• The Journal of Korean Medical History
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• v.18 no.2
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• pp.197-227
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• 2005

Heojun was the top scientist on Medicine in the 16th and 17th centuries and wrote the Dongeubogam describing the top-level medical theory and technology. So far, his outlook on nature has been disregarded even though his medicine is still effective. Through this study, I would like to know if his outlook on nature as well as his medicine is still effective. The conclusions are as follows: 1. According to his output, the origin of the universe started from the spinning of One Gi(一氣) which is quite different from Hawking's theory. Hawking assumed that the origin of the universe started from the Big-bang and will end to the Big-crunch. However, the current report on the origin of a star is quite similar to Heojun's theory and we acknowledge that his view on the origin of the universe is still effective. 2. According to his output, the universe repeats expanding and contracting forever while Hawking assumed it will come to the end, the Big-crunch, based on the expanding universe theory. Some scientists assists that Hawking's assumption should have some contradictions. Now, we acknowledge that Heojun's universal cycling theory which corresponds with modern physical theories is still effective, which would lead to a new environmental movement. 3. His view on the structure of the universe is quite different from the output of the current science, which results from his thought that the nature should be reviewed from the point of human's view. His view on the structure will be able to be updated based on the output of the current science. 4. The universe analogy started from the East Asian area as well as the Greek and Roman area in the ancient. The idea has disappeared since the scientific revolution era in the West while the idea has been deepened and abundant in the East and has become one of the major philosophical bases. Heojun emphasized its importance from the beginning of his book. 5. The nation analogy has been popular all times and places. According to his output, governing a country is like controlling one's body. 6. According to Needham's output, the universe analogy and the nation analogy were based on the ancient developed alchemy. And Harper assumed that Taiosm was based on the macrobiotic hygiene which was developed by the ancient developed alchemists. We acknowledge that xian(仙) cult, macrobiotic hygiene, medicine, alchemy and the ancient philosophy started from our ancients. Heojun's output restored our ancient tradition by combining the macrobiotic hygiene and philosophy with medicine. 7. Roughly predicting yearly weather would be unacceptable by the current scientist but Heojun's yearly weather forecast is still used in the clinic and seems effective to prepare from any epidemic disease. 8. 'Day and Night' and Four seasons are the most important factors to the macrobiotic hygiene according to the Dongeubogam. The new environmental movements should be based on the most important factors, otherwise the human beings as well as the environment would fail to survive. 9. Wind, Coldness, Heat, Humidity, Dryness and Fire represents weather. The six weather factors represent one of six phases of a year which is decided by the areal factors. Heojun preferred the six factors generated in the body itself to them from the outside. He thought a human being was a universe and the six factors generated in the body responded to the factors of the outside. 10. According to his output, Heat and Humidity are the most important factors which make a human being ill. 11. Life span, disease, food, and dwelling are dependent upon the geographical feature, according to Heojun's output. In addition, one's appearance and his five viscera and the six entrails depend on the food as well as the geographical feature. 12. Heath is related with the environment and they effects upon each other. If one is weak, he will be deeply effected by the nature. On the other hand, if one is strong, he will effect on the nature. That's why people live together. 13. According to Heojun's work, the society is an important factor comprising the environment. During a peaceful era, the society becomes stable and human beings are stable as well while they will be on fire during a chaotic era. 14. Medicine deals with human beings who live in the nature, so any medical book cannot be excellent unless it has any description on the nature. Heojun's outlook on the nature turned out to be logical and suitable even from the point of the current view and it is still effective as if his clinical knowledge and technology are still effective. Something unsuitable may be substituted with the output of the current science.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.12-25
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• 2004

