scholarly journals Seasonal variation of cesium 134 and cesium 137 in semidomestic reindeer in Norway after the Chernobyl accident

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 35 ◽  
Author(s):  
I.M. H. Eikelmann ◽  
K. Bye ◽  
H. D. Sletten
Keyword(s):  
Seasonal Variation ◽  
Chernobyl Accident ◽  
Whole Body ◽  
Seasonal Differences ◽  
Reindeer Husbandry ◽  
Decrease Rate ◽  
Cesium 137 ◽  
The Mean

The Chernobyl accident had a great impact on the semidomestic reindeer husbandry in central Norway. Seasonal differences in habitat and diet resulted in large variations in observed radiocesium concentrations in reindeer after the Chernobyl accident. In three areas with high values of cesium-134 and cesium-137 in lichens, the main feed for reindeer in winter, reindeer were sampled every second month to monitor the seasonal variation and the decrease rate of the radioactivity. The results are based on measurements of cesium-134 and cesium-137 content in meat and blood and by whole-body monitoring of live animals. In 1987 the increase of radiocesium content in reindeer in Vågå were 4x from August to January. The mean reductions in radiocesium content from the winter 1986/87 to the winter 1987/88 were 32%, 50% and 43% in the areas of Vågå, Østre-Namdal and Lom respectively.

Raciation in Epacris impressa. III. Polymorphic populations

1977 ◽  
Vol 25 (3) ◽  
pp. 325 ◽  
Author(s):  
HM Stace ◽  
YJ Fripp
Keyword(s):  
Population Structure ◽  
Seasonal Variation ◽  
Flowering Time ◽  
Hybrid Origin ◽  
Disruptive Selection ◽  
Seasonal Differences ◽  
The Mean

Polymorphic populations occur throughout most of the distribution of E. impressa Labill., in which pink-flowered plants and white-flowered plants grow intermixed in the same locality. Measurements of corolla lengths indicate that these are panmictic populations: there is no difference between the mean lengths of pink and white corollas. In homogeneous populations (the vast majority) there is no seasonal variation in the flowering times of white-flowered bushes and pink-flowered bushes. At Wilson's Promontory polymorphic scarlet/pink/white populations occur near polymorphic pinklwhite populations and monomorphic scarlet populations. Some of these triple polymorphic populations show heterogeneity of population structure, with seasonal differences of flowering time in the different morphs. Polymorphic populations are generally intermediate between monomorphic populations of the different races of E. impressa. It is likely that they are of hybrid origin. The hypothesis that polymorphic populations form a base for disruptive selection into monomorphic populations is also discussed.

The occurrence and seasonal variation of trace metals in the scallopspecten maximus(L.) andchlamys opercularis(L.)

1973 ◽  
Vol 53 (1) ◽  
pp. 145-166 ◽  
Author(s):  
G. W. Bryan
Keyword(s):  
Seasonal Variation ◽  
Trace Metals ◽  
Biological Indicators ◽  
Whole Body ◽  
English Channel ◽  
Phytoplankton Productivity ◽  
Annual Peak ◽  
The Family ◽  
The Mean ◽  
Autumn And Winter

A comparison has been made between the concentrations of eleven trace metals in the tissues of two species of scallops,Pecten maximus(L.) andChlamys opercularis(L.), collected from the same area of the English Channel. Although there was considerable variation between individual animals, the mean concentrations of Ag, Co, Cr, Cu, Mn, Ni, Pb and Zn were higher in the whole body ofChlamysthan inPectenbut concentrations of Al, Cd and Fe were lower. In both species, seasonal changes in the concentrations of Co, Cu, Fe, Mn, Ni, Pb and Zn were observed and, in general, the highest values were found in the autumn and winter months. These changes may be related to food supply, since concentrations were generally highest when phytoplankton productivity was low and tended to fall in the spring as productivity increased rapidly to its annual peak. Despite problems arising from individual and seasonal variation, the kidneys and digestive gland of scallops appear to have potential as biological indicators of trace metals.The results obtained forPectenandChlamysare compared with those in the literature for species from the family Pectinidae.

