Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Bulut, Hasan(53)
- Baskonus, Haci Mehmet(52)
- Alataş, Mevlüt(39)
- Gul, Muhammet(39)
- Serdar, Osman(38)
- Güler, Ömer(37)
- Akkurt, Nevzat(31)
- Benzer, Fulya(30)
- Sulaiman, Tukur Abdulkadir(29)
- Yucesan, Melih(29)
- Zengin, Gokhan(29)
- Kocabaş, Mehmet(28)
- Topal, Murat(26)
- Batan, Nevzat(25)
- Kök, Mediha(25)
- Ezer, Tülay(24)
- Paksoy, Mehmet Yavuz(24)
- Yildirim, Ozal(23)
- Tekin, H.O.(22)
- Utku, Anıl(22)
- ALMisned, Ghada(21)
- Ince, Muharrem(21)
- Öbek, Erdal(21)
- Erten, Fusun(20)
- Aslan, Naim(19)
- Celik, Erkan(19)
- Yildirim, Numan(19)
- Cakilcioglu, Ugur(18)
- Dal, Murat(18)
- Dal, Nursel Alp(18)
- Sahin, Kazim(18)
- Özkaynak, Fatih(18)
- Aslan, Alper(17)
- Erata, Hüseyin(17)
- Orhan, Cemal(17)
- Ergen, Burhan(16)
- Tanyol, Mehtap(16)
- Demir, Yakup(15)
- Etli, Serkan(15)
- Işık, Erdem(15)
Yayınlar
- BildiriAçık Erişim2021Deep Neural Network Trained on Surface ECG Improves Diagnostic Accuracy of Prior Myocardial Infarction over Q Wave Analysis
Yildirim, Ozal; Baloglu, Ulas B; Talo, Muhammed; Ganesan, Prasanth; Tung, Jagteshwar S; Kang, Guson; Tooley, James; Alhusseini, Mahmood I.; Baykaner, Tina; Wang, Paul J.
Clinical screening of myocardial infarction is important for preventative treatment and risk stratification in cardiology practice, however current detection by electrocardiogram Q-wave analysis provides only modest accuracy for assessing prior cardiac events. We set out to evaluate the ability of a deep neural network trained on the electrocardiogram to identify patients with clinical history of myocardial infarction. We assessed 608 patients at two academic centers with adjudicated history of myocardial infarction. Surface electrocardiograms were used to train a neural network-based model that classifies patients with and without a history of infarction. Endpoints were assessed by clinical record review and accuracy of the model was compared against the manual assessment of pathologic Q waves. The neural network outperformed the accuracy of pathologic Q waves (62%). In training, the model accuracy converged to >98%. Validation was performed by cross-validation (k=5) with validation accuracy 71 ± 5%. Receiver-operator characteristics analysis resulted in a c-statistic of 0.730. Deep learning of a 12-lead ECG can identify features of prior myocardial injury more accurately than clinical Q-wave analysis and may serve as a valuable clinical screening tool.
AtıfScopus3OpenAlex3
İncele - MakaleAçık Erişim2021Scopus SJRQ2Protective Effect of Lutein/Zeaxanthin Isomers in Traumatic Brain Injury in Mice
Gunal, Mehmet Yalcin; Sakul, Ayse Arzu; Caglayan, Ahmet Burak; Erten, Fusun; Kursun, Oznur Ece Durmaz; Kilic, Ertugrul; Sahin, Kazim
Previous studies revealed that oxidative stress and inflammation are the main contributors to secondary injury after traumatic brain injury (TBI). In an earlier study, we reported that lutein/zeaxanthin isomers (L/Zi) exert antioxidative and anti-inflammatory effects by activating the nuclear factor-kappa B (NF-κB) and nuclear factor-erythroid 2-related factor 2 (Nrf2) pathways. However, its precise role and underlying mechanisms were largely unknown after TBI. This study was conducted to investigate the potential mechanism of L/Zi isomers in a TBI model induced by a cold injury model in mice. To investigate the effects of L/Zi, male C57BL/6j mice-induced brain injury using the cold trauma model was allocated into two groups (n = 7): (i) TBI + vehicle group and (ii) TBI + L/Zi group (20 mg/kg BW). Brain samples were collected 24 h later for analyses. L/Zi given immediately after the injury decreased infarct volume and blood–brain barrier (BBB) permeability; L/Zi treatment also significantly reduced proinflammatory cytokines, including interleukin1 beta (IL-1β), interleukin 6 (IL-6), and NF-κB levels and increased growth-associated protein 43 (GAP-43), neural cell adhesion molecule (NCAM), brain-derived neurotrophic factor (BDNF), and Nrf2 levels compared with vehicle control. These data suggest that L/Zi improves mitochondrial function in TBI models, possibly decreasing inflammation and activating the Nrf2 pathway.
