Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 3Citation - Scopus: 5Feedback Controller Designs for an Electromagnetic Micromanipulator(Sage Publications Ltd, 2019-09-09) Boyuk, Mustafa; Eroglu, Yakup; Ablay, Gunyaz; Icoz, KutayMagnetic micromanipulators are capable of generating wide range of magnetic forces to manipulate magnetic microparticles for biomedical applications. In this study, a multipole magnetic micromanipulator system including electromagnets, driver circuitry and control unit is designed, modeled and implemented. The micromanipulator can produce a broad range of magnetic forces up to 25 pN on a single magnetic microparticle (1-10 mu m diameter) that is 5 mm away from the electromagnet core tip. Both linear and nonlinear controllers are designed and implemented, and the proposed nonlinear controller produces smooth control currents to assure closed-loop stability of the system with 1 s non-overshoot transient response and zero steady-state tracking error. The maximum output current of the driver circuitry is set to 1 A. The single particle at the center is moved at a speed of 5 mm/s. The fully automatic system can be utilized in applications related to single cell or microparticle manipulations.Article Citation - WoS: 1Citation - Scopus: 2Do Digitalization and Green Innovation Limit Carbon Emissions? Evidences From BRICS Economies(Sage Publications Ltd, 2024-10-30) Zhang, Hong; Dogan, Eyup; Khan, Zeeshan; Binsaeed, Rima H.Rapidly evolving innovation and digitalization have captured the focus of policymakers and scholars regarding their potent role in influencing environmental quality. The present research analyzes the impact of these variables on the carbon emissions of Brazil, Russia, India, China, and South Africa economies from 1990 to 2021. This research also explores the impact of economic growth, quadratic green innovation, and green energy on carbon emissions. Using several panel diagnostic tests, this research validates heterogeneous slopes, the presence of cross-sectional dependence, and significant cointegration. Due to the mixed integration order, this research uses a cross-sectional augmented autoregressive distributed lag model, and the results show that economic expansion and green innovation are significant drivers of emissions in both the short and long run. However, digitalization, quadratic green innovation, environmental policy stringency, and green energy are significant in improving environmental quality and sustainability. The long-term results are tested by employing a series of parametric and nonparametric regressions. This research recommends further investment in environmental research and development, digital technologies, green innovation, and the strengthening of environmental policies to attain sustainable development.Article Citation - WoS: 5Citation - Scopus: 6Design, Modeling, and Control of a Horizontal Magnetic Micromanipulator(Sage Publications Ltd, 2019-01-31) Ablay, Gunyaz; Boyuk, Mustafa; Icoz, KutayMagnetic micromanipulators with a wide range of force generating capabilities are able to manipulate micron size particles for various applications and measurements. These magnetic particles can be coated with receptors to specifically bind to target biomolecules. In this work, a horizontal magnetic micromanipulator is designed, modeled and controlled for single micron size magnetic particle manipulations. A method is presented for dynamic modeling of magnetic micromanipulators. A feedback control method is designed that allows direct linearization of the system. It is shown that the proposed controller guarantees the stability of the closed-loop system, and yields zero steady-state error in a wide range of operation conditions. We show that the micromanipulator is able to generate a wide range of piconewton (pN) scale forces on a superparamagnetic particle for single molecule separation, and biosensor developments.Article Citation - WoS: 6Citation - Scopus: 6A Molecular and Biophysical Comparison of Macromolecular Changes in Imatinib-Sensitive and Imatinib-Resistant K562 Cells Exposed to Ponatinib(Sage Publications Ltd, 2015-09-15) Yandim, Melis Kartal; Ceylan, Cagatay; Elmas, Efe; Baran, YusufChronic myeloid leukemia (CML) is a type of hematological malignancy that is characterized by the generation of Philadelphia chromosome encoding BCR/ABL oncoprotein. Tyrosine kinase inhibitors (TKIs), imatinib, nilotinib, and dasatinib, are used for the frontline therapy of CML. Development of resistance against these TKIs in the patients bearing T315I mutation is a major obstacle in CML therapy. Ponatinib, the third-generation TKI, is novel drug that is effective even in CML patients with T315I mutation. The exact mechanism of ponatinib in CML has been still unknown. In this study, we aimed to determine the potential mechanisms and structural metabolic changes activated by ponatinib treatment in imatinib-sensitive K562 human CML cell lines and 3 mu M-imatinib-resistant K562/IMA3 CML cell lines generated at our lab. Apoptotic and antiproliferative effects of ponatinib on imatinib-sensitive and 3 mu M-imatinib-resistant K562/IMA3 CML cells were determined by proliferation and apoptosis assays. Additionally, the effects of ponatinib on macromolecules and lipid profiles were also analyzed using Fourier transform infrared spectroscopy (FTIR). Our results revealed that ponatinib inhibited cell proliferation and induced apoptosis as determined by loss of mitochondrial membrane potential, increased caspase-3 enzyme activity, and transfer of phosphatidylserine to the plasma membrane in both K562 and K562/IMA-3 cells. Furthermore, cell cycle analyses revealed that ponatinib arrested K562 and K562/IMA-3 cells at G1 phase. Moreover, ponatinib treatment created a more ordered nucleic acid structure in the resistant cells. Although the lipid to protein ratio increased in imatinib-sensitive K562 cells with a little decrease in the K562/IMA-3 cells, ponatinib treatment indicated significant changes in the lipid composition such as a significant increase in the cellular cholesterol amounts much more in the K562/IMA-3 cells than the sensitive counterparts. Unsaturation in lipids was higher in the resistant cells; however, increases in lipids without phosphate and the number of acyl chains were much higher in the K562 cells. Taken together, all these results showed powerful antiproliferative and apoptotic effects of ponatinib in both imatinib-sensitive and imatinib-resistant CML cells in a dose-dependent manner, and hence, the use of ponatinib for the treatment of TKI-resistant CML patients may be an effective treatment approach in the clinic. More importantly, these results showed that FTIR spectroscopy can detect drug-induced physiological changes in cancer drug resistance.