• Korean Chemical Engineering Research
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• 제55권3호
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• pp.363-368
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• 2017

메탄올자화균이란 일탄소 화합물인 메탄올을 주탄소원 및 에너지원으로 이용할 수 있는 미생물을 말한다. Methylobacterium extorquens AM1은 serine cycle을 탄소대사경로로 이용하는 메탄올자화균 중에서도 가장 많이 연구가 진행된 균주이다. M. extorquens AM1의 poly 3-hydroxybutyrate (PHB) cycle은 EMCP (ethylmalonyl-CoA pathway), glyoxylate regeneration cycle, TCA cycle과 연결되어 있으며 EMCP 유래 유기산 또는 TCA 유기산을 생산하기 위해서는 PHB cycle로 흐르는 carbon flux의 차단이 필요하다. 이를 위해서 PHB 합성과 acetyl-CoA flux의 조절유전자로 알려져 있는 PhaR 유전자를 markerless gene deletion 방법을 이용해서 M. extorquens AM1에서 knockout했다. 결과적으로, knockout 균주인 ${\Delta}phaR$에서 야생종 대비 확연히 PHB granule이 줄어든 것이 확인되었다. Lag phase가 약 12 h 늦어졌지만, ${\Delta}phaR$은 야생종과 비슷한 세포성장과 메탄올소비 경향을 보임을 확인하였다.

• Safety and Health at Work
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• 제10권2호
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• pp.229-236
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• 2019

Background: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. Methods: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. Results: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from $4.1{\times}10^{10}$ (Ultem filament) to $2.2{\times}10^{11}$ [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (${\mu}g/min$) ranged from $1.9{\times}10^4$ (acrylonitrile butadiene styrene and polycarbonate) to $9.4{\times}10^4$ (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open ($2.3{\times}10^{10}number/min$) than when the lid was closed ($1.5-5.5{\times}10^9number/min$); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. Conclusion: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

• 구강회복응용과학지
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• 제37권1호
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• pp.1-15
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• 2021

치과용 재료의 적층가공제작은 기존 제작방식에 비해 복잡한 형태까지 제작할 수 있으며 절삭가공에 비해서도 기구나 재료의 소모가 적어 지속가능성이 장점으로 대두되고 있다. 적층가공 제작은 7가지 방식으로 분류할 수 있는데, 폴리머는 적층가공에 가장 적합한 재료로 용기중합방식으로 제작하며 기존 자가중합방식에 비해 높은 물성과 적합도를 가져 상용화에 더 적합하지만 상대적으로 낮은 강도로 인해 임시수복물로 주로 이용된다. 금속은 PBF (powder bed fusion) 방식을 주로 이용하며 주조방식에 비해 파괴인성과 밀도가 높지만 잔류응력이 높아 이를 제거하기 위한 후처리방식에 대한 연구가 필요하다. 세라믹은 분말과 레진폴리머를 혼합한 재료를 용기중합하는 방식이 일반적이다. 제작 후 폴리머제거나 소결과 같은 후처리 과정이 복잡하다. 상용화되려면 세라믹 적층가공에 의한 결과물의 낮은 강도와 체적정확성이 개선되어야 한다. 적층가공은 어떤 재료이건 공정조건에 따라 물성과 표면환경이 달라지므로 가장 적합한 공정조건을 찾기 위한 연구가 더 많이 필요하다고 사료된다.

• 대한한의학회지
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• 제30권2호
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• pp.104-116
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• 2009

Objectives: This experimental study was designed to show the relationship between kidney qi deficiency and hypoadrenia. A comparative study between Sa-am and local area acupuncture stimulation was conducted. The test results help to show the relationship between kidney qi deficiency and hypoadrenia as well as the recuperation of the patient with the use of VAS, ROM, Sch ber test, ODI and salivary cortisol testing. Methods: 1. Twenty-four adults with chronic low back pain were recruited. Once selected the test population was divided into two different groups. One group was treated only with the use of local area acupuncture and the other with Sa-am acupuncture. 2. At the completion of each acupuncture treatment both groups underwent a VAS, ROM, ODI, $Sch{\ddot{o}}ber$ Test and salivary cortisol test. Results: 1. Both the Sa-am acupuncture group and the local area acupuncture group had statistical significance in VAS decrease and flection ROM increase. 2. Only the Sa-am acupuncture group had statistical significance in extension ROM increase. Only the local area acupuncture group had statistical significance in both lateral flection ROM increase and ODI test. 3. There was statistical significance of correlation between morning salivary cortisol test and adrenal fatigue questionnaire. Conclusions: Both local area acupuncture as well as Sa-am acupuncture treatments were effective for treating lower back pain caused by kidney qi deficiency. In addition, each patients recuperation level can be verified with the results seen from the salivary cortisol test results. The cortisol results suggest a similarity between kidney qi deficiency and hypoadrenia.

