Vibrations of a Box-Sectional Cantilever Timoshenko Beam with Multiple Cracks

Ahmet Can Altunışık,Fatih Yesevi Okur,Volkan Kahya 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.2

This paper considers a Timoshenko cantilever beam with box cross-section including multiple cracks. Under six damage scenarios, the problem is solved analytically by the transfer matrix method, and numerically by the fi nite element method. Results are validated by the experimental measurements with the aid of ambient vibration tests, that use Enhanced Frequency Domain Decomposition and Stochastic Subspace Identifi cation methods. Measured and calculated natural frequencies and mode shapes for undamaged and damaged beams are compared with each other. Modal assurance criterion and coordinated modal assurance criterion values are obtained from two set of measurements to establish the correlation between the measured and calculated mode shapes for the damage location identifi cation.

Eyelid Tumors: Clinical Data from an Eye Center in Ankara, Turkey

Gundogan, Fatih Cakir,Yolcu, Umit,Tas, Ahmet,Sahin, Omer Faruk,Uzun, Salih,Cermik, Hakan,Ozaydin, Sukru,Ilhan, Abdullah,Altun, Salih,Ozturk, Mustafa,Sahin, Fahri,Erdem, Uzeyir Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Introduction: The aim of the study was to explore the distribution of eyelid tumors in Ankara, the capital city of Turkey, from a histopathological point of view. Materials and Methods: Medical records of 1,502 patients who had eyelid surgery because of tumoral lesions were retrospectively reviewed after obtaining institutional review board approval. A total of 1,541 lesions with histopathologic diagnosis were included. Inflammatory tumoral lesions were excluded. The lesions were categorized into three groups according to the origin: epidermal, adnexal tumors and 'others', including melanocytic, neural and vascular lesions. Results: Of the total of 1,541, 908 lesions were epidermal in origin. Only 22 (1.5%) were malignant, and 6.0% was premalignant lesions such as actinic keratosis and Bowen's disease. Twenty-one of 22 malignant lesions were basal cell carcinoma. There was only one patient with squamous cell carcinoma and no sebaceous cell carcinoma. Among the benign tumors (92.5%), squamous papilloma was the most frequent (21.8% of all lesions). The other frequent lesions were nevus (17.6%), seborrheic keratosis (17.3%), hydrocystomas (10.6%), xanthelasma (7.6%) and epidermal cysts (7.2%). Conclusions: The results of this study are in accordance with published literature. The absence of sebaceous cell carcinomas needs to be stressed.

Investigation of Axial Load Capacity of (+)-Shaped Section BRBs with Friction and Frictionless

Oğuz Düğenci,Fatih Altun 한국강구조학회 2023 International Journal of Steel Structures Vol.23 No.5

This study presents designing the conventional braces with (+) shaped cross-sections as buckling restrained braces (BRB) with friction and frictionless surfaces without a gap. In this context, cyclic axial loading tests were carried out on seven braces members (one was a reference brace and the others had an outer casing and mortar). In addition, numerical models of the specimens were created and analysed with ANSYS. The core brace members were confined by two different types of steel profiles (SHS and CHS series) for the design. Each series consisted of three specimens separately. The specimen of reference and core of BRBs was a (+)-shaped section brace. In the experimental study, while a natural friction surface was preserved between the brace-steel outer casing in the first specimen of the series, a frictionless surface was created in the second. In the third specimen of the series, the gap between the core-steel outer casing was filled with mortar. The performance of the specimens was evaluated depending on the axial load capacity, hysteric behaviour and ductility. Compared to the reference in the unfilled specimens, the tensile strength increased by 3.4–6.0%, while this increase was 22.4–32.0% in the mortar-filled specimens. When the axial load capacities were considered, the increases were 268.3 and 249.8% in the mortar-filled specimens. On the other hand, mortar-filled specimens reached the highest axial load capacity. While there is an increase in energy ductility, it might be said that there is a decrease in general ductility in all specimens because of early failures. It had been observed that the lateral-torsional buckling effect of the (+) section has a direct effect on the failure mechanism.

