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Effect of Garlic Stalk Silage on Performance and Carcass Characteristics of Hanwoo Steers (마늘대 사일리지 급여가 한우거세우의 성장 및 도체특성에 미치는 영향)

  • Chu, G.M.;Lee, H.J.;Park, J.S.;Cho, H.W.;Ahn, B.H.
    • Journal of Animal Science and Technology
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    • v.45 no.6
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    • pp.1007-1018
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    • 2003
  • This study was conducted to investigate the effect of feeding of garlic stalk silage on performance and carcass characteristics of Hanwoo steers. Feeding trial was conducted with 27 heads of Hanwoo steers and these animals were divided into two groups of control(rice straw) and garlic stalk silage. Animals consuming rice straw were fed concentrates and rice straw for 22 months from the 5 months of age and animals consuming garlic stalk silage were fed concentrates, rice straw and garlic stalk silage for 22 months from the 5 months of age. Animals fed rice straw and garlic stalk silage were fed 1.34 and 1.47, 1.69 and 1.74, 1.65 and 1.66% concentrates to body weight for the growing period, fattening period and finishing period, respectively. Animals fed rice straw and garlic stalk silage as roughage sources were fed 1.37 and 1.38, 0.65 and 0.63, 0.43 and 0.43% roughages to body weight for the growing period, fattening period and finishing period, respectively. Also, animals fed garlic stalk silage were offered 0.22 and 0.33% garlic stalk silage to body weight for the fattening and finishing period, respectively. Animals fed rice straw and garlic stalk silage as a roughage sources did not differ in average daily gain during the whole feeding periods. Animals of control group consumed less concentrates and roughage than those fed garlic stalk silage during the whole feeding periods. However, feed efficiency was not significantly different between both treatments. Beef yield including backfat thickness, eye muscle area and carcass weight was slightly lower in the animals fed garlic stalk silage than in the animals fed rice straw even though there were no differences between both treatments. However, beef quality including beef color, fat color, texture, maturity and marbling score was slightly higher in the garlic stalk silage-fed animals than in the animals fed rice straw although there were not statistically different between both treatments. Animals consuming garlic stalk silage was significantly(p<0.05) lower in shear value than those fed rice straw. Amino acid composition including essential amino acid and non-essential amino acid was not different between animals fed rice straw and garlic stalk silage. Eye muscle area of animals fed garlic stalk silage contained slightly higher oleic acid, less linoleic acid and arachidonic acid and more linolenic acid than that of animals fed rice straw only as a roughage sources. So eye muscle area of animals fed garlic stalk silage contained more mono-unsaturated fatty acid than that of animals fed rice straw and $\omega$6/$\omega$3 ratio was narrower in the animals fed garlic stalk silage than in the animals fed rice straw. Economic income was higher by 20% in the animals fed garlic stalk silage than in the animals fed rice straw. Therefore, It may be concluded that feeding of garlic stalk silage as a roughage sources to steers during the fattening period seems to improve meat quality, fatty acid composition and economic income.

Relationship between Parental Career Support, Career Self-Regulation, and Career Identity - with Student Dep. of Radiologic Technology - (부모진로지지와 진로자기조절, 진로정체감의 관계 - 방사선과 학생 대상 -)

