• 제목/요약/키워드: ff

검색결과 729건 처리시간 0.021초

Use of Quantitative Vertebral Bone Marrow Fat Fraction to Assess Disease Activity and Chronicity in Patients with Ankylosing Spondylitis

  • Ga Young Ahn;Bon San Koo;Kyung Bin Joo;Tae-Hwan Kim;Seunghun Lee
    • Korean Journal of Radiology
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    • 제22권10호
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    • pp.1671-1679
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    • 2021
  • Objective: We quantitatively measured the fat fraction (FF) in the vertebrae of patients with ankylosing spondylitis (AS) using magnetic resonance imaging (MRI) and investigated the role of FF as an indicator of both active inflammation and chronicity. Materials and Methods: A total of 52 patients with AS who underwent spinal MRI were retrospectively evaluated. The FF values of the anterosuperior and anteroinferior corners of the bone marrow in the L1-S1 spine were assessed using the modified Dixon technique. AS activity was measured using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), AS Disease Activity Score (ASDAS), and serum inflammatory marker levels. AS disease chronicity was assessed by AS disease duration and the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS). Univariable and multivariable regression analyses were conducted to investigate the correlation between FF and other clinical characteristics. Results: The mean FF ± standard deviation of the total lumbar spine was 43.0% ± 11.3%. At univariable analysis, spinal FF showed significant negative correlation with BASDAI (β = -0.474, p = 0.002) and ASDAS with C-reactive protein (ASDAS-CRP; β = -0.478, p = 0.002) and a significant positive correlation with AS disease duration (β = 0.440, p = 0.001). After adjusting for patient age, sex, and total mSASSS score, spinal FF remained significantly negatively correlated with BASDAI (β = -0.543, p < 0.001), ASDAS-CRP (β = -0.568, p < 0.001), and ASDAS with erythrocyte sedimentation rate (β = -0.533, p = 0.001). Spinal FF was significantly lower in patients with very high disease activity (ASDAS-CRP > 3.5) than in those with only high disease activity (2.1 ≤ ASDAS-CRP ≤ 3.5) (p = 0.010). Conclusion: Spinal FF may help assess both AS disease activity and chronicity.

호흡보호구에서 마스크커버가 밀착계수에 미치는 영향 (The Effects of Mask Covers on the Fit Factorsof Respirators)

  • 한돈희
    • 한국산업보건학회지
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    • 제23권3호
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    • pp.177-183
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    • 2013
  • Objectives: 본 연구는 호흡보호구의 밀착도의 척도인 밀착계수 (FF)를 이용하여마스크에 마스크 커버를 씌웠을 때 호흡보호구의 밀착에 어떠한 영향을 미치는지 평가하고자 하였다. Methods: 3개 회사의 호흡보호구 (1개 1/4형, 2개 반면형)를 선정하여25의 피검자 (남자 16, 여자 9)에게 마스크 커버를 씌우지 않은 마스크와 씌운 마스크를 착용하게 하고 정량적인 밀착도 검사 (QNFT)를 실시하여 밀착계수 (FF)를 측정하였다. 동일한 조건에서 각 피검자에게 3번의 QNFT를 실시였으므로 한 마스크 당 씌운 것 75회, 씌우지 않은 것 75회, 150회를 시행하여 비교하였고 3개 마스크에 총 450회를 시행하였다. Results: 마스크 A (반면형)는 예상과는 다르게 마스크 커버가 있는 경우가 없는 경우보다 FF값이 더 높게 나왔으며 (p<0.05), 마스크 B (1/4형)와 마스크 C (반면형)은 마스크 커버가 없는 경우가 있는 경우보다 FF가 높게 나왔다. 마스크 B는 마스크 커버와 관계없이 FF가 너무 낮아 밀착에 문제가 있다고 판단되었으며 반대로 마스크 C는 마스크 커버에 영향을 받았으나 FF가 매우 높게 나와 밀착에는 큰 문제가 없다고 판단되었다. Conclusions: 본 연구 결과는 마스크에 자신의 마스크 커버를 씌울 경우 밀착에 큰 영향은 없는 것으로 나타났으나 FF만 가지고 실험했기 때문에 제한적이며 실제 작업현장에서 밀착도에 영향을 주지 않는지를 결정하기 위해서는 작업장보호계수 (WPF)를 이용한 보다 많은 연구가 필요하다.

