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- MakaleAçık Erişim2024Can leisure education effect on screen time and perceived leisure benefits for college students?
Özkara, Abdullah Bora; Mulazimoglu, Olcay; Somoglu, Mustafa Baris; Kirkbir, Fatih; Tokul, Erdi; Aydemir, Burakhan; Senturk, Halil Evren; Dalbudak, Ibrahim; Ozcilingir, Ozgun Mirac
Background: Since children and adolescents usually spend their theoretical course time at schools, they experience many negative effects of inactivity and physical inactivity. They are disadvantaged in terms of facing many health and social problems due to lack of physical activity. This sedentary life increases their exposure to screens and the time they spend sitting. Aim of the study: The first aim of this research is to conduct an experimental study to reduce the excessive screen time of college students with an exercise intervention. The second aim of the study is to examine the perceived benefits of leisure activities of students with an exercise intervention. Methods: In this direction, the study group of the research, which was conducted as an experimental study, consisted of 176 [74 female (42.0%), 102 male (58.0%)] students studying in the department of mathematics at college. In the study, the screen exposure time of students was measured with the Screen time scale for youth and adolescents along with a personal information form. In addition, the Perceived Leisure Benefit Scale scale was used to evaluate the participants' awareness of the benefits obtained from leisure activities. Results and conclusion: According to the findings of the research, it was determined that there was a positive and significant decrease in the screen time of the experimental group participants of students who participated in the research before and after the exercise intervention. In the Leisure Benefit Scale, it was observed that there were significant positive differences in favor of the experimental group.
- MakaleAçık Erişim2012Alcohol Consumption Among Inflammatory Rheumatic Patients: A Survey From Turkey
Çay, H. Fatih; Illeez, Ozge; Kocabas, Hilal; Sezer, Ilhan; Kaptanoglu, Ece; Kaçar, Cahit
Objectives: In this study, we aimed to evaluate alcohol consumption of Turkish rheumatic patients. Patients and methods: A total of 332 subjects [185 males and 147 females; mean ages of 41.2 (95% CI 39.5-43.0) and 45.2 (95% CI 43.4-47.1) years, respectively] with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and healthy controls were questioned regarding their alcohol habits. Alcohol consumers were asked to fill out the Turkish version of the Michigan Alcoholism Screening Test (MAST). Results: A total of 37.3% of all subjects were alcohol consumers. Nearly 50% of males and 20% of females drank alcohol. Rheumatoid arthritis group had the lowest rate of alcohol consumption (23.0%), while healthy controls had the highest rate (45.6%). The mean MAST scores were 3.02 (95% CI: 2.36-3.69) and 3.13 (95% CI: 1.76-4.5) for the AS and RA groups, respectively, indicating statistically lower rate compared to the healthy controls [4.94 (95% CI: 4.14-5.73) (p<0.001)]. An analysis of the MAST scores by categories revealed that most of the alcohol abusers/alcoholics were in the healthy control group. Conclusion: Our results showed that alcohol consumption, an important public health problem, has not been regarded as a major issue for the patients with rheumatic diseases. Further studies are required to evaluate the potential factors which may play a role in the alcohol consumption habits of rheumatic patients.
- MakaleYalnız künye2026Spatio-Temporal Distributions of Seismicity, Stress Evolution, and Tectonomagmatic Signatures of the 2025 Sındırgı Earthquake Swarm, Western Anatolia, Türkiye
Büyüksaraç, Aydin; Senkaya, Mustafa; Alkan, Hamdi; Bektas, Ozcan; Öztürk, Serkan; Pirti, Atinc; Yücel, Mehmet Ali
The Simav Fault Zone (SFZ) in Western Anatolia remains one of the most active tectonic regions in Turkey, and the 2025 S & imath;nd & imath;rg & imath; earthquake swarm has renewed concern regarding evolving seismic hazard. This study analyzes the swarm on the S & imath;nd & imath;rg & imath; Segment using Coulomb stress modelling, spatial distributions of b- and p-value, gravity and magnetic anomalies, geothermal data, and GNSS observations. Coulomb stress calculations show that the M-W = 6.1 and M-W = 6.0 mainshocks produced stress increases of similar to 0.1 bar that effectively loaded adjacent segments of the SFZ, D & uuml;vertepe Fault Zone (DFZ), and Gelenbe Fault Zone (GFZ), guiding the east-southeast and northward migration of aftershocks. Spatial statistics indicate a b-value ranging from 0.6 to 1.3 and a p-value between 0.3 and 1.0. The lower b-values (< 1.0) and p-values (< 0.5) mark high-stress regions near the mainshock, and higher values characterize more stable zones. Gravity anomalies delineate a dense volcanic-ophiolitic body in the southwest and a caldera-like depression south of the SFZ, while magnetic anomalies highlight the structural continuation and interaction of the SFZ with the GFZ. GNSS stations recorded centimetre-to millimetre-scale motions: BAL1 moved similar to 1.34 cm horizontally with minor uplift, DEI1 experienced similar to 1.12 cm displacement with small vertical fluctuations, and KIKA shifted similar to 0.85 cm southwestward with largely stable elevation. Together, these results show that the 2025 swarm was controlled by stress transfer within a mechanically heterogeneous tectonomagmatic system. The identified stress-enhanced corridors along the SFZ and DFZ may act as future nucleation zones, emphasizing the need for sustained monitoring of this evolving fault network.
