• 제목/요약/키워드: Half Life Time

검색결과 500건 처리시간 0.027초

Controlled release of nerve growth factor from heparin-conjugated fibrin gel within the nerve growth factor-delivering implant

  • Lee, Jin-Yong;Kim, Soung-Min;Kim, Myung-Jin;Lee, Jong-Ho
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제40권1호
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    • pp.3-10
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    • 2014
  • Objectives: Although nerve growth factor (NGF) could promote the functional regeneration of an injured peripheral nerve, it is very difficult for NGF to sustain the therapeutic dose in the defect due to its short half-life. In this study, we loaded the NGF-bound heparin-conjugated fibrin (HCF) gel in the NGF-delivering implants and analyzed the time-dependent release of NGF and its bioactivity to evaluate the clinical effectiveness. Materials and Methods: NGF solution was made of 1.0 mg of NGF and 1.0 mL of phosphate buffered saline (PBS). Experimental group A consisted of three implants, in which $0.25{\mu}L$ of NGF solution, $0.75{\mu}L$ of HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin was injected via apex hole with micropipette and gelated, were put into the centrifuge tube. Three implants of experimental group B were prepared with the mixture of $0.5{\mu}L$ of NGF solution, $0.5{\mu}L$ HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin. These six centrifuge tubes were filled with 1.0 mL of PBS and stirred in the water-filled beaker at 50 rpm. At 1, 3, 5, 7, 10, and 14 days, 1.0 mL of solution in each tubes was collected and preserved at $-20^{\circ}C$ with adding same amount of fresh PBS. Enzyme-linked immunosorbent assay (ELISA) was done to determine in vitro release profile of NGF and its bioactivity was evaluated with neural differentiation of pheochromocytoma (PC12) cells. Results: The average concentration of released NGF in the group A and B increased for the first 5 days and then gradually decreased. Almost all of NGF was released during 10 days. Released NGF from two groups could promote neural differentiation and neurite outgrowth of PC12 cells and these bioactivity was maintained over 14 days. Conclusion: Controlled release system using NGF-HCF gel via NGF-delivering implant could be an another vehicle of delivering NGF to promote the nerve regeneration of dental implant related nerve damage.

초순수내에서의 오존의 용해도와 세정효과 (The Solubility of Ozone in Deionized Water and its Cleaning Efficiency)

  • 한정훈;박진구;곽영신
    • 한국재료학회지
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    • 제8권6호
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    • pp.532-537
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    • 1998
  • 본 연구는 반도체 공정중 습식세정시 사용되는 초순수내에서의 오존의 거동과 오존이 주입된 초순수와 실리콘 웨이퍼와의 반응성에 대해 연구하였다. 초순수내 오존의 용해도는 주입되는 오존의 농도와 초순수의 온도가 낮을수록 증가하였고 주입되는 오존의 농도에 정비례하여 증가하였다. 초순수내 오존의 반감기는 초순수내 오존의 용해농도와 초순수의온도가 낮을수록 증가함을 나타내었고 반응차수는 약 1.5로 계산되었다. 초순수의산화환원전위(redox potential)값은 오존 주입시 5분 이내에 포화되어 일정한 값을 나타내었고 주입되는 오존의 농도가 증가함에 따라 약간 증가하였다. HF처리된 실리콘 웨이퍼는 오존이 2ppm 이상 용해된 초순수에서 세정하였을 때 1분 이내에 접촉각이 $10^{\circ}$미만의 친수성 표면을 형성하였고 piranha 세정액($H_2SO_4$$H_2O_2$의 혼합액)에 의해 형성된 자연산화막보다 오존이 주입된 초순수에 의해 형성된 산화막이 약간 더 두꺼움을 Spectroscopic Ellip-someter에 의해 관찰하였다. 오존의 농도가 1.5ppm에서 90초내에 계면활성제로 오염된 실리콘 웨이퍼를 piranha용액과 오존이 함유된 황산 그리고 오존이 함유된 초순수에서 세정시 오존이 함유된 초순수가 가장 탁월한 오염제거능력을 나타내었다.

