• Title/Summary/Keyword: Radiation technology

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Antioxidative Effects of Inula britannica var. chinensis Flower Extracts According to the flowering period and species of Inula britannica var. chinensis (금불초 종(種) 및 개화시기에 따른 금불초 꽃 추출물의 항산화 효능)

  • Kwon, Soon Sik;Jeon, So Ha;Jeon, Ji Min;Cheon, Jong Woo;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.3
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    • pp.195-203
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    • 2013
  • In this study, antioxidative effects of the extracts of different species and flowering periods of Inula britannica were investigated. According to the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity of the extracts, The I. britannica var. chinensis flower extract (500 ${\mu}g/mL$) was measured in a 79.89% free radical scavenging activity, but the flower extracts of similar species (I. britannica var. linariaefolia Regel, I. britannica var. ramosa, I. salicina var. asiatica) did not show any effect on the free radical scavenging activity. The effects of the free radical scavenging activity of I. britannica var. chinensis flower extracts were exhibited in the order of full bloom (93.68%), bud (43.28%), and fallen blossom (14.11%). Next, we established optimum condition of extract solvent, temperature, extraction time. The extract from ethanol at $60^{\circ}C$ showed the most free radical scavenging activity among other conditions and extraction time not relevant in free radical scavenging activity. The protective effects of the extract of I. britannica var. chinensis flower on the photohemolysis of human erythrocytes by using rose bengal were increased in a concentration-dependent manner (5 ~ 50 ${\mu}g/mL$). In particular, the extract in 50 ${\mu}g/mL$ concentration exhibited better protective activity (${\tau}_{50}$ = 116.1 min) than (+)-${\alpha}$-tocopherol (${\tau}_{50}$ = 73.44 min), which is a known lipophilic antioxidant. Principle component of I. britannica var. chinensis flower was identified as quercetin of flavonoids by high-performance liquid chromatography (HPLC). These results indicate that the extract of I. britannica var. chinensis flower can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging free radical and $^1O_2$, and protect cellular membranes against ROS. It is concluded that the antioxidative effects of the extract of I. britannica var. chinensis flower could be applicable to functional cosmetics.

Antioxidative Activities and Antiaging Effects of Geum aleppicum Jacq. Extracts (큰뱀무 추출물의 항산화 활성 및 항노화에 관한 연구)

  • Kim, Min-Ji;Yang, Hyun-Gab;Park, Soo-Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.37 no.2
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    • pp.191-198
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    • 2011
  • In this study, antioxidative effects and inhibitory effects of Geum aleppicum Jacq. extracts on tyrosinase and elastase were investigated. The ethyl acetate fraction of G. aleppicum Jacq. extract ($4.70\;{\mu}g$/mL) showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity (FSC50). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some G. aleppicum Jacq. extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction showed the most prominent ROS scavenging activity ($0.22 \;{\mu}g$/mL). The protective effects of extract/fraction of G. aleppicum Jacq. against the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The G. aleppicum Jacq. extracts suppressed photohemolysis in a concentration dependent manner ($1{\sim}25{\mu}g$/mL), particularly the ethyl acetate fraction exhibited the most prominent celluar protective effect (${\tau}_{50}$, 416.20 min at $10 \;{\mu}g$/mL). The inhibitory effect of G. aleppicum Jacq. extracts on tyrosinase and elastase were investigated to assess their whitening and anti-winkle efficacy. The half maximal inhibitory concentration ($IC_{50}$) of the ethyl acetate fraction on tyrosinase was $95.23\;{\mu}g$/mL. The $IC_{50}$ of 50 % ethanol extract and the ethyl acetate fraction on elastase were $6.27 \;{\mu}g$/mL and $4.31 \;{\mu}g$/mL, respectively. These results indicate that extract/fraction of G. aleppicum Jacq. can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Especially the ethyl acetate fraction of G. aleppicum Jacq. extracts could be applicable to new functional cosmetics for antioxidant, antiaging.

Antioxidant Activity of Rhododendron brachycarpum D. Don Extracts and Its Skin Hydration Effect Measure (만병초 추출물의 항산화활성과 보습효과 측정)

