• 제목/요약/키워드: low dose effect

검색결과 1,028건 처리시간 0.026초

감마선 조사가 저염 명란(Theragra chalcogramma) 젓갈의 품질에 미치는 영향 (Effects of Gamma Irradiation on Quality Characteristics of Low-salt Fermented Pollack Theragra chalcogramma Roe)

  • 남기호;이현진;박노현;김동환;송민규;김종일;오광수
    • 한국수산과학회지
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    • 제55권3호
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    • pp.302-309
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    • 2022
  • Low-salt fermented pollack Theragra chalcogramma roe (Myungran Jeotgal, MJ), a traditional Korean fermented seafood, was prepared using a commercially available method and irradiated using gamma rays (0-10.0 kGy) to investigate the effect of gamma irradiation (GI) on food quality. After irradiation with 2.5 kGy gamma rays, the number of viable cells in MJ was reduced by one log compared to that observed in non-irradiated MJ, and no living cells were detected after 7.5 kGy GI. Though up to 2.5 kGy GI had no effect on color quality, over 7.5 kGy GI resulted in significantly poor quality MJ surface color. Saturated fatty acid contents increased slightly in irradiated MJ, while those of polyenes and monoenes decreased slightly as the GI dose increased. Exposure of MJ to GI had no effect on the free amino acid and mineral composition. These results demonstrated that the appropriate GI dose for MJ ranged from 2.5 to 5.0 kGy, which may be recommended for industrial application.

Inhibitory Effect of Lichen Metabolites and their Synthetic Analogues on Melanin Biosynthesis in Cultured B-16 Mouse Melanoma Cells

  • Matubara, H.;Miharu, K.;Kinoshita, K.;Koyama, K.;Ye, Yang;Takahashi, K.;Yoshimura, I.;Yamamoto, Y.;Miura, Y.;Kinoshita, Y.
    • Natural Product Sciences
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    • 제4권3호
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    • pp.161-169
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    • 1998
  • The analogues of lichen components showing anti-tyrosinase activities were synthesized. 4-Alkylresorcinol derivatives showed both the inhibitory activity and cytotoxicity in B-16 melanoma cells at the doses of 10 mM to 1.2 mM. Resorcinol and 4-methylresorcinol showed the inhibitory effect with a low cytotoxicity at the doses of 2.5 mM and $600\;{\mu}M$ among 4-alkylresorcinols, respectively. Some diphenylmethane derivatives (Type A, B, and C) had strong activities with a low cytotoxicity. While xanthine derivatives had no effect. Glucosides of 4,5-alkylresorcinol and the diphenylmethane derivative (Type B) were prepared to decrease the cytotoxicity. As a result, no effect were observed. Liposome of the diphenylmethane derivative (Type B) was prepared for the same purpose, and the latter showed a remarkable effect at the dose of $15\;{\mu}M$ with a low cytotoxicity.

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다목적 방사선 조사장치 개발 및 선량분포특성 (The Development of a Multi-Purpose Irradiator and the Characteristic of Dose Distribution)

  • 이동훈;지영훈;이동한;김윤종;홍승홍
    • 전자공학회논문지SC
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    • 제39권6호
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    • pp.42-48
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    • 2002
  • 다목적 방사선 조사장치의 설계, 제작 및 성능검사에 대해 기술하였다. 세슘-137을 사용한 다목적 방사선조사장치는 생물학에서 저선량 방사선에 대한 영향연구, 혹은 TLD(Thermo Luminescent dosimeter)의 교정을 위해 사용되어진다. 본 조사장치는 방사선 동위원소를 안전한곳에 저장하고 있다가 방사선조사시에만 조사실로 180도 회전하여 설정된 시간만큼 시료에 방사선 조사가 이루어 진 후, 사용이 끝나면 다시 차폐된 저장위치로 복귀하게된다. 제어시스템은 PLC 기반으로 구축하여 저선량율 조사장치의 시제품을 제작하였으며, 또한 컴퓨터를 통해 방사선 조사장치의 제어 및 세부 동작 상태 등을 실시간 검색, 원격제어 및 관리 할 수 있는 종합 관리 프로그램을 개발하였다. 조사실 내부 구성은 시료의 종류에 따라 최대 20RPM까지 다양하게 회전하면서 균일 조사될 수 있도록 조사실 및 챔버를 설계 제작하였으며, 조사실내 넣을 수 있는 조사체 최대 용량은 4.5리터이다. 조사실내의 방사선량의 분포도는 가프크로믹 필름을 사용하여 측정한 결과 2Ci 범위내에서 세슘-137의 경우 공기중에서 0.13cGy/min이었고 일반 물질과 등가인 물에서는 0.11cGy/min로 나타났으며, 오차는 약 ${\pm}$7%의 한도내에서 균일한 분포를 보였다. 또한 실제 누설선량은 조사실 밖 표면에서 최대 0.35mR/hr이였으며 1m 떨어진곳에서는 최대 0.03mR/hr로 허용치 이내였다.

