Polyethylene glycol (PEG) 처리에 의한 국내산 소경재의 치수안정화에 관한 연구 Ⅱ : 환경재와 산공재의 비교 Comparison of Ring-Porous Wood and Diffuse-Porous Wood

권구중,권성민,김남훈 한국목재공학회 2003 목재공학 Vol.31 No.4

본 연구에서는 국내산 소경재의 보다 효율적인 이용을 위하여 PEG처리한 활엽수재의 환공재 4수종(신갈나무, 굴참나무, 물푸레나무, 오동나무)과 산공재 4수종(산벚나무, 물박달나무, 층층나무, 은사시나무)에 대한 치수안정성을 평가하였다. 수축률은 공시수종 모두 PEG처리에 의해 감소하는 효과가 있었고, 산공재가 환공재보다 낮았다. 중량증가율은 PEG농도의 증가에 따라 증가되었고, 산공재가 환공재보다 다소 높은 증가율을 보여주었다. 벌킹효과는 PEG농도의 증가에 따라 증가하였지만, 분자량이 클수록 감소하였고, 산공재가 환공재보다 벌킹효과가 높게 나타났다. 결론적으로, 산공재가 환공재보다 높은 치수안정성을 보여주었다. 따라서 PEG처리재의 치수안정효과는 목재의 구조(도관의 분포상태 및 타이로시스 존재유무)와 밀도에 크게 영향받는 것으로 생각되었다. This study was carried out to investigate the dimensional stability of wood treated with PEG for better utilization of domestic small-diameter logs. Four species of ring-porous wood(Quercus mongolica F_(ISCH), Quercus variabilis B-(LUME), Fraxinus rbynchopbhlla H_(ANCE), Paulownia coreana U_(YEKI),) and fore species of diffuse-porous wood(Prunus sargentii R-(EHDER), Betjal davurica P_(ALL), Populus tomentiglandulosa T. L_(EE), cornus controversa H_(EMSLEY)) were used for this experiment. The shrinkage of wood decreased with increasing the concentration of PEG. The shrinkage of diffuse- porous woods was lower than that of ring-porous woods. The weight gain increased in proportional to the PEG concentration. Diffuse-porous woods showed a little higher weight gain than ring-porous woods. Bulking effect also increased with increasing the PEG concentration, but was in inverse proportional to the molecular weight of PEG. Diffuse-porous woods showed higher bulking effect than ring-porous woods. Consequently, diffuse-porous woods showed better dimensional stability than ring porous woods. It was considered that dimensional stability was affected by characteristics of wood such as vessel and tylosis, and density.

한국산 물푸레나무屬 주요 수종의 해부학적 특성

황원중,권구중,박완근,배영수,김남훈 한국목재공학회 2002 목재공학 Vol.30 No.2

물푸레나무속의 물푸레나무, 들메나무 및 쇠물푸레의 해부학적 특성을 광학현미경법과 화상분석법에 의해 조사하였다. 공시 수종간에 연륜 경계의 명확성을 비롯한 도관 요소의 직경, 축방향유조직의 배열상태, 구성세포의 비율에서 차이가 있었다. 구성요소의 방사방향 변이에 있어서, 목섬유 길이, 도관 요소 직경 및 길이는 수심 부위에서 작고 약 10∼15 연륜까지 증가한 후 안정되었다. 결론적으로 본 연구 결과는 물푸레나무속 세 수종의 식별자료 및 성숙재와 미성숙재를 구분하는 재질 지표치로 이용될 수 있을 것으로 생각된다. Anatomical characteristics of Mulpurenamu (Korean ash, Fraxinus rhynchophylla), Deulmaenamu (Manshurican ash, Fraxinus mandshurica) and Sheamulpure (Sieboldiana ash, Fraxinus sieboldiana) grown in Korea were examined by an optical microscopy and an image analysis. Some characteristics such as boundary of annual rings, shape and size of vessel elements, arrangement of axial parenchyma cells in cross section, and cell volumetric composition showed significant differences between the sample species. In radial variation of elements, fiber length and vessel size increased from the pith for about 10 to 15 years and then reached a more or less constant. The results of this study can be used for identification of wood and indices of wood quality in Fraxinus spp.

