) Oktar, Sueleyman; Gokce, Ahmet; Aydin, Mehmet; Davarci, Muersel; Meydan, Sedat; Ozturk, Oktay Hasan; Koc, AhmetMethotrexate is used to treat certain types of cancer of the breast, skin, head and neck, or lung. Methotrexate can cause serious or life-threatening side effects on liver, lungs, kidneys, and immune system. Methotrexate chemotherapy causes testicular damage in humans. The aim of this study was to investigate the possible protective role of erdosteine on testicular toxicity of methotrexate in mice. Twenty-six male mice were divided into four groups as follows: group 1, control; group 2, erdosteine-treated; group 3, methotrexate-treated; and group 4, methotrexate + erdosteine treated. On the first day of experiment, a single dose of methotrexate was intraperitoneally administered to groups 3 and 4, although a daily single dose of erdosteine was orally administered to group 2 and 4 for 7 days. At the end of the experiment, the testes of the animals were removed and weighed. The levels of total antioxidant capacity and total oxidative stress, and myeloperoxidase activity in the methotrexate group were higher than the control group (p<0.05). Lipid peroxidation levels were not changed in methotrexate group compared with control group. In conclusion, erdosteine could effectively protect the testes in methotrexate-induced toxicity.Öğe Diurnal photosynthesis, water use efficiency and light use efficiency of wheat under Mediterranean field conditions(Triveni Enterprises, 2008) Evrendilek, Fatih; Asher, Jiftah Ben; Aydin, MehmetPhotosynthesis and transpiration rates of wheat leaves (Triticum aestivum L.) were measured at 30 min intervals under Mediterranean field conditions, using Photosynthesis Monitor system (PM-48M). The dynamics of net photosynthetic rate (PN), transpiration rate (ET), water use efficiency (WUE), light use efficiency (LUE), stomatal conductance (gs), photosynthetically active radiation (PAR), air temperature (T), relative humidity (RH), and atmospheric CO2 concentration (Catm) were quantified at five rainfed wheat sites with the same stages of development (midflowering) along south-to-north and east-to-west transects for eight days in April. Diurnal PN (3.6 to 6.6 ?mol m-2 s -1), PAR (392 to 564 ?mol m-2 sec-1), LUE (0.006 to 0.015) and WUE (0.0001 to 0.011) did not vary significantly across all five wheat sites (p>0.05). PN and ET were strongly coupled and highly correlated with PAR (p<0.001). Best multiple linear regression (MLR) models accounted for 92% of variations in PN as a function of PAR and ET, and 90% in ET as a function of PAR and RH (p<0.001). PN exhibited a peak at mid-morning, and a photosynthetic midday depression under the limiting effects of high evaporative demand. Diurnal variations in WUE and LUE showed a bimodal behavior with the maximum values in early morning and late afternoon. As the impacts of global climate change become increasingly felt, continuous measurements of climate-crop-soil-management interactions under natural conditions play a pivotal role not only in exploring changes in ecophysiological properties of strategic crops for food security such as wheat but also in devising preventive and mitigative management practices to ensure sustained agricultural productivity. © Triveni Enterprises.Öğe Effect of sulfite on antioxidant enzymes and lipid peroxidation in normal and sulfite oxidase-deficient rat erythrocytes(Springer, 2010) Ozturk, Oktay Hasan; Oktar, Suleyman; Aydin, Mehmet; Kucukatay, VuralSulfite and related chemical such as sulfite salts and sulfur dioxide has been used as a preservative in food and drugs. This molecule has also been generated from the catabolism of sulfur-containing amino acids. Sulfite is a very reactive and potentially toxic molecule and has to be detoxified by the enzyme sulfite oxidase (SOX). The aim of this study was to investigate the effects of ingested sulfite on erythrocyte antioxidant status by measuring glucose-6-phosphate dehydrogenase (G-6-PD), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities and oxidant status by measuring thiobarbituric acid reactive substances (TBARS) in normal and SOX-deficient rats. Rats were assigned to four groups (n = 10 rats/group) as follows; control (C), sulfite (CS), deficient (D), and deficient+sulfite (DS). SOX deficiency was established by feeding rats a low molybdenum diet and adding to their drinking water 200 ppm tungsten (W). Sulfite (25 mg/kg) was administered to the animals via their drinking water. At the end of 6 weeks, Erythrocyte G-6-PD, SOD, and GPx but not CAT activities were found to be significantly increased with and without sulfite treatment in SOX-deficient groups. Sulfite treatment alone was also significantly increased erythrocytes' SOD activity in CS group compared to control. TBARS levels were found to be significantly increased in CS and DS groups and decreased in D group. When SOX-deficient rats treated with sulfite, TBARS level was still higher than other groups. In conclusion, these results suggested that erythrocyte antioxidant capacity, a defense mechanism against the oxidative challenge, increased by endogenous and exogenous sulfite due to its oxidant nature. This increase was also observed in CS and DS groups but it was insufficient to prevent lipid peroxidation.