• Nuclear Engineering and Technology
• /
• v.10 no.2
• /
• pp.65-72
• /
• 1978

In this paper, it is attempted to investigate the phenomena of iodine stress corrosion cracking of Zircaloy-4 cladding failures in reactor through the results of similar out-of-pile test in iodine vapour. The main result of this experiment is a finding of the relation between the threshold stress which can lead to iodine stress corrosion cracking of Zircaloy-4 tube and the iodine concentration. The values of critical stress and the critical iodine concentration are also obtained. A model which relates failure time of Zircaley-4 tube to failure stress and iodine concentration is suggested as follows: log t$_{F}$ =5.5-(3/2)log$_{c}$-4log $\sigma$ where t$_{F}$ : failure time, minutes c: iodne concentration, mg/㎤ $\sigma$: stress, 10$^4$psi.

• Nuclear Engineering and Technology
• /
• v.55 no.5
• /
• pp.1671-1676
• /
• 2023

The influence of adding iodine as a contrast substance to elevate radiation in a tumor is studied using simulation techniques of Monte-Carlo. The study is carried on a brain cancer by adopting an unsophisticated head phantom. The ionizing radiation source is an external beam of x-rays with energy range of a few tens of keV. The expected radiation dose increment due to adding the iodine is investigated by comparing the radiation in the tumor after and before adding the iodine and calculating the ratio between the two doses. Several concentrations of the contrast substance are used to quantify its impact. The change of the dose increment with the source energy is also examined. It is found that the radiation elevation in the tumor tends to saturate with increasing the iodine concentration, and for the studied domain of energies (30 keV-100 keV), the radiation dose enhancement factors (RDEF) for the different iodine concentrations (1%-9%) show peaked curves, with the peak occurring between 60 keV and 70 keV. For the highest concentration studied, 9%, the peak value is almost 7.

• Korean Journal of Radiology
• /
• v.19 no.6
• /
• pp.1077-1088
• /
• 2018

Objective: To correlate CT parameters on detector-based dual-energy CT enterography (DECTE) with Crohn's disease activity index (CDAI) and externally validate quantitative CT parameters. Materials and Methods: Thirty-nine patients with CD were retrospectively enrolled. Two radiologists reviewed DECTE images by consensus for qualitative and quantitative CT features. CT attenuation and iodine concentration for the diseased bowel were also measured. Univariate statistical tests were used to evaluate whether there was a significant difference in CTE features between remission and active groups, on the basis of the CDAI score. Pearson's correlation test and multiple linear regression analyses were used to assess the correlation between quantitative CT parameters and CDAI. For external validation, an additional 33 consecutive patients were recruited. The correlation and concordance rate were calculated between real and estimated CDAI. Results: There were significant differences between remission and active groups in the bowel enhancement pattern, subjective degree of enhancement, mesenteric fat infiltration, comb sign, and obstruction (p < 0.05). Significant correlations were found between CDAI and quantitative CT parameters, including number of lesions (correlation coefficient, r = 0.573), bowel wall thickness (r = 0.477), iodine concentration (r = 0.744), and relative degree of enhancement (r = 0.541; p < 0.05). Iodine concentration remained the sole independent variable associated with CDAI in multivariate analysis (p = 0.001). The linear regression equation for CDAI (y) and iodine concentration (x) was y = 53.549x + 55.111. For validation patients, a significant correlation (r = 0.925; p < 0.001) and high concordance rate (87.9%, 29/33) were observed between real and estimated CDAIs. Conclusion: Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD.