AtıfScopus39OpenAlex40
İncele - MakaleAçık Erişim2021Scopus SJRQ1Thermoset powder coating wastes as filler in LDPE – Characterization of mechanical, thermal and morphological properties
Kismet, Yilmaz; Dogan, Akar; Wagner, Manfred H.
In this study, three different electrostatic powder coating wastes of thermoset structure were used as fillers for low-density polyethylene (LDPE). The mechanical, thermal, and morphological properties of these composites materials are reported. The thermoset powder coating wastes were hydrolyzed using water and alcohol, and then 10%, 20%, and 30% by weight of the deactivated wastes were mixed with LDPE, first in a mechanical dry mixer, and subsequently homogenized by melt compounding in an extruder at about 160 °C. Standard tensile test bars and plate-shaped samples were produced from these homogeneous compounds by injection molding. The effects of adding hydrolyzed powder coating wastes on the properties of LDPE were determined by mechanical, thermal, and morphological tests. Tensile strength and perforation threshold of the sample filled with powder coating wastes decreased to some extent compared to un-filled sample. However, an increase in izod impact and bending strengths has been observed. The results of this investigation demonstrate that powder coating wastes with thermoset structure can be used as fillers in LDPE.
AtıfScopus13WoS15OpenAlex16İncele - MakaleAçık Erişim2021Scopus SJRQ1Chemical profiling and biological evaluation of nepeta baytopii extracts and essential oil: An endemic plant from turkey
Zengin, Gokhan; Mahomoodally, Mohamad Fawzi; Aktumsek, Abdurrahman; Jekő, József; Cziáky, Zoltán; Rodrigues, Maria João; Custodio, Luisa; Polat, Rıdvan; Cakilcioglu, Ugur; Ayna, Adnan
Nepeta baytopii is a poorly studied, endemic Nepeta species (Lamiaceae) of Turkey. For the first time, the biological activities (antioxidant, enzyme inhibition, and cytotoxicity properties) of the hexane, ethyl acetate, methanol, water/methanol, and water extracts and essential oil prepared from N. baytopii aerial parts were assessed. Hydro-methanol (41.25 mg gallic acid equivalent (GAE)/g) and water extracts (50.30 mg GAE/g), respectively showed the highest radical scavenging (94.40 and 129.22 mg Trolox equivalent (TE)/g, for 2,2-diphenyl-1-picrylhydrazyl radical and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays) and reducing (229.37 and 129.55 mg TE/g, for ferric-reducing antioxidant power and cupric-reducing antioxidant capacity assays) capacities in vitro. An interestingly high inhibition was observed for ethyl acetate extract against butyrylcholinesterase (10.85 mg galantamine equivalent/g). The methanol extract showed high cytotoxicity (31.7%) against HepG2 cells. Caryophyllene oxide was identified in high concentrations in the essential oil (39.3%). Luteolin and apigenin and their derivatives were identified from the methanol and water extracts. The results obtained from this study highlighted that the abundance of highly bioactive compounds from Nepeta baytopii ensures the multiple biological activities of the tested extracts, and this suggests a potential use in the pharmaceutical and nutraceutical fields, and therefore should be investigated further.
