펄프지료의 pH가 고해에 미치는 효과

김창락,문상환,김재옥,김철환,박종열 경상대학교 농업생명과학연구원 2003 농업생명과학연구 Vol.37 No.4

펄프 섬유를 이용해서 종이를 제조하기 위해서는 반드시 섬유를 물에 현탁시키는 해리와 섬유 벽에 물리적 변화를 부여하는 고해의 과정을 거쳐야 하고, 이 과정에서 섬유는 팽윤 과정을 겪게 된다. 섬유가 물에 의해 팽윤이 잘 될수록 유연성이 좋아지기 때문에 종이의 물리적 성질이 훨씬 향상된다. 펄프를 물에 현탁시키는 전처리 과정에서 NaOH를 첨가하여 침지과정에서 섬유의 팽윤이 더 잘되게 하기 위함인데, NaOH의 처리량을 증가시킴에 따라 고행 동안 섬유벽의 팽윤이 촉진되어 종이의 강도적 성질이 향상되는 것을 확인할 수 있었다. Pulp fibers must be disintegrated and refined before papermaking. During refining, internal fibrillation of fiber walls are generated, leading to fiber wall swelling. Owing to improved fiber flexibility, strength properties of paper are remarkably improved. This study aimed to explore how NaOH addition to pulp suspension before refining would affect fiber swelling in addition to paper properties. As the addition ratio of NaOH increased, strength properties of paper were greatly improved due to the increase of fiber wall swelling. The extent of fiber wall swelling according to pH was observed by paraffin embedding and physical sectioning. In conclusion, it became evident that higher pH in fiber suspension gave positive contribution to fiber wall swelling during refining.

위절제술 환자의 표준진료지침 개발 및 적용 효과

김은희,김철규,이순교,김순덕,이혜옥,권정순,이경미,이민미,심순미,유용만,신종식,강은희,이상일,김병식,오성태,육정환,박수길 한국의료QA학회 2003 한국의료질향상학회지 Vol.10 No.2

Background : Gastric cancer is the most common malignant tumor in Korea. surgical operation is one of the major treatment modalities for gastric cancer patients. Therefore, gastrectomy is one of the most common procedures in General Surgery. There were variation in length of hospital stay and medical treatment for gastrectomy between three surgeons at Asan Medical Center. Clinical pathways have received considerable attention as a tool for recucing the medical practice variation, increasing the efficiency of care process, and improving the quality of care. The aim of this study was to evaluate the effect of a clinical pathway for gastrectomy in gastric cancer patients. Methods : The clinical pathway for gastrectomy was developed and implemented by a multidisciplinary group in Asan Medical Center. A computerized clinical pathway program was developed and revised after a pilot test. A total of 145 patients underwent gastrectomy by three surgeons at Asan Medical Center. We compared the length of hospital stay, patient satisfaction, and unplanned readmission rate between the pre-pathway group(n=67) and the post-pathway group(n=78). We also investigated the degree of satisfaction among the physicians and nurses who were main end-users of the clinical pathway. Results : The clinical pathway was applied to all target patients. The average length of hospital stay was shortened from 12.7days to 10.6days(p<0.01). The degree of patient satisfaction with the care process changed from 90.3% to 89.2% after the implementation of the clinical pathway, but the difference was of satistically significant(p=0.761). Unplanned readmission rate was 2.9% in the pre-pathway group. More than 90% of physicians and nurses answered that the clinical pathway had been a useful tool in their medical practice. Conclusions : The findings of the study demonstrated that implementation of the clinical pathway for gastrectomy produced substantial reduction in the length of hospital stay while improving the quality of patient outcomes. The computerized clinical pathway program can be used as one of the powerful patient management tools for reducing the practice variations and increasing the efficiency of care process in Korea hospital settings.

