Numerical determination of crack width for reinforced concrete deep beams

Aydin Demir,Naci Caglar 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.25 No.3

In the study, a new, simple and alternative formula is proposed to calculate numerically crack widths of concrete on a finite element (FE) model. By considering more general tension softening behavior of concrete, the proposed expression is derived irrespective of any tension softening model given in the literature or design codes. The test results of six reinforced concrete (RC) deep beams having different geometrical and material properties selected from a recent existing experimental study of the authors are used to verify the accuracy and reliability of the proposed formula and the created numerical FE models of the specimens. Moreover, the crack width results obtained from the FE models are compared with the test results to see the performance of the proposed formula. The results of the study demonstrate that the proposed formula gives very accurate results in a comparison with the test results. The ratios of errors on the results stay commonly at an acceptable level as well. Consequently, the proposed formula is quite simple, unique, and robust to determine crack widths of RC deep beams on an FE model.

Effects of Distant Reiki On Pain, Anxiety and Fatigue in Oncology Patients in Turkey: A Pilot Study

Demir, Melike,Can, Gulbeyaz,Kelam, Ayhan,Aydiner, Aydin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

Background: Fatigue, stress and pain are common symptoms among cancer patients, affecting the quality of life. The purpose of the present study was to determine the effect of distant Reiki on pain, anxiety and fatigue in oncology patients. Materials and Methods: Participants in the control group received usual medical and nursing care during their stay. The intervention group received usual care plus five distant Reiki sessions, one each night for 30 min. A face to face interview was performed and patient personal and illness related characteristics were evaluated using the Patient Characteristics form. Pain, stress and fatigue were evaluated according to a numeric rating scale. Results: The experimental group was predominantly composed of women (71.4%), married individuals (40%), and primary school graduates (40%). The control group was predominantly male (72.7%), married (60%), and primary school graduates (60%). The control group demonstrated greater levels of pain (p=0.002), stress (p=0.001) and fatigue (p=0.001). The Reiki group pain score (p <0.0001), stress score (p <0.001) and fatigue score were also significantly lower. Conclusions: The results of this study indicate that Reiki may d ecreasepain, anxiety and fatigue in oncology patients.

Progressive collapse resistance of low and mid-rise RC mercantile buildings subjected to a column failure

Aydin Demir 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.4

This study aimed to evaluate the progressive collapse potential of buildings designed using conventional design codes for the merchant occupancy classification and subjected to a sudden column failure. For this purpose, three reinforced concrete buildings having different story numbers were designed according to the seismic design recommendations of TSCB- 2019. Later on, the buildings were analyzed using the GSA-2016 and UFC 4-023-03 to observe their progressive collapse responses. Three columns were removed independently in the structures from different locations. Nonlinear dynamic analysis method for the alternate path direct design approach was implemented for the design evaluation. The plasticity of the structural members was simulated by using nonlinear fiber hinges. The moment, axial, and shear force interaction on the hinges was considered by the Modified Compression Field Theory. Moreover, an existing experimental study investigating the progressive collapse behavior of reinforced concrete structures was used to observe the validation of nonlinear fiber hinges and the applied analysis methodology. The study results deduce that a limited local collapse disproportionately more extensive than the initial failure was experienced on the buildings designed according to TSCB-2019. The mercantile structures designed according to current seismic codes require additional direct design considerations to improve their progressive collapse resistance against the risk of a sudden column loss.

THE SOURCE OF SEMIPRIMENESS OF RINGS

Aydin, Neset,Demir, Cagri,Camci, Didem Karalarlioglu Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.4

Let R be an associative ring. We define a subset $S_R$ of R as $S_R=\{a{\in}R{\mid}aRa=(0)\}$ and call it the source of semiprimeness of R. We first examine some basic properties of the subset $S_R$ in any ring R, and then define the notions such as R being a ${\mid}S_R{\mid}$-reduced ring, a ${\mid}S_R{\mid}$-domain and a ${\mid}S_R{\mid}$-division ring which are slight generalizations of their classical versions. Beside others, we for instance prove that a finite ${\mid}S_R{\mid}$-domain is necessarily unitary, and is in fact a ${\mid}S_R{\mid}$-division ring. However, we provide an example showing that a finite ${\mid}S_R{\mid}$-division ring does not need to be commutative. All possible values for characteristics of unitary ${\mid}S_R{\mid}$-reduced rings and ${\mid}S_R{\mid}$-domains are also determined.