AtıfScopus32OpenAlex32İncele - MakaleAçık Erişim2021Scopus SJRQ2Evaluation of chemical constituents and biological properties of two endemic Verbascum species
Zengin, Gokhan; Mahomoodally, Mohamad Fawzi; Sinan, Kouadio Ibrahime; Sadeer, Nabeelah; Maggi, Filippo; Caprioli, Giovanni; Angeloni, Simone; Mollica, Adriano; Stefanucci, Azzurra; Ak, Gunes
Members from the Verbascum genus are well appraised for their traditional uses against a variety of ailments including anti-inflammatory related disorders. This study thus attempts at validating the biological properties of two underexplored Verbascum members namely Verbascum euphraticum Benth. (V. euphraticum) and Verbascum oocarpum Murb. (V. oocarpum) in terms of their antioxidant and enzymatic inhibitory activities. Concentration of specific bioactive compounds was also established and molecular dynamic analysis were conducted on amassed data. Results showed that total phenolic and total flavonoid contents were higher for the methanolic extract of V. oocarpum compared to the methanolic extract of V. euphraticum. Phytochemical quantification revealed that the extraction solvents influenced the phytochemical composition of the extracts. Derivatives of phenolic acids such as 3-caffeoylquinic acid and 3,5-dicaffeoylquinic acid together with some phenolic acids i.e., gallic, vanillic, caffeic, syringic, p-coumaric and ferulic acid, have been detected in the extracts of both Verbascum species. Methanolic extracts of V. euphraticum and V. oocarpum yielded the highest total content of monitored compounds resulting in 162.758 and 3716.861 μg/g of dried weight extract, respectively. The methanolic extracts of both plants showed highest antioxidant potential while the ethyl acetate and hexane extracts were potent inhibitors of cholinesterase, α-amylase and α-glucosidase. Molecular dynamic results indicated that vanillic acid is able to make strong interactions with copper ions of tyrosinase, resulting into an effective anti-tyrosinase activity. In light of the above, both Verbascum species could be considered for future phytopharmaceutical development.
AtıfScopus36OpenAlex36İncele - MakaleAçık Erişim2021Scopus SJRQ2Exposure to copper and risk assessment for human health via consumption of alcoholic beverages
Ince, Muharrem; Kaplan Ince, Olcay; Onal, Ali
Present study was performed using a Box–Behnken Design (BBD) combined with a response surface methodology (RSM). The ultimate goal of this research was to apply BBD for modeling of copper (Cu2+) ions from alcoholic beverages and evaluate health risk assessment of Cu2+ via consumption of alcoholic beverages. The importance of independent paramaters and their interactions were examined using analysis of variance (ANOVA). Natural clay was investigated to remove Cu2+ ions from some alcoholic beverage samples including beer and wine. X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDS) analysis were used for adsorbent characterization. Same analyzes were applied for Cu2+ loaded clay. In addition, experimental studies showed that Freundlich isotherm was better than Langmuir isotherm. Finally, optimized method was applied to alcoholic beverages. Besides target hazard quotients (THQ), estimated daily intake (EDI) values were calculated, to assess a health risk resulting from these alcoholic beverages regular consumption. The EDI values of Cu (µg/day/person) through consumption of investigated drinks were less than the recommended dietary allowance values. Also, the THQ values of Cu2+ were less than 1. According to estimated target hazard, it can be said no long life health concerns of Cu2+ is associated with the consumption of studied drinks. Obtained results were compared with the data from literature and levels set by regulatory authorities, it can be clearly stated that the consumption of mentioned alcoholic beverages do not pose a toxicological risk.
AtıfScopus14WoS10OpenAlex11İncele - MakaleAçık Erişim2021Scopus SJRQ3On complex Sasakian manifolds
Turgut Vanlı, Aysel; Ünal, İnan; Avcu, Keziban
In this article, we study a class of normal complex contact metric manifold called a complex Sasakian manifolds. This kind of manifolds have a globally defined complex contact form and normal complex contact structure. We define a complex Sasakian manifold by considering the real case and we present general properties. Also, we obtain some useful curvature relations. Finally, we examine flatness conditions for general curvature tensor B.
