Bilim ve Teknoloji Uygulama ve Araştırma Merkezi Koleksiyonu

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https://hdl.handle.net/11468/10478

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Toxic effects of commercial grade indoxacarb and endosulfan on Gammarus kischineffensis (Schellenberg, 1937) (Crustacea: Amphipoda)
(Elsevier Ltd., 2024) Uğurlu, Pelin; Satar, Elif İpek; Ünlü, Erhan
This study was designed to investigate the toxic effects of two frequently used commercial insecticides containing endosulfan and indoxacarb on a freshwater amphipod Gammarus kischineffensis. In this context, the 24, 48, 72 and 96 h LC50 values of these pesticides were determined for G. kischineffensis. Then the histopathological effects of these pesticides on the gill tissues of this species were evaluated. At the end of the study, the 96 h LC50 values of commercial-grade endosulfan and indoxacarb for G. kischineffensis were determined as 1.861 μg L−1 and 20.212 mg L−1, respectively. Histopathologically, the most common histopathological alterations in individuals exposed to sublethal concentrations of commercial-grade endosulfan and indoxacarb were pillar cell hypertrophy resulting in atrophy of the hemocoelic space and hemocytic infiltration. Considering these results, it can be said that commercial-grade endosulfan is extremely and indoxacarb is slightly toxic to G. kischineffensis.
The nanostructure based SnS chalcogenide semiconductor: A detailed investigation of physical and electrical properties
(Budapest University of Technology and Economics, 2024) Benhaliliba, Mostefa; Ayeshamariam, Abbas; Ocak, Yusuf Selim
In this research, we fabricate SnS films using a low-cost spray pyrolysis technique. Several parameters such as grain size, textural coefficient, Sn concentration, root mean square (RMS), optical band gap, Urbach and dispersion energy are determined by the mean of X-ray diffraction pattern, UV-Vis measurements, surface morphology observation by scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), selective area electron diffraction (SAED) and atomic force microscopy (AFM). Furthermore, SnS thin films exhibit a polycrystalline structure having a low grain size of 6.1 nm along principal (111) orientation. The optical band gap is around 1.9 eV and Urbach energy is of 740 meV. The dielectric parameters of chalcogenide SnS thin film are varying with photon energy within ultraviolet-visible-infrared (Uv-Vis-IR) bands. Besides, the single oscillator E0 and Ed energies are found to be 2.03 and 3.28 eV, respectively, using the Wemple and DiDomenico (WDD) model. Electrical measurements of SnS thin films deposited onto Indium Tin Oxide (ITO) substrate are accomplished and current-voltage (I–V) characteristics of SnO2 / SnS/ITO, are shaped in dark and room temperature conditions. Photovoltaic parameters like open circuit voltage (Voc), short circuit current (Isc), fill factor (FF) and power conversion efficiency (η) values are determined and SnO2 / SnS/ITO junction records the highest values.
The inventive manufacturing and characterization of Au/BG/p-Si/Al devices for solar cell applications
(Springer Science and Business Media Deutschland GmbH, 2024) Benhaliliba, Mostefa; Ocak, Yusuf Selim
Novel dye brilliant green (BG) based devices are fabricated using a low–cost spin coating process on a p–type silicon substrate. The front gold contact is deposited onto the BG film at a high vacuum. The current–voltage measurements in the dark and under various light intensities at room temperature are performed. Experimental data are exploited, and electrical parameters are extracted to describe a non–ideal diode behavior of the BG–based device. The Cheung and Norde approximations and thermionic emission theory are utilized to extract the suitable electrical parameters, including ideality factor (n), barrier height (Φb), series resistance (RS), open-circuit voltage (VOC), short circuit current (ISC), and interface state density (Dit). The capacitance–voltage (C–V) and conductance–voltage (G–V) characteristics of Au/BG/p–Si/Alheterostructure are described in the dark and room temperature. Furthermore, the influence of the resistance series and the interface states on the operation of the diodes in the dark and illumination modes is also emphasized.
