Browsing by Author "Nas, Mehmet Salih"

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Ecotoxicological Effects of Bimetallic Pdni/Mwcnt and Pdcu/Mwcnt Nanoparticles Onto Dna Damage and Oxidative Stress in Earthworms
(Springernature, 2022) Kokturk, Mine; Altindag, Fikret; Nas, Mehmet Salih; Calimli, Mehmet Harbi
Bimetallic nanoparticles are synthesized using two different metal elements and used recently in many fields. However, limited studies related to the ecotoxic effects of nanoparticles available in the literature. The purpose of this study is to synthesize and characterize bimetallic PdCu/MWCNT and PdNi/MWCNT NPs and investigate their ecotoxic effects on earthworms. For this purpose, we injected approximately 20 mu L of various concentrations of bimetallic PdCu/MWCNT and PdNi/MWCNT NPs (1, 10, 100, 1000, and 2000 mg/L) into the coelomic space of earthworms. We evaluated survival rate, malformations, reactive oxygen species (ROS) level, 8-OHdG content, and histopathological changes in earthworms at the 48th hour after exposure. PdCu/MWCNT and PdNi/MWCNT NPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) pattern, and Raman-scattering spectroscopy. Toxicological examinations showed that PdCu/MWCNT NPs reduced the survival rate of earthworms (2000 mg/L, 84%) and caused various malformations (various lesions, thinning, swelling, and rupture), but nonsignificant effects of survival rate and malformations were observed in earthworms using PdNi/MWCNT NPs. The histopathological examinations of earthworm tissues exposed with PdNi/MWCNT determined that tissues in all treatment groups had a normal histological appearance. However, at a concentration of 2000 mg/L of PdCu/MWCNT NPs, atrophy in the longitudinal muscle layer and less degenerative cells in the epidermis layer were observed in earthworm tissues. It was determined that PdNi/MWCNT and PdCu/MWCNT NPs caused significant increases in ROS levels and 8-OHdG activity in earthworm tissues after 48 h. Finally, our results demonstrated that the toxicity of PdNi/MWCNT NPs was detected to be lower than PdCu/MWCNT NPs. However, both nanoparticles may pose a toxicological risk at high concentrations (1000 and 2000 mg/L). These findings will provide valuable information to studies on the use of PdNi/MWCNT NPs in wastewater treatment systems, industrial and medical fields, which have been determined to have less ecotoxicological risk.
Exploring Thermodynamics and Kinetic Parameters of Immobilized Catalase Enzyme Via Adsorption on Krill Clay
(desalination Publ, 2017) Nas, Mehmet Salih; Gur, Aycan; Gur, Tugba; Yonten, Vahap
The thermodynamic parameters and immobilization kinetics of catalase enzyme via adsorption onto krill clay were performed in aqueous solution in batch system. The adsorbent was characterized by X-ray fluorescence, scanning electron microscope and Brunauer-Emmett-Teller N-2 adsorption measurements. The effect of some parameters to the adsorption process such as contact time, stirring speed, initial enzyme concentration, initial ionic strength, temperature and pH were analyzed. Maximum adsorption capacity (q(m)) showed a great dependence on pH and initial enzyme concentration. It was found at pH 5.5, and initial enzyme concentration, 0.0075 g L-1 values. Pseudo-first-order, pseudo-second-order and intraparticle diffusion were used to fit the kinetics data on kinetic models. Furthermore, thermodynamic activation parameters such as enthalpy, entropy, Gibbs free energy and activation energy (Delta H degrees, Delta S degrees, Delta G degrees and E-a) which reveal that catalase enzyme adsorption occur spontaneously and in endothermic nature were determined. The obtained results confirmed that the applicability of krill clay is an efficient immobilizing supporter for catalase enzyme and krill clay material can be used as a very effective adsorbent in immobilization of this enzyme from aqueous solutions.