냉동 제대혈 세포의 체외 증폭

김삼용,김철희,배광봉,김현수,박상준,김종숙,윤환중,조덕연 충남대학교 암연구소 1998 癌共同硏究所 硏究誌 Vol.2 No.1

Background : Cord blood(CB), which has no HLA restriction, is an alternative to bone marrow for hematopoietic stem cell transplantation. The use of cord blood, however, is limited by the number of progenitor/stem cells necessary to reconstitute the older child or adult. Therefore, ex vivo expansion of CB could have tremendous impact on diverse clinical settings. We studied the ex vivo expansion of isolated population of CD34_(+) cells from cryopreserved CB cells. Methods : CD34 cells were isolated from cryopreserved CB mononuclear cells. Purified cells were cultured with various combinations of hematopoietic growth factors including erythropoietin(EPO), stem cell factor(SCF), granulocyte-colony-stimulating factor(G-CSF), gra-nulocyte, macrophage-colony-stimulating factor(GM-CSF), interleukin-1β(IL-1β), 1L-3, and IL-6. After 7, 10 or 14 days of culture, the fold increases of colony-forming unit- granu-locyte, macrophage(CFU-GM), burst-forming unit-erythroid(BFU-E), colony-forming unit-mix (CFU-Mix), and high proliferative potential colony-forming cell(HPP-CFC) were evaluated. Results : Ten-day culture with the combination of EPO, SCF, G-CSF, IL-1β, and IL-3 resulted in a median of 60-fold increase of CFU-GM, which was greater than those with the combinations of less than 5 growth factors. The addition of IL-6 or GM-CSF to this combination did not enhance CFU-GM expansion. Ten-day culture was significantly superior to 7-day culture for CFU-GM expansion. Prolongation of culture to 14 days, however, revealed decreased expansion of CFU-GM compared to 10 days. BFU-E and CFU-Mix were expanded to 2~5 folds in 7-day culture with the combination of EPO, SCF, and G-CSF. Further expansion was not achieved in 10-day culture and colonies disappeared in 14-day culture. HPP-CFC was expanded to a median of 7.5 folds in 7-day culture with the combination of EPO, SCF, G-CSF, IL-1β, IL-3, and IL-6. Neither 10-day or 14 day-culture enhanced expansion of HPP-CFU. Conclusion : Cryopreserved cord blood cells maintain ex vivo expansion potential. In our system, 10-day culture with the combination consisting of EPO, SCF, G-CSF, IL-1β, and IL-3 seems to be adequate for hematopoietic progenitor/stem cell expansion from cryopreserved cord blood cells.

단기배양을 통한 말초혈액 CD34 양성세포의 체외증폭

박상준,김철희,배광봉,김현수,김종숙,윤환중,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.1

Background: It is suggested that clinical practice in the areas of bone marrow transplantation and gene therapy might rely on the ex vivo expansion of hematopoietic stem/progenitor cells. However, the condition for ex vivo expansion of hematopoietic progenitor cells is not well established. The authors pursued a series of experiments to define the proper conditions for the expansion of hematopoietic cells in the short-term liquid suspension culture of mobilized peripheral blood CD34+ cells. Methods: 1.0ml cultures were initiated with 9×10^3 PB CD34+ cells, which were isolated from PB mononuclear cells (MNCs) by high-gradient cell sorting, in 12 well plates with the various combinations of hematopoietic growth factors(HGF). The following recombinant human HGFs were used: stem cell factor(SCF) 100ng/ml, granulocyte colony-stimulating factor(G-CSF) 100ng/ml, GM-CSF(granulocyte, macrophage colony-stimulating factor) 100ng/ml, interleukin-1 beta(IL-1B) 1ng/ml, interleukin-3(IL-3) 20ng/ml, interleukin-6 (IL-6) 100ng/ml. At the end of culture, colony-forming cells were evaluated by semisolid clonogenic assay. Results: 1) Using the high-gradient magnetic sorting system, CD34^+ cells were isolated with a yield of 40 3% 2) In 7 day culture of PB CD34^+ cells(9×10^3 cells), nucleated cells expanded mean 10×10^3(range, 9 to 20×10^3) with the addition of SCF alone, 35×10^3(range, 10 to 60×10^3) with SCF plus G-CSF plus GM-CSF, and 130×10^3(range, 40 to 300×10^3) with the combination of SCF, G-CSF, IL-1, IL-3, IL-6, GM-CSF. In 14 day culture, nucleated cells expanded 10×10^3 to 1,860×10^3 with combination of human hematopoietic growth factors. 3) In 10 day culture without medium change of PB CD34^+ cells, CFU-GM numbers expanded 16. 5 fold(range, 7 to 59 fold) with the addition of SCF plus G-CSF plus Il-1 plus IL-3, 31.3 fold(range, 20.5 to 101.1 fold) with the combination of SCF, G-CSF, IL-1, IL-3, GM-CSF. In 14 day culture with or without medium change of PB CD34^+ cells was inferior to 10 day culture for CFU-GM expansion. 4) There was no significant difference for CFU-GM expansion between five growth factors(SCF,G-CSF,IL-1,IL-3,GM-CSF) and six growth factors(five growth factors plus IL-6). Conclusion: The authors could confirm that short-term suspension culture of peripheral blood CD34+ cells could expand hematopoietic progenitor cells. Ten-day culture with medium change of CD34+ cells with the addition of five growth factors, i.e. SCF, G-CSF, IL-1B, IL-3, and GM-CSF, might be the most efficient in this system.