- MakaleAçık Erişim2026Process Optimization of Spray-Dried Aquafaba and Comparison with Freeze-Drying: Techno-Functional Performance and Structural Attributes
Tunc Odabas, Merve Tugce; Saricaoglu, Furkan Turker; Parlak, Mahmut Ekrem; Akdogan, Arda; Odabas, Halil Ibrahim; Gündogdu, Engin; Simsek, Senay; Atalar, Ilyas
This study aimed to optimize the spray-drying (SD) process for aquafaba and compare the physical and techno-functional properties of the resulting powder with those of its freeze-dried (FD) counterpart. A Box-Behnken design was employed to evaluate the effects of inlet air temperature (150-190 degrees C), air speed (3.5-4.3 m/s), and feed flow rate (0.3-0.5 L/h) on 14 quality responses. The optimized SD conditions were determined to be an inlet air temperature of 189 degrees C, an air speed of 4.2 m/s, and a feed flow rate of 0.3 L/h. Validation experiments demonstrated that the developed models had high predictive capacity, with only a small discrepancy (0.56-5.88%) between the predicted and experimental values. Comparative analysis showed that the optimized SD powder had significantly lower moisture content (2.47%) and water activity (0.18) than the FD powder (3.51% and 0.34, respectively), indicating superior storage stability. In addition, the SD powder exhibited greater whiteness (82.37), higher water solubility (88.44%), and substantially greater foaming capacity (266.67%) than the FD sample (243.33%). Although the FD powder demonstrated better wettability and water absorption capacity because of its porous structure, FTIR spectroscopy and protein secondary structure analysis confirmed that SD preserved the functional integrity of aquafaba. Specifically, SD induced a transition from disordered random-coil structures to more ordered beta-sheet and beta-turn configurations, thereby improving foaming performance. Overall, these findings indicate that optimized spray-drying is a highly efficient and industrially scalable alternative to freeze-drying for producing functional aquafaba powder for use as a plant-based egg substitute.
- MakaleAçık Erişim2023Perception of Higher-Order Affordances for Kicking in Soccer
Peker, Alper Tunga; Böge, Veysel; Bailey, George S.; Wagman, Jeffrey B.; Stoffregen, Thomas A.
We investigated the perception of higher-order interpersonal affordances for kicking that emerged from lower-order personal and interpersonal affordances in the context of soccer. Youth soccer players reported the minimum gap width between two confederates through which they could kick a ball. In Experiment 1, we independently manipulated the egocentric distance of gaps from participants, and the nominal role of the confederates, either as teammates or opponents. In Experiment 2, we additionally varied the direction in which the confederates were facing, either together (i.e., into the gap) or away (i.e., away from the gap). Perceived minimum kickable gap width was larger for farther egocentric distances, when confederates were identified as opponents rather than as teammates, and (in Experiment 2) when confederates faced toward, rather than away from the gap. In both experiments, these main effects were subsumed in statistically significant interactions. We argue that these interactions reveal perception of higher-order interpersonal affordances for kicking that emerged from the simultaneous influence of lower-order affordances. The results are compatible with the hypothesis that these higher-order affordances were perceived, as such, and were not additively combined from independent perception of underlying, lower-order affordances.
- MakaleAçık Erişim2025Recurrent aphthous stomatitis, oxidative stress, and ischemia modified albumin: A cross-sectional study
Öztekin, Aynure; Öztekin, Coskun; Sahin, Humeyra Nursel; Karadeniz, Tuba Betul; Senel, Engin; Caliskan Atac, Damla; Savci, Unsal; Neselioglu, Salim; Erel, Ozcan
Recurrent aphthous stomatitis is an inflammatory disease characterized by painful ulcers on the oral mucosa. Oxidative stress is held responsible for the pathogenesis of this disease of unknown etiology. In oxidative stress, the balance between oxidant-antioxidant substances changes in favor of the oxidative side. Ischaemia modified albumin (IMA) is a new type of albumin. It occurs as a result of factors such as ischemic attacks and oxidative stress. The aim of the study was to compare IMA levels in patients with recurrent aphthous stomatitis with healthy volunteers and to investigate whether IMA has a diagnostic value in the disease. This cross-sectional study included 32 patients with recurrent aphthous stomatitis and 34 healthy volunteers of similar age and sex. Albumin and IMA levels were determined by spectrophotometric albumin cobalt binding assay in venous blood samples on the same day. IMA was expressed as absorbance unit. Receiver operating characteristic analysis was used to determine whether IMA values could be a diagnostic marker for prediction of disease. IMA values of the patient group were significantly higher than IMA values of the control group (P < .001). IMA was statistically significant in the prediction of recurrent aphthous stomatitis (P < .001). The discrimination power for IMA was very good (area under the receiver operating characteristic curve 95% CI = 0.952 [0.897-1.000]). Recurrent aphthous stomatitis, in which oxidative stress plays a role in the etiopathogenesis, is closely associated with high IMA levels. IMA levels may have diagnostic value as an indicator of oxidative stress in the disease.
