• 제목/요약/키워드: Nuclear Sites

검색결과 429건 처리시간 0.027초

In Situ Gamma-ray Spectrometry Using an LaBr3(Ce) Scintillation Detector

  • Ji, Young-Yong;Lim, Taehyung;Lee, Wanno
    • Journal of Radiation Protection and Research
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    • 제43권3호
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    • pp.85-96
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    • 2018
  • Background: A variety of inorganic scintillators have been developed and improved for use in radiation detection and measurement, and in situ gamma-ray spectrometry in the environment remains an important area in nuclear safety. In order to verify the feasibility of promising scintillators in an actual environment, a performance test is necessary to identify gamma-ray peaks and calculate the radioactivity from their net count rates in peaks. Materials and Methods: Among commercially available scintillators, $LaBr_3(Ce)$ scintillators have so far shown the highest energy resolution when detecting and identifying gamma-rays. However, the intrinsic background of this scintillator type affects efficient application to the environment with a relatively low count rate. An algorithm to subtract the intrinsic background was consequently developed, and the in situ calibration factor at 1 m above ground level was calculated from Monte Carlo simulation in order to determine the radioactivity from the measured net count rate. Results and Discussion: The radioactivity of six natural radionuclides in the environment was evaluated from in situ gamma-ray spectrometry using an $LaBr_3(Ce)$ detector. The results were then compared with those of a portable high purity Ge (HPGe) detector with in situ object counting system (ISOCS) software at the same sites. In addition, the radioactive cesium in the ground of Jeju Island, South Korea, was determined with the same assumption of the source distribution between measurements using two detectors. Conclusion: Good agreement between both detectors was achieved in the in situ gamma-ray spectrometry of natural as well as artificial radionuclides in the ground. This means that an $LaBr_3(Ce)$ detector can produce reliable and stable results of radioactivity in the ground from the measured energy spectrum of incident gamma-rays at 1 m above the ground.

Development of Polymeric Nanopaclitaxel and Comparison with Free Paclitaxel for Effects on Cell Proliferation of MCF-7 and B16F0 Carcinoma Cells

  • Yadav, Deepak;Anwar, Mohammad Faiyaz;Garg, Veena;Kardam, Hemant;Beg, Mohd Nadeem;Suri, Suruchi;Gaur, Sikha;Asif, Mohd
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.2335-2340
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    • 2014
  • Paclitaxel is hydrophobic in nature and is recognized as a highly toxic anticancer drug, showing adverse effects in normal body sites. In this study, we developed a polymeric nano drug carrier for safe delivery of the paclitaxel to the cancer that releases the drug in a sustained manner and reduces side effects. N-isopropylacrylamide/vinyl pyrrolidone (NIPAAm/VP) nanoparticles were synthesized by radical polymerization. Physicochemical characterization of the polymeric nanoparticles was conducted using dynamic light scattering, transmission electron microscopy, scanning electron microscopy and nuclear magnetic resonance, which confirmedpolymerization of formulated nanoparticles. Drug release was assessed using a spectrophotometer and cell viability assays were carried out on the MCF-7 breast cancer and B16F0 skin cancer cell lines. NIPAAm/VP nanoparticles demonstrated a size distribution in the 65-108 nm range and surface charge measured -15.4 mV. SEM showed the nanoparticles to be spherical in shape with a slow drug release of ~70% in PBS at $38^{\circ}C$ over 96 h. Drug loaded nanoparticles were associated with increased viability of MCF-7 and B16F0 cells in comparison to free paclitaxel. Nano loaded paclitaxel shows high therapeutic efficiency by sustained release action for the longer period of time, i increasing its efficacy and biocompatibility for human cancer therapy. Therefore, paclitaxel loaded (NIPAAm/VP) nanoparticles may provide opportunities to expand delivery of the drug for clinical selection.