• Journal of Nutrition and Health
• /
• v.30 no.10
• /
• pp.1195-1202
• /
• 1997

Iodine-rich seaweed soup has been traditionally supplied to postpartum women in Korea. This dietary habit might introduce over-intake of iodine above the recommended requirements, and might provoke postpartum thyroid dysfunction. Although the response to excess iodine intake is highly variable, goiter, hyperthyroidism, hypothyroidism, and thyroiditis could follow the daily intake of 1,500$\mu\textrm{g}$ of iodine. A few studies are available concerning iodine toxicity in Korea. The purpose of this study was to investigate the relationships between the dietary intake of iodine and thyroid function change as well as the incidence of postpartum thyroiditis. One hundred and thirty-seven postpartum women who had experienced normal deliveries were studied. Dietary intake of iodine and excretion concentration of iodine in breast milk and maternal urine were measured . Serum T$_3$, T$_4$, TSH, anti-thyroglobulin antibody, and anti-microsomal antibody were anlayzed 1 week before delivery and 1, 6, 12, and24 weeks after delivery. Iodine intake was analyzed by one-to-one interviews using 24-hr recall and a food frequncy questionnaire. The result showed that the intake of dietary iodine before delivery and 1 and24 weeks after delivery were 483$\mu\textrm{g}$/day, 3367$\mu\textrm{g}$/day, and 1069$\mu\textrm{g}$/day, respectively. The concentration of iodine in urine at the first week after delivery was 63$\mu\textrm{g}$/dL, and 23.9$\mu\textrm{g}$/dL in breast milk . The levels of serum T$_3$ and T$_4$ before delivery were 2.01ng/mL and 11.49$\mu\textrm{g}$U/dL, respectively, showing that the levels were gradually dropping to normal values after delivery. Positive serum anti-thyroglobulin antibody and anti-microsomal antibody appeared in 3 cases. After a 24 week follow-up period , 6 women(10.3%) experienced cases of postpartum thyroiditis, 5 of which were cases of hyperthyroidism and one of which was a case of hypothyroidism. These figures of postpartum thyroiditis are similar to those of other countries.

• Journal of the Korean Society of Radiology
• /
• v.17 no.1
• /
• pp.1-9
• /
• 2023

For optimal image quality of computer tomography angiography (CTA), different iodine concentrations and scan parameters were applied to quantitatively evaluate the image quality characteristics of filtered back projection (FBP), hybrid-iterative reconstruction (hybrid-IR), and deep learning reconstruction (DLR). A 320-row-detector CT scanner scanned a phantom with various iodine concentrations (1.2, 2.9, 4.9, 6.9, 10.4, 14.3, 18.4, and 25.9 mg/mL) located at the edge of a cylindrical water phantom with a diameter of 19 cm. Data obtained using each reconstruction technique was analyzed through noise, coefficient of variation (COV), and root mean square error (RMSE). As the iodine concentration increased, the CT number value increased, but the noise change did not show any special characteristics. COV decreased with increasing iodine concentration for FBP, adaptive iterative dose reduction (AIDR) 3D, and advanced intelligent clear-IQ engine (AiCE) at various tube voltages and tube currents. In addition, when the iodine concentration was low, there was a slight difference in COV between the reconstitution techniques, but there was little difference as the iodine concentration increased. AiCE showed the characteristic that RMSE decreased as the iodine concentration increased but rather increased after a specific concentration (4.9 mg/mL). Therefore, the user will have to consider the characteristics of scan parameters such as tube current and tube voltage as well as iodine concentration according to the reconstruction technique for optimal CTA image acquisition.

• Korean Journal of Veterinary Research
• /
• v.6 no.1
• /
• pp.18-23
• /
• 1966

The protein-bound iodine-131, the concentration of iodine-131 in blood, and the excretion rate of I-131 through urine and feces were observed in nine Korean native goats, 3 months age, following administration of $3{\mu}C$ of I-131 per kg of body weight. No signiant differences were found due to sex and castration. 1. The average protein-bound iodine-131 conversion ratio of goats was 16.7% in 24 hours. In castrated group, the lowest proteinbound iodine-131 conversion ratio was observed. 2. The average concentration of iodine-131 in bleed, increased very rapidly by 2 hours(4.75%) and rapidly decreased within 6 hours(0.73%). 3. The average excretion rate of I-131 through urine was highest in 24 hours(19.00%) and decreased rapidly within 48 hours(5.32%). 4. The average excretion ration rate of I-131 though feces was highest in 24 hours(2.55%), and decreased slowly.