- MakaleAçık Erişim2024Diatom Communities in the Littoral Sediments of the Robert Island's Lakes, South Shetland Islands, Antarctica
Akar, Bulent; Güney, Aysegul; Özkan, Korhan; Avci, Utku; Kandemir, Raif
The study area is situated at Robert Island, which is located in the South Shetland Islands in the northwest of the Antarctic Peninsula. The diatom samples were taken as part of the Turkish Antarctic Expedition (TAE-II) which took place between March and April 2018. The samples were collected from the surface of sediments (c. 5 cm) at a depth of approximately 20 cm, 50-100 cm from the littoral zones of an inland glacial lake (L1) and three coastal lakes (L2, L3 and L4) situated on glacier-free area on Robert Island. The main objective of this study was to reveal the diversity and the abundance of diatom communities in the littoral sediments of the lakes on Robert Island. The lakes were shallow and oligotrophic freshwater lakes, although the coastal lagoons had a high conductivity and nutrient concentration. Twenty-six diatom taxa belonging to Achnanthes (1), Fragilaria (1), Frustulia (1), Gomphonema (1), Halamphora (1), Hantzschia (1), Hippodonta (1), Humidophila (2), Luticola (3), Melosira (1), Nitzschia (4), Pinnularia (3), Planothidium (2), Psammothidium (2), Stauroneis (1) and Stephanopterobia (1) were identified in the samples from these lakes. The coastal lake L2 showed the highest richness of diatom communities among the in studied lakes, with 21 identified taxa.
- MakaleYalnız künye2011Adakite-like granitoid porphyries in the Eastern Pontides, NE Turkey: Potential parental melts and geodynamic implications
Karsli, Orhan; Ketenci, Murat; Uysal, Ibrahim; Dokuz, Abdurrahman; Aydin, Faruk; Chen, Bin; Kandemir, Raif; Wijbrans, Jan
The tectonic setting of the Eastern Pontides during the late Mesozoic to early Cenozoic remains a subject of debate. Petrogenesis of adakite-like granitoid porphyries plays a critical role in determining the nature of the lower continental crust and mantle dynamics during orogenic processes in the region. Here we describe, for the first time, the late Paleocene to early Eocene adakite-like granitoid porphyries from the northern part of the Eastern Pontides although their counterparts in the southern part have recently been found. The adakitic porphyries, which emplaced into the subduction-related Turonian-Santonian volcanics from northern part of the region, consist of I-type calc-alkaline quartz monzonite-tonalite (SiO2 = 62.89-65.07 wt.%) and high-k calc-alkaline granodiorite-granite associations (SiO2 = 69.06-70.43 wt.%). The former displays peraluminous to metaluminous signatures, whereas the latter shows peraluminous geochemical character. The granite-granodiorite porphyries have high K2O (3.32-3.84 wt.%), and low Na2O (3.48-4.61 wt.%) and MgO (0.91-1.04 wt.%) relative to the quartz monzonite-tonalite association (K2O = 1.50-1.92 wt.%; Na2O = 4.08-6.45 wt.%; MgO = 1.44-2.07 wt.%). Ar-Ar geochronology studies on the amphibole separates reveal that the adakite-like porphyries have a crystallization ages of 51.34 +/- 0.27 to 53.55 +/- 0.34 Ma. Here, we contend that these rocks were formed by partial fusion of a mafic lower continental crust in a collisional phase but not in a subduction setting. All the samples exhibit the typical geochemical characteristics of adakite, that is, high Sr (250-1141 ppm), high Sr/Y ratios (16-147), low Y (6.8-14.8 ppm) and low HREE concentrations; they are similar to adakites formed by slab melting associated with the subduction zone. However, the rocks exhibit heterogeneity in isotopic composition, with I-Sr ranging from 0.70554 to 0.70986, epsilon(Nd) (51 Ma) from -8.5 to -0.9 and Nd model ages from 0.72 to 1.26 Ga. The samples are characterized by relatively high Th, Th/U and no significant Eu anomalies, implying that garnet was stable in their source during partial melting. The compositional diversity between rock groups is probably related to partial melting of heterogeneous lower crustal source. All of the features are inconsistent with a slab-melting origin and slab-related petrogenetic model, but instead, they favor an origin by melting of heterogeneous lower continental crust due to a thermal anomaly that was induced by the upwelling of the asthenosphere through a slab break-off in a collisional setting. These interpretations argue against the evidence for the presence of an early Cenozoic arc setting in the Eastern Pontides. Instead, the early Cenozoic time in the region may be attributed to a geodynamic response to a post-collisional uplift phase that occurred along the continent-continent collision between the Pontide and the Anatolide-Tauride blocks. (C) 2011 Elsevier B.V. All rights reserved.
