Vibration analysis of a Timoshenko beam carrying 3D tip mass by using differential transform method

Kati, Hilal Doganay,Gokdag, Hakan Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.4

Dynamic behaviour of beam carrying masses has attracted attention of many researchers and engineers. Many studies on the analytical solution of beam with concentric tip mass have been published. However, there are limited works on vibration analysis of beam with an eccentric three dimensional object. In this case, bending and torsional deformations of beam are coupled due to the boundary conditions. Analytical solution of equations of motion of the system is complicated and lengthy. Therefore, in this study, Differential Transform Method (DTM) is applied to solve the relevant equations. First, the Timoshenko beam with 3D tip attachment whose centre of gravity is not coincident with beam end point is considered. The beam is assumed to undergo bending in two orthogonal planes and torsional deformation about beam axis. Using Hamilton's principle the equations of motion of the system along with the possible boundary conditions are derived. Later DTM is applied to obtain natural frequencies and mode shapes of the system. According to the relevant literature DTM has not been applied to such a system so far. Moreover, the problem is modelled by Ansys, the well-known finite element method, and impact test is applied to extract experimental modal data. Comparing DTM results with finite element and experimental results it is concluded that the proposed approach produces accurate results.

Effects of endodontic treatment on salivary levels of CGRP and substance P: a pilot study

Arslan, Hakan,Yildiz, Ezgi Doganay,Koseoglu, Serhat The Korean Academy of Conservative Dentistry 2020 Restorative Dentistry & Endodontics Vol.45 No.3

Objectives: The aim of this study was to evaluate the effects of endodontic treatment on levels of substance P (SP) and calcitonin gene-related peptide (CGRP) in the saliva of patients with symptomatic apical periodontitis. Materials and Methods: Twelve patients with mandibular molars with symptomatic apical periodontitis were enrolled in this study. An initial saliva sample was collected just before administration of anesthesia for root canal treatment, which was performed at the first visit. A second saliva sample was collected at a control visit 1 week after treatment. Salivary SP and CGRP levels were evaluated quantitatively using biochemical assays. The data were analyzed using Pearson correlation analysis, the paired samples t-test, and the Mann-Whitney U test (p = 0.05). Results: The postoperative salivary level of SP was significantly lower than the preoperative level (p = 0.005). However, the postoperative salivary level of CGRP was similar to the preoperative level (p = 0.932). Visual analog scale (VAS) scores of patients' subjective pain were found to be positively correlated with salivary levels of SP (r = 0.421; p = 0.040). No statistically significant correlations were observed between salivary levels of CGRP and VAS scores for patients' subjective percussion tenderness (p = 0.533) or VAS scores for patients' subjective pain (p = 0.459). Conclusions: According to the results of the present study, salivary SP levels may be used as an objective indicator in the diagnosis and assessment of the degree of pain in endodontic diseases.

Coexistence of Darier's Disease and Acrokeratosis Verruciformis of Hopf

Suleyman Piskin,Aslihan Saygin,Latife Doganay,Deniz Kircuval,Eylem Gurkan 연세대학교의과대학 2004 Yonsei medical journal Vol.45 No.5

Darier's disease and acrokeratosis verruciformis are inherited with the same pattern and they share similar clinical properties. We present a patient with both Darier's disease and acrokeratosis verruciformis. The patient had had brownish and skin-colored papules, initially on her face and neck, since the age of 25. Similar lesions had gradually spread to various parts of her body and lastly the dorsal aspect of her feet. On dermatological examination, brownish and skin-colored, 2 to 5mm, keratotic papules were observed on her face, neck, both axillae, inframammary regions, and dorsa of the hands and feet. The nail examination revealed “V” shaped notches and longitudinal ridges on the fingers of both hands. The biopsy taken from the neck showed typical findings for Darier's disease. The biopsy from the dorsa of the left foot revealed the distinctive structures of acrokeratosis verruciformis. In this article the clinical and histopathological findings of these diseases are reviewed based on our patient.

