• Journal of Gastric Cancer
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• v.8 no.4
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• pp.232-236
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• 2008

Purpose: Laparoscopic surgery for gastric cancer was introduced in the past decade because it was considered less invasive than open surgery, and this results in less postoperative pain, faster recovery and an improved quality of life. Several studies have demonstrated the safety and feasibility of this procedure. We examined the outcome of performing laparoscopic surgery for gastric cancer over the last two year. Materials and Methods: From April 2004 to December 2006, 329 patients with gastric adenocarcinoma underwent a laparoscopy-assisted distal gastrectomy with lymph node dissection. The data was retrospectively reviewed in terms of the clinicopathologic findings, the perioperative outcomes and the complications. Results: The total patient group was comprised 196 men (59.6%) and 133 women (40.4%). The mean BMI was 23.6 and the mean tumor size was 2.7 cm. The mean number of harvested lymph node was 22.7, and this was 18.6 before 30 cases and 23.1 after 30 cases, and the difference was significant (P=0.02). The mean operation time was 180.9 min, and this was than 287.9 min before 30 cases and 170.2 min after 30 cases. After 30 cases, there was a significant improvement of the operation time (P<0.01). The mean incision length after 30 cases was shorter than that before 30 cases (P<0.01). Postoperative complications occurred in 24 (7.3%) of 329 patients and there was no conversion to open surgery. Conclusion: Even though the LADG was accompanied by a difficult learning curve, we successfully performed 329 LADG procedures over the past 2 years and we believe that LADG is a safe, feasible operation for treating most early gastric cancers (EGC).

• 대한공업교육학회지
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• v.39 no.1
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• pp.164-188
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• 2014

The purpose of this study is to investigate the perception of undergraduates of the college of education on the importance of certification areas and factors suggested by the certification system at each department level as well as the college as a whole, in order to come up with measures for further improvement. The specific objectives of this study are first, verifying different perception on the importance of certification areas and factor per department, second, verifying different perception on the importance of certification areas and factor per grade. The population of this study is undergraduates of the college of education at A University, and the survey on the different perception on the importance was conducted on 758 students of 10 departments. Total 800 copies of survey were distributed, and 299 copies or 37.3% were retrieved. First, it was found that undergraduates of the college of education at A University highly recognize the necessity of a new system to produce excellent teachers. when it comes to different department, in the area of teaching personalities, there is difference in the importance of teaching aptitude test and completion of social intelligence development program. In the area of teaching expertise, there is different perception in the importance of completion of curriculum education subjects per major, completion of curriculum contents per major, and participation in teaching demonstration contest. In the area of student guidance expertise, there is difference by department in completion of creative character development related education programs and "teaching practice" course. In the area of communication skills in the information society, minimum score requirement for a second foreign language is considered less important than others. Second, as for grade, freshmen highly recognize the importance of validity of teaching training course, integrity of the course, validity of the teaching training course in producing excellent teachers, graduates' job performing ability development as a teacher, appropriacy of curriculum of the college of education in producing excellent teachers, compared to other grades. In particular, seniors consider the necessity of a new system to produce excellent teachers the most.

• Restorative Dentistry and Endodontics
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• v.36 no.4
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• pp.290-299
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• 2011

Objectives: The usage of fluoride varnish for a moderate to low caries-risk group has not been well validated. This study aimed to evaluate the preventive and therapeutic efficacies of fluoride varnish on the initiated root caries. Materials and Methods: Ten premolars were sectioned into quarters, further divided into two windows, one of which was painted with Fluor Protector (1,000 ppm fluoride, Ivoclar Vivadent). An initial lesion with a well-preserved surface layer was produced by pH cycling. Scanned line analysis using energy dispersive spectrometry determined the weight percentages of Ca and P in the demineralized layer. Scanning Electron microscopy and confocal laser scanning microscopy (CLSM) evaluated the varnish-applied root surfaces. Results: The mean lesion depth (SD) was 12.3 (2.6) ${\mu}m$ (single cycling) and 19.6 (3.8) ${\mu}m$ (double cycling). Double cycling extended the lesion depth, but induced no more mineral loss than single cycling (p < 0.05). The mean weight percentages of Ca and P between groups with and without varnish were not significantly different (p < 0.05). A CLSM showed varnish remained within 15 ${\mu}m$ of the surface layer. Conclusions: When a mild acid challenge initiated root tissue demineralization, the application of low-concentration fluoride varnish did not influence the lesion depth or the mineral composition of the subsurface lesion.

