Iodine Profile Research Articles

Subpixel x-ray imaging with an energy-resolving detector.

The detector pixel size can be a severe limitation in x-ray imaging of fine details in the human body. We demonstrate a method of using spectral x-ray measurements to image the spatial distribution of the linear attenuation coefficient on a length scale smaller than one pixel, based on the fact that interfaces parallel to the x-ray beam have a unique spectral response, which distinguishes them from homogeneous materials. We evaluate the method in a simulation study by simulating projection imaging of the border of an iodine insert with [Formula: see text] in a soft tissue phantom. The results show that the projected iodine profile can be recovered with an RMS resolution of 5% to 34% of the pixel size, using an ideal energy-resolving detector. We also validate this method in an experimental study by imaging an iodine insert in a polyethylene phantom using a photon-counting silicon-strip detector. The results show that abrupt and gradual transitions can be distinguished based on the transmitted x-ray spectrum, in good agreement with simulations. The demonstrated method may potentially be used for improving visualization of blood vessel boundaries, e.g., in acute stroke care.

Serum Iodine and Lipid Profile in Patients with Thyroid Diseases

Serum Iodine and Lipid Profile in Patients with Thyroid Diseases

Study of iodine diffusion in silicon carbide

Diffusion of iodine in 6H-SiC and polycrystalline CVD-SiC was investigated using Rutherford backscattering spectroscopy and electron microscopy. A fluence of 1 × 10 16 cm −2 of 127I + was implanted with an energy of 360 keV at room temperature, producing an amorphous surface layer of approximately 220 nm thickness. The implantation profile reached an atomic density of approximately 1.3% at the projected range of about 95 nm. Broadening of the implantation profile and iodine loss through the front surface during isochronal and isothermal vacuum annealing was determined. At a temperature of 1100 °C no iodine loss was observed after 120 h and a diffusion coefficient of less than 10 −21 m 2 s −1 was extracted from the analysis of profile widths. Relatively strong broadening occurred after 60 h annealing at 1200 °C with the iodine profile extending beyond 300 nm into the bulk, accompanied by a surprisingly modest iodine loss through the surface. Electron microscopic studies reveal a drastic restructuring of the surface region at this temperature, indicating possible chemical reactions between iodine and silicon carbide.

Human Serum Protein-Bound iodine and Protein Fractions at Different Physiological and Narcotic States

Iodine profile of Nigerians at different ages in both sexes and in pregnant women, and under narcotic influence, such as alcoholism, cigarette smoking and marijuana addiction were studied. Their serum total protein, albumin and globulin concentrations were also determined. Results of the study showed that serum protein bound iodine levels increased significantly with age in both sexes and in pregnant women, while it decreased significantly in alcoholics, cigarette smokers and marijuana addicts. Serum total protein, albumin and globulin levels increased with age in both sexes and in pregnant women, but were decreased significantly in alcoholics, cigarette smokers and marijuana addicts. Data of the study indicate that serum protein bound iodine levels were potentiated by age, sex and pregnancy, but were impaired by alcoholism, cigarette smoking and marijuana addiction. In addition, serum total protein, albumin and globulin levels were affected by age, sex, pregnancy, cigarette smoking and marijuana addiction. Alcoholism, cigarette smoking and marijuana addiction may have deleterious effects on thyroid function and protein synthesis. NQJHM Vol. 14 (3&4) 2004: pp. 257-261

Applicability of a Model Predicting Iodine-129 Profile in a Silver Nitrate Silica-Gel Column for Dissolver Off-Gas Treatment of Fuel Reprocessing

The applicability of a mathematical model predicting iodine-129 profile in a silver nitrate silica-gel (hereinafter referred to as Ag-S) column for radioactive iodine treatment was examined using actual off-gas from a dissolution step of a spent nuclear fuel reprocessing test rig, where PWR spent fuels with burnups up to 44,000 MWdt−1 were dissolved. The iodine-129 profile predicted by the model showed good agreement with the iodine profile obtained in the experiment. It was suggested that the model would be useful to predict iodine profiles in an Ag-S column operated at 423 K for the off-gas treatment of actual spent fuel dissolution. Also, the values of the parameters used in the prediction, i.e., the effective diffusion coefficient and the Langmuir coefficient, were supposed to be applicable within the volumetric NO2 concentration range lower than 1%.