Green synthesis of Ag nanoparticles from Verbascum insulare Boiss. and Heldr.: Evaluation of antimicrobial, anticancer, antioxidant properties and photocatalytic degradation of MB
(Elsevier B.V., 2024) Hazman, Ömer; Khamidov, Gofur; Yılmaz, Mustafa Abdullah; Bozkurt, Mehmet Fatih; Kargioğlu, Mustafa; Savrik, Mehmet; Tukhtaev, Davlat; 0000-0002-2702-6847; 0000-0001-7347-1522; 0000-0002-4090-7227; 0000-0002-2427-2225; 0000-0001-7239-2427
In recent years, due to the environmental friendliness of nanoparticle production, biosynthesis methods using plant extracts and possible physical, chemical, thermal and biological properties of the synthesized nanoparticles are frequently the subject of research. In the present study, hydrothermally assisted synthesis of Ag nanoparticles using twig-leaf extract of Verbascum insulare Boiss. and Heldr., (VIE-AgNPs) a plant endemic to Turkey, was successfully carried out for the first time in this study. The presence of 24 of the 53 phytochemicals investigated in the content of the extract of Verbascum insulare Boiss. and Heldr. (VIE) determined by the LC-MS/MS system was detected. In addition, the amount of phenolic substance involved in reduction was found to be 60.42 ± 9.11 µg Gallic acid equivalent/mg-extract. The synthesized AgNPs were characterized by UV–visible spectra (UV–vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), and X-ray diffraction (XRD). In particular, the surface plasmon band observed at 422 nm, the characteristic peaks observed in XRD, and the bond energy values seen in XPS strongly confirmed the formation of AgNPs. XRD and TEM data showed that AgNPs had an average size range of 25–30 nm. FTIR data indicated the presence of some herbal agents on the surface of AgNPs. The properties of the VIE-AgNPs were compared in vitro with chemically produced AgNPs (C-AgNPs). The OSI level of C-AgNPs was 87.78 ± 1.75 AU, while that of VIE- AgNPs was 110.42 ± 7.54 AU. It was observed that the nanoparticle and VIE used in the study had antimicrobial activity. It was determined that its antibacterial activity was stronger than its antifungal activity. When the analyzed inflammatory parameter levels (TNF-?, IL1?, TGF-?, and DEF-?2) were examined, the effect of VIE on inflammation in A549 cells could not be detected. However, it was determined that VIE-AgNPs, one of the nanoparticles used in the study, increased anti-inflammatory levels more than C-AgNPs. When the received data are evaluated together, it can be said that biosynthesized AgNPs suppress proliferation and stimulate apoptosis in cancer cells by increasing oxidative stress and inflammation levels compared to chemical AgNPs, thus showing an anticarcinogenic effect. It was found that VIE-AgNPs could effectively degrade the water pollutant methylene blue (MB) dye. VIE-AgNP mediated 78 % photocatalytic degradation of MB in 180 min. All superior biological properties are thought to be due to the low particle size and the interaction of active components with AgNPs during the biosynthesis process. Because it has been observed that VIE-AgNPs, which have a smaller particle size, have higher biological (cytotoxic, anticarcinogenic, inflammatory, etc.) activities than C-AgNPs. It can be said that AgNPs produced by biosynthesis may have potential use in the production of environmentally friendly, antibacterial/anticarcinogenic materials.
The relationship between the chemical components and skin-related enzyme inhibition, antioxidant activities and toxicity profile of Helichrysum armenium subsp. armenium
(Taylor and Francis Ltd., 2023) Yıldız, Gülsüm; Karatoprak, Gökçe Şeker; İlgün, Selen; Yılmaz, Mustafa Abdullah; Köse, Yavuz Bülent; Zengin, Gökhan
The aerial parts of Helichrysum armenium subsp. armenium were subjected to methanol, ethyl acetate and n-hexane extraction. The extracts were evaluated for their in vitro enzyme inhibitory activity [lipoxygenase (LOX), tyrosinase and elastase], antioxidant activity and toxicity (on fibroblast cells). All the extracts displayed a weak effect on LOX and elastase. The ethyl acetate extract showed the highest inhibition on tyrosinase enzyme with IC50 = 460 µg/mL, while kojic acid had IC50 = 30 µg/mL. The methanol and ethyl acetate extracts compared to the n-hexane extract exhibited stronger DPPH• and ABTS•+ scavenging activity, as well as iron(II)-chelating potential, and were shown to have rich phenolic and flavonoid contents. The methanol extract was toxic to healthy fibroblast cells at a higher concentration with IC50 > 500 µg/mL compared to the other extracts. Phytochemical analysis of the extracts was made quantitatively by LC–MS/MS. The major components identified in the methanol and the ethyl acetate extracts were astragalin, quinic acid, apigenin-7-glycoside, isoquercitrin, chlorogenic acid, naringenin, apigenin and luteolin-7-glucoside. The compounds detected in the n-hexane extract were much fewer. Based on these findings, H. armenium subsp. armenium can be considered to be a natural raw material with the potential to be used in the cosmetic industry.
