• 제목/요약/키워드: Activity/Attenuation

검색결과 161건 처리시간 0.028초

Feasibility of Natural Attenuation for TCE Anaerobic Reductive Dechlorination Using Microsized Corn-Oil Droplet as an Activator (Microsized Corn-Oil Droplet (MOD)의 Trichloroethylene (TCE) 생물학적 탈염소화 분해 자연저감 완효성 촉진제 적용성 평가)

  • Kyungjin Han;Huiyun Kim;Sooyoul Kwon;Young Kim
    • Journal of Korean Society on Water Environment
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    • 제40권1호
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    • pp.11-18
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    • 2024
  • Recently, enhanced in situ bioremediation using slow substrate release techniques has been actively researched for managing TCE-contaminated groundwater. This study conducted a lab-scale batch reactor experiment to evaluate the feasibility of natural attenuation for TCE dechlorination using microsized corn-oil droplet (MOD) as an activator considering the following three factors: 1) TCE dechlorination in the presence or absence of MOD; 2) TCE dechlorination in the presence or absence of inactivator of native microbial activity; and 3) MOD concentration effects on TCE dechlorination. Batch reactors were constructed using site groundwater and soil in which Dehalococcoides bacteria were present. Without MOD, TCE was decomposed into dichloroethylene (DCE). However, other by-products of TCE dechlorination were not detected. With MOD, DCE, vinyl chloride (VC), and ethylene (ETH) were sequentially observed. This result confirmed that MOD effectively supplied electrons to complete dechlorination of TCE to ETH. However, when an excess of MOD was provided, it formed unfavorable conditions for anaerobic digestion because dechlorination reaction did not proceed while propionic acid was accumulated after DCE was generated. Therefore, if an appropriate amount of MOD is supplied, MOD can be effectively used as a natural reduction activator to promote biodegradation in an aquifer contaminated by TCE.

Effect of Extended Field of View on Measurements of Standardized Uptake Value in PET/CT (PET/CT검사에서 CT의 확대 유효시야 적용이 표준화섭취계수에 미치는 영향)

  • Park, Soon-Ki;Nam, Ki-Pyo;Kim, Kyeong-Sik;Shin, Sang-Ki
    • The Korean Journal of Nuclear Medicine Technology
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    • 제13권1호
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    • pp.82-85
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    • 2009
  • Purpose: The purpose of this study was to evaluate the effect of extended CT field of view (FOV) on PET/CT of Standardized uptake value (SUV) when imaging extends beyond the CT FOV. Materials and Methods: CT images were reconstructed at different FOV sizes (500 and 700 mm). Two sets of CT images were reconstructed from the CT projection data by using two FOV sizes. Twenty patients were used in this study. PET images were reconstructed using attenuation maps with 500 mm CT FOV and 700 mm extended CT FOV images. Region of interests (ROIs) drawn on the PET images. In addition, twenty patients' PET images reconstructed by 500 mm CT FOV and 700 mm extended CT FOV were compared with $SUV_{max}$. Results: When using attenuation maps with 700 mm extended CT FOV, the $SUV_{max}$ analysis of liver (p=0.000), lung (p=0.007), mediastinum (p=0.001) were statistically significant. Conclusions: 700 mm extended CT FOV helps to recover the true activity distribution in the PET emission data. In addition, 700 mm extended CT FOV has affected SUV measurement of liver, lung, mediastinum.

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The Characteristics of Biodegradation for VOCs in Unsaturated Soil by Bio-filter (Bio-filter에 의한 토양중의 VOCs 분해특성)

  • Sohn Jong-Ryeul;Jang Myung-Bae;Cho Kwang-Myung
    • Journal of environmental and Sanitary engineering
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    • 제19권4호
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    • pp.19-24
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    • 2004
  • The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOCs transport, microbial activity, and sorptive interactions in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOCs transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations from diffusion experiments using toluene as a representative VOCs in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas putida G7 md Fl, as the sole active microbial species. The gas-liquid mass-transfer was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils. Therefore we found that Pseudomonas putida G7 and Fl were very effective to remove of refractory pollutants such as toluene in soil by Bio-filter

Effects of Antioxidant on Reduction of Hindlimb Muscle Atrophy Induced by Cisplatin in Rats (항산화제가 시스플라틴에 의해 유발된 쥐의 뒷다리근 위축 경감에 미치는 영향)

