아세트酸-물 溶媒系에 의한 木材의 有機酸 蒸解效果

李宣鎬,趙炳默 江源大學校 林科大學 森林科學硏究所 1993 Journal of Forest Science Vol.9 No.-

무공해 대체 펄프화법 개발의 일환으로 비교적 최근에 많은 연구가 이루어지고 있는 아세트산-물 용매 중해법을 이용하여 현사시나무와 소나무를 펄프화 하였다. 펄프 특성의 변화에서 현사시나무는 거의 모든 아세트산 중해조건에서 우수한 펄프화 경향을 보였지만 소나무는 저온에서 중해가 거의 일어나지 않았다. 현사시나무의 최적 중해조건은 중해농도 95%, 중해온도 185℃, 중해시간 0.5hr이었다. 구성당 성분의 거동은 현사시나무와 소나무에서 glucose만이 소량 감소하는 반면 그외의 당성분들은 다량 용출되었다. 폐액중의 용출 아세트산 리그닌에 대한 기초적인 성질을 살펴본 결과 현사시나무의 아세트산 리그닌의 원소조성은 C가 63.88%, H가 5.45%, O가 30.67%이며 C의 formular는 였고 소나무의 아세트산 리그닌의 조성은 C가 61.85%, H가 6.14%, O가 32.01%이며 C의 formular는 이었으며 두 수종의 아세트산 리그닌 중합 평균분자량은 현사시나무가 731이며 소나무는 725였다. There are a lot of serious problums associated with conventional pulping processes, such as kraft and sulfite. In order to tackle these difficulties, organic acid pulping of Populus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. have been investigated as on alternative method. The acetic acid cooking of Populus tomentiglandulosa T. Lee achieved good delignification with pulp yields of 55-65% under almost all cooking conditions. In the acetic acid cooking of Pinus densiflora S. et Z., it was not cooked at a low temperature. The strength properties of the acetic acid pulps from Pinus tomentiglandulosa T. Lee showed the optimum with 95% acetic acid concentration at 185℃ maximum cooking temperature for 0.5hr cooking time. The strength properties of the acetic acid pulps from Pinus densiflora S. et Z. displayed excellent tear strength in comparison with those of the other softwoods. In the process of acetic acid cooking, glucose has been removed a little, but other sugars have been eliminated. The elemental compositions and formulas of acetosolv lignins from Populus tomentiglandulosa T. Lee were 63.88% carbon, 5.45% hydrogen and 30.67% oxygen and . The elemental compositions and formulas of acetosolv lignins from Pinus densiflora S. et Z. were 61.85% carbon, 6.14% hydrogen and 32.01% oxygen and . The Wt.av.MWT's of the acetosolv lignins from Pinus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. were 731 and 725.

Variations in Soil-to Red Pepper Transfer Factors of Radionuclides with Time of Their Application and Fruit Harvest

Choi,Yong-Ho,Lee,Won-Yun,Lim,Kwang-Muk,Park,Doo-Won,Lee,Myung-Ho,Lee,Chang-Woo,Lee,Hyun-Duk,Lee,Jung-Ho 대한방사선 방어학회 1997 방사선방어학회지 Vol.22 No.3

고추의 이식 2일전 및 이식후 세 차례에 걸쳐 54Mn, 60Co, 85Sr , 137Cs의 혼합용액을 온실내 재배상자의 토양에 처리하고 고추의 청과와 적과에 대한 전이계수(㎡/㎏-dry)를 조사하였다. 전이계수는 핵종, 처리시기 및 수확시기에 따라 20∼100배 정도의 변이를 보였다. 핵종간에 전이계수는 대체로 85Sr>54Mn> 60C> 137Cs의 순이었으나 처리에서 수확까지의 기간이 짧을 경우 54Mn와 60Co 전이계수가 85Sr보다 높았다. 85Sr와 137Cs 전이계수는 가장 늦은 처리에서 그 전처리에 비해 수확시기에 따라 3∼20배 정도 감소하였다. 54Mn와 60Co 전이계수는 이식후 처리시기에 따른 변이가 비교적 적었다. 이식전 토양과의 혼합처리시 전이계수는 이식 2일후 토양 표면 처리에 비해 54Mn, 60Co , 85Sr 의 경우 최고 3∼9배 정도 높았으나 137Cs 의 경우 차이가 없었다. 본 연구 결과는 고추의 재배기간중 사고발생시 고추 열매내 방사성 핵종의 뿌리흡수 농도를 예측하고 고추의 수확 및 이용대책을 수립하는 데 활용될 수 있다. A mixed solution of 54Mn, 60Co, 85Sr and 137Cs was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors (㎡/㎏-dry) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about 20∼100. They decreased mostly in the order of 85Sr>54Mn> 60C> 137Cs while 54Mn and 60Co was higher than 85Sr when time lapse between application and harvest was short. Transfer factors of 85Sr and 137Cs at the last applocation were lower than those at the previous one by factors of 3∼20 depending on harvest time. Variations in 54Mn and 60Co transfer factors with application time after transplanting were comparatively low. Transfer factors of 54Mn, 60Co and 85Sr mixed with topsoil before transplanting were up to 3∼9 times higher than those for the application onto soil surface 2 days after transplanting while there was no difference in 137Cs. The present results can be referred to in estimating root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper.