Öğe Effects of ?-Glucan Pretreatment on Acetylsalicylic Acid-Induced Gastric Damage: An Experimental Study in Rats(Elsevier Science Inc, 2010) Ozkan, Orhan Veli; Ozturk, Oktay Hasan; Aydin, Mehmet; Yilmaz, Nigar; Yetim, Ibrahim; Nacar, Ahmet; Oktar, SuleymanBACKGROUND: NSAIDs have been found to induce gastrointestinal tract damage. Recently, it has been suggested that this might be mediated by lipid peroxidation. OBJECTIVE: The aim of this study was to assess the potential protective effects of beta-glucan against acetylsalicylic acid (ASA)-induced gastric damage by means of its antioxidant capacity in an experimental rat model. METHODS: Thirty-two male Wistar albino rats (200-250 g) were randomized into 4 groups consisting of 8 rats each. The beta-glucan group received 50 mg/kg beta-glucan once a day for 10 days and 30 minutes before anesthesia. The ASA group received saline once a day for 10 days and 300 mg/kg (20 mg/mL) ASA as a single dose, 4 hours before anesthesia. The ASA+beta-glucan group was administered 50 mg/kg beta-glucan once a day for 10 days and 30 minutes before anesthesia. Additionally, 300 mg/kg (20 mg/mL) ASA was administered as a single dose, 4 hours before anesthesia. The control group received saline once a day for 10 days and 30 minutes before anesthesia. All medications were administered by intragastric gavage. The stomach from each rat was dissected and divided into 2 parts for histologic and biochemical analysis. Gastric tissue malondialdehyde (MDA), nitric oxide (NO) levels, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were determined for oxidative parameter analysis. RESULTS: The gastroprotective and antioxidant effects of beta-glucan appeared to attenuate the ASA-induced gastric tissue damage. Compared with the control group, MDA and NO levels and CAT and GSH-Px activities were significantly increased in the stomachs of ASA-treated rats (MDA, 4.12 [0.44] to 13.41 [1.05] mu mol/L; NO, 8.04 [7.25-9.10] vs 30.35 [22.34-37.95] mu mol/g protein; CAT, 0.050 [0.004] to 0.083 [0.003] k/g protein; GSH-Px, 0.57 [0.42-0.66] to 1.55 [1.19-1.76] U/L; all, P < 0.001), whereas SOD activity was significantly decreased in the same group (291 [29] to 124 [61 U/mL; P < 0.001). In the ASA+beta-glucan group, MDA and NO levels and CAT and GSH-Px activities were found to be significantly lower, while SOD activity was found to be significantly higher, in comparison with the ASA-treated group (all, P < 0.001). CONCLUSION: beta-Glucan appeared to attenuate the gastric damage caused by ASA in these rats. (Curr Ther Res Clin Exp. 2010;71:369-383) (C) 2010 Elsevier HS Journals, Inc.Öğe Effects of ammonia and allopurinol on rat hippocampal NMDA receptors(Wiley, 2010) Yonden, Zafer; Aydin, Mehmet; Kilbas, Aynur; Demirin, Hilmi; Sutcu, Recep; Delibas, NamikAmmonia is considered to be the main agent responsible for hepatic encephalopathy which progressively leads to altered mental status. N-methyl-D-aspartate (NMDA) is an ionotropic glutamate receptor, which is involved in synaptogenesis, memory and neurotoxicity. The aim of this study was to investigate the effects of ammonia intoxication and allopurinol, a xanthine oxidase (XO) inhibitor, on NMDA receptor subunits, NR2A and NR2B, in the hippocampus of rats. Thirty-six male rats were divided into three groups (n = 12/group) as follows: (1)control group (phosphate buffered saline (PBS) solution); (2)ammonia group (ammonium acetate, 2.5 mmol/kg), (3)ammonia + allopurinol group (ammonium acetate, 2.5 mmol/kg, allopurinol, 50 mg/kg). Each rat received intraperitoneal injection for 28 days. Western Blotting technique was used for detecting NR2A and NR2B expressions. Both NR2A and NR2B subunit expressions decreased 27 and 11%, respectively, in ammonia group with respect to the control group. Ammonium acetate decreased significantly in NR2A subunit expressions in the hippocampus (p < 0.01). Administration of ammonia + allopurinol caused statistically significant increases in NR2A subunit expressions compared to the ammonia group (p < 0.001). The down-regulation of NMDA receptors caused by ammonium acetate suggest that these receptors may play role in the process of hepatic encephalopathy and using allopurinol may have some protective effects in ammonia toxicity. Copyright (C) 2010 John Wiley & Sons, Ltd.