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가루응애류 Caloglyphus sp.의 생태에 관한 연구 (Bionomics of Caloglyphus sp.(Acarina : Acaridae))

  • 박지두;김종국
    • Journal of Forest and Environmental Science
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    • 제13권1호
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    • pp.51-56
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    • 1997
  • 각(各) 항온조건(恒溫條件)에서 솔잎혹파리 3령 유충을 식이물로 공급하며 응애류 Caloglyphus sp. 의 발육특성(發育特性)과 증식능력(增植能力)을 조사하였다. 본 응애는 란(卵), 유충(幼蟲), 제(第)1약충(若蟲), 제(第)2약충(若蟲), 성충(成蟲)의 4발육단계를 경과하며, 란(卵)을 제외한 모든 발육충태는 솔잎혹파리 유충을 포식(捕食)하였다. 란(卵)부터 성충(成蟲)까지의 발육소요일수(發育所要日數)는 온도가 높을수록 짧았으며, 발육한계온도(發育限界溫度)는 $8.2^{\circ}C$, 유효적산온도(有效積算溫度)는 122.0일도(日度)이었다. $25^{\circ}C$항온에서 란(卵)부터 제(第)2약충(若蟲)까지의 생존율(生存率)은 66.4%으며, 성충의 평균수명(平均壽命)은 수컷이 12.3일, 암컷이 10.2일 이었다. 성충은 1~2일 경과후 산란하기 시작하여 산란기간 초기에 다수의 알을 낳았으며 일생동안 평균 360.6 개체를 산란(産卵)하였다. 발육소요일수(發育所要日數) 및 령별생존율(齡別生存率)과 산란수(産卵數)를 이용하여 산출한 순번석율(純繁殖率)(Ro)과 평균(平均) 세대기간(世代期間)(T), 내적자연증가율(內的自然增加率)($r_m$)은 각 101.1, 9.3일, 0.494/♀/일 이었다.

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현장 폭로실험에 의한 콘크리트 중 철근의 부식 임계 염화물량 평가 (Estimation of Critical Chloride Content for Corrosion of Reinforcing Steel in Concrete by Field Exposure Experiment)

  • 유경근;배수호;박재임;이광명;김지상
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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    • pp.585-588
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    • 2008
  • 염해환경 하에 있는 철근 콘크리트 구조물의 내구수명을 평가하기 위해서는 콘크리트 중 철근의 부식 임계 염화물량, 콘크리트의 염소이온 확산계수 및 표면 염소이온량과 같은 재료의 정량적인 물성 파악이 필수적이고, 이들이 콘크리트의 내구수명 평가시 주요변수로 이용되고 있다. 그러나, 이들은 콘크리트 배합비, 시멘트 종류 및 환경 조건 등과 같은 여러 요인에 의해 영향을 받는 것으로 알려져 있다. 따라서, 본 연구에서는 콘크리트 중 철근의 부식 임계 염화물량을 보다 실제적으로 평가하기 위하여 물-시멘트비 31%, 42%, 50% 및 70%에 대해서 각주형 콘크리트를 제작한 다음, 이들에 대해서 동해안에 위치한 영덕에서 약 3년 동안 폭로 실험을 수행하였다. 실험이 진행되는 동안, 철근의 부식 개시 시기를 추정하기 위하여 시험체에 대해서 자연전위 측정에 의한 부식 모니터링을 수행하였고, 철근부식이 감지되었을 때 시험체를 파괴한 후 콘크리트 중 염화물량을 평가함으로써 보다 합리적이고 신뢰적인 임계 염화물량을 제시하였다. 결국, 콘크리트 중 철근의 부식 임계 염화물량은 W/C비에 의존하며, 콘크리트 피복두께와는 거의 무관한 것으로 나타났다.