Physicochemical parameters, plankton biomass, and sediment were surveyed from 1998 to 2000 at two months interval in a eutrophic coastal lagoon(Lake Hwajinpo, Korea). The lake is separated from the sea by a narrow sand dune. Littoral zone is well vegetated with leafing-leaved aquatic plants. The lake basin is divided into two subbasins by a shallow sill. It has intrusion of seawater by permeation and stormy waves. Stable chemoclines are formed by salinity difference at 1m depth all the year round. DO was often very low (< 1 mg$O_2\;L^{-1}$) at hypolimnion. Temperature inversions were observed in November. Nitrate and ammonium concentrations were very low(< (1.1 mgN $L^{-1}$), even though TN was usually 2.0 ${\sim}$ 3.5 mgN $L^{-1}$. TN/TP was generally lower than the Redfield ratio. Transparency was 0.2 ${\sim}$ 1.7 m, and COD, TP, and TN of sediment were 3.1 ${\sim}$ 40.3 mg$O_2\;g^{-1}$, 0.91 ${\sim}$ 1.39 mgP $g^{-1}$, and 0.34 ${\sim}$ 3.07 mgN $g^{-1}$, respectively. Phytoplankton chlorophyll- a concentrations were mostly over 40 mg $m^{-3}$. Two basins showed different phytoplankton communities with Oscillatoria so., Trachelomonas sp., Schizochlamys gelatinosa, and Anabaena spiroides dominant in South basin, and with Trachelomons sp., Schroederia so., schizochlamys gelatinosa, and Trachelomonas sp. dominant in the North basin. The seasonal succession of phytoplankton was very fast, possibly due to sudden changes in physical conditions, such as wind, turbidity, salinity and light.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.66-75
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• 2008

This study examined the influence of the apical sizes on the sealing ability of a root canal filling. Thirty-six single rooted teeth with a single canal were divided into 3 groups (n = 12) and instrumented with either the $Profile^{(R)}$ or $LightSpeed^{(R)}$ system to achieve three different apical sizes (master apical file [MAF] of #25, #40, or #60). The teeth were filled with gutta perch a using a modified continuous wave technique. The level of microleakage was determined by immersing ten teeth from each group into India ink for 1 week followed by clearing with nitric acid, ethyl-alcohol, and methylsalicylate. The microleakage was measured using vernier calipers. The data was analyzed statistically using Kruskal-Wallis one-way ANOVA and a Student-Newman-Keuls Method. Two teeth from each group were sectioned horizontally at 1, 2, 3 and 4 mm from the apex in order to observe a cross section. The apical size was significantly (p < .05) influenced the level of microleakage. In the Student-Newman-Deuls Method, MAF sizes of #25 and #40; and MAF sizes of #25 and #60, respectively showed a statistically significant difference. There was no significant difference between #40 and #60. In most cross sections, oval-shaped canals were observed, and the irregularity of the internal surface increased with decreasing apical size. There was also an increase in the area of recess, which is the area where the canal space is not filled with either gutta-percha or sealer. When the root canals are filled using a modified continuous wave technique, canal filling with more consistent and predictable outcome may be expected as the apical preparation size is increased.

• Quality Improvement in Health Care
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• v.10 no.2
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• pp.176-189
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• 2003

Background : Gastric cancer is the most common malignant tumor in Korea. Surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for reducing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and the unplanned readmission rate between the pre-pathway group (n=67) and the post-pathway group (n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days (p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was not statistically significant (p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group and 0% in the post-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korean hospital settings.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.207-214
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• 2009

Purpose: Subtotal distal gastrectomy has been accepted as the standard treatment for early gastric cancer that's developed on the gastric body. EMR and ESD have been introduced to minimize the incidence of postgastrectomy syndrome, but these procedures can not detect lymph node metastasis and they have a risk for gastric perforation. Segmental gastrectomy has recently been applied for treating early gastric cancer, but its usefulness has not been clarified. The aim of this study was to compare segmental gastrectomy and distal gastrectomy with Billroth I reconstruction for treating early gastric cancer that's developed on the gastric body. Materials and Methods: We performed a retrospective review of all the patients who were diagnosed as having early gastric cancer that developed on the gastric body at Chungnam National University Hospital from January 2004 through July 2007. During this period, 41 patients received segmental gastrectomy and 40 patients underwent subtotal distal gastrectomy. All the patients were studied via a biannual review of the body systems, a physical examination, endoscopy, computed tomography and the laboratory findings. Results: There were no significantly differences of the clinicopathologic characteristics between the two groups. The changes of the nutritional status (Hb, TP, Alb and TC) and the body weight change were not significantly different between the 2 groups. There were significantly more residual food in the SG group than that in the SDG group (RGB classification, Residual>Grade 2), but there were no differences for epigastric discomfort (P>0.05). Esophagitis developed at a similar rate for both two groups (LA classification, >Grade A), and bile reflux was found in only one patient of each group. Conclusion: We expected the reduction of esophagitis and gastritis and the improvement of nutritional status according to the type of procedure. Yet the results of our study showed no significant differences between the two study groups. More patients and a longer follow up time are needed for determining the advantage sand disadvantages of segmental gastrectomy.