Effects of force fields for refining protein NMR structures with atomistic force fields and generalized-Born implicit solvent model

  • Jee, Jun-Goo
    • 한국자기공명학회논문지
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    • 제18권1호
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    • pp.24-29
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    • 2014
  • Atomistic molecular dynamics (MD) simulation has become mature enabling close approximation of the real behaviors of biomolecules. In biomolecular NMR field, atomistic MD simulation coupled with generalized implicit solvent model (GBIS) has contributed to improving the qualities of NMR structures in the refinement stage with experimental restraints. Here all-atom force fields play important roles in defining the optimal positions between atoms and angles, resulting in more precise and accurate structures. Despite successful applications in refining NMR structure, however, the research that has studied the influence of force fields in GBIS is limited. In this study, we compared the qualities of NMR structures of two model proteins, ubiquitin and GB1, under a series of AMBER force fields-ff99SB, ff99SB-ILDN, ff99SB-NMR, ff12SB, and ff13-with experimental restraints. The root mean square deviations of backbone atoms and packing scores that reflect the apparent structural qualities were almost indistinguishable except ff13. Qualitative comparison of parameters, however, indicates that ff99SB-ILDN is more recommendable, at least in the cases of ubiquitin and GB1.

난알부민으로 유발된 생쥐의 알레르기 비염에 연교, 유근피, 좌귀음이 미치는 영향 (Effects of Forsythiae Fructus, Ulmi Cortex and JwaGwiEum in Allergic Rhinitis Induced by Ovalbumin in Mice)

  • 김빛나래
    • 대한한방소아과학회지
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    • 제31권2호
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    • pp.34-47
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    • 2017
  • Objectives In the past, studies have been shown that Forsythiae Fructus (FF), Ulmi Cortex (UC) and JwaGwiEum (JGE) are effective in treating allergic reactions. However, no report shows the difference in effects of FF, UC and JGE in allergic rhinitis (AR). Therefore, the purpose of this study was to differentiate the effects of FF, UC and JGE in AR induced by ovalbumin (OVA) in mice. Methods From this experiment, the effects of FF, UC and JGE were several - changes in body weight, hematologic changes such as WBC, RBC, Hb and PLT counts, immunological changes such as levels of histamine, IgE, IL-4 and expressions of iNOS & COX-2 mRNA. Moreover, histological change of nasal mucosa was also investigated. Results FF administration group and JGE administration group significantly inhibited level of IgE compared to the control group. Also, FF administration group, UC administration group and JGE administration group inhibited IL-4 and expressions of iNOS & COX-2 mRNA. In histological assessment, FF administration group, UC administration group and JGE administration group showed reduced amount of subepithelial edema, desquamated mucosa and hyperplasia of basement membrane from OVA.

역전파 알고리즘을 이용한 FF-PID 제어 시스템 구현 (Realization for FF-PID Controlling System with Backward Propagation Algorithm)

  • 류재훈;허창우;류광렬
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2007년도 춘계종합학술대회
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    • pp.171-174
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    • 2007
  • 본 논문은 역전파 알고리즘을 이용한 FF-PID 제어 시스템 구현에 관한 연구이다. 영상의 인식은 신경망 역전파를 사용하여 학습시킨다. FF-PID 제어기는 신경망의 목표치에 대한 출력층 오차값을 제어값으로 사용하여 이동물체의 응답특성을 향상시킨다. 실험결과, 시스템의 응답시간은 약 2.7(sec)였으며, 일반적인 차영상기법에 비하여 약 15% 목표치 응답이 향상되어, 효과적인 이동물체의 제어가 가능하였다.

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PCRAM Flip-Flop Circuits with Sequential Sleep-in Control Scheme and Selective Write Latch

  • Choi, Jun-Myung;Jung, Chul-Moon;Min, Kyeong-Sik
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제13권1호
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    • pp.58-64
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    • 2013
  • In this paper, two new flip-flop circuits with PCRAM latches that are FF-1 and FF-2, respectively, are proposed not to waste leakage during sleep time. Unlike the FF-1 circuit that has a normal PCRAM latch, the FF-2 circuit has a selective write latch that can reduce the switching activity in writing operation to save switching power at sleep-in moment. Moreover, a sequential sleep-in control is proposed to reduce the rush current peak that is observed at the sleep-in moment. From the simulation of storing '000000' to the PCRAM latch, we could verify that the proposed FF-1 and FF-2 consume smaller power than the conventional 45-nm FF if the sleep time is longer than $465{\mu}s$ and $95{\mu}s$, respectively, at $125^{\circ}C$. For the rush current peak, the sequential sleep-in control could reduce the current peak as much as 77%.