Role of a Risk of Malignancy Index in Clinical Approaches to Adnexal Masses

Simsek, Hakki Sencer,Tokmak, Aytekin,Ozgu, Emre,Doganay, Melike,Danisman, Nuri,Erkaya, Salim,Gungor, Tayfun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Objective: The aim of this study was to evaluate predictive role of risk of malignancy index in discriminating between benign and malignant adnexal masses preoperatively. Methods: This retrospective study was conducted with a total of 569 patients with adnexal masses/ovarian cysts managed surgically at our clinic between January 2006 and January 2012. Obtained data from patient files were age, gravidity, parity, menopause status, ultrasound findings and CA125 levels. For all patients ultrasound scans were performed. For the assessment of risk of malignancy index (RMI) Jacobs' model was used. Histopathologic results of all patients were recorded postoperatively. Malignancy status of the surgically removed adnexal mass was the gold standard. Results: Of the total masses, 245 (43.1%) were malignant, 316 (55.5%) were benign and 8 (1.4%) were borderline. The mean age of benign cases was lower than malign cases ($35.2{\pm}10.9$ versus $50.8{\pm}13.4$, p<0.001). Four hundred and five of them (71.2%) were in premenopausal period. Malignant tumors were more frequent in postmenopausal women (81% versus 29%, p<0.001). All ultrasound parameters of RMI were statistically significantly favorable for malignant masses. In our study ROC curve analysis for RMI provided maximum Youden index at level of 163.85. When we based on cutoff level for RMI as 163.85 sensitivity, specificity, PPV, NPV was calculated 74.7%, 96.2%, 94% and 82.6%, respectively. Conclusions: RMI was found to be a significant marker in preoperative evaluation and management of patients with an adnexal mass, and was useful for referring patients to tertiary care centers. Although utilization of RMI provides increased diagnostic accuracy in preoperative evaluation of patient with an adnexal mass, new diagnostic tools with higher sensitivity and specificity are needed to discriminate ovarian cancer from benign masses.

Roles of Sonography and Hysteroscopy in the Detection of Premalignant and Malignant Polyps in Women Presenting with Postmenopausal Bleeding and Thickened Endometrium

Cavkaytar, Sabri,Kokanali, Mahmut Kuntay,Ceran, Ufuk,Topcu, Hasan Onur,Sirvan, Levent,Doganay, Melike Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: To assess the role of sonographic endometrial thickness and hysteroscopic polyp size in predicting premalignant and malignant polyps in postmenopausal women. Materials and Methods: A total of 328 postmenopausal women with abnormal uterine bleeding and thickened endometrium underwent operative hysteroscopy due to detection of endometrial polyps were included in this retrospective study. Preoperative endometrial thickness measured by transvaginal ultrasonography and polyp size on hysteroscopy were noted. Hysteroscopic resection with histology was performed for endometrial polyps. Endometrial thickness and polyp size were evaluated on the basis of final diagnosis established by histologic examination. Receiver operator characteristic curves were calculated to assess the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of endometrial thickness and polyp size for detecting pemalignant and malignant polyps. Results: Premalignant and malignant polyps were identified in 26 (7.9%) of cases. Sonographic measurement showed a greater endometrial thickness in cases of premalignant and malignant polyps when compared to benign polyps. On surgical hysteroscopy, premalignant and malignant polyps were also larger. Endometrial thickness demonstrated a sensitivity of 53.8%, specificity of 85.8%, PPV of 24.6% and NPV of 95.6% at a cut-off limit of 11.5 mm with diagnostic accuracy of 83.2%. Polyp size has a diagnostic accuracy of 94.8% with a sensitivity of 92.3%, specificity of 95.0%, PPV of 61.5% and NPV of 99.3% at a cut-off point of 19.5mm. Conclusions: Endometrial thickness measured by transvaginal ultrasonography is not sufficient in predicting premalignant and malignant endometrial polyps in postmenopausal women with abnormal uterine bleeding and thickened endometrium. Polyp size on hysteroscopy is a more accurate parameter, because of better sensitivity and specificity. However, while polyp size ${\geq}19.5mm$ seems to have a great accuracy for predicting premalignancy and malignancy, histologic evaluation is still necessary to exclude premalignant and malignant polyps.