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복부농양진단을 위한 Indium-111 표지백혈구스캔 (Scintigraphy with Indium-111-oxine Labeled Leukocytes for Localization of Abscesses)

  • 김병태;이동수;이경수;최형식;김명준;양승오;이재훈;최창순;김택규;정준기;이명철;고창순
    • 대한핵의학회지
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    • 제24권1호
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    • pp.37-48
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    • 1990
  • Detection of deep-seated abscesses is sometimes difficult with ultrasonogrpahy or computed tome graphy alone. Indium-111-labeled leukocyte has widely used in the localization of abscesses after introduction by Segal and Thakur in 1976. But there are some difficulties in using indium-111-oxine in our country because of hardness to get the radiopharmaceutical timely and long time for labeling leukocytes. So we peformed the indium-111-labeled leukocyte scan for establishment of the labeling procedure and clinical application. We labeled the mixed leukocytes from 36 ml of patient's blood using 4 ml of ACD solution, 7 ml of 6% hydroxyethyl starch solution $(HESPAN^{(R)})$, 1 mCi of indium-111 oxine, 5 ml of normal saline and centrifuge. It took about 2 hours for the preparation of radiolabeled leukocytes and attention for contamination was needed. The average injected dose of labeled mixed leukocytes was 465 uCi. The average number of injected leukocytes was $2.5\times10^8$ and the labeling ratio was $57{\pm}13%$ (Table 2, Fig. 5). These number and ratio were sufficient for the localization of abscess. About twenty per cent of indium was labeled to red blood cells and platelets (Fig. 6) and the half-life of injected radiolabeled leukocytes was 8.3 hours. Scan was performed in 9 patients who were suspected to have abscesses clinically or radiologically. Three patients were positive, in one patient who had abscess close to lower lumbar vertebrae was surgically drained and another 2 positive cases did not show abscess clearly on computed tomography, so only antibiotics were administrated and treated successfully. The negative 6 patients were improved without specific treatment. In conclusion, the use of indium-111 oxine labeled leukocytes for localization of abscesses were very specific and helpful in the decision of treatment considering its relatively simple labeling method, and could be easily performed providing timely supply of the radiopharmaceutical.

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불안정한 생체징후 하의 두피 결출상 환자의 치험례 (Treatment of Complete Scalp Avulsion with the Conditions of Unstable Vital Signs: A Case Report)

  • 이강우;강상윤;양원용;범진식
    • 대한두개안면성형외과학회지
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    • 제12권2호
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    • pp.116-120
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    • 2011
  • Purpose: Scalp avulsion is a life-threatening injury that may cause trauma to the forehead, eyebrows, and periauricular tissue. It is difficult to treat scalp avulsion as it may lead to severe bleeding. Therefore, emergency scalp replantation surgery is necessary, and we must consider the function, aesthetics, and psychology of the patients. A case of scalp avulsion leading to massive bleeding was encountered by these authors, which led to a failure to achieve the proper operation conditions in an adequate time period. Methods: A 49-year-old female was hospitalized due to having had her head caught in a rotatory machine, causing complete scalp avulsion which included the dorsum of the nose, both eyebrows, and ears. Emergent microsurgical replantation was performed, where a superficial temporal artery and a vein were anastomosed, but the patient's vital signs were too unstable for further operation due to excessive blood loss. Three days after the microanastomosis, venous congestion developed at the replanted scalp, and a medicinal leech was used. Leech therapy resolved the venous congestion. A demarcation then developed between the vitalized scalp tissue and the necrotized area. Debridement was performed 2 times on the necrotized scalp area. Finally, split-thickness skin graft with a dermal acellular matrix ($Matriderm^{(R)}$) was performed on the defective areas, which included the left temporal area, the occipital area, and both eyebrows. Results: The forehead, vertex, right temporal area, and half of the occipital area were successfully replanted, and the hair at the replanted scalp was preserved. As stated above, two-thirds of the scalp survived; the patient could cover the skin graft area with her hair, and could wear a wig. Conclusion: Complete scalp avulsion needs emergent replantation with microsurgical revascularization, but it often leads to serious vital conditions. We report a case with acceptable results, although the microanastomosed vessel was minimal due to the patient's unstable vital signs.