Effect of Zinc-enriched Yeast FF-10 Strain on the Alcoholic Hepatotoxicity in Alcohol Feeding Rats

  • Cha, Jae-Young;Heo, Jin-Sun;Cho, Young-Su
    • Food Science and Biotechnology
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    • 제17권6호
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    • pp.1207-1213
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    • 2008
  • The possible protective effects of highly zinc-containing yeast Saccharomyces cerevisiae, FF-10 strain, isolated from tropical fruit rambutan on acute alcoholic liver injury in rats were evaluated. Zinc concentration in this strain was 30.6mg%. The activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and $\gamma$-glutamyl transpeptidase ($\gamma$-GTP) were highly increased when alcohol was treated, relative to the normal rats. Also, a highly significant increase in the blood alcohol and acetaldehyde levels by alcohol treatment was observed. Administration of FF-10 strain markedly prevented alcohol-induced elevation of the activities of serum ALT, AST, and $\gamma$-GTP, and the levels of blood alcohol and acetaldehyde, and these reduced levels reached to that of normal rats. As compared with alcohol treated control rats, the FF-10 strain supplementation showed highly decreased the triglyceride concentration in serum. Alcohol treatment induced the marked accumulation of small lipid droplets, hepatocytes necrosis, and inflammation, but FF-10 strain administration attenuated to alcohol-induced accumulation of small lipid droplets and hepatocyte necrosis in the liver. Therefore, the current finding suggests that zinc-enriched yeast FF-10 strain isolated from tropical fruit rambutan may have protective effect against alcohol-induced hepatotoxicity.

푸르푸랄의 화학적 촉매전환을 통한 테트라히드로푸르푸릴 알코올 생산 공정 개발 및 경제성 평가 (Process Development and Economic Evaluation for Catalytic Conversion of Furfural to Tetrahydrofurfuryl Alcohol)

  • 변재원;한지훈
    • Korean Chemical Engineering Research
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    • 제55권5호
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    • pp.609-617
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    • 2017
  • 목질계 바이오매스는 바이오 연료 및 바이오 화학제품 생산을 위한 재생 가능 자원이다. 푸르푸랄(furfural, FF)은 목질계 바이오매스의 헤미셀룰로스로부터 화학적 촉매전환으로 유도되는 주요한 플랫폼 케미칼이다. 테트라히드로푸르푸릴 알코올(Tetrahydrofurfuryl alcohol, THFA)은 FF의 유도체로 열적 화학적 안정성을 지닌 친환경 용매로 이용 가능하다. FF를 THFA로 전환하는 실험적 연구가 다수 존재함에도 불구하고, FF로부터 THFA의 대량생산에 관한 경제적 실현가능성에 관한 연구는 거의 수행되지 않았다. 개발된 전환기술의 상용화 단계에서 기술적 병목점 확인과 스케일업 문제의 해결을 위한 정보를 얻기 위해 실증플랜트 규모의 연구가 필요하다. 본 연구에서는 FF의 THFA로의 화학적 촉매전환에 대해 공정 시뮬레이션 및 기술경제성 평가가 수행되며, 3가지 단계(통합 공정 디자인, 열 통합, 경제성 평가)를 거친다. 실험연구 결과를 기반으로 전환공정과 분리공정을 포함하는 실증플랜트 규모의 통합공정이 설계된다. FF 처리량은 일일 255톤이며, FF로부터 THFA로의 수율은 63.2~67.9 mol%이다. 통합공정에 대해 열 통합을 수행하여 가열요구량을 최초 대비 14.4~16.4% 감소시킬 수 있었다. 최종적으로 경제성 평가를 통해 전체 공정의 주요 비용원을 분석하고 THFA의 최소판매가격을 결정하였다. 개발된 공정에서 생산되는 THFA의 최소판매가격은 1톤당 2,120~2,340 달러로, 현재 THFA의 시장 가격에 근접한다.

