Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SCINTILLATION COUNTER”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 847 records · Page 47Linked to original sources
PubMed1978

Total and local X-radiation effects on 18F uptake of bones.

Flourine uptake in rat bones under local and total-body X-irradiation was studied. Data were obtained by measurements with a scintillation crystal counter and in the case of limbs by means of macro and microautoradiographies. The autoradiographic studies showed a higher concentration of the isotope in the metaphyseal area of the endochondral plate. Irradiation produced a depression of 18F uptake in both cases. An alteration in the mineralization mechanism due to irradiation is presumed.

Animals↗
PubMed1981

Time dependence of iprofenin-labeling with technetium Tc 99m.

The incubation time required to attain 90% labeling efficiency (90% radiochemical purity) for technetium Tc 99m labeling of iprofenin (PIPIDA, Diagnostic Isotopes, Inc.), was investigated. Thirty iprofenin vials were prepared according to the manufacturer's instructions. Aliquots were withdrawn from 12 vials at times 0.5, 1, 2, 3, 5, 7, 10, 12, 15, 20, 30, 45, and 60 minutes after mixing. Aliquots were withdrawn from 18 vials at 1, 2, 3, 5, 7, and 10 minutes. Free pertechnetate and reduced/hydrolyzed technetium were isolated from aliquots with instant thin-layer chromatography and quantified with a scintillation well counter. Based on the 30 vials, a mean (+/- S.E.M.) of 5.83 +/- 4.32 minutes was required to attain 90% labeling efficiency. Using tolerance limits calculations, the incubation time required to be assured that 95% of vials have achieved 90% labeling is 16.8 minutes. It is concluded that 99mTc iprofenin vials should be incubated 17 minutes to be assured of 90% labeling efficiency.

Imino Acids↗
PubMed1994

[Separation of urological tumor cells by means of a cell saver combined with a membrane filter. A new technique for autotransfusion?].

Three long duration cancer cell lines were marked with radioactive methionine S and mixed with a defined quantity of concentrated red cells. The mixture was separated according to a standardized method with cell saver and two membrane filters. The marked cancer cells were counted with a liquid scintillation cell counter. After separation, only 0.027% of the initial radioactivity was retrieved. If this result can be confirmed in a clinical setting, this technique would be highly promising for intraoperative automatic autotransfusions, especially in the field of tumour surgery. Despite the quality of conserved blood, heterotransfusion still involves considerable risk for the receiver.

Blood Transfusion, Autologous↗
PubMed1999

Polyethylene glycol-modified liposome-encapsulated hemoglobin: a long circulating red cell substitute.

A major obstacle in the development of red cell substitutes has been overcoming their short circulation persistence. In this study, distearoyl phosphoethanolamine polyethylene glycol 5000 (PEG-PE) (10 mol%) was added to the formulation of liposome-encapsulated hemoglobin (LEH) to decrease reticuloendothelial system uptake and prolong LEH circulation persistence. PEG-LEH was radiolabeled with technetium-99m, infused into rabbits (25% of blood pool at 1 ml/min) (n = 5), and monitored by scintigraphic imaging at various times out to 48 h. At 48 h, animals were sacrificed, and tissue samples were collected for counting in a scintillation well counter. Tissue distribution data at 48 h revealed that 51.3 +/- 3.4% of the technetium-99m-PEG-LEH remained in circulation, a greater than 3-fold increase in the circulation half-life compared with circulation half-lives previously reported for non-PEG-containing LEH formulations. The liver had the greatest accumulation at 48 h (12.7 +/- 0.7%), followed by bone marrow (6.2 +/- 0.1%), whereas the spleen had only 1.4 +/- 0.2%. The addition of PEG-PE to the LEH formulation greatly prolongs the circulation persistence of LEH and represents a significant step in the development of red cell substitutes with prolonged oxygen delivery.

Animals↗
PubMedDate not supplied

2003: a centennial of spinthariscope and scintillation counting.

In 1903 W. Crookes demonstrated in England his "spinthariscope" for the visual observation of individual scintillations caused by alpha particles impinging upon a ZnS screen. In contrast to the analogue methods of radiation measurements in that time the spinthariscope was a single-particle counter, being the precursor of scintillation counters since. In the same period F. Giesel, J. Elster and H. Geitel in Germany also found that scintillations from ZnS represent single particle events. This paper summarises the historical events relevant to the advent of scintillation counting.