Has Pdcu@go Effect on Oxidant/Antioxidant Balance? Using Zebrafish Embryos and Larvae as a Model
(Elsevier Ireland Ltd, 2023) Ucar, Arzu; Yeltekin, Asli Cilingir; Kokturk, Mine; Calimli, Mehmet Harbi; Nas, Mehmet Salih; Parlak, Veysel; Atamanalp, Muhammed
Industrial products containing PdCu@GO can gain access to the aquaculture environment, causing dangerous effects on living biota. In this study, the developmental toxicity of zebrafish treated with different concentrations (50, 100, 250, 500 and 1000 mu g/L) of PdCu@GO was investigated. The findings showed that PdCu@GO administration decreased the hatchability and survival rate, caused dose-dependent cardiac malformation. Reactive oxygen species (ROS) and apoptosis were also inhibited in a dose-dependent manner, with acetylcho-linesterase (AChE) activity affected by nano-Pd exposure. As evidence for oxidative stress, malondialdehyde (MDA) level increased and superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx) activities and glutathione (GSH) level decreased due to the increase in PdCu@GO concentration. Our research, it was determined that the oxidative stress stimulated by the increase in the concentration of PdCu@GO in zebrafish caused apoptosis (Caspase-3) and DNA damage (8-OHdG). Stimulation of ROS, inflammatory cytokines, tumor Necrosis Factor Alfa (TNF-alpha) and interleukin - 6 (IL-6), which act as signaling molecules to trigger proin-flammatory cytokine production, induced zebrafish immunotoxicity. However, it was determined that the in-crease of ROS induced teratogenicity through the induction of nuclear factor erythroid 2 level (Nrf-2), NF-icB and apoptotic signaling pathways triggered by oxidative stress. Taken together with the research findings, the study contributed to a comprehensive assessment of the toxicological profile of PdCu@GO by investigating the effects on zebrafish embryonic development and potential molecular mechanisms.
In Situ Preparation of Tio2/F-mwcnt Catalyst Using Pluronic F127 Assisted Sol-Gel Process for Sonocatalytic Degradation of Methylene Blue
(Academic Press inc Elsevier Science, 2023) Yildiz, Adnan; Yesilbas, Omer Faruk; Nas, Mehmet Salih; Calimli, Mehmet Harbi; Bayat, Ramazan; Sen, Fatih
In this study, titanium dioxide-Pluronics @F127/functionalized-multi walled carbon nanotubes (TiO2-F127f-/ MWCNT) nanocatalysts were prepared, characterized, and used in methylene blue (MB) degradation under ul-trasonic conditions. The characterization studies were performed using TEM, SEM, and XRD analyses to reveal the morphological and chemical properties of TiO2-F127/MWCNT nanocatalysts. To detect the optimum pa-rameters for MB degradation using TiO2-F127/f-MWCNT nanocatalysts, several experimental parameters were conducted at various conditions such as different temperatures, pH, catalyst amount, hydrogen peroxide (H2O2) concentration, and various reaction contents. Transmission electron microscopy (TEM) analyses showed that TiO2-F127/f-MWCNT nanocatalysts consisted of a homogenous structure and have a 12.23 nm particle size. The crystalline particle size of TiO2-F127/MWCNT nanocatalysts was found to be 13.31 nm. Scanning electron microscope (SEM) analyses revealed the surface structure of TiO2-F127/f-MWCNT nanocatalysts turned to be modified after TiO2 loaded on MWCNT. Under the optimum conditions; pH: 4, MB concentration: 25 mg/L, H2O2 concentration: 30 mol/L, reaction time: and catalyst dose: 24 mg/L, chemical oxygen demand (COD) removal efficiency reached a maximum of 92%. To detect the radical effectiveness, three scavenger solvents were tested. Reuse experiments revealed that TiO2-F127/f-MWCNT nanocatalysts retained 84.2% catalytical activity after 5 cycles. Gas chromatography-mass spectrometry (GC-MS) was successfully used to identify the generated in-termediates. Based on the experimental results, it has been suggested that center dot OH radicals are the main active species responsible for the degradation reaction in the presence of the TiO2-F127/f-MWCNT nanocatalysts.
