A Study of Reliable Bio-Telemetry, Efficient Powering and Electromagnetic Exposure in Implantable Neural Systems

Yuce and Jean-Michel Redouté,Ahmed I. AL-Kalbani,Mehmet R. Yuce 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.1

Purpose This paper explores the bio-telemetry, powering and electromagnetic exposure design concerns in implanted neural systems. Methods A class-E transmitter transfers PWM-ASK (Pulse-Width Modulated Amplitude-Shift Keying) modulated data signals to the brain implants at an optimal speed, while efficiently delivering sufficient power so as to keep the exposure of tissue to electromagnetic fields within tolerable limits. Results A case study design illustrates that using a PWMASK modulated class-E transmitter, switching at a 5 MHz carrier frequency and requiring a voltage supply of 5 V, the maximal achievable data rate is equal to 168 kbps. Furthermore,two possible transmitter coil designs are proposed: simulations show that the minimal specific absorption rate (SAR) value when comparing these coils to power brain implants is equal to 1.72 W/kg for a transmitted power of 1 W per coil. Conclusions This paper illustrates how the fundamental limits on the achievable PWM-ASK data transmission rate,as well as achievable bit error rate (BER) versus signal to noise ratio (SNR), can be improved using a Class-E transmitter design. Additionally, it has been shown which coil setups can be used so as deliver sufficient power to implants while keeping the exposure of tissue to electromagnetic fields at a minimum.

Local thin jacketing for the retrofitting of reinforced concrete columns

Yuce, Serkan Z.,Yuksel, Ercan,Bingol, Yilmaz,Taskin, Kivanc,Karadogan, H. Faruk Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.27 No.5

Two series of tests were conducted to investigate the behavior of local thin jacketing for the retrofitting of reinforced concrete (RC) columns. In the first series, four full-scale RC columns with a height of 400 cm and a 30 cm square cross-section were tested under constant axial load and reversed cyclic lateral displacements. The heavily damaged columns were retrofitted with local thin jacketing. Self-compacting concrete (SCC) was used in the production of 7.5 cm thick, four-sided jacketing. The height of the jacketing was 100 cm for one specimen and 200 cm for all others. In the second series, the retrofitted columns were retested with the same axial load and displacement history. The effectiveness of local thin jacketing in the retrofitting of RC columns was examined with respect to lateral strength, stiffness, inelastic load-deformation behavior and energy dissipation.

In Vitro Antimicrobial Effect of Satureja wiedemanniana Against Bacillus Species Isolated from Raw Meat Samples

Yuce, Nihal,Aslim, Belma,Ozdogan, Hakan The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.4

In this study a total of 30 raw meat samples obtained from Ankara, Turkey were screened for the presence of Bacillus species. Among the meat samples analyzed, the predominant species isolated was Bacillus circulans; other Bacillus species were identified as Bacillus firmus, Bacillus lentus, Bacillus megaterium, Bacillus licheniformis, Bacillus mycoides, Bacillus sphaericus, and Bacillus cereus. Minced meat samples were more contaminated with Bacillus species than sliced beef sample. From these samples, 242 Bacillus species isolates were obtained, which were investigated for proteolytic and lipolytic activity, associated with meat spoilage. Interestingly, some Bacillus strains produced the highest values of proteolytic/lipolytic activities. Nineteen Bacillus strains were selected among the 242 isolates according to their proteolytic/lipolytic activity with a clear zone diameter of ${\geq}6\;mm$. The essential oil of Satureja wiedemanniana (Lalem) Velen was also tested against these 19 Bacillus species that had proteolytic and lipolytic activity. The essential oil yield obtained from the aerial parts of the plant was 0.35% (vol/wt). The inhibition zones of the essential oil obtained against all the Bacillus species were in the range of 5.0.12.0 mm. The oil showed high antimicrobial activities against B. licheniformis M 6(26), M 11(16), and M 12(1) strains. B. licheniformis 12(1) showed high lipolytic activity (18.0 mm). Also, B. licheniformis M 6(26) and M 11(16) showed high proteolytic activity (16.0 and 14.0 mm). These results may suggest that an essential oil of S. wiedemanniana can be used as a natural preservative in meat against spoilage bacteria.

A Novel Grounded Inductor Realization Using a Minimum Number of Active and Passive Components

Erkan Yuce,Shahram Minaei,Oguzhan Cicekoglu 한국전자통신연구원 2005 ETRI Journal Vol.27 No.4

In this study, we present a new topology for realizing a grounded inductor employing only a single current conveyor, called a negative-type modified inverting second-generation current conveyor (MICCII-), and a minimum number of passive components, two resistors, and one capacitor. The non-ideality effects of the MICCII- on a simulated inductor are investigated. To demonstrate the performance of the presented inductance simulator, we use it to construct a third order Butterworth high-pass filter and a parallel resonant circuit. Simulation results are given to confirm the theoretical analysis.

The Effect of Cr doping on the Magnetic and Magnetocaloric Properties of MnCoGe Alloys

S. Yuce Emre 한국자기학회 2013 Journal of Magnetics Vol.18 No.4

The structural, magnetic and magnetocaloric properties of CoMn1-xCrxGe (x=0.05-0.125) have been investigated by using electron microscopy, x-ray diffraction, calorimetric and magnetic measurements. In this study, our aim is to justify the magnetocaloric effect by tuning the structural and magnetic transition temperature with Cr doping on CoMnGe pure system. The substitution of Cr for Mn leads to a decrease of both structural and magnetic transition temperatures. However, structural and magnetic transition temperatures do not close to each other. From magnetization measurement, we calculate that isothermal entropy change associated with magnetic transition can be as high as 3.82 J kg<SUP>-1</SUP>K<SUP>-1</SUP> at 302 K in a field of 7 T. Meanwhile, structural phase transition contribution to isothermal entropy change is calculated as 5.85 J kg<SUP>-1</SUP>K<SUP>-1</SUP> at 322 K for 7 T.

