• Applied Microscopy
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• v.24 no.1
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• pp.28-40
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• 1994

Xerostomia and xerophthalmia are delicate or serous side effects, occuring when the radiotherapy is administered to the head and neck cancer patient. It is known that the cause of the above side effect is radiosensitivity of serous cells. In this study, the ultrastructural features of the parotid glands of the X-irradiated rats were observed. Sprague-Dawley rats weighing 200-250g each were anesthetized with sodium thiopental, and placed on the Mitsubishi linear accelerator. Only the head and neck areas of animals were exposured at the distance of 80cm, within the area of $30X30cm$, in the depth of 1cm, with the speed of 200R/min. Total doses applied were 3,000R or 6,000R depending on the experimental groups. Animals were sacrificed on the 6th hour, 2nd day and 6th day after the irradiation. Parotid glands were fixed in the 2.5% glutaraldehyde-1.5% paraformaldehyde solution, and followed by refixation in the 1% osmium tetroxide solution. Dehydrated blocks were embedded in araldite mixture, and ultrathin sections were cut. Sections were contrasted with the solution of uranyl acetate and lead citrate, and observed with JEM 100 CX-II electron microscope. The results were as follows: 1. Normal parotid acinar cells are two types; the light and the dark acinar cells. The light acinar cell contains dense secretory granules, whereas dark acinar cells contains granules of medium density with some darker spots within them, or other cells contain granules of medium density with darker rims. 2. Six hours after the irradiation, many acinar cells were degenerated showing variable stages of cytolytic bodies, light bodies, or dense degenerations. Within the acinar cell, Golgi apparatus and granular endoplasmic reticula were most severely altered elements. Granules showed more contrasting densities and irregularities. 3. Two days after the irradiation, some cytolytic bodies, and focal lucent degeneration of cytoplasm, and fine granular alteration of cytoplasmic matrix were pronounced. But other elements including secretory granules are rather looked unlatered. 4. Six days after the irradiation, most severe alterations were seen. Many intracellular canaliculi (or secretion figures), quanta of cytoplasm containing secretion antecedants, severely irregular luminal border, and again contrasting density of secretory granules showing tigroid spots or dense rims were noted. And myoepithelial degenerations were observed not uncommonly. 5. Irregular densities of secretory granules were interpreted as abnormal components of protein or carbohydrate portion are synthesized or abnormally metabolized under severe X-irradiation. 6. Myoepithelial degeneration and related alteration of nerve endings, etc., were suggested as the other causes of xerostomia following X-irradiation. 7. It is requested that radiation doses should be arranged, considering in mind not only the sensitivity of acinar cells but also the myoepithelial and neural functions.

• Journal of radiological science and technology
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• v.34 no.2
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• pp.149-156
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• 2011

This study is to identify perceptions and response degrees of anxiety for each factor, targeting patients for CT test and analyze the relations between factors. It is to provide scientific fundamental data to reduce anxiety by improving awareness of patients about CT test by analyzing relations between variables. The subjects of this study were surveyed in self-writing type, targeting 263 patients for CT test in the department of radiology at three University hospitals from July to September, 2010. This survey was executed once by a structured self-administered survey type. The targeting patients for CT test of anxiety will investigate for affect. Anxiety by each CT test variables depending on CT test-related features showed independent variable is Expense Responsibility, Economic burden, Sufficient explain, Explain agent, Endoscope, Biopsy, Pre treatment, Previous experience, CT side effect experience, Side effect of contrast medium and dependent variable is physical, Hospital staff, Hospital environment, Socioeconomic These used statistics program SPSS (ver. 13.0). Summarizing the above results of this study, awareness of anxiety and response to it in each variable under CT test appeared significant differences in economic burdens, state anxiety, pre-treatment anxiety, exposure anxiety to radiation, and anxiety of side effect. Therefore, pre-treatment before test and pre-training programs on chemical poison of contrast medium and side effect seem to be able to release patients' anxiety level for CT test. Ways to meditate these anxiety variables and reduce degree of anxiety are needed to be researched more and updated. In addition, impact of patients' economic burdens on CT test anxiety is required to be recognized and solved in society level.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.933-939
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• 2019

