• 응용통계연구
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• 제33권6호
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• pp.777-789
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• 2020

COVID-19는 지난 2019년 12월부터 중국에서 발생하여 전세계적으로 확산된 대유행병이 되었다. 본 연구에서는 한국 질병 관리 본부에서 공개한 오픈 자료를 이용하였으며 시각화 기법을 통해 확진자의 남녀별 지역별 추세를 조사하였다. 또한 평균 바이러스 잠복기간을 추정하기 위해 감염원이 알려진 두 감염 그룹의 증상 발현 시점과 양성 확진 시점을 활용하였다. 하지만 양성 확진자 중 86%가 무증상으로 정확한 증상 발현시점을 알 수 없었다. 또한 주어진 자료에서는 감염시점도 알려져 있지 않아 감염시점과 증상 발현 시점차로 정의되는 잠복기간은 정확하게 측정하기가 어렵다. 이에 생존 분석의 한 기법인 구간 중도 절단을 적용하여 잠복기간의 분포를 추정하였다. 여러가지 모수 분포를 적용한 결과 최적의 분포하에서 평균 잠복 기간은 5.4일 (95% 신뢰구간 (4.70,6.01)일)이었다. 본 분석에서는 확진자 표본을 이용하여 치사율과 치유율을 구하기 위해 경쟁 위험 모형을 적용하였다. 분석 결과 50대이상의 치사 위험률은 50대미만 그룹의 30배이상이며 남성 양성 확진자가 사망할 확률이 더 높았다. 또한 여성이고 나이가 젊고 무증상일 때 치유될 가능성이 더 높았다.

• Journal of Advanced Marine Engineering and Technology
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• 제22권2호
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• pp.139-145
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• 1998

Filament winding method is widely used for composite fabrications using low viscosity liquid for-mation and processing asymmetrical structures of pressure vessel pipe rocket motor case etc. The filament winding method is affected by several parameters such as pot life of process time viscosi-ty of resin filament winding temperature and schedules curing condition and post curing condi-tion of resin. To develope high functional composite materials the rotation(5, 15, 20, 30rpm) of the winding machine was controlled by D.C motor. And the wiper to give proper tension was equipped between strand and resin bath. The resin is hooked by the design wiper. The adequate cure schedule was found by DSC. NOL ring test is carried out to investigate the basic physical properties such as design technology. The void contents in filament winding is generally higher than that of the prepreg laminated plate. These high contents of void can make a crack in resin in spite of low deformation. These problem was solved by giving tension in processing. To improve the characteristics of fiber volume fraction void contents resin/fiber bonding the winding speedc is changed under constant tension. It was found that resin impregnation was not different from in fiber contents void contents at the range of 0.5~1kg tension but it was found that resin was not impregnated at the above of 1.5kg tension. In burst test a pure PE liner was failed at a nozzle part under the $14kg/\textrm{cm}^2$ pressure but a pressure vessel of CNG was failed at a cylinder part under the $200kg/\textrm{cm}^2$ pressure.

• Biomolecules & Therapeutics
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• 제2권4호
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• pp.376-382
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• 1994

Repeated injections of low-doses of mercuric chloride in rats or mice induce polyclonal activation which includes the induction of anti-glomerular basement membrane (GBM) antibodies and circulating immune complex and it results in nephritis. Because this disease is autoimmune mediated disease resulted from immune dysfunction, immunomodulators are used to control the symptoms or to cure the disease. Irpex lacteus Fr. is a kind of new medicinal fungus. The polysaccharide fraction extracted from submerged fermentation of Irpex lacteus Fr. decreased the serum agglutinin, serolysin and IgM plaque forming cells in normal mice. The hitherto obtained clinical results suggested that it significantly improved the oligourea, edema, and hypertension in patients who have nephritis. To elucidate the action-mechanisms of Irpex lacteus Fr., we established the experimental model of HgCl$_2$induced polyclonal activation by intraperitoneal administrations of HgCl$_2$to mice. To assess the immunomodulating effect of Irpex lacteus fraction, we Investigated its effects on the mitogen induced proliferation and IgM PFC counts of splenic lymphocytes in mice during the treatment of HgCl$_2$. The Irpex lacteus polysaccharide reduced the abnormally increased mitogen induced Iymphocyte proliferation and IgM PFCs to almost normal levels. And the Irpex lacteus polysaccharides prevented the increasement of serum immunoglobulin level induced by HgCl$_2$. These data suggested that the Irpex lacteus polysaccharides might have the immunomodulating activity to prevent and /or improve the HgCl$_2$ induced autoimmune disease.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.126-126
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• 1998

Studies on natural products are of great interest, due to the limits in development of synthesized medicine and its side effects. Deer antler is the most popular cure-all type drug among Asian folk medicines. In this study, we newly isolated the biologically active components from chloroform extract and 70% ethanol extract of deer antler, and analyzed their structures. First, the structure of monoacetyldiglyceride in deer antler was identified. To investigate the structure-activity relationship of monoacetyldiglycerides, we synthesized diverse substituted glycerides from glycerol, and confirmed their structures by spectroscopic methods. Among seven structurally-interesting compounds tested in this study, compound 1,2,3,5, and 6 showed activity toward [Ca$\^$2+/]$\_$i/ increase in fura-2 loaded rat pancreatic acinar cells. Second, 70% ethanol extract of deer antler stimulated insulin release from rat pancreatic islets. We found the most effective fraction was CN-Es-8 in 70% ethanol extract, and it increased intracellular Ca$\^$2+/ concentration in pancreatic ${\beta}$-cell.