- MakaleAçık Erişim2026Thermosonication improves the bioactive properties and in vitro bioaccessibility of broccoli juice through integrated RSM and metaheuristic optimization
Arpa Zemzemoglu, Tuba Eda; Tokatli Demirok, Nazan; Türkol, Melikenur; Gürfidan, Remzi; Kilim, Oguzhan; Tokatli, Nazli; Yikmis, Seydi; Mohamed Ahmed, Isam A.; Aljobair, Moneera O.; Yinanç, Abdullah
Broccoli juice is highly nutritious, containing phenolic compounds, chlorophyll derivatives, antioxidants, and other biologically active phytochemicals; however, conventional thermal processing may reduce their stability and bioaccessibility. The aim of this study was to analyse the impact of thermosonication on the following properties of broccoli juice: bioactivity, antioxidant capacity, phenolic profile and in vitro bioaccessibility. Thermosonication conditions were optimized using Response Surface Methodology (RSM) integrated with the Gray Wolf Optimizer (GWO) and Particle Swarm Optimization (PSO) algorithms. Broccoli juice samples were subjected to conventional pasteurization and thermosonication under different processing conditions, and total chlorophyll, ascorbic acid (AA), ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and individual phenolic compounds were evaluated. Digestive stability and post-digestion bioaccessibility were also assessed using a standardized in vitro gastrointestinal digestion model. The developed quadratic models exhibited high statistical significance for TPC and FRAP responses (p < 0.001), with coefficients of determination (R2) of 0.9949 and 0.9853, respectively. The optimum thermosonication conditions were identified as 40 degrees C, 6.75 min, and 64.04% amplitude, under which experimentally validated FRAP and TPC values reached 12.86 mmol TE/L and 149.77 mg GAE/100 ml, respectively. HPLC-DAD analysis showed that gallic acid and naringin were the pre-dominant phenolic compounds, and that thermosonication promoted greater phenolic retention than conventional pasteurization. In vitro digestion results demonstrated that thermosonicated broccoli juice maintained significantly higher levels of TPC, FRAP, chlorophyll, and AA throughout gastrointestinal digestion, with higher TPC recovery (30.45%) than pasteurized samples (26.22%), indicating improved post-digestion bioaccessibility of phenolic compounds. Similar improvements were observed for antioxidant capacity and chlorophyll retention. Furthermore, PSO and GWO optimization results showed strong agreement with RSM predictions, confirming the robustness of the proposed optimization strategy. Overall, thermosonication was shown to effectively and sustainably enhance the functional quality, antioxidant properties, phenolic stability, and digestive bioaccessibility of broccoli juice.
- MakaleAçık Erişim2021Role of the Health System in Combating Covid-19: Cross-Section Analysis and Artificial Neural Network Simulation for 124 Country Cases
Bayraktar, Yuksel; Özyilmaz, Ayfer; Toprak, Metin; Isik, Esme; Büyükakin, Figen; Olgun, Mehmet Firat
In the fight against Covid-19, developed countries and developing countries diverge in success. This drew attention to the discussion of how different health systems and different levels of health spending are effective in combating Covid-19. In this study, the role of the health system in the fight against Covid-19 is discussed. In this context, the number of hospital beds, the number of doctors, life expectancy at 60, universal health service and the share of health expenditures in GDP were used as health indicators. In the study, firstly 2020 data was estimated by using the Artificial Neural Networks simulation method and this year was used in the analysis. The model, with the data of 124 countries, was estimated using the cross-sectional OLS regression method. The estimation results show that the number of hospital beds, number of doctors and life expectancy at the age of 60 have statistically significant and positive effects on the ratio of Covid-19 recovered/cases. Universal health service and share of health expenditures in GDP are not significant statistically on the cases and recovered. Hospital bed capacity is the most effective variable on the recovered/case ratio.