The purpose of this study is to provide basic clinical data by evaluating images, measuring absorbed dose and effective dose by using high resolution CT and low dose CT by using anthropomorphic chest phantom and glass dosimeter. Tissue dose was measured by inserting a glass dosimeter into the anthropomorphic chest phantom. A 64-slice CT system (SOMATOM Sensation 64, Siemens AG, Forchheim, Germany) and CARE Dose 4D were used, and the parameters of the high resolution CT were 120 kVp, Eff. Scan parameters of mAs 104, scan time 7.93 s, slice 1.0 mm (Acq. 64 × 0.6 mm), convolution kernel (B60f sharp) were used, and low dose CT was 120 kVp, Eff. mAs 15, scan time 7.41 s, slice 3.0 mm (Acq. 64 × 0.6 mm), scan of convolution kernel B50f medium sharp. CTDIvol was measured at 8.01 mGy for high resolution CT and 1.18 mGy for low dose CT. Low dose CT scans showed 85.49% less absorbed dose than high resolution CT scans.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.298-308
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• 1988

This study was carried out to get infirmation for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in Japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effentive ripening.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.309-314
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• 1988

This study was carried out to get information for the breeding varieties and developing the cultural methods with representative 32 cultivars which were diffused from 1900 to 1982 and two cultural methods which were old one i.e., low dressing and late planting and modern one i.e., medium dressing and early planting. Duration of transplanting between cultural practices were 15 days but the duration of heading date were 5 days. Panicle projecting duration was 5-10 days in all cultivars, especially, it is 5 days in early maturing varieties, 6-7 days in medium maturing varieties and 7-10 days in late maturing varieties. Periods from transplanting date to effective ripening date were 99.8 days in low dressing and late planting method, 106.2 days in modern one but the periods from heading date to effective ripening date were 31.4 days in low dressing and late planting method, 30.2 days in modern one. Ripening speed was very active from 5 to 10 days after heading and the daily increase of 1000 grain weight was from 847.8mg to 1130mg in that time and it slightly increased from 5 to 35 days after heading in japonica varieties but increased after heading and suddenly decreased at 30 days after heading in Indica/Japonica varieties. Meteorological factors (temperature and amount of solar radiation) were positively correlated with the ripening speed but negatively correlated with the period of physiological and effective ripening.

• Applied Microscopy
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• v.22 no.2
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• pp.1-14
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• 1992

This experiment was performed to study the morphological responses of the parafollicular cells of rat following X-ray irradiation. Male rats were divided into normal and experimental groups. The head and neck region of the rat, under sodium thiopental anesthesia, was exposed to 3,000 rads or 6,000 rads of radiation in a single dose, respectively. The source was a Mitsubishi Linear Accelerator ML-4MV. The target to skin distance was 80 cm, and the dose rate was 200 rads/min. The rate of experimental groups were sacrificed on the 6th hour, 2nd and 6th day after X-ray irradiation. Pieces of the tissue taken from the thyroid gland were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde (0.1M Millonig's phosphate buffer, pH 7.3), and in 1% osmium tetroxide (0.1M Millonig's phosphate buffer, pH 7.3), and embedded in araldite mixture. The ultrathin sections stained with uranyl acetate and lead citrate were observed with JEM 100 CX-II electron microscope. The results were as follow; 1. Two types of the parafollicular cells, according to their electron densities, were found, i. e., light cells and dark cells. 2. Three types of the parafollicular cells, according to their sizes of secretory granules were found, i.e., small granule cells ($85nm{\pm}20.1;64{\sim}102nm$), medium granule cells ($120nm{\pm}26.5;77{\sim}179nm$), and large granule cells ($165nm{\pm}25.7;128{\sim}189nm$). 3. The differential ultrastructural changes of the cells according to their cell types, i.e., dark and light cell, or small, medium and large granule cells, were hardly observed in the time and dose range covered by this study. 4. The morphological changes of the parafollicular cells were not pronounced after exposure to 3,000 rads of X-ray. 5. Swollen cisternae of the granular endoplasmic reticulum and partial cytolysis were observed after exposure to 6,000 rads of X-ray. 6. Above results suggest that the parafollicular cells showed the alterations of mitochondrial and granular endoplasmic reticular swelling, and partial cytolysis, but only in doses of 6,000 rads.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.589-595
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• 2023

