Predictive Value of Malignancy Risk Indices for Ovarian Masses in Premenopausal and Postmenopausal Women

Ertas, Sinem,Vural, Fisun,Tufekci, Ertugrul Can,Ertas, Ahmet Candost,Kose, Gultekin,Aka, Nurettin Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: To evaluate the predictive role of a risk of malignancy index in discriminating between benign and malignant adnexal masses preoperatively. Materials and Methods: A total of 408 patients with adnexal masses managed surgically between January 2010 and February 2014 were included. The risk of malignancy indices (RMI) 1, 2, 3 and 4 were calculated using findings for ultrasonography, menopausal status, and CA125 levels. Histopathologic results were the end point. ROC analysis was used for the sensitivity and the specificity of the models. Results: Some 37.6 % of the cases were malignant in the postmenopausal group while 7.9 % were malignant in the premenopausal group. Pelvic pain was the most common complaint, and the majority of the cases were diagnosed at stage 3. The RMI 1, 2, 3 and 4 yielded percentage sensitivities of 76.1, 79.1, 76.1 and 76.1 and specificities of 91.5, 89.1, 90.6, 88.6, respectively. RMI 1 was the most reliable test in the general population according to AUC levels and Kappa statistics. From ROC analysis results of post/premenopausal women, the RMI 1 (cut off: 200) yielded sensitivities of 84.0/60.9 and specificities of 87.7/92.5. With RMI 2 they were 88.6/60.9 and 80.0/91.0, with RMI 3 84.0/60.9 and 87.7/91.8, and with RMI 4 (cut off:400) 81.8/47.8 and 83.6 /44.0. Although test performance of RMI methods were good in a general population and postmenopausal women, the RMI inter-agreement validity was only moderate or fair in premenopausal women. Conclusions: Our study confirms the effectiveness of RMI algorithms in postmenopausal women. However, more sensitive tests are needed for premenopausal women.

Simulation-based fatigue life assessment of a mercantile vessel

Ertas, Ahmet H.,Yilmaz, Ahmet F. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6

Despite the availability of other transport methods such as land and air transportations, marine transportation is the most preferred and widely used transportation method in the world because of its economical advantages. In service, ships experience cyclic loading. Hence, it can be said that fatigue fracture, which occurs due to cyclic loading, is one of the most critical failure modes for vessels. Accordingly, this makes fatigue failure prevention an important design requirement in naval architecture. In general, a ship structure contains many structural components. Because of this, structural modeling typically relies on Finite Element Analysis (FEA) techniques. It is possible to increase fatigue performance of the ship structures by using FEA in computer aided engineering environment. Even if literature papers as well as rules of classification societies are available to assess effect of fatigue cracks onto the whole ship structure, analytical studies are relatively scarce because of the difficulties of modeling the whole structure and obtaining reliable fatigue life predictions. As a consequence, the objective of this study is to improve fatigue strength of a mercantile vessel against fatigue loads via analytical method. For this purpose, the fatigue life of the mercantile vessel has been investigated. Two different type of fatigue assessment models, namely Coffin-Manson and Morrow Mean stress approaches, were used and the results were compared. In order to accurately determine the fatigue life of the ship, a nonlinear finite element analysis was conducted considering plastic deformations and residual stresses. The results of this study will provide the designer with some guidelines in designing mercantile vessels.

Design optimization of spot welded structures to attain maximum strength

Ahmet H. Ertas 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.19 No.4

This study presents design optimization of spot welded structures to attain maximum strength by using the Nelder-Mead (Simplex) method. It is the main idea of the algorithm that the simulation run is executed several times to satisfy predefined convergence criteria and every run uses the starting points of the previous configurations. The material and size of the sheet plates are the pre-assigned parameters which do not change in the optimization cycle. Locations of the spot welds, on the other hand, are chosen to be design variables. In order to calculate the objective function, which is the maximum equivalent stress, ANSYS, general purpose finite element analysis software, is used. To obtain global optimum locations of spot welds a methodology is proposed by modifying the Nelder-Mead (Simplex) method. The procedure is applied to a number of representative problems to demonstrate the validity and effectiveness of the proposed method. It is shown that it is possible to obtain the global optimum values without stacking local minimum ones by using proposed methodology.

