The entry of strontium-90 into human bone

For 6 years human bones, mostly femora, have been analyzed for strontium-90 by radio-chemical methods and for natural strontium spectrographically. The mean concentrations relative to calcium (pc/g Ca and μ g/g Ca) are charted according to age. In each year the peak value for 90 Sr was in juveniles aged 1 to 2 years; it increased progressively in 1956–59 and fell in 1960–61. Values for the newborn which are dependent on maternal plasma and on domicile of mother moved similarly with time. By contrast values for bones of adolescents and adults increased progressively. The concentration was substantially uniform between bones in infants and children. In adults cancellous bones especially vertebrae gave higher concentration than ivory bones. The mean values for stable strontium for the six-year period were ~ 200 μ g/g Ca from birth till 6 months of age; they then rose sharply in the next year and later more slowly to 330 μ g/g Ca in adults. It is deduced (1) that the discrimination between Ca and Sr across the human placenta is nearly twofold, (2) that in the first year of the infant’s life the discriminatory processes especially in absorption observed in the human adult are not fully developed, (3) that by considering the specific activity ( 90 Sr/mg Sr) of bone in children according to cohort, bone turnover must be nearly complete in each of the first few years of life whereas in adolescents accretion of new salt is the preponderant factor, (4) and that in the adult where growth has ceased the relative annual ‘rates of replacement’ of existing mineral by new mineral from diet vary about 2% for ivory bone to 8% for vertebrae.

PEDIATRICS ◽  
1964 ◽  
Vol 33 (4) ◽  
pp. 507-511
Author(s):  
Yehuda Matoth ◽  
Ariela Pinkas ◽  
Rina Zamir ◽  
Fouad Mooallem ◽  
Nathan Grossowicz

The level of folic and folinic acid in whole blood was assayed in 373 healthy infants from birth to one year. Folic acid was high at birth and dropped gradually over the first 8 postnatal weeks. The mean value for the remainder of the first year was significantly below the adult mean. Folinic acid was likewise high at birth and dropped parallel with the folic acid. However, following the initial drop, folinic acid mean values remained well above the adult mean. Folic and folinic acid values were higher in breast-fed than in artificially fed infants and lower in infants whose economic status was poor than in babies belonging to families of higher income.


1988 ◽  
Vol 117 (2) ◽  
pp. 219-224 ◽  
Author(s):  
J. Date ◽  
M. Blichert-Toft ◽  
U. Feldt-Rasmussen ◽  
V. Haas

Abstract. The effect of subtotal thyroid resection for thyrotoxicosis on concentrations of serum thyroid hormones and thyroglobulin (Tg), was determined in 10 patients during operation and the subsequent 18 days. Mean serum Tg responded drastically, increasing from a pre-operative value of 0.30 nmol/l to a peak value of approximately 26 nmol/l during operation followed by a gradual decline to levels lower than before surgery on day 18. Mean serum total thyroxine was 114 nmol/l pre-operatively and free thyroxine index (FT4I) 105 units. Both fluctuated only slightly during operation. Postsurgically, the mean values decreased to below 50% of the pre-operative level. Mean serum total triiodothyronine (TT3) was 1.46 nmol/l pre-operatively. It decreased during operation, reaching a nadir of 0.55 nmol/l on day 2, whereafter the concentration increased slightly. Mean serum reverse T3 (rT3) was 0.45 nmol/l pre-operatively, increased 62% during surgery, and decreased postsurgically. The mean value of serum thyroid stimulating hormone (TSH) was 0.61 mU/l pre-operatively and remained below 1 mU/l during and after operation, but from day 10 concentration began to rise steadily. It is concluded that the vast release of Tg during thyroid resection did not contribute to the concentration of serum T4 to an extent of clinical relevance.


Author(s):  
Henrique A. de Souza ◽  
Roberto C. F. F. Pompeu ◽  
Rafael G. Tonucci ◽  
Francisco E. P. Fernandes ◽  
Maria D. M. Araújo ◽  
...  