AtıfScopus3OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ1Evaluation of non-carcinogenic health risks of thallium in grapevine exposed to mine waters of an abandoned mining region in Turkey
Topal, Murat; Arslan Topal, E. Işıl; Öbek, Erdal
In this study, non-carcinogenic health risks of thallium in grapevine exposed to mine waters of an abandoned mining region in Turkey were evaluated. The values of thallium were investigated in leaves, stems, and roots. Translocation factors (TF) and bioaccumulation concentration factors (BCF) were determined. The maximum thallium value in grapevines (root) was 2.34 ± 0.12 mg/kg. Thallium values in grapevine were stem < leaf < root. The bioconcentration value calculated in our study is higher than 1 showing thallium bioaccumulation from the mine water to grapevines. Translocation factor value is calculated as 1.20. The high total estimated daily exposure dose (TED) in grapevines was determined as 1.10E-02 mg/kg day for children. TEDs values in grapevines were observed as male < female < children, respectively. The maximum HQ risk value for male was observed as 1060 for children. The non-carcinogenic risk values were children > female > male. Hazard index values of thallium in grapevines were ingestion < dietary. As a result, hazard and total hazard index values were > 1 for thallium in grapevines. Therefore, there are non-carcinogenic health risks of thallium in grapevine exposed to mine waters of an abandoned mining region.
AtıfScopus3WoS1OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ3Ultrasonic assisted turning of AISI 52100 steel using nanoparticle-MQL method
Aǧar, Salih; Tosun, Nihat
High cutting force and high cutting tool-chip interface temperature occur during machining of high strength materials like AISI 52100 by using conventional turning method and this makes to the difficult machining operation. Besides, in conventional turning (CT) of these materials, which has high abrasion resistance and hardness properties, an additional process such as grinding is required to achieve the desired surface quality. Ultrasonic assisted turning (UAT) method has been widely used in the machining industry in recent years, as it exhibits better surface quality, lower cutting forces, and cutting temperature than the CT method. This paper focused on experimentally and statistically determining the effects of different cutting parameters and cooling conditions (dry and minimum quantity lubrication-MQL) on surface roughness, workpiece surface texture, tangential direction cutting force, and cutting tool-workpiece interface temperature in the machining of AISI 52100 material by using UAT and CT methods. The experimental results revealed that significant improvements determined in the cutting forces and the surface roughness occurred in UAT compared to CT in all the cooling conditions. However, the increasing cutting speeds caused to observe higher interface temperature values in dry turning by the UAT method. Variance Analysis (ANOVA) was carried out to determine the significance grade of independent variables on dependent variables. According to ANOVA results, while the cutting speed is the most important factor on the surface roughness and the cutting zone temperature, and the cooling method is the most important factor on the cutting force. The effects of turning methods on corresponding surface topography, including surface defects, were evaluated. It is determined that in the surface topography analysis, feed marks are the main texture of the workpiece in the CT method while micro-level indentations and protrusions occurred on the workpiece surface in the UAT method.
AtıfScopus14WoS12OpenAlex14İncele - MakaleAçık Erişim2021Scopus SJRQ4Electrochemical Corrosion and Metal Ion Release Protective Efficiency of the Multilayer TaN Coatings on CoCrMo Biomedical Alloy
Aslan, Ali Kemal; Bahçe, Erkan; Güler, Mehmet Sami
CoCrMo alloy is widely used in artificial orthopedic joint applications due to its high mechanical properties. But, high levels of the metal ion release from alloy surfaces cause variable toxic and allergic effects on the patient in vivo use. This case restricts the lifetime of the implant and results in the failure of the artificial joint. In order to enhance the corrosion resistance and to decrease the metal ion release, alloy surface was multilayer-coated by closed field unbalanced magnetron system. The protective efficiency of the coatings was determined by potentiodynamic polarization tests and static immersion tests were performed for 45, 60 and 90 days in the simulated body fluid in order to understand the effect of the coatings on the metal ion release. The metal ion concentrations in the simulated body fluids were determined by using inductively coupled plasma mass spectrometry device. The electrochemical corrosion results showed that the multilayer coatings provided 93 % protective efficiency in terms of corrosion resistance. Multilayer coatings decreased the metal ions release levels significantly, especially Co leaking was decreased approximately 52 times compared to uncoated samples.