Öğe Enhanced Growth Rate and Reduced Water Demand of Crop Due to Climate Change in the Eastern Mediterranean Region(Springer International Publishing Ag, 2019) Ben-Asher, Jiftah; Yano, Tomohisa; Aydin, Mehmet; Garcia y Garcia, AxelThe specific objectives of this study were to: (a) test the reliability of a regional climate model (RCM) as a tool for climate change projection in the Eastern Mediterranean, (b) compare the observed yield variables of maize and wheat in the region with results of two crop models, (c) compare the models DSSAT and SWAP and (d) use DSSAT and SWAP to generate future productivity of wheat and maize under the A2 global warming scenario. Reference evapotranspiration was highly correlated with the models with average r(2) = 0.98 and a unit slope. The two models accurately predicted observed dry mass production (DMP) and leaf area index (LAI) of wheat and maize. The correlations strengthen the legitimacy of DSSAT, SWAP and RCM to serve as predicting models for future climate change on a regional scale. A simulation was carried out to describe the effects of climate change on crop growth and irrigation water requirements for a wheat-maize-wheat cropping sequence. Climate change scenarios were projected using data of three general circulation models (CGCM2, ECHAM4 and MRI) for the period of 1990-2100 and one RCM for the period of 2070-2079. Daily RCM data were consistent with actual meteorological data in the region and therefore were used for computations of present and future water balance and crop development. Predictions derived from the models about changes in irrigation and crop growth covered the period of 2070-2079 relative to a baseline period of 1994-2003. The effects of climate change on wheat and maize water requirements and yields were predicted using the detailed crop growth subroutine of the DSSAT (Decision Support System for Agrotechnology Transfer) and SWAP (Soil-Water-Atmosphere-Plant) models. Precipitation was projected to decrease by about 163, 163 and 105 mm during the period of 1990-2100 under the A2 scenario of the CGCM2, ECHAM4 and MRI models respectively (an average of about 1.3 mm/year). The models projected a temperature rise of 4.3, 5.3 and 3.1 degrees C, by the year 2100. An increase in temperature may result in a higher evaporative demand of the atmosphere under combined doubling CO2 concentration and temperature rise by about 2 degrees C for the period of 2070-2079. The temperature rise accelerated crop development and shortened the growing period by a maximum of thirteen days for wheat and nine days for maize during the period 2070-2079. When yield and available water (rain + applied irrigation) were normalised by extension of the growing period with respect to the baselines years, DMP of maize increased by 1-3 ton ha(-1) and that of wheat by 3-4 ton ha(-1). Consequently, water use efficiency (WUE) increased for both crops. It was concluded, therefore, that the effect of increased temperature and doubling CO2 on agro-productivity may be positive. This positive effect can be explained if elevated temperature meets the optimal level of a crop response to temperature. Effects of elevated CO2 on crop tolerance to water stress may counteract the expected negative effects of rising temperature. Increased atmospheric CO2 levels have important physiological effects on crops such as the increase in photosynthetic rate, which is associated with higher yield and WUE, at least for some cereal crops in the Eastern Mediterranean.Öğe Estimation of actual soil evaporation using E-DiGOR model in different parts of Turkey(Academic Journals, 2009) Onder, Derya; Aydin, Mehmet; Onder, SermetPenman-Monteith Equation was applied to determine potential soil evaporation using standard data of the meteorological stations at 14 locations from 2001 to 2003. Actual evaporation calculations for different climatic conditions were carried out using the E-DiGOR model developed by Aydin (2008). For comparisons of climatic types, the same soil properties were assumed in calculations. The results showed that the model was suitable for calculating potential and actual soil evaporation rates in different locations with satisfactory accuracy. Owing to high variability of both precipitation and potential evaporation, the actual soil evaporation in different parts of Turkey can change from 263 to 592.7 mm/year. The actual soil evaporation, as calculated with the model, accounted for 34.2 to 83.3% of the incoming precipitation.