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Keywords: aging, sensory performance, motor performance, cognitive performance, multisensory integration
Published in DiRROS: 22.01.2024; Views: 316; Downloads: 124
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Abstract: Within previous investigation alkali activation of waste casting cores at room temperature did not give promising results, i.e. when the precursor was gently ground and sieved below 600 %m the alkali activated material fell apart at demolding, and when the precursor was ground below 90 %m, the alkali activated material did not solidify in more than 2 years. , Therefore different drying/curing methods were applied to enhance the reaction. Waste casting cores were prepared in two granulations (sieved below 600 %m and below 90 %m), activated with Na -water glass and 10 M NaOH, cured at different temperatures (70 °C and room temperature), and subsequently cured/dried at three different conditions: room temperature, 110 °C, and irradiated with microwaves. The highest compressive strength, 25 MPa, was gained with subsequent curing/drying at 110 °C. The lowest density, 0.5 kg/l, with compressive strength above 3 MPa, was achieved with subsequent curing/drying with microwaves .
Keywords: waste casting cores, alkali activation, curing, drying, microwaves, mechanical strength
Published in DiRROS: 22.01.2024; Views: 312; Downloads: 175
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Abstract: Background. Position sensitive silicon microstrip detectors are used as sensors for X rays in a digital imaging system. Silicon detectors were used inan edgeon geometry, yielding high X ray detection efficiency. Material and methods. A small detector system was assembled and tested. Images of a standard, 5 cm thick phantom were made and evaluated. It is demonstrated, thatthe use of silicon detectors in mammography could significantly contributeto a reduction of dose. All images were made with skin entrance doses lower than 1 mGy. Results and conclusion. Microcalcifications with a diameter of 350microm could still be detected with skin entrance doses of about 0.25 mGy. It was demonstrated that a 5 Ip/mm pattern can be detected. Image processing should further improve the image quality.
Published in DiRROS: 22.01.2024; Views: 347; Downloads: 70
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Abstract: Background. The aim of this work was to study the configuration of the microtubules in the cytochalasin B treated V-79 cells in connection to the cell shape and to see whether there are any similarities to the phenomena taking place in phospholipid vesicles. Subjects and methods. An experiment wasperformed where cytochalasin B was added to the V-79 cells (lung fibroblasts of Chinese hamster). Results. The cell shape changed from an elongated one into the shape with a profile resembling the Greek letter phi. The microtubules were found to be organized into a rod within the symmetry axis of the cell. Conclusion. As similar shapes were previously observed also in the phospholipid vesicles with entrapped microtubule rods, our results support the hypothesis that similar physical mechanisms may pertain in simple systems as well as in living cells.
Published in DiRROS: 22.01.2024; Views: 304; Downloads: 53
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Abstract: Background. The aim of the study was the evaluation of clinical utility and comparison of 111 In-DTPA- octreotide receptor scintigraphy (SRS) with conventional imaging modalities (CIM) in the detection of carcinoid tumor. Patients and methods. Fourteen patients with pathohistologically proven diagnosis of carcinoid tumor and one patient with clinical suspicion of carcinoid tumor were investigated by SRS. SRS was performed for localization of primary tumor, recurrence or estimation of spread of the disease after CIM had been completed. Whole body scans and single photon emission computed tomography (SPECT) were acquired 6 and 24 h after the application of radiopharmaceutical. The intensity of nonspecific radiopharmaceutical uptake in the bowel was assessed semiquantitatively by a score using whole body scans. Results. The evaluation was done for patients and for tumor sites. The sensitivity, specificity, and positive and negative predictive values for patient evaluation were 89 %,100 %,100 % and 80 %, respectively for both CIM and SRS, whereas for tumor sites, these parameters were 69 % 100 %,100 % and 82 % for CIM, and 88%,100%,100% and 92 % for SRS. Intensity score of nonspecific 111In-octreotide bowel accumulation was 0.92 and 2.01 for 6 and 24h scans respectively (p < 0.01). Conclusion. 111In-octreotide scintigraphy should be included in the diagnostic algorithm for the patients with clinical suspicion of carcinoid and for the assessment of patients with proven carcinoid tumor.
Published in DiRROS: 22.01.2024; Views: 234; Downloads: 45
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