Journal Article↗
PubMed1977

Performance parameters of the Hamburg 4 pi whole body radioactivity detector.

Large 4 pi whole body counters allow the use of very low doses of radioactivity in medical research and in routine diagnosis of patients. The electronics of the 4 pi whole body counter in Hamburg (HAMCO) have recently been updated. The detector contains 1360 I of liquid organic scintillator. Experiments combined with extensive computer simulations yielded quantitative information for whole body counters and comparable systems, (1) about physical parameters such as detection efficiency, energy resolution and background count rates which are important for practical performance, and (2) concerning the optical properties of the large volume scintillation counters employed here; these are of interest for the construction of future detectors of related types.

Cesium Radioisotopes↗
PubMed2005

Spatial fragment distribution from a therapeutic pencil-like carbon beam in water.

The latest heavy ion therapy tends to require information about the spatial distribution of the quality of radiation in a patient's body in order to make the best use of any potential advantage of swift heavy ions for the therapeutic treatment of a tumour. The deflection of incident particles is described well by Molière's multiple-scattering theory of primary particles; however, the deflection of projectile fragments is not yet thoroughly understood. This paper reports on our investigation of the spatial distribution of fragments produced from a therapeutic carbon beam through nuclear reactions in thick water. A DeltaE-E counter telescope system, composed of a plastic scintillator, a gas-flow proportional counter and a BGO scintillator, was rotated around a water target in order to measure the spatial distribution of the radiation quality. The results revealed that the observed deflection of fragment particles exceeded the multiple scattering effect estimated by Molière's theory. However, the difference can be sufficiently accounted for by considering one term involved in the multiple-scattering formula; this term corresponds to a lateral 'kick' at the point of production of the fragment. This kick is successfully explained as a transfer of the intra-nucleus Fermi momentum of a projectile to the fragment; the extent of the kick obeys the expectation derived from the Goldhaber model.

Carbon↗
PubMed2006

A simple and rapid method for analyzing radon in coastal and ground waters using a radon-in-air monitor.

We have developed a simple and portable technique for measuring moderately high levels of 222Rn (t1/2=3.8d) in natural waters such as coastal water, groundwater, and river water. The water sample is carefully collected in a glass bottle, and the sample bottle is connected to a radon-in-air monitor in a closed air-loop mode. By purging air through the sample, radon is emanated from the water until a chemical equilibration is obtained between the two phases. The radon in the air loop is determined using the radon-in-air monitor. Then, the radon in water is calculated by a radon-partitioning factor between water and air for a measured water temperature. This technique is especially convenient for determination of 222Rn in natural waters on field sites, since it eliminates the preparation of He gas, cold traps, and alpha-scintillation cells and counter, which are required for traditional radon emanation methods.

Air↗
PubMed2006

Standardization of 18F by coincidence and LSC methods.

The nuclide 18F disintegrates to 18O by beta+ emission (96.86%) and electron capture (3.14%) with a half-life of 1.8288 h. It is widely used in nuclear medicine for positron emission tomography (PET). A radioactive solution of this nuclide has been standardized by two techniques: coincidence measurements with a pressurized proportional counter and liquid scintillation counting using the CIEMAT/NIST method. One ampoule containing a solution calibrated in activity was sent for measurement at the International Reference System maintained by the BIPM. Results are in excellent agreement with SIR values.

Calibration↗
PubMed2000

Detecting inflammation with 131I-labeled ornidazole.

The aim of this study was to demonstrate the accumulation of 131I-labeled ornidazole (131I-ORN) in experimental abscesses. 131I-ORN was prepared by electrophilic radioiodination of ORN, using radioiodide in the presence of Iodogen. An in vivo inflammation model was prepared by intramuscular injection of turpentine into the thigh of rabbits. Four days later 131I-ORN was intravenously administered to rabbits. Serial scintigrams were performed at different periods, using a Sophy DX Gamma Camera. 131I-ORN was visualized at 10 min after injection. 131I-ORN was also administered intraperitoneally to rats with turpentine-induced inflammation, for quantitative biodistribution studies. Counts of selected tissues were taken by a NaI(Tl) scintillation detector (gamma counter) after rats were decapitated. The target-to-non-target muscle ratios were 2.5, 2.6, 2.9 and 1.9 at 1, 3, 5 and 24 h, respectively.

Abscess↗