A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

1974 ◽  
Vol 13 (02) ◽  
pp. 193-206
Author(s):  
L. Conte ◽  
L. Mombelli ◽  
A. Vanoli
Keyword(s):  
Nuclear Medicine ◽  
Close Agreement ◽  
Whole Body ◽  
Simple Method ◽  
Rapid Estimation ◽  
Absorbed Doses ◽  
The Mean ◽  
The Individual ◽  
Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

Aktivitätskonzentration der vom Personal einer Radiojodtherapiestation eingeatmeten Luft

1987 ◽  
Vol 26 (03) ◽  
pp. 143-146 ◽  
Author(s):  
H. Fill ◽  
M. Oberladstätter ◽  
J. W. Krzesniak
Keyword(s):  
Nuclear Medicine ◽  
Length Of Stay ◽  
Activity Concentration ◽  
Threshold Value ◽  
Whole Body ◽  
Therapeutic Activity ◽  
External Radiation ◽  
Oral Application ◽  
Exhaled Air ◽  
The Mean

The mean activity concentration of1311 during inhalation by the nuclear medicine personnel was measured at therapeutic activity applications of 22 GBq (600 mCi) per week. The activity concentration reached its maximum in the exhaled air of the patients 2.5 to 4 hours after oral application. The normalized maximum was between 2 • 10−5 and 2 • 10−3 Bq-m−3 per administered Bq. The mean activity concentration of1311 inhaled by the personnel was 28 to 1300 Bq-m−3 (0.8 to 35 nCi-rrf−3). From this the1311 uptake per year was estimated to be 30 to 400 kBq/a (x̄ = 250, SD = 50%). The maximum permitted uptake from air per year is, according to the German and Austrian radiation protection ordinances 22/21 µiCi/a (= 8 • 105 Bq/a). At maximum 50% and, on the average, 30% of this threshold value are reached. The length of stay of the personnel in the patient rooms is already now limited to such an extent that 10% of the maximum permissible whole-body dose for external radiation is not exceeded. Therefore, increased attention should be paid also to radiation exposure by inhalation.

scholarly journals Kinetic analysis and optimisation of 18F-rhPSMA-7.3 PET imaging of prostate cancer

2021 ◽  
Author(s):  
Simona Malaspina ◽  
Vesa Oikonen ◽  
Anna Kuisma ◽  
Otto Ettala ◽  
Kalle Mattila ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Metastatic Disease ◽  
Uptake Kinetics ◽  
Whole Body ◽  
Target Area ◽  
Post Injection ◽  
The Mean ◽  
Pet Radiopharmaceutical ◽  
Time Frames ◽  
Over Time

Abstract Purpose This phase 1 open-label study evaluated the uptake kinetics of a novel theranostic PET radiopharmaceutical, 18F-rhPSMA-7.3, to optimise its use for imaging of prostate cancer. Methods Nine men, three with high-risk localised prostate cancer, three with treatment-naïve hormone-sensitive metastatic disease and three with castration-resistant metastatic disease, underwent dynamic 45-min PET scanning of a target area immediately post-injection of 300 MBq 18F-rhPSMA-7.3, followed by two whole-body PET/CT scans acquired from 60 and 90 min post-injection. Volumes of interest (VoIs) corresponding to prostate cancer lesions and reference tissues were recorded. Standardised uptake values (SUV) and lesion-to-reference ratios were calculated for 3 time frames: 35–45, 60–88 and 90–118 min. Net influx rates (Ki) were calculated using Patlak plots. Results Altogether, 44 lesions from the target area were identified. Optimal visual lesion detection started 60 min post-injection. The 18F-rhPSMA-7.3 signal from prostate cancer lesions increased over time, while reference tissue signals remained stable or decreased. The mean (SD) SUV (g/mL) at the 3 time frames were 8.4 (5.6), 10.1 (7) and 10.6 (7.5), respectively, for prostate lesions, 11.2 (4.3), 13 (4.8) and 14 (5.2) for lymph node metastases, and 4.6 (2.6), 5.7 (3.1) and 6.4 (3.5) for bone metastases. The mean (SD) lesion-to-reference ratio increases from the earliest to the 2 later time frames were 40% (10) and 59% (9), respectively, for the prostate, 65% (27) and 125% (47) for metastatic lymph nodes and 25% (19) and 32% (30) for bone lesions. Patlak plots from lesion VoIs signified almost irreversible uptake kinetics. Ki, SUV and lesion-to-reference ratio estimates showed good agreement. Conclusion 18F-rhPSMA-7.3 uptake in prostate cancer lesions was high. Lesion-to-background ratios increased over time, with optimal visual detection starting from 60 min post-injection. Thus, 18F-rhPSMA-7.3 emerges as a very promising PET radiopharmaceutical for diagnostic imaging of prostate cancer. Trial Registration NCT03995888 (24 June 2019).

scholarly journals Improved PET/MRI attenuation correction in the pelvic region using a statistical decomposition method on T2-weighted images

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Elin Wallstén ◽  
Jan Axelsson ◽  
Joakim Jonsson ◽  
Camilla Thellenberg Karlsson ◽  
Tufve Nyholm ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Research Study ◽  
Standardized Uptake Value ◽  
Ground Truth ◽  
Whole Body ◽  
Mr Images ◽  
Pelvic Region ◽  
Mri Scans ◽  
The Mean ◽  
Prostate Cancer Research