Analysis of SCI Journals Cited by Korean Journals in the Computer field

  • Kim, Byungkyu;You, Beom-Jong;Kang, Ji-Hoon
    • 한국컴퓨터정보학회논문지
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    • 제24권11호
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    • pp.79-86
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    • 2019
  • 4차 산업혁명의 핵심 학문인 컴퓨터 분야에서 생산되는 연구성과물에 대한 활용 정보자원의 분석 및 제공은 매우 중요하다. 본 논문에서는 국내 컴퓨터분야 학술지 수록 논문들에서 인용한 국제과학기술인용색인인 SCI 학술지들을 식별하여 피인용 현황과 이들의 동시인용 관계를 네트워크로 생성하여 분석하고 지도화하여 시각화하는 연구를 수행하였다. 이를 위해 기반 데이터로 KSCD의 발행연도 기준 2015년부터 2017년까지의 논문 및 참고문헌 데이터를 활용하였고 학술지 동시인용 기법과 네트워크 중심성 분석기법을 사용하였다. 연구 수행 결과, 국내 컴퓨터 분야 학술지 논문들이 인용한 SCI 학술지 및 논문들의 피인용 순위와 인용나이 분석을 통한 인용절정기(2년), 인용반감기(6.6년), 즉시인용율(2.4%)이 파악되었다. 네트워크 중심성 분석결과 피인용 SCI 학술지들에 대한 연결정도, 사이, 근접중심성 지표가 측정되어 지표별 학술지 순위가 측정되었으며 네트워크의 지도화를 통한 시각화를 통해 피인용 SCI 학술지 간 주제분류 간의 관계성을 파악하였다.

만성두드러기에 대한 임상적 고찰 (Clinical study of Chronic Urticaria)

  • 김혜정
    • 한방안이비인후피부과학회지
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    • 제15권2호
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    • pp.252-260
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    • 2002
  • Introduction Urticaria is widely spread disease. About 15-20 $\%$ of population has experienced at least once in a life time. The etiology of urticaria is uncertain till now, and the affcting factors are various chemical material, physical factors, alcohol, fever, exercise, and hormone, etc. The symptoms of urticaria are small or large wheal-erythema reaction and itching or tingling sense. Cause there is no probe to detect the urticaria clearly, the treatment of urticaria is symptomatic. And mostly urticaria can be chronic and very hard to treat it fundamentally. Nowadays, many trials to treat the urticaria in oriental medical way show good curability. In this paper I'd like to report the treatment rate and degree of urticaria patients mostly using anti-histamine medication. Subjects From the outpatients who visited Korean Hospital of Kyunghee Kangnam during 2000-4 and 2002-1, the 36 chronic urticaria patients, at least more than 4 weeks from onset and 2weeks of treatment period, were chosen. Methods I evaluated the results of treatment with the following scale. Very Good: The all symptoms are clearly disappeared or one third of symptoms remain and sometimes eruption is appeared. Good: Half of the symptoms are improved but most of symptoms remain. No Change: No change appears before and after treatment. Worse: The degree and duration of eruption get worse than pre-treatment state. Results For Acupuncture treatment, I chose the several Acu points like Hapgok(합곡), Taichung(대충), Gokji(곡지), Yanggok(양곡), Yanggea(양계), and lmeup(족임읍), and usually lasted it 15 minutes. With the acupuncture treatment and herb medicine, 2-3 times a week, the patients whose treatment period was 2 to 4 weeks were 17(47.2$\%$), 4 to 8 weeks were 11(30.5$\%$), 8 to 12 weeks were 3(8.3$\%$), 12 to 16 weeks were 3(8.3$\%$), longer than 16 weeks were 2(5.5$\%$) Collecting the statistics of the frequency of prescripted herb medicine, Hyangsosan(향소산) was prescripted 21 times(58.3$\%$), Hyangsapyungwisan(향사평위산) was 15 times(41.6$\%$), Hwapisan(화피산) was 9 times(25$\%$), Yangwitang(양위탕) was 6 times(16.6$\%$), Bojungikkitang(보중익기탕가미) was 4 times(11.1$\%$), Yongdamsagantang (용담사간탕가미) was 4 times(11.1$\%$). The result of the treatments, evaluating with mentioned rate scale, was 11 cases(30.5$\%$) were Very Good degree, 19 cases(52.7$\%$) were Good , 6 cases(16.6$\%$) were No Change. No cases were Worse degree. Conclusion According to this research, we could say that chronic urticaria can be treated with Oriental medical methods. But more precise probes in both Oriental and Western medicine to diagnose the chronic urticaria should be established and we need to make standards for testing and diagnosing the chronic urticaria.