Simulation-based fatigue life assessment of a mercantile vessel

Ahmet H. Ertas,Ahmet F. Yilmaz 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.6

Despite the availability of other transport methods such as land and air transportations, marine transportation is the most preferred and widely used transportation method in the world because of its economical advantages. In service, ships experience cyclic loading. Hence, it can be said that fatigue fracture, which occurs due to cyclic loading, is one of the most critical failure modes for vessels. Accordingly, this makes fatigue failure prevention an important design requirement in naval architecture. Ingeneral, a ship structure contains many structural components. Because of this, structural modeling typically relies on Finite Element Analysis (FEA) techniques. It is possible to increase fatigue performance of the ship structures by using FEA in computer aided engineering environment. Even if literature papers as well as rules of classification societies are available to assess effect of fatigue cracks onto the whole ship structure, analytical studies are relatively scarce because of the difficulties of modeling the whole structure and obtaining reliable fatigue life predictions. As a consequence, the objective of this study is to improve fatigue strength of a mercantile vessel against fatigue loads via analytical method. For this purpose, the fatigue lifeof the mercantile vessel has been investigated. Two different type of fatigue assessment models, namely Coffin-Manson and Morrow Mean stress approaches, were used and the results were compared. In order to accurately determine the fatigue life of the ship, a nonlinear finite element analysis was conducted considering plastic deformations and residual stresses. The results of this study will provide the designer with some guidelines in designing mercantile vessels.

An investigation of non-linear optimization methods on composite structures under vibration and buckling loads

Akbulut, Mustafa,Sarac, Abdulhamit,Ertas, Ahmet H. Techno-Press 2020 Advances in computational design Vol.5 No.3

In order to evaluate the performance of three heuristic optimization algorithms, namely, simulated annealing (SA), genetic algorithm (GA) and particle swarm optimization (PSO) for optimal stacking sequence of laminated composite plates with respect to critical buckling load and non-dimensional natural frequencies, a multi-objective optimization procedure is developed using the weighted summation method. Classical lamination theory and first order shear deformation theory are employed for critical buckling load and natural frequency computations respectively. The analytical critical buckling load and finite element calculation schemes for natural frequencies are validated through the results obtained from literature. The comparative study takes into consideration solution and computational time parameters of the three algorithms in the statistical evaluation scheme. The results indicate that particle swarm optimization (PSO) considerably outperforms the remaining two methods for the special problem considered in the study.

Ostial Coronary Stenosis and Severe Aortic Stenosis in a Patient With Familial Hypercholesterolemia

Hasan Kaya,Faruk Ertas,Zuhal Arıtürk Atılgan,Sinan Demirtas,Ahmet Çalıs¸kan 대한심장학회 2012 Korean Circulation Journal Vol.42 No.8

Dynamic Phase Transition and Multicritical Dynamic Phase Diagrams of The Kinetic Spin-2 Ising Model With Repulsive Biquadratic Coupling under a Time-dependent Oscilating External Field

Mustafa Keskin,Mehmet Ertas,Osman Canko 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4

We calculate the dynamic phase transition (DPT) temperatures and present the dynamic phase diagrams in the kinetic spin-2 Blume-Emery-Griffiths model with repulsive biquadratic coupling under the presence of a time-dependent oscillating external magnetic eld. First, we employ the Glauber transition rates to construct the set of mean-field dynamic equations. Then, we study the time variation of the average order parameters to nd the phase in the system. We also investigate the behavior of the dynamic order parameters to characterize the nature (continuous or discontinu- ous)of the transition and to obtain the DPT points. We present the dynamic phase diagrams in the plane of the reduced temperature versus magnetic field amplitude. The phase diagrams exhibit the ferrimagnetic, ferromagnetic -1, antiquadrupolar and disordered fundamen- tal phases. In addition to these fundamental phases, depending on the interaction parameters, we find ten coexisting or mixed phases composed of binary and ternary combinations of fundamental phases. The phase diagrams also display many special points, such as a dynamic tricritical point, a zero-temperature critical point, a critical end point, a double critical end point, a multicritical point, a triple point and a tetracritical point.

The Effect of Dietary Black Cumin Seeds (Nigella Sativa L.) on the Performance of Broilers

Guler, Talat,Dalkilic, B.,Ertas, O.N.,Ciftci, M. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.3

Three hundred and sixty sexed 3-day-old broiler chicks were divided randomly into six treatment groups (control, antibiotic and black cumin at four levels) of 60 birds each. Black cumin seeds at 0.5%, 1%, 2% or 3% and avilamycin at 10 mg/kgt were added to the basal diet and their effects determined on feed intake, daily live weight gain, feed conversion ratio and carcass characteristics. There were no significant differences in daily feed intake at 21 and 42 days (p>0.05). Average daily gain was significantly different between the treatments. The birds fed the diet containing 1% black cumin seeds and antibiotic were the highest average daily gain, followed by those the other treatment diets and negative control (p<0.05). From 1 to 42 days of age, feed conversion ratios were improved significantly by supplementation with 1% black cumin seeds and with antibiotic (p<0.05) by approximately 5% compared to the control group. Similarly, the highest cold carcass, thigh, breast, wing, neck and liver weights were observed in the 1% black cumin and antibiotic groups (p<0.05). Accordingly, 1% supplementation of black cumin seeds to diets could be considered as an alternative natural growth promoter for poultry instead of antibiotics.