The relationship between the variants in the 5'-untranslated regions of equine chorionic gonadotropin genes and serum equine chorionic gonadotropin levels

  • Liu, ShuQin;Lian, Song;Yang, YunZhou;Fu, ChunZheng;Ma, HongYing;Xiong, ZhiYao;Ling, Yao;Zhao, ChunJiang
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권12호
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    • pp.1679-1683
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    • 2017
  • Objective: An experiment was conducted to study the association between the single nucleotide polymorphisms (SNPs) in 5'-untranslated regions (5'-UTR) of equine chorionic gonadotropin (eCG) genes and the serum eCG levels. Methods: SNPs in 5'-UTR of eCG genes were screened across 10 horse breeds, including 7 Chinese indigenous breeds and 3 imported breeds using iPLEX chemistry, and the association between the serum eCG levels of 174 pregnant Da'an mares and their serum eCG levels (determined with ELISA) was analyzed. Results: Four SNPs were identified in the 5'-UTR of the $eCG{\alpha}$ gene, and one of them was unique in the indigenous breeds. There were 2 SNPs detected at the 5' end of the $eCG{\beta}$ subunit gene, and one of them was only found in the Chinese breeds. The SNP g.39948246T>C at the 5'-UTR of $eCG{\alpha}$ was associated significantly with eCG levels of 75-day pregnant mare serum (p<0.05) in Da'an mares. Prediction analysis on binding sites of transcription factors showed that the g.39948246T>C mutation causes appearance of the specific binding site of hepatocyte nuclear factor 3 forkhead homolog 2 (HFH-2), which is a transcriptional repressor belonging to the forkhead protein family of transcription factors. Conclusion: The SNP g.39948246T>C at the 5'-UTR of $eCG{\alpha}$ is associated with eCG levels of 75-day pregnant mare serum (p<0.05).

우측폐 중엽에 발생한 원발성 악성 흑색종 - 수술 치험 1예 - (Primary Malignant Melanoma of the Lung - 1 case report -)

  • 김동원
    • Journal of Chest Surgery
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    • 제36권4호
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    • pp.289-292
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    • 2003
  • 폐에 발생하는 원발성 악성 흑색종은 매우 드문 종양으로 문헌상으로 수 십 예의 결과만 보고되고 있다. 본 저자는 우측폐중엽에 발생한 원발성 악성 흑색종 1예를 치험하였는데 환자는 65세 된 남자로 객담을 동반한 기침으로 내원하여 컴퓨터단층촬영 소견상 우측폐 중엽에 종괴가 관찰되었으며 경피적 폐생검상 악성 흑색종이 확인되었고 bone scan상전이 소견은 없었으며 피부 및 안구 검사상 전이의 증거가 없었다. 환자는 원발성 악성 흑색종으로 진단하고 우측폐 중엽 절제술을 시행하였는데 약 4.5$\times$3 cm의 종괴가 우측폐 중엽에서 관찰되었으며 주변의 임파절을 함께 박리 하였다. 수술 중 특이 소견은 없었으며 수술 3일째 흉관을 제거할 수 있었고 병리조직 검사상 기관지 주변부의 임파절 전이가 확인되어 보조적 방사선 치료를 기획하고 수술 10일째 퇴원하였다. 환자는 현재 24개월째 외래를 통해 추적관찰 중인데 재발 및 전이의 증거 없이 지내고 있다.

림프절에 발생한 랑게르한스 세포 조직구증의 세침흡인 세포소견 -1예 보고- (Fine Needle Aspiration Cytology of Langerhans Cell Histiocytosis in a Lymph Node - A Case Report -)

  • 김민정;김교영;조현이;정동해;김나래;하승연
    • 대한세포병리학회지
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    • 제18권1호
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    • pp.87-91
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    • 2007
  • Langerhans cell histiocytosis (LCH) is a pleomorphic disease entity characterized by local or disseminated atypical Langerhans cells (LCs) found most commonly in bone, lungs, mucocutaneous structures and endocrine organs. Among different sites, unifocal disease confined to a lymph node (LN) is rare. We report a case of LCH confined to a LN in a 38-year-old male who presented with a 2 cm-sized cervical mass. The fine needle aspiration (FNA) smears of cervical LN showed high cellularity having isolated LCs with contorted nuclei and nuclear grooves mixed in multinucleated giant cells, small lymphocytes and eosinophils. Charcot-Leyden crystals were also seen, as were a few dendritic-like cells and intranuclear inclusions. Confirmation of LCH was made by histopathologic studies, positive reactions for S-100 protein and CD1a immunohistochemical staining and by the demonstration of Birbeck granules on electron microscopy. The differentials to be considered include dermatopathic lymphadenitis, sinus histiocytosis with massive lymphadenopathy, Hodgkin's lymphoma and malignant histiocytosis. The characteristic cytomorphologic pattern of LCH in a LN FNA smear plays an important role in suggesting the diagnosis of LCH.