AtıfScopus2WoS3OpenAlex1İncele - MakaleAçık Erişim2021Scopus SJRQ1An integrated interval type 2 fuzzy AHP and COPRAS-G methodologies for supplier selection in the era of Industry 4.0
Kayapinar Kaya, Sema; Aycin, Ejder
Supply chain has a very extensive and dynamic structure that incorporates new business models, new customer expectations, market searches and technological developments. With the introduction of Industry 4.0 into supply chain, a rapid and intensive process of digitalization begins to transform every step of supply chain. Supply chain selection is one of the essential decisions in reducing the supply chain cost and improving overall quality of product and services. With the implication of digital technologies and Industry 4.0 on supply chain, the supplier selection process has been significantly changed during the recent years. Companies are willing to need new requirements for their own suppliers in accordance with Industry 4.0 implementations and technologies. This paper aims to identify key criteria to Industry 4.0 technologies and evaluate them to select the right suppliers selection in the era of Industry 4.0. Within the scope of this study attempts to develop an integrated interval type 2 fuzzy AHP and GOPRAS-G methodology to select the appropriate supplier in the face of Industry 4.0 implementations. For this purpose, interval type 2 fuzzy AHP was employed to weight the supplier evaluation criteria and then, Gray COPRAS method has been applied to prioritize suppliers. This paper is to provide practitioners and researchers with insight into how Industry 4.0 strategies influence on supplier selection.
AtıfScopus63WoS51İncele - MakaleAçık Erişim2021Scopus SJRQ2Comparative Toxicity of Alpha and Gamma Iron Oxide Nanoparticles in Rainbow Trout: Histopathology, Hematology, Accumulation, and Oxidative Stress
Gürkan, Mert; Gürkan, Selin Ertürk; Yılmaz, Sevdan; Ateş, Mehmet
In this study, alpha and gamma iron oxide nanoparticles, characterizations, toxic effects after being exposed to rainbow trout (Oncorhynchus mykiss) at 0, 1, 10 and 25 mg/L concentrations for 10 days, and then 10-day recovery period without any nanoparticle exposure were examined for histopathological (kidney, liver and gill), hematological, iron accumulation and potential for oxidative stress (TBARS and GSH). Histopathological damages significant at the exposure of increasing concentrations of both nanoparticles (increase in melanomacrophage aggregations, epithelial tissue deformations, cytoplasmic vacuolizations, fatty changes, necrosis, pyknosis, hyperplasia, hypertrophy, lamellar fusions, capillary dilatations). Gamma nanoparticles were determined to accumulate more than the alpha nanoparticles. The most Fe accumulation was detected in the liver. The findings of oxidative stress parameters showed that both nanoparticles have the potential to generate oxidative stress. It was concluded that the exposure of alpha and gamma nanoparticles at specified concentrations and durations had a toxic effect on rainbow trout and the toxicity of these nanoparticles was similar.
AtıfScopus18WoS12OpenAlex16İncele - MakaleAçık Erişim2021Scopus SJRQ2Electrical investigation on Eu+3- doped copolymer composite system and conventional kinetic analysis
Pıhtılı, Güzin; Biryan, Fatih
Poly(maleic anhydride-co-benzyl methacrylate) copolymer was prepared by using free radical polymerization (FRP) method at 70 °C. The structural characterization of the polymer was accomplished FT-IR, 1H and 13C NMR spectroscopic techniques. P(MA-co-BMA)/ EuCl3 composites were prepared rate of 2%, 5% and 10% (wt/wt). The thermal behavior of pure copolymer was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal decomposition kinetics of poly(MA-co-BMA) carried out from Flynn–Wall–Ozawa method via TG curves for calculated apparent activation energies. According to FWO; the activation energy (Ea) was estimated as; 185.61 kJ/mol. Dielectric and electrical properties of copolymer/composite systems were investigated against frequency (range from 100 Hz to 20 kHz) at room temperature by using an impedance analyzer. The effect of EuCl3 concentration on dielectric constant, dielectric loss factors, ac conductivity, susceptance (B) and impedance (Z) was investigated. A remarkable increase was observed in dielectric and AC electrical properties were observed with the addition of Eu+3 to the polymer matrix. The B and Z parameters of poly(MA-co-BMA) and composites were investigated depending on frequency at room temperature based on the alternating current (AC).