상호상관 함수를 이용한 지중선로 고장점 추정

朴星完,林泳範,鄭州桓,成洛煥,金喆煥,申明徹 成均館大學校 科學技術硏究所 1994 論文集 Vol.45 No.2

This paper is intended as an investigation of fault location for underground line. Over the past few decades a considerable number of studies have been made on protection of underground line. However, these approaches require the interruption of electric power supply from source for fault location estimation. Therefore, we proposed fault location algorithm for underground line protection without interruption of electric power supply. Cross correlation function is used in this algorithm. Also, EMTP data is used to demonstrate the capability of the proposed fault location algorithm.

불응성 자가면역질환에서의 자가조혈모세포이식

민도준,양동원,민창기,김완욱,이상헌,박성환,김동욱,이종욱,조철수,민우성,김범생,김호연,김춘추 대한조혈모세포이식학회 2001 대한조혈모세포이식학회지 Vol.6 No.1

배경: 기존의 치료에 불응하고 예후가 불량한 자가면역질환 환자들에게 최근 고용량 면역억제 및 조혈모 세포이식이 새로운 치료방법으로 대두되고 있다. 저자들은 다발성 경화증(multiple sclerosis, MS) 및 류마티스 관절염(rheumatoid arthritis, RA) 등 2명의 자가면역질환 환자들에서 자가조혈모세포 이식을 시행하였다. 방법: 말초혈액 조혈모세포 가동화를 위하여 cyclophosphamide (4 g/㎡) 및 granulocyte colony stimulating factor (10 g/kg/day)를 투여하였고, CD34+ 세포를 분리·채집 하였다, 이식 전처치로 MS 환자에서 BEAM 및 antihymocyte globulin (ATG) (3.75 mg/kg), RA 환자에서 fludarabine (180 mg/㎡), ATG (10 mg/kg)와 busulfan (8 mg/kg)을 투여하였다. 결과: 호중구 수가 500/㎕ 이상으로 회복되는 기간은 MS 환자에서 9일, RA 환자에서 15일이었다. 혈소판이 20.000/㎕ 이상으로 회복되는 가간은 RA 환자에서 9일 이었고, MS 환자에서는 혈소판 감소증이 발생하지 않았다. 비혈액학적 독성으로 MS 환자에서 WHO 1도의 오심 및 점막염이 관찰되었다. MS 환자는 이식 6개월 후까지 시력감소가 남아있었으나, 이식전에 관찰되던 감각이상 및 운동장애 등의 신경학적 이상 소견은 더 이상 관찰되지 않았다. RA 환자는 이식 1개월 후 관절 증상 및 검사소견의 호전을 보였다. 결론: 불응성 자가면역질환 환자에서 고용량 면역억제 및 조혈모세포이식은 적은 독성으로 높은 치료효과를 기대할수 있으며, 향후 이 시술의 임상적 의의를 규명하기 위하여 전향적이고 장기적인 연구가 필요할 것으로 사료된다. Background: High-dose immunosuppressive therapy followed by autologous hemathpoietic stem cell transplantation (HSCT) has been proposed as a new approach to treat severe, refractory autoimmune diseases. We describe two patients with refractory autoimmune diseases (one multiple sclerosis 〔MS〕and one rheumatoid arthritis〔RA〕) who underwent T-cell-depleted autologous peripheral bleed stem cell transplantation for the first time in Korea. Methods: We mobilized autologous stem cells with cyclophisphamide (4 g/㎡) and granulocyte colony-stimulating factor (10 ㎍/kg/day). Stem cells were enriched ex vivo using CD34-positive immunoselection and reinfused after high-dose chemotherapy with BEAM and antithymocyte globulin (ATG) (3.75 mg/kg) in MS, or fludarabine (180 mg/㎡), ATG (10 mg/kg) and busulfan (8 mg/kg) in RA. Results: The engraftment with an absolute nerutrophil count greater than 500㎕ occurred on day 9 in MS and 15 in RA, respectively. The time to nontransfused platelet count greater than 2.000/㎕ was 9 day in RA. MS patient did not show ant episode of thrombocytopenia. Regimen-related non-hematopoietic toxicity was minimal. For 6 months since HSCT, them patient with MS had been free from previously existed sensory and motor abnormalities except decreased visual acuity. Then patient with RA and only one tender joint and two mildly swollen joints with improvement in laboratory parameters at one month after HSCT. Conclusion: These results underscore the feasibility and potential efficacy of intensive immunosuppression followed by autologous HSCT for treatment of intractable autoimmune diseases. The durability of remission, however, remains to be clarified.