Comprehensive study of all Gundelia L. taxa exists in the globe: An insight on LC-MS/MS based phytochemical investigation and bioactivity potential of 22 species
(Elsevier Ltd, 2023) Tarhan, Abbas; Fırat, Mehmet; Topal, Giray
Species from the Gundelia genus are among the important main therapeutic herbs widely used in Middle Eastern nations' traditional medicine. The emphasis of the current investigation was on the bioactive phytochemicals and biopharmaceutical efficacy of all 22 species of Gundelia taxa worldwide. Herewith, ethanolic extracts of root, stem-leaf and flower parts of twenty two Gundelia species were prepared and their bioactive phytochemicals were quantified by a comprehensive and validated LC-MS/MS (liquid chromatography tandem mass spectrometry) method. The results of the LC-MS/MS study revealed that, chlorogenic acid (0.042–93.52 mg/g extract), quinic acid (3.860–63.761 mg/g extract), kaempferol-3-O-glucoside (0.019–42.737 mg/g extract), luteolin-7-O-glucoside (cymaroside) (0.013–34.017 mg/g extract), quercetin-3-O-glucoside (0.021–24.241 mg/g extract), apigenin-7-O-glucoside (0.006–15.859 mg/g extract), 1,5-dicaffeoylquinic acid (0.014–4.827 mg/g extract) and caffeic acid (0.020–4.082 mg/g extract) amounts were remarkable in the overall assessment of the quantification results. Furthermore, bioactivities of the studied extracts were determined by evaluating total phenolic-flavonoid contents and ABTS (cation radical scavenging activity), DPPH (free radical scavenging activity) and CUPRAC (cupric reducing antioxidant capacity) antioxidant test assays. With a few exceptions, all antioxidant test assays showed that the root ethanol extracts of the examined Gundelia species had stronger antioxidant activity than their flower and stem-leaf extract counterparts. Based on the results of the ABTS assay, it was discovered that the antioxidant capacities of root-ethanol extracts of G. purpurascens, G. dersim, G. armeniaca, G. armata, G. aragatsi, G. microcephala, G. tournefortii and G. tehranica (IC50 < 10 μg/mL) were at least as high as those of BHT (Butylated hydroxytoluene) (IC50: 11.35 ± 0.22 μg/mL) and α-tocopherol (IC50: 9.23 ± 0.12 μg/mL), which were used as the reference compounds. To conclude, this is the first study in which the phytochemical contents and antioxidant activities of different parts of all Gundelia taxa in the world were determined together. Moreover, in this study, the phytochemical quantitation and bioactivity of G. microcephala, G. cappadocica, G. tehranica, G. aragatsi, and G. tenuisecta species were evaluated for the first time.
Biosynthesis, characterization, and investigation of antimicrobial and cytotoxic activities of silver nanoparticles using Solanum tuberosum peel aqueous extract
(Elsevier Ltd., 2023) Xu, Jiajun; Yıldıztekin, Mahmut; Han, Dayong; Keskin, Cumali; Baran, Ayşe; Baran, Mehmet Fırat; Ava, Canan Aytuğ; Kandemir, Sevgi İrtegün
Metallic nanoparticle biosynthesis is thought to offer opportunities for a wide range of biological uses. The green process of turning biological waste into utilizable products gaining attention due to its economical and eco-friendly approach in recent years. This study reported the ability of Solanum tuberosum (ST) peel extract to the green synthesis of non-toxic, stable, small-sized silver nanoparticles without any toxic reducing agent utilizing the phytochemical components present in its structure. UV–visible spectroscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, flourier scanning electron microscopy, atomic force microscopy, transmission electron microscopy, and energy dispersive analysis X-ray confirmed the biosynthesis and characterization of silver nanoparticles. Also, dynamic light scattering and thermogravimetric analyses showed stable synthesized nanoparticles. The antibacterial activity of the biosynthesized silver nanoparticles was evaluated against four different bacterial strains, Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) Bacillus subtilis (B. subtilis), and a yeast, Candida albicans (C. albicans) using the minimum inhibitory concentration technique. The cytotoxic activities were determined against Human dermal fibroblast (HDF), glioblastoma (U118), colorectal adenocarcinoma (CaCo-2), and human ovarian (Skov-3) cell lines cancer cells using MTT test. The nanoparticle capping agents that could be involved in the reduction of silver ions to Ag NPs and their stabilization was identified using FTIR. Nanoparticles were spherical in shape and had a size ranging from 3.91 to 27.07 nm, showed crystalline nature, good stability (−31.3 mV), and the presence of capping agents. ST-Ag NPs significantly decreased the growth of bacterial strains after treatment. The in vitro analysis showed that the ST-Ag NPs demonstrated dose-dependent cytotoxicity against cell lines. Based on the data, it is feasible to infer that biogenic Ag NPs were capped with functional groups and demonstrated considerable potential as antibacterial and anticancer agents for biomedical and industrial applications.
