64 research outputs found

    Large Dimension and Low-Cost Fe-SMA Rods

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    The effects on sample size on abnormal grain growth in inexpensive FeMnAlNi shape memory alloy (SMAs) wires and rod were investigated. It was shown that repeated heat treatments between single phase (bcc) and two phase (bcc + fcc) region resulted in abnormal grains with bamboo structure both in small sized wires and large diameter rods. Microstructural features were investigated using electron backscatter diffraction (EBSD) and it was found that 0.5 mm wires possess strong [011] texture whereas, large diameter rods have random texture after grain growth heat treatments

    Integrated Health Monitoring of Transportation Structures with Magnetic Fe-SMA Wires

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    In this work, the magnetization response of FeMnAlNi superelastic shape memory alloys (SMAs) is investigated under stress. Wires with a diameter of 0.5 mm were subjected to repeated abnormal grain growth heat treatments in order to obtain bamboo structured oligocrystalline grains that are necessary for superelasticity. Solution heat treated wires were aged at 200ºC for 3 h to strengthen the austenite matrix. Tensile cyclic tests were performed at room temperature until failure, while the magnetization response of the wires was monitored using a hall sensor during loading and unloading in each cycle. It is observed that after each cycle, overall magnetization of the alloy decreases once the irrecoverable strain is introduced after large deformations and magnetization of the sample is inversely correlated with the irrecoverable strain. The findings of this work show that the magnetic shift in Fe-SMAs under deformation can be used a health monitoring tool in next generation structures to detect large deformations and cracks

    Upper Extremity Work-related Musculoskeletal Disorders among Computer Users and Effectiveness of Ergonomic Interventions

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    During the last two decades, computer use in the workplace has increased dramatically. Along with the increase in the productivity, the presence of computer in the workplace leads to changes in the workplace organizations and to emergence of new risk factors, thus causing many health problems such as upper extremity work-related musculoskeletal disorders (UE-WMSD) among computer users. The prevention of UE-WMSD, which frequency increases continuously, is possible with applying proper body mechanics and providing an ergonomic workplace. An approach that encloses the employer's support and the active employee participation will increase the success of these programs

    Large Dimension and Low-Cost Fe-SMA Rods

    No full text
    The effects on sample size on abnormal grain growth in inexpensive FeMnAlNi shape memory alloy (SMAs) wires and rod were investigated. It was shown that repeated heat treatments between single phase (bcc) and two phase (bcc + fcc) region resulted in abnormal grains with bamboo structure both in small sized wires and large diameter rods. Microstructural features were investigated using electron backscatter diffraction (EBSD) and it was found that 0.5 mm wires possess strong [011] texture whereas, large diameter rods have random texture after grain growth heat treatments

    Molecular and functional analysis of a novel recombinant clone of rat (Rattus norvegicus) CD40 ligand (CD40L) gene

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    Esendagli, Gunes/0000-0003-4865-2377;WOS: 000262088100011PubMed: 17922253Genetic material obtained from various individuals may contain certain polymorphisms which may conflict with the predetermined DNA sequence and consequently, may modulate the function of gene products. In this study, coding sequence of rat CD40 ligand (CD40L, CD154) was obtained from activated splenocytes, amplified, and cloned into a eukaryotic expression vector by using directional cloning method. Sequence of the recombinant rat CD40L DNA, pCD40L-IRES2-EGFP (pCD40L), was compared with the previously reported rat CD40L cDNA sequences and a 99% identity was found. Differing nucleotides were on the positions; 122-T/C, 341-G/A, 476G/A, 762-T/A. Further alignment analysis showed that pCD40L was collectively carrying the nucleotides each previously reported by different groups. The sequence was submitted to NCBI GenBank and nucleotide database accession number EF066490 was obtained. Following transfection of the construct into NIH/3T3 cell line, novel CD40L clone was functionally expressed de novo, increasing the expression of CD80 and CD86 costimulatory molecules and augmenting the proliferation rate of effector splenocytes in immune reactions ex vivo. Based on these data, here we report a novel recombinant clone of the rat CD40L gene which may represent a potential polymorphic variant.Eczacibasi Scientific Research and Award Fund; Hacettepe UniversityHacettepe University [05DO3104001]This study was supported by Eczacibasi Scientific Research and Award Fund, and Hacettepe University Scientific Research Unit (project no. 05DO3104001)

