Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Paper Magnetic Levitation-Based Endothelial Cell Sorting(Institute of Electrical and Electronics Engineers Inc., 2023) Ozcan, H.A.; Kecili, S.; Tekin, H.C.Cell sorting for rare cells is crucial for diagnostic purposes. Circulating Endothelial Cells (CECs) can be used as cardiovascular disease markers. Due to the rareness of the CECs in the blood, an accurate, easy, cost and time-effective sorting method is a need. Magnetic levitation is a promising technique for observing differences in the average height of endothelial and white blood cells which does not require any labeling. This study aims to show that the magnetic levitation principle can be used for sorting endothelial cells from the blood. By using paramagnetic medium concentrations of 10 mM and 50 mM, the average levitation height between HUVECs used as a model endothelial cells and U937 cells used as model of white blood cells was measured as 65 μm and 32 μm, respectively. Since there is a significant difference in levitation height for HUVECs and U937 cells, magnetic levitation technology exhibits promising potential for the precise sorting of endothelial cells. © 2023 IEEE.Conference Object Citation - WoS: 5Citation - Scopus: 3Hierarchical Successive Stream Selection for Heterogeneous Network Interference(Institute of Electrical and Electronics Engineers Inc., 2014) Aycan, Esra; Özbek, Berna; Le Ruyet, DidierThis paper presents a hierarchical stream selection approach to deal with the interference in a heterogeneous network where different cell types are coexisting with each other to increase the sum capacity. Due to the variety of the transmit powers between the macro and small cells, interference levels are different. The proposed solution hierarchically selects the strongest streams of each cell with a contribution to the sum rate, while constructing the streams via singular value decomposition (SVD). In order to reduce the interference, the channel matrices of the remaining streams are projected orthogonally to the virtual transmit channel and virtual receive channel of the selected stream. The performance evaluations are obtained by considering different locations of small cells with respect to the macro cell. It is shown that the proposed method can dynamically select more streams in heterogeneous networks and achieve higher data rates compared to the existing algorithms. © 2014 IEEE.Conference Object Citation - WoS: 1Citation - Scopus: 1Enabling Cooperation, Resource Allocation and Receiver Selection Across Cells: Complementary Fractional Frequency Reuse(Institute of Electrical and Electronics Engineers Inc., 2013) Bakşi, Saygın; Kaya, Onur; Bıyıkoğlu, TürkerFor a multi-cell multiple access channel, we develop a comprehensive cooperative communication framework: we propose a novel complementary fractional frequency reuse (FFR) strategy tailored specifically for pairwise user cooperation, also taking into account cell sectoring. This strategy allows the cell edge users not only to pool their resources and cooperate across cells, but also to choose the best receiver. We divide the users into cooperating inner and outer user pairs, and assign each pair orthogonal resources using OFDMA. We employ pairwise bidirectional cooperation based on block Markov superposition encoding among user pairs. We derive the achievable rates, while taking into account the geometry dependent interference at the users and the receiver. We find the jointly optimal power allocation, partner selection and receiver selection strategies that maximize the sum rate of the system. We then propose a heuristic matching algorithm, which operates based only on user and receiver locations. We compare the performance of our proposed strategies with several non-cooperative models, and demonstrate that the sum rate can nearly be doubled, while using the same resources. © 2013 IEEE.Article Citation - WoS: 30Citation - Scopus: 32Compartmentalization and Regulation of Mitochondrial Function by Methionine Sulfoxide Reductases in Yeast(American Chemical Society, 2010) Kaya, Alaattin; Koç, Ahmet; Lee, Byung Cheon; Fomenko, Dmitri E.; Rederstorff, Mathieu; Krol, Alain; Lescure, Alain; Gladyshev, Vadim N.Elevated levels of reactive oxygen species can damage proteins. Sulfur-containing amino acid residues, cysteine and methionine, are particularly susceptible to such damage. Various enzymes evolved to protect proteins or repair oxidized residues, including methionine sulfoxide reductases MsrA and MsrB, which reduce methionine (S)-sulfoxide (Met-SO) and methionine (R)-sulfoxide (Met-RO) residues, respectively, back to methionine. Here, we show that MsrA and MsrB are involved in the regulation of mitochondrial function. Saccharomyces cerevisiae mutant cells lacking MsrA, MsrB, or both proteins had normal levels of mitochondria but lower levels of cytochrome c and fewer respiration-competent mitochondria. The growth of single MsrA or MsrB mutants on respiratory carbon sources was inhibited, and that of the double mutant was severely compromised, indicating impairment of mitochondrial function. Although MsrA and MsrB are thought to have similar roles in oxidative protein repair each targeting a diastereomer of methionine sulfoxide, their deletion resulted in different phenotypes. GFP fusions of MsrA and MsrB showed different localization patterns and primarily localized to cytoplasm and mitochondria, respectively. This finding agreed with compartment-specific enrichment of MsrA and MsrB activities. These results show that oxidative stress contributes to mitochondrial dysfunction through oxidation of methionine residues in proteins located in different cellular compartments. © 2010 American Chemical Society.