• 제목/요약/키워드: Growth S Curve

검색결과 385건 처리시간 0.051초

항생제 내성균에 대한 황금 추출물의 항균효과 (Antibacterial Activity of $Scutellaria$ $baicalensis$ Extract against Antibiotic Resistant Bacteria)

  • 장재선;김정희;권문주
    • 한국식품영양학회지
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    • 제24권4호
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    • pp.708-712
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    • 2011
  • This study was focused on the determination of antibacterial activity of $Scutellaria$ $baicalensis$ extract against antibiotic resistant bacteria($Salmonella$ Enteritidis, $Staphylococcus$ $aureus$ and enteroaggregative $E.$ $coli$). Extract of $Scutellaria$ $baicalensis$ were tested for antibacterial activity by paper disc methods. The $Scutellaria$ $baicalensis$ extract in 0.1 g/$m{\ell}$ and 0.2 g/$m{\ell}$ showed a significant antibacterial activity against antibiotic resistant bacteria. Minimum inhibitory concentration (MIC) of $Scutellaria$ $baicalensis$ extract were appeared to 2,048 ${\mu}g/m{\ell}$ at $S.$ Enteritidis, $S.$ $aureus$ and enteroaggregative $E.$ $coli$. Finally, the growth incubation curve was determined using $Scutellaria$ $baicalensis$ extract against $S.$ Enteritidis, $S.$ $aureus$ and enteroaggregative $E.$ $coli$. The growth of $S.$ Enteritidis was significantly inhibited within 10 hours by the addition of at least 10,000 ppm of $Scutellaria$ $baicalensis$ extract. The 10,000 ppm of $Scutellaria$ $baicalensis$ extract retarded the growth of $S.$ $aureus$ and enteroaggregative $E.$ $coli$ more than 10 hours. In conclusion, $Scutellaria$ $baicalensis$ extract might be useful to control antibiotic resistant bacteria $in$ $vitro$.

투농산(透膿散) 및 과루우방탕(瓜蔞牛蒡湯)의 Staphylococcus aureus에 대한 In Vitro 항균력 평가 (In Vitro Antibacterial Effects of Tunong-san and Kwaruwoobang-tang Aqueous Extracts against Staphylococcus aureus)

  • 장세란;박영선;김동철
    • 대한한방부인과학회지
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    • 제25권3호
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    • pp.27-39
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    • 2012
  • Objectives: Recently Ciprofloxacin, used in the treatment of mastitis, showed many serious side effects. The object of this study was to recognize whether TNS and KWT can be used in the treatment of mastitis by observing the in vitro antibacterial effects of TNS and KWT aqueous herbal extracts against S. aureus. Methods: Antibacterial activities of TNS and KWT aqueous extracts against S. aureus ATCC 25923 were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were monitored at MIC and $MIC{\times}2$ levels. The effects on the intracellular killing and bacterial invasion of individual test materials were also observed using Raw 264.6 and MCF-7. The results were compared with Ciprofloxacin, a second generation of quinolone antibiotics in the present study. Results: MIC of aqueous extracts of TNS and KWT against S. aureus were detected as ($0.313{\pm}0.107$) and ($0.137{\pm}0.053$) mg/ml, respectively. MIC of Ciprofloxacin was detected as ($0.469{\pm}0.297$) ${\mu}g/ml$ at same conditions. In addition, TNS, KWT aqueous herbal extracts and Ciprofloxacin were also showed marked dosage-dependent inhibition of bacterial growth, and dramatical inhibitions on the both intracellular killing assays and bacterial invasion using Raw 264.6 and MCF-7 cells were detected. Conclusions: The results obtained in this study suggest that TNS and KWT aqueous herbal extracts showed antibacterial effects against S. aureus, and they also showed dosage-dependent inhibitory effects on the bacterial growth. And they showed the significant intracellular killing and bacterial invasion effects. It means, KWT and TNS may show more potent anti-infectious effects against S. aureus in vivo.

