• Advances in nano research
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• v.13 no.5
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• pp.417-426
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• 2022

Bisphenol A (BPA) is one of the chemicals used in monomer epoxy resins and polycarbonate plastics. The surface-enhanced Raman spectroscopy (SERS) method is precise for identifying biological materials and chemicals at considerably low concentrations. In the present article, the substrates coated with gold nanoparticles have been studied to identify BPA and control the diseases caused by this chemical. Gold nanoparticles were made by a simple chemical method and by applying gold salt and trisodium citrate dihydrate reductant and were coated on glass substrates by a spin-coat approach. Finally, using these SERS substrates as plasmonic sensors and Raman spectroscopy, the Raman signal enhancement of molecular vibrations of BPA was investigated. Then, the molecular vibrations of BPA in some consumer goods were identified by applying SERS substrates as plasmonic sensors and Raman spectroscopy. The fabricated gold nanoparticles are spherical and quasi-spherical nanoparticles that confirm the formation of gold nanoparticles by observing the plasmon resonance peak at 517 nm. Active SERS substrates have been coated with nanoparticles, which improve the Raman signal. The enhancement of the Raman signal is due to the resonance of the surface plasmons of the nanoparticles. Active SERS substrates, gold nanoparticles deposited on a glass substrate, were fabricated for the detection of BPA; a detection limit of 10-9 M and a relative standard deviation (RSD) equal to 4.17% were obtained for ten repeated measurements in the concentration of 10-9 M. Hence, the Raman results indicate that the active SERS substrates, gold nanoparticles for the detection of BPA along with the developed methods, show promising results for SERS-based studies and can lead to the development of microsensors. In Raman spectroscopy, SERS active substrate coated with gold nanoparticles are of interest, which is larger than gold particles due to the resonance of the surface plasmons of gold nanoparticles and the scattering of light from gold particles since the Raman signal amplifies the molecular vibrations of BPA. By decreasing the concentration of BPA deposited on the active SERS substrates, the Raman signal is also weakened due to the reduction of molecular vibrations. By increasing the surface roughness of the active SERS substrates, the Raman signal can be enhanced due to increased light scattering from rough centers, which are the same as the larger particles created throughout the deposition by the spin-coat method, and as a result, they enhance the signal by increasing the scattering of light. Then, the molecular vibrations of BPA were identified in some consumer goods by SERS substrates as plasmonic sensors and Raman spectroscopy.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.1
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• pp.38-48
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• 2011

Purpose: Dentists suffer back, neck and shoulder pain during their careers due to bad operating posture. If dentists have a good operating posture ergonomically, there would be less pain and discomfort in the shoulder and back. Therefore, dentists should learn the Home position which enables dentists to approach a stable posture ergonomically. This study was to compare tooth preparation in the Home position and the Random position, and evaluate the clinical efficacy of the Home position. Materials and methods: Tooth preparation for fixed partial denture was performed on the maxillary left 2nd premolar and maxillary left 2nd molar at the two different operating positions were compared. The amount of occlusal reduction, marginal width, subgingival margin depth, and convergence angle were measured. A T-test was performed separately to compare the results of the Random position and the Home position. Results: 1. The amounts of average thickness of occlusal reduction on fossa were deficient to the ordered ones in the Random position and the Home position (P > .05). 2. The average subgingival margin depth of prepared margin on maxillary left 2nd premolar, maxillary left 2nd molar were excessive in the Random position than in the Home position. On the maxillary left 2nd premolar, there was no statistical difference in the Random position and the Home position except Distal midline, DL line angle, Lingual midline, ML line angle (P< .05). On the maxillary left 2nd molar, there was no statistical difference in the Random position and the Home position (P < .05). 3. Average convergence angle in the Random position and the Home position were excessive compared to the ordered angle. There was no statistical difference in the Random position and the Home position (P > .05). 4. Analysis of pearson correlation : In the Random position, the amounts of average thickness of occlusal reduction, the average subgingival margin depth of prepared margin, convergence angle were significantly associated with each other (P < .05). But in the Home position, they were not significantly associated with each other (P < .05). 5. The time needed for preparation in the Home position was faster or equal than that of the Random position as time went on. Conclusion: In conclusion, there were no significant differences between Home position and Random position in measures of occlusal reduction, marginal width, marginal depth, convergence angle. However, preparation time and incidence of damaging adjacent teeth were less in Home position than in Random position. Therefore, if trained properly, Home position which is more ergonomically stable can be adopted for clinical use.

