• Journal of Acupuncture Research
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• v.15 no.2
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• pp.43-60
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• 1998

This study examined the histomorphomeric and histological changes of the left and right kidney in uninephrectomized rat. The results were as follows: 1. In the control, the right kidney was more prominent than the left in the basement membrane of glomerular capillaries. The podocyte had well developed Golgi apparatus in the left kidney and rough endoplasmic reticulum in the right kidney. 2. At the 30 days after unilateral nephrectomy, the basal lamina of glomerular capillaries was prominently thickened in the right kidney. The cytoplasm of the podocyte of the left kidney was markedly increased and had free ribosomes, developed Golgi apparatus and rough endoplasmic reticulum. 3. At the 30 days, the section of the glomeruli were more enlarged in the left kidney than in the right. 4. At the 20 day, the nuclear section of the podocytes were markedly enlarged in the right kidney, but those of the left kidney were diminished. The mitochondrial section of the podocytes were prominently increased in the right kidney. 5. The nuclear section of the parietal layer lining cells was no significant change in the right kidney. That of the left kidney was increased at the 20 days and decreased at the 40 days. The nuclear section of glomerular endothelium of the left kidney increased earlier than the right. 6. In the morphometry of the control kidney, the section areas, long and short diameters, the nuclear section, the mitochondrial section of the proximal tubule cells, and the changes of those were more large in the right kidney than in the left. 7. The luminal secretory vesicles and peroxisomes of the left kidney were more than the right at the 20 days. The increase of mitochodrial section in the proximal tubule cells of the left kidney was more prominent than the right. The large cytoplasmic vacuoles were more prominent in the left kidney than in the right. 8. The thickness of cytoplasm and brush border was more thick in the control left kidney than in the control right. The change of cytoplasmic thickness of the left kidney was increased earlier than in the right and both kineys were increased in the thickness of brush border at the 30 days.

• Progress in Medical Physics
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• v.20 no.1
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• pp.7-13
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• 2009

This work is for the preliminary study for the calibration of an $^{192}Ir$ brachytherapy source based on an absorbed dose to water standards. In order to calibrate brachytherapy sources based on absorbed dose to water standards using a clyndirical ionization chamber, the beam quality correction factor $k_{Q,Q_0}$ is needed. In this study $k_{Q,Q_0}s$ were determined by both Monte carlo simulation and semiexperimental methods because of the realistic difficulties to use primary standards to measure an absolute dose at a specified distance. The 5 different serial numbers of the PTW30013 chamber type were selected for this study. While chamber to chamber variations ran up to maximum 4.0% with the generic $k^{gen}_{Q,Q_0}$, the chamber to chamber variations were within a maximum deviation of 0.5% with the individual $k^{ind}_{Q,Q_0}$. The results show why and how important ionization chambers must be calibrated individually for the calibration of $^{192}Ir$ brachytherapy sources based on absorbed dose to water standards. We hope that in the near future users will be able to calibrate the brachytherapy sources in terms of an absorbed dose to water, the quantity of interest in the treatment, instead of an air kerma strength just as the calibration in the high energy photon and electron beam.

• Journal of Mushroom
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• v.13 no.3
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• pp.185-191
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• 2015

This research was carried out to determine the differences of physiological activites between Grifola frondosa of log cultivation(LC) and Grifola frondosa of bottle cultivation(BC). Total flavonoids content, total phenolics content, electron donating ability(EDA), nitrite-scavenging ability(NSA), SOD-like activity and inhibitory effect of Xanthine oxidase were examined. The highest value of total flavonoid content is $5.96{\pm}0.81mg/g$ in water extract from Grifola frondosa of log cultivation at $40^{\circ}C$ (LC-W40) but, one of total phenolics compound is $44.53{\pm}0.89mg/g$ in water extract from Grifola frondosa of bottle cultivation at $40^{\circ}{\cdots}$ (BC-W40). The EDA using DPPH of BC-W40 extract showed the highest value of $97.14{\pm}0.71%$. Nitrite-scavenging ability was $62.55^{\circ}{\ae}0.36%$ in extract from Grifola frondosa of BC-W40 at pH 1.2. The value was SOD-like activity showed the highest value of $18.95^{\circ}{\ae}1.39%$ in extract from LC-W40. Xanthine oxidase inhibitory activity was the highest value of $54.31{\pm}0.40%$ in extract from Grifola frondosa BC-W40, and dependent on concentrations. These results showed that a the antioxidant effects of Grifola frondosa is excellent. However, physiological activities of Grifola frondosa were not depend on caltivation method regulary, and were different according to kind of solvents, concentraitions and physialogical factors examined such as EDA, SOD-like activity and NSA.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.119-120
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• 2002