  • Kim, In-Sook;Lee, In-Ja
    • Journal of radiological science and technology
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    • v.38 no.3
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    • pp.295-304
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    • 2015
  • This study intended to examine the correlation of career self-regulation (plan and check-up, positive thinking, career feedback, environment formation for career) and career identity (career decision, indecisiveness, career indecision) caused by parental career support (informative, emotional, financial, and empirical) among freshmen, sophomores, and juniors in the radiotechnology department. For assessment, a survey was conducted and according to the results, there existed correlation as follows. Regarding parental career support, emotional support is plan and check-up (r=.25, p<.001), Career feedback (r=.54, p<.001), and positive thinking (r=.46, p<.001) showed high positive correlation while informative support showed correlation in all factors showing high correlation with environment formation for career (r=.22, p<.001), plan and check-up (r=.20, p<.001), career feedback (r=.24, p<.001), and positive thinking (r=.26, p<.001). Financial support career feedback (r=.33, p<.001) and positive thinking (r=.34, p<.001) showed somewhat higher correlation. All factors of environment formation for career (r=.18, p<.001), plan and check-up (r=.25, p<.001), career feedback (r=.37, p<.001), and positive thinking (r=.30, p<.001) showed high correlation. Informative support showed high correlation only with career decision (r=.27, p<.001) and financial support also showed high correlation only with career decision (r=.18, p<.001). Also, empirical support was somewhat highly correlated only with career decision (r=.23, p<.001). Regarding school-year difference depending on parental career support, there was significant difference between emotional support (F=8.52, p<.001), financial support (F=8.97, p<.001), and empirical support (F=5.36, p<.05) while informative support was dismissed. Regarding school-year difference depending on career self-regulation, there was significant difference between career feedback (F=8.48, p<.001) and positive thinking (F=16.29, p<.001) while environment formation for career and plan and check-up were dismissed. Regarding school-year difference depending on career identity, there was significant difference between career indecision (F=4.01, p<.05) and career decision (F=11.72, p<.001) while indecisiveness was dismissed. According to the analysis results, parents' active support to their child like respecting and listening to their opinion on career, provision of career related experience or information, and provision of necessary financial aid for their study or academic preparation made the students plan and exploring their career, examine accomplishment progress, have positive idea to realize their objectives. In addition, the students were able to establish the objective of their career by forming the environment that helped them realize their objectives by seeking advices and encouragement from surroundings. Meanwhile, the parents' attitude to respect and listen to their child's career related opinion affected their career decision and indecision. Although informative support helped the students' career decision, financial and empirical support caused effect only to career decision.

A Study on the Timing and Method of the Final Price of Air Ticket in Computerised Booking System (인터넷 항공권 예약시스템에서의 '최종가격' 표시시기와 방법 - 2015년 1월 15일 EU사법재판소 C-573/13 판결을 중심으로 -)

  • Sur, Ji-Min
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.327-353
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    • 2017
  • The issue submitted to the Court of Justice on the merits of case C---573/13 originated from a claim brought in the context of a dispute between Air Berlin and the German Federal Union of Consumer Organisations and Associations. The challenge concerned the way in which air fares were displayed in Air Berlin's computerised booking system. The system was organised in such a way that, after selecting a date and a departure airport, one would find all possible flight connections in a summary table. However, the final price of the ticket was displayed only for the clicked connection, and not for all connections, thus preventing customers from being able to compare such price with the prices of other connections. The German Federal Union took the view that this practice did not meet the requirements laid down by Article 23 of Regulation (EC) No. 1008/2008, which requires transparency in the prices set for air services. This led the German State to bring an injunctive action to cause Air Berlin to discontinue said practice. The claim was upheld at both the application and appeal stage of the relevant proceedings. Subsequently, Air Berlin submitted the matter to the German Federal High Court, which decided to stay the proceedings and ask for a preliminary ruling from the Court of Justice as to 1. whether Article 23 of Regulation (EC) No. 1008/2008 must be interpreted as meaning that, during the computerised booking process, the final price to be paid must be indicated at all times when prices of air services are shown, including when they are shown for the first time; and 2. whether, during the computerised booking process, the final price must be indicated only for the air service specifically selected by the customer or for each air service shown. In a nutshell, the Court, by the here---discussed judgment determined that Article 23 of Regulation (EC) No. 1008/2008 must be interpreted as meaning that, in the context of a computerised air ticket booking system, the final price to be paid must be indicated not only for the air service specifically selected by the customer, but also for each air service in respect of which the fare is shown. Clearly the above judgment will place air companies under an obligation to update and adjust (when needed) their computerised ticket booking and payment systems, in consideration of the primary need for consumers to be aware at all times of the actual price payable for a ticket and be able to compare the price of the service selected with the prices for other air services in respect of which the fare is shown.

