• Progress in Medical Physics
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• v.10 no.1
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• pp.17-22
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• 1999

INJ-I, INJ-E, PFN, BMI, and PRF were selected among the various factors which constitute a digital linear accelerator to find effects on the dose distribution by changing current and voltage within the permitted scale which Mevatron automatically maintained. We measured the absorbed dose using an ion chamber, analyzed the waveform of beam output using an oscilloscope, and measured symmetry and flatness using a dosimetry system. An RFA plus (Scanditronix, Sweden) device was used as a dosimetry system. Then an 0.6cc ion chamber (PR06C, USA), an electrometer (Capintec192, USA), and an oscilloscope (Tektronix, USA) were employed to measure the changes on the dose distribution characteristics by changing the beam-tuning parameters. When the currents and the voltages of INJ-I, INJ-E, PFN, BMI, and PRF were modified, we were able to see the notable change on the dose rate by examining the change of the output pulse using the oscilloscope and by measuring them using the ion chamber. However, the results of energy and flatness graph from RF A plus were almost identical. The factors had fine differences: INJ-I, INJ-E, PFN, BMI, and PRF had 0.01∼0.02% differences in D10/D20, 0.1∼0.2 % differences in symmetry, and 0.1∼0.4% differences in flatness. Since Mevatron controlled itself automatically to keep the reference value of the factor, it was not able to see large differences in the dose distribution. There were fine differences on the dose rate distribution when the voltage and the currents of the digitized factors were modified Nonetheless, a basic operational management information was achieved.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.299-306
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• 2009

Purpose : To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Materials and Methods : Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation ($0.625\;mm{\times}64\;ea$), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of $40{\sim}80%$ of R-R interval and 120mA(80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. Results : The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with that of conventional coronary CTA. And heart dose was 33.8 mGy, this represents 67.4% reduction. In the sequential scan technique under prospective ECG gating with low kVp the mean effective dose was 3.0 mSv, this represents an 83.2% reduction compared with that of conventional coronary CTA. And heart dose was 17.7 mGy, this represents an 82.9% reduction. Conclusion : In coronary CTA at retrospectively ECG gated helical scan, cardiac dose modulation technique using low kVp reduced dose to 50% above compared with the conventional helical scan. And the prospectively ECG gated sequential scan offers substantially reduced dose compared with the traditional retrospectively ECG gated helical scan.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.4
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• pp.165-178
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• 2018

Objectives: To determine the current status of the treatment of breast cancer patients by Korean Medicine doctors (KMDs) and to examine the need for clinical practice guidelines (CPGs) for the supportive care of these patients. Methods: This cross-sectional study used a self-administered questionnaire. Participants were asked about their experience in treating breast cancer patients; the number of breast cancer patients they currently treat; the main complaints expressed by, diagnoses of, and treatments used for such patients; and their opinions about Korean Medicine (KM) as the basis for providing supportive care for breast cancer. Results: The data for this study were collected from 322 respondents. 84 of whom reported having ever treated patients with breast cancer. Most breast cancer patients who visited the KM clinic were classified as stage I or II, and their major complaints were fatigue, general weakness and musculoskeletal pain. The major diagnostic strategies were syndrome differentiation and pulse diagnosis. The major treatments administered were herbal medicine, acupuncture, and moxibustion. KMDs cited a need for medical information, such as CPGs, as their most important concern with regard to the treatment of breast cancer patients. Conclusions: This survey determined the prevalence of the use of KM for Korean breast cancer patients. Our results underscore the need for clinical practice guidelines for using of KM as the basis of supportive care for breast cancer and for informing clinicians and patients about this approach.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.12
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• pp.844-861
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• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

• The Journal of Internal Korean Medicine
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• v.18 no.2
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• pp.268-295
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• 1997

Sweating is natural phenomenon necessary for the regulation of an individual's body-temperature. The secretion of sweat is mediated by a portion of our vegetative nervous system(the sympathetic nervous system). In some people, this system is working at a very high activity level, far higher than needed to keep a constant temperature. This condition is referred to as hyperhidrosis. Especially excessive sweating of the hands and the feet is palmoplantar hyperhidrosis or volar hyperhidrosis. This is by far the most distressing condition. It was founded that the first important cause of this was emotional factor. The hands are much more exposed in social and prefessional activities than any other part of our body. Many individuals with palmoplantar hyperhidrosis are limited in their choice of proffession, because unable to manipulate materials sensitive to humidity or reluctant to shake hands; some patients arrive to the point to avoid social contact. The occidental medical treatments for palmoplantar hyperhidrosis include application of topical agents(chemical antiperspirants such as aluminum chloride), iontophoresis(treatment with electrical current), or surgery(thoracic sympathectomy). It was reported that the most effective treatment was thoracic sympathectomy. So this study was started to find the easy and effective oriental medical treatments against the occidental medical treatments through the oriental medical literature. The occidental medical idea for palmoplantar hyperhidrosis is only limited in neurologic system, so surgery is the best treatment. But the oriental medical idea for palmoplantar hyperhidrosis is much wider, so the oriental medical causes and treatments for this are able to be veriety. And the oriental medical teatment is freely in treating the patients of palmoplantar hyperhidrosis, because entire idea including pulse, facial color, mental condition, constitution and other symptom exists in the oriental medicine. The results of a bibliographic study of causes and treatments for palmoplantar are as follows; 1. The main causes of pa1moplantar hyperhidrosis are heat in the stomach, damp-heat in the spleen and the stomach, insufficiency of the spleen-qi and the stomach-qi, deficiency of the spleen-yin and the stomach-yin, and the others are the stomach-cold syndrome, stasis of blood and dyspepsia in the stomach, disorder of the liver-qi, deficiency of the heart-yin and the kidney-yin, deficiency of the heart-yang and the kidney-yang, stagnated heat in the liver and the spleen, the lung channel-heat etc. 2. The main methods of medical treatments for palmoplantar hyperhidrosis are clearing out the stomach-heat, eliminating dampness and heat in the spleen and the stomach, invigorating the spleen-qi and the stomach-qi, reinforcing the spleen-yin and the stomach-yin, warming the stomach, relaxing the liver and alleviating of mental depression and tonifying the heart and the kidney etc. 3. The main prescriptions of palmoplantar hyperhidrosis are Taesihotang, Palmultang-kakam, Samyeongbaechusan, Chongbisan, Sasammaekmundongtang, the others are Leejungtang, Hwangkikonjungtang, Seungkitang, Boyumtang, Baekhotang, Chongsimyonjayum, Moyrosan, etc. 4. Local medicine for external use are liquid after boiling alum in water for about 1 or 2 hours, liquid after boiling alum and pueraria root in water and liquid after boiling stragalus root, pueraria root, ledebouriella root and schizonepeta in water, etc. 5. The methods of acupuncture therapy include invigorating Bokyru, Yumkuk and purgating Hapkouk, or invigorating Bokyru, Kihae and purgating Hapkouk, or steadying Hapkouk, Nokung.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.258-263
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• 2023

In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.