2,244 research outputs found
Development of a hybrid magnetic resonance/computed tomography-compatible phantom for magnetic resonance guided radiotherapy
The purpose of the present study was to develop a hybrid magnetic resonance/computed tomography (MR/CT)-compatible phantom and tissue-equivalent materials for each MR and CT image. Therefore, the essential requirements necessary for the development of a hybrid MR/CT-compatible phantom were determined and the development process is described. A total of 12 different tissue-equivalent materials for each MR and CT image were developed from chemical components. The uniformity of each sample was calculated. The developed phantom was designed to use 14 plugs that contained various tissue-equivalent materials. Measurement using the developed phantom was performed using a 3.0-T scanner with 32 channels and a Somatom Sensation 64. The maximum percentage difference of the signal intensity (SI) value on MR images after adding K2CO3 was 3.31%. Additionally, the uniformity of each tissue was evaluated by calculating the percent image uniformity (%PIU) of the MR image, which was 82.18 ±1.87% with 83% acceptance, and the average circular-shaped regions of interest (ROIs) on CT images for all samples were within ±5 Hounsfield units (HU). Also, dosimetric evaluation was performed. The percentage differences of each tissue-equivalent sample for average dose ranged from -0.76 to 0.21%. A hybrid MR/CT-compatible phantom for MR and CT was investigated as the first trial in this field of radiation oncology and medical physics
In vitro selection of salt-tolerant Ailanthus altissimaSwingle
Salt-tolerant cell lines of Ailanthus altissima were selected from callus derived protoplasts. Murashige–Skoog (MS) liquid medium incorporated with various concentrations of NaCl was employed to enrich salt-tolerant A. altissima cell lines. Salt-resistant A. altissima cells were transferred on MS solid medium supplemented with 2.5 μM 2,4-dichlorophenoxy acetic acid (2,4-D), 0.5 μM benzyl adenine (BA) and various NaCl concentrations. The callus was cultured on MS medium containing NaCl for 5 months, to determine the survival rate as an index of salt tolerance. The measurement of growth parameters for salt-tolerant cells showed that the selected plant cell lines grew better than the unselected ones at all levels of NaCl tested. The salt-tolerant callus accumulated proline in correlation to the concentration of salts. Media supplemented with BA induced shoot differentiation of salt-resistant A. altissima cells
Selection of high berberine yielding phellodendron insulare nak. lines and the antimicrobial activity of their extracts
High berberine yielding Phellodendron insulare Nak. lines were selected by aggregate cloning method and the antimicrobial activity of their extracts was assessed. The berberine producing cork tree lines were selected by adopting a colorimetric method. In all 300 high berberine producing lines were selected with a colorimetric reagent containing 5M HCl and H2O2 and established from dissociated cell aggregates. The crude extracts from these lines showed antibacterial activities against tested Escherichia coli, Staphylococcus aureus, Salmonella typhimulium, and Listeria monocytogenes. The cork tree extracts were found to be inhibitory to these test organisms. Further the antimicrobial activity of plant extracts was on par with the berberine isolated from the extracts from native cork trees. These results have potential for developing alternative plant products as antimicrobial substances for application in agriculture and food industry
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