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Analysis and Implication on the International Regulations related to Unmanned Aircraft -with emphasis on ICAO, U.S.A., Germany, Australia- (세계 무인항공기 운용 관련 규제 분석과 시사점 - ICAO, 미국, 독일, 호주를 중심으로 -)

  • Kim, Dong-Uk;Kim, Ji-Hoon;Kim, Sung-Mi;Kwon, Ky-Beom
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.225-285
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    • 2017
  • In regard to the regulations related to the RPA(Remotely Piloted Aircraft), which is sometimes called in other countries as UA(Unmanned Aircraft), ICAO stipulates the regulations in the 'RPAS manual (2015)' in detail based on the 'Chicago Convention' in 1944, and enacts provisions for the Rules of UAS or RPAS. Other contries stipulates them such as the Federal Airline Rules (14 CFR), Public Law (112-95) in the United States, the Air Transport Act, Air Transport Order, Air Transport Authorization Order (through revision in "Regulations to operating Rules on unmanned aerial System") based on EASA Regulation (EC) No.216/2008 in the case of unmanned aircaft under 150kg in Germany, and Civil Aviation Act (CAA 1998), Civil Aviation Act 101 (CASR Part 101) in Australia. Commonly, these laws exclude the model aircraft for leisure purpose and require pilots on the ground, not onboard aricraft, capable of controlling RPA. The laws also require that all managements necessary to operate RPA and pilots safely and efficiently under the structure of the unmanned aircraft system within the scope of the regulations. Each country classifies the RPA as an aircraft less than 25kg. Australia and Germany further break down the RPA at a lower weight. ICAO stipulates all general aviation operations, including commercial operation, in accordance with Annex 6 of the Chicago Convention, and it also applies to RPAs operations. However, passenger transportation using RPAs is excluded. If the operational scope of the RPAs includes the airspace of another country, the special permission of the relevant country shall be required 7 days before the flight date with detail flight plan submitted. In accordance with Federal Aviation Regulation 107 in the United States, a small non-leisure RPA may be operated within line-of-sight of a responsible navigator or observer during the day in the speed range up to 161 km/hr (87 knots) and to the height up to 122 m (400 ft) from surface or water. RPA must yield flight path to other aircraft, and is prohibited to load dangerous materials or to operate more than two RPAs at the same time. In Germany, the regulations on UAS except for leisure and sports provide duty to avoidance of airborne collisions and other provisions related to ground safety and individual privacy. Although commercial UAS of 5 kg or less can be freely operated without approval by relaxing the existing regulatory requirements, all the UAS regardless of the weight must be operated below an altitude of 100 meters with continuous monitoring and pilot control. Australia was the first country to regulate unmanned aircraft in 2001, and its regulations have impacts on the unmanned aircraft laws of ICAO, FAA, and EASA. In order to improve the utiliity of unmanned aircraft which is considered to be low risk, the regulation conditions were relaxed through the revision in 2016 by adding the concept "Excluded RPA". In the case of excluded RPA, it can be operated without special permission even for commercial purpose. Furthermore, disscussions on a new standard manual is being conducted for further flexibility of the current regulations.

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The Consideration of the Region of Interest on $^{99m}Tc$-DMSA Renal Scan in Pediatric Hydronephrosis Patients (수신증을 진단 받은 소아 환자의 DMSA 신장 검사에서 정확한 관심영역 설정에 대한 고찰)