ABSTRACT The use of organic fertilizers can increase the production of forest species for the extraction of wood from monoculture stands or integrated systems. This study aimed to evaluate the effect of applying doses of sheep manure on the biometric traits of Mimosa caesalpiniifolia (‘sabiá’) in a silviculture system in an area previously occupied by native degraded pasture in an Albaquult. The experimental design was randomized blocks with four repetitions, with treatments corresponding to five doses of sheep manure per plant: 0, 2, 4, 8, and 12 kg in the first year, while in the second year the double of the doses (0, 4, 8, 16 and 32 kg per plant) were applied as topdressing under the canopy. The following biometric variables were evaluated: height (H); root collar diameter (RCD); diameter at breast height (DBH); above-ground dry weight (AGDW); accumulation of nutrients (aerial part); and soil fertility. The plants were responsive to the organic fertilization regarding the variables H, DBH, and AGDW. The sheep manure increased the mean values of pH, P, K, Ca, Mg, SB, CEC, BS, S-SO4 2- and Zn, and reduced the potential acidity in the 0-0.20 m soil layer. The organic matter variable increased up to the dose of 13.70 kg per plant. The accumulation rates of macro and micronutrients in the ‘sabiá’ plants were N > Ca > K > Mg > P > S and Fe > Mn > B > Zn > Cu, respectively.


2020 ◽  
Vol 11 (5) ◽  
pp. 8-11
Author(s):  
Jitendra Sorout ◽  
Satyanath Reddy Kodidala ◽  
Harsha Soni ◽  
Priyanka Singh ◽  
Nirmal Sharma

Background: Newly admitted medical students experience a different curriculum, which can be a stressor and may be the reason of stress during student life. Stress may affect physiological, psychological and cognitive functions of the students. Aims and Objective: Aim of the study was to assess the effect of academic stress on physical activity level and cognitive functions in first year medical students. Materials and Methods: This observational study was conducted on 30 healthy newly admitted medical students (18 -25 years). The data was collected thrice, baseline, after two months and after four months. Stress was assessed by using DASS and Cohen perceived stress scale (PSS). GPAQ was used to estimate the physical activity level. And cognitive functions were assessed by using subjective method (MMSE questionnaire) and objective method (P300). Results: No significant difference of mean values of age, height, weight, BMI, physical activity level, DASS score, PSS and P300 latency were observed over the time to which recording was taken. The mean score of PAL represents the high physical activity. But the score of DASS and PSS represent severe and moderate stress level respectively. The significant difference was seen in the mean values of MMSE score and P300 amplitude over the time to which recording taken. Conclusion: The present study results we can conclude that students have stress during their academic period. And this stress might be helpful in potentiating the cognitive functions with the optimum physical activity.


2021 ◽  
Vol 14 (2) ◽  
pp. 177-191

Abstract: Radioactivity must be studied in soil to see the changes in the doses of human exposure. In this study, natural radioactivity and radiological hazard indices in soil samples of the Faculty of Agriculture (Al-Husseineya site) and the Faculty of Medicine (Al-Mothafeen site) in Kerbala Governorate were determined using gamma-ray spectroscopy. The results showed that the mean values of specific activity (in units of Bq/kg) and standard errors of: 238U, 232Th and 40K at Al-Husseineya site was 21.7±7.2, 9.43±3.2 and 335.8±82.2, respectively, while at Al-Mothafeen site, the mean values and standard errors were 22.4±8.8, 11.2±3.3 and 333.1±70.7, respectively. Radiation maps of natural radioactivity (238U, 232Th and 40K) at Al-Husseineya and Al-Mothafeen sites were mapped using geographic information system (GIS) technology. Moreover, most results in the present study fall within the acceptable levels, as defined by OCDE, UNSCEAR and ICRP. Therefore, there is no significant radiological hazard at the sites which were studied. Keywords: Radiological hazard, Natural radioactivity, Soil, NaI (Tl), Gamma-ray, Karbela University.