Effect of etoricoxib on experimental oxidative testicular ischemia–reperfusion damage in rats induced with torsion– detorsion

Turgut Yapanoglu,Fatih Ozkaya,Ali Haydar Yilmaz,Renad Mammadov,Ferda Keskin Cimen,Erkan Hirik,Durdu Altuner 대한약리학회 2017 The Korean Journal of Physiology & Pharmacology Vol.21 No.5

Etoricoxib features antioxidant and anti-inflammatory properties concomitantly, suggesting that it may be beneficial in testicular ischemia reperfusion (I/R) damage. Our aim is to investigate the effects of etoricoxib on testicular I/R damage induced with torsion-detorsion (TD). The etoricoxib + torsion-detorsion (ETD) groups of animals were given etoricoxib in 50 and 100 mg/kg of body weight (ETD- 50 and ETD-100), while the testes torsion-detorsion (TTD) and sham operation rat group (SOG) animals were given single oral doses of distilled water as a solvent. TTD, ETD-50 and ETD-100 groups were subjected to 720o degrees torsion for four hours, and detorsion for four hours. The SOG group was not subjected to this procedure. Biochemical, gene expression and histopathological analyses were carried out on the testicular tissues. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) were significantly higher, and the levels of total glutathione (tGSH) and glutathione reductase (GSHRd) were significantly lower in the TTD group, compared to the ETD-50, ETD-100 and SOG groups. Etoricoxib at a dose of 100 mg/kg better prevented I/R damage than the 50 mg/kg dose. Etoricoxib may be useful in clinical practice in the reduction of I/ R damage on testes caused by torsion-detorsion.

Effect of etoricoxib on experimental oxidative testicular ischemia-reperfusion damage in rats induced with torsion-detorsion

Yapanoglu, Turgut,Ozkaya, Fatih,Yilmaz, Ali Haydar,Mammadov, Renad,Cimen, Ferda Keskin,Hirik, Erkan,Altuner, Durdu The Korean Society of Pharmacology 2017 The Korean Journal of Physiology & Pharmacology Vol.21 No.5

Etoricoxib features antioxidant and anti-inflammatory properties concomitantly, suggesting that it may be beneficial in testicular ischemia reperfusion (I/R) damage. Our aim is to investigate the effects of etoricoxib on testicular I/R damage induced with torsion-detorsion (TD). The etoricoxib + torsion-detorsion (ETD) groups of animals were given etoricoxib in 50 and 100 mg/kg of body weight (ETD-50 and ETD-100), while the testes torsion-detorsion (TTD) and sham operation rat group (SOG) animals were given single oral doses of distilled water as a solvent. TTD, ETD-50 and ETD-100 groups were subjected to $720^{\circ}$ degrees torsion for four hours, and detorsion for four hours. The SOG group was not subjected to this procedure. Biochemical, gene expression and histopathological analyses were carried out on the testicular tissues. The levels of malondialdehyde (MDA), myeloperoxidase (MPO), interleukin-1 beta ($IL-1{\beta}$) and tumor necrosis factor alpha ($TNF-{\alpha}$) were significantly higher, and the levels of total glutathione (tGSH) and glutathione reductase (GSHRd) were significantly lower in the TTD group, compared to the ETD-50, ETD-100 and SOG groups. Etoricoxib at a dose of 100 mg/kg better prevented I/R damage than the 50 mg/kg dose. Etoricoxib may be useful in clinical practice in the reduction of I/R damage on testes caused by torsion-detorsion.

The Association between Subclinical Hypothyroidism and Epicardial Adipose Tissue Thickness

Erdal Belen,Aleks Degirmencioglu,Ertugrul Zencirci,Fatih Fahri Tipi,Özgür Altun,Gültekin Karakus,Ays¸en Helvacı,Aycan Esen Zencirci,Ezgi Kalaycıoglu 대한심장학회 2015 Korean Circulation Journal Vol.45 No.3

Background and Objectives: Subclinical hypothyroidism (SH) is considered to be a potential risk factor for cardiovascular disease. Epicardial adipose tissue (EAT) thickness is also closely related to cardiovascular disorders. The aim of this study was to evaluate whether SH is associated with higher EAT thickness. Subjects and Methods: Fifty-one consecutive patients with SH and 51 healthy control subjects were prospectively enrolled into this trial. Thyroid hormone levels, lipid parameters, body mass index, waist and neck circumference, and EAT thickness measured by echocardiography were recorded in all subjects. Results: Mean EAT thickness was increased in the SH group compared to the control group (6.7±1.4 mm vs. 4.7±1.2 mm, p<0.001). EAT thickness was shown to be correlated with thyroid stimulating hormone level (r=0.303, p=0.002). Multivariate logistic regression analysis revealed that EAT thickness was independently associated with SH {odds ratio (OR): 3.87, 95% confidence interval (CI): 1.92–7.78, p< 0.001; OR: 3.80, 95% CI: 2.18–6.62, p<0.001}. Conclusion: Epicardial adipose tissue thickness is increased in patients with SH compared to control subjects, and this increase in EAT thickness may be associated with the potential cardiovascular adverse effects of SH.