  • NamKoong, Hyuk;Lee, Dong-Hyuk;Oh, Shin-Hyun;Cho, Seok-Won;Park, Hoon-Hee;Kim, Jung-Yul;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.1
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    • pp.27-33
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    • 2012
  • Purpose: Most of diagnosis in the pediatric hydronephrosis patients have been performed $^{99m}Tc$-DMSA renal scan. Then the region of interest (ROI) is set for comparative analysis of uptake ratio in left-right kidney after acquiring the image. But if the equipment set an automatic ROI, the ROI could include expanded renal pelvis due to hydronephrosis and the uptake ratio of left-right kidney will be incorrect result. Therefore this study compared both ROIs including expanded renal pelvis and excluding renal pelvis through experiment using normal kidney phantom and expanded renal pelvis phantom and suggested setting method of improved ROI. In addition, this study have been helped by readout doctor for investigate distinction radiopharmaceutical uptake between renal cortex and remained urine by expanded renal pelvis. Materials and Methods: The both of renal phantoms were filled with water and shacked with $^{99m}TcO_4$ 111 MBq. In order to describe the expanded renal pelvis, the five latex balloon were all filled with 10 mL water and each of balloon was mixed with $^{99m}TcO_4$ 18.5, 37, 55.5, 74, 92.5 MBq. And we made phantom with fixed $^{99m}TcO_4$activity of 37 MBq and mixed water 5, 10, 15, 20, 25 mL in each balloon. The left kidney was fixed its shape and the right kidney was modified like as hydronephrosis kidney by attached the latex balloons. And the acquiring counts were 2 million. After acquisition, we compared the image of ROI with Expanded renal pelvis and the image of ROI without renal pelvis for analyzing difference in the uptake ratio of left-right kidney and for reproducibility, set the ROI 5 times in the same images. Patients were injected $^{99m}Tc$-DMSA 1.5~1.9 MBq/kg and scanned 3 to 4 hours after injection. The each of 3 skillful radio technologists performed the comparing estimation by setting ROI. To determine statistical significance between two data, SPSS (ver. 17) Wilcoxon Signed Ranks Test was used. Results: As a result of renal phantom's experiment, we compared with average of counts Background (BKG) ratios in the setting of ROI including expanded renal pelvis and setting of excluding expanded renal pelvis. Therefore, they can obtain changed counts and changed ratios. Patient also can obtain same results. In addition, the radiopharmaceutical uptake in expanded renal pelvis was come out the remained urine that couldn't descend to ureter by the help of readout doctor. Conclusion: As above results, the case of setting ROI including expanded renal pelvis was more abnormally increasing uptake ratio than the case of setting ROI excluding expanded renal pelvis in analysis the uptake ratio in left-right kidney of hydronephrosis. Because of the work convenience and prompted analysis, the automatic ROI is generally used. But in case of the hydronephrosis study, we should set the manual ROI without expanded renal pelvis for an accurate observation of the uptake ratio of left-right kidney since the radiopharmaceutical uptake in expanded renal pelvis is the remained urine.

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Studies on the Lipid of Aquatic Products (Part 4) On the Flesh Lipid Composition of Cephalopods (수산물의 지질에 관한 연구 (제4보) -두족류의 근육지질성분에 대하여-)

  • HA Bong-Seuk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.1
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    • pp.59-73
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    • 1982
  • Differences of lipids, especially total lipid composition, fatty acid and sterol composition of the flesh lipids between three species of cephalopods were investigated, since available researches concerning lipids in flesh tissues of the cephalopod are very limited. Extracted total lipid from the flesh tissues were fractionated by silicic acid column chromatography into three lipid classes of neutral lipids, glycolipids and phospholipids. The lipid compositions of total lipid and neutral lipids were estimated by the method of thin layer chromatography and TLC-scanner. The sterol compositions of unsaponifiable matters from total lipid were determined by using thin layer chromatography and gas-liquid chromatography. The fatty acid composition of each lipid class was also determined by gas-liquid chromatography. Total lipid contents of flesh tissues from three species of the cephalopods were 0.5 in Octopus vulgare, 0.8 in Octopus variabilis and $0.6\%$ in Loligo beka based on wet weight, the contents of total fatty acid in total lipid were 19.3, 47.8 and $38.4\%$, and the contents of unsaponifiable matters were 10.9, 18.8 and $41.1\%$, respectively. Total lipid was mainly composed of sterols and polar lipid-pigments as major components in each sample and the proportion of sterols and polar lipid-pigments to total lipid ranged from 27.0 to $35.5\%$ and 38.3 to $63.4\%$, respectively. The other lipid components of total lipid, e.g. triglycerides, free fatty acids, and carbohydrate-esterified sterols were determined as a minor components. The major component fatty acid in total lipid was palmitic acid and additionaly it chiefly consisted of the other unsaturated acids such as oleic, linoleic, octadecatetraenoic and eicosapentaenoic acid as major components of the acid. The compositions of sterol in three species of cephalopod were found to contain mainly cholesterol for its proportion to total sterols was 82.4 to $89.1\%$. However the other sterols such as 22-dehydrocholesterol and 24-methylenecholesterol were determined in addition to cholesterol as a minor components. The result of fractional composition of lipid class in total lipid was that total lipid had large .amount of polar lipid and small amount of nonpolar lipid i, e, neutral lipid in each sample, and the contents of phospholipid were higher than that of glycolipid in polar lipid. Neutral lipid was mainly composed of free sterol as major components in each sample and its proportion of free sterols to total neutral lipid was 50.0 to $70.5\%$. The other lipid components of neutral lipid showing similar in quantity, esterified sterols, free fatty acids and triglycerides were determined as a minor components. The major components fatty acid in neutral lipid were palmitic, oleic and hexadecadienoic acid. Palmitic acid was the most abundant and additionaly oleic, linoleic, octadecatetraenoic and myristic acid were the major component fatty acid in glycolipid. But, especially, glycolipid of Loligo beka contained a higher amount of arachidonic acid which also consists of major component in addition to those of acids. Palmitic acid was the most abundant and additionaly, oleic, linoleic and octadecatetraenoic acid were the major component fatty acids in phospholipid.