• Research in Community and Public Health Nursing
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• v.4 no.1
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• pp.67-76
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• 1993

The purpose of this study was to find the status of health examination and health management of industrial companies located in Taegu and Kyung book areas. It will provide basic information for the provision of effective health management of industrial workers. 49 companies were selected as a study sample group, and data was collected by using a structured Questionnaire which was developed by the members of the Community Health Nursing Academy of Korean Nursing. The health managers of the companies filled out the Questionnaire. The data was gathered from Dec 20, 1992 to Jan 20. The results of the study was as follows : 1. The Study sample showed 85.7% manufacturing companies having 300 or more workers. 2. All the companies had health managers, and companies which had 1,000 or more workers had industrial physicians and nurses. Only 12.2% of the industrial physicians were full time employees, and almost all industrial nurses were full time employees. Except for industrial physicians and nurses, the proportion of hygienists (6.1%), nurses aids (4.1%), and environmental engineers (22.4%) with full time employment statuss was very low. The mean age of industrial physicians was 49.2 while that of industrial nurses was 27.2. The length of work experiences currently ranges for 1 to 3 years for all health workers: physicians, nurses, hygienists, and environmental engineers. 3. Health examination and follow up care 94.31% took general health examinations. Of those, the proportion of the workers, who were determined as C grade(in need of close examination) was 43.86%. The proportion of the workers who were determined as D grade was 22.19%. 13.28% of the workers evaluated at the D grade were taken as a gauge for temporary leave from work. While 8.7% and .09% of them were taken as gauge for a change in job, and or shortening work hours respectively. The proportion of workers who must have taken special examination was 65.04% and of those the proportion of the workers who actually took, the examination was 98.55%. 75% of the workers who were recommended for follow up care were given follow up care. The special examinations were done the most frequently to detect the effects of physical agents (59.2%). Direct notice to individual workers was used the most frequently as a method of notification after a special examination (61.2%). The length of time taken to receive the result of a special examination was less than 1 month (38.9%) and 36.7% had taken up to two months (36.7%.). Most results of special examination were obtained within 2 months. The referral rate of consulting special examination by health managers was estimated at 95.9%. 4. 89.8% of the companies had. their own company dispensaries and 75.5% of those. had separate dispensaries. 32.7% of the companies designated local clinics for health management of workers. Industrial nurses performed health examination the most frequently(1.4 points). Health appraisal for work places were. done the least(0.83 points).

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.535-543
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• 2008

Purpose: The objective of this study was to compare the bonding characteristics of a new self-adhesive resin cement to dentin, which does not require bonding and conditioning procedure of the tooth surface, and conventional resin cement. The effect of phosphoric acid etching prior to application of self-adhesive resin cement on the shear bond strength was also evaluated. Material and methods: Fortyfive non-carious human adult molars extracted within 6 months were embedded in chemically cured acrylic resin. The teeth were ground with a series of SiC-papers ending with 800 grit until the flat dentin surfaces of the teeth were exposed. The teeth were randomly divided into 3 experimental groups. In group 1, self-adhesive resin cement, RelyX Unicem (3M ESPE, Seefeld, Germany) was bonded without any conditioning of teeth. In group 2, RelyX Unicem was bonded to teeth after phosphoric acid etching. For group 3, Syntac Primer (Ivoclar Vivadent AG, Schaan, Liechtenstein) was applied to the teeth before Syntac adhesive (Ivoclar Vivadent AG, Schaan, Liechtenstein) and Helibond (Ivoclar Vivadent AG, Schaan, Liechtenstein) followed by conventional resin cement, Variolink II (Ivoclar Vivadent AG, Schaan, Liechtenstein). To make a shear bond strength test model, a plastic tuble (3 mm diameter, 3 mm height) was applied to the dentin surfaces at a right angle and filled it with respective resin cement, and light-polymerized for 40 seconds. All the specimens were stored in distilled water at $37^{\circ}C$ for 24 hours before test. Universal Testing Machine (Z020, Zwick, Ulm, Germany) at a cross head speed of 1 mm/min was used to evaluate the shear bond strength. The failure sites were inspected under a magnifier and Scanning Electron Microscope. The data was analyzed with One way ANOVA and Scheffe test at ${\alpha}$= 0.05. Results: (1) The shear bond strengths to dentin of RelyX Unicem was not significantly different from those of Variolink II/Syntac. (2) Phosphoric acid etching lowered the shear bond strength of RelyX Unicem significantly. (3) Most of RelyX Unicem and Variolink II showed mixed fractures, while all the specimens of RelyX Unicem with phosphoric acid etching demonstrated adhesive failure between dentin and resin cement. Conclusion: Shear bond strength to dentin of self-adhesive resin cement is not significantly different from conventional resin cement, and phosphoric acid etching decrease the shear bond strength to dentin of self-adhesive resin cement.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.260-266
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• 2003