굽힘피로 하중을 받는 배관의 피로균열 발생수명 예측 (Crack Initiation Life Analysis in Notched Pipe Under Cyclic Bending Loads)

  • 곽상록;이준성;김영진;박윤원
    • 대한기계학회논문집A
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    • 제25권10호
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    • pp.1528-1534
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    • 2001
  • In order to improve Leak-Be(ore-Break methodology, more precisely the crack growth evaluation, a round robin analysis was proposed by the CEA Saclay. The aim of this analysis was to evaluate the crack initiation life, penetration life and shape of through wall crack under cyclic bending loads. The proposed round robin analysis is composed of three main topic; fatigue crack initiation, crack propagation and crack penetration. This paper deals with the first topic, crack initiation in a notched pipe under four point bending. Both elastic-plastic finite element analysis and Neuber's rule were used to estimate the crack initiation life and the finite element models were verified by mesh-refinement, stress distribution and global deflection. In elastic-plastic finite element analysis, crack initiation life was determined by strain amplitude at the notch tip and strain-life curve of the material. In the analytical method, Neuber's rule with the consideration of load history and mean stress effect, was used for the life estimation. The effect of notch tip radius, strain range, cyclic hardening rule were examined in this study. When these results were compared with the experimental ones, the global deformation was a good agreement but the crack initiation cycle was higher than the experimental result.

정식 후 초기 생장기 배추의 생장, 광합성 속도 및 기공전도도에 미치는 토양수분의 영향 (Effect of Soil Water Content on Growth, Photosynthetic Rate, and Stomatal Conductance of Kimchi Cabbage at the Early Growth Stage after Transplanting)

  • 김성겸;이희주;이희수;문보흠;이상규
    • 생물환경조절학회지
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    • 제26권3호
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    • pp.151-157
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    • 2017
  • 본 연구는 정식 후 토양의 수분 함량에 따른 배추의 생장과 토양 수분에 따른 배추의 생리 반응 모델 개발을 위한 유효 매개변수를 알아보고자 수행되었다. 처리는 5개 수준으로 각각 0, 200, 300, 400 및 500mL/d/plant로 매일 1회 관수하여 토양 수분 함량 차이로 구분하였다. 토양수분과 기공전도도를 정식 후 10일부터 6일 간격으로 총 5회 측정하였으며(단, 0과 200mL/d/plant 처리구는 총 3회 측정), 광합성기구 활성을 알아보고자 정식 후 25일에 충분히 관수된 처리구(500mL/d/plant)와 결핍 처리구(0mL/d/plant)에서 이산화탄소 포화 곡선을 작성하였고, 정식 후 38일에 생장을 조사하였다(단, 관수량 처리구 0과 200mL/d/plant는 위조되어 정식 후 29일에 생장 조사함). 토양수분과 배추의 기공전도도는 밀접한 관계가 있었으며($r^2=0.999$), 직선의 정의 상관관계로 y = 6097.4x - 4.2984였다. 충분히 관수된 배추의 이산화탄소 포화곡선은 정상적인 포화 곡선을 보였으나, 토양수분이 극도로 결핍된 배추는 체내로 이산화탄소가 확산되어 들어가지 않으며, 광합성 속도도 약 $6.5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ 미만으로 급격히 감소하였다. 충분히 관수된 처리구(500mL/d/plant)에 비하여 토양 수분 결핍구(0mL/d/plant 처리)에서는 약 6.8배 이상 건물생산량이 감소하였다. 그리고 토양의 수분 함량에 따라 엽면적 지수가 로그함수적(y = 16.573 + 3.398 ln x)으로 증가하였고, 결정 계수 $r^2=0.913$로 높은 상관 관계가 있었다. 결과적으로, 정식초기의 토양 수분 함량이 결핍되면 배추의 생장이 지연되며, 광합성 속도와 기공전도도가 낮아지는 것으로 밝혀졌다. 또한, 토양수분 함량과 배추 생장 반응 모델을 기공전도도와 엽면적 지수를 변수로 활용하면 정확도가 우수한 모델을 개발할 수 있을 것으로 기대된다.