Abstract Background Attenuation correction of PET/MRI is a remaining problem for whole-body PET/MRI. The statistical decomposition algorithm (SDA) is a probabilistic atlas-based method that calculates synthetic CTs from T2-weighted MRI scans. In this study, we evaluated the application of SDA for attenuation correction of PET images in the pelvic region. Materials and method Twelve patients were retrospectively selected from an ongoing prostate cancer research study. The patients had same-day scans of [11C]acetate PET/MRI and CT. The CT images were non-rigidly registered to the PET/MRI geometry, and PET images were reconstructed with attenuation correction employing CT, SDA-generated CT, and the built-in Dixon sequence-based method of the scanner. The PET images reconstructed using CT-based attenuation correction were used as ground truth. Results The mean whole-image PET uptake error was reduced from − 5.4% for Dixon-PET to − 0.9% for SDA-PET. The prostate standardized uptake value (SUV) quantification error was significantly reduced from − 5.6% for Dixon-PET to − 2.3% for SDA-PET. Conclusion Attenuation correction with SDA improves quantification of PET/MR images in the pelvic region compared to the Dixon-based method.

scholarly journals A Multi-Channel Uncertainty-Aware Multi-Resolution Network for MR to CT Synthesis

2021 ◽  
Vol 11 (4) ◽  
pp. 1667
Author(s):  
Kerstin Klaser ◽  
Pedro Borges ◽  
Richard Shaw ◽  
Marta Ranzini ◽  
Marc Modat ◽  
...  
Keyword(s):  
Medical Image Analysis ◽  
Absolute Error ◽  
Magnetic Resonance Images ◽  
The Body ◽  
Whole Body ◽  
Image Size ◽  
Body Images ◽  
Image Translation ◽  
The Mean ◽  
Synthetic Ct

Synthesising computed tomography (CT) images from magnetic resonance images (MRI) plays an important role in the field of medical image analysis, both for quantification and diagnostic purposes. Convolutional neural networks (CNNs) have achieved state-of-the-art results in image-to-image translation for brain applications. However, synthesising whole-body images remains largely uncharted territory, involving many challenges, including large image size and limited field of view, complex spatial context, and anatomical differences between images acquired at different times. We propose the use of an uncertainty-aware multi-channel multi-resolution 3D cascade network specifically aiming for whole-body MR to CT synthesis. The Mean Absolute Error on the synthetic CT generated with the MultiResunc network (73.90 HU) is compared to multiple baseline CNNs like 3D U-Net (92.89 HU), HighRes3DNet (89.05 HU) and deep boosted regression (77.58 HU) and shows superior synthesis performance. We ultimately exploit the extrapolation properties of the MultiRes networks on sub-regions of the body.

Analysis of the breeding records of a herd of pigs

1954 ◽  
Vol 45 (1) ◽  
pp. 19-27 ◽  
Author(s):  
R. Braude ◽  
P. M. Clarke ◽  
K. G. Mitchell
Keyword(s):  
Statistical Analysis ◽  
Large White ◽  
Seasonal Differences ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Length Of Gestation

1. A survey and. statistical analysis of the records of litters born in the N.I.R.D. herd of Large White pigs over a period of 16 years are presented.2. The mean length of gestation was 114 days for both gilts and sows.3. The mean numbers of pigs born alive and born dead per litter from gilts, 10·0 and 0·2 respectively, were both significantly smaller than the corresponding figures for sows, 11·8 and O·8. No seasonal differences were found.4. The mean total losses of pigs from birth to weaning at 8 weeks were 29·5% of pigs born alive. The losses in litters from gilts, 23·0%, were significantly smaller than in litters from sows, 31·0%. The losses during the winter months both for gilts, 32·5%, and for sows, 35·9%, were significantly higher than during the summer months, 19·4% and 26·7% for gilts and sows respectively.5. Over 50% of the total losses were due to crushing by the dam, 74·1% of the losses from this cause occurring during the first 48 hr. after birth.6. The mean number of pigs weaned per litter was 8·0. The difference between the number weaned per litter from gilts, 7·7, and per litter from number of pigs was weaned per litter from sows during the summer months, 8·7, than during the winter months, 7·4.7. There was no significant difference between the number of male and of female pigs weaned.8. The mean weight at weaning was 29·9 lb., male pigs, 30·3 lb., being significantly heavier than females, 29·51b. Pigs in litters from gilts, 27·81b., were significantly lighter at weaning than those from sows, 30·0 lb., and for both gilts and sows, pigs reared during the summer months, 29·7 and 31·8 lb. respectively, were significantly heavier than those reared during the winter months, 25·9 and 28·2 lb. respectively.