Determination of Saturated and Unsaturated Fatty Acids Amount in Leukocyte Membranes from Subjects Fed with Solid and Fluid Oils

Erman, Fazilet,Aydin, Suleyman,Demir, Yasar,Akcay, Fatih,Bakan, Ebubekir Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.5

Modifications in dietary fatty acid intake might lead to a modification in membrane phospholipid fatty acid composition. The purpose of this study was to investigate relationship between different type of oil consumption and leukocyte membrane phospholipid composition. This study was carried out in subjects utilizing butter (n = 15), margarine (n = 15), fluid oil (n = 15) and mixed types of oils (n = 15) in total 60 subjects. Leukocytes were separated from total blood by dextran sedimentation method. Membrane lipids and proteins were isolated following the cell disruption. Fatty acids of membrane phospholipids were isolated by hydrolysation with phospholipase B under ultrasonic dismembranator. Free fatty acids were identified with gas chromatography at chloroform phase. The results obtained were compared with data obtained by chromatograms of the standards. Results more prominent values of arachidic, dihomo-$\gamma$-linolenic and palmitoleic acids were found in butter-or mixed oil-user groups; eicosadienoic, eicosamonoenoic, dihomo-$\gamma$-linolenic and behenic acids in fluid oil; heptanoic, valeric, eicosadienoic and linolenic acids in margarine groups. The fatty acid composition of mixed oil was similar to butter, while other two oils were so different. From this study, it was concluded that the type of oil consumption might have an influence on phospholipid components of plasma membranes.

A new approach to determine the moment-curvature relationship of circular reinforced concrete columns

Naci Caglar,Aydin Demir,Hakan Ozturk,Abdulhalim Akkaya 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.3

To be able to understand the behavior of reinforced concrete (RC) members, cross sectional behavior should be known well. Cross sectional behavior can be best evaluated by moment-curvature relationship. On a reinforced concrete cross section moment-curvature relationship can be best determined by both experimentally or numerically with some complicated iteration methods. Making these experiments or iterations manually is very difficult and not practical. The aim of this study is to research the efficiency of Neural Networks (NN) as a more secure and robust method to obtain the moment-curvature relationship of circular RC columns. It is demonstrated that the NN based model is highly successful to determine the moment-curvature relationship of circular reinforced concrete columns.

Determination of Saturated and Unsaturated Fatty Acids Amount in Leukocyte Membranes from Subjects Fed with Solid and Fluid Oils

( Fazilet Erman ),( Suleyman Aydin ),( Yasar Demir ),( Fatih Akcay ),( Ebubekir Bakan ) 생화학분자생물학회 2006 BMB Reports Vol.39 No.5

Predictive and Prognostic Significance of p27, Akt, PTEN and PI3K Expression in HER2-Positive Metastatic Breast Cancer

Okutur, Kerem,Bassulu, Nuray,Dalar, Levent,Aydin, Kubra,Bozkurt, Mustafa,Pilanci, Kezban Nur,Dogusoy, Gulen Bulbul,Tecimer, Coskun,Mandel, Nil Molinas,Demir, Gokhan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: The phosphatidylinositol 3'-kinase/Akt (PI3K/Akt) pathway is a key regulator for HER2-overexpressing breast cancer, but data about whether activation of PI3K/Akt is associated with poor prognosis and resistance to trastuzumab therapy is controversial. In this study we investigated predictive and prognostic significance of expression of p27, Akt, PTEN and PI3K, which are components of the PI3K/Akt signaling pathway, in HER2-positive metastatic breast cancer (MBC), retrospectively. Materials and Methods: Fifty-four HER2-positive MBC patients who had received first-line trastuzumab-based therapy were recruited for the study group. All of the patient's breast tissue samples were examined for p27 and Akt expression. In addition, twenty-five patients with sufficient amount of tumor tissue were also examined for PTEN and PI3K expression. p27, Akt, PTEN and PI3K were evaluated by immunohistochemistry and their relationship with patient demographic features, tumor characteristics, response to trastuzumab-based treatment and survival outcomes were analyzed. Results: p27, Akt, PTEN and PI3K were positive in 25.9%, 70.4%, 24% and 96% of the cases, respectively. Nomne were significantly associated with response to trastuzumab and time to progression (TTP). A trend toward statistical significance for longer overall survival (OS) was found for PTEN-positive patients (p=0.058); there was no significant relationship between the other immunohistochemical variables and OS. When we analyzed groups regarding co-expression, the PTEN-negative/Akt-negative group had a significantly lower objective response rate (ORR) (20% vs 80%, p=0.023) and the PTEN-negative/p27-negative and PTEN-negative/Akt-negative groups had significantly lower median OS compared to other patients (26.4 months vs 76.1 months, p=0.005 and 25.6 months vs 52.0 months, p=0.007, respectively). Conclusions: p27, Akt, PTEN and PI3K expression is not statistically significantly associated with ORR, TTP and OS, individually. However, the combined evaluation of p27, Akt and PTEN could be helpful to predict the response to trastuzumab-based therapy and prognosis in HER2-positive MBC.