한국 서해산 참조기의 연령과 성장 (AGE AND GROWTH OF THE YELLOW CROAKER, PSEUDOSCIAENA MANCHURICA JORDAN ET THOMPSON, IN THE WESTERN COASTAL WATERS OF KOREA)

  • 정상철
    • 한국수산과학회지
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    • 제3권3호
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    • pp.154-160
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    • 1970
  • 우리나라 서해안의 참조기를 대상으로 1967년 6월부터 1968년 5월 사이의 자료에서 체장, 체중 및 인문(鱗紋)조사를 실시하며 다음의 결과를 얻었다. 1. 윤문은 연 1회 형성되고, 형성 시기는 $4\~7$월로, Bae(1960)가 발표한 산란기와 일치되고 있다. 2. 윤군(輪群)별 각 윤경(輪徑)적 평균 성장률은 0.73이었다. 3. 체장(total length)과 인경(鱗徑)과의 관계는 직선 회귀로, 그 관계식은 다음과 같다. L=61.350R+50.184 4. 체중과 체장(total length)과의 관계는 지수 곡선으로 다음과 같다. $$W=4.298L^{3.227}\times10^{-3}$$ 5. Walford의 정차도에 의하여 산출된 이론적인 최대 체강은 346.9mm이었고, 그 관계식은 다음과 같다. $$L_{n+1}=0.6866L_n+10.8730$$ 6. 연령과 체장(total length)과의 관계를 von Bertalanffy의 성장 방정식에 적응시킨 결과 다음과 같았다. $$L_t=346.9(1-e^{-0.376(t+0.609)})$$

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A case of Sotos syndrome presented with end-stage renal disease due to the posterior urethral valve

  • Cho, Won Im;Ko, Jung Min;Kang, Hee Gyung;Ha, Il-Soo;Cheong, Hae Il
    • Journal of Genetic Medicine
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    • 제11권2호
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    • pp.74-78
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    • 2014
  • Sotos syndrome (SS, OMIM 117550) is characterized by prenatal and postnatal overgrowth with multiple congenital anomalies. However, there have been few cases of growth retardation caused by renal failure from infancy. We report a case of dysplasia of the bilateral kidneys with renal failure and poor postnatal growth. A 2-month-old boy visited the emergency room owing to poor oral intake and abdominal distension. He was born at the gestational age of 38 weeks with a birth weight of 4,180 g. After birth, he had feeding difficulty and abdominal distension. Upon physical examination, his height and weight were in less than the 3rd percentile, while his head circumference was in the 50th percentile on the growth curve. He also showed a broad and protruding forehead and high hairline. Blood laboratory tests showed severe azotemia; emergent hemodialysis was needed. Abdominal ultrasonography revealed bilateral renal dysplasia with multiple cysts and diffuse bladder wall thickening. A posterior urethral valve was suggested based on vesicoureterography and abdominal magnetic resonance findings. Results of a colon study to rule out congenital megacolon did not reveal any specific findings. The conventional karyotype of the patient was 46, XY. Array comparative genomic hybridization study revealed a chromosome 5q35 microdeletion including the NSD1 gene, based on which SS was diagnosed. We describe a case of SS presenting with end stage renal disease due to posterior urethral valve. The typical somatic overgrowth of SS in the postnatal period was not observed due to chronic renal failure that started in the neonatal period.

반복하중을 받는 고강도 철근콘크리트 보의 전단피로 거동 (Shear-Fatigue Behavior of High-Strength Reinforced Concrete Beams under Repeated Loading)

  • 곽계환
    • 한국농공학회지
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    • 제41권4호
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    • pp.92-103
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    • 1999
  • Recently structural damage has been frequently observed in reinforced concrete brdiges due to repeated loads such as vehicular traffic an due to continual overloads by heavy duty trucks. Therefore, the purpose of this experimental stduy is to investigate the damage mechanism due to fatigue behavior of high-strength reinforced concrete beams under repeated loads. From the test results, the relation of cycle loading to deflection is on the mid-span , the crack growth and the modes of failure according to cycle number, fatigue life and S-N curve were observed through the fatigue test. Based on the fatigue test results , high-strength reinforced concrete beams failed to 57 ∼66 percent of the static ultimate strength . Fatigue strength aobut two million cycles from S-N curves was certified by 60 percent of static ultimate strength.