  • Park, Jung-Ok;Lim, Gyu-Nam;Park, Su-Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.36 no.2
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    • pp.157-165
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    • 2010
  • In this study, the antioxidative effects, inhibitory effects on tyrosinase and elastase of Rhododendron brachycarpum D. Don extracts were investigated. And the moisturizing effect of cream containing R. brachycarpum D. Don extract were investigated by clinical trial. The ethyl acetate fraction of R. brachycarpum D. Don extract (1.83 ${\mu}g/mL$) showed the most prominent the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of R. brachycarpum D. Don extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The 50 % extract fraction (0.064 ${\mu}g/mL$) showed the most prominent ROS scavenging activity. The protective effects of extract/fractions of R. brachycarpum D. Don on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The R. brachycarpum D. Don extracts suppressed photohemolysis in a concentration dependent manner (1 ~ 10 ${\mu}g/mL$). The inhibitory effects ($IC_{50}$) of R. brachycarpum D. Don extracts on tyrosinase were determined with ethyl acetate fraction of R. brachycarpum D. Don extract (70.5 ${\mu}g/mL$) and aglycone fraction of extract (122.40 ${\mu}g/mL$). The inhibitory effects ($IC_{50}$) on elastase were determined with ethyl acetate of R. brachycarpum D. Don extract (43.50 ${\mu}g/mL$) and aglycone fraction of extract (20.73 ${\mu}g/mL$). The cream containing the ethyl acetate fraction of R. brachycarpum D. Don extracts was formulated for skin hydration effect and transepidermal water loss (TEWL). The cream containing R. brachycarpum D. Don extract was applied to the right lower arm. After 180 min, the water contents in skin were increased by 1 ~ 4 % than the placebo cream. And TEWL of parts was decreased as 7.7 $g/m^2h$ (experimental cream) and 8.9 $g/m^2h$ (placebo cream) respectively. These results indicate that extract/fractions of R. brachycarpum D. Don can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. And inhibitory activity on tyrosinase of the aglycone fraction could be applicable to new functional cosmetics for whitening and anti-wrinkle products. Also the increase of skin hydration of the cream containing extract could be applicable to new functional cosmetics for antiaging.

Studies on Growth Characteristics and Propagation Method of Introduced Hop (Humulus lupulus L.) Cultivars (홉(Humulus lupulus L.) 도입 품종의 생육특성 및 영양번식 연구)

  • Tae Hyun Ha;Jae Il Lyu;Jun-Hyung Lee;Jaihyunk Ryu;Sang Hoon Park;Si-Yong Kang
    • Korean Journal of Plant Resources
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    • v.36 no.2
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    • pp.181-190
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    • 2023
  • Domestic hop (Humulus lupulus L.) production has been suspended since the early 1990s due to foreign imports, but interest in local production is rising due to the recent craft beer boom in Korea. This study was conducted focusing on the development of growth characteristics and propagation technology for 6 introduced hop cultivars as a basic study for domestic hop production and breeding program. In the hop growth survey conducted in 2021 and 2022, the 5-year-old plants after planting generally showed a tendency to increase the height of strobile setting, strobile size, number and weight of strobile per hill compared to the 4-year-old plants. As a result of the experiment with hop vine cuttings, the average rooting rate of all cultivars was as high as 88% even in only water treatment that were not added with Atonik (Atonik, Arysta, Japan), a rooting agent. There were differences between cultivars in rooting length and rooting rate according to the Atonik treatment method. When checking the survival rate of the rooted cuttings seedlings after transplanting into the soil, it was confirmed that the survival rate of the cuttings in the tissue culture room was significantly lower than that of the cuttings in the greenhouse. However, in transplanting step, cutting plants from culture room condition was strongly inhibited plant growth because of changing environment conditions. As a results of tissue culture, the thidiazuron (TDZ) 1 ㎎/L treatment in the media generated 6 to 9 shoots/explant, while the 6-benzylaminopurine (BAP) 1 ㎎/L treatment generated only 1 to 2 shoots/explant. Therefore, it is more effective to culture by adding TDZ rather than BAP. These results indicated that the development of technology to manage stably after transplanting of cutting or micropropagating plants into potting soil is important for mass propagation of hops.

Generative Adversarial Network-Based Image Conversion Among Different Computed Tomography Protocols and Vendors: Effects on Accuracy and Variability in Quantifying Regional Disease Patterns of Interstitial Lung Disease

  • Hye Jeon Hwang;Hyunjong Kim;Joon Beom Seo;Jong Chul Ye;Gyutaek Oh;Sang Min Lee;Ryoungwoo Jang;Jihye Yun;Namkug Kim;Hee Jun Park;Ho Yun Lee;Soon Ho Yoon;Kyung Eun Shin;Jae Wook Lee;Woocheol Kwon;Joo Sung Sun;Seulgi You;Myung Hee Chung;Bo Mi Gil;Jae-Kwang Lim;Youkyung Lee;Su Jin Hong;Yo Won Choi
    • Korean Journal of Radiology
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    • v.24 no.8
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    • pp.807-820
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    • 2023
  • Objective: To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. Materials and Methods: This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1-7 according to acquisition conditions. CT images in groups 2-7 were converted into the target CT style (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. Results: Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2-7 improved after CT conversion (original vs. converted: 0.63 vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists' scores were significantly higher (P < 0.001) and less variable on converted CT. Conclusion: CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