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2021Influence of particle size, additive ratio and chemical structure of zinc borate on mechanical properties of poly(vinyl chloride)
İpek, Yeliz
Zinc borate (ZB) is a flame retardant and smoke supressant compound of boron. It is widely used to achieve flame resistant polymer composites. Poly(Vinyl Chloride) (PVC) is one of the commercially important polymers that is mostly used for cable insulating, windows, doors, pipes, floorings and toys etc.. On the other hand, PVC releases toxic gases during fire as decomposition products. Zinc borate addition is thought to be a solution for this problem. However, this solution leads a new problem. Zinc borate effects the mechanical properties of the PVC. In the present study, to optimize the contribution of zinc borate, with different formulations (2ZnO·3B2 O3·3.5H2 O and 4ZnO·B2 O3·H2 O), with different additive ratios (1% and 5% by weight) and different particle sizes (nano-sized and micro-sized) were added to the PVC structure and the mechanical and thermomechanical properties of each composite were investigated. Mechanical properties of composites were determined by tensile test, impact test, hardness test while thermomechanical behaviours were detected with dynamic mechanical analysis (DMA). In the perspective of mechanical strength of PVC-ZB composite, additive ratio of ZB was more effective than particle size and chemical formulation of ZB. The additive ratio more than 5% by weight can negatively affect the mechanical strength and quality of the PVC-ZB composite.
AtıfScopus2OpenAlex2
İncele - MakaleAçık Erişim2021Scopus SJRQ2Hospital Preparedness Assessment against COVID-19 Pandemic: A Case Study in Turkish Tertiary Healthcare Services
Gul, Muhammet; Yucesan, Melih
Hospitals play a critical role in providing essential health services to people in the healthcare system. Healthcare systems around the world have faced some issues in responding to patients with various disease severity levels. Nowadays, the world as a whole is combating a pandemic called COVID-19. This pandemic causes an increase in the disease spread with fluctuated patient demand that may affect the hospitals' capacity and overall functioning and risks rising based on hospital site, medical staff, patient, and healthcare process. To deal with the challenges of the COVID-19 pandemic, hospitals must have completed their preparations before these events occur. Therefore, this study proposes an integrated approach based on the decision-making concept with interval-valued spherical fuzzy sets (IVSFSs) to the hospital preparedness assessment problem. A technique for order preference by similarity to ideal solution (TOPSIS) extended with IVSFSs is used to rank hospitals from Turkish tertiary healthcare services. A checklist reported by the World Health Organization (WHO) is adapted to conform to Turkey's COVID-19 pandemic management. Ninety-nine subcomponents of the adapted checklist under ten components are weighted by interval-valued spherical weighted arithmetic mean (IVSWAM) operator. The hospitals in the problem are then ranked concerning these weighted subcomponents. With the proposed approach, a COVID-19 pandemic preparedness index is determined for the observed hospitals. In addition, a separate index based on each main component (component-based ranking) is determined. These indexes are vital indicators in determining in which aspects hospitals are ready and in what aspects hospitals are not prepared for pandemics. The proposed approach can be adaptable and applied by national policymakers in assessing all hospitals of the country against the COVID-19 pandemic.
AtıfScopus45WoS33OpenAlex44İncele - MakaleAçık Erişim2021Scopus SJRQ1Carbon and water balance of an afforested shallow drained peatland in Iceland
Bjarnadottir, Brynhildur; Aslan Sungur, Guler; Sigurdsson, Bjarni D.; Kjartansson, Bjarki T.; Oskarsson, Hlynur; Oddsdottir, Edda S.; Gunnarsdottir, Gunnhildur E.; Black, Andrew
Drainage of peatlands increases the depth of the oxic peat layer and can turn them into a carbon (C) source to the atmosphere. Afforestation of drained peatlands could help to reverse this process since the trees may enhance C sequestration. We followed the C and water dynamics of an afforested drained peatland in S-Iceland during a 2 year period, during which the Black Cottonwood (Populus balsamifera ssp. trichocarpa) plantation was 23–25 year old. Net ecosystem exchange (NEE) of carbon dioxide (CO2) was measured with the eddy covariance method and C pools of trees and ground vegetation were measured using the stock change method. Lateral losses of dissolved and particulated organic C (DOC, POC) were estimated from weekly water-runoff samples. Unexpectedly, the afforested drained peatland was a strong sink of carbon during the two years, with an average NEE value of 714 g C m−2 yr−1. Only 0.5% of the total NEE was lost through lateral DOC and POC transport, leaving 710 g C m−2 yr−1 as the total net ecosystem production (NEP). Ca. 91% of the observed NEP could be explained by the annual biomass increment of the Black Cottonwood trees and 1.3% by the ground vegetation. This means that the remaining 7.5% of the total NEP most likely accumulated in peat soil and litter, contributing to the soil C stocks. The dormant-season CO2 emissions were unexpectedly low, which was explained by a high groundwater level at this drained site outside the ca. 5 months of the active growing season. On average, 66% of the annual measured precipitation was estimated to have evaporated back to the atmosphere. This left 416 mm for potential runoff, which was somewhat lower value than the measured runoff (662 mm). These results indicate that during the age span of ca. 20–25 years, afforestation was a valid method to reverse the expected negative C-balance of this drained grassland pasture in Iceland. Although the site is currently a soil C sink, simulation studies with process models are needed to test whether such sites could remain C sinks when managed for forestry over several tree-stand rotations.