Genome-Wide Analysis Identifies NURR1-Controlled Network of New Synapse Formation and Cell Cycle Arrest in Human Neural Stem Cells

  • Kim, Soo Min;Cho, Soo Young;Kim, Min Woong;Roh, Seung Ryul;Shin, Hee Sun;Suh, Young Ho;Geum, Dongho;Lee, Myung Ae
    • Molecules and Cells
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    • 제43권6호
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    • pp.551-571
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    • 2020
  • Nuclear receptor-related 1 (Nurr1) protein has been identified as an obligatory transcription factor in midbrain dopaminergic neurogenesis, but the global set of human NURR1 target genes remains unexplored. Here, we identified direct gene targets of NURR1 by analyzing genome-wide differential expression of NURR1 together with NURR1 consensus sites in three human neural stem cell (hNSC) lines. Microarray data were validated by quantitative PCR in hNSCs and mouse embryonic brains and through comparison to published human data, including genome-wide association study hits and the BioGPS gene expression atlas. Our analysis identified ~40 NURR1 direct target genes, many of them involved in essential protein modules such as synapse formation, neuronal cell migration during brain development, and cell cycle progression and DNA replication. Specifically, expression of genes related to synapse formation and neuronal cell migration correlated tightly with NURR1 expression, whereas cell cycle progression correlated negatively with it, precisely recapitulating midbrain dopaminergic development. Overall, this systematic examination of NURR1-controlled regulatory networks provides important insights into this protein's biological functions in dopamine-based neurogenesis.

Diclofenac Inhibits $IFN-{\gamma}$ Plus Lipopolysaccharide-Induced iNOS Gene Expression via Suppression of $NF-{\kappa}B$ Activation in RAW 264.7 Macrophages

  • Bae, So-Hyun;Ryu, Young-Sue;Hong, Jang-Hee;Park, Jin-Chan;Kim, Yong-Man;Seok, Jeong-Ho;Lee, Jae-Heun;Hur, Gang-Min
    • The Korean Journal of Physiology and Pharmacology
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    • 제5권6호
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    • pp.521-527
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    • 2001
  • Diclofenac, a phenylacetic acid derivative, is a widely used non-steroidal anti-inflammatory drug (NSAID) to provide effective relief of inflammation and pain. Nitric oxide (NO) synthesized by inducible nitric oxide synthase (iNOS) has been implicated as a mediator of inflammation. We examined the inhibitory effects of diclofenac on the induction of iNOS in RAW 264.7 macrophages which were activated with lipopolysaccharide (LPS) plus interferon-gamma $(IFN-{\gamma}).$ Treatment of RAW 264.7 cells with diclofenac and other NSAIDs (aspirin and indomethacin) significantly inhibited NO production and iNOS protein expression induced by LPS plus $IFN-{\gamma}.$ Also, diclofenac but not aspirin and indomethacin, inhibited iNOS mRNA expression and nuclear factor-kappa B $(NF-{\kappa}B)$ binding activity concentration-dependently. Furthermore, transfection of RAW 264.7 cells with iNOS promoter linked to a CAT reporter gene revealed that only diclofenac inhibited the iNOS promoter activity induced by LPS plus $IFN-{\gamma}$ through the $NF-{\kappa}B$ sites of iNOS promoter. Taken together, these suggest that diclofenac may exert its anti-inflammatory effect by inhibiting iNOS gene expression at the transcriptional level through suppression of $NF-{\kappa}B$ activation.

