Development and Construction of a Cost-effective PET-like Detector System Oppotsch, J.; Fritsch, M.; Heinsius, F.-H. ...
2023 IEEE Nuclear Science Symposium, Medical Imaging Conference and International Symposium on Room-Temperature Semiconductor Detectors (NSS MIC RTSD),
2023-Nov.-4
Conference Proceeding
In this paper, a cost-effective PET-like detector system is presented. The innovative system consisting of 88 plastic scintillators of 1 m length and customized silicon photomultiplier arrays is ...developed to reduce the overall cost of otherwise very expensive commercial PET scanners. Fully assembled, it spans a volume of about 0.5 x 0.5 x 1 m 3 . Due to the two-sided readout of the scintillator bars, the detector system provides bulk-internal information within large, dense, and even optically opaque systems by combining positron emission particle tracking with time-of-flight measurements. With this capability, it becomes very interesting for many large-scale industrial processes, such as waste incineration or the treatment of bulk solids in process, chemical, pharmaceutical, and food industry. Results of a prototype setup will be presented.
This study examines the differences between youths classified as either delinquent or status offenders in New York. Findings reveal great similarities between the two groups, suggesting that for ...many, the determination of a more severe classification of delinquent or the lesser classification of status offender is more a function of artificial labels than true differences. This study is meant to encourage debate about effectiveness of the classification process and deleterious social outcomes beyond mere recidivism.
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BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, ODKLJ, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Recent data suggest that elevated levels of uric acid (UA) might contribute to the progression of renal disease. Rasburicase, recombinant urate oxidase, is a highly safe and efficacious ...hypo-uricosuric agent for treatment of elevated UA levels from tumor lysis. We adopted the use of rasburicase for management of hyperuricemia in infants with acute kidney injury (AKI) and, herein, report our experience. We conducted a retrospective chart review of infants with hyperuricemia (UA > 8 mg/dl) secondary to AKI (serum creatinine > 1.5 mg/dl) treated with rasburicase. Seven infants (mean age 34 ± 55 days, six male), with a mean weight of 3.2 ± 1.2 kg, were identified. Rasburicase was administered intravenously as a single, onetime, bolus of 0.17 ± 0.04 mg/kg body weight. Within 24 h, serum UA had decreased from 13.6 ± 4.5 mg/dl to 0.9 ± 0.6 mg/dl (
P
< 0.05), creatinine had decreased from 3.2 ± 2.0 mg/dl to 2.0 ± 1.2 mg/dl (
P
< 0.05), and urinary output had increased from 2.4 ± 1.2 ml/kg per hour to 5.9 ± 1.8 ml/kg per hour (
P
< 0.05). Continued improvements in UA, creatinine, and urinary output were observed in the week following administration of rasburicase, without rebound of the UA. We observed no treatment-related side effects. All patients demonstrated a normalization of uric acid level without need of renal replacement therapy. In conclusion, a single intravenously administered bolus of rasburicase appears to be a novel treatment for hyperuricemia in infants with AKI.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Context. The massive Wolf-Rayet type star WR 102c is located near the Quintuplet Cluster, one of the three massive star clusters in the Galactic centre region. Previous studies indicated that WR 102c ...may have a dusty circumstellar nebula and is among the main ionising sources of the Sickle Nebula associated with the Quintuplet Cluster. Aims. The goals of our study are to derive the stellar parameters of WR 102c from the analysis of its spectrum and to investigate its stellar and nebular environment. Methods. We obtained observations with the ESO VLT integral field spectrograph SINFONI in the K-band, extracted the stellar spectra, and analysed them by means of stellar atmosphere models. Results. Our new analysis supersedes the results previously reported for WR 102c. We significantly decrease its bolometric luminosity and hydrogen content. We detect four early OB type stars close to WR 102c. These stars have radial velocities similar to that of WR 102c. We suggest that together with WR 102c these stars belong to a distinct star cluster with a total mass of ~ 1000 M⊙. We identify a new WR nebula around WR 102c in the SINFONI map of the diffuse Brγ emission and in the HST Paα images. The Brγ line at different locations is not significantly broadened and similar to the width of nebular emission elsewhere in the H ii region around WR 102c. Conclusions. The massive star WR 102c located in the Galactic centre region resides in a star cluster containing additional early-type stars. The stellar parameters of WR 102c are typical for hydrogen-free WN6 stars. We identify a nebula surrounding WR 102c that has a morphology similar to other nebulae around hydrogen-free WR stars, and propose that the formation of this nebula is linked to interaction of the fast stellar wind with the matter ejected at a previous evolutionary stage of WR 102c.
