Abdullah Kepceoğlu

Dr. Abdullah Kepceoğlu

SSRL, SLAC National Accelerator Laboratory, Menlo Park, California, USA
+2
orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2023 in TURKISH JOURNAL OF BIOLOGY
Verified
Journal Article
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NANecati̇ Atalay
Necati̇ Atalay
EAEnver Kami̇l Akcan
Enver Kami̇l Akcan
Mehmet GulMehmet Gul
Mehmet Gul
EAEsra Ayan
Esra Ayan
EDEbru Destan
Ebru Destan
Hasan DeMirciHasan DeMirci
Hasan DeMirci
X-ray crystallography is a robust and powerful structural biology technique that provides high-resolution atomic structures of biomacromolecules. Scientists use this technique to unravel mechanistic and structural details of biological macromolecules (e.g., proteins, nucleic acids, protein complexes, protein-nucleic acid complexes, or large biological compartments). Since its inception, single-crystal cryocrystallography has never been performed in Türkiye due to the lack of a single-crystal X-ray diffractometer. The X-ray diffraction facility recently established at the University of Health Sciences, İstanbul, Türkiye will enable Turkish and international researchers to easily perform high-resolution structural analysis of biomacromolecules from single crystals. Here, we describe the technical and practical outlook of a state-of-the-art home-source X-ray, using lysozyme as a model protein. The methods and practice described in this article can be applied to any biological sample for structural studies. Therefore, this article will be a valuable practical guide from sample preparation to data analysis.

10 May 2015 in Lasers in Medical Science
Verified
Journal Article
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YAYusuf Z. Akpinar
Yusuf Z. Akpinar
Abdullah KepceoğluAbdullah Kepceoğlu
Abdullah Kepceoğlu
TYTevfik Yavuz
Tevfik Yavuz
MAMuhammed A. Aslan
Muhammed A. Aslan
ZDZulfikar Demirtag
Zulfikar Demirtag
AUAslihan Usumez
Aslihan Usumez

19 May 2023 in Scientific Reports
Verified
Journal Article
Open access
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MGMehmet Gul
Mehmet Gul
EAEsra Ayan
Esra Ayan
EDEbru Destan
Ebru Destan
JJJ. Austin Johnson
J. Austin Johnson
ASAlaleh Shafiei
Alaleh Shafiei
Hasan DeMirciHasan DeMirci
Hasan DeMirci
High-resolution biomacromolecular structure determination is essential to better understand protein function and dynamics. Serial crystallography is an emerging structural biology technique which has fundamental limitations due to either sample volume requirements or immediate access to the competitive X-ray beamtime. Obtaining a high volume of well-diffracting, sufficient-size crystals while mitigating radiation damage remains a critical bottleneck of serial crystallography. As an alternative, we introduce the plate-reader module adapted for using a 72-well Terasaki plate for biomacromolecule structure determination at a convenience of a home X-ray source. We also present the first ambient temperature lysozyme structure determined at the Turkish light source (Turkish DeLight). The complete dataset was collected in 18.5 min with resolution extending to 2.39 Å and 100% completeness. Combined with our previous cryogenic structure (PDB ID: 7Y6A), the ambient temperature structure provides invaluable information about the structural dynamics of the lysozyme. Turkish DeLight provides robust and rapid ambient temperature biomacromolecular structure determination with limited radiation damage.

19 November 2014 in Journal of Adhesion Science and Technology
Verified
Journal Article
Closed access
YAYusuf Ziya Akpinar
Yusuf Ziya Akpinar
TYTevfik Yavuz
Tevfik Yavuz
MAMuhammed Ali Aslan
Muhammed Ali Aslan
Abdullah KepceoğluAbdullah Kepceoğlu
Abdullah Kepceoğlu
HKHamdi Sukur Kilic
Hamdi Sukur Kilic
Objective: The purpose of this study was to evaluate the effect of different surface shapes formed by femtosecond (FS) laser on zirconia (Y-TZP)-resin cement shear bond strength (SBS). Background data: All ceramic restoration is used as an alternative to metal-ceramic restorations, due to its better aesthetics, strength, and toughness properties. However, bond strength of restoration to tooth and other materials is effective to long term success of the restoration, and to achieve it surface treatment is required on ceramic surface. Materials and methods: Forty square-shaped zirconia samples were prepared and assigned to four groups of 10. The details of the groups are as follows: Group A, square-shaped recessed surface; Group B, square-shaped projection surface; Group C, circular-shaped recessed surface; Group D, circular-shaped projection surface. The SBSs values were performed with a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed statistically using analysis of variance (ANOVA) and Tukey HSD multiple comparisons tests. Results: The one-way ANOVA results on SBSs of the zirconia material bonded with resin cement revealed significant differences among the groups (p < 0.05). The Tukey HSD test results revealed that Group B and D had significantly higher SBS values than other groups (p < 0.05), but there were no significant differences between each other (p > 0.05). Additionally, Group A and C had significantly lower values than other groups (p < 0.05). Conclusions: Different surface shapes formed by FS laser provided a significant increase in SBSs. The SBS values of projection surfaces of circular and square-shapes are greater than that of recessed surfaces of circular and square-shapes.

31 May 2020 in Nanomaterials
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Journal Article
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SGSerap Yiğit Gezgin
Serap Yiğit Gezgin
Abdullah KepceoğluAbdullah Kepceoğlu
Abdullah Kepceoğlu
YKYasemin Gündoğdu Kabakcı
Yasemin Gündoğdu Kabakcı
SZSidiki Zongo
Sidiki Zongo
Anna ZawadzkaAnna Zawadzka
Anna Zawadzka
Bouchta SahraouiBouchta Sahraoui
Bouchta Sahraoui
In this study, the thin films were produced by using pulsed laser deposition (PLD) technique from gold (Au) nanoparticles deposited on two kinds of substrates under different argon (Ar) gas pressure. Microscope glass slides and silicon (100) wafers were used as amorphous and crystal substrates. The films were deposited under 2 × 10−3 mbar, 1 × 10−2 mbar, 2 × 10−2 mbar argon (Ar) ambient gas pressure. Effect of the background gas pressure on the plasma plume of the ablated Au nanoparticles was investigated in details. Morphology of Au nanoparticle thin films was investigated by means of atomic force microscopy (AFM) technique. Absorption spectra of Au nanoparticles were examined by using UV-Vis spectrometry. Extinction spectra of Au nanoparticles were calculated by using metallic nano particles boundary element method (MNPBEM) simulation programme. Both experimental spectra and simulation data for Au nanoparticles were obtained and compared in this work. It was concluded that they are also in good agreement with literature data. The measurements and the simulation results showed that localized surface plasmon resonance (LSPR) peaks for Au nanoparticles were located in the near infrared region (NIR) because of the larger size of the disk-like shape of Au nanoparticles, and the near-field coupling between Au nanoparticles. It was demonstrated that as the ambient gas (Ar) pressure was increased, the size and the density of Au nanoparticles on the substrate were decreased and the LSPR peak shifts toward the short wavelength region in the spectrum. This shift has been explained by the changes in the morphology of produced thin films.

1 June 2014 in Biomedicine & Pharmacotherapy
Verified
Journal Article
Closed access
MKMeltem Demirel Kars
Meltem Demirel Kars
RKReyhan Kara
Reyhan Kara
YGYasemin Gündoğdu
Yasemin Gündoğdu
Abdullah KepceoğluAbdullah Kepceoğlu
Abdullah Kepceoğlu
HKHamdi Şükür Kılıç
Hamdi Şükür Kılıç