If complete coronary artery occlusion occurs due to severer coronary spasm, malignant arrhythmias can lead to death. Therefore, early screening for coronary artery spasm angina is essential. Among the test methods, the drug injection test through coronary angiography is generally performed. Therefore, the purpose of this study was to evaluate the advantages of ergonovine drug test for vasospasitc angina examination during coronary angiography, such as the relationship between the procedure time, contrast medium usage, and radiation exposure effects of coronary angiography. Follow-up data of 142 patients who underwent coronary angiography and variant angina examination from september 2021 to february 2023 were used. As a result of analyzing contrast usage dose and dose area product and air kerma dose and number of imaging series and procedure time, variant angina examination was statistically significantly higher than coronary angiography. (p<0.001) In conclusion, variant angina examination other than coronary artery angiography are radiologically negative. Therefore, we think it is better to avoid excessive inspection. Nevertheless, in the case of the provocation test, the longer the examination time, the higher the fluoroscopy time and the amount of contrast medium used, so it is better to conduct the test as quickly as possible or shorten it.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.195-200
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• 2012

We show how the rotation emission from isolated interstellar Polycyclic Aromatic Hydrocarbons (PAHs) can explain the so-called anomalous microwave emission (AME). AME has been discovered in the last decade as microwave interstellar emission (10 to 70 GHz) that is in excess compared to the classical emission processes: thermal dust, free-free and synchrotron. The PAHs are the interstellar planar nano-carbons responsible for the near infrared emission bands in the 3 to 15 micron range. Theoretical studies show that under the physical conditions of the interstellar medium (radiation and density) the PAHs adopt supra-thermal rotation velocities, and consequently they are responsible for emission in the microwave range. The first results from the PLANCK mission unexpectedly showed that the AME is not only emitted by specific galactic interstellar clouds, but it is present throughout the galactic plane, and is particularly strong in the cold molecular gas. The comparison of theory and observations shows that the measured emission is fully consistent with rotation emission from interstellar PAHs. We draw the main lines of our PLANCK-AKARI collaborative program which intends to progress on this question by direct comparison of the near infrared (AKARI) and microwave (PLANCK) emissions of the galactic plane.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.353-356
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• 2012

We present new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (${\sim}0.44{\mu}m$) and red (${\sim}0.64{\mu}m$) bands. Accurate starlight subtraction was achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with the thermal $100{\mu}m$ brightness, whilst the other shows a constant level in the lowest $100{\mu}m$ brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has an extragalactic origin (i.e., the COB). The derived COB brightness is ($(1.8{\pm}0.9){\times}10^{-9}$ and $(1.2{\pm}0.9){\times}10^{-9}\;erg\;s^{-1}\;cm^{-2}\;sr^{-1}\;{\AA}^{-1}$ in the blue and red spectral regions, respectively, or $7.9{\pm}4.0$ and $7.7{\pm}5.8\;nW\;m^{-2}\;sr^{-1}$. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions from other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)-scattered starlight by the interstellar dust. We derive the mean DGL-to-$100{\mu}m$ brightness ratios of $2.1{\times}10^{-3}$ and $4.6{\times}10^{-3}$ at the two bands, which are roughly consistent with previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.27-33
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• 2016

The aim of numerical study is the investigation of the solid and fluid temperatures in a reformer tube and chemical reaction characteristics of different steam-carbon ratio. We considered conjugate heat transfer contain radiation, convection and conductive heat transfers. This is because steam reforming reaction of hydrocarbon occurred high temperature conditions up to 800 K- 1000 K by using commercial computational fluid dynamics (CFD) code (Fluent ver. 13.0). For numerical simulation, the Reynolds-Averaged Navier-Stokes, momentum and energy equation were employed. In addition, inside of reformer tube is assumed as the porous medium to consider the Nichrome-based catalyst. To analysis characteristics of tube temperature in chemical reaction, we changed steam-methane ratio(SCR) from 1 to 6. As increased SCR, the higher tube temperature and methane conversion were observed. It was obtained that the highest hydrogen production held in SCR of 5.