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중금속 안정화제의 반응 매개변수 결정 및 중금속 안정화 효율성 평가 (Determining Kinetic Parameters and Stabilization Efficiency of Heavy Metals with Various Chemical Amendment)

  • 오세진;김성철;김태희;연규훈;이진수;양재의
    • 한국토양비료학회지
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    • 제44권6호
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    • pp.1063-1070
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    • 2011
  • 본 연구는 수용액 내 존재하는 Cd, Pb을 다양한 화학적 안정화제를 이용하여 안정화 효율성을 평가하였다. 연구에 사용한 안정화제는 중금속 이온과의 반응특성 별로 석회물질, 광물질 등으로 구분하여 문헌조사를 바탕으로 5종을 선정하여 사용했다. 안정화 효율성 평가방법은 용액 내 중금속 함량을 단계적으로 제조하여 안정화 효율성, 반감기 및 반응속도 산정 및 반응 후 안정화제의 반응생성물 확인의 순으로 진행했다. 안정화 효율성 평가결과 석회물질 ($CaCO_3$)을 다량 함유하여 기본적으로 pH를 8이상으로 교정하는 안정화제의 경우 처리량에 상관없이 대부분 불용화되는 것으로 나타났으며, 낮은 산도교정 물질은 50% 수준의 효율성을 갖는 것으로 나타났다. 또한, 효율성이 크게 나타난 물질을 대상으로 반응속도상수 (K)를 산출한 결과 Cd의 경우 처리량에 따라 증가하였지만, Pb의 경우 초기에 반응속도가 빠르게 일어나 처리량에 따른 평가는 불가능 하였다. 다량의 중금속 이온과 반응시킨 안정화제의 표면관찰을 통한 생성물 검정 결과 SEM 사진으로 반응 전 후의 생성물 확인을 간접적으로 확인하였다. 또한, SEM-EDS 분석결과 반응 후 물질 표면에서 Cd과 Pb의 성분 검출을 확인하였다. 그리고 XRD 분석을 통해 효율성이 좋았던 물질에서 Cd과 Pb 성분의 검출이 확인되어 수용액 상에 이온형태로 존재하는 중금속의 복원에 안정화제를 이용한 저감은 효율적일 것으로 판단된다.

개에서 피모벤단-펜톡시필린 분말 제형 합제의 경구투여시 약물약동학 및 약물약력학에 대한 연구 (Pharmacokinetics and Pharmacodynamics Following Oral Administration of Pimobendan-Pentoxifylline Powder Formulation Mixture in Dogs)

  • 노웅빈;송두원;강여림;박유진;유초롱;이종호;김기훈;정상희;강민희
    • 한국임상수의학회지
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    • 제36권1호
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    • pp.46-52
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    • 2019
  • Pimobendan has inotropic and vasodilating effects on cardiovascular system, and pentoxifylline is known to decrease blood viscosity and improve blood flow to the heart. This study investigated the pharmacokinetics and pharmacodynamics following oral administration of pimobendan-pentoxifylline powder mixture in dogs. Eight healthy dogs were included and were divided into control (n = 4) and experimental (n = 4) groups. Vehicle powder and pimobendan-pentoxifylline powder mixture (pimobendane 0.25 mg/kg, pentoxifylline 15 mg/kg) were administrated orally to control and experimental groups, respectively. Plasma samples and measurement of echocardiographic indices were obtained for 24 hours following administration. Pimobendan and pentoxifylline concentrations were investigated using liquid chromatography-mass spectrometer (LC-MS) assay. The elimination half-life ($T_{1/2}$) were $2.65{\pm}1.42hours$ for pimobendan and $0.29{\pm}0.23hours$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $1.08{\pm}0.72hours$ for pimobendan and $0.29{\pm}0.14hours$ for pentoxifylline. The maximum blood concentration ($C_{max}$) were $2.83{\pm}1.50ng/mL$ for pimobendan and $1184.33{\pm}932.37ng/mL$ for pentoxifylline. Among echocardiographic indices, fractional shortening (FS), left ventricular internal diameter at end systole (LVIDs), and pre-ejection period (PEP) showed significant changes at 1-4 hours after the administration of pimobendan-pentoxifylline powder mixture. No adverse effects were observed during the investigation. This study demonstrates that pimobendan-pentoxifylline powder mixture can be used to control cardiovascular diseases in dogs.