China
Africa
Explore chapters and articles related to this topic
Scintillation Detectors
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Scintillation as a dedicated detection method played a central role both for Wilhelm Röntgen using scintillation screens of barium platinocyanide in the discovery of X-rays and for Ernest Rutherford in his formulation of a new atom model. Rutherford’s data were largely based on observations made by Hans Geiger and Ernest Marsdon who, with great patience, observed the faint scintillations from a zinc sulphide screen bombarded by alpha particles deflected in a gold foil. At the time no technique was available to amplify the weak light flashes, so the human eye and a completely dark room were the prerequisites for these human scintillation counters. As Birks [2] states in his introduction chapter to The Theory and Practice of Scintillation Counting – these were truly men of vision.
Principles of Radiation Detection and Image Formation
Published in Ken Holmes, Marcus Elkington, Phil Harris, Clark's Essential Physics in Imaging for Radiographers, 2021
Scintillation crystals/photocathode multipliers have a role as scintillation counters within nuclear medicine and the gamma camera is an extensively modified scintillation counter (Figure 6.5). They were also used as an early type of detector primarily with first and second generation CT scanners.
Instrumentation for Detection of Radioactivity
Published in Graham Lappin, Simon Temple, Radiotracers in Drug Development, 2006
Scintillation counters measure the photons produced by the scintillator. These photons are produced in proportion to the intensity of the energy of the isotope being analyzed. The intensity and number of photons are registered by photomultipliers (Section 6.3). The signal from the photomultiplier ultimately ends up as a data readout. Between the photomultiplier and the readout are the electronics and it is here where there has been concentrated effort to reduce the signals from background noise. Without doubt, the use of coincidence counting (Section 6.3) contributed substantially to the reduction of background, and this was followed by improvements in photomulti-plier tube design and low-activity lead shielding, often combined with other metals.
Exploration of novel heterofused 1,2,4-triazine derivative in colorectal cancer
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Justyna Magdalena Hermanowicz, Anna Szymanowska, Beata Sieklucka, Robert Czarnomysy, Krystyna Pawlak, Anna Bielawska, Krzysztof Bielawski, Joanna Kalafut, Alicja Przybyszewska, Arkadiusz Surazynski, Adolfo Rivero-Muller, Mariusz Mojzych, Dariusz Pawlak
DLD-1 and HT-29 cells were cultured in six-well plates and treated with various concentrations (1 µM, 3 µM, and 10 µM) of the tested compound and reference drugs, RSC and 5-FU, for 24 h. Following the incubation, the cells were treated with 0.5 µCi of radioactive [3H]thymidine (specific activity 6.7 Ci/mmol) for 4 h in optimal growth condition. Afterward, the medium was removed and cells were washed two times with 1 mL of 0.05 M Tris–HCl buffer containing 0.11 M NaCl. In the next step, the cells were washed twice with 1 mL of 5% TCA acid and then dissolved in 1 mL of 0.1 M NaOH containing 1% SDS. Following 5 min of incubation, the obtained cell lysates were transferred to scintillation vials previously filled with 2 mL scintillation fluid. The radioactivity was quantified on Scintillation Counter (Packard Tri-Carb Liquid Scintillation Counter 1900 TR, Perkin Elmer, Inc., Waltham, MA). [3H]thymidine uptake was expressed as dpm/well. The intensity of DNA biosynthesis in the control was taken as 100%. The values from the samples were obtained from three independent experiments done in duplicate (N = 6) and presented as a percentage of the control cells.
99mTc-labelled and pH-awakened microbeads entrapping surface-modified lipid nanoparticles for the augmented effect of oxaliplatin in the therapy of colorectal cancer
Published in Journal of Microencapsulation, 2020
Kuldeep Rajpoot, Sunil K. Jain
The organ distribution study was carried out using Balb/c mice for each labelled formulation per time point. Five groups of mice (for five different time point i.e. 6, 8, 12, 24, and 48 h) were selected for organ distribution study. Each group was consisted of three mice (n = 3) for each formulation i.e. (99mTc-EuB-FA-SLN-OP and 99mTc-EuB-SLN-OP). The radiolabeled MBs (0.1 mCi) such as 99mTc-EuB-SLN-OP and 99mTc-EuB-FA-SLN-OP containing OP (3.75 mg/kg) was administered orally using a syringe. The animals were positioned in a slanted posture at the time of dosing. The animals were mercy killed at specific time intervals and a definite volume of blood was taken out through the retro-orbital vein. At the same time, various organs were removed and weighed. Finally, the blood sample and organs were subjected to radioactivity counts under the shielded gamma scintillation counter. The distribution of the radiopharmaceutical in organs was determined as a fraction of the dose per gram of organ/tissue.
Enhancement in brain uptake of vitamin D3 nanoemulsion for treatment of cerebral ischemia: formulation, gamma scintigraphy and efficacy study in transient middle cerebral artery occlusion rat models
Published in Journal of Microencapsulation, 2020
Mukesh Kumar, Dhruv Kumar Nishad, Anoop Kumar, Aseem Bhatnagar, Ritu Karwasra, Kushagra Khanna, Keerthana S, Deeksha Sharma, Kamal Dua, Vijaybabu Mudaliyar, Nitin Sharma
Biodistribution study of 99mTc-vitamin D3-nanoemulsion and 99mTc-vitamin D3 oil solution was performed using a radiometry method with little modifications (Md et al. 2013). The animals of each group were sacrificed at different time intervals (1, 2, 4, and 24 h), the abdominal cavity was exposed by 3 cm ventral midline incision and different organs (brain, liver, kidney, spleen, and heart) were collected. Organs were washed twice using saline and weight was recorded. Radioactivity quantification in every organ was done using a well-type gamma scintillation counter (Capintec, New Jersey, USA). The following equation was used to measure the uptake of 99mTc labelled vitamin D3 in each organ.