Asuman SAVAŞÇIHABEŞ

Makale/Derleme | 2016 | Turkish Journal of Biochemistry

Objective: The expressions of leptin and its receptor (ObR) have been observed in human gastric cancer (GC) tissue. Leptin can promote the proliferation of GC cells. However, the correlation between leptin and ObR expressions in GC and the role of gastric ObR protein levels in patients with GC is still unclear. This study aimed to evaluate the relationship between leptin, gastric ObR protein and soluble leptin receptor (sObR) levels and whether their possible role of indicator in GC. Methods: Serum leptin, gastric leptin and serum sObR concentrations were determined in 30 male patients with GC and 25 male dyspeptic subjects by enzym . . .e linked immunosorbent assay. We analysed the expression of gastric ObR levels in endoscopically obtained biopsy samples by using Western Blotting method. Results: Compared with controls, patients had lower serum leptin and higher gastric tissue leptin levels. sObR protein concentrations of patients were detected significantly higher, gastric ObR protein expression were lower than subjects in control group. Conclusion: Leptin in gastric cancerous region and sObR in circulation are overexpressed in GC. Their expressions are associated with malignancy. Decreased leptin levels, induces the sObR signal in circulation. This negative feedback regulation is also seen in gastric tissue: increased gastric tissue leptin levels inhibits gastric ObR protein expression. Thus,leptin and ObR may be important indicators in GC Daha fazlası Daha az

Asuman SAVAŞÇIHABEŞ

Makale/Derleme | 2015 | Radioengineering Journal

The support of high spectral efficiency MIMO spatial-multiplexing communication in OFDM-based WLAN systems conforming to IEEE 802.11n standard requires the design and use of compact antennas and arrays with low correlation ports. For this purpose, compact space-multimode diversity provisioning stacked circular multimode microstrip patch antenna arrays (SCP-ULA) are proposed in this paper and their performance in terms of spatial and modal correlations, ergodic spectral efficiencies as well as compactness with respect to antenna arrays formed of vertically-oriented center-fed dipole elements (DP-ULA) and dominantmode operating circul . . .ar microstrip patch antennas (CPULA) are presented. The lower spatial and modal correlations and the consequent higher spectral efficiency of SCP-ULA with ML detection over statistically-clustered Kronecker-based spatially-correlated NLOS Ricean fading channels with respect to DP-ULA and CPULA at significantly lower antenna and array sizes represents SCP-ULA as a promising solution for deployment in terminals, modems and access points of next-generation high-speed 802.11n MIMO-OFDM WLAN systems. Daha fazlası Daha az

Asuman SAVAŞÇIHABEŞ

Makale/Derleme | 2014 | Radioengineering Journal

The purpose of this paper is to compare the turbo-coded Orthogonal Frequency Division Multiplexing (OFDM) and turbo-coded Single Carrier Frequency Domain Equalization (SC-FDE) systems under the effects of Carrier Frequency Offset (CFO), Symbol Timing Offset (STO) and phase noise in wide-band Vogler-Hoffmeyer HF channel model. In mobile communication systems multipath propagation occurs. Therefore channel estimation and equalization is additionally necessary. Furthermore a nonideal local oscillator generally is misaligned with the operating frequency at the receiver. This causes carrier frequency offset. Hence in coded SC-FDE and cod . . .ed OFDM systems; a very efficient, low complex frequency domain channel estimation and equalization is implemented in this paper. Also Cyclic Prefix (CP) based synchronization synchronizes the clock and carrier frequency offset. The simulations show that non-ideal turbo-coded OFDM has better performance with greater diversity than non-ideal turbo-coded SC-FDE system in HF channel Daha fazlası Daha az

Asuman SAVAŞÇIHABEŞ

Bildiri | 2019 | INSAC Proceedings Book , pp.388 - 393

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2019 | 6. Uluslararası Multidisipliner Çalışmaları Kongresi, Multicongress2019 , pp.84 - 84

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2018 | II. Uluslararası Multidisipliner Çalışmaları Kongresi, MULTICONGRESS 2018 , pp.394 - 394

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2018 | 4th International Conf. on Engineering and Natural Science (ICENS 2018), , pp.531 - 531

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2018 | 4th International Conf. on Engineering and Natural Science (ICENS 2018) , pp.532 - 532

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2014 | International Conference on Electronics Communications and Networks (CECNET’14) , pp.67 - 72

Bildiri

Asuman SAVAŞÇIHABEŞ

Kitap | 2014 | IGI Global Publications, Encyclopedia of Information Science and Technology , pp.3517 - 3533

Kitap

Asuman SAVAŞÇIHABEŞ

Bildiri | 2018 | URSI 2018 , pp.260 - 262

Bildiri

Asuman SAVAŞÇIHABEŞ

Bildiri | 2016 | 3. Haberleşme Teknolojileri Çalıştayı , pp.1 - 4

Bu çalışmada MIMO-OFDM WLAN sistemlerin kompakt bindirilmiş dairesel mikroşerit anten dizinleri kullanılarak ortak gönderici/alıcı anten seçimi ile performans analizleri üzerinde çalışılmıştır. IEEE802.11n standardı OFDM WLAN sistemlerde yüksek-seviye modlar ile ışıma yapan mikroşerit antenler kullanmanın yanısıra, gönderici ve alıcıda anten seçim tekniği uygulandığında RF zincir sayısı azaltılarak erişilebilir sistem kapasitesi ve iletim hızı daha da arttırılabilmektedir. Bu çalışmada, alıcıda esnek iki-aşamalı seçim algoritması kullanılmış, göndericide ise alttaşıyıcı başına seçim algoritması kullanılmıştır. Ergodik spektral verim . . .lilik cinsinden anten seçimi uygulanarak sistem performansı incelenmiş ve anten seçimi yapılmayan sonuçlar ile karşılaştırmalı analizler sunulmuştur Daha fazlası Daha az