• Journal of the Korean Society of Radiology
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• v.7 no.2
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• pp.121-129
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• 2013

In this study measured patient exposure dose for purpose exposure area and peripheral critical organs by using optically stimulated luminescence dosimeters (OSLDs) from computed tomography (CT), based on the measurement results, we predicted the radiobiological effects, and would like to advised ways of reduction strategies. In order to experiment, OSLDs received calibration factor were attached at left and right lens, thyroid, field center, and sexual gland in human body standard phantom that is recommended in ICRP, and we simulated exposure dose of patients in same condition that equal exposure condition according to examination area. Average calibration factor of OSLDs were $1.0058{\pm}0.0074$. In case of left and right lens, equivalent dose was measure in 50.49 mGy in skull examination, 0.24 mGy in chest, under standard value in abdomen, lumbar spine and pelvis. In case of thyroid, equivalent dose was measured in 10.89 mGy in skull examination, 7.75 mGy in chest, 0.06 mGy in abdomen, under standard value in lumber spine and pelvis. In case of sexual gland, equivalent dose was measured in 21.98 mGy, 2.37 mGy in lumber spine, 6.29 mGy in abdomen, under standard value in skull examination. Reduction strategies about diagnosis reference level (DRL) in CT examination needed fair interpretation and institutional support recommending international organization. So, we met validity for minimize exposure of patients, systematize influence about exposure dose of patients and minimize unnecessary exposure of tissue.

• Journal of Life Science
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• v.21 no.2
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• pp.322-327
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• 2011

The effects of green tea consumption and/or exercise for 12weeks on body weight and select biochemical markers in plasma were evaluated in obese adolescents with a fat ratio of greater than 25%. The subjects were randomly divided into a control group (n=9), green tea consumption group (n=9), exercise group (n=9) and green tea consumption with exercise group (n=9). Subjects in both green tea consumption group and green tea consumption with exercise group were given more than five cups of green tea extract in hot water ($90^{\circ}C$) daily, equivalent to 1.5-1.7 g dry green tea, for 12 weeks. Subjects in both the exercise group and green tea consumption with exercise group participated in a training program (HRmax 60-70%, 60 min/day) for 12 weeks. Control subjects were only given water equal to the quantity of green tea being given to the subjects of green tea consumption. No significant changes body weights were seen in any of these treatments, but the waist to hip ratio was reduced with treatments of both green tea and exercise. The control group showed no significant changes in TNF-$\alpha$, IL-6 and leptin levels. Green tea consumption reduced leptin (p<0.05), TNF-$\alpha$, and leptin levels. Exercise lowered TNF-$\alpha$ (p<0.05), IL-6 (p<0.01), and leptin (p<0.05) concentrations. Meanwhile, a combination of green tea consumption and exercise lowered TNF-$\alpha$, IL-6 (p<0.05) and leptin (p<0.05) levels. These results indicate that green tea consumption and exercise both had a positive effect on the reduction of inflammatory cytokines, TNF-$\alpha$, IL-6 and leptin, in obese adolescents, but no synergistic effect on the reduction of these cytokines.

• Journal of Korean Philosophical Society
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• v.146
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• pp.49-77
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• 2018

This essay examines the ego (I-Subject) problem in Husserl's phenomenology and consists of four parts, as follows. Section I describes the meaning of this research on ego and some important points to note in relation to this study. Section II discusses two aspects of the problem of pure ego, which appears as an ego-problem for the first time. The first aspect is the two opposing positions that Husserl himself took regarding pure ego. Husserl initially rejected pure ego as an object of research in Logische Untersuchungen I (1901) however, he withdrew this position in Logische Untersuchungen II (1913). The second aspect is the content of pure ego that Husserl explored in Ideen I (1913) after he accepted pure ego as a phenomenological problem. The theme of section III is the "theory of three egos" which appeared in Ideen II (1912, 1952). Here, two issues have been noted, one of which is the methodological basis for enabling this theory: the phenomenological "attitude change" (Einstellungsaenderung) and the "Underlying" (Fundierung). The other is the explanation of the content of the three egos: the "physical ego", "personal ego" and the "pure ego". Section IV concerns two themes of the "monadic ego" that appeared in the Cartesianische Meditationen (1931). The first theme is the theoretical premise for the establishment of the monadic ego. In conjunction with this theme, phenomenological-psychological reduction was used as a new method to open up new problem horizons. The second theme brings up the content of the monadic ego, the essence of which can be summarized as follows. 1) This ego is based on a pluralistic and independent ego-concept in which each ego is equal to its own self. 2) It must be asked whether each of the monadic egos is different from one another. 3) The "other" of a certain transcendental ego is not the ego-other relationship but ego-another ego (alter-ego). 4) This phenomenological monadic ego can mutually communicate with alter-egos through empathy, unlike Leibniz's metaphysical monads.