Variations in Soil-to-Red Pepper Transfer Factors of Radionuclides with Time of Their Application and Fruit Harvest

Yong-Ho Choi,Won-Yun Lee,Kwang-Muk Lim,Doo-Won Park,Myung-Ho Lee,Chang-Woo Lee,Hyun-Duk Lee,Jeong -Ho Lee 대한방사선방어학회 1997 방사선방어학회지 Vol.22 No.3

Highly Flexible, Proton-Conductive Silicate Glass Electrolytes for Medium-Temperature/Low-Humidity Proton Exchange Membrane Fuel Cells

Lee, Hyeon-Ji,Kim, Jung-Hwan,Won, Ji-Hye,Lim, Jun-Muk,Hong, Young Taik,Lee, Sang-Young American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.11

<P>We demonstrate highly flexible, proton-conductive silicate glass electrolytes integrated with polyimide (PI) nonwoven fabrics (referred to as “b-SS glass electrolytes”) for potential use in medium-temperature/low-humidity proton exchange membrane fuel cells (PEMFCs). The b-SS glass electrolytes are fabricated via in situ sol–gel synthesis of 3-trihydroxysilyl-1-propanesulfonic acid (THPSA)/3-glycidyloxypropyl trimethoxysilane (GPTMS) mixtures inside PI nonwoven substrates that serve as a porous reinforcing framework. Owing to this structural uniqueness, the b-SS glass electrolytes provide noticeable improvements in mechanical bendability and membrane thickness, in comparison to typical bulk silicate glass electrolytes that are thick and easily fragile. Another salient feature of the b-SS glass electrolytes is the excellent proton conductivity at harsh measurement conditions of medium temperature/low humidity, which is highly important for PEMFC-powered electric vehicle applications. This beneficial performance is attributed to the presence of a highly interconnected, proton-conductive (THPSA/GPTMS-based) silicate glass matrix in the PI reinforcing framework. Notably, the b-SS glass electrolyte synthesized from THPSA/GPTMS = 9/1 (mol/mol) exhibits a higher proton conductivity than water-swollen sulfonated polymer electrolyte membranes (here, sulfonated poly(arylene ether sulfone) and Nafion are chosen as control samples). This intriguing behavior in the proton conductivity of the b-SS glass electrolytes is discussed in great detail by considering its structural novelty and Grotthuss mechanism-driven proton migration that is strongly affected by ion exchange capacity (IEC) values and also state of water.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-11/am400836h/production/images/medium/am-2013-00836h_0010.gif'></P>

The Impact of Environmental Pollutants on Barrier Dysfunction in Respiratory Disease

Lee Pureun-Haneul,Park Shinhee,Lee Yun-Gi,Choi Seon-Muk,An Min-Hyeok,Jang An-Soo 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.6

Respiratory epithelial cells form a selective barrier between the outside environment and underlying tissues. Epithelial cells are polarized and form specialized cell-cell junctions, known as the apical junctional complex (AJC). Assembly and disassembly of the AJC regulates epithelial morphogenesis and remodeling processes. The AJC consists of tight and adherens junctions, functions as a barrier and boundary, and plays a role in signal transduction. Endothelial junction proteins play important roles in tissue integrity and vascular permeability, leukocyte extravasation, and angiogenesis. Air pollutants such as particulate matter, ozone, and biologic contaminants penetrate deep into the airways, reaching the bronchioles and alveoli before entering the bloodstream to trigger airway inflammation. Pollutants accumulating in the lungs exacerbate the symptoms of respiratory diseases, including asthma and chronic obstructive lung disease. Biological contaminants include bacteria, viruses, animal dander and cat saliva, house dust mites, cockroaches, and pollen. Allergic inflammation develops in tissues such as the lung and skin with large epithelial surface areas exposed to the environment. Barrier dysfunction in the lung allows allergens and environmental pollutants to activate the epithelium and produce cytokines that promote the induction and development of immune responses. In this article, we review the impact of environmental pollutants on the cell barrier in respiratory diseases.