L-NAME에 의한 쥐의 발바닥에서 Freund's Complete Adjuvant에 의해 유발된 통증 억제 (L-NAME Inhibits Hyperalgesia Induced by Freund's Complete Adjuvant in Rat Paw)

  • 이청;최윤;송명희;임중우;이동명
    • The Korean Journal of Pain
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    • 제11권2호
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    • pp.194-200
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    • 1998
  • Background: Effect of nitric oxide on the hyperalgesia induced by inflammation is controversial. We attempted to find out the peripheral effects of nitric oxide (NO) on hyperalgesia induced by Freund's complete adjuvant (FCA) induced inflammation. Methods: Male Sprague Dawley rats were divided into three groups; control, low dose NG-nitro-L-arginine methyl ester (L-NAME, 500 ug), high dose L-NAME (5 mg). Inflammation was induced by injecting 0.1 ml of FCA intraplantarly, which shows typical hyperalgesia within twelve hours after injection and maintained for about one week. Drugs were injected 2 hours before, just before, and 3, 6, 9, 12 hours after the injection of FCA. Effect of L-NAME on hyperalgesia was assessed by measuring mechanical hyperalgesia and spontaneous pain for 3 days. Results: When injected at the site of inflammation, L-NAME caused dose dependent reduction of spontaneous hyperalgesia. Mechanical hyperalgesia was also reduced by high dose L-NAME (p<0.05). After systemic injection of high dose L-NAME in the back, no significant difference was noticed. Conclusions: This suggest that L-NAME reduces FCA induced hyperalgesia via peripheral action.

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대황산(大黃酸)의 당뇨병쥐 신장조직섬유화 억제 효과에 관한 실험연구 (Inhibitory Effect of Rhein on Renal Fibrosis in Diabetic Nephropathy Rats)

  • 조용걸;조정림;장걸;류홍봉;최영군;김상찬;김선형
    • 대한한의학방제학회지
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    • 제21권1호
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    • pp.154-160
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    • 2013
  • Objectives : To investigate the therapeutic effect and underlying mechanisms of rhein on renal fibrosis in diabetic rats. Methods : Diabetic nephropathy (DN) was induced in adult Wistar rats via introperitoneal injection of streptozotocin (STZ) (20 mg/kg/d) for three consecutive days. Two days after the last dose of STZ, rhein was administered to the diabetic rats at a dose of 25 mg/kg or 50 mg/kg, twice a day by gavage, respectively. Following 28 days treatment with rhein, the plasma glucose and creatinine levels were measured, the renal levels of TGF-${\beta}1$ protein and mRNA were examined, and the fibronectin mRNA levels were also determined. Results : Rhein significantly inhibited the increased plasma glucose and creatinine levels of diabetic rats in a dose- and a time-dependent way. Immunohistochemical analysis showed both doses of rhein markedly attenuated elevated induction of renal TGF-${\beta}1$ protein expressions in diabetic rats. Additionally, the high dose of rhein improved both TGF-${\beta}1$ and fibronectin mRNA expressions, while the low dose of rhein only alleviated fibronectin mRNA expressions. Conclusions : Rhein can improve renal fibrosis in diabetic nephropathy rats, and which may be mediated through inhibition of the renal mRNA expressions of TGF-${\beta}1$ and fibronectin.

방사선 치료 시 차폐물질 사용에 따른 kV-CBCT 선량감소 효과 (Reduced Effect of kV-CBCT Dose by Use of Shielding Materials in Radiation Therapy)

  • 조현종;박은태;김정훈
    • 한국방사선학회논문지
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    • 제12권4호
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    • pp.467-474
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    • 2018
  • CBCT는 치료부위의 정확도 향상에 유용하지만, 반복적인 사용으로 피폭선량이 높아지는 단점이 있다. 이에 본 연구에서는 차폐체를 사용한 모의실험과 선량감소 효과를 데이터화하여 CBCT 시행 시 선량 저감화를 위한 기초자료를 제공하고자 한다. 본 연구에서는 MCNPX를 통해 CBCT를 모사하여 광자선을 분석한 후, UF-revised 인체 모의 피폭체를 대상으로 흉복부 촬영 시 장기의 흡수선량을 계산하였다. 이 때, 차폐체(납, 안티몬, 황산바륨, 텅스텐, 비스무스) 유무와 차폐 재질에 따른 장기선량을 평가하였다. 차폐를 하지 않고 CBCT 촬영을 하였을 경우 유방 과 척추에서 선량이 높게 계산되었으며, 식도와 폐에서 선량이 낮게 계산되었다. 차폐체 재질에 따른 선량 은 황산바륨, 안티몬, 비스무스, 납, 텅스텐 순으로 선량이 높게 계산되었다. 차폐체 유무에 따른 선량 감소율을 평가해 보면 흉선(73.6%), 유방(59.9%)에서 가장 차폐율이 높고, 폐(2.1%), 척추(12.6%)에서 가장 낮은 차폐율을 보였다.