• 방송공학회논문지
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• 제17권6호
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• pp.990-1003
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• 2012

본 논문에서는 디지털라디오와 관련하여 동일계열 기술인 DRM과 DRM+ 전송방식을 기반으로 AM과 FM의 디지털방송 추진의 가능성과 필요성을 제시한다. 주파수 활용에서 IN-BAND와 OUT-OF-BAND 양쪽 모두 이용이 가능한 DRM+의 특징을 이용하여 FM밴드와 인접한 LOW-VHF 대역 TV채널 5번과 6번 주파수를 OUT-OF-BAND방식으로 디지털라디오방송을 추진할 때 기존 FM방송 신호와 충돌과 혼신이 없고, 새로운 라디오영역으로 확보 가능하며, 우수한 신호전달 능력이 있는지 확인하고자 하였다. 특히 IN-BAND방식 Hybrid 모드에서 SFN을 이용한 다수의 송신기 사용이 어려운 문제점을 언급하였다. 그와 반대로 DRM+에 의한 OUT-OF-BAND 방식은 다수의 송신기 배치가 가능하며, 기존 FM송신기 및 안테나와 콤바인이 쉽고, 사업자별로 출력지정과 권역설정이 자유로우며, AM/FM 통합 디지털라디오 제작과 보급에 유리하여 디지털라디오 추진에 적합한 방안이 될 수 있음을 제안하였다.

• 동의생리병리학회지
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• 제26권4호
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• pp.432-436
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• 2012

Among a number of factors related to the effect of acupuncture and moxibustion treatment, prescriptions do important work. Traditional eastern doctors also placed emphasis on prescriptions of acupuncture and moxibustion, and a lot of experiences have been accumulated. The method forms prescriptions of Sa-am acupuncture therapy pivots on five transport points. Studies show prescriptions are made on the basis of the theory of 'Wang Xiang Xiu Qiu Si'(旺相休囚死) used engendering and restraining of five phases, and it is considered the principle of transformed prescriptions through this theory. Because there is still no study analyzing prescriptions of Sa-am acupuncture by existing principles, we report opinion about Combination principle of points in them. 1. We studied history of acupuncture and moxibustion, development and kinds of points' Combination principle. 2. Around Combination principles of points in Classic of Difficult Issues and Internal Classic, we analyzed and compared between Combination principles of points in Sa-am acupuncture therapy and them in Korea and overall acupuncture methods. 1. There were many Combination principles of acupunture point combination in Classic of Difficult Issues, Internal Classic and Korea acupuncture methods. For example, Point combination of the same meridian, Point combination of the different meridian, Exterior-Interior point combination, Point combination of the same name meridian, Point combination of the multiple meridian, Point combination of Adjacent and Distant points, Left-Right point combination, Anterior-Posterior point combination, Superior-Inferior point combination, Brook point and Stream point combination, Triple energizer point combination, Eight meeting point combination, Five transport point combination, Source-Connecting point combination, Alram point and Transport point combination, Mother-Sun meridian combination, Empirical point combination, Important point combination, Point combination according to syndrome. 2. Existing Combination principles of points in prescriptions of Sa-am acupuncture therapy included every rule. 3. They could be evidences that prescriptions of Sa-am acupuncture therapy are forms inheriting and developing acupuncture and moxibustion treatments.

