Symmetric and Asymmetric Effects of Exchange Rate Changes on Stock Prices in Fragile Five Economies: Analysis of the Global Crisis and Pandemic Period

Isil Erem Ceylan,Fatih Ceylan 세종대학교 경제통합연구소 2023 Journal of Economic Integration Vol.38 No.4

This study examined the symmetric and asymmetric effects of exchange rate changes on stock prices in the economies of India, Indonesia, Brazil, South Africa, and Turkey, collectively known as the "Fragile Five" due to their similar economic dynamics in light of the global financial crisis and pandemic period. The study uses monthly data from July 2000 to July 2022, and panel autoregressive distributive lag and panel nonlinear autoregressive distributive lag models to investigate the effects of exchange rate changes on stock prices in the Fragile Five economies. Prior to the global financial crisis, exchange rate changes have both long- and short-term asymmetric effects on stock prices in the Fragile Five economies. However, after the global financial crisis, exchange rate changes have both short- and long-term asymmetric and symmetric effects. Similarly, exchange rate changes also have asymmetric effects on stock prices during the COVID-19 period.

Comparison of light transmittance in different thicknesses of zirconia under various light curing units

Isil Cekic-Nagas,Ferhan Egilmez,Gulfem Ergun 대한치과보철학회 2012 The Journal of Advanced Prosthodontics Vol.4 No.2

PURPOSE The objective of this study was to compare the light transmittance of zirconia in different thicknesses using various light curing units. MATERIALS AND METHODS A total of 21 disc-shaped zirconia specimens (5 mm in diameter) in different thicknesses (0.3, 0.5 and 0.8 mm) were prepared. The light transmittance of the specimens under three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) was compared by using a hand-held radiometer. Statistical significance was determined using two-way ANOVA (α=.05). RESULTS ANOVA revealed that thickness of zirconia and light curing unit had significant effects on light transmittance (P<.001). CONCLUSION Greater thickness of zirconia results in lower light transmittance. Light-emitting diodes light-curing units might be considered as effective as Plasma arc light-curing units or more effective than Quartz-tungsten-halogen light-curing units for polymerization of the resin-based materials.

Development and validation of a HPLC method for the determination of benzo(a)pyrene in human breast milk

Isil Gazioglu,Serife Evrim Kepekci Tekkeli 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.2

A simple analytical procedure was developed for the quantitation of benzo(a)pyrene in human breast milk using solid phase extraction (SPE) combined with high performance liquid chromatography. Before the chromatographic process, SPE, including C18 functional groups in silicagel cartridges, was conducted for sample preparation. A C18 column (100×4.6 mm id, 3 μm particle size) was used with acetonitrile:water (80:20) as the mobile phase at a flow rate 1mL/min at 30oC. Fluorimetric detection was performed for excitation and emission at 290 and 406 nm, respectively. It was observed that the calibration curve was linear over the range of 0.5–80 ng/mL. The limit of detection and limit of quantitation were found to be 0.5 and 1.07 ng/mL, respectively. Intraday and interday relative standard deviation values were less than 5.15%. Moreover, the newly developed method provides a fast, simple, cost effective, and sensitive assay to detect an important carcinogen substance, benzo(a)pyrene, in human breast milk.

In vitro study of fracture strength of provisional crown materials

Isil Karaokutan,Gulsum Sayin,Ozlem Kara 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.1

PURPOSE The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37℃ for 24 hours, and then they were thermocycled (TC, 5000×, 5-55℃) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (α=.05). RESULTS Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique.

Giant Breast Involvement in Acute Lymphoblastic Leukemia: MRI Findings

Isil Basara,Sebnem Orguc 한국유방암학회 2012 Journal of breast cancer Vol.15 No.2

Breast metastases in cases of leukemia are rare. We aimed to report the conventional-advanced magnetic resonance imaging (MRI) findings of unilateral breast involvement of acute lymphoblastic leukemia (ALL) and review the literature. A 32-year-old woman was first diagnosed with ALL in treated in 2004. She did not continue the follow-up after 2008. She was presented with a giant, progressive right breast palpable mass in 2010. Mass,contralateral breast tissue were evaluated with MRI, diffusion weighted imaging and MR spectroscopy. With MRI findings, lesion was evaluated as malignant, tru-cut biopsy revealed recurrence of ALL. Lymphoma, malignant melanoma, rhabdomyosarcoma are most common tumors metastase to breast. Breast metastases of leukemia are rare and occur primarily in patients with acute myeloid leukemia. Secondary ALL breast involvement is uncommon. In a patient with malignancy, any enlarging breast mass, even with benign radiologic appearance, should be investigated carefully and metastasis should not be forgotten.

The Effect of Agoraphobia on Oxidative Stress in Panic Disorder

Isil Gogcegoz Gul,Rifat Karlidag,Birgul Elbozan Cumurcu,Yusuf Turkoz,Sukru Kartalci,A. Cemal Ozcan,M. Erman Erdemli 대한신경정신의학회 2013 PSYCHIATRY INVESTIGATION Vol.10 No.4

We aimed to investigate whether agoraphobia (A) in panic disorder (PD) has any effects on oxidative and anti-oxidative parameters. We measured total antioxidant capacity (TAC), paraoxonase (PON), arylesterase (ARE) antioxidant and malondialdehyde (MDA) oxidant levels using blood samples from a total of 31 PD patients with A, 22 PD patients without A and 53 control group subjects. There was a significant difference between the TAC, PON, ARE and MDA levels of the three groups consisting of PD with A, PD without A and the control group. The two-way comparison to clarify the group creating the difference showed that the TAC, PON, and ARE antioxidants were significantly lower in the PD with A group compared to the control group while the MDA oxidant was significantly higher. There was no significant difference between the PD without A and control groups for TAC, PON, ARE and MDA levels. We clearly demonstrated that the oxidative stress and damage to the anti-oxidative mechanism are significantly higher in the PD group with A. These findings suggest that oxidative/anti-oxidative mechanisms may play a more important role on the pathogenesis of PB with A.