Öğe Falling Dynamics of SARS-CoV-2 as a Function of Respiratory Droplet Size and Human Height(Springer Heidelberg, 2020) Aydin, Mehmet; Evrendilek, Fatih; Savas, Seckin Aydin; Aydin, Ismail Erkan; Evrendilek, Deniz ErenPurpose The purpose of this study is to quantify the motion dynamics of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods Three physical models of Newton's and Stokes's laws with(out) air resistance in the calm air are used to determine the falling time and velocity regimes of SARS-CoV-2 with(out) a respiratory water droplet of 1 to 2000 micrometers (mu m) in diameter of an infected person of 0.5 to 2.6 m in height. Results The horizontal distance travelled by SARS-CoV-2 in free fall from 1.7 m was 0.88 m due to breathing or talking and 2.94 m due to sneezing or coughing. According to Newton's laws of motion with air resistance, its falling velocity and time from 1.7 m were estimated at 3.95 x 10(-2)m s(-1)and 43 s, respectively. Large droplets > 100 mu m reached the ground from 1.7 m in less than 1.6 s, while the droplets >= 30 mu m fell within 4.42 s regardless of the human height. Based on Stokes's law, the falling time of the droplets encapsulating SARS-CoV-2 ranged from 4.26 x 10(-3)to 8.83 x 10(4) s as a function of the droplet size and height. Conclusion The spread dynamics of the COVID-19 pandemic is closely coupled to the falling dynamics of SARS-CoV-2 for which Newton's and Stokes's laws appeared to be applicable mostly to the respiratory droplet size >= 237.5 mu m and <= 237.5 mu m, respectively. An approach still remains to be desired so as to better quantify the motion of the nano-scale objects.Öğe Impact of climate change on irrigation demand and crop growth in a Mediterranean environment of Turkey(Mdpi, 2007) Yano, Tomohisa; Aydin, Mehmet; Haraguchi, TomokazuA simulation study was carried out to describe effects of climate change on crop growth and irrigation water demand for a wheat-maize cropping sequence in a Mediterranean environment of Turkey. Climate change scenarios were projected using data of the three general circulation models-GCMs (CGCM2, ECHAM4 and MRI)-for the period of 1990 to 2100 and one regional climate model-RCM-for the period of 2070 to 2079. Potential impacts of climate change based on GCMs data were estimated for the A2 scenario in the Special Report on Emission Scenarios (SRES). The forcing data for the boundary condition of the RCM were given by the MRI model. Daily CGCM2 and RCM data were used for computations of water balance and crop development. Predictions derived from the models about changes in irrigation and crop growth in this study covered the period of 2070 to 2079 relative to the baseline period of 1994 to 2003. The effects of climate change on water demand and on wheat and maize yields were predicted using the detailed crop growth subroutine of the SWAP (Soil-Water-Atmosphere-Plant) model. Precipitation was projected to decrease by about 163, 163 and 105 mm during the period of 1990 to 2100 under the A2 scenario of the CGCM2, ECHAM4 and MRI models, respectively. The CGCM2, ECHAM4 and MRI models projected a temperature rise of 4.3, 5.3 and 3.1 degrees C, respectively by 2100. An increase in temperature may result in a higher evaporative demand of the atmosphere. However, actual evapotranspiration (ETa) from wheat cropland under a doubling CO2 concentration for the period of 2070 to 2079 was predicted to decrease by about 28 and 8% relative to the baseline period based on the CGCM2 and RCM data, respectively. According to these models, irrigation demand by wheat would be higher for the same period due to a decrease in precipitation. Both ETa and irrigation water for maize cropland were projected to decrease by 24 and 15% according to the CGCM2, and 28 and 22% according to the RCM, respectively. The temperature rise accelerated crop development but shortened the growing period by 24 days for wheat and 9 days for maize according to the CGCM2 data. The shortened growth duration with a higher temperature reduced the biomass accumulation of both crops regardless of CO2-fertilization effect. With the combined effect of CO2-fertilization and increased temperature, the CGCM2 and RCM projections resulted in an increase by 16 and 36% in grain yield of wheat and a decrease by about 25% and an increase by 3% in maize yield, respectively.