The aim is to urge the need of elaborate commissioning of 3D RTP system from the firsthand experience. A 3D RTP system requires so much data such as beam data and patient data. Most data of radiation beam are directly transferred from a 3D dose scanning system, and some other data are input by editing. In the process inputting parameters and/or data, no error should occur. For RTP system using algorithm-bas ed-on beam-modeling, careless beam-data processing could also cause the treatment error. Beam data of 3 different qualities of photon from two linear accelerators, patient data and calculated results were commissioned. For PDD, the doses by Clarkson, convolution, superposition and fast superposition methods at 10 cm for 10${\times}$10 cm field, 100 cm SSD were compared with the measured. An error in the SCD for one quality was input by the service engineer. Whole SCD defined by a physicist is SAD plus d$\sub$max/, the value was just SAD. That resulted in increase of MU by 100${\times}$((1_d$\sub$max//SAD)$^2$-1)%. For 10${\times}$10 cm open field, 1 m SSD and at 10 cm depth in uniform medium of relative electron density (RED) 1, PDDs for 4 algorithms of dose calculation, Clarkson, convolution, superposition and fast-superposition, were compared with the measured. The calculated PDD were similar to the measured. For 10${\times}$10 cm open field, 1 m SSD and at 10 cm depth with 5 cm thick inhomogeneity of RED 0.2 under 2 cm thick RED 1 medium, PDDs for 4 algorithms were compared. PDDs ranged from 72.2% to 77.0% for 4 MV X-ray and from 90.9% to 95.6% for 6 MV X-ray. PDDs were of maximum for convolution and of minimum for superposition. For 15${\times}$15 cm symmetric wedged field, wedge factor was not constant for calculation mode, even though same geometry. The reason is that their wedge factor is considering beam hardness and ray path. Their definition requires their users to change the concept of wedge factor. RTP user should elaborately review beam data and calculation algorithm in commissioning.

• Progress in Medical Physics
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• v.16 no.2
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• pp.77-81
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• 2005

To determine the appropriate method out of various available methods to measure build-up doses, the measurements and comparisons of depth doses of build-up region including the surface dose were executed using the Attix parallel-plate ionization chamber, the Markus chamber, a cylindrical ionization chamber, and a diode detector. Based on the measurements using the Attix chamber, discrepancies of the Markus chamber were within $2\%$ for the open field and increased up to $3.9\%$ in the case of photon beam containing the contaminant electrons. The measurements of an cylindrical ionization chamber and a diode detector accord with those of the Attix chamber within $1.5\%\;and\;1.0\%$ and after those detectors were completely immersed in the water phantom. The results suggest that the parallel-plate chamber is the best choice to measure depth doses in the build-up region containing the surface, however, using cylindrical ionization chamber or diode detector would be a reasonable choice if no special care is necessary for the exact surface dose.