Assessment of antimicrobial and antioxidant activities of nepeta trachonitica: Analysis of its phenolic compounds using HPLC-MS/MS
(MDPI, 2017) Köksal, Ekrem; Tohma, Hatice; Kılıç, Ömer; Alan, Yusuf; Aras, Abdülmelik; Gülçin, İlhami; Bursal, Ercan
Continuing our work on the sources of natural bioactive compounds, we evaluated the antimicrobial and antioxidant activities of Nepeta trachonitica as well as its major phenolic content using the high-performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS) technique. For antioxidant activity, ferric reducing antioxidant power (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) methods were performed to measure the reducing power and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was employed to evaluate the radical scavenging activity of the sample. For antimicrobial activity, three Gram-positive and four Gram-negative microbial species as well as three fungi species were tested. N. trachonitica appeared to have reasonable antioxidant activity and decent antimicrobial activity as indicated by the inhibition of the organisms’ growth. The most susceptible species were Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 11229 among the organisms tested. Ethanol extract of the plant has the highest effect on Saccharomyces cerevisiae but no effect on Yarrowia lipolytica. The HPLC-MS/MS analysis showed that at least 11 major phenolic compounds of N. trachonitica exist, the major ones being rosmarinic acid, chlorogenic acid and quinic acid. The obtained results suggest that N. trachonitica could be a promising source for food and nutraceutical industries because of its antimicrobial and antioxidant properties and phenolic compounds.
A research on the chemical, mineral and fatty acid compositions of two almond cultivars grown as organic and conventional in southeastern Turkey
(CSIC Consejo Superior de Investigaciones Cientificas, 2022) Gülsoy, Ersin; Tarhan, Abbas; İzol, Ebubekir; Çokran, Berna Doğru; Şimşek, Mikdat
Organic farming is a human and environment friendly production system that is based on soil fertility and food safety without using chemical fertilizers and pesticides in production, aiming to re-establish the deteriorated ecological balance as a result of harmful production practices. Organic products attract the interest of consumers as they are strongly perceived as healthier products compared to conventional food. This study aimed to determine the differences in chemical, mineral, and fatty acid characteristics between conventionally and organically cultivated Ferragnes and Ferraduel almond cultivars. When conventional and organic almonds were evaluated in terms of fatty acids, proximate compositions, and minerals, crude oil and Mg were statistically insignificant, while Cu was significant (P < 0.05) and all others were quite significant (P < 0.001). Total sugar was higher in organic samples compared to conventional samples in both cultivars. The crude oil and linoleic acid (12.93% for Ferragnes and 14.99% for Ferraduel) were higher in conventional samples but oleic acid (78.9% for Ferragnes and 81.08% for Ferraduel) was higher in organic samples. In addition, organic samples contained higher Mg and Fe but lower P, K, Ca, Na, Zn, Mn and Cu when compared with conventional samples. The results indicate that conventionally cultivated almonds present higher mineral content and lower fatty acid value compared to organically cultivated almonds.
Investigation of the structural and morphological features of TiO2:8OBA composites for MIS semiconductor diodes
(Elsevier Ltd, 2023) Güllü, Ömer; Okumuş, Mustafa; Ava, Canan Aytuğ
In this study, a liquid crystal 8OBA-doped TiO2 composite was formed on a p-Si substrate using the ultrasonic spray coating method. The characterization of the un-doped and doped films produced was carried out by SEM-EDS, XRD and UV–vis measurements. SEM/EDS analysis showed that the TiO2:8OBA composite completed the formation of a layer on the glass surface and exhibited a homogeneous distribution throughout the surface. XRD analysis of TiO2:8OBA composites showed that anatase and rutile crystal phases are belonging to TiO2 and C[sbnd]H based phase indicating 8OBA. In addition, as a result of UV–vis analysis, the optical band gap of 8OBA:TiO2 composite was calculated as 2.82 eV. Besides, the diode application of 8OBA doped and un-doped TiO2 thin film was performed. Charge transport processes of the diode were studied in detail by taking current–voltage measurements. The ideality factor, barrier height, series resistance and parallel resistance values were extracted using different methods.