Manufacturing Techniques of Bronze Seated Bodhisattva Statue of Goseongsa Temple in Gangjin (강진 고성사 청동보살좌상의 제작기술 연구)

  • LEE Seungchan;BAE Gowoon;CHUNG Kwangyong
    • Korean Journal of Heritage: History & Science
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    • v.57 no.1
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    • pp.146-159
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    • 2024
  • In this study, a study on the production technology of the Buddha statue and the production of raw material origin was conducted through scientific analysis on the Bronze seated Bodhisattva Statue of Goseongsa Temple, a treasure. As a result of microstructure analysis through a metal microscope, it was confirmed that the microstructure of the Bronze seated Bodhisattva Statue of Goseongsa Temple was a process-type dendritic structure, and the casting structure of bronze was well represented, so it was manufactured through casting. Subsequently, as a result of analyzing the alloy composition ratio through SEM-EDS, it was identified as a ternary alloy with 81.26 wt% of copper (Cu) and 16.42 wt% of tin (Sn) and 1.72 wt% of lead (Pb). The results of the analysis of lead isotope ratios using a thermal ionization mass spectrometer (TIMS) were substituted into the distribution of lead isotope ratios on the Korean Peninsula, it was shown in corresponding to Jeolla-do and Chungcheong-do regions and North and South Gyeongsang Province. This suggests that the raw materials used in their production were likely sourced from the mines around Goseong Temple in Gangjin. Despite the fact that the statue is a medium and large Buddha with a total height of 51 centimeters, 1.72 wt% of lead (Pb) was found as a result of alloy composition ratio analysis, which showed a similar composition to the lead content ratio of small bronze and gilt-bronze Buddha statues. Therefore, we compared and analyzed the results of the analysis of the composition ratio of the alloys of bronze and gilt bronze statues, which has been scientifically analyzed with a compositional age similar to that of the Bronze seated Bodhisattva Statue of Goseongsa Temple. Comparison results, Various factors, such as the size of the Buddha statue as well as its stylistic characteristics and the age of composition, may exist in determining the alloy composition ratio of the bronze and gilt bronze Buddha statues, and it was confirmed that the alloy composition ratio or casting technology was properly adjusted when the Buddha statue was created. In other words, it is judged that a more comprehensive system of Buddha statue production technology should be investigated by conducting archaeological and art history studies on stylistic characteristics and age of composition, as well as scientific analysis results such as observation of internal structure, microstructure observation, and analysis of alloy composition ratio using radiation transmission irradiation.

Consideration on Shielding Effect Based on Apron Wearing During Low-dose I-131 Administration (저용량 I-131 투여시 Apron 착용여부에 따른 차폐효과에 대한 고찰)

  • Kim, Ilsu;Kim, Hosin;Ryu, Hyeonggi;Kang, Yeongjik;Park, Suyoung;Kim, Seungchan;Lee, Guiwon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.20 no.1
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    • pp.32-36
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    • 2016
  • Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.

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Antibacterial and Antioxidative Activities of Quercus acutissima Carruth Leaf Extracts and Isolation of Active Ingredients (상수리나무 잎 추출물의 항균 및 항산화 활성과 활성 물질 분리)

  • Park, Soo-Nam;Kim, So-I;Ahn, You-Jin;Kim, Eun-Hee
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.35 no.2
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    • pp.159-169
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    • 2009
  • In this study, the antibacterial activity, antioxidative effects, inhibitory effects on tyrosinase, inhibitory effects on elastase, and components of Quercus acutissima Carruth leaf extracts were investigated. MIC values of ethyl acetate fraction from Q. acutissima Carruth leaf on P. acnes, S. aureus, P. ovale, and E. coli were 0.13 %, 0.25 %, 0.13 % and 0.25 %, respectively. The results showed that the antibacterial activity of the ethyl acetate fraction was the highest in the S. aureus, P. acnes, and P. ovale. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fractions of Q. acutissima Carruth. leaf was in the order: 50 % ethanol extract (12.13 ${\mu}g/mL$) < ethyl acetate fraction (7.07 ${\mu}g/mL$) < deglycosylated flavonoid aglycone fraction (6.20 ${\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some Q. acutissima Carruth leaf extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol-dependent chemiluminescence assay. The order of ROS scavenging activity was 50 % ethanol extract ($OSC_{50}$, 1.81 ${\mu}g/mL$) < ethyl acetate fraction (1.70 ${\mu}g/mL$) < deglycosylated flavonoid aglycone fraction (0.70 ${\mu}g/mL$). Deglycosylated flavonoid aglycone fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Q. acutissima Carruth leaf on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The Q. acutissima Carruth leaf extracts suppressed photohemolysis in a concentration dependent manner, particularly deglycosylated flavonoid aglycone fraction exhibited the most prominent celluar protective effect (${\tau}50$, 220.00 min at 25 ${\mu}g/mL$). Aglycone fractions obtained from the deglycosylation reaction of ethyl acetate fraction among the Q. acutissima Carruth leaf extracts, showed 3 bands (QA 1, QA2 and QA3) on TLC. TLC chromatogram of ethyl acetate fraction of Q. Carruth. leaf extract revealed 4 bands (QA 1 ${\sim}$ QA 4), Among them, kaempferol (QA 1), quercetin (QA 2), and gallic acid (QA 3) were identified. The inhibitory effect ($IC_{50}$) of aglycone fraction on tyrosinase was 65.7 ${\mu}g/mL$. The inhibitory effect ($IC_{50}$) of aglycone fraction on elastase was 24.50 ${\mu}g/mL$. These results indicate that extract/fractions of Q. acutissima Carruth. can functionized as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Extract/fractions of Q. acutissima Corruth can be applicable to new functional cosmetics for antioxidant, antiaging, antibacterial activity.

