Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Department: search.filters.department.İzmir Institute of Technology. PhysicsSubject: search.filters.subject.XPS

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Now showing 1 - 4 of 4
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Differences and Similarities in Biophysical and Biological Characteristics Between U87 Mg Glioblastoma and Astrocyte Cells
    (Springer, 2023) Özdil, Berrin; Çalık Kocatürk, Duygu; Altunayar Ünsalan, Çisem; Açıkgöz, Eda; Oltulu, Fatih; Görgülü, Volkan; Uysal, Ayşegül; Öktem, Gülperi; Ünsalan, Ozan; Güler, Günnur; Aktuğ, Hüseyin
    Current cancer studies focus on molecular-targeting diagnostics and interactions with surroundings; however, there are still gaps in characterization based on topological differences and elemental composition. Glioblastoma (GBM cells; GBMCs) is an astrocytic aggressive brain tumor. At the molecular level, GBMCs and astrocytes may differ, and cell elemental/topological analysis is critical for identifying potential new cancer targets. Here, we used U87 MG cells for GBMCS. U87 MG cell lines, which are frequently used in glioblastoma research, are an important tool for studying the various features and underlying mechanisms of this aggressive brain tumor. For the first time, atomic force microscopy (AFM), scanning electron microscopy (SEM) accompanied by energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) are used to report the topology and chemistry of cancer (U87 MG) and healthy (SVG p12) cells. In addition, F-actin staining and cytoskeleton-based gene expression analyses were performed. The degree of gene expression for genes related to the cytoskeleton was similar; however, the intensity of F-actin, anisotropy values, and invasion-related genes were different. Morphologically, GBMCs were longer and narrower while astrocytes were shorter and more disseminated based on AFM. Furthermore, the roughness values of these cells differed slightly between the two call types. In contrast to the rougher astrocyte surfaces in the lamellipodial area, SEM-EDS analysis showed that elongated GBMCs displayed filopodial protrusions. Our investigation provides considerable further insight into rapid cancer cell characterization in terms of a combinatorial spectroscopic and microscopic approach.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 8
    An Interface Study of Crystalline Fe/Ge Multilayers Grown by Molecular Beam Epitaxy
    (Elsevier Ltd., 2011) Tarı, Süleyman
    Fe/Ge multilayers were grown on single crystal Ge(0 0 1) substrates by molecular beam epitaxy. The structural, electronic and magnetic properties of Fe/Ge have been studied. The analysis shows that Fe grows in a layer-by-layer epitaxial growth mode on Ge(0 0 1) substrates at 150 ◦C and no intermixing has been observed. Growth of a crystalline Ge film at 150 ◦C on a single crystal Fe film has been observed. At this temperature Ge films grow by means of the island growth mode according to reflection of high energy electron diffraction patterns. Fe layers of 36nm thickness, deposited at 150 ◦C on Ge(0 0 1) substrates, show two magnetization reversal values indicating the growth of Fe in two different crystal orientations. 36nm thick Fe and Ge layers grown at 150 ◦C in Ge/Fe/Ge/Fe/Ge(0 0 1) sequence shows ferromagnetic behavior, however, the same structure grown at 200 ◦C shows paramagnetic behavior.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Znte/Gaas(2 1 1)b Heterojunction Valence Band Discontinuity Measured by X-Ray Photoelectron Spectroscopy
    (Elsevier Ltd., 2011) Wang, X. J.; Tarı, Süleyman; Sporken, R.; Sivananthan, S.
    Thin ZnTe layers were grown by molecular beam epitaxy on single crystal GaAs(2 1 1)B substrates. Reflection high energy electron diffraction monitored the deoxidation of substrate and entire growth process. Valence band offset was calculated with X-ray photoelectron spectroscopy. Also interface formation of the ZnTe/GaAs was studied. Analysis shows that interface is abrupt and calculated valance band offset is 0.25±0.1 eV and indicates type I alignment. The experimental result agrees well with the theoretical predictions involving interface dipole effect as well as electron affinity rule.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 18
    Xps Study of Pulsed Nd:yag Laser Oxidized Si
    (Elsevier Ltd., 2006) Özyüzer, Gülnur Aygün; Aygün, Gülnur; Atanassova, Elenada A.; Kostov, K.; Turan, Raşit
    X-ray photoelectron spectra (XPS) of thin SiO2 layers grown by pulsed Nd:YAG laser at a substrate temperature of 748 K are presented. The peak decomposition technique combined with depth profiling is employed to identify the composition and chemical states of the film structure. It is established that the oxide is non-stoichiometric, and contains all oxidation states of Si in different amounts throughout the film. The interface Si/laser-grown oxide is not abrupt, and the coexistence of Si2O3 and Si2O suboxides in a relatively wide interfacial region is found. It is concluded that post-oxidation annealing is necessary in order to improve the microstructure of both oxide and near interface region.