Trace element analysis of some medicinal and aromatic plant taxa by ICP-MS
(Bingöl Üniversitesi Fen Bilimleri Enstitüsü, 2023) İzol, Ebubekir; Çiçek, İsa; Behçet, Lütfi; Kaya, Enes; Tarhan, Abbas
In this study, analysis of trace elements (Al, V, Cr, Ni, Cu, Zn, As, Ag, Cd, Sn, Hg, Pb) in medicinally important taxa, such as Alkanna trichophila Hub.-Mor. var. trichophila, Anchusa azurea Mill. var. azurea (Boraginaceae), Achillea biebersteinii Afan., Centaurea iberica Trev. ex Sprengel (Asteraceae), Ajuga vestita Boiss. (Endemic), Teucrium polium L. (Lamiaceae), collected in Çermik district of Türkiye’s Diyarbakır province, was conducted quantitatively and qualitatively using the ICP-MS technique. Today, ICP-MS technology is one of the most sensitive metal analysis methods. As a result of the analysis, Sn, Hg, and Pb elements in the studied plant taxa could not be determined since they were below the LOD value. It is essential for consumers that these three toxic elements are not specified in plant species. In general, it was determined that the concentrations of heavy metals, which have harmful effects on health, were low in the investigated plants. Of all the elements, Al (26.04- 193.5 mg/kg) had the highest concentration in the studied taxa. As a consequence, several trace elements were characterized, and their concentrations were identified in the studied medicinal and aromatic six ethnobotanically important plant species.
The diving beetle fauna of diyarbakir and bingöl provinces, Turkey (coleoptera: Dytiscidae) with a new record
(University of Punjab (new Campus), 2018) Aykut, Medeni
The present study was carried out from September 2013 to August 2015 in Bingöl and Diyarbakır provinces in the Eastern and South-eastern Anatolian regions of Turkey. A total of 3,990 dysticid specimens were collected from 118 different localities and identified. In total, 40 species in 17 genera of family Dytiscidae were recorded, of which 37 were new to the study area. Eretes sticticus (Linnaeus, 1767) is the second record for Turkish fauna. Furthermore, Hydroporus inscitus Sharp, 1882 is new record for the Turkish fauna.
In vitro enzyme inhibitory properties, antioxidant activities, and phytochemical fingerprints of five Moroccan seaweeds
(Elsevier B.V., 2020) Grina, Fatiha; Ullah, Zain; Kaplaner, Erhan; Moujahid, Abderrahman; Eddoha, Rabiaa; Nasser, Boubker; Ertaş, Abdulselam; Öztürk, Mehmet
The coastlines of Morocco have an abundant resource of diverse seaweeds but the bioactivity of many of these seaweeds is still unexplored. The aim of this study was to contribute to the evaluation of the antioxidant potential, using different in vitro systems and searching some fingerprints of phenolic constituents based on LC-MS/MS method of five seaweeds species obtained from Moroccan Atlantic Ocean: Bifurcaria bifurcata, Cystoseira humilis, Cystoseira stricta, Fucus spiralis and Gelidium sesquipedale. The total phenolic compounds, the antioxidant activity, anticholinesterase, tyrosinase inhibitory, urease inhibitory activities and the organic compounds were determined. The results showed that Fucus spiralis possessed the highest phenolic and flavonoid contents compared to the others. In addition, Fucus spiralis (IC50: 13.25 ± 0.9 µg/mL) and Cystoseira stricta (IC50: 13.58 ± 1.2 µg/mL) exhibited higher lipid peroxidation inhibitory activity. The highest1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC50: 47.23 ± 3.8 µg/mL), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) dia-mmonium salt (ABTS) (IC50: 5.95 ± 0.6 µg/mL), and Cupric reducing antioxidant capacity (CUPRAC) (55.24 ± 0.04 µg trolox equivalents/mg) activity was measured in Fucus spiralis. Regarding metal chelating activity, Bifurcaria bifurcata was the best (IC50: 45.22 ± 0.9 µg/mL) compared to the others. The highest acetylcholinesterase (IC50: 28.92 ± 1.8 µg/mL), butyrylcholinesterase (IC50: 11.72 ± 2.8 µg/mL), tyrosinase (IC50: 6.19 ± 0.4 µg/mL) and urease (IC50: 10.96 ± 1.3 µg/mL) inhibitory activities was found in Fucus spiralis. According to LC-MS/MS results, quinic acid, malic acid, fumaric acid, gallic acid, protocatechuic acid, 4-OH-benzoic acid, hesperidin, were detected in ethanol extracts of the five Moroccan seaweeds. This study demonstrated that seaweeds, particularly Fucus spiralis and Cystoseira stricta could be a promising source of antioxidants and phytochemicals which can be used in cosmetics, pharmaceutical and as nutritional food supplement in food industries to deleterious free radical induced stress, disorder and diseases.