• Korean Journal of Environmental Agriculture
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• v.34 no.1
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• pp.6-13
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• 2015

BACKGROUND: Most of the tailings have been left without any management in abandoned metalliferous mines and have become the main source of heavy metal contamination for agricultural soils and crops in the these areas. METHODS AND RESULTS: This experiment was carried out to investigate the assessment of the heavy metal contamination in paddy soils located on downstream of the closed metalliferous mine. The average total concentrations of cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and arsenic (As) in paddy soils were 8.88, 56.7, 809, 754, and 37.9 mg/kg, respectively. Specially, the average concentrations of Cd, Pb and Zn were higher than those of warning criteria for soil contamination(4 mg/kg for Cd, 200 mg/kg for Pb, and 300 mg/kg for Zn) in agricultural soil established by Soil Environmental Conservation Act in Korea. The proportions of 0.1 M HCl extractable Cd, Cu, Pb, Zn, and As concentration to total concentration of these heavy metals in paddy soils were 27.7, 21.3, 35.1, 13.8 and 10.5%, respectively. The pollution index of these five metals in paddy soils ranged from 0.42 to 11.92. Also, the enrichment factor (EFc) of heavy metals in paddy soils were in the order as Cd>Pb>Zn>Cu>As, and the enrichment factor in paddy soil varied considerably among the sampling sites. The geoaccumulation index (Igeo) of heavy metals in soils were in the order as Cd>Pb>Zn>Cu>As, specially, the average geoaccumulation index of Cd, Pb, and Zn (Igeo 2.49~3.10) were relatively higher than that of other metals in paddy soils. CONCLUSION: Based on the pollution index, enrichment factor, and geoaccumulation index for heavy metal in paddy soils located on downstream of closed metalliferous mine, the main contaminants are mine waste materials and mine drainage including mine activity.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.161-167
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• 2015

BACKGROUND: For the heavy metal cotamination sites, it is very important to estimate the human bioavailability quotients for heavy metals in paddy soils released from mine tailings, which is a major source of contamination in Korea, and to assess the human health risks of heavy metals. METHODS AND RESULTS: This experiment was carried out to investigate the human bioavailability quotient of the heavy metals in paddy soils below part of the closed metalliferous mine. For estimating the human bioavailability quotients for heavy metals, 30 paddy soils below part of the closed mine were collected, and analyzed for Cd, Cu, Pb, Zn, and As using simple bioavailability extraction test(SBET). The quantities of Cd, Cu, Pb, Zn and As extracted from paddy soils below part of the mine by using the SBET analysis were 28.1, 17.3, 34.1, 14.6 and 2.3% respectively. Specially, the maximum values of Cd, Pb and Zn were 73.3, 81.5 and 58.1% of human bioavailability quotient, respectively, and varied considerably among the sampling sites. The human bioavailability quotient of Cd, Cu, Pb and Zn in soils near the closed mine showed significant positive correlation among soil pH value, O.M. and Ex. Ca. contents, while it correlated negatively between soil Ex. K and Ex. Mg contents in paddy soils. Also, its of Cd, Cu, Pb and Zn in paddy soils showed significant positive correlation with 0.1M HCl extractable and total contents, while in soils, it correlated negatively with As content in soil near the closed mine. CONCLUSION: The results of the simple bioavailability extraction test (SBET) indicate that regular ingestion of soils by the local population could be closed a potential health threat due to long-term heavy metals exposure in these mine areas.

• Korean Security Journal
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• no.28
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• pp.103-130
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• 2011

This study is the research of enterprise security for raising the profitability and stability of Korean companies in global business environment and strategic cooperation of business. As the scientific technology gets complicated as day goes by and new competitors appear regardless the border in the modern business environment, the situation happens frequently which the huge company hands over their market to the new one armed with the innovative thinking overnight. To survive such new environment, the answer is the change of paradigm regarding business management method at the new point of view. With the low level of security risk management of Korean companies which stick to old habit, the security management which helps the companies secure profits is not affordable. The global village where the population of 7 billions live in 21st century is facing up to the rapid ecological adaptation. The rapid change of climatic environment creates the hundreds of thousands of sufferers in a moment, and we have been watching the millions of livestock are buried alive due to new contagious disease everyday. Such change encourages the humans in global village to change the basic way of living. The business ecosystem which is the basic root for economic life cannot be an exception. To survive the business environment of 21st century, the security risk management at management level is required and the reporting line of companies should be established newly for raising business competing power through security risk management. The companies should bear in mind that they can be disappeared into our old memories overnight if they are not sensitive to the changing environment. Out of new risks for the modern companies, the field especially Korean companies are dealing easily is the security risk. Not like past, the security risk which's size is much more massive and its propagation velocity is very fast is the one of important business risks which the management should take care. Out of security risks which influence on the modern companies significantly, the brand of companies, protection of their reputation, continuity of production and operation and keeping customer's trust are prior to the others. This study offered the suggestion regarding enterprise security and the strategic cooperation of business to deal with such security risk effectively.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.30-38
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• 2008