2010 ◽  
Vol 79 (9) ◽  
pp. S85-S91 ◽  
Author(s):  
Petr Dvořák ◽  
Petr Snášel ◽  
Katarína Beňová

The aim of the study was to find the sources of 137Cs in wild boar food in the natural ecosystem. The main emphasis is focused on the analyses of wild boar muscles and the content of wild boar stomach. Boars weighing 20 to 100 kg were killed at two locations. The highest specific activities of muscles were measured in boars originated from the Dvorce location; the average specific activity in boars killed on 14 April 2007 and 9 March 2008 achieved 132 Bq kg-1. Due to high fluctuation the differences between the mean values of 31 Bq kg-1 in males and 43 Bq kg-1 in females were not significant. Earthworms from grass fields with a specific activity of 16 Bq kg-1, rootlets from the Šabrava location with 200 Bq kg-1 and Elaphomyces granulatus fruiting bodies with 4,743 Bq kg-1 and 2,858 Bq kg-1 are the components of boar food with the 137Cs specific activities higher than that of the detection limit. Consequently, underground mushrooms probably represent the main source of radiocesium in the food chain of boars. A remarkable reduction of 137Cs specific activities in boar muscles is not expected at the post-Chernobyl radiocesium contaminated locations with the occurrence of Elaphomyces granulatus within next two decades.


2019 ◽  
Vol 83 (03) ◽  
pp. 473-478
Author(s):  
Joel D. Grice ◽  
Aaron J. Lussier ◽  
Henrik Friis ◽  
Ralph Rowe ◽  
Glenn G. Poirier ◽  
...  

AbstractSchizolite, originating from the type locality, Tutop Agtakôrfia, in the Ilímaussaq alkaline complex, Julianehåb district, South Greenland, was described initially by Winther (1901) with additional data being supplied by Bøggild (1903). Recently, a proposal for the new mineral ‘marshallsussmanite’ was submitted to, and approved by, the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2013-067) by Origlieri et al. (2013). Results from the detailed examination of two schizolite cotype samples presented here, using single-crystal and powder X-ray diffraction, and optical properties, confirms it to be equivalent to ‘marshallsussmanite’. Historical precedence sets a priority for discrediting the name ‘marshallsussmanite’ in favour of the original, more-than-a century-old name, schizolite. The two schizolite samples investigated vary slightly in physical and chemical properties but are consistent overall. The prismatic crystals are pale red or pink to brownish. Schizolite is brittle with a splintery aspect. It is biaxial (+), with average optical parameters: α = 1.626 ± 0.003, β = 1.630 ± 0.002, γ = 1.661 ± 0.002, 2Vmeas = 71(4)° and 2Vcalc = 40°; there is no pleochroism. Electron microprobe analysis shows both samples have nearly identical compositions (differences <0.4 wt.% oxide), with the mean values of: SiO2 52.6(4); Al2O3 0.005(1); FeO 2.54(2); MnO 13.86(9); CaO 17.9(4); Na2O 8.9(1); and H2O 2.59(2) wt.% oxide; this corresponds to a mean formula of: Na1.00(2)Ca1.11(7)Mn0.68(1)Fe0.12(0)Si3.041(1)O8(OH). Final least-squares structure refinements for both samples converged at R1 values ≤2.0%; H atoms were located in all refinements.


