• Journal of the Korean Society of Tobacco Science
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• v.12 no.1
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• pp.29-38
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• 1990

Until relatively recently plant scientists have made little use of immunological techniques. Now, however, more and more researchers are discovering the powder of these techniques for the screening of immunomodulators and for the detection, quantitative determination and localization of compounds in plant materials. Especially, the recent developments in the fields of plant biotechnology and plant genetic engineering make it even more important for forkers in the plant sciences to become acquainted with the more sophisticated methods. The possible methods include onestep purification of antigens, visualization in situ by immunocytochemis try and on polyacrylam ids gel s by ni trocellulose Western blotting and quantification by various immunoassay. Among them, in this reviews, the quantitative determination methods are to be reviewed. There are several kinds of methods for the quantitative determination of plant constituents such as colorimetry, TLC, GLC, DCC, UV derivatization, densitometry and HPLC. When the complexity of plant constituents is considered. densitometry and HPLC have many advantages in sensitivity and separation ability. After a 11 some advarltages of two methods meritiorled above, all of these methods have many disadvantages and inconveniences. Previous purification for the application of all these methods make them less sensitive and more tedious. Immunoassay can solve these problems in part. But immunoassay also has some limitations. Specificity of immunoassay, contrary, can be considered to be disadvantages. Including this the advantages and disadvantages of immunoassay are to be discussed.

• BMB Reports
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• v.35 no.4
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• pp.364-370
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• 2002

The effect of sodium n-dodecyl sulphate (SDS) on hemoglobin autoxidation was studied in the presence of a 100mM phosphate buffer (pH 7.0) by different methods. These included spectorphotometry, fluorescence technique, cyclic voltametry, differential scanning calorimetry, and densitometry. Spectroscopic studies showed that SDS concentrations up to 1 mM increased deoxy-, decreases oxy-, and had no significant effect on the met- conformation of hemoglobin. Therefore, a SDS concentration up to 1 mM increased the deoxy form of hemoglobin as the folded, compact state and decreases the oxy conformation. The turbidity measurements and differential scanning calorimetry techniques indicated a more stable conformation for hemoglobin in the presence of SDS up to 1mM. Electrochemical studies also confirmed a more difficult oxidation under these conditions. The induction of the deoxy form in the presence of SDS was confirmed by densitometry techniques. The compact structure of deoxyhemoglobin blocks the formation of met-conformation in low SDS concentrations.

• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.307-316
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• 1990

Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The densitometry and bone scintigraphy are valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of Cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absorptiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before the presentation of the osteoradionecrosis can be diagnosed early with the dual photon absorptionmetry and bone scintigraphy.

• Imaging Science in Dentistry
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• v.52 no.4
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• pp.375-382
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• 2022

Purpose: The aim of this study was to analyze the relationships between bone density measurements obtained using cone-beam computed tomography (CBCT) and morphometric parameters of bone determined by histomorphometric analysis. Materials and Methods: In this in vivo study, 30 samples from the maxillary bones of 7 sheep were acquired using a trephine. The bone samples were returned to their original sites, and the sheep heads were imaged using CBCT. On the CBCT images, gray values were calculated. In the histomorphometric analysis, the total bone volume, the trabecular bone volume (referred to simply as bone volume), and the trabecular thickness were assessed. Results: Statistical testing showed significant correlations between CBCT gray values and total bone volume (r =0.537, P =0.002), bone volume (r =0.672, P<0.001), and trabecular thickness (r =0.692, P<0.001), as determined via the histomorphometric analysis. Conclusion: The results indicate a significant and acceptable association between CBCT gray values and bone volume, suggesting that CBCT may be used in bone densitometry.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.11-22
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• 2023

Bone densitometry is a disease in which bones are easily broken due to metabolic bone disease, and DXA is used as a clinical standard test. Although DXA is a good method with good accuracy and reproducibility, it is frequently subject to test errors in testing and result analysis and analysis. Therefore, it is important to recognize the error issues that radiologists should basically be aware of when performing bone density tests, prevent erroneous diagnoses and treatments resulting from the results, and reduce the unnecessary costs associated with them. aim. The inspection must be carried out if the quality control of the equipment is basically continuously performed well before the inspection. Before starting the examination, the patient's age, sex, race, weight, pregnancy status, and any foreign objects that can be removed should be checked, and the examination should be performed in the correct posture. In addition, it is important to analyze results consistently. Radiologists, who play the most important role in ensuring accurate examinations, need to be aware of the potential for errors in advance and develop the ability to deal with the potential for errors in each examination. For that reason, regular education is considered essential.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.07a
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Korean Journal of Pharmacognosy
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• v.7 no.3
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• pp.191-193
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• 1976

It has been known that ginseng extract contains several polyacetylene components. But we found only two polyacetylene components in the freshly prepared ginseng extract. Long-term preservation of ginseng or ginseng extract produced many artifact polyacetylenes. The ratio of artifact/genuine polyacetylene was determined by TLC-densitometry on long-term preserved ginseng samples. The results indicated that the ratio was increased proportionally with the span of preservation.

• YAKHAK HOEJI
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• v.22 no.4
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• pp.242-249
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• 1978

We have compared the panaxadiol and panaxatriol contents of white ginsengs from different countries and red ginseng, by using gas and high-pressure liquid chromatographies. Oleanolic acid contents in various ginseng species were compared by gas liquid chromatography and densitometry. Korean ginseng was found to contain greater amount of panaxadiol and panaxatriol than those of any other countries. The ginsengs from other countries, especially Chikusetzu ginseng, were found to contain far greater amount of oleanolic acid than Korean ginseng.

• Korean Journal of Medicinal Crop Science
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• v.13 no.3
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• pp.101-104
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• 2005

To explore the Korea native plants to substitute for St. John's wort, which produce hypericin that use commercially for the treatment of mild to moderate depression, hypericin contents of Hypericum erectum and H. ascyron collected in two mountain of Korea were examined. From TLC and TLC-densitometer analysis of hypericin contents and biosynthetic pattern, hypericin was detected in flower and leaf of H. erectum, but not in all organs of H. ascyron. The hypericin content of H. erectum grown 200 m high hill in Mt. Byoung-pung was higher than that of Mt. Ji-ri 500 m and 1300 m high hill. When the seasonal variation of hypericin contents in H. erectum leaf collected from two regions was investigated, leaf collected from both regions on July was higher than other seasons.

• The Korean Journal of Zoology
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• v.28 no.4
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• pp.227-236
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• 1985

In an attempt to make a scrutiny into a mechanism for the formation of quaternary structure of LDH isozymes, male mice were intraperitoneally exposed to a wide range of tetrodotoxin concentration and the changes in relative percentage of the five isozymes were monitored by electrophoresis and subsequent densitometry. The observations that a conspicuous increase of the $H_4$ isozyme was demonstrated in nearly all brain tissues, that the $M_4$ isozyme of skeletal muscle tissue was slightly increased while the $M_3H$ and $M_2H_2$ isozymes were decreased, that the M/H ratio was strikingly reduced in heart tissue and that assembly of $H_4$ isozyme was revealed in liver tissue although its rate was extremely low suggest that new intracellular ionic environment established by compulsory change in Donnan equilibrium could alter the LDH isozyme distribution. The reduction of assembly of $M_3H$ isozyme found in mouse tissues exposed to tetrodotoxin also seems to suggest that the subunit combination of 3M+H is very unfavorable in an intracellular environment deviated from its accustomed one. It was reaffirmed that there might occur TTX-insensitive sodium channels in plasma membrane.