Electro-deposited halloysite nanotube/polyaniline nanocomposites for energy storage applications
(Elsevier B.V., 2023) Aljawrneh, Bashar; Albiss, Borhan Aldeen; Rahman, Mohammad Abdel; Ocak, Yusuf Selim
A nanocomposite (nanoclay/conductive polymer) was prepared by a template-free method for supercapacitor applications. Halloysite Nanotubes (HNTs) were used as a nanoclay material, and synthesized polyaniline (PANI) by ammonium persulfate-initiated polymerization was used as a conductive polymer. The HNTs/PANI nanocomposite was deposited on an indium tin oxide (ITO) coated glass to obtain a working electrode by an electrochemical deposition method. Morphological and structural examination of the HNTs/PANI nanocomposite proved that the PANI nanoparticles were attached to the HNTs surface. The structural analysis demonstrated that the PANI and HNTs crystal size significantly decreased in the HNTs/PANI as a result of the composition of PANI molecules with HNTs structure. The main characteristic bonds and functional groups of HNT, PANI, and HNTs/PANI nanocomposites were determined by FT-IR analysis. Using cyclic voltammetry (CV), the electrochemical performance of the HNTs//PANI nanocomposite electrode was investigated. The specific capacitance values were reported via the CV curves as 264, 230.22, 175.2, and 154.8 F/g at scan rates of 50, 100, 200, and 300 mV/s respectively. The results showed that the specific capacitance at the slow scan rates revealed higher maximum specific capacitance values.
Moleküler baskılama temelli kuvars kristal mikroterazi (QCM) sensörler ile klorpirifos tayini
(Iğdır Üniversitesi Fen Bilimleri Enstitüsü, 2019) Çakır, Oğuz
Pestisitler tarımsal üretimin kontrolü gibi pek çok alanda yaygın olarak kullanılmaktadır. Bu maddeler tarımsal ürünlerin artmasına katkıda bulunur ancak toksik özelliklerinden dolayı canlılar üzerinde olumsuz etkilere sebep olmaktadır. Bu nedenle pestisitlerin tayin edilmesi, hem insanlar üzerinde artan toksik etkilerinden hem de kullanımının kontrol altına alınmasından dolayı büyük bir öneme sahiptir. Bu çalışmada, çevre sularında oldukça seçici, hassas, hızlı ve gerçek zamanlı bir ölçüm ile klorpirifos tayini için moleküler baskılama tekniği kullanılarak yeni bir kuvars kristal mikroterazi (QCM) sensör hazırlanmış olup N-metakriloil- (L)-triptofan metil ester (MATrp) uygun fonksiyonel monomer olarak seçilmiştir. Daha sonraki aşamada bu monomer kompleksi etilen glikol dimetakrilat (EGDMA) ile polimerleştirilmiştir. Polimerleştirilmiş klorpirifos baskılı nanofilmler QCM sensör çiplerinin altın yüzeylerine bağlanarak temas açısı ölçümleri ve atomik kuvvet mikroskobu (AFM) ile karakterizasyonları yapılmıştır. Kalınlık ölçümleri ve AFM görüntüleri, nanofilmlerin homojen ve tek tabakalı olduğunu göstermiştir. Baskılanmış nanofilmlerin baskılanmamış nanofilmlere oranla daha fazla hedef moleküle duyarlılık gösterdiği belirlenmiştir. Langmuir adsorpsiyon modeli, bu afinite sistemi için en uygun model olarak belirlenmiştir. Klorpirifos baskılanmış nanofilmlerin seçiciliğini göstermek için aynı derişimdeki klorpirifos, diazinon ve paration çözeltilerinin yarışmalı adsorpsiyonu araştırılmıştır. Sonuç olarak, QCM sensörlerin hızlı yanıt, kullanım kolaylığı, yüksek hassasiyet ve seçicilik ve gerçek zamanlı ölçüm alınabilme gibi özelliklerinden dolayı pestisit analizleri için alternatif bir yöntem olarak kullanılma potansiyeline sahip olduğu belirlenmiştir.