Safety and feasibility of rhenium-186 nanoliposome (186RNL) in recurrent glioma: The ReSPECT phase 1 trial.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 2061-2061
Author(s):  
Andrew J. Brenner ◽  
Ande Bao ◽  
William Phillips ◽  
Gregory Stein ◽  
Vibhudutta Awasthi ◽  
...  
Keyword(s):  
Dose Escalation ◽  
Tumor Volume ◽  
Phase 1 ◽  
Absorbed Dose ◽  
External Beam Radiation ◽  
Whole Body ◽  
Recurrent Glioma ◽  
Normal Brain ◽  
Beam Radiation ◽  
The Mean

2061 Background: While external beam radiation therapy (EBRT) remains a central component of the management of primary brain tumors, it is limited by tolerance of the surrounding normal brain tissue. Rhenium-186 NanoLiposome (186RNL) permits the delivery of beta-emitting radiation of high specific activity with excellent retention in the tumor. We report the results of the phase 1 study in recurrent glioma. Methods: A Phase 1 dose-escalation study of 186RNL in recurrent glioma utilizing a standard 3+3 design was undertaken to determine the maximum tolerated dose of 186RNL. 186RNL is administered by convection enhanced delivery (CED). Infusion is followed under whole body planar imaging and SPECT/CT. Repeat SPECT/CT imaging is performed immediately following, and at 1, 3, 5, and 8 days after 186RNL infusion to obtain dosimetry and distribution. Subjects were followed until disease progression by RANO criteria. Results: Eighteen subjects were treated across 6 cohorts. The mean tumor volume was 9.4 mL (range 1.1 – 23.4). The infused dose ranged from 1.0 mCi to 22.3 mCi and the volume of infusate ranged from 0.66 mL to 8.80 mL. From 1 – 4 CED catheters were used. The maximum catheter flow rate was 15 µl/min. The mean absorbed dose to the tumor volume was 239 Gy (CI 141 – 337; range 9 - 593), to normal brain was 0.72 Gy (CI 0.34 – 1.09; range 0.005 – 2.73), and to total body was 0.07 Gy (CI 0.04 – 0.10; range 0.001 – 0.23). The mean absorbed dose to the tumor volume when the percent tumor volume in the treatment volume was 75% or greater (n = 10) was 392 Gy (CI 306 – 478; range 143 – 593). Scalp discomfort and tenderness related to the surgical procedure did occur in 3 subjects. The therapy has been well tolerated, no dose-limiting toxicity has been observed, and no treatment-related serious adverse events have occurred despite markedly higher absorbed doses typically delivered by EBRT in patients with prior treatment. Responses have been observed supporting the clinical activity. Final results from the dose escalation will be presented. Conclusions: 186RNL administered by CED to patients with recurrent glioma results in a much higher absorbed dose of radiation to the tumor compared to EBRT without significant toxicity. The recommended Phase 2 dose is 22.3 mCi in 8.8 mL of infusate. Clinical trial information: NCT01906385. [Table: see text]

Seasonal Variation in Acute Dacriocystitis

2021 ◽  
Author(s):  
Elif Ertan ◽  
Sibel İnan ◽  
İsmet Doğan ◽  
Ümit Übeyt İnan
Keyword(s):  
Seasonal Variation ◽  
Outpatient Clinic ◽  
Clinical Picture ◽  
Infectious Agents ◽  
Lacrimal Duct ◽  
Rayleigh Test ◽  
Lacrimal Duct Obstruction ◽  
Duct Obstruction ◽  
The Mean

Abstract Objectives: Seasonal variation is possible in some medical conditions.Acute dacryocystitis is very disturbing clinical picture and can develop in any time of the year in patients with lacrimal duct obstruction. We aimed to investigate whether there is a seasonal relationship with the emergence of acute dacryocystitis.Material and Methods:The files of the patients who applied to the ophthalmology outpatient clinic with the complaints of tearing and discharge for five years and diagnosed with acute dacryocystitis were analyzed retrospectively. Age, gender, date of occurrence of the complaints and the date of diagnosis of acute dacryocystitis were recorded. In order to determine the seasonal relationship, the data regarding the number of cases who applied every month of the year were analyzed statistically by Rayleigh test.Results: The mean age of 60 patients (45 females, 15 males) included in the study was 54.70 ± 16.80 years. It was found that all patients were not equally likely to arrive at the hospital and the onset of their complaints throughout the months of the year (p <0.05). The frequency of applications was higher between May and August.Conclusion: There seems to be a seasonal relationship with the timing of the acute dacryocystitis. In our series, more acute dacryocystitis cases were encountered in the first spring-summer months. The reason for the increase of acute dacryocystitis cases in hot seasons of the year may be due to the increase in infectious agents in these seasons.

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