Öğe Implications of climate change for evaporation from bare soils in a Mediterranean environment(Springer, 2008) Aydin, Mehmet; Yano, Tomohisa; Evrendilek, Fatih; Uygur, VeliThe purpose of this study was to predict quantitative changes in evaporation from bare soils in the Mediterranean climate region of Turkey in response to the projections of a regional climate model developed in Japan (hereafter RCM). Daily RCM data for the estimation of reference evapotranspiration (ETr) and soil evaporation were obtained for the periods of 1994-2003 and 2070-2079. Potential evaporation (E-p) from bare soils was calculated using the Penman-Monteith equation with a surface resistance of zero. Simulation of actual soil evaporation (E-a) was carried out using Aydin model (Aydin et al., Ecological Modelling 182:91-105, 2005) combined with Aydin and Uygur (2006, A model for estimating soil water potential of bare fields. In Proceedings of the 18th International Soil Meeting (ISM) on Soils Sustaining Life on Earth, Managing Soil and Technology, Sanliurfa, 477-480pp.) model of predicting soil water potential at the top surface layer of a bare soil, after performances of Aydin model (R-2 = 94.0%) and Aydin and Uygur model (R-2 = 97.6) were tested. The latter model is based on the relations among potential soil evaporation, hydraulic diffusivity, and soil wetness, with some simplified assumptions. Input parameters of the model are simple and easily obtainable such as climatic parameters used to compute the potential soil evaporation, average diffusivity for the drying soil, and volumetric water content at field capacity. The combination of Aydin and Aydin and Uygur models appeared to be useful in estimating water potential of soils and E-a from bare soils, with only a few parameters. Unlike ETr and E-p projected to increase by 92 and 69 mm (equivalent to 8.0 and 7.3% increases) due to the elevated evaporative demand of the atmosphere, respectively, E-a from bare soils is projected to reduce by 50 mm (equivalent to a 16.5% decrease) in response to a decrease in rainfall by 46% in the Mediterranean region of Turkey by the 2070s predicted by RCM, and consequently, to decreased soil wetness in the future.Öğe Interactive Effects of Elevated CO2 and Climate Change on Wheat Production in the Mediterranean Region(Springer International Publishing Ag, 2019) Kapur, Burcak; Aydin, Mehmet; Yano, Tomohisa; Koc, Mujde; Barutcular, CelaleddinGlobal climate change could be harmful to agriculture. In particular, water availability and irrigation development under changed climatic conditions already pose a growing problem for crop production in the Mediterranean region. Wheat is the major significant crop in terms of food security. Therefore, in relation to these issues, this review gives an overview of climate change effects on wheat production in the Mediterranean environment of Turkey. Future climate data generated by a general circulation model (e.g., CGCM2) and regional climate models (e.g., RCM/MRI, CCSR-NIES and TERCH-RAMS) have been used to quantify the wheat growth and the soil-water-balance around the Eastern Mediterranean region of Turkey. The effects of climate change on the water demand and yield of wheat were predicted using the detailed crop growth subroutine of the SWAP (Soil-Water-Atmosphere-Plant). The Soil evaporation was estimated using the E-DiGOR (Evaporation and Drainage investigations at Ground of Ordinary Rainfed-areas) model. This review revealed that the changes in climatic conditions and CO2 concentration have caused parallel changes in the wheat yield. A close correspondence between measured and simulated yield data was obtained. The grain yield increased by about 24.7% (measured) and 21.9% (modelled) under a two-fold CO2 concentration and the current climatic conditions. However, this increase in the yield was counteracted by a temperature rise of 3 degrees C. Wheat biomass decreases under the future climatic conditions and the enhanced CO2 concentration, regardless of the model used. Without CO2 effects, grain yield also decreases for all the models. By contrast, the combined impact of elevated CO2 and increased temperature on grain yield of wheat was positive, but varied with the climatic models. Among the models, the CCSR-NIES and TERCH-RAMS denote the highest (24.9%) and lowest (6.3%) increases in grain yield respectively. The duration of the regular crop-growing season for wheat was 24, 21, and 27 days shorter as calculated for the future, mainly caused by the projected air temperature rise of 2.2, 2.4, and 3 degrees C for a growing period by the 2070s for CGCM2, CCSR-NIES and TERCH-RAMS respectively. The experimental results show large increases in the water use efficiency of wheat, due to the increases in CO2 concentration and air temperature. Despite the increased evaporative demand of the atmosphere, the increases in water use efficiency can be attributed to the shorter growing days and a reduction in the transpiration due to stomata closure. Unlike reference evapotranspiration and potential soil evaporation, actual evaporation from bare soils was estimated to reduce by 16.5% in response to a decrease in rainfall and consequently soil wetness in the future, regardless of the increases in the evaporative demand. It can be concluded that to maintain wheat production in the future, the water stress must be managed by proper irrigation management techniques.