붕소-중성자 포획치료를 위한 미세 속중성자 선량 특성 연구 (Dosimetry of the Low Fluence Fast Neutron Beams for Boron Neutron Capture Therapy)

  • 이동한;지영훈;이동훈;박현주;이석;이경후;서소희;김미숙;조철구;류성렬;유형준;곽호신;이창훈
    • Radiation Oncology Journal
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    • 제19권1호
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    • pp.66-73
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    • 2001
  • 목적 : 붕소-중성자 포획치료법(Boron Neutron Capture Therapy, BNCT)을 위해 원자력병원 싸이클로트론에서 발생되는 최대에너지 34.4 MeV의 속중성자(Fast neutron)를 70 cm 파라핀으로 감속시킨 후 선량 특성을 조사하였다. 그 결과를 토대로 열외중성자(Epithermal neutron) 선량 측정법에 대한 프로토콜을 확립하여 원자로에서 방출되는 열외 중성자 선량 특성 평가의 기초를 삼고, 가속기를 이용한 BNCT 연구에 대한 타당성 여부를 조사하고자 한다. 대상 및 방법 : 공기 중 선량 및 물질 내 선량 분포 측정을 위해 Unidos 10005 (PTW, Germany) 전기계와 조직 등가 물질인 A-150 플라스틱으로 제작된 IC-17 (Far West, USA) 및 IC-18, ElC-1 이온함을 사용하였고, 감마선의 측정을 위해서는 마그네슘으로 제작된 IC-l7M 이온함을 이용하였으며 조직등가 기체와 아르곤 기체를 분당 5cc 씩 주입하며 측정하였다. 중성자, 광자, 전자가 혼합된 장의 모의 수송 해석을 위해 이용되는 Monte Carlo N-Particle (MCNP) transport code를 사용하여 2차원적 선량 분포 및 에너지 분포를 계산하였으며 이 결과를 측정값과 비교하였다. 결과 : BNCT에서의 유효 치료 깊이인 물 팬텀 4 cm에서의 선량은 치료기 1 MU 당 $6.47\times10^{-3}\;cGy$로 미세하였으며, 이때 감마 오염도(contamination)는 $65.2{\pm}0.9\%$로 중성자보다는 감마선에 의한 선량 기여분이 우세하였다. 깊이에 따른 선량 분포 특성에서는 중성자 선량은 선형적으로 감쇠 되었고, 감마선량은 지수적으로 보다 급격히 감쇠되는 경향을 보였으며 전체 선량의 $D_{20}/D_{10}$은 0.718 이었다. MCNP에 의한 에너지 분포 전산 계산의 결과 2.87 MeV 이하에서 중성자 피크가 나타났으며, 저에너지 영역에서는 감마선이 연속적으로 분포되는 양상을 보였다. 결론 : 벽 물질이 서로 다른 두 개의 이온함을 사용한 직접 선량 측정과 MCNP 전산 시뮬레이션을 이용한 공간 선량분포 계산으로 미세 속중성자 빔에 대한 선량 특성을 파악할 수 있었으며, 원자로 열외중성자 주(Epithermal neutron column)에 대한 선량 평가 자료로 확보하였다. 아울러 가속기에 대한 연구가 진행되어 고전압, 고전류를 발생시키는 전원 공급장치와 표적핵(Target) 물질이 개발되고 비스무스나 납 등에 의해 감마 오염도를 줄일 경우, 싸이크로트론에 의한 보론-중성자 포획치료도 가능해질 것으로 판단된다.