Reducing error rates in general nuclear medicine imaging to increase patient satisfaction (핵의학 일반영상 검사업무 오류개선 활동에 따른 환자 만족도)

  • Kim, Ho-Sung;Im, In-Chul;Park, Cheol-Woo;Lim, Jong-Duek;Kim, Sun-Geun;Lee, Jae-Seung
    • Journal of the Korean Society of Radiology
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    • v.5 no.5
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    • pp.295-302
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    • 2011
  • To n the field of nuclear medicine, with regard to checking regular patients, from the moment they register up to the doctor's diagnosis, the person in charge of the checks can find errors in the diagnosis, reexamine, reanalyze the results or save images to PACS. Through this process, the results obtained from the readings are delayed due to checks and additional tests which occur in hospitals, causing patient satisfaction and affected reliability. Accordingly, the purpose is to include visual inspection of the results to minimize error, improve efficiency and increase patient satisfaction. Nuclear medicine and imaging tests from examines at Asan Medical Center, Seoul, from March 2008 to December 2008, were analyzed for errors. The first stage, from January 2009 to December 2009, established procedures and know-how. The second stage from January 2010 until June 2010 conducted Pre-and Post-filtering assessment, and the third stage from July 2010 until October 2010 consisted of cross-checks and attaching stickers and comparing error cases. Of 92 errors, the 1st, 2nd and 3rd stage had 32 cases, and there were 46 cases after the 4th stage, with the overall errors reduced by 74.3% from 94.6%. In the field of general nuclear medicine, where various kinds of checks are performed according to the patient's needs, analysis, image composition, differing images in PACS, etc, all have the potential for mistakes to be made. In order to decrease error rates, the image can continuously Cross-Check and Confirm diagnosis.

Evaluation of Dosimetry and Image of Very Low Dose CT Attenuation Correction for Pediatric PET/CT: Phantom Study (팬텀을 이용한 소아 PET/CT 검사 시 감쇄보정 CT 선량과 영상 평가)

  • Bahn, Young-Kag;Kim, Jung-Yul;Park, Hoon-Hee;Kang, Chun-Goo;Lim, Han-Sang;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.2
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    • pp.53-59
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    • 2011
  • Purpose: To evaluate the dosimetry and image of very low does CT attenuation correction for phantom using pediatric PET/CT. Materials and methods: three PET / CT scanners (Discovery STe, BiographTruepoint 40, Discovery 600) as a child-size acrylic phantom and ion chamber dosimeter (Unfous Xi CT, Sweden) using a CT image acquisition parameters (10, 20, 40, 80, 100, 160 mA; 80, 100, 120, 140 kVp) by varying the depth dose and evaluate $CTDI_{vol}$ value. And each attenuation corrected PET/CT images used NEMA PET Phantom$^{TM}$ (NU2-1994) was evaluated by SUV. Results: Abdominal diagnosis CT dose in general pediatric (about 10 ages) parameter (100 kVp, 100 mA) than very low dose CT parameter (80 kVp, 10 mA) at the depth dose was reduced approximately 92%, $CTDI_{vol}$ was reduced to about 88%. Each CT attenuation corrected parameters PET images showed no change in the value of SUV. Conclusion: for pediatric patients, PET/CT scan can be obtained with very low dose attenuation correction CT (80 kVp, 10 mA), and such attenuation correction CT dose was reduced 100 fold than diagnosis CT dose. PET / CT scan used very low dose CT attenuation correction in pediatric patients can be helpful in reducing radiation dose.

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