• Journal of Preventive Medicine and Public Health
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• v.36 no.4
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• pp.339-348
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• 2003

Objective : To quantify the economic value of the Sirolimus fluting Stent ($CYPHER^{TM}$) in treating acute coronary heart disease (CMD), and to assist in determining an adequate level of reimbursement for $CYPHER^{TM}$ in Korea. Methods : A decision-analytical model, developed by the Belgium Health Economics Disease Management group, was used to investigate the incremental cost-effectiveness of $CYPHER^{TM}$ versus conventional stenting. The time horizon was five years. The probabilities for clinical events at each node of the decision model were obtained from the results of large, randomized, controlled clinical trials. The initial care and follow-up direct medical costs were analyzed. The initial costs consisted of those for the initial procedure and hospitalization, The follow-vp costs included those for routine follow-up treatments, adverse reactions, revascularization and death. Defending on the perspective of the analysis, the costs were defined as insurance covered or total medical costs (=sum of insurance covered and uncovered medical costs). The cost data were obtained from the administrative data of 449 patients that received conventional stenting from five participating Korean hospitals during June 2002. Sensitivity analyses were peformed for discount rates of 3, 5 and 7%. Since the major clinical advantage of $CYPHER^{TM}$ over conventional stenting was the reduction in the revascularization rates, the economic value of $CYPHER^{TM}$, in relation to the direct medical costs of revascularization, were evaluated. If the incremental cost of $CYPHER^{TM}$ per revascularization avoided, compared to conventional stenting, was no higher than that of a revascularization itself, $CYPHER^{TM}$ would be considered as being cost-effective. Therefore, the maximum acceptable level for the reimbursement price of $CYPHER^{TM}$ making the incremental cost-effectiveness ratio equal to the cost of a revascularization was identified. Results : The average weighted initial insurance covered and total medical costs of conventional stenting were about 6,275,000 and 8,058,000 Won, respectively. The average weighted sum of the initial and 5-year follow-up insurance covered and total medical costs of conventional stenting were about 13,659,000 and 17,353,000 Won, respectively. The estimated maximum level of reimbursement price of $CYPHER^{TM}$ from the perspectives of the insurer and society were $4,126,897{\sim}4,325,161$ and $4,939,939{\sim}5,078,181$ Won, respectively. Conclusion : By evaluating the economic value of $CYPHER^{TM}$, as an alternative to conventional stenting, the results of this study are expected to provide a scientific basis for determining the acceptable level of reimbursement for $CYPHER^{TM}$.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.607-615
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• 2016

This research was conducted to investigate the influence of different kinds of acids added to irrigation water containing high levels of bicarbonate on the growth and daughter plant production during the propagation of 'Seolhyang' strawberry. Fertigation solution was prepared with equal concentrations of essential nutrients as found in Hoagland solution, plus $240mg{\cdot}L^{-1}\;HCO_3{^-}$. The concentrations of $HCO_3{^-}$ in the treatment solution were decreased to $60mg{\cdot}L^{-1}$ by the addition of $HNO_3$, $H_3PO_4$, $H_2SO_4$, $HNO_3+H_3PO_4$, or salicylic acid. The mother plants transplanted to raised beds were treated with a specific treatment solution for 126 days and growth and daughter plant productions were monitored. The fresh weight of mother plants in the -control treatment ($240mg{\cdot}L^{-1}\;HCO_3{^-}$) was significantly lower than those in acid containing treatments. The number of daughter plants produced per mother plant was 13 in the -control treatment, but 19.4, 20.1, 18.6, 22.4, and 18.9 in the treatments of $HNO_3$, $H_3PO_4$, $H_2SO_4$, $HNO_3+H_3PO_4$ and salicylic acid, respectively. The substrate pHs after 126 days of treatment were 8.2 and 7.3 in the -control and salicylic acid treatments, respectively, but 5.5, 5.4, 5.3, and 5.5 in the treatments of $HNO_3$, $H_3PO_4$, $H_2SO_4$, and $HNO_3+H_3PO_4$ treatments, respectively. The tissue Ca and Mg contents of mother plants were significantly higher in +control ($90mg{\cdot}L^{-1}\;HCO_3{^-}$) and various acid blending treatments compared to the -control treatment. By contrast, Ca and Mg contents were not significantly different among treatments with acids. The Fe, Mn, Zn, and Cu contents in plant tissue of -control were also significantly lower than those in all other treatments.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.33-38
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• 2014

