Middle Electrode in a Vertical Transistor Structure Using an Sn Layer by Thermal Evaporation

Gabriel Leonardo Nogueira,Maiza da Silva Ozório,Marcelo Marques da Silva,Rogério Miranda Morais,Neri Alves 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.3

We report a process for performing the middle electrode for a vertical field effect transistor (VOFET) by the evaporation ofa tin (Sn) layer. Bare aluminum oxide (Al2O3), obtained by anodization, and Al2O3covered with a polymethylmethacrylate(PMMA) layer were used as the gate dielectric. We measured the electrical resistance of Sn while the evaporation was carriedout to find the best condition to prepare the middle electrode, that is, good lateral conduction associated with openingsthat give permeability to the electric field in a vertical direction. This process showed that 55 nm Sn thick is suitable foruse in a VOFET, being easier to achieve optimal thickness when the Sn is evaporated onto PMMA than onto bare Al2O3. The addition of a PMMA layer on the Al2O3surface modifies the morphology of the Sn layer, resulting in a lowering of thethreshold voltage. The values of threshold voltage and electric field, VTH= − 8 V and ETH= 354.5 MV/m respectively, werecalculated using an Al2O3film 20 nm thick covered with a 14 nm PMMA layer as gate dielectric, while for bare Al2O3thesevalues were VTH= − 10 V and ETH= 500 MV/m.

Throughput and Delay Optimal Scheduling in Cognitive Radio Networks under Interference Temperature

Didem G¨oz¨upek,Fatih Alag¨oz 한국통신학회 2009 Journal of communications and networks Vol.11 No.2

The xed spectrum assignment policy in today's wireless networks leads to inefcient spectrum usage. Cognitive radio network is a new communication paradigm that enables the unlicensed users to opportunistically use the spatio-temporally unoccupied portions of the spectrum, and hence realizing a dynamic spectrum access (DSA) methodology. Interference temperature model proposed by Federal Communications Commission (FCC) permits the unlicensed users to utilize the licensed frequencies simultaneously with the primary users provided that they adhere to the interference temperature constraints. In this paper, we formulate two NP-hard optimal scheduling methods that meet the interference temperature constraints for cognitive radio networks. The rst one maximizes the network throughput, whereas the second one minimizes the scheduling delay. Furthermore, we also propose suboptimal schedulers with linear complexity, referred to as maximum frequency selection (MFS) and probabilistic frequency selection (PFS). We simulate the throughput and delay performance of the optimal as well as the suboptimal schedulers for varying number of cognitive nodes, number of primary neighbors for each cognitive node, and interference temperature limits for the frequencies. We also evaluate the performance of our proposed schedulers under both additive white gaussian noise (AWGN) channels and Gilbert- Elliot fading channels.

The clinical success of ART restorations and Hall technique in primary molars: a randomized 18-month follow-up study

Oz Esra,Kırzıoglu Zuhal,Kale Canan 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.2

Objectives The aim of the study was to evaluate the clinical and radiographic success of the Hall technique (HT) and atraumatic restorative treatment (ART) restorations using high-viscosity glass-ionomer cement for the management of occlusal carious lesions in primary molars. Materials and Methods This randomized clinical study observed 40 children (aged 5–6 years). For each child, one tooth was treated with HT and one with ART. The primary outcome measures for HT restorations were successful, minor, and major failure rates. Clinical evaluations of ART restorations were performed according to the modified United States Public Health Service criteria during 18-month follow-up. McNemar test was used for statistical analysis. Results Thirty of 40 (75%) participants returned for 18 months of follow-up. In the clinical evaluations of teeth that were treated with HT, the patients did not have complaints of pain or other symptoms, all crowns remained in the oral cavity, the gums were healthy, and the teeth were functional in all evaluations. At the end of the 18-month follow-up, the surface texture and marginal integrity criteria of ART restorations were recorded as 26.7% and 33.3%, respectively. In the radiographic evaluation of 30 patients treated with ART and HT, all restorations were considered successful. Conclusions The 18-month clinical and radiographic results after treatments applied to single-surface cavities in anxious children showed that both treatment methods were successful. Objectives The aim of the study was to evaluate the clinical and radiographic success of the Hall technique (HT) and atraumatic restorative treatment (ART) restorations using high-viscosity glass-ionomer cement for the management of occlusal carious lesions in primary molars. Materials and Methods This randomized clinical study observed 40 children (aged 5–6 years). For each child, one tooth was treated with HT and one with ART. The primary outcome measures for HT restorations were successful, minor, and major failure rates. Clinical evaluations of ART restorations were performed according to the modified United States Public Health Service criteria during 18-month follow-up. McNemar test was used for statistical analysis. Results Thirty of 40 (75%) participants returned for 18 months of follow-up. In the clinical evaluations of teeth that were treated with HT, the patients did not have complaints of pain or other symptoms, all crowns remained in the oral cavity, the gums were healthy, and the teeth were functional in all evaluations. At the end of the 18-month follow-up, the surface texture and marginal integrity criteria of ART restorations were recorded as 26.7% and 33.3%, respectively. In the radiographic evaluation of 30 patients treated with ART and HT, all restorations were considered successful. Conclusions The 18-month clinical and radiographic results after treatments applied to single-surface cavities in anxious children showed that both treatment methods were successful.