- MakaleYalnız künye2023Effect of oil exposure stages on the heat resistance of Salmonella enterica serovar Enteritidis phage type 30 in peanut flour
Liu, Shuxiang; Qiu, Yan; Ji, Kexin; Ozturk, Samet; Erdogdu, Ferruh; Qin, Wen; Yang, Ren; Wu, Qingping
The oil in low-moisture foods (LMFs) shows protective effects on bacteria during thermal processing. However, the circumstances under which this protective effect strengthens remain unclear. This study aimed to understand which step of the oil exposure to bacterial cells (inoculation, isothermal inactivation, or recovery and enumer-ation step) in LMFs can enhance their heat resistance. Peanut flour (PF) and defatted PF (DPF) were selected as the oil-rich and oil-free LMF models. Salmonella enterica Enteritidis Phage Type 30 (S. Enteritidis) was inoculated into four designated PF groups representing different oil exposure stages. It was isothermally treated to obtain heat resistance parameters. At a constant moisture content (aw,25 degrees C = 0.32 +/- 0.02) and controlled aw,85 degrees C (0.32 +/- 0.02), S. Enteritidis exhibited significantly high (p < 0.05) D values in oil-rich sample groups. For instance, the heat resistance values of S. Enteritidis in the PF-DPF and DPF-PF groups were D80 degrees C of 138.22 +/- 7.45 min and 101.89 +/- 7.82 min; however, the D80 degrees C in the DPF-DPF group was 34.54 +/- 2.07 min. The oil addition after the thermal treatment also helped injured bacterial recovery in the enumeration. For instance, the D80 degrees C, D85 degrees C, and D90 degrees C values in the DFF-DPF oil groups were 36.86 +/- 2.30, 20.65 +/- 1.23, and 7.91 +/- 0.52 min, respectively, which were higher than those in the DPF-DPF group at 34.54 +/- 2.07, 17.87 +/- 0.78, and 7.10 +/- 0.52 min. We confirmed that the oil protected S. Enteritidis in PF in all three stages: desiccation process, heat treatment, and recovery of bacterial cells in plates.
- MakaleAçık Erişim2024Eocene magmatism related to postcollisional extension in the Eastern Pontides (NE Turkiye): 40Ar-39Ar geochronology, geochemistry, and whole-rock Sr-Nd-Pb-Hf isotopes
Aydinçakir, Emre; Yücel, Cem; Kaygusuz, Abdullah; Bilici, Ozgur; Yilmazer, Sinan; Ruffet, Gilles
The mineral chemistry, whole-rock geochemistry, 40 Ar / 39 Ar dating and Sr-Nd-Pb-Hf isotopes of the Eocene Narman (Erzurum) Volcanic rocks in the southeast of the Eastern Pontides Orogenic Belt (EPOB, NE Turkiye) were investigated. The Narman Volcanites consist of basaltic dyke, basaltic lava, and basaltic volcanic breccia facies. Volcanites contain plagioclase (An34-80), 34-80 ), clinopyroxene (Wo38- 38- 47En41-50Fs5-18), En 41-50 Fs 5-18 ), and olivine (Fo 68-90 ) as phenocrystals with magnetite/titanomagnetite microphenocrysts. New 40 Ar- 39 Ar ages suggest that these volcanic rocks erupted between 44.5 +/- 0.1 and 43.4 +/- 0.1 Ma, within the Middle Eocene (Lutetian). Narman Volcanites have calcalkaline character, with medium-high K content. Volcanites are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE), while they are depleted in terms of high field strength elements (HFSE). Chondrite-normalized rare earth element distributions have concave shape with moderate enrichment (LaN/LuN= N /Lu N = 2.78-7.99), leading to consideration that the magmas forming the volcanics derived from similar sources. Isotopically, the rocks in the Narman Volcanites have low-medium initial 87 Sr/ 86 Sr values (0.70405-0.70485), initial 143 Nd/ 144 Nd values (0.512606-0.512848) and positive Nd i (+0.5 - +5.2). Depleted mantle Nd model ages were T DM1 = 0.29-0.62 Ga and T DM2 =0.43-0.83 Ga. (206Pb/204Pb)i, 206 Pb/ 204 Pb) i , (207Pb/204Pb)i, 207 Pb/ 204 Pb) i , and (208Pb/204Pb)i 208 Pb/ 204 Pb) i values vary in the ranges of 18.246-18.709, 15.578-15.616, and 38.225-38.791, respectively. The initial (176Hf/177Hf)i 176 Hf/ 177 Hf) i ratios for the volcanites are between 0.282770 and 0.283013, while the epsilon Hf values range from +7.6 to +9. All the evidence supports the conclusion that the parental magma for the rocks probably derived from an enriched lithospheric mantle, previously metasomatized by fluids derived from subducted slab during asthenospheric upwelling, due to fragmented asymmetric delamination in a postcollisional extensional tectonic environment.