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방사선 비상계획구역에서의 일시거주자의 사회행동 특성 분석 (An Analysis of the Transient's Social Behavior in the Radiological Emergency Planning Zone)

  • 방선영;이갑복;정양근;이재은
    • Journal of Radiation Protection and Research
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    • 제32권2호
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    • pp.71-78
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    • 2007
  • 본 연구에서는 원자력 발전소 주변 일시거주자의 방사선 비상시 소개와 관련된 사회행동 특성-특히 소개와 관련된 행동특성을 분석하는데 목적이 있다. 이를 위해 먼저, 이론적 검토 차원에서 비상사태시 소개의 의미와 유형, 그리고 소개를 시작하는데 소요되는 소개준비시간을 살펴보았다. 그리고 소개 대상 주민에 대한 행동특성을 울진, 월성 및 고리원전 방사선비상계획 구역 내에 체류하는 일시거주자를 대상으로 면접설문조사를 통해 실증 분석하였다. 연구의 주요 결과는 다음과 같다. 첫째, 방사선 비상시의 원활한 소개 및 안전 확보를 위하여 일시 거주자에게 소개 경보에 대한 사전 지식을 효율적으로 제공하기 위한 방안을 마련하는 것이 필요하다. 둘째, 방사선 비상시 일시거주자의 교육 훈련 방안을 마련하는 것이 필요하다. 셋째, 일시거주자가 자발적 소개를 하지 않으려는 이유와 배경을 파악하고, 대응 방안을 마련하는 것이 필요하다.

The bactericidal effect of an atmospheric-pressure plasma jet on Porphyromonas gingivalis biofilms on sandblasted and acid-etched titanium discs

  • Lee, Ji-Yoon;Kim, Kyoung-Hwa;Park, Shin-Young;Yoon, Sung-Young;Kim, Gon-Ho;Lee, Yong-Moo;Rhyu, In-Chul;Seol, Yang-Jo
    • Journal of Periodontal and Implant Science
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    • 제49권5호
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    • pp.319-329
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    • 2019
  • Purpose: Direct application of atmospheric-pressure plasma jets (APPJs) has been established as an effective method of microbial decontamination. This study aimed to investigate the bactericidal effect of direct application of an APPJ using helium gas (He-APPJ) on Porphyromonas gingivalis biofilms on sandblasted and acid-etched (SLA) titanium discs. Methods: On the SLA discs covered by P. gingivalis biofilms, an APPJ with helium (He) as a discharge gas was applied at 3 different time intervals (0, 3, and 5 minutes). To evaluate the effect of the plasma itself, the He gas-only group was used as the control group. The bactericidal effect of the He-APPJ was determined by the number of colony-forming units. Bacterial viability was observed by confocal laser scanning microscopy (CLSM), and bacterial morphology was examined by scanning electron microscopy (SEM). Results: As the plasma treatment time increased, the amount of P. gingivalis decreased, and the difference was statistically significant. In the SEM images, compared to the control group, the bacterial biofilm structure on SLA discs treated by the He-APPJ for more than 3 minutes was destroyed. In addition, the CLSM images showed consistent results. Even in sites distant from the area of direct He-APPJ exposure, decontamination effects were observed in both SEM and CLSM images. Conclusions: He-APPJ application was effective in removing P. gingivalis biofilm on SLA titanium discs in an in vitro experiment.

롤 컴팩션을 이용한 분말 방사성폐기물의 펠렛화 연구 (A Study on the Pelletization of Powdered Radioactive Waste by Roll Compaction)

  • 송종순;임상현;정민영;김기홍
    • 방사성폐기물학회지
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    • 제17권2호
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    • pp.203-212
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    • 2019
  • 처분 부적합 폐기물이란 원전운영이나 해체 시 처리, 고화 및 포장이 요구되는 방사성폐기물 등을 일컬으며, 대표적으로 분산 특성을 갖는 입자성 방사성폐기물을 예로 들 수가 있다. 이들 폐기물에는 원전 운영과정에서 발생되는 농축폐액의 건조분말, 슬러리 및 슬러지, 향후 원전 해체과정에서 발생되는 온갖 분말 상태의 폐기물(콘크리트 파쇄물, 제염 슬러지 등), 그리고 제염이 용이치 못한 미세 크기의 방사능오염 토양 등이 있다. 입자성 폐기물을 기존의 고화방식으로 처리할 경우에는 최종 폐기물의 부피가 증가하는 단점을 갖게 되어 처분 비용의 증가 및 처분장의 수용성을 감소하는 결과를 야기할 수가 있다. 따라서 이들 문제를 해결하고자 본 연구에서는 최종 폐기물 부피의 감용화를 위해 롤 압축 기술을 이용하여 분말의 펠렛화 연구를 수행하였다.