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Effects of CDP-Choline, Aminoguanidine and Difluoromethylornithine on the ECS-induced Impairment of Active Conditioned Response Retention (백서의 조건회피반응-유지에 대한 경련성 전기충격의 저해작용에 미치는 CDP-Choline, Aminoguanidine, 및 Difluoromethylornithine의 영향에 관한 연구 : 뇌내 Acetylcholine과 Polyamine 함량-변동에 연관하여)

  • Kim, Hyung-Gun;Kim, Chang-Hyun;Choi, Sang-Hyun;Ihm, Suk-Young;Lee, Min-Soo;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.28 no.2
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    • pp.115-128
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    • 1992
  • The training of male wistar rats for active conditioned response (ACR) was performed by one daily training session of 30 consecutive trials for 10 successive days using a two-way shuttle box, and the rats that showed 10 or more ACRs on the last day were treated for further 10 days with electroconvulsive shock (ECS : 50 mA, 0.5 msec; 100 Hz; 1.5 sec) and the following compounds. On the 20th day, all the rats were tested for the ACR rention. The ECS regimens were one ECS per day for 10 days with one day interval $(5{\times}ECS)$, one ECS at 3 hrs (ECS-3h), and one ECS at 24 hrs (ECS-24h), respectively, before the ACR retention test. And CDP-choline (cc: 250 mg/kg), spermine (SM: 10 mg/kg), ${\alpha}-difluoromethylornithine$ (DO: 250 mg/kg), or aminoguanidine (AG: 100 mg/kg) was administered by one daily i.p. injection for 10 days. The ACR number $(13.7{\pm}1.0)$ obtained on the last training day was increased by 37.23% on the 20th day in the control rats. And the ACR increase was significantly suppressed by 5-ECS, ECS-3h, CC, or SM but was little affected by ECS-24h, DO, or AG. However, the 5-ECS induced impairment of ACR retention was significantly suppressed by AG, SM, and CC in the order of potency but was little affected by DFMO. And the ECS-3h induced impairment was moderately worsened by SM or AG. The acetylcholine (ACh) of the rat hypothalamus (HT), hippocampus (HC), and entorhinal cortex (EC) was markedly increased by CC and moderately increased by SM, but little affected by ECS-3h, ECS-24h, DO, or AG. But $5{\times}ECS$ slightly increased the ACh content. The brain putrescine (Pt) content was significantly increased by AG and little affected by CC, SM, or DO. But the $5{\times}ECS$ markedy decreased the brain Pt content, and the decrease was significantly suppressed by CC, SM, or AG. CC induced the marked increases of the spermidine (Sd) and spermine (Sm) contents of all the areas. SM increased the Sd contents of all the areas and the EC-Sm content. DO decreased the brain Sd and Sm contents. And AG increased the HT-Sd content and the Sm contents of all the brain areas. The $5{\times}ECS$ induced decrease of the HC-Sm content was suppressed by CC, SM and AG. These results suggest that the improving effect of aminoguanidine on the $5{\times}ECS$ induced impairment of ACR retention may be ascribed in part to its activity as a diamine oxidase inhibitor.

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THE EFFECTS OF VARIOUS TETRACYCLINE HCL CONCENTRATION TREATED ROOW SURFACES ON PROLIFERATION AND SPREADING OF PERIODONTAL LIGAMENT CELLS (다양한 농도의 테트라사이클린로 처리된 치근면이 치주인대세포의 증식과 전개에 미치는 영향)