• Progress in Medical Physics
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• v.13 no.2
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• pp.55-61
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• 2002

In this work, EPM (effective point of measurement) of parallel plate ionization chamber with three different spacing were investigated. If the plate separation is less than 2 mm one generally assumes that the effective point of measurement is just behind the front window of the parallel plate ionization chamber. For chamber with relatively large separation, such as the ones used for very accurate exposure measurements, this assumption breaks down and the EPM depends on plate separation and thickness of the front window. For parallel plate chambers, conventional theoretical analyses suggest that the EPM is the inner front wall and that it shifts towards the geometric centre of the chamber as the plate separation increases. The PP-IC (parallel plate ionization chamber) is fabricated using acrylic plate for the chamber medium and printed circuit board for electrical configuration. The various sizes of the sensitive volumes designed so far are 0.9, 1.9, and 3.1 cc. The gap between two electrodes ranges from 3, 6, and 10mm. Also the charge-to-voltage converter is designed to collect the electrons produced in the ionization chamber cavity. As the result of our experiment, the EPM shift was within 0.6 mm in photon beams and 0.4 mm to 2.5 mm in electron beams for the plate separation of 6 mm and 10 mm. EPM shifts towards the geometric center of the chamber as the plate separation increases.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.77-77
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• 2017

Titanium and its alloys offer attractive properties in a variety of applications. These are widely used for the field of biomedical implants because of its good biocompatibility and high corrosion resistance. Titanium anodizing is often used in the metal finishing of products, especially those can be used in the medical devices with dense oxide surface. Based on SAE/AMS (Society of Automotive Engineers/Aerospace Material Specification) 2488D, it has the specification for industrial titanium anodizing that have three different types of titanium anodization as following: Type I is used as a coating for elevated temperature forming; Type II is used as an anti-galling coating without additional lubrication or as a pre-treatment for improving adherence of film lubricants; Type III is used as a treatment to produce a spectrum of surface colours on titanium. In this study, we have focused on Type II anodization for the medical (dental and orthopedic) application, the anodized surface was modified with gray color under alkaline electrolyte. The surface characteristics were analyzed with Focused Ion Beam (FIB), Scanning Electron Microscopy (SEM), surface roughness, Vickers hardness, three point bending test, biocompatibility, and corrosion (potentiodynamic) test. The Ti-6Al-4V alloy was used for specimen, the anodizing procedure was conducted in alkaline solution (NaOH based, pH>13). Applied voltage was range between 20 V to 40 V until the ampere to be zero. As results, the surface characteristics of anodic oxide layer were analyzed with SEM, the dissecting layer was fabricated with FIB method prior to analyze surface. The surface roughness was measured by arithmetic mean deviation of the roughness profile (Ra). The Vickers hardness was obtained with Vickers hardness tester, indentation was repeated for 5 times on each sample, and the three point bending property was verified by yield load values. In order to determine the corrosion resistance for the corrosion rate, the potentiodynamic test was performed for each specimen. The biological safety assessment was analyzed by cytotoxic and pyrogen test. Through FIB feature of anodic surfaces, the thickness of oxide layer was 1.1 um. The surface roughness, Vickers hardness, bending yield, and corrosion resistance of the anodized specimen were shown higher value than those of non-treated specimen. Also we could verify that there was no significant issues from cytotoxicity and pyrogen test.

• Applied Biological Chemistry
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• v.49 no.2
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• pp.129-134
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• 2006

Biological activities and application of Isodon japonicus H. were investigated. In the physiological activities, the electron donating ability (EDA) was 66.3% in 100 ppm and SOD-like activity was as high as 85.0% in 1,000 ppm with gradual increase. As for the inhibitory effect of xanthine oxidase, it was 70.0% in 1,000 ppm and as low as 40.0% in 500 ppm; also, as for the inhibitory effect of tyrosinase, it was as low as 20.5% below 1,000 ppm. The tyrosinase inhibition effect related to skin whitening function showed 30.0% at 1,000 ppm level or below, indicating a relatively low effect. As for the result of measuring the lipid oxidation, all the concentrations of medical ion treatments showed anti-acidification ability; also, as for the metal ion blocking effects against the lipid oxidation promoting factors $(Fe^{2+}\;and\;Cu^{2+})$, $Fe^{2+}$ was better than $Cu^{2+}$ and all concentrations of medical ion treatments was 60.0% in 100 ppm. Also, the clear zone against various bacteria at 0.5 and 1.0 mg/disc was clearly shown. When it was applied into a normal skin-softener, it was safe, showing its potential as a natural material of cosmetics.