A comparative investigation of biochemical and histopathological effects of thiamine and thiamine pyrophosphate on ischemia– reperfusion induced oxidative damage in rat ovarian tissue

Ismail Demiryilmaz,Ebru Sener,Nihal Cetin,Durdu Altuner,Fatih Akcay,Halis Suleyman 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.9

In this study, the biochemical and histopathologicaleffects of thiamine and thiamine pyrophosphate onischemia–reperfusion induced oxidative damage in ratovarian tissue were investigated. Animals were divided intofour groups of six rat each, ovarian ischemia–reperfusion(IR), 25 mg/kg thiamine ? ovarian ischemia–reperfusion(TIR), 25 mg/kg thiamine pyrophosphate ? ovarian ischemia–reperfusion (TPIR) and Sham group (SG). The resultsof the biochemical experiments have shown that the ratovarian tissue with thiamine treatment, the level of MDA,GSH and the 8-hydroxyguanine are almost the same as theIR group; while in the group with thiamine pyrophosphatetreatment, the level of MDA, GSH and the 8-hydroxyguanineare almost the same as the SG. Ovarian tissue of rats inthe IR group were congested and dilated vessels, edema,hemorrhage, necrotic and apoptotic cells. In this group, themigration and the adhesion of the polymorphonuclear leucocytesto the endothelium were observed. Both ovaries inTPIR group, there was no difference according to the SG. Histopathology of ovarian tissues in the TIR group wasalmost the same with the IR group. Our results indicate thatthiamine pyrophosphate significantly prevents the ischemia–reperfusion induced oxidative damage in ovarian tissue,whereas thiamine has no effect. In conclusion, we havefound that thiamine pyrophosphate prevents oxidativedamage due to ischemia–reperfusion injury, whereasthiamine does not have this effect. Furthermore, we haveconfirmed that the results of our biochemical analyses are inconcordance with the histopathological findings.

Increased Serum G Protein-coupled Estrogen Receptor 1 Levels and Its Diagnostic Value in Drug Naïve Patients with Major Depressive Disorder

Ebru Findikli,Ergül Belge Kurutas,Mehmet Akif Camkurt,Mehmet Fatih Karaaslan,Filiz Izci,Hüseyin Avni Fındıklı,Selçuk Kardaş,Berat Dag,Hatice Altun 대한정신약물학회 2017 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.15 No.4

Objective: The facts that depression is more prevalent in females than in males and females are exposed to depression more commonly during certain hormonal fluctuating periods indicate the role of sex hormones in physiopathology. Estrogen acts over estrogen receptors alpha and beta and recently identified G protein-coupled estrogen receptor 1 (GPER1). The present study aimed, for the first time, to evaluate serum GPER1 levels in drug-naïve major depressive disorder (MDD) patients. Methods: The study included 56 newly diagnosed drug-naïve MDD patients aged between 18 and 50 years and 42 age- and gender-matched healthy volunteers. Medical history was obtained and physical examinations, laboratory tests, and the Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A) were performed. The serum GPER1 levels were measured. Results: The HAM-D score was significantly higher in the MDD patients than in the controls. The GPER1 level was significantly higher in the MDD patients than in the controls. A positive correlation was found with GPER1 levels and depression scores. The receiver operating characteristic analysis revealed sensitivity, specificity, positive predictive value, and negative predictive value as 82.1%, 90.5%, 92.0%, and 79.2%, respectively, for the presence of depression, when the serum GPER1 value was ≥0.16. Conclusion: This study demonstrated significantly higher serum GPER1 levels in the MDD patients than in the controls, a positive correlation was found between GPER1 levels and depression scores and serum GPER1 level was valuable in predicting the presence of depression.