  • Jung, Oh-Chul;Sun, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.24 no.3
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    • pp.581-596
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    • 1994
  • This in vitro study was undertaken to obtain optimal tetracycline concentration that aids proliferation and spreading of human periodontal ligament cells, for clinical application in root surfaces of periodontally diseased teeth. Periodontal ligament cells used in this study were obtained from explants of periodontal ligament of 1st premolar teeth which were extracted for the purpose of orthodontic treatment. The cells were cultured in Dulbecco's Modified Eagle Medium(DMEM) supplemented with 100 U/ml penicillin, $100\;{\mu}g/ml$ streptomycin and 10% FBS at $37^{\circ}C$, 100% humidity, 5% $CO_2-95%$ air. Cells were used between the third to 4th passage. After root planing of periodontally extracted teeth, the root slabs were cut with carborundum disk. In the cell proliferation experiment, experimental groups were root planing only group, immersed groups in 25, 50, 75, 100, 150mg/ml aqueous solution of Tetracycline HCl followed by a vigorous rinse in PBS. Human PDL cells at concentration of $1{\times}10^5\;cells/ml$ were seeded in each culture well which contained root slabs and incubated for 6 hours. Then, all of the root slabs were moved into new 24 culture well and incubated 24, 48 and 72 hours. The cell counting was done by inverted phase contrast microscope after trypsinization. The following results were obtained. The cell number was increased in order root planing only group, 25, 150, 50, 75, 100mg/ml of Tetracycline HCl treated group in 24, 48 and 72 hours. The maximal cell number was obtained when the root slabs were immersed in solution with 100mg/ml of Tetracycline HCl. There were statistically significant between the root planing only group and 75, 100 mg/ml of Tetracycline HCl treated group in 24 hours, between the root planing only group and 100mg/ml of Tetracycline HCl treated group in 48 hours, between the root planing only group and 50, 75, 100mg/ml of Tetracycline HCl treated group, between 25 and 100mg/ml of Tetracycline HCl treated group in 72 hours(p<0.05). In the cell spreading experiment, after 30 minutes of incubated, in the root planing only group, the cells were generally round in shape. The cell surface was mostly covered with blebs. The cells started to attach to root surface by cytoplasmic extension in 50, 100mg/ml of Tetracycline HCl treated groups, more numerous cells attached to root surface than root planing only group. Many orifices of dentinal tubule were exposed, cells showed radially spreaded cytoplasm and unspreaded central region of the cell was covered with blebs. After 6 hours of incubation, in the root planing only group, cells showed radially spreaded cytoplasm and were attached flat appearance. In 50, 100mg/ml of Tetracycline HCl treated groups, cellular margin was concaved and cytoplasm showed elongated appearance with polarity. After 24 hours of incubation, in the root planing group, cells showed characteristic polarity. In 50, 100mg/ml of Tetracycline HCl treated groups, cells showed more elongated and spindle - like appearance.

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COMPARISON OF POLYMERIZATION SHRINKAGE AND STRAIN STRESS OF SEVERAL COMPOSITE RESINS USING STRAIN GUAGE (스트레인 게이지를 이용한 수종의 복합레진의 중합수축 및 수축응력의 비교)

  • Kim, Young-Kwang;Yoo, Seung-Hoon;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.3
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    • pp.516-526
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    • 2004
  • Polymerization shrinkage of photoinitiation type composite resin cause several clinical problems. The purpose of this study was to evaluate the shrinkage strain stress, linear polymerization shrinkage, compressive strength and microhardness of recently developed composite resins. The composite resins were divided into four groups according to the contents of matrix and filler type. Group I : $Denfil^{TM}$(Vericom, Korea) with conventional matrix, Group II : $Charmfil^{(R)}$(Dentkist, Korea) with microfiller and nanofller mixture, Group III : $Filtek^{TM}$ Z250(3M-ESPE, USA) TEGDMA replaced by UDMA and Bis-EMA(6) in the matrix, and Group IV : $Filtek^{TM}$ Supreme(3M-ESPE, USA) using pure nanofiller. Preparation of acrylic molds were followed by filling and curing with light gun. Strain gauges were attached to each sample and the leads were connected to a strainmeter. With strainmeter shrinkage strain stress and linear polymerization shrinkage was measured for 10 minutes. The data detected at 1 minute and 10 minutes were analysed statistically with ONE-way ANOVA test. To evaluate the mechanical properties of tested materials, compressive hardness test and microhardness test were also rendered. The results can be summarized as follows : 1. Filling materials in acrylic molds showed initial temporary expansion in the early phase of polymerization. This was followed by contraction with the rapid increase in strain stress during the first 1 minute and gradually decreased during post-gel shrinkage phase. After 1 minute, there's no statistical differences of strain stress between groups. The highest strain stress was found in group IV and followed by group III, I, II at 10 minutes-measurement(p>.05). In regression analysis of strain stress, group III showed minimal inclination and followed by group II, I, IV during 1 minute. 2. In linear polymerization shrinkage test, the composite resins in every group showed initial increase of shrinkage velocity during the first 1 minute, followed by gradually decrease of shrinkage velocity. After 1 minute, group IV and group III showed statistical difference(p<.05). After 10 minutes, there were statistical differences between group IV and group I, III(p<.05) and between group II and group III(p<.05). In regression analysis of linear polymerization shrinkage, group II showed minimal inclination and followed by group IV, III, I during 1 minute. 3. In compressive strength test, group III showed the highest strength and followed by group II, IV, I. There were statistical differences between group III and group IV, I(p<.05). 4. In microhardness test, upper surfaces showed higher value than lower surfaces in every group(p<.05).

