Comparison of Efficacy and Safety between Transconjunctival 23-Gauge and Conventional 20-Gauge Vitrectomy Systems in Macular Surgery

( Tugba Goncu ),( Gokhan Gurelik ),( Berati Hasanreisoglu ) 대한안과학회 2012 Korean Journal of Ophthalmology Vol.26 No.5

Purpose: To compare the efficacy and safety of 23-gauge transconjunctival vitrectomy with the conventional 20-gauge method in idiopathic epiretinal membrane and macular hole surgery. Methods: Sixty-one consecutive patients undergoing vitrectomy for idiopathic epiretinal membrane and macular hole were recruited to either 20- or 23-gauge vitrectomy groups and prospectively evaluated. Surgical success rates, operating time, surgery-related complications, long-term visual outcomes, and postoperative ocular surface problems are compared in the two groups. Results: There were 31 eyes in the 20-gauge group and 33 eyes in the 23-gauge group. The macular hole closure rate after the first surgery was 83% and 90.9% in the 20-gauge and 23-gauge groups, respectively, with no significant difference between groups (p=0.59). The success rate for idiopathic epiretinal membranes cases was 100% in both groups. There was no statistically significant difference between overall surgical times (p=0.90). None of the patients in either group experienced postoperative complications of severe postoperative hypotony, vitreous hemorrhage or endophthalmitis, except one eye in the 20-gauge group, which was found to have retinal detachment. In both groups, statistically significant improvement in visual acuity was achieved 1-month postoperatively (p=0.002) and thereafter at all postoperative visits (p<0.05). The mean ocular surface scores were significantly lower in the 23-gauge group at all postoperative visits compared with the 20-gauge group scores (p=0.001). Conclusions: Transconjunctival 23-gauge vitrectomy appears to be as effective and safe as conventional 20-gauge vitrectomy in idiopathic epiretinal membrane and macular hole surgeries.

The effect of different micro-osteoperforation depths on the rate of orthodontic tooth movement

Tugba Haliloglu Ozkan,Selim Arici 대한치과교정학회 2021 대한치과교정학회지 Vol.51 No.3

Objective: This study aimed to identify the clinical effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement. Methods: Twenty-four patients requiring the removal of the upper first premolar teeth were selected and randomly divided into two groups. The control group participants did not undergo MOPs. Participants in the experimental group underwent three MOPs each at 4-mm (MOP-4) and 7-mm (MOP-7) depths, which were randomly and equally performed to either the left or right side distal to the canine. The retraction amount was measured on three-dimensional digital models on the 28th day of retraction. MOP-related pain was measured using a visual analog scale (VAS). Between-group statistical differences in the VAS scores were determined using an independent t-test and those in canine retraction were determined using analysis of variance and posthoc Tukey test. Results: No significant difference was found between the MOP- 4 (1.22 ± 0.29 mm/month) and MOP-7 (1.29 ± 0.31 mm/month) groups in terms of the canine retraction rate. Moreover, both the groups demonstrated a significantly higher canine movement than the control group (0.88 ± 0.19 mm/ month). MOPs did not significantly affect the mesialization of the posterior teeth (p > 0.05). Moreover, the pain scores in the MOP-4 and MOP-7 groups were similar and showed no statistically significant difference. Conclusions: Three MOPs with a depth of 4 mm can be performed as an effective method to increase the rate of tooth movement. However, three MOPs with depths of 4–7 mm does not additionally enhance tooth movement.

Thermal stress analysis around a cavity on a bimetal

Tugba Baytak,Osman Bulut 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.69 No.1

The plates made of two materials joined to each other having the different coefficient of thermal expansions are frequently encountered in the industrial applications. The stress analysis of these members under the effect of high-temperature variation has great importance in design. In this study, the stress analysis of the experimental model developed for the problem considered here was performed by the method of photothermoelasticity. The thermal strains were formed by the mechanical way and these were fixed by the strain freezing method. For the stress measurements, the method of slicing is applied which provides three-dimensional stress analysis. The analytical solution in the literature was compared with the related stress distribution obtained from the model. Moreover, the axisymmetric finite element model developed for the problem was solved by ABAQUS and the results obtained here compared with those of the experimental model and the analytical solution. As a result of this study, this experimental method and numerical model can be used for these type of thermal stress problems which have not been comprehensively analyzed yet.