Investigation of Anticancer Activity of Globularia Trichosanthafisch. & C.a.mey (globulariaceae)
(2023) Can, Abdurrahman; Özgökçe, Fevzi; Nas, Mehmet Salih
Mide kanseri, Van ili ve çevresinde en çok karşılaşılan kanser tiplerinden biridir. Bölgede mide kanserine karşı pek çok bitki türü kullanılmaktadır. Bu bitkiler arasında en sık kullanılan bitki türü Globulariaceae familyasına ait Globularia trichosantha Fisch. & C. A. Mey.'dir. Globularia L. cinsine ait 11 taksondan 5'i ülkemiz için endemiktir. Globularia trichosantha ilişkili herhangi bir kanser ve tıbbi çalışmalarına rastlanmamıştır. Çalışmanın esas amacı, halkın doğadan elde ettiği ve kullanımı ile fayda sağladığı bitki türünün tespit edilerek bunu laboratuvar ortamında potansiyel tıbbi hammadde elde edilmesidir. Çalışmada G. trichosantha türüne ait herbaryum materyalleri arazide toplanmış ve bunlara ait video ve fotoğraf kayıtları alınmıştır. Bitki örneklerinin teşhisleri yapmak için Herbaryum materyali haline getirilmiş ve sonra VANF herbaryumunda saklanmıştır. Mide kanserine karşı halkın tükettiği bitkisel drogların; kullanım süreleri, kullanım şekilleri ve dozu belirlenmiştir. Yetişme habitatlarında toplanan G. trichosantha'nın kök ekstraktının antikanser aktivitesi araştırılmıştır. Araştırma in vitro ortamda, HGC-27, A549/BEAS-2B, DU-145/PNT1-A, HUVEC, CaCO-2, MCF-7, T98-G hücre hatlarında canlılık testi yapılmıştır. İlk etapta A549/BEAS-2B, DU-145/PNT1-A hatlarındaki canlılık testi sonuçları birbirine yakın çıktığından diğer hücre hatlarında zaman ve doza bağımlı değişikliğe gidilerek deneyler tekrarlanmıştır. 15.63 μg/ml, 31.25 μg/ml, 62.50 μg/ml, 125.00 μg/ml, 250.00 μg/ml ve 500.00 μg/ml dozlarında 24 ve 48 saatlik canlılık testleri sonucunda başta HGC-27 olmak üzere belirgin düzeyde hücre ölümlerinin gerçekleştiği görülmüştür. Daha sonra bitkinin içerik analizi LC/MS kullanılarak yapılmış ve analizde yüksek miktarda trans-sinamik asit, protokateşik asit, kafeik asit, kumarik asit, vanilik asit ve sirinjik asit varlığı tespit edilmiştir. Elde edilen sonuçlar ışığında öncelikle Moleküler Biyoloji ve Genetik olmak üzere Eczacılık ve Tıp gibi pek çok farklı bilim dalı için de temel teşkil edecektir. Sonuçta, G. trichosantha'nın ihtiva ettiği etken maddeler belirlenmiştir. Başta eczacılık sektörü olmak üzere mide kanserine karşı ilaç potansiyeli olan etken maddelerin elde edilmesi amaçlanmıştır.
Investigation of Dissolution Kinetics of Tincal Mineral in Ammonium Acetate Solution in High Solid / Liquid Ratios
(2019) Yıldız, Adnan; Nas, Mehmet Salih
The chemical formula of tincal mineral used in this study is Na20-2B203-10H20. The tincalore, one of the important boron minerals, is extracted around Eskişehir in Turkey. Herein, weinvestigated the kinetics of dissolution in different parameters such as concentration, particle size, solid/ liquid ratio, mixing speed and reaction temperature in the ammonium acetate solution of tincal mineral.As a result, boric acid production obtained by dissolution of tincal mineral in amunium acetate solutionincreased with temperature increase. However, in the dissolution process, boric acid production wasfound to be reduced by the increase in particle size and solid-liquid ratio.