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A Comparative Study on Awareness of Middle School Students, School Parents, and Human Resources Directors in Industrial Institutions about Admission into Specialized High Schools and Career after Graduating from Specialized High Schools (특성화고 진학 및 졸업 후 진로에 대한 중학생, 학부모, 산업체 인사 담당자의 인식 비교 연구)

  • Lee, Byung-Wook;Ahn, Jae-Yeong;Lee, Chan-Joo;Lee, Sang-Hyun
    • 대한공업교육학회지
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    • v.38 no.2
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    • pp.48-67
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    • 2013
  • This study tried to suggest implications about operation direction of specialized high schools (SHS) by researching awareness of middle school students (MSS), school parents (SP), human resources directors in industrial institutions (HRDII) who will be the main users of SHS education, about entering SHS and career after graduating from SHS. Seniors of middle school, SP and HRDII in Asan, Chungnam were the subject of this survey research. The summary of the result of this study is as follow: First, MSS and SP usually hoped to enter general high schools rather than vocational education schools such as SHS, meister high schools, and MSS considered school records and SP considered aptitude and talent for the factors to choose high school. Second, MSS, SP, and HRDII recognized purposes of SHS as improvement of talent and aptitude, and getting a job. As for positive images of SHS, they recognized it as applying talent and aptitude to life early, getting good jobs easily, fast independence after graduation, and learning excellent technologies, and as for negative images of SHS, they recognized it as social prejudices and discrimination, students with bad school records enter them, disadvantages about promotion and wages, and being unfavorable for entering universities. They also recognized education of SHS as being effective for improvement of basic and executive ability and key competency, development of creative human resources, and improvement of right personality and courteous manners. Third, many MSS and SP showed intention to enter SHS if it is established in Asan. They wished to enter SHS because they would like to apply their aptitude and talent to life early, learn excellent skill, and hope for early employment, on the other hand, they did not wish to enter SHS because it was not suited for their aptitude and talent, awareness about SHS is low, it is unfavorable to enter universities, and there were social prejudices and discrimination. They also similarly hoped for getting jobs and entering universities after graduating from SHS. And the reason they wanted to get a job was usually because they want to be successful by advancing into society early, or because it is still hard to get a job even after graduate from the university, on the other hand, the reason they want to enter university is because is usually in-depth education about major and social discrimination about level of education. The ability to perform duties forms the greatest part of the employment standard that MSS, SP, and HRDII aware. MSS and SP usually hoped for industrial, home economics and housework and commercial majors in SHS, and considered aptitude and talent, the promising future, and being favorable for employment for choosing major. The reason HRDII hire SHS student was to develop student into talent of industrial institution, ability of student, and need for manpower with high school graduation level, and there were also partial answer that they can hire SHS student if they have ability to perform duties. The proposals about operation direction of SHS according to the results above are as follow: SHS should diversify major and curriculum to meet various requirements of student and parents, establish SHS admission system based on career guidance, and improve student's ability to perform duties by establishing work-based learning. The Government should organize work-to-school policy to enable practical career development of students from SHS, and promote relevant policy to reinforcing SHS education rather than quantitative evaluation such as employment rate, and cooperative support from each government departments is required to make manpower with skill related to SHS to get proper evaluation and treatment.