2021 ◽  
Author(s):  
Mekuanint Lemlem Legasu ◽  
Ashok K Chaubey

Abstract Background & Methodology : The specific activity concentration of naturally occurring radionuclides 226Ra, 232Th, 40K and their health related effects were determined in different environmental samples(gemstones) collected from Delanta-Dawunt. Which is one of the mining place in Ethiopia to extract mainly opals (gemstones). Sample collection and the gamma spectroscopic analysis followed the recommended international procedures for such type of research. Gamma-ray spectrometry was applied using HPGe gamma-ray detector and PC-based MCA. The Purpose of this research: to determine the activity concentrations of the radionuclides U/Th series and K of gemstones(opals), to determine life time cancer risk of radionuclide in the environment , to assess the hazard and risk to the public associated with these dose values , to conduct the geochemical studies by quantifying the levels of trace gemstones as well as the physical parameters in soil samples within and around it, and To determine the radiation doses from these activity concentrations and compare with international recommended dose limits. Results: The results of the activity concentration on our research work showed significant variations from 11.97 ± 2.46 to 62.44 ± 14.99 Bq kg-1 for 226Ra, 25.69 ± 3.69 to 137.84 ± 13.23 Bq kg-1 for 232Th and 184.84 ± 3.59 to 969.56 ±18.16 Bq kg-1 for 40K. The mean radioactivity concentration of 226Ra, 232Th, and 40K was found to be around 29.84 ± 6.53, 68.44 ± 18.94, 390.87 ± 6.09 Bk kg-1 respectively. Conculsion: The mean values of Radium equivalent activity (Raeq), absorbed dose, annual effective dose equivalent, external and internal radiation hazard (Hex and Hin) index ,and activity utilization index is 151.68±19.46 Bq kg-1, 72.19 ± 8.48 nGy h-1, 0.07 ± 0.01mSv y-1,0.43, 0.51, 0.57 ± 0.08 and 0.29 ± 0.03 respectively. The specific activity of 232Th is higher than the world mean value and 40K is the same as the world mean value. The radiation hazard indices, ELCR values found in this study are lower than the world mean values. However, the absorbed dose is higher than the world means value. This is due to the reason of high thorium concentration existence and opal mining is highly explored on such study areas.


1968 ◽  
Vol 51 (4) ◽  
pp. 828-834
Author(s):  
Omer Pelletier

Abstract The AOAC method and the Pelletier and Campbell method for the assay of niacinamide in multivitamin preparations were compared in two collaborative studies. In the first study, three multivitamin sirup preparations were analyzed by six laboratories; the proposed method gave higher results for two preparations but lower results for the third. In the second study, four types of multivitamin preparations were analyzed; twelve laboratories reported on the chemical methods and three laboratories on the microbiological method. There was no difference in the mean values for two types of samples, but one sample of multivitamin tablets yielded mean values about 5% lower by the proposed method, suggesting the presence of a trace of niacin; with a multivitamin and mineral sirup the proposed method gave values about 6% higher than the AOAC method and 3% lower than the microbiological assay. The coefficient of variation for any sample in any laboratory by the AOAC method was about 14% in the first study and 1 1% in the second study; by the proposed method it was 4 and 9% in the same respective studies. It is recommended that the present AOAC method be modified by adjusting the pH of sample hydrolysates in the range of 2.5—4.5 instead of 7—9 to reduce the absorhance of the blanks, and that the method of Pelletier and Campbell be adopted as official, first action.


1930 ◽  
Vol 52 (2) ◽  
pp. 145-166 ◽  
Author(s):  
Louise Pearce ◽  
Albert E. Casey

Consecutive weekly observations on the neutrophile, the basophile, and the eosinophile counts of the peripheral blood were made on 5 groups of normal rabbits, a total of 45 animals, during a period of 20 months from October, 1927 to July, 1929. Individual groups were examined 8 to 35 weeks. In the case of the 4 groups followed 13 to 35 weeks, the general trend of the neutrophile cells was towards increased mean values; with the group followed 8 weeks, decreasing values were found. An increase in the mean values of the basophile cells was observed in the two groups of rabbits followed in 1927–28; in the groups of 1928–29, the mean values decreased. The mean values of the eosinophile cells showed no definite trends but the findings were characterized by abrupt and marked fluctuations. The periods of greatest irregularity in mean neutrophile and eosinophile values occurred in the fall and the late winter and spring months of both years, but in the case of the basophiles, the irregularities were distributed throughout the first year and occurred chiefly in the winter months of the second year. The major trends and many of the minor fluctuations as well which were observed in the mean cell values of one group of rabbits were also generally seen in another group examined during the same months. The general levels of the neutrophile, the basophile, and the eosinophile mean values in the groups examined during 1927–28 were higher than in the groups of 1928–29.


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