Öğe Letrozole induces hepatotoxicity without causing oxidative stress: the protective effect of melatonin(Taylor & Francis Ltd, 2011) Aydin, Mehmet; Oktar, Suleyman; Ozkan, Orhan Veli; Alcin, Ergul; Ozturk, Oktay Hasan; Nacar, AhmetAim. The aim of this study was to determine the effects of letrozole (LTZ), an aromatase inhibitor (AI), and melatonin (MLT) on hepatic function and oxidative stress in female rats. Material and methods. A total of 32 female rats were divided equally into four groups (n = 8). Control group received saline (0.5 ml/day, oral gavage). LTZ was administered to rats by daily oral gavage at 1 mg/kg dose. LTZ + MLT group was given LTZ (1 mg/kg, oral gavage) plus MLT (0.5 mg/kg/day, s.c.). MLT group was given MLT (0.5 mg/kg/day) by s.c. injection. The activities of superoxide dismutase (SOD) and catalase (CAT) and malondialdehyde (MDA) levels were measured in liver tissue. Total antioxidant capacity (TAC), total oxidant status (TOS), ALT, AST, GGT, ALP, LDH, bilirubin, BUN, creatinine, total cholesterol (TC), high-density lipoprotein (HDL) and triglyceride (TG) were assayed in serum samples. Results. The oxidative stress, parameters did not differ between groups. LTZ administration increased hepatic function parameters such as AST, LDH, ALP, bilirubin and MLT improved the disturbances of hepatic function. LTZ caused minimal histological changes in liver tissue and MLT treatment reversed those dejenerations. Discussion. LTZ may cause hepatotoxicity without inducing oxidative stress and MLT restores hepatic activity.Öğe A model for Evaporation and Drainage investigations at Ground of Ordinary Rainfed-areas(Elsevier Science Bv, 2008) Aydin, MehmetQuantification of water losses through evaporation and drainage from bare soils in and and semi-arid regions is very important for an effective management strategy to conserve soil water. In this study, a model for Evaporation and Drainage investigations at Ground of Ordinary Rainfed-areas (hereafter E-DiGOR) is presented. Daily potential evaporation (E-p) from bare soils was calculated using the Penman-Monteith equation with a surface resistance of zero. Actual soil evaporation (E,,) was computed according to Aydin et al. [Aydin, M., Yang, S.L., Kurt, N., Yano, T., 2005. Test of a simple model for estimating evaporation from bare soils in different environments. Ecol. Model. 182 (1), 91-105; Aydin, M., Yano, T, Evrendilek, F., Uygur, V, 2008. Implications of climate change for evaporation from bare soils in a Mediterranean environment. Environ. Monit. Assess. 140,123-130]. Deep drainage (D) was simply calculated by the mass balance, taking field capacity into account. In order to test the performance of the model mainly for drainage estimations, a micro-lysimer experiment was carried out under field conditions. The experimental terrain was nearly flat, with no appreciable slope. Estimated and measured water balance components such as actual evaporation (R-2 = 91.4%; P < 0.01.), drainage (R-2 = 88.5%; P < 0.01) and soil water storage (R-2 = 89.7%; P < 0.01) were in agreement. This agreement supported the model hypothesis, thus rendering the model useful in estimating soil evaporation, drainage and water storage in an interactive way with a few parameters. Once the estimated and measured data from the experiment had been compared for validation, simulations were carried out continuously for the period of 1994-2006 in a semi-arid environment of Turkey. Ep rates were lower during the winter season because of the lesser evaporative demand of the atmosphere. However, Ea rates were mainly found to be functions of the rainfall pattern, and presumably soil wetness in addition to atmospheric evaporative demand. D volumes below 120 cm soil depth were high during rainy months, with a peak in January. Annual E-P varied between 850.6 and 909.8 mm during the period of 13 years. E. ranged from 248.0 to 392.9 mm with a mean annual value of 302.5 mm. D substantially varied inter-annually (150.5-757.4 mm) depending on the intensity and frequency of rainfall events and especially antecedent soil wetness. The next logical step in model development would be the inclusion of runoff for sloping lands. (C) 2008 Elsevier B.V. All rights reserved.