May Pdcu@f-Mwcnt Nps Be an Ecotoxicologic Risk
(Wiley, 2023) Alak, Gonca; Yeltekin, Asli Cilingir; Kokturk, Mine; Nas, Mehmet Salih; Parlak, Veysel; Calimli, Mehmet Harbi; Atamanalp, Muhammed
The mechanisms of various metal nanoparticles (NPs) are still a matter of debate in aquatic toxicology. In order to close this gap, the number of studies on this subject is increasing. The aims of this study are to explore the interactions of PdCu@f-MWCNT NPs with zebrafish and get to know if it has an ecotoxicological risk. In this study, we synthesized, characterized PdCu@f-MWCNT NPs, and investigated its ecotoxicological effects. The chemical and morphological structures of PdCu@f-MWCNT nanomaterials were elucidated with advanced analysis techniques such as scanning electron microscope (SEM), X-ray spectrophotometer (EDX), transmission electron microscope (TEM), and X-ray diffraction (XRD) analyses. The ecotoxicological risks were investigated by conducting biochemical analyses and malformation defects in zebrafish. The results were obtained using multiple marker applications including oxidative stress parameters, proinflammatory cytokine expressions, DNA damage, and apoptosis markers. The obtained findings showed embryonic development, survival rate, and incidence of malformation increasing in parallel with the dose increase in zebrafish exposed to PdCu@f-MWCNT NPs at 10-1000 mu g/L levels. Despite the observed decreases in antioxidant enzyme activities, GSH level, AChE activity, and NRF-2 level, inductions in malondialdehyde (MDA) level, IL-6, TNF-alpha, NF-kB, DNA damage, and apoptosis levels were observed with increasing dose. Considering these findings, it has been determined that there are toxic effects in zebrafish at all levels above the concentration that we examine as a safe dose (10 mu g/L). The effects of all studied concentrations of this NP above the safe dosage, especially on oxidative stress, malformation, and immune system, were found to be quite significant. The more widespread use of nanotechnology in the future will mean more contact of aquatic organisms with NPs. As a result, it is clearly seen that these organisms, which form the important link of the food chain, and the aquatic environment are living at risk conditions.
Pdruo2/Pvp Nanomaterial as a Highly Selective, Stable, and Applicable Potentiometric Sensor for the Detection of Cr3+
(Springer Wien, 2024) Cevik, Kenan; Yildiz, Ilyas; Yildiz, Adnan; Nas, Mehmet Salih; Alma, Mehmet Hakki; Calimli, Mehmet Harbi
PdRuO2/PVP nanomaterial was synthesized using a straightforward method and characterized using advanced analytical methods such as TEM, XRD, XPS, elemental mapping and SEM. The synthesized PdRuO2/PVP nanomaterial was used as an ionophore in potentiometric sensor electrodes and successfully adapted to Cr3+ ion detection in a large number of aqueous samples. Several experimental parameters of the PdRuO2/PVP sensor such as potentiometric behavior, selectivity, repeatability, response time, pH, titration, and recovery in real samples were investigated. Potentiometric behavioral characteristics were performed in the concentration range 1 x 10(-6)-1.0 x 10(-1) M. The repeated experiments performed six times showed that there was no deviation in the measurements. The limit of detection of the PdRuO2/PVP potentiometric sensor was very low with a value of 8.6 x 10(-8) M. The potentiometric measurements showed that the synthesized PdRuO2/PVP ionophore was highly effective in detecting Cr3+ in a wide pH range of 2.0-8.0 and was found to have a shelf life of over 1 year. As a result, the synthesized PdRuO2/PVP electrode material was found to be highly selective, stable, and applicable for Cr3+ detection.