자연순환 온수 난방장치에서 열부하에 미치는 코일관 보일러의 형상인자들에 대한 연구

김철주,송기환 成均館大學校 科學技術硏究所 1992 論文集 Vol.42 No.2

So called "Saemaul-Boiler"is a domestic heating system composing a closed loop of tube, through which is circulating a hot water mobilized by natural convection effect in boiler. This heating system was simplified to a single phase closed thermo-loop, having an element of helically coiled tube heated externally by electric resistance wire. The investigation was put on some parameters of coil tube such as helix angle, curvature ratio and tube diameter in order to understand their effects on mass flow rate of working fluid in the loop system. From the results of the experiment it was shown that : 1) The heilx angle and diameter of coil tube might have a considerable importance on improuvement of thermal load by increasing mass flux of working fluid. 2) But the curvature ratio had relatively negligible effect.

하악골에 발생한 Primary Intraosseous Carcinoma의 치험례

김철환,김미숙 大韓顎顔面成形再建外科學會 1997 Maxillofacial Plastic Reconstructive Surgery Vol.19 No.2

The WHO separates odontogenic carcinomas into three groups : malignant ameloblastoma, primary intraosseous carcinoma(PIOC), and carcinomas arising from odontogenic epithelium including those arising from odontogenic cysts. In WHO criteria, primary intraosseous carcinoma is defined as a squamous cell carcinoma arising within the jaw, having no connection with the oral mucosa, and no developing from residues of odontogenic epithelium. This is a case of 52-year old man who had prolonged jaw pain and final diagnosis was primary intraosseous carcinoma(PIOC) on mandible. We obtained successful result after composite resection combined with hemimandibulectomy, RND, following reconstruction with latissmus dorsi myocutaneous flap, and postoperative radiation therapy.

벼 기계이앙 재배시 생장조절제 처리가 생육 및 도복에 미치는 영향

金正鎬,吳成煥,李哲遠,宋凡憲,朴相一 忠北大學校 農業科學硏究所 2002 農業科學硏究 Vol.19 No.-

The study was carried out to examine the effects of plant growth regulators, 2,4-D, IBP, and Inabenfide, on growth responses and lodging resistance of rice in cultivation of the machine transplanting The Chucheong cultivar of Japonica variety was used Growth responses including culm length and lodging index etc and rice yields were measured at major growth stages and harvest time Culm length was the shortest in the treatment of IBP + Inabenfide, shortening it to 106 cm compared to that of the control, showing the best application effect of the plant growth regulator The length of internode between third and fourth internodes of lower culm was shortened to 55cm with treatment of IBP + Inabenfide compared to that of the control and it between fourth and fifth internodes was shortened to 2.9 cm with treatment of Inabenfide, showing the best effectiveness 50% of lodging was reduced by treating the plant growth regulator, 45 lodging index with treatment of IBP + Inabenfide compared to 90 of the control Resulting to reducing the lodging, rice yield was increased more with treatment of IBP + Inabenfide, to about 87%, than that of the control.

무인잠수정의 3-D 위치 계측시스템 개발

김희철,임종환,강철웅 제주대학교 공과대학 첨단기술연구소 2003 尖端技術硏究所論文集 Vol.14 No.2

This paper presents a 3-D localization method of an autonomous underwater vehicle(AUV). Conventional methods of localization, such as LBL or SBL, require additional beacon systems, which reduces the flexibility and availability of the AUV. We use a digital compass, a pressure sensor, a clinometer and ultrasonic sensors for localization From the orientation and velocity information, a priori position of the AUV is estimated based on the dead reckoning method Based on the extended Kalman filter algorithm, a posteriori position of the AUV is, then, estimated by using the distance between the AUV and a mother ship on the surface of the water together with the depth information from the pressure sensor. Simulation results show the possibility of practical application of the method to the autonomous navigation of the AUV.