Identity Construction through Language: The Case of the Turkish Language Reform

Can Bahadır Yuce 숙명여자대학교 아시아여성연구원 2019 OMNES: The Journal of Multicultural Society Vol.9 No.2

Autologous blood injection to the temporomandibular joint: magnetic resonance imaging findings

Candirli, Celal,Yuce, Serdar,Cavus, Umut Yucel,Akin, Kayihan,Cakir, Banu Korean Academy of Oral and Maxillofacial Radiology 2012 Imaging Science in Dentistry Vol.42 No.1

Purpose : The aim of this study was to investigate the effect of the autologous blood injection (ABI) for chronic recurrent temporomandibular joint (TMJ) dislocation using magnetic resonance imaging (MRI). Materials and Methods : ABI was applied to 14 patients who had chronic recurrent TMJ dislocation. MRIs of the patients were taken and compared before and one month after the injection. Results : All of the patients had no dislocations of their TMJs on clinical examination one month after the injection. In the pre-injection, unilateral or bilateral TMJ dislocations were observed on MRIs in all patients. One month after the injection, TMJ dislocations were not observed in MRI evaluation of any patients. A significant structural change that caused by ABI was not observed. Conclusion : The procedure was easy to perform and it caused no foreign body reaction. However, it was unclear how the procedure prevented the dislocation.

Stimuli-responsive NO-generating Nanoparticles for Enhanced EPR Effect and Intratumoral Accumulation of Doxorubicin

아누 프,Yuce Li,박재형 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Targeted drug delivery and controlled drug release remain challenging. To address this challenge, we synthesized intracellular nitric oxide-generating nanoparticles (NO-NPs) for tumor site-specific generation of vasodilator NO to enhance NP accumulation in tumor tissue, i.e., improve their enhanced permeability and retention (EPR) effect. These NPs are self-assembled from amphiphilic copolymers of poly(ethylene glycol) and nitrated dextran, which possesses inherent NO-releasing properties in the reductive intracellular microenvironment. After systemic administration of NO-NPs, we quantitatively appraised the increased tumor blood flow and enhanced vascular permeability than that achieved without NO. Additionally, we prepared doxorubicin (DOX)-encapsulated NO-NPs and demonstrated substantial therapeutic efficacy over the control groups with improved intratumoral DOX accumulation. Overall, we anticipate NO-NPs being an EPR enhancer to achieve a better anticancer therapeutic efficiency.

A multi-institutional analysis of sequential versus ‘sandwich’ adjuvant chemotherapy and radiotherapy for stage IIIC endometrial carcinoma

Cem Onal,Sezin Yuce Sari,Berna Akkus Yildirim,Guler Yavas,Melis Gultekin,Ozan Cem Guler,Serap Akyurek,Ferah Yildiz 대한부인종양학회 2019 Journal of Gynecologic Oncology Vol.30 No.3

Objective: To analyze the outcomes of sequential or sandwich chemotherapy (ChT) and radiotherapy (RT) in patients with node-positive endometrial cancer (EC). Methods: Data from 4 centers were collected retrospectively for 179 patients with stage IIIC EC treated with postoperative RT and ChT (paclitaxel and carboplatin). Patients were either treated with 6 cycles of ChT followed by RT (sequential arm; 96 patients) or with 3 cycles of ChT, RT, and an additional 3 cycles of ChT (sandwich arm; 83 patients). Prognostic factors affecting overall survival (OS) and progression-free survival (PFS) were analyzed. Results: The 5-year OS and PFS rates were 64% and 59%, respectively, with a median followup of 41 months (range, 5–167 months). The 5-year OS rates were significantly higher in the sandwich than sequential arms (74% vs. 56%; p=0.03) and the difference for 5-year PFS rates was nearly significant (65% vs. 54%; p=0.05). In univariate analysis, treatment strategy, age, International Federation of Gynecology and Obstetrics (FIGO) stage, pathology, rate of myometrial invasion, and grade were prognostic factors for OS and PFS. In multivariate analysis, non-endometrioid histology, advanced FIGO stage, and adjuvant sequential ChT and RT were negative predictors for OS, whereas only non-endometrioid histology was a prognostic factor for PFS. Conclusion: Postoperative adjuvant ChT and RT for stage IIIC EC patients, either given sequentially or sandwiched, offers excellent clinical efficacy and acceptably low toxicity. Our data support the superiority of the sandwich regimen compared to the sequential strategy in stage IIIC EC patients for OS.

Treatment of Hepatic Fibrosis by Using Human Mesenchymal Stem Cell-derived Exosomes

Dat Bui Van,Yuce Li,박재형 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Mesenchymal stem cell (MSC) therapy has emerged as a potential treatment for chronic diseases due to its regenerative ability. However, it has significant limitations such as cell’s movement, changing into inappropriate cell types, or growth of tumors. In order to overcome these risks, a revolutionary cell-free therapy was developed to treat the chronic disease, particularly hepatic fibrosis, by using human adipose stem cell-derived exosomes (hADSC-exos). The hADSC-exos were isolated from conditioned media of ADSCs using tangential flow filtration (TFF) method, then were suspended in PBS and stored at –80 °C. After intravenous injected into the liver-fibrotic mice, hADSC-exos preferred to maintain inside the livers, especially in damaged liver tissue, notably suppressed fibro genic markers and finally restored hepatic functions. In conclusion, exosomes derived from hADSC have a dramatic potential to treat chronic hepatic fibrosis.