• Applied Biological Chemistry
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• 제38권4호
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• pp.364-369
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• 1995

목단피의 mouse 복수암에 대한 항암성을 다른 생약제의 항암성과 비교하여 연구하였다. 천연생약제(목단피, 주목, 울금, 인경쓱, 여정실, 맥문동) methanol 추출물을 hexane, chloroform ($CHCl_3$), ethylacetate (EtOAc), butanol (BuOH)로 fractionation하여 mouse leukemia L1210 cell과 Sarcoma 180 (S-180) cell에 강한 독성을 나타낸 fraction에 대해 mouse 복수암 억제실험을 실시하였다. 복수형 종양세포 S-180을 ICR mouse (male, $6{\sim}7$주령, $23g{\pm}3g$, 처리당 7마리)의 복부에 주사 ($1{\times}10^{6}$ cells/0.1 ml PBS)한 1일 후 부터 10% DMSO에 용해한 시료 ($30{\mu}g/g$ body weight)를 매일 0.1ml씩 10일간 주사하고 수명연장 효과와 몸무게의 변화를 조사하였다. 처리 fraction 중에서 목단피의 EtOAc fraction이 가장 강한 항암성을 보였는데, 수명연장에서는 대조구의 17.2일 (100%)에 비하여 28.7일로서 167%로 연장되었으며, 체중 증가율도 대조구보다 낮았다 (p<0.05). 목단피의 농도별 (5, 10, 30, $60{\mu}g/g$ body weight) 항암효과는 $30{\mu}g$에서 가장 높았고, $60{\mu}g$처리구 에서는 독성이 나타났다. 목단피의 EtOAc fraction으로부터 GC-MS에 의해 잠정적으로 동정된 2-methoxyphenol, 1-(4-hydroxy-3- methoxyphenyl)-ethanone, 8-methyl-2,4(1H,3H)-pteridinedione, 2,5-furandicarboxylic dimethyl ester 가 mouse 복수암 억제에 관련이 있는 주요 화합물로 추정된다.

• 한국식품영양과학회지
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• 제35권2호
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• pp.132-138
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• 2006

혈전성 질환을 예방 및 치료할 수 있는 트롬빈 직접 저해제 개발은 전 세계적으로 지속적으로 이루어지고 있다. 본 연구에서는 안전성이 확보된 식용 및 약용식물로부터 트롬빈 직접저해제를 탐색하였으며, 그 결과 메밀 종자의 메탄올 추출물 및 주정 추출물에서 강력한 트롬빈 저해활성을 확인하였다. 메탄올 추출물의 순차적 유기 용매 분획 결과 부탄올 및 에틸아세테이트 분획물에서 가장 우수한 트롬빈 저해활성을 나타내었다. 특히 주정 추출물의 부탄올 분획의 경우 $312.5{\mu}g/mL$의 낮은 농도에서도 $2,000\%$이상의 트롬빈 저해 활성을 나타내어, 아스피린보다 매우 효율적으로 혈전 생성을 억제함을 확인하였다. 활성성분은 30 KD 이상의 고분자 비단백질 성분임을 확인하였으며, 산 및 열처리에 의해 급격한 활성 감소가 나타나, 활성 물질의 효율적인 이용을 위해서는 메밀 종자의 비열, 비산 처리공정이 필요하리라 추측되었다. 또한 활성 분획물은 ICR 마우스를 이용한 폐색전 실험, 전뇌 허혈성 실험 및 치사유발실험에서 아스피린보다 우수한 혈전성 마비 억제, 혼수방지 및 치사억제 활성을 보여, 혈행 개선제 및 항혈전제로 개발 가능함을 제시하였다.

• 대한두경부종양학회지
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• 제22권2호
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• pp.130-136
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• 2006