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마우스 동종 조혈모세포 이식모델에서 Cyclosporin A, FK506, 3-Deazaadenosine 등의 약제가 급성 이식편대 숙주병과 생존에 미치는 영향 (Effects of Cyclosporin A, FK506, and 3-Deazaadenosine on Acute Graft-versus-host Disease and Survival in Allogeneic Murine Hematopoietic Stem Cell Transplantation)

  • 진종률;정대철;엄현석;정낙균;박수정;최병옥;민우성;김학기;김춘추;한치화
    • IMMUNE NETWORK
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    • 제3권2호
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    • pp.150-155
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    • 2003
  • Background: We investigated the effect of donor marrow T cell depletion, administration of FK506, cyclosporin A (CSA), and 3-deazaadenosine (DZA) on graft versus host disease (GVHD) after allogeneic murine hematopoietic stem cell transplantation (HSCT). Methods: We used 4 to 6 week old Balb/c ($H-2^d$, recipient), and C3H/He ($H-2^k$, donor) mice. Total body irradiated recipients received $1{\times}10^7$ bone marrow cells (BM) and $0.5{\times}10^7$ splenocytes of donor under FK506 (36 mg/kg/day), CSA (5 mg/kg/day, 20 mg/kg/day), and DZA (45 mg/kg/day), which were injected intraperitoneally from day 1 to day 14 daily and then three times a week for another 2 weeks. To prevent the GVHD, irradiated Balb/c mice were transplanted with $1{\times}10^7$ rotor-off (R/O) cells of donor BM. The severity of GVHD was assessed daily by clinical scoring method. Results: All experimental groups were well grafted after HSCT. Mice in experimental group showed higher GVHD score and more rapid progression of GVHD than the mice with R/O cells (R/O group) (p<0.01). There were relatively low GVHD scores and slow progressions in FK506 and low dose CSAgroups than high dose CSA group (p<0.01). The survival was better in FK506 group than low dose CSA group. All mice treated with CSA died within 12 days after HSCT. The GVHD score in DZA group was low and slow in comparison with control group (p<0.05), but severity and progression were similar with low dose CSA group (p=0.11). All mice without immunosuppressive treatment died within 8 days, but all survived in R/O group (p<0.01). Survival in low dose CSA group was longer than in control group (p<0.05), but in high dose CSA group, survival was similar to control group. The survival benefit in DZA group was similar with low dose CSA group. FK506 group has the best survival benefit than other groups (p<0.01), comparable with R/O group (p=0.18), although probability of survival was 60%. Conclusion: We developed lethal GVHD model after allogeneic murine HSCT. In this model, immunosuppressive agents showed survival benefits in prevention of GVHD. DZA showed similar survival benefits to low dose CSA. We propose that DZA can be used as a new immunosuppressive agent to prevent GVHD after allogeneic HSCT.

감마선 이용 저염 오징어젓갈 제조시 정미성분의 변화 (Effects of Gamma Irradiation on Taste Compounds in Processing of Low Salted and Fermented Squid)

  • 변명우;이경행;김재훈;이주운;이은미;김영지
    • 한국식품영양과학회지
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    • 제28권5호
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    • pp.1051-1057
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    • 1999
  • The effects of gamma irradiation on taste compounds of low salted and fermented squid were investig ated. Salted and fermented squid products were prepared with salt concentrations of 5%, 10%, and 20% and was fermented at 15oC and 25oC after gamma irradiation with a dosage of 2.5~10 kGy. Amino nitrogen (AN), volatile basic nitrogen(VBN), trimethylamine(TMA), and hypoxanthine(Hx) contents were examined during the fermentation periods. Results showed that gamma irradiation had no effect on the initial con tents of AN, VBN, TMA, and Hx compared with non irradiated salted and fermented squid. During the fermentation periods, these contents rapidly increased in accordance with the decrease in NaCl concen tration and irradiation dose, and the increase in fermentation temperature. Specifically, the taste compounds of salted and fermented squid prepared with a NaCl concentration of 10% and an irradiation dose of 10 kGy maintained the appropriate level for the fermentation period at 15oC.

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저농도 만성적인 유기용제 폭로시 자각증상과 Flicker 검사치와의 연관성 (Subjective Symptoms and Flicker Test Vlaues in Relation to Chronic Low Dose Organic Solvent Exposure)

  • 손명호;손석준;최진수
    • Journal of Preventive Medicine and Public Health
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    • 제27권3호
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    • pp.557-567
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    • 1994
  • This study was conducted to examine the effect of chronic low dose organic solvent exposures in the industries towards then neurobehavioral functions of workers. Subjective symptoms on neurobehavioral function as well as a visual reaction time test (Flicker test) were administered to 94 exposed and 162 unexposed workers in a oil refinery and some other auto-repair shops. The results obtained were as follows : 1. Symptom complaints were higher and Flicker test values were lower in exposed workers than in unexposed workers. 2. Flicker valus were Inversely correlated with urinary Hippuric acid concentration in exposed workers(r=-0.26, p<0.05). 3. Flicker valus were inversely co..elated with Subjective symptom score(r=-0.15, p<0.05). Low Flicker value were also related with some subjetive symptoms such as 'Dimmed vision', 'Nightmare', 'Weakness on extrimity' in workers as a whole. While symptoms of 'Dimmed vision ', 'Nightmare' only observed among exposed workers.

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