An investigation on plan geometries of RC buildings: with or without projections in plan

Tugba Inan,Koray Korkmaz,Ismail H. Cagatay 사단법인 한국계산역학회 2012 Computers and Concrete, An International Journal Vol.9 No.6

The interaction of plan geometry and structural configuration, a determinative factor in the earthquake behavior of buildings, has become a serious issue in the building industry in Turkey due to the poor seismic performance of R/C buildings during the latest earthquake. Consequently, designing new buildings without structural irregularities against earthquake loads is proving to be more significant. This study focuses on the effects of plan geometries on earthquake performances of buildings. In that respect, structural irregularities in the plan are investigated in detail based on the Turkish Earthquake Code (TEC 2007). The study is based on five main parametric models and a total of 40 sub-models that are grouped according to their plan geometries with excessive projections such as L-shaped, H-shaped, T-shaped and U-shaped models. In addition to these, a square model without any projections is also generated. All models are designed to have the same storey gross area but with different number of storeys. Changes in the earthquake behavior of buildings were evaluated according to the number of storeys, the projection ratios and the symmetry conditions of each model. The analysis of each structural irregularity resulted in many findings, which were then assessed. The study demonstrates that the square model delivers the best earthquake performance owing to its regular plan geometry.

The effect of architectural form on the earthquake behavior of symmetric RC frame systems

Tugba Inan,Koray Korkmaz,Ismail H. Cagatay 사단법인 한국계산역학회 2014 Computers and Concrete, An International Journal Vol.13 No.2

In this study, structural irregularities in plan, which has a considerable effect on earthquake behavior of buildings, have been investigated in detail based on Turkish Earthquake Code 2007. The study consists of six main parametric models and a total of 144 sub-models that are grouped based on RC structural systems such as frame, frame + rigid core, frame with shear wall, and frame with shear wall + rigid core. All models are designed to have both symmetrical plan geometry and regular rigidity distribution. Changes in the earthquake behavior of buildings were evaluated according to the number of storeys, number of axes and the configuration of structural elements. Many findings are obtained and assessed as a result of the analysis for each structural irregularity. The study shows that structural irregularities can be observed in completely symmetric buildings in terms of plan geometry and rigidity distribution.

Solution-Processable transparent conducting electrodes via the self-assembly of silver nanowires for organic photovoltaic devices

Tugba Camic, B.,Jeong Shin, Hee,Hasan Aslan, M.,Basarir, Fevzihan,Choi, Hyosung Elsevier 2018 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.512 No.-

<P><B>Abstract</B></P> <P>Solution-processed transparent conducting electrodes (TCEs) were fabricated via the self-assembly deposition of silver nanowires (Ag NWs). Glass substrates modified with (3-aminopropyl)triethoxysilane (APTES) and (3-mercaptopropyl)trimethoxysilane (MPTES) were coated with Ag NWs for various deposition times, leading to three different Ag NWs samples (APTES-Ag NWs (PVP), MPTES-Ag NWs (PVP), and APTES-Ag NWs (COOH)). Controlling the deposition time produced Ag NWs monolayer thin films with different optical transmittance and sheet resistance. Post-annealing treatment improved their electrical conductivity. The Ag NWs films were successfully characterized using UV–Vis spectroscopy, field emission scanning electron microscopy, optical microscopy and four-point probe. Three Ag NWs films exhibited low sheet resistance of 4–19Ω/sq and high optical transmittance of 65–81% (at 550nm), which are comparable to those of commercial ITO electrode. We fabricated an organic photovoltaic device by using Ag NWs as the anode instead of ITO electrode, and optimized device with Ag NWs exhibited power conversion efficiency of 1.72%.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fabrication of a transparent conducting electrode based on graphene/silver nanowires via layer-by-layer method for organic photovoltaic devices

Tugba Camic, B.,Oytun, Faruk,Hasan Aslan, M.,Jeong Shin, Hee,Choi, Hyosung,Basarir, Fevzihan Academic Press 2017 Journal of Colloid and Interface Science Vol. No.