Aquitalea denitrificans sp. nov., isolated from a Korean wetland.

Lee, Chang-Muk,Weon, Hang-Yeon,Kim, Yoo-Jeong,Son, Jung-A,Yoon, Sang-Hong,Koo, Bon-Sung,Kwon, Soon-Wo Society for General Microbiology 2009 International journal of systematic and evolutiona Vol.59 No.5

<P>A novel bacterium, designated strain 5YN1-3(T), was isolated from wetland peat collected from Yongneup, Korea. The bacterium was facultatively anaerobic, Gram-negative, yellow-coloured, rod-shaped, mesophilic and motile with one polar flagellum. The strain grew optimally at 30 degrees C, at pH 6.0-9.0 and with 0-1 % NaCl (w/v). 16S rRNA gene sequence analysis showed the highest similarity to the sequence from Aquitalea magnusonii TRO-001DR8(T), with 98.7 % sequence similarity. However, strain 5YN1-3(T) showed DNA-DNA relatedness of 43 % (40 % in a reciprocal experiment) with A. magnusonii LMG 23054(T). The strain contained summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c) and C(16 : 0) as major cellular fatty acids. On the basis of DNA-DNA relatedness and physiological and biochemical characterization, strain 5YN1-3(T) should be assigned to a novel species of the genus Aquitalea, for which the name Aquitalea denitrificans sp. nov. is proposed. The type strain is 5YN1-3(T) (=KACC 12729(T) =DSM 21300(T)).</P>

Erratum: Authorship & Funding Acknowledgment Correction

Lee, Hyeon Kyeong,Lee, Young Seung,Jung, Su Jin,Kang, Min Sook,Hwang, Yu Jin,Yoo, Sun Mi,Cha, Yeon Soo,Cho, Soo Muk The Korean Nutrition Society 2019 Journal of Nutrition and Health Vol.52 No.2

Effect of wild ginseng on scopolamine-induced acetylcholine depletion in the rat hippocampus.

Lee, Bombi,Park, Jongbong,Kwon, Sunoh,Park, Moo-Won,Oh, Sang-Muk,Yeom, Mi-Jung,Shim, Insop,Lee, Hye-Jung,Hahm, Dae-Hyun Pharmaceutical Society of Great Britain 2010 Journal of pharmacy and pharmacology Vol.62 No.2

<P>Objectives The ameliorating effects of wild ginseng on learning and memory deficits were investigated in rats. Methods Rats were treated daily with wild ginseng or cultivated ginseng for 7 days at 30 min before scopolamine injection (2 mg/kg, i.p.). After inducing cognitive impairment by the administration of scopolamine, behavioural assessment using the Morris water maze was performed. Changes in cholinergic system reactivity were also examined by measuring the immunoreactive neurons of choline acetyltransferase and the reactivity of acetylcholinesterase in the hippocampus. Key findings Scopolamine injection induced impaired performance in the water maze test and severe cell losses in hippocampal cholinergic neurons, as indicated by decreased choline acetyltransferase immunoreactivity and increased acetylcholinesterase reactivity. Daily administration of wild ginseng produced a significant improvement in the escape latency for finding the platform in the Morris water maze and reduced the loss of cholinergic immunoreactivity in the hippocampus. The reduced expression of brain-derived neurotrophic factor mRNA due to the scopolamine injection was recovered to normal levels by the administration of wild ginseng. Conclusions Wild ginseng demonstrates a significant neuroprotective effect against scopolamine-induced neuronal and cognitive impairment.</P>

DNA Computing the Hamiltonian Path Problem

Lee, Chang-Muk,Kim, Sung Whan,Kim, Sam Myo,Sohn, Uik Korean Society of Molecular Biology 1999 Molecules and cells Vol.9 No.5

Characteristics of oxygenated PAHs in PM 10 at Seoul, Korea

Lee, Hyun Hee,Choi, Na Rae,Lim, Hyung Bae,Yi, Seung Muk,Kim, Yong Pyo,Lee, Ji Yi Elsevier 2018 Atmospheric pollution research Vol.9 No.1