Pestisit tayini için manopartiküllerle duyarlılığı arttırılmış moleküler baskılama temelli yüzey plazmon rezonans sensörlerin hazırlanması
(Iğdır Üniversitesi Fen Bilimleri Enstitüsü, 2018) Çakır, Oğuz; Bakhshpour, Monireh; Yılmaz, Fatma; Baysal, Zübeyde
Pestisitler yıllardır tarım alanlarında kullanılmaktadır. Ancak bu yaygın kullanım, bilimsel ve endüstriyel topluluklarda pestisitlerin uzun vadeli insan sağlığı riskleri üzerine bilinen toksisitelerinden dolayı endişeyi arttırmıştır. Böylelikle pestisitlerin tayin edilmesi, hem insanlar üzerinde artan toksik etkilerinden hem de kullanımının kontrol altına alınmasından dolayı büyük bir öneme sahiptir. Bu çalışmada, seçici, hassas, hızlı ve gerçek zamanlı klorpirifos tayini için ilk olarak, poli[etilenglikol dimetakrilat-N-metakriloil-(l)-triptofan metil ester poly(EGDMA-MATrp) nanopartikülleri hazırlandı ve zeta sizer ile karakterize edildi. Ardından, klorpirifos baskılı SPR nanosensör hazırlanarak atomik kuvvet mikroskobu (AFM) ve temas açısı ölçümleri ile karakterize edildi. Kalınlık ölçümleri ve AFM görüntüleri, nanopartiküllerden oluşan ince filmlerin hemen hemen tek tabakalı olduğunu gösterdi. Baskılanmış ve baskılanmamış nanosensörlerin klorpirifos tayin duyarlılığı 0.015-2.9 nM aralığında klorpirifos çözeltileri ile araştırıldı. Baskılanmış nanopartiküllerin, baskılanmamışlara göre daha fazla duyarlılık gösterdiği belirlendi. Langmuir adsorpsiyon modeli, bu afinite sistemi için en uygun model olarak belirlendi. Klorpirifos baskılanmış nanopartiküllerin seçiciliğini göstermek için 2.9 nM derişimindeki klorpirifos, diazinon ve parationun yarışmalı adsorpsiyonu araştırıldı. Sonuç olarak, SPR nanosensörlerin hızlı yanıt, kullanım kolaylığı, hassasiyet, seçicilik ve gerçek zamanlı ölçüm alınabilme özelliğinden dolayı pestisit analizleri için alternatif bir yöntem olarak kullanılma potansiyeline sahip olduğu görüldü.
The investigation of the chemical composition and applicability of gold nanoparticles synthesized with amygdalus communis (Almond) leaf aqueous extract as antimicrobial and anticancer agents
(MDPI, 2023) Baran, Mehmet Fırat; Keskin, Cumali; Baran, Ayşe; Eftekhari, Aziz; Omarova, Sabina; Khalilov, Rovshan; Ava, Canan Aytuğ
The current work’s main objective was to determine the chemical composition of Amygdalus communis (AC) leaf extract and examine the antibacterial and cytotoxic properties of biosynthesized gold nanoparticles (AuNPs). The chemical composition of AC leaf extract was determined using LC-ESI/MS/MS to detect compounds that may be responsible for the reducing, stabilizing, and capping steps in the synthesis of nanoparticles and their biological activities. The AC-AuNPs were spherical, with a particle size lower than 100 nm and a face-centered cubic structure. The EDX spectrum confirmed the formation of AuNPs and a negative zeta potential value (−27.7 mV) suggested their physicochemical stability. The in vitro cytotoxic efficacy of the AC-AuNPs against colorectal adenocarcinoma (Caco-2), glioma (U118), and ovarian (Skov-3) cancer cell lines and human dermal fibroblasts (HDFs) was evaluated by MTT assay. CaCo-2 cell proliferation was effectively inhibited by the AC-AuNPs at concentrations between 25 and 100 g mL−1. The AC-AuNPs exerted preeminent antimicrobial activity against Bacillus subtilis with an MIC of 0.02 μg/mL, whilst good activity was shown against Staphylococcus aureus bacteria and Candida albicans yeast with an MIC of 0.12 μg/mL. Ultimately, the results support the high antibacterial and anticancer potential of biosynthesized AuNPs from AC leaf extract.