한국산 물푸레나무屬 주요 수종의 물리 및 역학적 특성

황원중,권구중,김남훈 한국목재공학회 2002 목재공학 Vol.30 No.2

물푸레나무속 주요 수종의 합리적 이용을 위한 기초 자료를 얻기 위해, 물리 및 역학적 특성을 조사하였다. 물푸레나무와 쇠물푸레의 생재함수율은 변 ·심재간 차이가 없었으나, 들메나무 심재분의 생재함수율은 변재부보다 다소 높았다. 들메나무의 생재밀도와 전건밀도는 다른 두 수종에 비해 낮게 나타났고, 쇠물푸레 변재부의 수축 ·팽윤율은 물푸레나무보다 다소 높은 값을 보여주었다. 쇠물푸레의 종압축강도와 종압축탄성계수는 다른 두 수종보다 다소 낮았으며 쇠물푸레 방사 접선단면의 전단강도는 다른 두 수종보다 높게 나타났고, 세 수종 모두 방사단면 전단강도가 접선단면보다 높았다. 세 수종 모두 우수한 휨 특성을 나타냈다. 물푸레나무와 들메나무간에 있어서 충격휨흡수에너지는 유의적인 차이가 없었다. Physical and mechanical properties of major Korean ash species were examined. For Fraxinus rhynchophylla and Fraxinux sieboldiana, green moisture content of sapwood was almost the same value as heartwood. Heartwood of Fraxinus mandshurica, however, had slightly higher moisture content than sapwood. Green and oven dry densities of F. mandshurica were lower than those of F. rhynchophylla and F. sieboldiana. Swelling and shrinkage of sapwood in F. sieboldiana showed somewhat higher valve than those of F. rhynchophylla. Longitudinal compressive strength and modulus of elasticity in F. sieboldiana were lower values than those in the other species. Shearing strength in radial section was higher than that in tangential section of all samples. It could be noted that shearing strength of F. sieboldiana demonstrated higher valve than that of the other species. Three species had excellent bending properties in MOR and MOE. Impact bending absorbed energy for F. rhynchophylla and F. mandshurica did not show any significant differences.

산불 피해 소나무재의 해부 및 물리학적 특성

황원중,권구중,김남훈 한국목재공학회 2003 목재공학 Vol.31 No.4

본 연구에서는 산불 피해를 입은 소나무재의 유효 활용을 위한 기초자료를 얻고자 해부 및 물리학적 특성을 조사하였다. 산불 피해제의 수지구, 에피델리얼세포와 방사유세포내에는 건전재와 달리 과립모양의 물질이 많이 존재하였으며, 그 외의 목부 조직구조는 정상재와 거의 차이가 없었다. 건전재와 비교하여, 산불 피해재는 상대결정화도가 다소 높았으며, 생재함수율과 접선 및 방사단면 흡수량은 다소 낮게 나타났다. 수축율 및 팽윤율과 기본밀도는 정상재와 거의 유사한 값을 보여주었다. Anatomical and physical characteristics of damaged wood by forest fire and sound wood of Pinus densifilora were examined. Granular substances were found in resin canals, epithelial cells and ray parenchyma cells of damaged wood, but the other distinctive marks of wood structure in damaged wood were not observed. Damaged wood showed slightly higher relative crystallinity in outermost growth ring than sound wood. Green moisture content and water absorptions both in tangential and radial sections of damaged wood were lower than those of sound wood. There were no significant differences in shrinkage, swelling and basic density between damaged and sound woods.