Comparison of Neutrophil/Lymphocyte and Platelet/Lymphocyte Ratios for Predicting Malignant Potential of Suspicious Ovarian Masses in Gynecology Practice

Topcu, Hasan Onur,Guzel, Ali Irfan,Ozer, Irfan,Kokanali, Mahmut Kuntay,Gokturk, Umut,Muftuoglu, Kamil Hakan,Doganay, Melike Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Purpose: To compare the diagnostic accuracy of the neutrophil/lymphocyte ratio (NLR) with the platelet/lymphocyte ratio (PLR) in predicting malignancy of pelvic masses which are pre-operatively malignant suspicious. Materials and Methods: In this retrospective study we evaluated the clinical features of patients with ovarian masses which had pre-operatively been considered suspicious for malignancy. The patients whose intraoperative frozen sections were malign were classified as the study group, while those who had benign masses were the control group. Data recorded were age of the patient, diameter of the mass, pre-operative serum Ca 125 levels, platelet count, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio. Results: There was statistically significantly difference between the groups in terms of age, diameter of the mass, serum Ca 125 levels, platelet number and platelet/lymphocyte ratio. Mean neutrophil/lymphocyte ratios showed no difference between the groups. ROC curve analysis showed that age, serum Ca 125 levels, platelet number and PLR were discriminative markers in predicting malignancy in adnexal masses. Conclusions: According to the current study, serum Ca 125 levels, pre-operative platelet number and PLR may be good prognostic factors, while NLR is an ineffective marker in predicting the malignant characteristics of a pelvic mass.

Bag-1L is a Stress-withstand Molecule Prevents the Downregulation of Mcl-1 and c-Raf Under Control of Heat Shock Proteins in Cisplatin Treated HeLa Cervix Cancer Cells

Ozfiliz, Pelin,Arisan, Elif Damla,Coker-Gurkan, Ajda,Obakan, Pinar,Eralp, Tugce Nur,Dinler-Doganay, Gizem,Palavan-Unsal, Narcin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Background: Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin-induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, $10{\mu}M$ Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

Sepsis and Meningitis due to Listeria Monocytogenes

Orhan Yildiz,Bilgehan Aygen,Duygu Esel,Uner Kayabas,Emine Alp,Bulent Sumerkan,Mehmet Doganay 연세대학교의과대학 2007 Yonsei medical journal Vol.48 No.3

Purpose: This study focused on the effect of immuno-compromising conditions on the clinical presentation of severe listerial infection. Patients and Methods: Nine human listeriosis cases seen from 1991-2002 were reviewed. All adult patients, from whose blood, peritoneal fluid or cerebrospinal fluid (CSF) the L. monocytogenes was isolated, were included in this retrospective study. Results: Listeriosis presented as primary sepsis with positive blood cultures in 5 cases and meningitis with positive CSF cultures in 4 cases. All of these patients had at least one underlying disease, most commonly, hematologic malignancy, diabetes mellitus, amyloidosis and hepatic cirrhosis; 55.6% had received immunosuppressive or corticosteroid therapy within a week before the onset of listeriosis. The patients were adults with a mean age of 60 years. Fever, night sweats, chills and lethargy were the most common symptoms; high temperature (>38℃), tachycardia, meningeal signs and poor conditions in general were the most common findings on admission. The mortality rate was 33.3% and was strictly associated with the severity of the underlying disease. Mortality differences were significant between sepsis (20%) and meningitis (50%) patients. Conclusion: Listeriosis as an uncommon infection in our region and that immuno- suppressive therapy is an important pre-disposing factor of listeriosis. Sepsis and meningitis were more common in this group of patients and had the highest case-fatality rate for food-borne illnesses.

Risk Factors for Endometrial Hyperplasia Concomitant Endometrial Polyps in Pre- and Post-menopausal Women

Topcu, Hasan Onur,Erkaya, Salim,Guzel, Ali Irfan,Kokanali, Mahmut Kuntay,Sarıkaya, Esma,Muftuoglu, Kamil Hakan,Doganay, Melike Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Purpose: To evaluate the risk factors for endometrial hyperplasia concomitant endometrial polyps in pre- and post-menopausal women. Materials and Methods: A total of 203 patients undergoing endometrial sampling before hysterectomy were evaluated in this retrospective study. Data recorded were age, gravidity, parity, body mass index (BMI: weight(kg)/$height(m)^2$), endometrial thickness (ET), menopausal status, presence of adenomyosis and diabetes mellitus. Results: Endometrial hyperplasia and polyps were detected in 13 patients. There were statistically significant differences in terms of age, menopausal status, morbid obesity and diabetes mellitus (p<0.005). Logistic regression demonstrated that menopausal status and presence of diabetes mellitus were independent risk factors. Conclusions: According to the current study; menopause and diabetes mellitus are strong risk factors for the presence of concomitant endometrial polyps and endometrial hyperplasia.