A study about determination of preliminary design & minimum reinforcement ratios

Varol KOC,Yusuf EMİROGLU 사단법인 한국계산역학회 2016 Computers and Concrete, An International Journal Vol.17 No.5

In the standards, minimum reinforcement ratios are presented as the least reinforcement ratios that bearing elements should have in a way to include all systems and in general. However, naturally these general minimum ratios might be presented as being lower than the normally required reinforcement ratios by criteria such as system size, bearing system arrangement, section situation and distributions of the elements and earthquake effect. In this case, minimum reinforcement ratios may remain as meaningless restrictions. Then grouping the criterion that might affect reinforcement ratios according to certain parameters and creating minimum reinforcement ratios regarding preliminary design will provide ease and safety during the project designing. Moreover, it will enable fast and simple examinations in the beginning of project control and evaluation process. By means of the data which could be defined as “preliminary design & minimum reinforcement ratios”, a more realistic and safe restriction compared to general minimum reinforcement ratios could be presented. As a result of numerous comprehensive studies, reinforcement ratios to include all certain systems might be obtained. Today, thanks to the development level of finite elements programs which can make reinforced concrete modelling, with the studies that are impossible to carry out beforehand, this deficiency in the minimum reinforcement ratios in the standarts may at least be partially made up with the advisory regulation of preliminary design & minimum reinforcement ratios. As the structure of the system to be examined and the diversity of the parameters range from the specific to the general, preliminary design & minimum reinforcement ratios will approximate to general minimum reinforcement ratios in real terms. By focusing on a more specific system structure and diversity of the parameters, preliminary design and even design reinforcement ratios will be approximated. In this preliminary study, a route between these two extremes was attempted to be followed. Today, it is possible to determine suggested practical ratios for project designs through carrying out numerous studies.

Anticancer Therapy for Breast Cancer Patients with Skin Metastases Refractory to Conventional Treatments

Varol, Umut,Yildiz, Ibrahim,Alacacioglu, Ahmet,Uslu, Ruchan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Skin metastases of breast cancer are usually late events in the course of tumor progression and signify a poor prognosis. They may remain as a therapeutic challenge especially after failure of standard treatments. Topical interventions, together with or without radiotherapy, may only palliate the symptoms temporarily. However, there may be alternative treatment modalities for unresectable breast cancer skin metastases resistant to chemotherapy and radiotherapy. There are various genetic alterations in tumors and therapeutic potential of expression patterns for factors like epidermal growth factor receptor may have important clinical implications in case of disease refractory to the conventional treatments. Here, we clarified the therapeutic options and genetic alterations in skin metastatic breast cancer patients refractory to standard chemotherapeutics.

First-Line Mono-Chemotherapy in Frail Elderly Patients with Metastatic Colorectal Cancer

Varol, Umut,Dirican, Ahmet,Yildiz, Ibrahim,Oktay, Esin,Degirmenci, Mustafa,Alacacioglu, Ahmet,Barutca, Sabri,Karabulut, Bulent,Uslu, Ruchan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

Background: Unlike for fit elderly metastatic colorectal cancer (mCRC) patients, general approaches to initial treatment for the frail older mCRC patients are not clear. Our aim was to evaluate the efficiency and safety of first-line single-agent treatment in one such group. Materials and Methods: We retrospectively evaluated mCRC patients aged 70 or older with an Eastern Cooperative Oncology Group performance score of 2. They had no prior treatment and underwent first-line single-agent capecitabine or other monotherapies until disease progression or unacceptable toxicity. Results: Thirty-six patients were included. Most (n:28, 77.8%) were treated with capecitabine. One patient achieved a complete response and 5 patients had a partial response for an overall response rate of 16.6%. Twelve patients (33.3%) remained stable. Median progression free survival was 5 months (confidence interval (CI), %; 3.59-6.40) and median overall survival was 10 months (95 CI%; 8.1-11.8). Grade 3-4 toxicity was found in 6 patients (16.6%). Febrile neutropenia was not observed and there were no toxicity-associated deaths. Conclusions: Capecitabine is a safe chemotherapeutic agent with moderate activity for first-line treatment of older metastatic colorectal cancer patients with limited performance status.