• Journal of Nutrition and Health
• /
• v.54 no.6
• /
• pp.644-663
• /
• 2021

Purpose: This study was conducted to evaluate the safety of iodine intake based on ingestion levels and urinary iodine excretion of women of childbearing age (15-45 years old) using data from the 2013-2015 Korea National Health and Nutrition Examination Survey. Methods: Iodine intake was calculated using the 24 hours dietary recall method and urinary iodine excretion. The iodine nutrition database for the analysis of dietary iodine intake was constructed using the food composition database of the Rural Development Administration (RDA), the Korean Nutrition Society (KNS), the Ministries of Food and Drug Safety, China and, Japan. The World Health Organization (WHO) evaluation criteria and hazard quotient (HQ) calculated using biomonitoring equivalents (BE) were applied to evaluate the safety of the iodine intake. Results: Of the study subjects, 15.22% had a urinary iodine concentration level of less than 100 ㎍/L, which was diagnosed as deficient, and 48.16% had an excessive iodine concentration of over 300 ㎍/L. Urinary iodine concentration was 878.71 ㎍/L, iodine/creatinine was 589.00 ㎍/g, and iodine/creatinine was significantly higher at the age of 30-45 years. The dietary iodine intake was 273.47 ㎍/day, and the iodine intake calculated from the urinary iodine excretion was 1,198.10 ㎍/day. Foods with a high contribution to iodine intake were vegetables, seafood, seaweed and processed foods. The HQ was 1.665 when the urinary iodine content was > 1,000 ㎍/L. Conclusion: The results of this study implicate that the urinary iodine concentration, rather than the dietary iodine intake, is more appropriate to evaluate the iodine status under the current situation that a comprehensive iodine database for Koreans has not been established.

• Journal of Veterinary Clinics
• /
• v.33 no.5
• /
• pp.274-277
• /
• 2016

To determine the concentrations of commercial milks and the effect of different teat dipping methods on iodine concentrations of bulk tank milk, iodine concentration was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The 59 bulk tank milk samples were collected. The 8 brands of commercial whole milk and 5 brands of commercial organic milk were purchased. The iodine concentrations of bulk tank milks of 59 dairy farms were in the range from 42.7 to $562.5{\mu}g/L$. The iodine levels of 4 different teat dipping methods with pre-dipping, post-dipping, pre & post-dipping, and non-dipping were $138.9{\pm}41.1$, $200.6{\pm}106.9$, $205.1{\pm}93.2$, and $110.9{\pm}70.4{\mu}g/L$, respectively. No significant difference (P > 0.05) was observed among 4 different teat dipping methods. Iodine concentrations of commercial whole milks were in the range from 149.1 to $210.4(178.8{\pm}22.0){\mu}g/L$, and iodine concentrations of commercial organic milks were in the range from 85.0 to $356.9(214.2{\pm}123.3){\mu}g/L$. Iodine concentrations of commercial milk in Korea are relatively low comparing with those of other countries.

• Applied Biological Chemistry
• /
• v.19 no.2
• /
• pp.70-74
• /
• 1976

In order to study the mechanism of biosynthesis of thyroid hormones, radioactive iodine was injected into the rats and thyroid glands were removed. Iodine compounds hydrolyzed by pancreatin viokase were separated by paper chromatography and analyzed by radioautography. Radioautograms showed that the uptake of iodine starts immediately and forms diiodotyrosine through monoiodotyrosine. Evidence supported the possibility that diiodotyrosine is a precursor of thyrosine and triiodothyronine is a degradation product of thyroxine. The rat administered propylthiouracil showed inorganic iodine concentration activity, while the binding activity was prevented.

• Journal of Nutrition and Health
• /
• v.31 no.2
• /
• pp.206-212
• /
• 1998

This study was undertaken to analyze the iodine content in commonly donsumed Korean foods. Food samples were purchased from 3 randomly selected markets. The iodine contents in foods were determined by nuetron activation analysis (NAA). All irradiation of food samples were done at a pnueumatic transfer system (thermal nuetron flux : 1 $\times$1013n/$\textrm{cm}^2$.s) of the TRIGA MarkIII research reactor in the Korea Atomic Energy Research Institute . The results indicated that the iodine content was high in seaweeds, fishes, and iodine-enriched eggs in that order and very low in grain, beans , fruits and vegetables. Edible seaweeds contained iodine levels of between 13,700 and 1,790, 600$\mu\textrm{g}$/kg. Levels of iodine in fishes and shellfishes were between 478 and 2, 840$\mu\textrm{g}$/kg. Ordinary eggs contained 314$\mu\textrm{g}$/kg iodine, but iodine -enriched eggs contained 1,869$\mu\textrm{g}$/kg. The average concentration of iodine in milk was 207$\mu\textrm{g}$/kg. There was seasonal variation in the iodine content of milk , levels were highest in winter milk(230$\mu\textrm{g}$/kg) and lowest in summer milk(180$\mu\textrm{g}$/kg).The idodine contents of most vegetables and fruits were below 10$\mu\textrm{g}$/kg. The iodine contents of most vegetables and fruits were below 10$\mu\textrm{g}$/kg. From high to low , the sequence of foods with high iodine content in one serving was as follows ; sea tangle , sea mustard, iodine-enriched eggs, fish , laver and milk. This study may provide basic data on the iodine content of foods consumed by Korean which have not yet been analyzed .