Pleomorphic Carcinoma of the Lung with High Serum Betahuman Chorionic Gonadotropin Level and Gynecomastia

Kerem Okutur,Baris Hasbal,Kubra Aydin,Mustafa Bozkurt,Esat Namal,Buge Oz,Kamil Kaynak,Gokhan Demir 대한의학회 2010 Journal of Korean medical science Vol.25 No.12

Although gynecomastia is a well-defined paraneoplastic syndrome in patients with nonsmall cell lung cancer, the association with pleomorphic carcinoma has not been reported. A 50-yr-old man presented with bilateral gynecomastia and elevated serum beta-human chorionic gonadotropin (βhCG) level. Chest tomography showed a mass in the right middle lobe. Right middle lobectomy and mediastinal lymph node dissection were performed. βhCG levels decreased rapidly after surgery. Histological examination revealed pleomorphic carcinoma with positive immunostaining for βhCG. Serum βhCG levels began to increase gradually on postoperatively 4th month. Computed tomography detected recurrence and chemotherapy was started. After second cycle of chemotherapy, βhCG levels decreased dramatically again and tomography showed regression in mass. Patient died 6 months later due to brain metastasis. βhCG expression may be associated with aggressive clinical course and increased risk of recurrence, also βhCG levels may be used to evaluate therapy response in patients with pleomorphic carcinoma.

Lack of Variation in Inflammatory Hematological Parameters between Benign Nodular Goiter and Papillary Thyroid Cancer

Yaylaci, Selcuk,Tosun, Onder,Sahin, Orhan,Genc, Ahmet Bilal,Aydin, Ercan,Demiral, Gokhan,Karahalil, Fatma,Olt, Serdar,Ergenc, Hasan,Varim, Ceyhun Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: Inflammatory hematological parameters like the neutrophil/lymphocyte (N/L) ratio have been investigated in many cancer types and significant relationships found with prognosis, for example. The aim of this present study was to investigate the impact of hematological parameters notably on N/L ratio and mean platelet volume (MPV) in papillary thyroid cancer cases. Materials and Methods: A total of 79 patients who underwent a thyroidectomy operation in Findikli, Goiter Research and Treatment Center during 2011-2015 period were enrolled in the study, 41 with papillary thyroid cancer and 38 with benign goiter confirmed by pathological examination. We collected clinical and laboratory data for the patients from hospital records retrospectively. Blood samples taken at admission were assessed for parameters compared between the groups. Results: No significant differences between papillary thyroid cancer and benign goiter groups were apparent in terms of age, the N/L ratio, MPV, white blood cell count (WBC), red blood cell count (RBC), hemoglobin, hematocrit, platelet, neutrophil, lymphocyte, red blood cell distribution width (RDW) and platelet crit (PCT) levels (p>0.05). Only the level of platelet distribution width (PDW) significantly differed, being lower in the papillary cancer group (p<0.05). Conclusions: No significant relationship between papillary thyroid cancer and inflammatory hematological parameters including in particular the N/L ratio and MPV. The relevance of the PDW values remains unclear.