아연-고함유 효모 Saccharomyces cerevisiae FF-10 세포액의 항산화효과 (Antioxidative Activity of Zinc-Enriched Saccharomyces cerevisiae FF-10 in In vitro Model Systems)

  • 차재영;박보경;안희영;엄경은;전방실;조영수
    • 생명과학회지
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    • 제19권2호
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    • pp.179-184
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    • 2009
  • 아연 고함유 효모 S. cerevisiae FF-10의 항산화능을 검토하기 위하여 DPPH 전자 공여능, linoleic acid을 이용한 ferric thiocyanate법과 TBA법에 의한 과산화지질 생성 정도 및 흰쥐 간 조직 생체막을 이용한 TBARS법에 의한 과산화지질 생성 정도를 측정하였다. 본 실험은 효모 생육배지인 YM 기본배지와 아연 생산량을 증대시키는 YM 최적배지에서 각각 배양된 S. cerevisiae FF-10의 세포 파쇄액의 항산화 활성을 비교하였다. DPPH 전자 공여능은 양성 대조구로 사용한 BHT에서 가장 높았고, YM 기본배지 보다는 YM 최적배지에서 배양된 FF-10 세포 파쇄액에서 항산화 활성이 높게 나타났다. 간 조직 생체막 과산화지질 생성 정도는 BHT > 최적 생산배지 > 기본배지 순으로 저해되었다. Linoleic acid를 이용한 과산화지질 생성정도는 음성 대조구에서 반응 1일째부터 급격히 증가한 후 반응종료일까지 계속 그 수준이 유지되었고, 양성 대조구인 BHT 처리구에서는 과산화지질 생성이 억제되어 높은 항산화활성이 확인되었으며, YM 기본배지 보다는 YM 최적배지에서 높은 과산화지질 생성 저해활성을 보였다. 이상의 결과에서 in vitro 항산화 실험계인 DPPH radical scavenging activity, 간 조직 생체막과 linolic acid 지방산을 이용한 ferric thiocyanate and TBARS 측정에서 항산화 활성은 양성 대조구인 BHT 보다는 낮았으나 최적배지에서 배양된 아연 고함유 효모 S. cerevisiae FF-10 균주의 세포 파쇄액에서 모두 높게 나타나 in vivo 항산화 실험계에서도 확인이 필요한 것으로 사료되어 진다.

Effects of Cumulus Cells and Follicular Fluid on Plasminogen Activator Activity during In Vitro Maturation of Porcine Oocytes

  • Ann Ji-Young;Sa Soo-Jin;Cao Yang;Lee Sang-Young;Cheon Hee-Tae;Yang Boo-Keun;Park Choon-Keun
    • Reproductive and Developmental Biology
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    • 제30권2호
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    • pp.135-141
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    • 2006
  • The present study was conducted to investigate the effects of cumulus cells and porcine follicular fluid (pFF) on plasminogen activator (PA) activity and oocytes maturation in vitro in the pig. The cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) were incubated in NCSU-23 medium with or without 10% pFF for 0, 24, or 48 hr. In the presence of cumulus cells, the proportions of oocytes matured to metaphase-II stage were significantly (P<0.05) higher in medium with pFF than without pFF (69.8 vs. 37.7%, respectively). When COCs and DOs were cultured in the presence of pFF, tissue-type PA (tPA), urokinase-type PA (uPA), and tPA-PA inhibitor (tPA-PAI) were observed in COCs, and PA activities were higher at 48 hr than 24 hr. When COCs and DOs were cultured in the absence of pFF, tPA and tPA-PAI were observed in COCs, and PA activities were increased as duration of culture increased. No PA activities were detected in DOs regardless of pFF supplementation. When porcine oocytes were cultured in the presence of pFF for 24 and 48 hrs, the activities of tPA-PAI, tPA, and uPA were observed in both COCs and DOs. In medium of absence of pFF, PA activities were observed in oocytes with cumulus cells only. On the other hand, three plasminogen-dependent lytic bands (tPA-PAI, tPA, and uPA) were observed in pFF cultures. Particularly uPA activity was higher than the other kinds of PA activity. When oocytes and cumulus cells were separated from porcine COCs at 0 hr of culture, tPA-PAI, tPA, and uPA were detected in cumulus cells at 48 hr of culture, but no PA activities were in DOs. The presence of pFF and cumulus cells in maturation medium stimulated not only nuclear and cytoplasmic maturation in porcine COCs, but also PA production by cumulus cells and COCs. It is possible that PAs produced by cumulus cells migrated through the gap junction between oocyte and cumulus cells. These results suggest that porcine oocytes have no ability to produce PA themselves.