  • Kim, Jin Il;Choe, Myoung-Ae
    • Journal of Korean Academy of Nursing
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    • 제44권4호
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    • pp.371-380
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    • 2014
  • Purpose: The purpose of this study was to examine the effects of Cu/Zn SOD on reduction of hindlimb muscular atrophy induced by cisplatin in rats. Methods: Forty-two rats were assigned to three groups; control group, Cisplatin (CDDP) group and cisplatin with Cu/Zn SOD (CDDP-SOD) group. At day 35 hindlimb muscles were dissected. Food intake, activity, withdrawal threshold, muscle weight, and Type I, II fiber cross-sectional area (CSA) of dissected muscles were measured. Relative SOD activity and expression of MHC and phosphorylated Akt, ERK were measured after dissection. Results: Muscle weight and Type I, II fiber CSA of hindlimb muscles in the CDDP group were significantly less than the control group. Muscle weight and Type I, II fiber CSA of hindlimb muscles, food intake, activity, and withdrawal thresholds of the CDDP-SOD group were significantly greater than the CDDP group. There were no significant differences in relative SOD activities of hindlimb muscles between the CDDP-SOD and CDDP groups. MHC expression and phosphorylated Akt, ERK of hindlimb muscles in the CDDP-SOD group were significantly greater than the CDDP group. Conclusion: Cu/Zn SOD attenuates hindlimb muscular atrophy induced by cisplatin through increased food intake and activity. Increment of phosphorylated Akt, ERK may relate to attenuation of hindlimb muscular atrophy.

Effect of Subfractions of Carthamus tinctorius L. Semen on the Lipid Peroxidation and Oxygen Free Radical Scavenging Enzyme Activities in CCl_4$-induced Hepatotoxic Rats (홍화자 분획물의 사염화탄소 유발 간손상 흰쥐에서 지질과산화와 oxygen free radical 제거 효소 활성도에 미치는 영향)

  • 정기화;정춘식;정정숙
    • Journal of Food Hygiene and Safety
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    • 제14권2호
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    • pp.179-185
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    • 1999
  • Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of the subfractions of butanol fraction has been evaluated by analyzing oxygen free radical scavenging enzyme activities and histopathological examinations. In BS-5 subfraction treated group, the activity of superoxide dismutase has been significantly increased as compared with that of CCl4, treated rats. Antioxidant activity has been evaluated by the examination of the scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radical. BS-5 subfraction has shown strong antioxidant activities. The histopathological examination showed that the treatment of BS-5 subfraction has relieved the ballooning degeneration of hepatocytes which had been generated by CCl4. It appears that the protective effect of BS-5 subfraction would be mediated of the attenuation of lipid peroxidation by acting as a free radical scavenger, which were based on the increase of superoxide dismutase activity.

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3,4-Dihydroxytoluene suppresses UVB-induced wrinkle formation by inhibiting Raf-1

  • Park, Sang-Hee;Kang, Nam Joo
    • Korean Journal of Food Science and Technology
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    • 제52권4호
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    • pp.385-395
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    • 2020
  • This study examined the effect of 3,4-dihydroxytoluene (DHT) on UVB-induced photoaging and determined its molecular mechanisms, using HaCaT human keratinocytes and SKH-1 hairless mice. DHT suppressed UVB-induced matrix metalloproteinase-1 (MMP-1) expression in HaCaT cells. In vivo data from mouse skin supported that DHT decreased UVB-induced wrinkle formation, epidermal thickness, and matrix metalloproteinase-13 (MMP-13) expression. DHT appeared to exert its anti-aging effects by suppressing UVB-induced Raf-1 kinase activity and subsequent attenuation of UVB-induced phosphorylation of MEK, ERK, and p90RSK in HaCaT cells. In vitro and in vivo pull-down assays revealed that DHT bound with Raf-1 in ATP-noncompetitive manner. Overall, DHT appears to anti-photoaging effects in vitro and in vivo through the suppression of Raf-1 kinase activity and may have potential as a treatment for the prevention of skin aging.

Enhancement of the Antioxidant and Anti-inflammatory Activity of Hizikia fusiforme Water Extract by Lactic Acid Bacteria Fermentation (유산균 발효에 의한 톳 (Hizikia fusiforme) 추출액의 항산화 및 항염증 활성 증가)

  • Song, Ho-Su;Eom, Sung-Hwan;Kang, Young-Mi;Choi, Jong-Duck;Kim, Young-Mog
    • Korean Journal of Fisheries and Aquatic Sciences
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    • 제44권2호
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    • pp.111-117
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    • 2011
  • We previously reported that fermentation by Lactobacillus brevis LB-20 isolated from Kimchi resulted in improvement of the sensory quality of Hizikia fusiforme water extract. This study was conducted to evaluate the possible application of lactic acid bacteria fermentation to improve the functional qualities of H. fusiforme extract. L. brevis LB-20 was inoculated and cultivated in H. fusiforme extract. The antioxidant and anti-inflammatory activities of extract were then assayed both before and following fermentation for two days. Antioxidant activity was determined by assaying levels of radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, superoxide, and alkyl radical. Lactic acid bacterial fermentation of H. fusiforme extract resulted in enhancement of antioxidant activity. The greatest enhancement of antioxidant activity was seen in the hydroxyl radical scavenging assay that incorporated 0.5 mg/mL of raw and fermented H. fusiforme extract. Fermented extract exhibited greater (21.95%) inhibition of nitric oxide synthesis than did raw extract (14.66%) at a concentration of 1 mg/mL. The fermented extract exerted its potent anti-inflammatory activity via attenuation of expression of inflammation-related cytokine proteins (TNF-${\alpha}$ and iNOS).