- MakaleYalnız künye2011Migrating magmatism in a continental arc: Geodynamics of the Eastern Mediterranean revisited
Eyuboglu, Yener; Santosh, M.; Dudas, Francis O.; Chung, Sun-Lin; Akaryali, Enver
The eastern Pontide orogenic belt in Turkey offers a critical region to evaluate the geodynamic evolution of the eastern Mediterranean region during the late Mesozoic-Cenozoic. Here we synthesize results from our exhaustive database on the geochemical characteristics of adakitic magmatism from 137 bodies covering 7 domains in the southern zone of eastern Pontides. Together with new Pb-Sr-Nd results, we show that the adakitic magmatism in the eastern Pontide belt is clearly linked to slab window processes during ridge subduction, as against the earlier models that assumed partial melting of a delaminated or thickened lower continental crust following collision. The isotopic compositions display a complex pattern and suggest mixing of multiple source materials such as depleted mantle, enriched lithospheric mantle, and upper crust. We also confirm a southward polarity of subduction as against the previous models that assumed a northward subduction. We supplement our model with evidence for a northward propagation of the adakitic magmatism, spatial and temporal variations in arc magmatism, presence of south-dipping reverse faults and a synthesis of the available paleomagnetic data. Our studies also suggest that the Black-Sea is a remnant of the Tethyan ocean that was situated to the north of the arc during the late Mesozoic-Cenozoic as against the correlation to a late Mesozoic-Cenozoic back-arc basin related to a northward subduction of the Paleo- or Neo-tethyan oceanic lithosphere in alternate models. (C) 2010 Elsevier Ltd. All rights reserved.
- MakaleYalnız künye2016Permo-Carboniferous granitoids with Jurassic high temperature metamorphism in Central Pontides, Northern Turkey
Gücer, Mehmet Ali; Arslan, Mehmet; Sherlock, Sarah; Heaman, Larry M.
In the northern part of the Central Pontides (N Turkey) there are different metamorphic rocks exposed, notably the Devrekani metamorphic rocks. Here, upper amphibolite-lower granulite facies metamorphic rocks contain predominantly paragneiss, orthogneiss and metacarbonate, and to a lesser extent, amphibolite and quartzite, with cross-cutting aplite, pegmatite and granite veins. This is the first report of these rocks and includes new data on the petrochemistry, geochronology and metamorphic evolution of the Devrekani orthogneisses from the Central Pontides. The orthogneisses show five different mineral parageneses with the characteristic mineral assemblage quartz + K-feldspar + plagioclase + biotite +/- hornblende +/- opaque (+/- ilmenite and +/- magnetite), and accessory minerals (zircon, sphene and apatite). These metamorphic rocks exhibit generally granoblastic, lepidogranoblastic and nematolepidogranoblastic with locally migmatitic and relic micrographic textures. They have well-developed centimeter-spaced gneissic banding and display gneissose structure with symmetric, asymmetric and irregular folds. The petrographic features, mineralogical assemblages and weak migmatization reflect high temperature conditions. Thermometric calculations in the orthogneisses indicate metamorphic temperatures reached 744 +/- 33 A degrees C. Field relations, petrography and petrochemistry suggest that the orthogneisses have predominantly granodioritic and some granitic protoliths, that show features of I-type, medium to high-potassic calc-alkaline volcanic arc granitoids. The orthogneisses have high contents of LILEs and low contents of HFSEs with negative Nb and Ti anomalies, which are typical of subduction-related magmas. The orthogneisses also show significant LREE enrichment relative to HREE with negative Eu anomalies (Eu-N/Eu* = 0.33-1.07) with La-N/Lu-N = 6.98-20.47 values. Based on U-Pb zircon dating data, the protoliths are related to Permo-Carboniferous (316-252 Ma) magmatism. It is likely that peak metamorphism took place during the Jurassic as reflected by the U-Pb zircon ages (199-158 Ma) and also 40Ar/39Ar from hornblende/biotite (163-152 Ma). The four biotite 40Ar/39Ar average ages from the rock samples are ca. 156 Ma, suggesting that the metamorphic rocks cooled to 350-400 A degrees C at ca. 156 Ma. Conclusively, the Devrekani metamorphic rocks can be ascribed as products of Permo-Carboniferous continental arc magmatism overprinted by Jurassic metamorphism in the northern Central Pontides.