Purpose Auto exposure control (AEC) in SPECT/CT automatically controls the exposure dose (mA) according to patient's shape and size. The aim of this study was to evaluate the effect of AEC in SPECT/CT on exposure dose reduction and image quality. Materials and Methods The model of SPECT/CT used in this study was Discovery 670 (GE, USA), Smart mA for AEC; and $^{99m}Tc$ as a radioisotope. To compare SPECT and CT images by CT exposure dose variation, we used a standard technique set at 80, 100, 120, 140 kVp, 10, 30, 50, 100, 150, 200, 250 mA, and AEC at 80, 100, 120, 140 kVp, 10-250 mA. To evaluate resolution and contrast of SPECT images, triple line phantom and flangeless Esser PET phantom were used. For CT images, noise and uniformity were checked by anthropomrphic chest phantom. For dose evaluation to find DLP value, anthropomorphic chest phantom was used and the CT protocol of torso was applied by standard technique (120 kVp, 100 mA) and AEC (120 kVp, 10-250 mA). Results When standard and AEC were applied, the resolutions at SPECT images with attenuation correction (AC) were the same as FWHM by center 3.65 mm, left 3.48 mm, right 3.61 mm. Contrasts of standard and AEC showed no significant difference: standard 53.5, 29.8, 22.5, 15.8, 6.0, AEC 53.5, 29.6, 22.4, 15.7, 6.1 In CT images, noise values at standard and AEC were 15.4 and 18.5 respectively. The application of AEC increases noise but the value of coefficient variation were 33.8, 24.9 respectively, obtaining uniform noise image. The values of DLP at standard and AEC were 426.78 and 352.09 each, which shows that the application of AEC decreases exposure dose more than standard by approximately 18%. Conclusion The results of our study show that there was no difference of AC in SPECT images based on the CT exposure dose variation at SPECT/CT images. It was found that the increased CT exposure dose leads to the improvement of CT image quality but also increases the exposure dose. Thus, the use of AEC in SPECT/CT contributes to obtaining equal AC SPECT images, and uniform noise in CT images while reducing exposure dose.

• The Journal of the Korean Society for Microbiology
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• v.21 no.3
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• pp.311-329
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• 1986