AtıfScopus18OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ1Investigation on the properties of new palm-oil-based polyurethane modified bitumen
Vural Kök, Baha; Aydoğmuş, Ercan; Yilmaz, Mehmet; Akpolat, Mustafa
Polyurethane-derived polymer synthesized by the reaction of 4.4′-diphenylmethane diisocyanate (MDI) with the new modified palm-oil-based polyol was used as an alternative additive to thermoplastic-elastomers, such as styrene–butadienestyrene (SBS), the most commonly used additive. The study aimed to investigate the effect of polyurethane (PU) modification on the rheological and chemical structure of base bitumen. The softening point, rotational viscosity, dynamic shear rheometer (DSR), multi-stress creep recovery (MSCR), bending beam rheometer (BBR), and Fourier transform infrared (FTIR) tests were conducted on the binders. The effects of curing time and temperature, isocyanate/hydroxyl (NCO/OH) molar ratio, and PU content were examined and the best modification conditions were determined. It was found that 24 h curing conditions at 85 °C were sufficient for the formation of PU bonds and these processes increased the rutting parameter of the binder by 256% compared to 1 h curing. At 50 °C and a frequency of 5 Hz, the binder with a 4:1 NCO/OH ratio had 63% more complex modulus than the binder with a 10:1 NCO/OH ratio. The 7 wt% PU modified binder had the same performance level as 4% SBS modification and 10 wt% PU modified binder was one degree higher. Moreover, above 60 °C, all the PU modified binders gave lower phase angles compared to the 4% SBS modified binder. 7 wt% PU modified binder showed similar elastic properties against cracks at low temperatures compared to the 4% SBS modified binder. The use of palm oil in the synthesis of PU presents an environmentally friendly and cost-effective solution compared to the use of petrochemical derivatives.
AtıfScopus56WoS53OpenAlex60İncele - MakaleAçık Erişim2021Scopus SJRQ1A Method to Determine the Most Suitable Initial Conditions of Chaotic Map in Statistical Randomness Applications
Acikkapi, Mehmet Sahin; Ozkaynak, Fatih
The processes and systems in the real world actually contain order and symmetry. Understanding these order and symmetrical behavior has been a common effort of scientists. Chaos theory has been an interesting topic to understand these order and symmetrical behavior. One of the most important reasons for this interest is the rich dynamics of chaotic systems. A remarkable application of these systems is statistical randomness. Especially in random number generator designs based on discrete time chaotic systems, an important design parameter affecting the success of the generator (statistical randomness properties) is the initial conditions of chaotic maps. Obtaining different initial conditions that will meet the statistical requirements is important in terms of generating different random number sequences. In order to determine the initial conditions, an algorithm that updates the initial conditions depending on the number of successful statistical tests is proposed. Although the proposed design approach is similar to a back propagation neural network, it has a unique design approach. The NIST SP 800-22 test suite has been used to analyze the statistical properties of the proposed generator. It is known that the NIST SP 800-22 test suite is a hypothesis test. Therefore, in order to show the success of the proposed method in the best way, various additional analysis studies have been carried out proving that the generator outputs have a uniform distribution. Using the proposed method, six different initial conditions have been determined that provide statistical random properties for the discrete-time chaotic systems known as logistic map and tent map. 1,000,000 bits have been generated using the obtained initial conditions. These bit values are then converted to decimal values between 0-15. It is observed that the obtained numbers have a uniform distribution. These outputs are thought to be applicable in many areas such as games, simulation, modeling, determination of optimization parameters and cryptology. It is shown in a practical application for cryptographic substitution-box designs to examine the success of the outputs.