Structural and electronic characterization of silicon based MIS contact by xanthene dye molecules (Erythrosine B)
(Elsevier B.V., 2023) Sunkur, Murat; Ava, Canan Aytuğ; Güllü, Ömer
The effect of erythrosine B (ERY) organic material as an interface layer on the electronic characteristics of the Al/p-Si junction is examined in the present work. AFM, NMR, UV–Vis and FTIR measurements have been conducted on the ERY dye molecule. The ERY film on the surface of the substrate is coated with nanoparticles, according to the surface analysis performed using the AFM technique. The basic diode parameters of Al/p-Si and Al/ERY/p-Si junctions were measured by utilizing current-voltage (I–V) and capacitance-voltage (C-V) techniques. The junctions with and without organic interfacial layers were found to have ideality factors of 1.931 and 1.925, respectively. For MS and MIS contacts, the estimated values of barrier height were 0.592 eV and 0.937 eV, respectively. Additionally, the series resistances for the MS and MIS structures by utilizing Norde function, were determined to be 0.14 kΩ and 322.85 kΩ, respectively. In addition, the reverse bias 1/C2-V characteristics were used to analyze the barrier height values and compare the findings to those from I-V method. The experimental findings demonstrated that the Al/ERY/p-Si MIS diode has a barrier height that is remarkably greater than that of the reference Al/p-Si junction. Placement of the ERY dye interlayer between a metal and a semiconductor could enhance and regulate the performance and characteristic of these types of junctions.
Phytochemical profile, antioxidant and antimicrobial potency of aerial parts of Salvia tomentosa Miller
(Slovensko Kemijsko Drustvo, 2023) Balkır, Şehnaz; Hazman, Ömer; Aksoy, Laçine; Yılmaz, Mustafa Abdullah; Çakır, Oğuz; Kara, Recep; Erol, İbrahim
Antioxidant activity, antimicrobial potency and components of the aerial parts (leaf, stem, flower and mixture) of Salvia tomentosa Miller were determined qualitatively and quantitatively in this study. Aqueous extracts of Salvia tomentosa(ST) were prepared by using the flower, leaf and stem parts and all the above-ground parts of the plant (flower-leaf-stem mixture) for this purpose. The radical scavenging activity, total antioxidant/oxidant status, antimicrobial potential, phenolic substances and qualitative/quantitative analyzes of the components in the extracts were determined. ST-stem phenolic acid amount (599 ± 34 mg gallic acid equivalent (GAE)/g extract) was found to be close to the standard sub-stance caffeic acid (651 ±3 1 mg GAE/g extract). Total antioxidant status of ST-mix (3.4 ± 0.1 mmol Trolox Equiv./L) and ST-stem (3.4 ± 0.1 mmol Trolox Equiv./L) and natural antioxidant Vitamin C (3.6 ± 0.1 mmol Trolox Equiv./L) were not statistically different. The extract produced by using S. tomentosa aerial parts (flower-stem-leaf ) showed stronger antioxidant and antimicrobial activity than the aqueous extracts obtained separately from the flower, stem and leaf of the plant. However, it was determined that the components of the separately prepared flower, stem and leaf extracts and the extract components obtained from the aerial parts were largely similar. At the same time, it was observed that there were significant differences in the presence of these components.
Development and validation of a novel LC-MS/MS method for the quantitation of 19 fingerprint phytochemicals in salvia species: A chemometric approach
(Oxford University Press, 2022) Yılmaz, Mustafa Abdullah; Ertaş, Abdulselam; Yener, İsmail; Ölmez, Özge Tokul; Fırat, Mehmet; Temel, Hamdi
Being traditionally utilized mainly as appetizers and herbal teas as well as used to ease abdominal pains, colds and gastrointestinal issues, the genus Salvia L. has gained significant consideration owing to its remarkable phytochemicals and industrial importance. The present study aimed to develop and validate an LC-MS/MS method for the qualitative and quantitative investigation of 19 fingerprint phytochemicals in six endemic Salvia species. The validation parameters of the developed LC-MS/MS method were repeatability (intermediate precision), recovery (accuracy), limits of detection and quantification, linearity and uncertainty (U% at 95% confidence level (k = 2)). Reversed-phase HPLC separation and mass spectrometry parameters were optimized for each analyte. Ethanol extracts of the studied Salvia species collected in three consecutive years were screened for their fingerprint phytochemicals by using the developed and validated LC-MS/MS method. Moreover, studied Salvia species were subjected to multivariate analysis such as principal component analysis techniques to demonstrate the variabilities in phytochemical contents by years and parts of the samples. Roots, flowers, leaves, branches and whole plant of the Salvia species collected in 2015, 2016 and 2017 were used for the analyses. It was observed that the roots and branches of Salvia species were similar in terms of their salvianolic acid A, caffeic acid, and 6,7-dehydroroyleanone components. Accordingly, apigenin, rosmarinic acid, luteolin 7-O-glucoside, caffeic acid, salvianolic acid B, and 6,7-dehydroroyleanone were notable phytochemicals that were present in the studied Salvia species.

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