• Progress in Medical Physics
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• v.15 no.4
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• pp.215-219
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• 2004

Due to their excellence for the high-energy therapy range of photon beams, researchers show increasing interest in applying MOSFET dosimeters to low- and medium-energy applications. In this energy range, however, MOSFET dosimeter is complicated by the fact that the interaction probability of photons shows significant dependence on the atomic number, Z, due to photoelectric effect. The objective of this study is to develop a very detailed 3-dimensional Monte Carlo simulation model of a MOSFET dosimeter for radiological characterizations and calibrations. The sensitive volume of the High-Sensitivity MOSFET dosimeter is very thin (1 ${\mu}{\textrm}{m}$) and the standard MCNP tallies do not accurately determine absorbed dose to the sensitive volume. Therefore, we need to score the energy deposition directly from electrons. The developed model was then used to study various radiological characteristics of the MOSFET dosimeter. the energy dependence was quantified for the energy range 15 keV to 6 MeV; finding maximum dependence of 6.6 at about 40 keV. A commercial computer code, Sabrina, was used to read the particle track information from an MCNP simulation and count the tracks of simulated electrons. The MOSFET dosimeter estimated the calibration factor by 1.16 when the dosimeter was at 15 cm depth in tissue phantom for 662 keV incident photons. Our results showed that the MOSFET dosimeter estimated by 1.11 for 1.25 MeV photons for the same condition.

• Tuberculosis and Respiratory Diseases
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• v.38 no.2
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• pp.143-154
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• 1991

Pneumconiosis is a sort of pulmonary fibrosis consequent to the inhalation of the respirable dusts. Thus, the pathogenesis of silicosis have concentrated largely on the early response of alveolar macrophage and the later fibroblastic stimulation. But the role of the other cells and continuing cell injury in the pathogenesis has not been fully studied. And the chemical factors such as prostaglandin, fibroblast stimulating factor and inhibiting factor and chemotaxin are also participated in the mechanism of pulmonary fibrosis in silicosis. In order to clarify the role of alveolar cells and prostaglandin, we investigated the changes of the cellularities in bronchoalveolar lavage fluid and tissue pathology in the experimental silicosis with the time sequence. The experimental animals were divided into 3 groups; control group received only intratracheal injection of 0.5 ml saline, silica group received the intratracheal instillation of 40 mg silica with the same amount saline, and aspirin group received 450 mg/kg of aspirin after silica instillation. The results were as follows: 1) The total cells of bronchoalveolar lavage fluid in the silica group markedly increased in comparison with the control group, but there was no significant difference between the silica and aspirin groups. 2) The percentages of alveolar macrophages to the total number of cells in the silica group tended to be lower than those in the control group and also lower than those in the aspirin group at the 1st week after silica instillation. 3) The percentages of neutrophils to the total number of cells in the silica group were significantly higher than those in the control group during the entire period and also higher than those in the aspirin group at the 3rd day after silica instillation. 4) In the silica group, the percentages of lymphocytes to the total number of cells were increased 143 progressively with the time course and those were significantly higher than those in the control group from the 3rd week after silica administration. There were marked differences of lymphocyte percentages between the silica and aspirin groups at the 1st week after silica instillation. 5) The inflammatory change was observed in the rat lung at the 1st day after silica instillation. Also the silicotic nodule appeared in the silica group at the 1st week but we could not find out that nodule in the aspirin group at that time. The fibrotic changes in the rat lung tended to be increased progressively with the time course, therefore, the diffuse fibrotic pattern appeared in the whole field at the 20th week after silica instillation. 6) By the electron microscopy, there were gradual increases of phagosomes and vacuoles in the alveolar macrophage in the silica group as compared with the control group. These results suggest that the neutrophils and the lymphocytes have also participated in the pulmonary fibrosis even though the alveolar macrophage has a major role, and prostaglandin mediate the inflammation and pulmanary fibrosis in the experimental silicosis.