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FMFMET, NUK, UL, UM, UPUK
We report the results of an experiment in the Northeast Atlantic in which sulphur hexafluoride (SF sub(6)) was released within an eddy and the behaviour of trace gases, nutrients and productivity ...followed within a Lagrangian framework over a period of 24 days. Measurements were also made in the air above the eddy in order to estimate air-sea exchange rates for some components. The physical, biological and biogeochemical properties of the eddy resemble those of other eddies studied in this area, suggesting that the results we report may be applicable beyond the specific eddy studied. During a period of low wind speed at the start of the experiment, we are able to quantitatively describe and balance the nutrient and carbon budgets for the eddy. We also report concentrations of various trace gases in the region which are similar to those observed in other studies and we estimate exchange rates for several trace gases. We show that the importance of gas exchange over other loss terms varies with time and also varies for the different gases. We show that the various trace gases considered (CO sub(2), dimethyl sulphide (DMS), N sub(2)O, CH sub(4), non-methane-hydrocarbons, methyl bromide, methyl iodide and volatile selenium species) are all influenced by physical and biological processes, but the overall distribution and temporal variability of individual gases are different to one another. A storm disrupted the stratification in the eddy during the experiment, resulting in enhanced nutrient supply to surface waters, enhanced gas exchange rates and a change in plankton community, which we quantify, although overall productivity was little changed. Emphasis is placed on the regularity of storms in the temperate ocean and the importance of these stochastic processes in such systems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We report on the construction of a light pulser monitoring system for the electromagnetic lead tungstate (PbWO4) calorimeter of the future P¯ANDA experiment at FAIR. The system consists of a high ...intensity LED source, an optical fibre distribution system, and a novel and compact continuous light attenuation mechanism based on LCDs allowing operation inside the magnetic field of the P¯ANDA detector. The physics objectives of the P¯ANDA experiment require a highly sophisticated electromagnetic calorimeter covering an energy range spanning more than three orders of magnitude. In order to perform precision measurements with this electromagnetic calorimeter based on lead tungstate crystals in the high-luminosity environment of the P¯ANDA experiment, a frequent monitoring of radiation induced transmittance losses in the crystals on a level of 0.5% is required. This precision can be achieved on a day-by-day basis between regular π0/η invariant mass calibrations, performed at least once a day.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The osmolyte dimethylsulphoniopropionate (DMSP) can be enzymatically cleaved to dimethylsulphide (DMS), acrylate and a proton. The enzyme involved in this reaction is dimethylpropiothetin ...dethiomethylase (DMSP lyase; enzyme classification number 4.4.1.3.). Although the importance of this reaction for the global sulphur cycle, the influence of DMS on atmospheric acidity and the possible effect on climate regulation have been widely recognised, our knowledge of DMSP lyases is limited to just a few studies. Activity measurements of DMSP lyases offer an important step towards a better understanding of the conditions under which DMS is produced. In the available published data somewhat similar methods have been used before, but a critical examination of the method limitations has not been reported. To encourage further research on this enzyme, we suggest and detail two protocols for measurements of DMSP lyase activity: An in vitro assay for crude cell extracts or purified enzyme and an in vivo method for whole cells, which we recently started to use. After addition of DMSP, samples incubated in a gas tight vial may produce DMS from enzymatic cleavage under suitable conditions, and a DMS production rate can be estimated from time-series measurements of DMS in the headspace of the vial. Headspace analysis of DMS is a useful and rapid technique to estimate and compare DMSP lyase activities from different sources. The relative rates of DMS production in the liquid and of the gas transfer between liquid and headspace, determine the rate of DMS production measured via headspace analysis. If DMS production in the liquid is higher than the rate of transfer, headspace measurements will not reflect the actual amount of DMS produced in the liquid. In this case, extracts have to be diluted to a level that ensures linearity between dilution factor and reduction of enzyme activity. Additionally, incubation volumes and vials should be selected to provide a high surface-to-volume ratio to ensure maximum flux of DMS from the aqueous phase into the headspace. The methods can be adapted to further investigate species- and strain-specific activities, biogeographical distribution, cellular location and biochemical properties of various DMSP lyases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The blood substitutes now being developed from molecularly modified hemoglobin interfere with a wide variety of clinical analyzers, but their effects on cooximeters are unknown. Therefore, we ...investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different oximeters and cooximeters: the AVL Omni 6, the AVOXimeters 1000 and 4000, the Ciba Corning (now Bayer) CC270 CO-Oximeter, the Instrumentation Laboratory Synthesis 35, the IL482 and IL682 CO-Oximeters, and the Radiometer OSM3 Hemoximeter. The five blood substitutes in this study were obtained from Apex Bioscience (Research Triangle Park, NC), Baxter Healthcare Corp. (Deerfield, IL), Biopure Corp. (Cambridge, MA), Hemoglobin Therapeutics, and Hemosol, Inc. (Etobicoke, Ontario, Canada). A cooximeter control was used to compare the eight different instruments' measurements on unaltered human hemoglobin. The instruments yielded measurements of total hemoglobin concentration in undiluted blood substitutes that were generally not more variable than those on the control material. By contrast, when compared with readings on controls, the test instruments yielded measurements of the fractional concentrations of oxy-, deoxy-, carboxy-, and methemoglobin that showed greater instrument-to-instrument disparities and larger standard deviations about the all-instrument means. In some cases, the interference was even more obvious: five of six cooximeters gave negative carboxyhemoglobin readings on one particular product. Our findings indicate that the instruments will give less accurate but clinically useful measurements in the presence of these hemoglobin-based blood substitutes.
We investigated the effects of five hemoglobin-based blood substitutes on the measurements of eight different cooximeters. Some blood substitutes caused obvious interference, such as negative carboxyhemoglobin readings; however, the findings indicate that cooximeters will generally give less accurate but clinically useful measurements in the presence of the hemoglobin-based blood substitutes that were tested.
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