<P><B>Abstract</B></P> <P>A solution-processed transparent conducting electrode was fabricated via layer-by-layer (LBL) deposition of graphene oxide (GO) and silver nanowires (Ag NWs). First, graphite was oxidized with a modified Hummer’s method to obtain negatively-charged GO sheets, and Ag NWs were functionalized with cysteamine hydrochloride to acquire positively-charged silver nanowires. Oppositely-charged GO and Ag NWs were then sequentially coated on a 3-aminopropyltriethoxysilane modified glass substrate via LBL deposition, which provided highly controllable thin films in terms of optical transmittance and sheet resistance. Next, the reduction of GO sheets was performed to improve the electrical conductivity of the multilayer films. The resulting GO/Ag NWs multilayer was characterized by a UV–Vis spectrometer, field emission scanning electron microscope (FE-SEM), optical microscope (OM) and sheet resistance using a four-point probe method. The best result was achieved with a 2-bilayer film, resulting in a sheet resistance of 6.5Ω sq<SUP>−1</SUP> with an optical transmittance of 78.2% at 550nm, which values are comparable to those of commercial ITO electrodes. The device based on a 2-bilayer hybrid film exhibited the highest device efficiency of 1.30% among the devices with different number of graphene/Ag NW LBL depositions.</P> <P><B>Graphical abstract</B></P> <P>Highly transparent and conductive graphene/Ag NWs hybrid electrode has been successfully developed by using layer-by-layer method for organic photovoltaic cells as an alternative to conventional indium tin oxide electrode.</P> <P>[DISPLAY OMISSION]</P>

SOME REMARKS FOR λ-SPIRALLIKE FUNCTION OF COMPLEX ORDER AT THE BOUNDARY OF THE UNIT DISC

Akyel, Tugba Korean Mathematical Society 2021 대한수학회논문집 Vol.36 No.4

We consider a different version of Schwarz Lemma for λ-spirallike function of complex order at the boundary of the unit disc D. We estimate the modulus of the angular derivative of the function $\frac{zf^{\prime}(z)}{f(z)}$ from below for λ-spirallike function f(z) of complex order at the boundary of the unit disc D by taking into account the zeros of the function f(z)-z which are different from zero. We also estimate the same function with the second derivatives of the function f at the points z = 0 and z = z₀ ≠ 0. We show the sharpness of these estimates and present examples.

SOME REMARKS ON THE SUBORDINATION PRINCIPLE FOR ANALYTIC FUNCTIONS CONCERNED WITH ROGOSINSKI'S LEMMA

Akyel, Tugba The Kangwon-Kyungki Mathematical Society 2021 한국수학논문집 Vol.29 No.2

In this paper, we present a Schwarz lemma at the boundary for analytic functions at the unit disc, which generalizes classical Schwarz lemma for bounded analytic functions. For new inequalities, the results of Rogosinski's lemma, Subordination principle and Jack's lemma were used.

A New Fe (III)-Selective Membrane Electrode Based on Fe (II) Phthalocyanine

Ozer, Tugba,Isildak, Ibrahim The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.3

A new miniaturized all solid-state contact Fe (III)-selective PVC membrane electrode based on Fe (II) phthalocyanine as a neutral carrier was described. The effects of the membrane composition and foreign ions on the electrode performance was investigated. The best performance was obtained with a membrane containing 32% poly (vinyl chloride), 64% dioctylsebacate, 3% Fe (II) phthalocyanine, and 1% potassium tetrakis (p-chlorophenyl) borate. The electrode showed near Nernstian response of $26.04{\pm}0.95mV/decade$ over the wide linear concentration range $1.0{\times}10^{-6}$ to $1.0{\times}10^{-1}M$, and a very low limit of detection $1.8{\pm}0.5{\times}10^{-7}M$. The potentiometric response of the developed electrode was independent at pH 3.5-5.7. The lifetime of the electrode was approximately 3 months and the response time was very short (< 7 s). It exhibited excellent selectivity towards Fe (III) over various cations. The miniaturized all solid-state contact Fe (III)-selective membrane electrode was successfully applied as an indicator electrode for the potentiometric titration of $1.0{\times}10^{-3}M$ Fe (III) ions with a $1.0{\times}10^{-2}M$ EDTA and the direct determination of Fe (III) ions in real water samples.