The experimental exposure of animals to sources of ultraviolet radiation (UVR) which emit their energy primarily in the UVB region (280-320nm) is known to result in a number of well-described changes in the recipient's immune competence. Two such changes include a depressed capacity to effectively respond immunologically to transplants of syngeneic UVR tumors and a markedly reduced responsiveness to known inducers of delayedtype (DTH) and contact hypersensitivity (CH) reactions. The results of experiments that were designed to elucidate the mechanisms responsible for UVR-induced immunomodulation have implicated: 1) an altered pattern of lymphocyte recirculation, 2) suppressor T cells(Ts), 3) deviations in systemic antigen presenting cell (APC) potential. 4) changes in the production of interleukin-1-like molecules, and 5) the functional inactivation of epidermal Langerhans cells in this process. The exposure of skin to UVR, therefore, causes a number of both local and systemic alterations to the normal host immune system. In spite of this seeming complexity and diversity of responses, our recent studies have established that each of the UVR-mediated changes is probably of equal importance to creating the UVR-induced immunocompromised state. Normal animals were exposed to low dose UVR radiation on their dorsal surfaces under conditions where a $3.0\;cm^2$ area of skin was physically protected from the light energy. Contact sensitization of these animals with DNFB, to either the irradiated or protected back skin, resulted in markedly reduced CH responses. This was observed in spite of a normal responsiveness following the skin sensitization to ventral surfaces of the UVR-exposed animals. Systemic treatment of the low dose UVR recipients with the drug indomethacin (1-3 micrograms/day) during the UVR exposures resulted in a complete reversal of the depressions observed following DNFB sensitization to "protected" dorsal skin while the altered responsiveness found in the group exposed to the skin reactive chemical through directly UVR-exposed sites was maintained. These studies implicate the importance of EC as effective APC in the skin and also suggest that some of the systemic influences caused by UVR exposure involve the production of prostaglandins. This concept was further supported by finding that indomethacin treatment was also capable of totally reversing the systemic depressions in CH responsiveness caused by high dose UVR exposure (30K joules/$m^2$) of mice. Attempts to analyze the cellular mechanisms responsible established that the spleens of all animals which demonstrated altered CH responses, regardless of whether sensitization was through a normal or an irradiated skin site, contained suppressor cells. Interestingly, we also found normal levels of T effector cells in the peripheral lymph nodes of the UVR-exposed mice that were contact sensitized through normal skin. No effector cells were found when skin sensitization took place through irradiated skin sites. In spite of such an apparent paradox, insight into the probable mechanisms responsible for these observations was provided by establishing that UVR exposure of skin results in a striking and dose-dependent blockade of the efferent lymphatic vessels in all peripheral lymph nodes. Therefore, the afferent phases of immune responses can apparently take place normally in UVR exposed animals when antigen is applied to normal skin. The final effector responses, however, appear to be inhibited in the UVR-exposed animals by an apparent block of effector cell mobility. This contrasts with findings in the normal animals. Following contact sensitization, normal animals were also found to simultaneously contain both antigen specific suppressor T cells and lymph node effector cells. However, these normal animals were fully capable of mobilizing their effector cells into the systemic circulation, thereby allowing a localization of these cells to peripheral sites of antigen challenge. Our results suggest that UVR is probably not a significant inducer of suppressor T-cell activity to topically applied antigens. Rather, UVR exposure appears to modify the normal relationship which exists between effector and regulatory immune responses in vivo. It does so by either causing a direct reduction in the skin's APC function, a situation which results in an absence of effector cell generation to antigens applied to UVR-exposed skin sites, inhibiting the capacity of effector cells to gain access to skin sites of antigen challenge or by sequestering the lymphocytes with effector cell potential into the draining peripheral lymph nodes. Each of these situations result in a similar effect on the UVR-exposed host, that being a reduced capacity to elicit a CH response. We hypothesize that altered DTH responses, altered alloresponses, and altered graft-versus-host responses, all of which have been observed in UVR exposed animals, may result from similar mechanisms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.186-196
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• 2018

Junior colleges are higher education institutions that have played a major role in the economic development of Korea by providing the necessary human resources for its industrial development. Recently, however, they have experienced difficulties due to the reduction in the number of students. Therefore, it is time for junior colleges as a representative higher vocational education institution to change their role in this rapidly changing environment, and adopt a survival strategy through mutual cooperation and competition. The purpose of this study was to analyze the current state of the national health universities, to investigate the policy changes adopted by colleges and universities, and to utilize the results as data. This study analyzed the current status of health science colleges nationwide and investigated the policy changes as well as the directions presented to the colleges, in order to use the results as the basic data to promote the diversification of the class periods and degree programs. This study surveyed 636 professors from health sciences departments and industry workers from May 1 to May 30, 2017. 70.7% of the respondents supported the transition of the existing three-year systems of the health science departments to four-year systems. The reason for this is that it is possible to strengthen the field practice and personality education of the students by having a sufficient number of class periods, and to provide them with an equal educational background. The most anticipated effect of the transition to a four-year system is to improve the social status of medical personnel and to improve the educational environment of the colleges/universities. Moreover, the universities, associations of medical personnel and Ministry of Education are expected to play a leading role in the transition to the four-year system. Based on the results of this study, it was concluded that a more systematic and advanced vocational education system for the training of professional healthcare workers is needed in the upcoming fourth Industrial Revolution era. Also, this transition is expected to actively foster the education of advanced health care workers thanks to the diversification of the degree programs through the adjustment of the class periods which can be completed by general university (4-year) graduates.