Yazar "Isik I." seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • Küçük Resim Yok
    Öğe
    Biophysical Model for Signal-Embedded Droplet Soaking into 2D Cell Culture
    (Association for Computing Machinery, Inc, 2023) Isik I.; Arjmandi H.; Corre C.; Noel A.
    Using agar plates hosting a 2D cell population stimulated with signaling molecules is crucial for experiments such as gene regulation and drug discovery in a wide range of biological studies. In this paper, a biophysical model is proposed that incorporates droplet soaking, diffusion of molecules within agar, cell growth over an agar surface, and absorption of signaling molecules by cells. The proposed model describes the channel response and provides valuable insights for designing experiments more efficiently and accurately. The molecule release rate due to droplet soaking into agar, which is characterized and modeled as the source term for the diffusion model, is derived. Furthermore, cell growth is considered over the surface, which dictates the dynamics of signaling molecule reactions and leads to a variable boundary condition. As a case study, genetically-modified E. coli bacteria are spread over the surface of agar and Isopropyl-beta-D thiogalactopyranoside (IPTG) is considered as a signaling molecule. IPTG droplets are dropped onto the bacteria-covered agar surface. The parameters for the IPTG molecule release rate as a diffusion source into the agar are estimated from this experiment. Then, a particle-based simulator is used to obtain the spatio-temporal profile of the signaling molecules received by the surface bacteria. The results indicate that the number of molecules reacting with or absorbed by bacteria at different locations on the surface could be widely different, which highlights the importance of taking this variation into account for biological inferences. © 2023 Owner/Author.
  • Küçük Resim Yok
    Öğe
    THE EFFECT OF CRYSTAL STRUCTURE AND METAL ELECTRODES ON GAS DETECTION IN TiO2 NANOTUBES H2 SENSORS
    (International Association for Hydrogen Energy, IAHE, 2022) Tasyurek L.B.; Isik E.; Isik I.; Kilinc N.
    In this study, the effects of various metal electrodes and various crystal structures on hydrogen (H2) gas sensors based on titanium dioxide (TiO2) nanotubes were investigated. For the production of TiO2 nanotubes, anodization method consisting of an electrolyte containing 0.5wt% NH4F in 85% pure glycerol solution was applied. Scanning electron microscope (SEM) images of the obtained TiO2 nanotubes were examined. In order to see the effect of different crystal structures of TiO2, amorphous, anatase and rutile phases were obtained by annealing of samples. Each of the Ti/TiO2 nanotubes/metal (Pd, Pt, Au, and Ag) gas sensors, obtained by coating with palladium (Pd), platinum (Pt), gold (Au) and silver (Ag) electrodes, was tested at room temperature at 1% H2 concentration depending on three different phases. © 2022 Proceedings of WHEC 2022 - 23rd World Hydrogen Energy Conference: Bridging Continents by H2. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Evaluation of Eyelid, Angle, and Anterior Segment Parameters Using Scheimpflug Camera and Topography System in Obstructive Sleep Apnea Syndrome
    (Kare Publishing, 2023) Isik I.; Yazgan S.; Erboy F.; Dogan M.
    Objectives: The purpose of the study was to investigate the eyelid hyperlaxity, anterior segment, and corneal topographic parameters in patients with obstructive sleep apnea syndrome (OSAS) using Scheimpflug camera and topography system. Methods: In this prospective and cross-sectional clinical study, 32 eyes of 32 patients with OSAS and thirty-two eyes of 32 healthy subjects were evaluated. The participants with OSAS were selected from those with an apnea-hypopnea index ? 15. The minimum corneal thickness (ThkMin), apical corneal thickness (ACT), central corneal thickness (CCT), pupillary diameter (PD), aqueous depth (AD), aqueous volume (AV), anterior chamber angle (ACA), horizontal anterior chamber diameter (HACD), corneal volume (CV), simulated K readings (sim-K), front and back corneal keratometric values at 3 mm, RMS/A values, highest point of ectasia on the anterior and posterior corneal surface (KVf, KVb), symmetry indices and keratoconus measurements were taken by combined Scheimpflug-Placido corneal topography and compared with healthy subjects. Upper eyelid hyperlaxity (UEH) and floppy eyelid syndrome were also evaluated. Results: There were no statistically significant difference between groups in terms of age, gender, PD, ACT, CV, HACD, simK readings, front and back keratometric values, RMS/A-KVf and KVb values, symmetry indices, and keratoconus measurements (p>0.05). ThkMin, CCT, AD, AV, and ACA values were significantly higher in OSAS group compared to the control (p<0.05). UEH was detected in two cases in the control group (6.3%) and in 13 cases in the OSAS group (40.6%) and the difference was significant (p<0.001). Conclusion: The anterior chamber depth, ACA, AV, CCT, and UEH increase in OSAS. These ocular morphological changes occurring in OSAS may explain why these patients prones to normotensive glaucoma. © Issues in Information Systems.All rights reserved
  • Küçük Resim Yok
    Öğe
    A preliminary investigation of receiver models in molecular communication via diffusion
    (Institute of Electrical and Electronics Engineers Inc., 2017) Isik I.; Yilmaz H.B.; Tagluk M.E.
    Molecular Communication (MC) is a new multidisciplinary subject concerning medicine, biology, and communication engineering. MC concept is introduced for modeling of communication of nano/micro scale devices. In MC systems, chemical signals carrying information in gaseous or liquid media are used. Similar to other communication systems, in MC sending information from transmitter to receiver with minimum error is one of the most important goals. In MC systems due to physical characteristics of medium, higher rates of inter symbol interference (ISI) and noise increase error probability. Figures of receiver mechanisms and signal detection techniques are therefore the main factors to be tuned for decreasing error probability. In this view, so far, many receiver models such as reversible adsorption and desorption (A&D), protrusion method, ligand receptor, and linear catalytic or CAT receiver models have been introduced. In this study, these models and the results obtained through their implementation are investigated and briefly reviewed. © 2017 IEEE.