Transcriptomic analysis of the heat stress response for a commercial baker’s yeast Saccharomyces cerevisiae

Duygu Varol,Vilda Purutçuoğlu,Remziye Yılmaz 한국유전학회 2018 Genes & Genomics Vol.40 No.2

The aim of this study is to explore the effects of heat stresses on global gene expression profiles and to identify the candidate genes for the heat stress response in commercial baker’s yeast (Saccharomyces cerevisiae) by using microarray technology and comparative statistical data analyses. The data from all hybridizations and array normalization were analyzed using the GeneSpringGX 12.1 (Agilent) and the R 2.15.2 program language. In the analysis, all required statistical methods were performed comparatively. For the normalization step, among alternatives, the RMA (Robust Microarray Analysis) results were used. To determine differentially expressed genes under heat stress treatments, the fold-change and the hypothesis testing approaches were executed under various cut-off values via different multiple testing procedures then the up/down regulated probes were functionally categorized via the PAMSAM clustering. The results of the analysis concluded that the transcriptome changes under the heat shock. Moreover, the temperature-shift stress treatments show that the number of differentially up-regulated genes among the heat shock proteins and transcription factors changed significantly. Finally, the change in temperature is one of the important environmental conditions affecting propagation and industrial application of baker’s yeast. This study statistically analyzes this affect via one-channel microarray data.

Microstructure, Electrical Conductivity and Hardness of Multilayer Graphene/ Copper Nanocomposites Synthesized by Flake Powder Metallurgy

T. Varol,A. Canakci 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.4

In this study, the influence of multilayer graphene content on the green and sintered properties of the multilayer graphene/Copper nanocomposites was investigated. Flake powder metallurgy, as a new production method, was employed to prepare the multilayer graphene reinforced copper matrix nanocomposites. Results showed that the increase in agglomeration content inhibited particle-particle contact during the sintering process and therefore sintered density decreased with increasing the multilayer graphene content. The green density of 8.46 g/cm3 was found for the monolithic Cu sample, which was 16.4% higher than that of the 5 wt% MLG/ Copper nanocomposites. The high conductivity value (78.5 IACs) was obtained with 0.5 wt% the multilayer graphene reinforced nanocomposites. The electrical conductivity of sintered 5 wt% the multilayer graphene/Copper nanocomposites was 61.48 IACs. When the amount of the multilayer graphene particles as higher than 3 wt%, the decreasing rate in hardness significantly increased. The decreasing rate in the hardness of the multilayer graphene/Copper nanocomposites can be attributed to decrease in density and the non-homogeneous distribution of multilayer graphene particulates in Cu matrix.

Effect of Weight Percentage and Particle Size of B4C Reinforcement on Physical and Mechanical Properties of Powder Metallurgy Al2024-B4C Composites

T. Varol,A. Canakci 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.6

In this study, Al2024-B4C composites containing 0, 5, 10 and 20 wt% of B4C particles with two different particle sizes (d50=49 μm and d50=5 μm) as reinforcement material were produced by a mechanical alloying method. Two new particle distribution models based on the size of reinforcement materials was developed. The microstructure of the Al2024-B4C composites was investigated using a scanning electron microscope. The effects of reinforcement particle size and weight percentage (wt%) on the physical and mechanical properties of the Al2024-B4C composites were determined by measuring the density, hardness and tensile strength values. The results showed that more homogenous dispersion of B4C powders was obtained in the Al2024 matrix using the mechanical alloying technique according to the conventional powder metallurgy method. Measurement of the density and hardness properties of the composites showed that density values decreased and hardness values increased with an increase in the weight fraction of reinforcement. Moreover, it was found that the effect of reinforcement size and reinforcement content (wt%) on the homogeneous distribution of B4C particles is as important as the effect of milling time.