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Laser CVD법에 의한 평탄화 층간 절연막 형성에 관한 연구 (A Study on Planarized Formation of Inter-Level Dielectric Films by Laser CVD Method)

  • 이계신;박근영;이한신;홍성훈;허윤종;성영권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.1271-1273
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    • 1993
  • $SiO_2$ and SiON films are formed by Laser CVD for inter-level dielectrics in submicron VLSI. This technique is noticeable that film formation can be done at low temperatures, below $300^{\circ}C$ with less damage. An ArF Excimer Laser with wave length of 193nm is used to excite and dissociate reactant gases. After film formation growth rate, refractive index, I-V curve, and step coverage characteristics of the films were evaluated.

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CaSki 세포주에서 성장 상태에 따른 X-선에 의한 c-jun의 발현 (Expression of c-jun by X-ray According to Cell Growth State in CaSki Cell Line)

  • 장성순;박우윤
    • Radiation Oncology Journal
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    • 제17권3호
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    • pp.223-229
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    • 1999
  • 목적 : 세포의 성장 상태 즉, 지수적 증식기와 평형기 세포에서 방사선에 의한 c-jun의 발현 양상의 차이를 파악하고, 방사선조사 후 세포주기 분포를 분석하여 이들의 상관 관계를 알아보고자 하였다. 대상 및 방법 : 사람 자궁경부암 세포주인 CaSki를 대상으로 날자 경과에 따른 세포성장곡선을 작성하여 지수적 증식기(제 4일)와 평형기(제 9일) 세포를 정하였다. 방사선조사는 6 MV 선형가속기를 이용해 2 Gy의 선량을 조사하였고, 이때 선량률은 3 Gy/min 이었다. 지수적 증식기와 평형기 세포 각각에 방사선조사 후 시간 경과에 따라 total RNA를 추출하여 northern blot analysis를 시행해 c-jun의 발현 양상을 관찰하였다. 또 방사선조사 후 시간 경과에 따라 세포를 얻어 유세포계측법을 이용해 세포주기 분포를 분석하였다. 결과 : 방사선조사 1 시간 후에 지수적 증식기와 평형기 세포 모두에서 최대의 발현이 관찰되었다. 그러나 이후 6시간까지 지수적 증식기 세포에서는 지속적으로 발현이 증가한 반면, 평형기에서는 점차 발현이 감소되는 양상을 보였다. 방사선에 의한 세포주기의 변화는 지수적 증식기에서 시간 경과에 따라 G0-G1에서 S, G2-M 기로의 이동이 더 활발히 일어났다. 결론 : c-jun 은 방사선조사 후 성장상태에 따른 세포 증식의 조절과 관련 있을 것이다.

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다학제 분야 학술지의 주제어 동시발생 네트워크를 활용한 기술예측 연구 (A Study on Technology Forecasting based on Co-occurrence Network of Keyword in Multidisciplinary Journals)

  • 김현욱;안상진;정우성
    • 한국경영과학회지
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    • 제40권4호
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    • pp.49-63
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    • 2015
  • Keyword indexed in multidisciplinary journals show trends about science and technology innovation. Nature and Science were selected as multidisciplinary journals for our analysis. In order to reduce the effect of plurality of keyword, stemming algorithm were implemented. After this process, we fitted growth curve of keyword (stem) following bass model, which is a well-known model in diffusion process. Bass model is useful for expressing growth pattern by assuming innovative and imitative activities in innovation spreading. In addition, we construct keyword co-occurrence network and calculate network measures such as centrality indices and local clustering coefficient. Based on network metrics and yearly frequency of keyword, time series analysis was conducted for obtaining statistical causality between these measures. For some cases, local clustering coefficient seems to Granger-cause yearly frequency of keyword. We expect that local clustering coefficient could be a supportive indicator of emerging science and technology.