In this study bacterial community was analyzed to evaluate the impacts of long-term use of agricultural chemicals on a soil ecosystem as well as to obtain fundamental data on the relationship. Sequences of 16S rRNA clones from a non-agricultural site and a tangerine orchard soil which has a history of long-term use of agricultural chemicals over 30 years were analyzed. This revealed that bacterial community containing 5 divisions and 18 genera was distributed in a tangerine orchard soil, while bacterial community containing 9 divisions and 44 genera was distributed. In a tangerine orchard soil site, the most abundant bacteria in subdivision level were placed into Proteobacteria γ group which occupied 56% of total clones. The other bacterial clones from the ocrhcard soil exposed to agricultural chemicals over 30 years were Acidobacteria group (25%), Fimicutes group (5%), Planctomycetes group (2%), Proteobacteria α (1%), δ group (1%), and Cyanobacteria group (1%). Whereas, the clones were from the non-agricultural site were distributed among the division or subdivision Acidobacteria group (14%), Planctomycetes group (13%), Proteobacteria α (10%), β (9%), δ (9%), Fimicutes group (8%), Verrucomicrobia group (8%), Actinobacteria group (6%), Proteobacteria γ group (3%), Bacteroidetes group (3%), Gemmatimonadetes group (3%), and Cyanobacteria group (1%). This finding suggests the possibility that long-term application of agricultural chemicals or fertilizers on a tangerine orchard might result in drastic reduction or alteration in the composition of the bacterial community in the contaminated soil site.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.229-234
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• 2001

The EDXRF(Energy Dispersive X-ray Fluorescence Spectrometer) technique was applied to the determination of heavy metals in welding fume. The EDXRF method designed in this study was a non-destructive analysis method. Samples were analyzed directly by EDXRF without any pre-treatment such as digestion and dilution. The samples used to evaluate this method were laboratory samples exposed in a chamber connected with a welding fume generator. The samples were first analyzed using a non-destructive EDXRF method. The samples subsequently were analyzed using AAS method to verify accuray of the EDXRF method. The purpose of this study was to evaluate the possibility of the non-destructive analysis of heavy metals in welding fume by EDXRF. The results of this study were as follow: 1.When the samples were collected under the open-face sampling condition, a surface distribution of welding fume particles on sample filters was uniform, which made non-destructive analysis possible. 2. The method was statistically evaluated according to the NIOSH(National Institute for Occupational Safety and Health) and HSE(Health and Safety Executive) method. 3. The overall precision of the EDXRF method Was calculated at 3.45 % for Cr, 2.57 % for Fe and 3.78 % for Mn as relative standard deviation(RSD), respectively. The limits of detection were calculated at $0.46{\mu}g$/sample for Cr, $0.20{\mu}g$/sample for Fe and $1.14{\mu}g$/sample for Mn, respectively. 4. A comparison between the results of Cr, Fe, Mn analyzed by EDXRF and AAS was made in order to assess the accuracy of EDXRF method. The correlation coefficient between the results of EDXRF and AAS was 0.9985 for Cr, 0.9995 for Fe and 0.9982 for Mn, respectively. The overall uncertainty was determined to be ${\pm}12.31%$, 8.64 % and 11.91 % for Cr, Fe and Mn, respectively. In conclusion, this study showed that Cr, Fe, Mn in welding fume were successfully analyzed by the EDXRF without any sample pre-treatment such as digestion and dilution and a good correlation between the results of EDXRF and AAS was obtained. It was thus possible to use the EDXRF technique as an analysis method of working environment samples. The EDXRF method was an efficient method in a non-destructive analysis of heavy metals in welding fume.