AtıfScopus34WoS23OpenAlex29İncele - MakaleAçık Erişim2021Scopus SJRQ2Lycopene ameliorates propionic acid-induced autism spectrum disorders by inhibiting inflammation and oxidative stress in rats
Erten, Fusun
This study was conducted to study lycopene efficacy in brain-behavior, pro-inflammatory and apoptotic markers, and antioxidant levels in a rodent model. Rats were administered with propionic acid (PPA) (500 mg/kg BW) to induce autism-like disorders, then treated with different lycopene (L) concentrations (5, 10, 20 mg kg−1 day−1) for 35 days. The groups were: (i);control, (ii);PPA, (iii);PPA + L5, (iv);PPA + L10, and (v);PPA + L20. In this study, serum and brain malondialdehyde (MDA) levels decreased with lycopene supplements compared to the PPA group, similarly to the brain levels of inflammatory factors (IL-1α, IL-8, NF-κB, TNF-α; p <.05). Besides, brain levels of anti-apoptotic Bcl-2 decreased, whereas pro-apoptotic Bax, antioxidant Nrf2, and HO-1 levels in brain increased compared with PPA (p <.05). This study showed that lycopene might have therapeutic value to improve the dysfunctions in learning and memory in a dose-dependent way, along with the antioxidant, anti-inflammatory, and antiapoptotic molecular responses in a rat model of ASD-like disorders. Practical applications: This study suggested that lycopene can reduce propionic acid (PPA)-induced learning and memory impairment and oxidative damage by participating in multiple biological activities such as antioxidant, and anti-inflammatory effects. Lycopene protects serum and brain tissues against PPA induced oxidative damage in rats. These effects may be realized through up-regulation of the brain Nrf2/HO-1 pathway and down-regulation of the IL-1α, IL-8, TNF-α, and NF-κB levels. Lycopene may also contribute to memory and learning function, apoptotic/antiapoptotic modulation, and antioxidant and possible therapeutic efficacy in PPA-induced- Autism spectrum disorder cases.
AtıfScopus26WoS19OpenAlex26İncele - MakaleAçık Erişim2021Scopus SJRQ2In vitro biological activity of Salvia fruticosa Mill. infusion against amyloid β-peptide-induced toxicity and inhibition of GSK-3β, CK-1δ, and BACE-1 enzymes relevant to Alzheimer's disease
Gürbüz, Perihan; Dokumacı, Alim Hüseyin; Gündüz, Miyase Gözde; Perez, Concepcion; Göger, Fatih; Paksoy, Mehmet Yavuz; Yerer, Mükerrem Betül; Ömür Demirezer, L.
Salvia species have been traditionally used to improve cognition and have been proved to be a potential natural treatment for Alzheimer's disease. Salvia fruticosa Mill. (Turkish sage or Greek sage) demonstrated to have anticholinergic effects in vitro. The aim of this study was to understand the mechanism underlying the neuroprotective effects of S. fruticosa infusion and its representative compound rosmarinic acid, which was detected by LC-DAD-ESI-MS/MS. The protective effects of the S. fruticosa infusion (SFINF) and its major substance rosmarinic acid (RA) on amyloid beta 1–42 -induced cytotoxicity on SH-SY5Y cells together with p-GSK-3β activation were investigated. Their in vitro inhibitory effects against glycogen synthase kinase 3β, β-secretase, and casein kinase 1δ enzymes were also evaluated. The results showed that treatment with the all tested concentrations, SFINF significantly decreased Aβ 1–42-induced cytotoxicity and exhibited promising in vitro glycogen synthase kinase 3β inhibitory activity below 10 µg/mL (IC50 6.52 ± 1.14 µg/mL), in addition to β-secretase inhibition (IC50 86 ± 2.9 µg/mL) and casein kinase 1δ inhibition (IC50 121.57 ± 4.00). The SFINF (100 µg/mL and 250 µg/mL) also activated the expression of p-GSK-3β in amyloid beta 1–42 treated SH-SY5Y cells. The outcomes of this study demonstrated that the S. fruticosa infusion possessed activity to prevent amyloid beta 1–42 -induced neurotoxicity and provided proof that its mechanism may involve regulation of p-GSK-3β protein.
AtıfScopus18OpenAlex17İncele