Effect of various bleaching treatments on shear bond strength of different universal adhesives and application modes

Oz, Fatma Dilsad,Kutuk, Zeynep Bilge The Korean Academy of Conservative Dentistry 2018 Restorative Dentistry & Endodontics Vol.43 No.2

Objectives: The aim of this in vitro study was to evaluate the bond strength of 2 universal adhesives used in different application modes to bleached enamel. Materials and Methods: Extracted 160 sound human incisors were used for the study. Teeth were divided into 4 treatment groups: No treatment, 35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide. After bleaching treatments, groups were divided into subgroups according to the adhesive systems used and application modes (n = 10): 1) Single Bond Universal, etch and rinse mode; 2) Single Bond Universal, self-etch mode; 3) Gluma Universal, etch and rinse mode; 4) Gluma Universal, self-etch mode. After adhesive procedures nanohybrid composite resin cylinders were bonded to the enamel surfaces. All specimens were subjected to shear bond strength (SBS) test after thermocycling. Data were analyzed using a 3-way analysis of variance (ANOVA) and Tukey post hoc test. Results: No significant difference were found among bleaching groups (35% hydrogen peroxide, 16% carbamid peroxide, 7.5% carbamid peroxide, and no treatment groups) in the mean SBS values. There was also no difference in SBS values between Single Bond Universal and Gluma Universal at same application modes, whereas self-etch mode showed significantly lower SBS values than etch and rinse mode (p < 0.05). Conclusions: The bonding performance of the universal adhesives was enhanced with the etch and rinse mode application to bleached enamel and non-bleached enamel.

Utility of Frozen Section Pathology with Endometrial Pre-Malignant Lesions

Oz, Murat,Ozgu, Emre,Korkmaz, Elmas,Bayramoglu, Hatice,Erkaya, Salim,Gungor, Tayfun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Aim: To determine utility of the frozen section (FS) in the operative management of endometrial pre-malignant lesions. Materials and Methods: We retrospectively analyzed patients who underwent abdominal hysterectomy with preoperative diagnosis of complex atypical endometrial hyperplasia (CAEH) and simple endometrial hyperplasia (SEH) between May 2007 and December 2013. Frozen and paraffin section (PS) results were compared. Sensitivity, specificity, the positive predictive value (PPV), the negative predictive value (NPV) and the accuracy in predicting EC on FS were evaluated with 95% confidence intervals (CIs) for each parameter. The correlation between FS and PS was calculated as an ${\kappa}$ coefficient. Results: Among 143 preoperatively diagnosed CAEH cases, 60 (42%) were malignant and 83 (58%) were benign in PS; and among 60 malignant cases diagnosed in PS, 43 (71%) were "malignant" in FS. Sensitivity, specificity, PPV and NPV for FS were 76%, 100%, 100% and 87.5%, respectively. Conclusions: We found that FS is reliable and applicable in the management of endometrial hyperplasias. It is important that the pathologist should be experienced because FS for endometrial pre-malignant lesions has significant inter-observer variability. The other conclusion is that patients with the diagnosis of EH, especially those who are postmenopausal, should undergo surgery where FS investigation is available.

In-plane vibrations of cracked slightly curved beams

Oz, H. Ridvan Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.36 No.6

In-plane vibrations of slightly curved beams having cracks are investigated numerically and experimentally. The curvature of the beam is circular and stays in the plane of vibration. Specimens made of steel with different lengths but with the same radius of curvature are used in the experiments. Cracks are opened using a hand saw having 0.4 mm thickness. Natural frequencies depending on location and depth of the cracks are determined using a Bruel & Kjaer 4366 type accelerometer. Then the beam is assumed as a Rayleigh type slightly curved beam in finite element method (FEM) including bending, extension and rotary inertia. A flexural rigidity equation given in literature for straight beams having a crack is used in the analysis. Frequencies are obtained numerically for different crack locations and depths. Experimental results are presented and compared with the numerical solutions. The natural frequencies are affected too much due to larger moments when the crack is around nodes. The effect can be neglected when it is at the location of maximum displacements. When the crack is close to the clamped end, the decrease in the frequencies in all modes is very high. The consistency of the results and validity of the equations are discussed.