솔잎혹파리 피해 소나무재의 해부 및 물리학적 특성

황원중,권구중,이찬용,김남훈 강원대학교 삼림과학연구소 2001 Journal of Forest Science Vol.17 No.-

솔잎혹파리 피해 소나무재의 특성을 이해하고 효율적인 이용방법을 모색하기 위한 기초자료를 얻기위하여 솔잎흑파리 피해재의 해부 및 물리학적 성질을 조사하여 정상재와 비교 및 검토하였다. 그 결과, 솔잎혹파리 피해재는 정상재에 비해 축방향 수지구 및 수평수지구의 수가 많았고 위연륜이 출현하는 특징을 나타냈다. 또한 솔잎흑파리 피해재가 정상재보다 변 · 심재 모두 수축 · 팽윤율이 높았으며 변재부의 생재함수율은 정상재에 비해 다소 낮았다. 압축강도와 휨강도는 정상재보다 다소 낮았으나 전단강도는 거의 비슷한 값을 보여주었다. The objective of this work is to examine anatomical and physical characteristics of wood damaged by pine needle gall midge(PNGM, Thecodiplosis japonensis Uchida et Inouye) in Pinus densiflora. In anatomical characteristics, it was noted that the number of axial and radial resin canals in the damaged wood was higher than that in sound wood. In damaged wood, green moisture content of sapwood and swelling and shrinkage was higher than sound wood Both longitudinal compressive strength and bending strength of the damaged wood were lower than those of sound wood. On the other hand, shearing strength of damaged wood was similar to that of sound wood.Key word : Pinus densiflora, Thecodiplosis japonensis Uchida et Inouye, annual ring width, resin canal

종설 : 당뇨병성 위 마비

권중구 ( Joong Goo Kwon ) 대한내과학회 2011 대한내과학회지 Vol.81 No.2

Diabetic gastroparesis is a complication that often occurs in long-standing diabetic patients and it is characterized by delayed gastric emptying and upper gastrointestinal symptoms. The pathophysiology of gastroparesis is complex and poorly understood but substantial advances in knowledge about it have been gained from experimental studies of gastric tissue in animal models and humans with diabetes. Several abnormalities in diabetes might result in gastroparesis, including autonomic neuropathy, enteric neuropathy, abnormalities of interstitial cells of Cajal and smooth muscle cells, acute hyperglycemia and psychological dysfunction. Scintigraphic measurement of solid emptying is regarded as gold standard diagnostic technique for comparison of newer diagnostic modalities such as ultrasound, breath test and MRI. The available therapeutic options include dietary modification, optimization of glycemia, pharmacological interventions, endoscopic treatment, and gastric electrical stimulation. The efficacy of current treatment remains suboptimal and the search for more specific and effective treatments will likely be needed. (Korean J Med 2011;81:174-184)

위장관 점막하 종양의 조직 진단 추정에서 내시경초음파검사의 정확도

권중구 ( Joong Goo Kwon ),김은영 ( Eun Young Kim ),김영섭 ( Young Sup Kim ),천종운 ( Jong Woon Chun ),정진태 ( Jin Tae Chung ),유성수 ( Sung Soo You ),하형근 ( Hyung Keun Ha ),이창형 ( Chang Hyeong Lee ),김호각 ( Ho Gak Kim ),조 대한소화기학회 2005 대한소화기학회지 Vol.45 No.2

과민성 장증후군 치료에 관한 임상진료지침

권중구 ( Joong Goo Kwon ),박경식 ( Kyung Sik Park ),박정호 ( Jung Ho Park ),박재명 ( Jae Myung Park ),박철희 ( Cheol Hee Park ),이광재 ( Kwang Jae Lee ),박효진 ( Hyo Jin Park ),이종철 ( Jong Chul Rhee ) 대한소화기학회 2011 대한소화기학회지 Vol.57 No.2