Prognostic Significance of Retroperitoneal Lymphadenectomy, Preoperative Neutrophil Lymphocyte Ratio and Platelet Lymphocyte Ratio in Primary Fallopian Tube Carcinoma: A Multicenter Study

Kemal Gungorduk,Ibrahim E. Ertas,Aykut Ozdemir,Emrah Akkaya,Elcin Telli,Salih Taskin,Mehmet Gokcu,Ahmet Baris Guzel,Tufan Oge,Levent Akman,Tayfun Toptas,Ulas Solmaz,Askın Dogan,Mustafa Cosan Terek,Muz 대한암학회 2015 Cancer Research and Treatment Vol.47 No.3

Purpose The purpose of this study is to evaluate the prognostic role of preoperative neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) and the need for para-aortic lymphadectomy in patients with primary fallopian tube carcinoma (PFTC). Materials and Methods Ninety-one patients with a diagnosis of PFTC were identified through the gynecologic oncology service database of six academic centers. Clinicopathological, surgical, and complete blood count data were collected. Results In univariate analysis, advanced stage, suboptimal surgery, and NLR > 2.7 were significant prognostic factors for progression-free survival, whereas in multivariate analysis, only advanced stage and suboptimal surgery were significant. In addition, in univariate analysis, cancer antigen 125 ! 35 U/mL, ascites, advanced stage, suboptimal surgery, NLR > 2.7, PLR > 233.3, platelet count ! 400,000 cells/mm3, staging type, and histological subtype were significant prognostic factors for overall survival (OS); however, in multivariate analysis, only advanced stage, suboptimal surgery, NLR > 2.7, and staging type were significant. Inclusion of pelvic and para-aortic lymphadenectomy in surgery showed significant association with longer OS, with a mean and median OS of 42.0 months and 35.5 months (range, 22 to 78 months), respectively, vs. 33.5 months and 27.5 months (range, 14 to 76 months), respectively, for patients who underwent surgery without para-aortic lymphadenectomy (hazard ratio, 3.1; 95% confidence interval, 1.4 to 5.7; p=0.002). Conclusion NLR (in both univariate and multivariate analysis) and PLR (only in univariate analysis) were prognostic factors in PFTC. NLR and PLR are inexpensive and easy tests to perform. In addition, patients with PFTC who underwent bilateral pelvic and para-aortic lymphadenectomy had longer OS.

Adjuvant Treatment Modalities, Prognostic Predictors and Outcomes of Uterine Carcinosarcomas

Kemal Gungorduk,Aykut Ozdemir,Ibrahim E. Ertas,Mehmet Gokcu,Elcin Telli,Tufan Oge,Ahmet Sahbaz,Sevil Sayhan,Muzaffer Sanci,Mehmet Harma,Sinan Ozalp 대한암학회 2015 Cancer Research and Treatment Vol.47 No.2

Purpose The purpose of this study is to evaluate the clinicopathological characteristics, treatment,and prognosis of uterine carcinosarcoma (UC). Materials and MethodsA retrospective review of three cancer registry databases in Turkey was conducted foridentification of patients diagnosed with UC between January 1, 1996, and December 31,2012. We collected clinicopathological data in order to evaluate factors important in disease-free survival (DFS) and overall survival (OS). ResultsA total of 66 patients with UC with a median age of 65.0 years were included in the analysis. The median survival time of all patients was 37.5 months and the 5-year OS rate was 59.1%. In early stage patients (I-II) who received adjuvant chemotherapy (CT) with radiation therapy(RT), the median DFS and OS was 44 months and 55 months, respectively, compared to34.5 months and 36 months, respectively, in patients who received adjuvant RT or CT alone(hazard ratio [HR], 1.4; 95% confidence interval [CI], 0.7 to 3.1 for DFS; p=0.23 and HR,2.2; 95% CI, 0.9 to 5.3 for OS; p=0.03). In advanced stage patients (III-IV), the median DFSand OS of patients receiving adjuvant RT with CT was 25 months and 38 months, respectively,compared to 23.5 months and 24.5 months, respectively, in patients receivingadjuvant RT or CT alone (HR, 3.1; 95% CI, 0.6 to 16.0 for DFS; p=0.03); (HR, 3.3; 95% CI,0.7 to 15.0 for OS; p=0.01). In multivariate analysis, advanced International Federation ofGynecology and Obstetrics (FIGO) stage and suboptimal surgery showed significant associationwith poor OS. ConclusionIn patients with early or advanced stage UC, adjuvant CT with RT is associated with improvedDFS and OS, as compared to CT or RT alone.