Öğe A model for indoor motion dynamics of SARS-CoV-2 as a function of respiratory droplet size and evaporation(Springer, 2021) Aydin, Mehmet; Savas, Seckin Aydin; Evrendilek, Fatih; Aydin, Ismail Erkan; Evrendilek, Deniz ErenA simplified model has been devised to estimate the falling dynamics of severe acute respiratory syndrome corona-virus 2 (SARS-CoV-2)-laden droplets in an indoor environment. Our estimations were compared to existing literature data. The spread of SARS-CoV-2 is closely coupled to its falling dynamics as a function of respiratory droplet diameter (1 to 2000 mu m) of an infected person and droplet evaporation. The falling time of SARS-CoV-2 with a respiratory droplet diameter of about 300 mu m from a height of 1.7 m remained almost the same among the Newtonian lift equation, Stokes's law, and our simplified model derived from them so as to account for its evaporation. The evaporative demand peaked at midday which was ten times that at midnight. The evaporating droplets <= 6 mu m lost their water content rapidly, making their lifetimes in the air shorter than their falling times. The droplets <= 6 mu m were able to evaporate completely and remained in the air for about 5 min as droplet nuclei with SARS-CoV-2.Öğe Modeling and computer simulation of drainage, evaporation, and runoff (dear) from bare soils(Parlar Scientific Publications, 2020) Aydin, Mehmet; Aydin, Baran; Polat, VeyselAn improved model and its computer program for Drainage, Evaporation and Runoff (DEaR) from bare soils are presented. The model, which is the successor of the model originally known as E-DiGOR, adequately represents the physical processes important in estimating actual soil evaporation, soil water storage, direct surface runoff, infiltrated rainfall, and subsurface flow. The model is useful for quantifying these components of soil water balance with a few parameters, and for the descriptions and predictions of the past, present and future dynamics if climate data are available. Although the physical credibility of the model is quite high, a consistent set of values suitable for the calculations is required. The input variables of the computer program are climate data (sunshine duration, air-temperature, relative humidity, wind speed, and precipitation) and environmental data/soil properties (albedo, psychrometric constant, latitude, fraction of radiation, height for resistance, tortuosity, average diffusivity for drying soil, volumetric water content at field capacity, air-dry water content, threshold potential, reset threshold, profile depth, initial water content of the profile, porosity, slope gradient, and ratio of saturated hydraulic conductivity to maximum rainfall intensity) to account for specific soil-climate combinations. The computer program developed is a useful tool for a fast and precise simulation, and consists of three modules. The computer program has been developed as a MATLAB™ application. The software can be obtained upon request. © 2020 Parlar Scientific Publications. All rights reserved.Öğe MODELING AND COMPUTER SIMULATION OF DRAINAGE, EVAPORATION, AND RUNOFF (DEAR) FROM BARE SOILS(Parlar Scientific Publications (P S P), 2020) Aydin, Mehmet; Aydin, Baran; Polat, VeyselAn improved model and its computer program for Drainage, Evaporation and Runoff (DEaR) from bare soils are presented. The model, which is the successor of the model originally known as E-DiGOR, adequately represents the physical processes important in estimating actual soil evaporation, soil water storage, direct surface runoff, infiltrated rainfall, and subsurface flow. The model is useful for quantifying these components of soil water balance with a few parameters, and for the descriptions and predictions of the past, present and future dynamics if climate data are available. Although the physical credibility of the model is quite high, a consistent set of values suitable for the calculations is required. The input variables of the computer program are climate data (sunshine duration, air-temperature, relative humidity, wind speed, and precipitation) and environmental data/soil properties (albedo, psychrometric constant, latitude, fraction of radiation, height for resistance, tortuosity, average diffusivity for drying soil, volumetric water content at field capacity, air-dry water content, threshold potential, reset threshold, profile depth, initial water content of the profile, porosity, slope gradient, and ratio of saturated hydraulic conductivity to maximum rainfall intensity) to account for specific soil-climate combinations. The computer program developed is a useful tool for a fast and precise simulation, and consists of three modules. The computer program has been developed as a MATLAB (TM) application. The software can be obtained upon request.