Traditional symptom-based therapies of irritable bowel syndrome (IBS) are directed at the relief of individual IBS symptoms, but they are often of limited efficacy in addressing the entire symptom complex. Combinations of drugs to target bothersome symptoms are suggested as the first-line pharmacologic treatment. Increasing knowledge of the pathophysiology and molecular mechanisms of IBS has resulted in the development of several new therapeutic approaches. Thirteen consensus statements for the treatment of IBS were developed using the modified Delphi approach. Exclusion diets have modest efficacy in improving symptoms in some IBS patients. Symptom-based therapies with dietary fiber, bulking agents, laxatives, antispasmodics and laxatives are effective in the improvement of some individual symptoms, e.g. dietary fiber and bulking agents for constipation, laxatives for constipation, antispasmodics for abdominal pain and discomfort, antidiarrheals for diarrhea. 5HT3 receptor antagonists and 5HT4 receptor agonists are effective in the relief of global IBS symptoms and individual symptoms such as abdominal pain and abnormal bowel habits. A short term course of nonabsorbable antibiotics may improve global IBS symptoms, particularly in patients with diarrhea- predominant IBS. Some probiotics appear to have the potential benefit in improving global IBS symptoms. Selective C-2 chloride channel activator is more effective than placebo at relieving global IBS symptoms in patients with constipation-predominant IBS. Both tricyclic antidepressants and selective serotonin reuptake inhibitors are equally effective in relieving global IBS symptoms, and have some benefits in treating abdominal pain. Certain types of psychologic therapy may be effective in improving global symptoms in some IBS patients. Further studies are strongly needed to develop better treatment strategies for Korean patients with IBS. (Korean J Gastroenterol 2011;57:82-99)

포스터 전시 : 상부위장관 7 ; 식도게실을 동반한 하부식도 근륜 1예

권중구 ( Joong Goo Kwon ),박경찬 ( Gyung Chan Park ),유길종 ( Kil Jong Yu ),김은영 ( Eun Young Kim ),이창형 ( Chang Hyeong Lee ),김호각 ( Ho Gak Kim ),배정동 ( Jyung Dong Bae ) 대한소화기학회 2002 대한소화기학회 추계학술대회 Vol.2002 No.-

급성담관염의 원인균주와 항생제감수성의 시간흐름에 따른 변화

권정석 ( Jeong Seok Kwon ),한지민 ( Ji Min Han ),김태원 ( Tae Won Kim ),오지혜 ( Ji Hye Oh ),권현희 ( Hyun Hee Kwon ),정진태 ( Jin Tae Jung ),권중구 ( Joong Goo Kwon ),김은영 ( Eun Young Kim ),김호각 ( Ho Gak Kim ) 대한소화기학회 2014 대한소화기학회지 Vol.63 No.5

Background/Aims: We evaluated changes of causative pathogen in acute cholangitis and their antimicrobial susceptibility over six years and differences between community-acquired and hospital-acquired acute cholangitis at our institution. Methods: Medical records of 1,596 patients with acute cholangitis and biliary drainage between August 2006 and August 2012 were reviewed retrospectively. Cases were divided according to time: period 1 (August 2006-December 2008, n=645, 40.4%), period 2 (January 2009-August 2012, n=951, 59.6%). Cases were divided according to community-acquired cholangitis (n=1,397, 87.5%) and hospital-acquired cholangitis (n=199, 12.5%). Causative pathogens and antimicrobial susceptibility were investigated in each group. Results: Causative pathogen was isolated from bile culture in 1,520 out of 1,596 cases (95.2%). The three most frequently isolated Gram-negative bacteria were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n=485, 30.4%), E. coli (n=237, 13.2%), and Citrobacter freundii (n=110, 6.9%). Between periods 1 and 2, prevalence of ESBL-producing E. coli and Klebsiella pneumoniae did not show significant change (36.7% vs. 32.1%, p=0.073; 6.6% vs. 6.2%, p=0.732). C. freundii showed a significant increase from period 1 to period 2 (1.7% vs. 13.2%, p=0.000). In both time periods, imipenem was the antimicrobial agent showing the highest rate of susceptibility (93.3% vs. 93.9%, p=0.783). Higher prevalence of ESBL-producing E. coli and C. freundii was observed in the hospital-acquired cholangitis group (52.1% vs. 31.2%, p=0.000; 15.9% vs. 7.3%, p=0.001). Conclusions: The most common causative pathogen of acute cholangitis was ESBL-producing E. coli. Prevalence of C. freundii increased over the time period. Imipenem should be reserved as an alternative for resistant pathogens.