ON LACUNARY STATISTICAL ϕ-CONVERGENCE FOR TRIPLE SEQUENCES OF SETS VIA IDEALS

Isil Acik Demirci,Mehmet Gurdal 한국전산응용수학회 2022 Journal of applied mathematics & informatics Vol.40 No.3

In the present paper, we introduce some new notions of Wijsman \mathcal{I}-statistical convergence with the use of Orlicz function, lacunary sequence and triple sequences of sets, and obtain some analogous results from the new definitions point of views.

Effect of surface treatment and luting agent type on shear bond strength of titanium to ceramic materials

Isil Karaokutan,Gulsum Sayin Ozel 대한치과보철학회 2022 The Journal of Advanced Prosthodontics Vol.14 No.2

PURPOSE. This study aimed to compare the effect of different surface treatments and luting agent types on the shear bond strength of two ceramics to commercially pure titanium (Cp Ti). MATERIALS AND METHODS. A total of 160 Cp Ti specimens were divided into 4 subgroups (n = 40) according to surface treatments received (control, 50 μm airborne-particle abrasion, 110 μm airborne-particle abrasion, and tribochemical coating). The cementation surfaces of titanium and all-ceramic specimens were treated with a universal primer. Two cubic all-ceramic discs (lithium disilicate ceramic (LDC) and zirconia-reinforced lithium silicate ceramic (ZLC)) were cemented to titanium using two types of resin-based luting agents: self-cure and dual-cure (n = 10). After cementation, all specimens were subjected to 5000 cycles of thermal aging. A shear bond strength (SBS) test was conducted, and the failure mode was determined using a scanning electron microscope. Data were analyzed using three-way ANOVA, and the Tukey-HSD test was used for post hoc comparisons (P < .05). RESULTS. Significant differences were found among the groups based on surface treatment, resin-based luting agent, and ceramic type (P < .05). Among the surface treatments, 50 μm air-abrasion showed the highest SBS, while the control group showed the lowest. SBS was higher for dual-cure resin-based luting agent than self-cure luting agent. ZLC showed better SBS values than LDC. CONCLUSION. The cementation of ZLC with dual-cure resin-based luting agent showed better bonding effectiveness to commercially pure titanium treated with 50 μm airborne-particle abrasion.

The supercapacitor performance of hierarchical porous activated carbon electrodes synthesised from demineralised (waste) cumin plant by microwave pretreatment

I. Isil Gurten Inal,Stuart M. Holmes,Emine Yagmur,Nurcan Ermumcu,Anthony Banford,Zeki Aktas 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

ctivated carbon (AC) was prepared from waste cumin utilising the chemical activation method. The cumin was separately washed with HCl and HF to remove minerals. The surface areas of AC of the acid washed samples (AC-HCl, AC-HF) were 1468 and 1472 m2/g, compared with 1361 m2/g for AC obtained directly from the precursor. Washing with the acids improved the supercapacitor performance through a significant decrease in the internal resistance of electrodes. The specific capacitances of electrodes using ACs prepared from acid washed samples (HCl and HF) were 127F/g and 155F/g at current density of 1.5 mA/cm2, compared with 117 F/g from the unwashed precursor.

Serotonin Expression in Lichen Planus Lesions and Its Relationship with Depression/Anxiety

( Gokce Isil Kurmus ),( Muzeyyen Gonul ),( Filiz Canpolat ),( Demet Yilmazer ),( Eylem Sahin Cankurtaran ) 대한피부과학회 2019 Annals of Dermatology Vol.31 No.2

Background: Psychological factors such as stress, depression, and anxiety have been documented to contribute to the development of lesions in lichen planus (LP). Objective: To evaluate the relationship between serotonin expression in LP lesions and depression/anxiety. Methods: Forty patients (22 females, 18 males) with LP and 20 healthy control subjects were included in this study. The severity of LP was assessed with the palmar method (using the measurement of affected body surface area [BSA]). The depression and anxiety scores were measured with Beck's depression inventory (BDI) and Beck's anxiety inventory (BAI). The expression of serotonin was determined via immunohistochemistry in LP lesions and in the control group skin using a monoclonal antibody to serotonin. Results: The skin biopsies of the LP patients had significantly higher levels of serotonin than those of the control subjects (p<0.001). In the LP patients, and there was a positive correlation between serotonin expression and LP severity (p=0.022). Based on the results from the BDI and BAI, there was a significant relationship between the severity of depression/anxiety and intensity of serotonin expression (p <0.001). Conclusion: Data from this study suggest that serotonin may have a possible role in the pathogenesis of LP. Further, the relationship between serotonin expression in acute cutaneous lesions and the depression/anxiety scores indicates that serotonin may be a mediator for the association of LP and depression/anxiety simultaneously. There is a need for more specific studies showing the expression of serotonin in the lichen planus to demonstrate the cause or effect. (Ann Dermatol 31(2) 146∼153, 2019)