Introduction : The sensitivity of tumor cells to radiotherapy is a critical determinant of local control and potential cure in advanced head and neck squamous cell carcinoma(HNSCC). The emergence of radioresistant tumor cells is an obstacle to cancer therapy. Most radioresistant cells have a higher proportion of cells in the Sphase of the cell cycle and a lower apoptotic fraction than radiosensitive cells. HSV replication is increased in cells that have higher S-phase fractions. NV1066 is an oncolytic herpes simplex virus type-1 mutant. We hypothesized that NV1066 replication and cytotoxicity are increased in radioresistant cells. The purpose of this study is to evaluate the antitumor efficacy of NV1066 to treat radioresistant HNSCC. Methods : Radioresistant cells were selected by treating five HNSCC cell lines with repeated conventional fractionated doses of radiation(2Gy/day), using a Cs-137 irradiator, up to a cumulative dose of 70Gy. Clonogenic cell survival and S-phase fractions were compared between radioresistant and parental radiosensitive cells. The two cell populations were then treated with NV1066 to examine viral replication, by the viral plaque assay and viral cytotoxicity. Results : Fractionated irradiation resulted in the selection of radioresistant cells. Radioresistant cells had a higher S-phase fraction(42.9%) compared to parental cells(26.2%). NV1066 replication in radioresistant cells was 7.4 times higher than in parental cells(p<0.01). Treatment with NV1066 resulted in increased cytotoxicity of 24.5% in radioresistant cells compared to parental cells(p<0.05). Conclusion : NV1066 showed increased viral replication and cytotoxicity in radioresistant HNSCC cell lines. These findings suggest a potential clinical application for this oncolytic viral therapy as treatment for radioresistant head and neck cancers.

• Mycobiology
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• 제40권1호
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• pp.47-52
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• 2012

$Elfvingia$ $applanata$, a medicinal mushroom belonging to Basidiomycota, has been used in the effort to cure cancers of the esophagus and stomach, and is also known to have inhibitory effects on hepatitis B virus infection. The hot water soluble fraction (as Fr. HW) was extracted from fruiting bodies of the mushroom. $In$ $vitro$ cytotoxicity tests showed that hot water extract was not cytotoxic against cancer cell lines such as Sarcoma 180, HT-29, HepG2, and TR at concentrations of 10-2,000 ${\mu}g/mL$. Intraperitoneal injection with Fr. HW resulted in a life prolongation effect of 45.2% in mice previously inoculated with Sarcoma 180. Treatment of Fr. HW resulted in a 2.53-fold increase in the numbers of murine spleen cells at a concentration of 50 ${\mu}g/mL$, compared with control. Incubation of murine spleen cells with Fr. HW at a concentration of 500 ${\mu}g/mL$ resulted in improved immune-potwntiating activity of B lymphocytes through an 8.3-folds increase in alkaline phosphatase activity, compared with control. Fr. HW generated 12.5 ${\mu}M$ of nitric oxide (NO) when cultured with RAW 264.7, a mouse macrophage cell line, at the concentration of 50 ${\mu}g/mL$, while lipopolysaccharide, a positive control, produced 15.2 ${\mu}M$ of NO. Therefore, the results suggested that antitumor activities of Fr. HW from $E.$ $applanata$ might, in part, be due to host mediated immunostimulating activity.

• Journal of Korean Neurosurgical Society
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• 제56권5호
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• pp.405-409
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• 2014

Objective : To determine the efficacy of endoscopic surgery in combination with long-acting somatostatin analogues (SSAs) in treating patients with growth hormone (GH)-secreting pituitary tumor. Methods : We performed retrospective analysis of 133 patients with GH producing pituitary adenoma who underwent pure endoscopic transsphenoidal surgery in our center from January 2007 to July 2012. Patients were followed up for a range of 3-48 months. The radiological remission, biochemical remission and complication were evaluated. Results : A total of 110 (82.7%) patients achieved radiological complete resection, 11 (8.2%) subtotal resection, and 12 (9.0%) partial resection. Eighty-eight (66.2%) patients showed nadir GH level less than 1 ng/mL after oral glucose administration. No mortality or severe disability was observed during follow up. Preoperative long-acting SSA successfully improved left ventricle ejection fraction (LVEF) and blood glucose in three patients who subsequently underwent success operation. Long-acting SSA (20 mg every 30 days) achieved biochemical remission in 19 out 23 (82.6%) patients who showed persistent high GH level after surgery. Conclusion : Endoscopic transsphenoidal surgery can biochemically cure the majority of GH producing pituitary adenoma. Post-operative use of SSA can improve biochemical remission.

• Composites Research
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• 제17권5호
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• pp.1-6
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• 2004

HDPE (high density polyethlyne) 라이너와 금속 boss를 가진 복합재료 압력용기가 필라멘트 와인딩 공정에 의해 개발되었다. 이 용기의 끝 부위는 dome-shape 부위 그리고 용기의 중앙부는 cylinder-shape로 형성되었다. 용기를 구성하는 재료인 HDPE, 수지 그리고 강화섬유와 같은 용기재료에 대해 환경실험이 1년 이상 실행되었다 Boss 설계는 FEM 해석으로 가스 누출을 최대한 방지해 주는 것으로 확인되었다. 실험적인 방법에 의해 가장 이상적인 fiber tension이 얻어졌고, image analyzer에 의해 측정된 섬유의 체적율, $\textrm{V}_{f}$,는 실린더에서 55.4 %, dome part에서 55.6 % 이었다. Winding pattern은 용기의 파괴가 실린더 부위에서 일어나도록 dome 부위의 복합재료 두께조절을 하도록 프로그램 되었다 경화 중 용기는 돌려졌었고 고정 내부압력 0.62 bar를 가함으로서 최종용기의 파괴압력이 28 % 향상되었다. Under-wound, fully wound된 용기의 파괴 및 피로시험결과를 충족하였다.