    Adhesion of beta1 integrin to fibronectin regulates CAM-DR phenotype via p21(WAF1/cip1) in HL60 acute myeloid leukemia (AML) cells

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    Esendagli, Gunes/0000-0003-4865-2377;WOS: 000254702300001Aims: Drug resistance is a major obstacle for a successful cancer therapy. Cell adhesion mediated drug resistance (CAM-DR) is a novel type of drug resistance and generated via interaction of cancer cells with the microenvironment. In this study, CAM-DR phenotype was analyzed in HL60 acute myeloid leukemia (AML) cells. Materials and Methods: Fibronectin (FN) adherence of HL60 cells was tested by a colorimetric adhesion assay. Flow cytometry analyses were performed to evaluate doxorubicin-incluced apoptosis and to determine cell cycle status. Proliferation rate was evaluated by [H-3]-thymidine incorporation assay. Western blot and RTPCR were used for analysis of the factors involved in cell cycle control. Results: Binding of HL60 to FN via alpha 4 beta 1 and alpha 5 beta 1 integrins exerted a CAM-DR phenotype, which shows resistance to apoptosis triggered by doxorubicin. FN-adherent HL60 cells accumulated in the G(0)/G(1) phase of cell cycle and stopped proliferation. However, after detachment from FN, cells entered S phase, proliferated, and became sensitive to apoptosis. The analysis of the factors involved in the G(0)/G(1) cell cycle checkpoint showed that CAM-DR phenotype might be regulated mainly by p21(waf/cip). Conclusions: Here we showed that CAM-DR may also represent a reversible drug resistance mechanism that decreases apoptosis and causes growth arrest in AML blasts

    Importance of the heart borders as a fluoroscopic clue for cardiac tamponade

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    Every catheter laboratory is equipped with an X-ray system designed to provide fluoroscopic imaging of the heart. Although cardiac catheters are well visualized in all X-ray imaging, the soft tissue of myocardium is not. Therefore the imaging of the cardiac chambers is indirect through relation to the cardiac silhouette. However, fluoroscopy can be used to detect complications from the invasive procedures in the cardiac catheterization laboratory, such as cardiac tamponade where the excursion of the cardiac silhouette decreases, and visceral and parietal pericardium are seen separated by the blood of accumulation in the pericardial cavity. Even if a transthoracic or intracardiac echocardiography guidance is immediately available, early fluoroscopic detection of tamponade should be remembered during the invasive procedures in the cardiac catheterization laboratory

    Palliative treatment of coronary “atherosclerotic cancer” by drug-eluting or bare-metal stents: From oculo-stenotic reflex period to age of precision medicine

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    Medications and treatments are said to have a palliative effect if they relieve symptoms without having a curative effect on the underlying disease such as atherosclerosis or cancer. Some authors speculated that atherosclerotic coronary artery disease (CAD) could be considered a “cancer of the coronary arterial wall”. Although the percutaneous coronary intervention (PCI) has proven to be effective in decreasing mortality rates among patients with acute coronary syndromes, the previous meta-analyses of PCI versus optimal medical therapy for stable CAD have not been able to demonstrate a reduction in major adverse cardiac outcomes. However, few cardiologists discussed the evidence-based benefits of angiogram and PCI for stable CAD, and some implicitly or explicitly overstated the benefits. Recently, the precision medicine is defined as an evidence-based approach that uses innovative tools and biological and data science to customize disease prevention, detection, and treatment, and improve the effectiveness and quality of patient care. Providing patients with accurate and complete information appears to be an effective way to combat the reliance on the oculostenotic reflex. The foundation of precision medicine is the ability to tailor therapy based upon the expected risks and benefits of treatment for each individual patient. As said by Doctor William Osler, “The good physician treats the disease; the great physician treats the patient who has the disease.
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