- MakaleAçık Erişim2025A Dose-Dependent Study Examining Dexmedetomidine's Possible Effects Against Oxidative, Fibrotic, and Apoptotic Damage Induced by Radiation Exposure in Spleen Tissue
Beyazal Polat, Hatice; Yilmaz, Hamit; Kilinc, Kagan; Gülhan, Belemir; Yilmaz Rakici, Sema; Tümkaya, Levent
Objective: This study aimed to investigate the potential splenic tissue damage induced by radiotherapy (RT) and the potential protective effect of different doses of dexmedetomidine on this damage at the histopathological, immunohistochemical, and biochemical levels. Materials and Methods: In our study, Sprague Dawley rats were randomly divided into four groups: Control, Radiotherapy (RT; 8 Gy), RT + Dexmedetomidine 100 mu g/kg (RT-D100), and RT + Dexmedetomidine 200 mu g/kg (RT-D200). A single dose of 8 Gy radiotherapy was administered to each RT group. Spleen tissues were examined histologically with hematoxylin-eosin and immunohistochemically with anti-Caspase-3, anti-TGF-beta 1, and anti-TGF-beta 3 using light microscopy. TBARS and total thiol levels were also analyzed to assess oxidative stress and antioxidant capacity. Results: Histopathological results showed a significant decrease in white pulp diameter, decreased cellular density, and increased congestion in the red pulp in the RT group. Significant fibrosis, sinusoidal dilatation, vacuolization, and amyloid deposition were detected in the white pulp in the RT group. Regarding anti-caspase-3 immunoreactivity, strong positivity increased in the red pulp in the RT group, while a significant increase was observed in the white pulp in both the RT-D100 and RT groups. While the proportion of TGF-beta 1 immunopositive cells did not change significantly in the RT group, they increased significantly in both dexmedetomidine groups (especially RT-D200). TGF-beta 3 expression increased significantly only in the RT-D100 group. In biochemical analyses, TBARS levels increased significantly in the RT-D100 group. Total thiol levels decreased in the RT group and increased in the dexmedetomidine-treated groups. Conclusions: While RT caused histopathological damage and increased oxidative stress in spleen tissue, dexmedetomidine reduced this damage in a dose-dependent manner. The different immunohistochemical profiles of TGF-beta 1 and TGF-beta 3 suggest that these cytokines may have different functions in the spleen. 100 mu g/kg dexmedetomidine stimulates a regenerative response through TGF-beta 3, while 200 mu g/kg dexmedetomidine may provide immune regulation and antioxidative defense through TGF-beta 1.
- MakaleAçık Erişim2014Oxidation of cyanobenzocycloheptatrienes: Synthesis, photooxygenation reaction and carbonic anhydrase isoenzymes inhibition properties of some new benzotropone derivatives
Güney, Murat; Coskun, Ahmet; Topal, Fevzi; Dastan, Arif; Gülçin, Ilhami; Supuran, Claudiu T.
The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51-4.06 mu M). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (K-1: 2.88 +/- 0.86 mu M). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (K-i: 2.51 +/- 0.34 mu M). (C) 2014 Elsevier Ltd. All rights reserved.
- MakaleAçık Erişim2025Athlete's Heart in Women's Contact Sports: Echocardiographic and Strain-Based Insights From Elite Rugby Players
Tunca, Cagatay; Gök, Saner Bahadir; Günes, Ozan; Özkan, Mehmet Taha; Tas, Alperen; Ibis, Ayse Nur Ozkaya; Sahin, Yusuf Bozkurt; Akdogan, Murat; Kivrak, Ahmet; Akbuga, Kursat
Background: Athlete's heart encompasses cardiac adaptations to long-term intensive training. Although male-dominated sports have been widely studied, limited data exist on structural and functional cardiac remodeling in female contact-sport athletes. This study aimed to evaluate cardiac changes in elite female rugby players using conventional and strain echocardiography. Methods: This cross-sectional study included 66 elite female rugby players and 50 sedentary controls. Anthropometric measurements and transthoracic echocardiographic assessments, including speckle tracking-derived global longitudinal strain (GLS), were performed. Linear, multivariable, and partial correlation analyses evaluated associations between GLS, active playing years (APY), and body mass index (BMI). Results: Compared to controls, athletes exhibited increased ventricular diameters, wall thicknesses, and left atrial size, with preserved left ventricular ejection fraction (LVEF). GLS values were significantly lower in rugby players (p < 0.001), though within normal limits. APY and BMI both showed significant inverse correlations with GLS (r = -0.456 and -0.370, respectively). In multivariable analysis, APY (beta = -0.392, p = 0.001) and BMI (beta = -0.225, p = 0.013) independently predicted GLS. Partial correlation confirmed the independent association of APY with GLS (r = -0.412, p = 0.001). GLS showed strong discriminative performance for >= 5 years of play (AUC = 0.816) and moderate performance for BMI >= 24.13 (AUC = 0.666). Conclusion: Elite female rugby athletes demonstrate physiological cardiac remodeling, including reduced GLS associated with training duration and BMI. These findings highlight the need for sex- and sport-specific echocardiographic reference values and further longitudinal research to clarify long-term clinical implications.