Synthesis, Characterization, and Utilization of Niceo2@f-mwcnt/Eda Nanoparticles as Electrode Materials for Supercapacitor Application
(Pergamon-elsevier Science Ltd, 2023) Yildiz, Adnan; Demirel, Serkan; Nas, Mehmet Salih; Calimli, Mehmet Harbi
Metal oxide and carbon nanotube-based materials are widely preferred in supercapacitor and electrochemical sensor applications due to their interesting physicochemical structure. In this paper, we report the synthesis, characterization, and utilization of NiCeO2@f-MWCNT/EDA nanoparticles as electrode materials for supercapacitor applications. The characterization studies of NiCeO2@f-MWCNT/EDA nanomaterials were performed using X-ray diffraction (XRD), Transmission electron microscope (TEM), and Raman spectroscopy apparatus. The characterization methods revealed a good distribution of NiCeO2 on f-MWCNT/EDA and formed a new structure of NiCeO2@f-MWCNT/EDA nanoparticles. Electrochemical studies of NiCeO2@f-MWCNT/EDA nanoparticles showed a significant specific capacitance of between 2385 and 603 Fg  1 with good cyclic stability of 1000 cycles with capacity retention between 42% and 1.4% at 10 mV/s scan rate. The obtained results reveal that the prepared NiCeO2@f-MWCNT/EDA nanoparticles are promising electrode materials for supercapacitor devices.
Textile Dyes Maxilon Blue 5g and Reactive Blue 203 Induce Acute Toxicity and Dna Damage During Embryonic Development of Danio Rerio
(Elsevier Science inc, 2021) Kokturk, Mine; Altindag, Fikret; Ozhan, Gunes; Calimli, Mehmet Harbi; Nas, Mehmet Salih
Common textile dyes used in various industrial sectors are organic compounds and considered for the aquatic environment as pollutants. The textile dye industry is one of the main sectors that have serious impacts on the environment due to a large amount of wastewater released into the ecosystem. Maxilon blue 5G (MB-5G) and Reactive Blue 203 (RB-203) are widely used textile dyes. However, their potential toxicity on living organisms remains to be elucidated. Here, we investigate the acute toxicity and genotoxicity of MB-5G and RB-203 dyes using the zebrafish embryos/larvae. Embryos treated with each dye for 96 h revealed LC50 values of acute toxicity as 166.04 mg L-1 and 278.32 mg L-1 for MB-5G and RB 203, respectively. When exposed to MB-5G and RB-203 at different concentrations (1, 10, and 100 mg L-1) for 96 h, the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, significantly increased in brain tissues as compared to control. MB-5G and RB-203 resulted in common developmental abnormalities including tail malformation, microphthalmia, pericardial edema, curved body axis, and yolk sac/pericardial edemas. Moreover, at its highest dose (100 mg L-1), RB-203 caused premature hatching after 48 h, while MG-5G did not. Our results collectively reveal that the textile dyes MB-5G and RB-203 cause genotoxicity and teratogenicity during embryonic and larval development of zebrafish. Thus, it is necessary to eliminate these compounds from wastewater or reduce their concentrations to safe levels before discharging the textile industry wastewater into the environment.
Yüksek Katı Sıvı Oranlarındaki Tinkalin Amonyum Asetat Çözeltilerinde Çözünme Kinetiği
(2010) Nas, Mehmet Salih; Yıldız, Adnan; Gür, Aycan
Tinkal,sodyum tetra borat, Na2O-2B2O3-.10H2O formülüne sahip ve Eskişehir-Türkiye'de çokça bulunan bir cevherdir.Bu çalışmada tinkalin amonyum asetat çözeltilerindeki çözünme kinetiği bir dizi reaktör kullanılarak incelendi.Çözünme kinetiği için,tanecik büyüklüğü,çözelti konsantrasyonu,katı/sıvı oranı,karıştırma hızı ve reaksiyon sıcaklığının etkileri araştırıldı. çözünme hızının,azalan tanecik boyutu, azalan katı/sıvı oranı, artan reaksiyon sıcaklığı ve artan asit konsantrasyonu ile arttığı ve karıştırma hızından etkilenmediği bulundu Ayrıca kinetik çalışmalarında çözünme hızı homojen ve heterojen reaksiyon modellerine göre incelendi ve reaksiyon kinetiğinin kimyasal reaksiyon kontrollü modele uyduğu ve reaksiyon hızının aşağıdaki gibi gösterilebileceği tespit edildi. 1-(1-x)1/3 = kt Burada t:reaksiyon süresi,k:hız sabiti ve x dönüşüm kesrini göstermektedir. Anahtar kelimeler: Bor minareleri,Tinkal,Amonyum Asetat,Çözünme,Borik Asit