Efficiency of Ultrasound and Ultrasound-Guided Fine Needle Aspiration Cytology in Preoperative Assessment of Axillary Lymph Node Metastases in Breast Cancer

Aysegul Oz,Figen Basaran Demirkazik,Meltem Gulsun Akpinar,Isıl Soygur,Atac Baykal,Sevgen Celik Onder,Aysegul Uner 한국유방암학회 2012 Journal of breast cancer Vol.15 No.2

Purpose: We performed this study to detect preoperative axillary metastases with ultrasound (US)-guided fine needle aspiration biopsy (FNAB), to eliminate the need for time-consuming and costly sentinel lymph node (SLN) scintigraphy and biopsy steps in the treatment of breast cancer patients, and in that of with suspicious US findings, and to evaluate the accuracy of preoperative US-guided FNAB for patients with suspicious lymph node metastases on US. Methods: Patients with a suspicious breast lump or histopathologically proven breast cancer underwent breast-axillary US. Increase in lymph node size, cortical thickening, non-hilar cortical flow, and hilar changes were evaluated with gray scale-color Doppler US. FNAB was performed if US results were suspicious for malignancy. Results: Thirty-eight axillary lymph nodes (ALN) underwent FNAB. ALN dissection, SLN scintigraphy, and biopsy steps were bypassed in 23 axillas with positive ALN FNAB (60.5%). The sensitivity of ALN FNAB was 88.46%; specificity and positive predictive value were 100%; and negative predictive value was 66.6% (inadequate cytology included; 76.7%, 100%, 100%, 53.3%, respectively). Asymmetrical cortical thickening, non-hilar cortical flow, and increase in hypoechogenity were only detected in metastatic nodes. Cortical thickening, and lymph node and breast mass size was higher in the metastatic group. Conclusion: By performing FNAB on suspicious lymph nodes, the routine, high-cost SLN scintigraphy and intraoperative gamma probe steps may be skipped, and axilla dissection can be performed directly. This leads to the elimination of the need for SLN investigation in more than half of the patients. The assessment of ALN metastases with preoperative US-guided FNAB is a cost-effective method with high specificity, that eliminates the need for costly and time-consuming SLN scintigraphy and biopsy steps, and helps in preoperative staging.

Photon Mass Energy Absorption Coefficients from 0.4 MeV to 10 MeV for Silicon, Carbon, Copper and Sodium Iodide

Hilmi Oz,Orhan Gurler,Ali Gultekin,O. Gundogdu,Sezai Yalcin 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.1

The absorption coefficients have been widely used for problems and applications involving dose calculations. Direct measurements of the coefficients are difficult, and theoretical computations are usually employed. In this paper, analytical equations are presented for determining the mass energy absorption coefficients for gamma rays with an incident energy range between 0.4 MeV and 10 MeV in silicon, carbon, copper and sodium iodide. The mass energy absorption coefficients for gamma rays were calculated, and the results obtained were compared with the values reported in the literature.

Antigenotoxicity, Cytotoxicity, and Apoptosis Induction by Apigenin, Bisabolol, and Protocatechuic Acid

Jaouad Anter,Magdalena Romero-Jiménez,Zahira Fernández-Bedmar,Myriam Villatoro-Pulido,Mohamed Analla,Ángeles Alonso-Moraga,Andrés Muñoz-Serrano 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.3

Medicinal plants represent an important resource in new drug research. Antioxidant properties of plants can help to scavenge reactive oxygen species. The objective of this work was to evaluate the genotoxic, antigenotoxic, tumoricidal, and apoptotic effect of some major phenols (apigenin, bisabolol, and protocatechuic acid) from two medicinal plants, Matricaria chamomilla and Uncaria tomentosa. The wing spot test of Drosophila melanogaster was used to evaluate the genotoxicity and antigenotoxicity of the three phenols. The human model of HL-60 leukemia cells was used for the assessment of the cytotoxic effect, growth, and cellular viability. The apoptotic effect was evaluated using a DNA fragmentation assay based on the formation of internucleosomal units. Protocatechuic acid (0.25 and 1 mM), apigenin (0.46 and 1.85 mM), and bisabolol (0.56 and 2.24 mM) did not exhibit any genotoxic effect. The three phenols showed an antigenotoxic effect against the hydrogen peroxide effect and also exhibited tumoricidal activity. Apigenin (2.24–35.96 mM) showed a lower 50% inhibitory concentration (0.75 and 3.87 mM for the trypan blue test and WST-8 colorimetric assay, respectively) than bisabolol and protocatechuic acid. These phenolics also induced apoptosis in HL-60 leukemia cells. This study suggests that the antioxidant activity of Chamomilla and Uncaria could be partially responsible of their beneficial activity.

Bounds for matching number of fundamental realizations according to new graph invariant Omega

MERT SINAN OZ,Ismail Naci CANGUL 장전수학회 2020 Proceedings of the Jangjeon mathematical society Vol.23 No.1

Matching number of a graph is one of the intensively studied areas in graph theory due to numerous applications of the matching and related notions. Recently, Delen and Cangul defined a new graph invariant denoted by which helps to determine several graph theoretical and combinatorial properties of the realizations of a given degree sequence. In this paper, using K2 deletion process, the maximum and minimum matching numbers of all so-called fundamental realizations of a given degree sequence.