• 한국주조공학회지
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• 제18권4호
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• pp.383-388
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• 1998

Effects of $CaCN_2$ addition on the grain refinement in the AM60 magnesium ingots were investigated. The effects of the $CaCN_2$ are estimated with different inoculation temperatures, inoculation contents, and holding time to find out the optimum condition. AM60 alloy was melted in the low carbon steel crucible by cylindrical electric furnace under an argon atmosphere. The melting and casting apparatus is specially designed for magnesium alloys. The grain size of AM60 magnesium alloy decreased significantly with an increase in $CaCN_2$ content and, at 0.8 wt% $CaCN_2$ or more, grain size becomes constant at about $85 {\mu}m$. The optimum condition was obtained in the 0.8 wt% $CaCN_2$ for holding molten metal of 30 min. at the temperature of $710^{\circ}C$. The tensile properties of AM60 magnesium alloys were improved due to grain refinement by addition of $CaCN_2$. In the optimum condition, the yield strength, tensile strength and elongation were ${\sigma}_{0.2}=107 MPa$, ${\sigma}_{T.S}=234 MPa$ and e=14.2%. The variation of stress with strain obeyed the relationship of the ${\sigma}=K{\varepsilon}^n$. The strain-hardening exponent, n and strength coefficient, K obtained in the 0.8 wt% $CaCN_2$ added AM 60 magnesium alloy were n=0.21 and K=390 MPa.

• The Korean Journal of Physiology and Pharmacology
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• 제28권3호
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• pp.219-227
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• 2024

Bladder cancer remains the 10th most common cancer worldwide. In recent years, metformin has been found to have potential anti-bladder cancer activity while high concentration of IC₅₀ at millimolar level is needed, which could not be reached by regular oral administration route. Thus, higher efficient agent is urgently demanded for clinically treating bladder cancer. Here, by conjugating artesunate to metformin, a novel artesunate-metformin dimer triazine derivative AM2 was designed and synthesized. The inhibitory effect of AM2 on bladder cancer cell line T24 and the mechanism underlying was determined. Anti-tumor activity of AM2 was assessed by MTT, cloning formation and wound healing assays. Decreasing effect of AM2 on lipogenesis was determined by oil red O staining. The protein expressions of Clusterin, SREBP1 and FASN in T24 cells were evaluated by Western blotting. The results show that AM2 significantly inhibited cell proliferation and migration at micromolar level, much higher than parental metformin. AM2 reduced lipogenesis and down-regulated the expressions of Clusterin, SREBP1 and FASN. These results suggest that AM2 inhibits the growth of bladder cancer cells T24 by inhibiting cellular lipogenesis associated with the Clusterin/SREBP1/FASN signaling pathway.

• 건축역사연구
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• 제33권4호
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• pp.43-50
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• 2024

In-beop-dang (因法堂) is a building type that can confirm the complex space composition of the hermitage in the late Joseon Period, which is designed to accommodate various functions such as Buddhist priesthood, living spaces, and auditoriums. These facts have been confirmed mainly through plan analysis in many previous researches. However, such a plan composition has the potential to lead to more in-depth research when dealt with consideration of the Korean traditional wooden structure. In particular, the composition of upper structure in In-beop-dang with Toi-maru in front of the On-dol room can be considered from the perspective of structural response to wooden architecture in the Joseon period after the introduction of Toi-maru. Based on the achievements of these prior studies, this paper was conducted to examine the compositional characteristics, including the upper structure of the Wha-jang-am (華藏庵) In-beop-dang. In order to examine the universal aspects of structural type changes to cope with the complex spatial composition of the In-beop-dang, the cases of an in-mountain hermitage of Kim Nyong-sa(金龍寺) Temple, Geum-seon-dae (金仙臺), Yang-jin-am (養眞庵), and Dae-sung-am (大成庵).

• 한국초지조사료학회지
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• 제21권4호
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• pp.191-202
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• 2001

Experiments were conducted on established grassland sward at Gongiam, Kwangju, and Kyung-gi in Korea from 1995 to 1997. The influence of mineral-N fertilizer or animal manure(AW) on herbage dry matter(DM) yield, N yield, the recovery of AM-N, and soil N and organic matter(0M) content in the mixed sward('potomac' orchardgrass, 'fawn' tall fescue, and 'kenblue' Kentuky bluegrass) was investigated. The treatments were replicated three times in a split plot block design. AM(the main plots) was applied at 200kg N ha ' year ' on each plot. The types of AM were cattle feedlot manure(CFM), pig manure fermented with sawdust(PMFS) and Korea native cattle slurry(KNCS). Three levels of mineral-N fertilizer, as urea, ranging from 0 to 200kg N $ha^{-1}\;year^{-1}$ in 100kg increments, were superimposed on each plot. The fertilizers and AM were applied in two equal dressings(the end of March and middle of November). AM and mineral fertilizer had significant effects(p<0.05) on herbage DM and N yields. Herbage yields in KNCS were higher than those in CFM and PMFS(p