Aortic Stiffness in Patients with Deep and Lobar Intracerebral Hemorrhage: Role of Antihypertensive Drugs and Statins

Ercan Varol,Mehmet Ozaydin 대한뇌졸중학회 2015 Journal of stroke Vol.17 No.1

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Rare Cause of Hematochezia in Children: Solitary Rectal Ulcer, Single Center Experience

Fatma İlknur Varol,Şükrü Güngör,Mukadder Ayşe Selimoğlu,Emine Şamdancı 대한소화기학회 2024 대한소화기학회지 Vol.83 No.1

Background/Aims: Solitary rectal ulcer syndrome (SRUS) can be overlooked, diagnosed late, or misdiagnosed, particularly in childhood. This study reviewed the 13-year experience of the authors’ institution to increase clinicians' awareness of SRUS in the presence of symptoms. This paper reports the endoscopic and histopathological findings in children presenting with hematochezia. Methods: The clinical and laboratory findings of 22 patients diagnosed with biopsy-proven SRUS in the authors’ clinic between 2007 and 2020 were evaluated retrospectively. Results: The mean age at diagnosis was 12.5±2.6 years, and 59.1% of the patients were male. The median time of diagnosis was 24 months. A single ulcer lesion was found by colonoscopy in 18 patients (81.8%), two ulcers in two patients (9%), and more than two ulcers in two patients (9%). The pathology reports of all biopsies taken from the lesions were consistent with a solitary rectal ulcer. In the first stage, the treatment was started with toilet training, a high-fiber diet, and laxatives. In 11 patients (50%) who did not respond to the initial treatment, a 5-ASA enema was added. A glucocorticoid enema was added to treatment in five patients (22%) whose complaints did not regress despite this treatment. Clinical remission was achieved in five of the patients (18.1%). The time to diagnosis was significantly shorter in those in remission than those not in remission (p=0.04). Conclusions: This study is the first large series on Turkish children. An increased awareness of SRUS in children will increase the rate of early diagnosis and treatment, allowing remission in more patients.

Treatment of Metastatic Colorectal Cancer With or Without Bevacizumab: Can the Neutrophil/Lymphocyte Ratio Predict the Efficiency of Bevacizumab?

Dirican, Ahmet,Varol, Umut,Kucukzeybek, Yuksel,Alacacioglu, Ahmet,Erten, Cigdem,Somali, Isil,Can, Alper,Demir, Lutfiye,Bayoglu, Ibrahim Vedat,Akyol, Murat,Yildiz, Yasar,Koyuncu, Betul,Coban, Eyup,Tarh Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: The purpose of this study was to analyze the predictive value of neutrophil/lymphocyte ratio (NLR) to better clarify which patient groups will benefit the most from particular treatments like bevacizumab. Materials and Methods: A total of 245 treatment-naive metastatic colorectal cancern (mCRC) patients were retrospectively enrolled and divided into 2 groups: 145 group A patients were treated with chemotherapy in combination with bevacizumab, and 100 group B patients were treated as above without bevacizumab. Results: Group A patients had better median overall survival (OS) and progression-free survival (PFS) (24.0 and 9.0 months) than group B patients (20 and 6.0 months) (p=0.033; p=0.015). In patients with low NLR, OS and PFS were significantly longer in group A patients (27 vs 18 months, p=0.001; 11 vs 7 months, p=0.017). Conclusions: We conclude that NLR, a basal cancer related inflammation marker, is associated with the resistance to bevacizumab-based treatments in mCRC patients.

Investigations on the effects of mouthrinses on the colour stability and surface roughness of different dental bioceramics

Soygun, Koray,Varol, Osman,Ozer, Ali,Bolayir, Giray The Korean Academy of Prosthodonitics 2017 The Journal of Advanced Prosthodontics Vol.9 No.3

PURPOSE. In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS. One hundred and twenty ceramic samples, with dimensions of $2{\times}12{\times}14mm$, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS. There was a positive correlation between the ${\Delta}E$ and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ${\Delta}E$ and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.