A Simple Model Predicting Iodine Profile in a Packed Bed of Silica-Gel Impregnated with Silver Nitrate

Based on a simple adsorption theory, a mathematical model was proposed to predict axial iodine profiles of the column of silica gel impregnated with silver nitrate (hereinafter referred to as Ag-S) in an off-gas treatment system for spent fuel dissolution. The unknown parameters of the model: the effective diffusion coefficient Dea and the Langmuir coefficient K were determined by curve fitting of iodine profile experimentally obtained. At 423 K, Dea and K were found to be 5.60×10-7 m2.s-1 and 1.0×105 m3.kg-1, respectively. Using the parameter values, the model could well predict the iodine profiles obtained at 423 K in the previous works under different experimental conditions. Furthermore, the effect of silver contents on the iodine profiles was reasonably predicted. It was suggested that the proposed model is simple and would be useful to predict the iodine profiles in Ag-S adsorbent columns.

A Simple Model Predicting Iodine Profile in a Packed Bed of Silica-Gel Impregnated with Silver Nitrate.

A Simple Model Predicting Iodine Profile in a Packed Bed of Silica-Gel Impregnated with Silver Nitrate.

Retention of iodine in yttria stabilized zirconia

The diffusion behavior of iodine in yttria stabilized zirconia (YSZ) was investigated as a function of the temperature. Iodine implantation was performed in this cubic solid solution by irradiating material samples with 1 MeV iodine ions. The distribution of iodine was evaluated by using TRIM computer calculation and measured by Rutherford backscattering spectrometry (RBS) using 5 MeV 4He particle. The iodine profile was quantified after successive temperature steps. At each step the maximum temperature was held for 2 h. It was found, that the iodine profile remained unchanged up to 1373 K. At 1573 K iodine diffused significantly. The iodine profile was measurable up to 1773 K. Even at this high temperature a significant iodine retention is observed. The diffusion coefficient of iodine (3.5 ± 1.4 × 10 −15 cm 2 s −1) is of the same order as the temperature extrapolated data of iodine in monoclinic/tetragonal zirconia.

Evidence of iodine storage within thyroid stroma after iodine treatment: imaging by secondary ion mass spectometry (SIMS) microscopy in goitrous tissue.

We measured the 127I distribution within tyroid tissue to find out where intrathyroid iodine was deposited during iodine treatment in eight Tunisian female patients (aged 33-58 yr) with endemic euthyroid goiter. Before surgery, five patients were treated during 6 months either by Lugol's solution (group 1: three patients) or by Lugol's and L-thyroxine (group 2: two patients). All patients remained euthyroid during the course of the treatment, which supplied 3.8 mg/day iodine. Three other patients did not receive Lugol's solution (control group). Secondary ion mass spectrometry microscopy was used to map 127-I quantitatively on thyroid sections. Specimens obtained at thyroid surgery were divided macroscopically into nodular and extranodular tissue and chemically fixed to preserve organified iodine. The iodine profile of patients in group 1 did not differ from that in group 2: large amounts of iodine were localized in thyroid follicles and stroma of both nodular and extranodular tissues. In the control group, iodine within stroma was found only in the extranodular tissue. Despite the limited number of patients studied, these data suggest that stromal iodine might represent a storage compartment in times of large iodine supply.

Studies on the diffusion of zinc and iodine into CdTe

Studies on the diffusion of iodine and zinc into CdTe are reported. Each iodine profile was divided up into four distinct regions and described mathematically by a function consisting of the sum of four complementary error functions. When plotted on an Arrhenius graph, the diffusivities gave four straight line relationships with similar slopes and the Arrhenius parameters for the fastest component of D01 = (7 ±3). 10-11 cm2 s-1 and E1 = (0.21 ±0.05) eV. When extrapolated down to 20°C this gave a diffusivity of 10-14 cm2 s-1 indicating that when iodine is diffused from the vapor it is not suitable as a long term stable dopant in devices where sharp impurity profiles are required. In the case of the zinc diffusions, each profile can be divided into two parts and was fitted satisfactorily by the sum of two complementary error functions giving two values of the diffusivities: Dslow due to zinc diffusion into the slice from the vapor and Dfast due to interdiffusion between a surface layer of Znx Cd1-x Te formed on the slice and the remaining CdTe.