Petroleum-based resin adhesives have extensively been used for the production of wood panels. However, with the increase of manufacturing cost and the environmental issue, such as the emission of volatile organic compounds, of the adhesive resins, it is necessary to be developed new adhesive systems. In this study, the potential of okara, which is a residue wasted from the production of tofu, for the development of bio-based adhesives was investigated. At first, the physical and chemical properties of okara were examined. After okara was hydrolyzed in acidic and/or alkaline solutions, okara-based adhesive resins were formulated with the mixtures of the okara hydrolyzates and phenol formaldehyde (PF) prepolymer. The adhesive resins were used for the fabrication of plywood panels, and then the adhesive strength and formaldehyde emission of the plywood panels were measured to examine the applicability of the resin adhesives for the production of plywood panels. The solids content and pH of the okara used in this study were around 20% and weak acidic state, respectively. In the analysis of its chemical composition, the content of carbohydrate was the highest, and followed by protein. The shear strengths of plywood fabricated with okara-based resin adhesives exceeded a minimum requirement of KS standard for ordinary plywood, but its wood failure did not reach the minimum requirement. In addition, the formaldehyde emissions of all plywood panels were higher than that of E1 specified in the KS standard. Based on these results, okara has the potential to be used as a raw material of environmentally friendly adhesive resin systems for the production of wood panels, but further researches - biological hydrolysis of okara and various formulations of PF prepolymer - are required to improve the adhesive strength and formaldehyde emission of okara-based resin adhesives.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.732-737
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• 2009

Background: Many video-assisted thoracic surgery (VATS) lobectomies are performed as a potential alternative to thoracotomy despite the controversy about the safety and the associated morbidity/mortality rates. Material and Method: Between November 2006 and August 2008, we performed 87 lobectomies (VATS 36, Thoracotomy 51) and we retrospectively reviewed the surgical treatment results. A VATS lobectomy was performed by a 4~5 cm thoracotomy without rib spreading and this included anatomic hilar dissection, individual vessel and bronchus stapling and lymph node dissection. Result: We studied 52 male and 35 female patients whose age ranged from 6 to 79 (average age: $59.8{\pm}15.0$ years). The cases were diagnosed with lung cancer (66) (SQC 24, ADC 38, others 4), pulmonary metastasis (2), carcinoid (2) and benign diseases (17). There was no intraoperative death. Postoperative complications were seen in 5 (15.6%) VATS and 33 (64.7%) thoracotomies, and perioperative death caused by adult respiratory distress syndrome occurred in 1 (2.8%) VATS and 3 (5.9%) thoracotomies. Three patients Underwent conversion to thoracotomy (8.3%). The mean time to chest tube removal was 6 days for VATS and 9.4 days for thoracotomy (p<0.001), and the mean length of the hospital stay was 8 days for VATS and 12.8 days for thoracotomy (p<0.001). Conclusion: VATS lobectomy can be performed safely with low morbidity/mortality rates. Furthermore, all the patients benefited from earlier postoperative rehabilitation and less pain and they were candidates for an earlier return to normal activities.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.216-222
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• 2002

Field experiments were conducted to investigate the effect of various cultural practices on methane($CH_4$) emission in tillage and no-tillage practice in a clayey paddy soil from 1998 to 2000. The factors evaluated in tillage and no-tillage methods were types of nitrogen fertilizers, application method of chemical fertilizers, rice straw application and cultivation method. Of the nitrogen fertilizers, the amount of $CH_4$ emission in ammonium sulfate plot was the lowest, regardless of tillage and the application method. 26.4~41.1% of reduction by ammonium sulfate compared with urea. But in no-tillage which have problem of poor rice yield than tillage, coated urea was more effective nitrogen fertilizer because that showed similar $CH_4$ emission and highest rice yield at 80% of dosage of nitrogen. No-tillage plot emitted lower $CH_4$ than tillage plot where the fertilizers were incorporated. On the contrary, no-tillage plot showed a little higher $CH_4$ emission compared with tillage plot for the surface application. When rice straw was applied, no-tillage practice reduced methane emission by 26.6% compared with tillage practice, but showing a little difference of 10.7% in no application. With cultivation method, no-tillage practice reduced methane emission 26.6% compared with tillage for the 30-d-old seedling transplanting. But for the dry direct seeding practice, no-tillage was a less effective because considerable amounts of rice straw incorporated by tillage were more decomposed aerobically in the soil and emitted as $CO_2$ to the atmosphere with flooding in no-tillage soil.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.607-616
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• 2013

Light with two faces, beneficial and harmful effects is an important signal for every living cell. Optimal adaptation to light environment enhances the fitness of an organism and survival in nature. Understandings of light quality and plant growth provide with the economical guides for artificial light sources like LEDs. Compared with those under white light, the 1 week seedlings of Chinese cabbage (Brassica rapa) under monochromic red and blue light showed normal development and growth. In contrast to extremely long and etiolated hypocotyls of the seedlings under dark, those under far-red etiolated were extremely short. Based on the microarray analysis, blue light induced the vigorous development and growth and two fold changes of transcripts than red light condition. To have insight of gene products under different light qualities conditions, GO term enrichments were calculated and each gene according to their GO terms were categorized. The blue and red lights affected the expressions of genes related to biological process. Especially, the genes related to metabolic process and developmental process and plastid and chloroplast in the cellular component category were induced under blue light. This study provided the molecular biological evidence for various light qualities on the growing process of B. rapa.