Effects of Erythropoietin on Memory Deficits and Brain Oxidative Stress in the Mouse Models of Dementia

  • Kumar, Rohit;Jaggi, Amteshwar Singh;Singh, Nirmal
    • The Korean Journal of Physiology and Pharmacology
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    • 제14권5호
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    • pp.345-352
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    • 2010
  • The present study was undertaken to explore the potential of erythropoietin in memory deficits of mice. Memory impairment was produced by scopolamine (0.5 mg/kg, $i.p.$) and intracerebroventricular streptozotocin (i.c.v STZ, 3 mg/kg, $10{\mu}l$, $1^{st}$ and $3^{rd}$ day) in separate groups of animals. Morris water-maze test was employed to assess learning and memory. The levels of brain thio-barbituric acid reactive species (TBARS) and reduced glutathione (GSH) were estimated to assess degree of oxidative stress. Brain acetylcholinesterase enzyme (AChE) activity was also measured. Scopolamine/streptozotocin administration induced significant impairment of learning and memory in mice as indicated by marked decrease in Morris water-maze performance. Scopolamine/streptozotocin administration also produced a significant enhancement of brain AChE activity and brain oxidative stress (an increase in TBARS and a decrease in GSH) levels. Treatment of erythropoietin (500 and 1,000 IU/Kg i.p.) significantly reversed scopolamine- as well as streptozotocin-induced learning and memory deficits along with attenuation of those-induced rise in brain AChE activity and brain oxidative stress levels. It may be concluded that erythropoietin exerts a beneficial effect in memory deficits of mice possibly through its multiple actions including potential anti-oxidative effect.

Activity Object Detection Based on Improved Faster R-CNN

  • Zhang, Ning;Feng, Yiran;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • 제24권3호
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    • pp.416-422
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    • 2021
  • Due to the large differences in human activity within classes, the large similarity between classes, and the problems of visual angle and occlusion, it is difficult to extract features manually, and the detection rate of human behavior is low. In order to better solve these problems, an improved Faster R-CNN-based detection algorithm is proposed in this paper. It achieves multi-object recognition and localization through a second-order detection network, and replaces the original feature extraction module with Dense-Net, which can fuse multi-level feature information, increase network depth and avoid disappearance of network gradients. Meanwhile, the proposal merging strategy is improved with Soft-NMS, where an attenuation function is designed to replace the conventional NMS algorithm, thereby avoiding missed detection of adjacent or overlapping objects, and enhancing the network detection accuracy under multiple objects. During the experiment, the improved Faster R-CNN method in this article has 84.7% target detection result, which is improved compared to other methods, which proves that the target recognition method has significant advantages and potential.

Evaluation of the Effect of Metal Artifacts Varying the Parameters of the Attenuation Map for the artificial Hip Joint in SPECT/CT (SPECT/CT에서 인공고관절에 대한 감쇠보정지도(Attenuation Map)의 매개변수 변화에 따른 금속 인공물(Metal Artifact)의 영향 평가)

  • Kim, Sang Gyu;Kim, Jung Yul;Park, Min Soo;Jo, Seung Hyun;Lim, Han Sang;Kim, Jae Sam
    • The Korean Journal of Nuclear Medicine Technology
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    • 제18권2호
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    • pp.3-7
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    • 2014
  • Purpose SPECT/CT scan to be performed attenuation correction on the basis of CT induce an overestimation of the site due to the beam hardening artifact by metal cover and reduce the images quality. Therefore, this study using a phantom that has been inserted artificial hip joint investigated that effect on the SPECT/CT image causing by metal artifact for varying the parameters of the Attenuation Map. Materials and Methods Siemens Symbia T16 SPECT/CT equipment was used. Artificial hip joint was inserted to SPECT/PET phantom, 17 mm sphere of Bright Streak area in CT image was filled with Tc-99m so that the radiation activity was 8 times compared to background. And then Hot and Background was measured in varying Wide Beam Coefficient on Attenuation Map and RBR (Region to Background Ratio) of Metal and Non-Metal was calculated and analyzed depending on the presence or absence of the hip joint. Results It tended to hot count of Non-Metal and Metal to increase as the value of the manual mode is increased, hot count ratio with the group of both manual mode 0.5 and 0.4 is the best match. Also, in automatic mode, the ratio of RBRNon-Metal and RBRMetal was 1.135, statistically significant difference was not observed in the manual mode 0.5 and 0.4. Conclusion In the automatic mode of Wide Beam Coefficient in attenuation correction map, it was found that it is over-correction by 13.52%, it was possible to minimize the over-correction by the artifact in 0.5 and 0.4 of manual mode. Further studies should be performed in order to apply to a patient with the help of this and it is considered possible to reduce the over-correction by the metal artifact of an artificial hip joint for Hip-Resurfacing Arthroplasty patients, and to improve the diagnostic performance.

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