Development and Cyclic Behavior of U-Shaped Steel Dampers with Perforated and Nonparallel Arm Confi gurations

Kurtulus Atasever,Oguz C. Celik,Ercan Yuksel 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.5

Metallic dampers are sacrifi cial devices (fuses) that dissipate signifi cant energy during earthquakes while protecting other parts of structures from possible damage. In addition to numerous implementation opportunities of other base isolation systems, U-shaped dampers (UD) are one of the widely investigated and used devices in practice especially in Japan. The present study focuses on enhancing seismic performance of these types of dampers by changing their geometric properties. UDs with perforated (i.e. with holes) and/or nonparallel arms are developed for this purpose. For a better comparison, the criterion of equal material volume (or mass) has been utilized. Three dimensional fi nite element models of the new type of UDs are formed and investigated numerically under selected displacement histories. Based on the obtained hysteretic curves; dissipated energy intensities, eff ective stiff ness ratios, reaction forces, eff ective damping ratios are evaluated in this parametric study. It is found that both damper types have merits in use of seismic applications and that the selection of the damper confi guration is dependent on the design specifi c issues.

Evaluation of Quality of Life in Turkish Patients with Head and Neck Cancer

Akkas, Ebru Atasever,Yucel, Birsen,Kilickap, Saadettin,Altuntas, Emine Elif Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

Background: In this study, our aim was to investigate the effect of factors, such as radiotherapy, the dose of radiotherapy, the region of radiotherapy, the age of the patient, performance, co-morbidity, the stage of the disease and the therapy modalities on the quality of life of patients with head and neck cancer. Materials and Methods: Eighty-two patients who were treated by either chemoradiotherapy or radiotherapy, at the Cumhuriyet University Faculty of Medicine, Department of Radiation Oncology, between February 2007 and September 2010, for head and neck cancer were included. The quality of life European Organisation for Research and Treatment of Cancer, Questionnaire module to be used in Quality of Life assessments in Head and Neck Cancer (EORTC QLQ-H&N35) questionnaire was conducted in all patients before starting the radiotherapy, in the middle, at the end, at 1 month and at 6 months after the treatment. Results: According to the questionnaires at the end and at the $6^{th}$ month after the radiotherapy, it was found that the age of the patient, co-morbidity, ECOG performance state, localization, type of treatment, the stage of the disease, the dose and the region of radiotherapy affect some of the symptom scales for quality of life. Conclusions: Quality of life was affected negatively during and after the radiotherapy. However, in the $6^{th}$ month after the therapy, a significant improvement was observed in most symptoms.

Lack of Impact of Age on Acute Side Effects and Tolerance of Curative Radiation Therapy

Yucel, Birsen,Okur, Yillar,Akkas, Ebru Atasever,Eren, Mehmet Fuat Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Aim: The aim of this study was to determine the impact of age on the occurrence, severity, and timing of acute side effects related to radiotherapy. Materials and Methods: We analysed the data of 423 patients. Results: Of the patients, 295 (70%) were under the age of 65 (group 1) and 128 (30%) were over the age of 65 (group 2). The frequencies of radiotherapy-induced side effects were 89% in group 1 and 87% in group 2 (p=0.286). The mean times to occurrence were $2.5{\pm}0.1$ weeks in group 1 and $2.2{\pm}0.1$ weeks in group 2 (p=0.013). Treatment was ended in 2% of patients in group 1 and 6% of those in group 2 (p=0.062). Treatment interruption was identified in 18% of patients in group 1 and 23% in group 2 (p=0.142). Changes in performance status were greater in older patients (p=0.013). There were no significant differences according to the frequency or severity of side effects, except skin and genitourinary complications, between the groups. Conclusions: Early normal tissue reactions were not higher in older versus younger patients, though there was a tendency towards an earlier appearance.

Oral Glutamine Supplementation Reduces Radiotherapy-induced Esophagitis in Lung Cancer Patients

Gul, Kanyilmaz,Muge, Akmansu,Taner, Atasever,Sehri, Elbag Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.1

Background: The purpose of this study was to assess the the efficacy of oral glutamine (GLN) in prevention of acute radiation-induced esophagitis in patients with lung cancer and determine the predictive role of clinical and dosimetric parameters. Materials and Methods: Thirty-two patients diagnosed with lung cancer were studied prospectively. Sixteen patients (50%) received prophylactic powdered GLN orally in doses of 10g/8h. Patients were treated 2 Gy per fraction daily, 5 days a week. We evaluated the grading of esophagitis daily at the end of each fraction of each treatment day until a cumulative dose of 50 Gy was reached. The primary end point was radiation-induced esophagitis. Results: All patients tolerated GLN well. Toxicity grade, weight loss, serum cytokine levels and esophageal transit times exhibited statistically significant improvement in the GLN receiving group. GLN suppressed the inflammation related to the disease and treatment and reduced toxicity with statistical significance. Conclusions: This study suggests a benefical role of oral GLN use in prevention and/or delay of radiation-induced esophagitis, in terms of esophageal transit time and serum immunological parameters, as well as weight loss.

Recently Emerging Signaling Landscape of Ataxia-Telangiectasia Mutated (ATM) Kinase

Farooqi, Ammad Ahmad,Attar, Rukset,Arslan, Belkis Atasever,Romero, Mirna Azalea,ul Haq, Muhammad Fahim,Qadir, Muhammad Imran Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Research over the years has progressively and sequentially provided near complete resolution of regulators of the DNA repair pathways which are so important for cancer prevention. Ataxia-telangiectasia mutated kinase (ATM), a high-molecular-weight PI3K-family kinase has emerged as a master regulator of DNA damage signaling and extensive cross-talk between ATM and downstream proteins forms an interlaced signaling network. There is rapidly growing scientific evidence emphasizing newly emerging paradigms in ATM biology. In this review, we provide latest information regarding how oxidative stress induced activation of ATM can be utilized as a therapeutic target in different cancer cell lines and in xenografted mice. Moreover, crosstalk between autophagy and ATM is also discussed with focus on how autophagy inhibition induces apoptosis in cancer cells.

Whole Brain Radiotherapy Combined with Stereotactic Radiosurgery versus Stereotactic Radiosurgery Alone for Brain Metastases

Adas, Yasemin Guzle,Yazici, Omer,Kekilli, Esra,Akkas, Ebru Atasever,Karakaya, Ebru,Ucer, Ali Riza,Ertas, Gulcin,Calikoglu, Tamer,Elgin, Yesim,Inan, Gonca Altinisik,Kocer, Ali Mert,Guney, Yildiz Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: The aim of this study was to evaluate the effect of whole brain radiotherapy (WBRT) combined with streotactic radiosurgery versus stereotactic radiosurgery (SRS) alone for patients with brain metastases. Materials and Methods: This was a retrospective study that evaluated the results of 46 patients treated for brain metastases at Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Radiation Oncology Department, between January 2012 and January 2015. Twenty-four patients were treated with WBRT+SRS while 22 patients were treated with only SRS. Results: Time to local recurrence was 9.7 months in the WBRT+SRS arm and 8.3 months in SRS arm, the difference not being statistically significant (p=0.7). Local recurrence rate was higher in the SRS alone arm but again without significance (p=0,06). Conclusions: In selected patient group with limited number (one to four) of brain metastases SRS alone can be considered as a treatment option and WBRT may be omitted in the initial treatment.