Öğe Prospective Evaluation of 140 Patients With Brucellosis in the Southern Region of Turkey(Lippincott Williams & Wilkins, 2007) Savas, Lutfu; Onlen, Yusuf; Savas, Nazan; Yapar, Ali; Aydin, Mehmet; Tugal, OnderThe aim of this study was to asses the epidemiological, clinical, and laboratory characteristics of brucellosis in Adana region, Turkey. In this prospective study, a total of 140 patients with brucellosis were investigated in terms of spread of infection; seasonal, age, and sex distribution; clinical and laboratory characteristics; depression and anxiety rates; relapse rates; and response to different treatment combinations. One hundred two patients (72.9%) were female, and 38 patients (27.1%) were male; mean age was 45.81 +/- 15.62 years, ranging from 2 to 77 years. Twenty-five patients (17.8%) had history of contact with animals, and 31 patients (22.1%) had history of consumption of raw milk and/or its products. The highest seasonal distribution was observed during summer. Malaise (95.0%), sweating (85.7%), and arthralgia (85.0%) were the major presenting symptoms. The most common physical examination findings were fever (52.9%), hepatomegaly (20.7%), and splenomegaly (12.1%). Osteoarticular involvement, orchitis, and iridocyclitis were observed in 64.9%, 38.0% (of male patients), and 0.7% of the patients, respectively. Scintigraphy was performed for 114 patients who have focal joint and bone complaints and findings. Beck Depression Inventory and State-Trait Anxiety Inventory testing were applied to 98 patients with brucellosis, and depression was observed in 37.8% of these patients. The total point of State Anxiety Inventory testing was 46.21 +/- 12.87, and the total point of Trait Anxiety Inventory testing was 46.98 +/- 10.11. Either the depression rates or points of State Anxiety Inventory testing and Trait Anxiety Inventory testing in patients with brucellosis were statistically higher than in the control group. In 134 patients, initial standard tube agglutination testing titer was 1/160 or more. Brucella melitensis was found positive in 22 patients. Relapse rate was 3.5%. Brucellosis continues to be a health problem in countries where consumption of unpasteurized dairy products and stockbreeding are common.Öğe THE PROTECTIVE EFFECTS OF PEPTIDE YY AND GHRELIN IN ACUTE BILIARY PANCREATITIS(Carbone Editore, 2014) Aydogan, Akin; Akkucuk, Seckin; Ozkan, Orhan Veli; Aydin, Mehmet; Motor, Sedat; Ugur, Mustafa; Oruc, CemAim: Glzrelin and peptide YY are gut hormones that have an anti-inflammatory effect by inhibiting proinflammatory cytokines. We aimed to determine the anti-inflammatory and protective effects of ghrelin and Peptide YY. Methods: The study group included 28 patients with acute biliary pancreatitis and 38 controls. Ghrelin, peptide YY, IL-6, TNF-alpha, amylase, lipase, glucose, alanine aminotransferase, aspartate aminotransferase, leucocyte count, and hematocrit were measured three times in each patient and once in the control group. Results: Ghrelin levels tended to increase as treatment continued, but still were below the levels in the control group. On the other hand, peptide YY levels in all of the patient samples were higher than in the control group (p>0.001). Conclusion: Ghrelin is proposed as a protective hormone for acute pancreatitis. Exogenous ghrelin exhibits protective activity in caerulein-induced pancreatitis. All previous in vivo and in vitro studies have reported that exogenous PYY administration inhibited izzflammation and had protective effects. This study indicates for the first time that endogenous PYY has protective effects on pancreatitis via the inhibition of inflammation, and that these effects are stronger than the effects of ghrelin.Öğe The protective effects of peptide YY and ghrelin in acute biliary pancreatitis(Acta Medica Mediterranea, 2014) Aydogan, Akin; Akkucuk, Seckin; Ozkan, Orhan Veli; Aydin, Mehmet; Motor, Sedat; Ugur, Mustafa; Oruc, CemAim: Ghrelin and peptide YY are gut hormones that have an anti-inflammatory effect by inhibiting proinflammatory cytokines. We aimed to determine the anti-inflammatory and protective effects of ghrelin and Peptide YY. Methods: The study group included 28 patients with acute biliary pancreatitis and 38 controls. Ghrelin, peptide YY, IL-6, TNF-?, amylase, lipase, glucose, alanine aminotransferase, aspartate aminotransferase, leucocyte count, and hematocrit were measured three times in each patient and once in the control group. Results: Ghrelin levels tended to increase as treatment continued, but still were below the levels in the control group. On the other hand, peptide YY levels in all of the patient samples were higher than in the control group (p>0.001). Conclusion: Ghrelin is proposed as a protective hormone for acute pancreatitis. Exogenous ghrelin exhibits protective activity in caerulein-induced pancreatitis. All previous in vivo and in vitro studies have reported that exogenous PYY administration inhibited inflammation and had protective effects. This study indicates for the first time that endogenous PYY has protective effects on pancreatitis via the inhibition of inflammation, and that these effects are stronger than the effects of ghrelin.