- MakaleAçık Erişim2025Geochronological and isotopic data from the adakitic Dodurga Pluton (Central Pontides, N Turkiye): new insights for the geodynamic evolution of the northern Neotethys
Çimen, Okay; Gücer, Mehmet Ali; Simonetti, Antonio; Karaoglan, Fatih
The Dodurga Pluton is located within the Central Pontides (northern Turkiye), has a SW-NE elongation, and consists of granodiorite and dacite porphyry. Previous studies have suggested that this pluton is Triassic in age, and its whole-rock geochemical systematics is consistent with that from adakitic magmatic occurrences rather than the classic arc granitoid suite. This study reports for the first time in situ/whole-rock radiogenic isotopic (Sr, Nd, and Pb) and mica/amphibole Ar-Ar age data to evaluate better its petrogenetic/geodynamic evolution and the chemical nature of mantle source(s). Unlike previous data, combined new in situ zircon U-Pb yield Late Cretaceous crystallization ages of 84.2 +/- 0.9 Ma and 86.9 +/- 0.9 Ma, and the Ar-Ar age data along with apatite fission track measurements suggest magma cooling extending to 82.3 +/- 0.4 Ma and 85.4 +/- 0.4 Ma, respectively. The apatite fission track (AFT) dating results also reveal that this pluton was buried at a depth of 2.5-3 km following a fast-cooling period during the Late Cretaceous and cooled/exhumed over similar to 2 km during the Middle-Late Miocene (15-10 Ma) in a slow cooling phase. The overall data reported here suggest that the Dodurga Pluton represents melts derived from an enriched/metasomatized mantle source that interacted with lower crustal mafic rocks in an active continental margin as a result of northward subduction of the northern branch of the Neotethys Ocean.
- MakaleAçık Erişim2025FinTech driven green energy transition foreign direct investment and ecological footprint in BRICST countries
Ayaydin, Hasan; Ergün, Tolga; Barut, Abdulkadir; Erdem, Azad; Pilatin, Abdulmuttalip
The increasing emphasis on climate change and environmental sustainability worldwide has brought about the convergence and increased focus on financial technologies (FinTech) and green energy initiatives. In light of this, the study's objective is to investigate how FinTech moderates the relationship between the ecological footprint (EF) and green energy transition (GTE) in the BRICS-T nations between 1990 and 2021. This study examines how fintech moderated the GTE and EF in the BRICS-T from 1990 to 2021. We applied the Fully Modified Ordinary Least Squares (FMOLS) and used Dynamic Ordinary Least Squares (DOLS) as the main estimators for longitudinal analysis. In contrast, Driscoll-Kraay was used to verify the robustness of the results under cross-sectional dependence and heteroskedasticity. The results reveal that FinTech indirectly hinders EF by facilitating GTE. The outcomes also show that FinTech significantly constrains EF, while GDP and industrialization worsen EF. The results also confirm the important role of GTE and foreign direct investment (FDI) in reducing CO2 emissions in BRICS-T countries. Lastly, the paper offers policymakers useful recommendations for lowering EF in light of these outcomes. The study suggests establishing appropriate policies and strategies that encourage FinTech platforms to invest in green energy projects, including financial technology, promoting energy-efficient and low-carbon foreign direct investment, and encouraging GTE.
- MakaleAçık Erişim2023An Investigation of the Protective Effect of Rhododendron luteum Extract on Cisplatin-Induced DNA Damage and Nephrotoxicity and Biochemical Parameters in Rats
Turan, Ibrahim; Canbolat, Deniz; Demir, Selim; Kerimoglu, Gokcen; Colak, Fatih; Alemdar, Nihal Turkmen; Mentese, Ahmet; Aliyazicioglu, Yuksel
The nephrotoxicity mechanisms caused by cisplatin (CP), which is used in the treatment of different types of cancer, include several processes, such as DNA damage, apoptosis, inflammation, and oxidative stress. This study investigated the protective effects of Rhododendron luteum leaf extract (RLE) in a rat model of CP -induced nephrotoxicity. Dimethyl sulfoxide extract of RLE was prepared, and its contents were clarified using liquid chromatography-mass spectrometry (LC-MS -MS). Thirty female Wistar Albino rats were divided into five different groups and sacrificed on the seventh day. Biochemical and histopathological analyses were then performed. The presence of quercitrin, quinic acid, chlorogenic acid, protocatechic acid, isoquercitrin, and quercetin was detected in the RLE. While CP significantly increased the levels of oxidative stress, inflammation, and apoptosis markers in the rat kidney tissue and blood samples, treatment with RLE significantly reversed the levels of these parameters in a dose-dependent manner. Total antioxidant status (TAS) values and glutathione (GSH) levels increased significantly in the serum samples from the treatment group compared to the CP group, while blood urea nitrogen (BUN), creatinine, oxidative stress index (OSI), tumor necrosis factor-alpha (TNF-alpha), malondialdehyde (MDA) and total oxidant status (TOS) values decreased significantly. GSH levels increased significantly in the treatment group compared to the CP group, while TNF-alpha, caspase-3 (Casp-3), 8-hydroxy-2'-deoxyguanosine (8-OHdG), OSI, TOS, MDA levels, and damage scores decreased significantly at histopathological examination. In conclusion, RLE exhibited strong protective effects against nephrotoxicity and oxidative damage caused by CP in rats.
