• 제목/요약/키워드: average strain

검색결과 693건 처리시간 0.034초

Experimental In-Vivo Models Used in Fat Grafting Research for Volume Augmentation in Soft Tissue Reconstruction

  • Lujan-Hernandez, Jorge;Appasani, Raghu;Sullivan, Kylee;Siegel-Reamer, Leah;Lalikos, Janice F.
    • Archives of Plastic Surgery
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    • 제44권5호
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    • pp.361-369
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    • 2017
  • As the popularity of fat grafting research increases, animal models are being used as the source of pre-clinical experimental information for discovery and to enhance techniques. To date, animal models used in this research have not been compared to provide a standardized model. We analyzed publications from 1968-2015 to compare published accounts of animal models in fat grafting research. Data collected included: species used, graft characteristics (donor tissue, recipient area, amount injected, injection technique), time of sacrifice and quantification methods. Mice were most commonly used (56% of studies), with the "athymic nude" strain utilized most frequently (44%). Autologous fat was the most common source of grafted tissue (52%). Subcutaneous dorsum was the most common recipient site (51%). On average, $0.80{\pm}0.60mL$ of fat was grafted. A single bolus technique was used in 57% of studies. Fat volume assessment was typically completed at the end of the study, occurring at less than 1 week to one year. Graft volume was quantified by weight (63%), usually in conjunction with another analysis. The results demonstrate the current heterogeneity of animal models in this research. We propose that the research community reach a consensus to allow better comparison of techniques and results. One example is the model used in our laboratory and others; this model is described in detail. Eventually, larger animal models may better translate to the human condition but, given increased financial costs and animal facility capability, should be explored when data obtained from small animal studies is exhausted or inconclusive.

유산균의 첨가 급여가 산란 생산성, 소화기관 미생물 변화 및 계란 품질에 미치는 영향 (Effect of Supplmental Lactobacillus on Laying Performance, Intestinal Microflora and Egg Quality)

  • 김상호;박수영;유동조;이상진;강보석;최철환;류경선
    • 한국가금학회지
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    • 제27권3호
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    • pp.235-242
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    • 2000
  • A feeding trial was carried out effect of supplemental Lactobacillus on productivity, egg quality and intestinal microflora in 320 21 weeks - old laying hens for 12 week. Supplemented Lactobacillus strains were Lactobacillus amylovorus LLA7(LA), Lactobacillus crispatus LLA9(LC) and Lactobacillus vaginalis LLA11(LV). Three strains mixed to basal diet which containing 2,800㎉/kg ME, 16% CP with none, LA, LC, LV, LA+LC, LA+LV, LC+LV and LC+LC+LV. Supplemental level was 10(sup)7 cfu/g diet. Egg production was tended to increase with adding Lactobacilus, but not difference significantly. Average egg weight was heavier in adding Lactobacillrs compared to the none, and heaviest in LA+LV, LC+LV(P〈0.05). In periodic observation, the gap of egg weight with adding Lactobacillus or not was severe persisting laying periods. The diet containg MC or LV was better than LA, which means the difference by Lactobacillus strains for egg weight. Daily egg mass also increased in adding Lactobacillus about 1.1 to 2.3 g/hen, but not difference significantly. Feed intake and feed conversion were not difference regardless Lactobacillus strains and laying periods. Haugh unit improved with adding Lactobacillus. Cecal Lactobacillus spp. was increased with adding Lactobacillus(P〈0.05), didn't observed E. coli depression. In summary, supplemental Lactobacillus could improve for egg production, egg weight, egg mass and egg white. And those of effect expect much beneficial with mixing Lactobacillus which established well as single strain.

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수도권 상수중 유기오염물질의 돌연변이원성 (Mutagenic Activity of Organic Pollutans in Drinking Water in Seoul)

  • 신동천;장재연;조성준;정용
    • Journal of Preventive Medicine and Public Health
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    • 제21권2호
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    • pp.284-294
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    • 1988
  • To measure the mutagenic activity of micro-organic pollutants in drinking water, mutagenicity test was conducted using Salmnella typhimurium TA 98 strain on the water sample taken from three water supply stations and six tap water in Seoul in July and November 1987. The results were as follows : 1. The average amounts of organic matters in raw, treated, and tap water sampled in July were 0.38mg/l, 0.28mg/l, and 0.45mg/l. respectively, and sampled in November were 0.34mg/l, 0.24mg/l, and 0.22mg/l, respectively. The amount of organic matters of tap water sampled in November did not increase while that of tap water sampled in July increased compare to those of raw or treated water. 2. The amount of organic matters is the highest in neutral fraction compare to acidic and basic fractions. 3. In the five out of six tap water and raw water of Paldang and Kuui station sampled in July, the mutagenicity ratios were greater then two (both direct and indirect mutagenicity). 4. In the three out of six tap water and raw and treated water of Kuui station sampled in November, the mutagenicity ratios were greater than two. 5. While mutagenic activities were low in acidic and basic fraction, they were high in neutral fraction. The samples which had high mutagenic acitivity in the total amount also showed high mutagenic activity in neutral fraction. 6. While mutagenic acitivity was decreased after the treatement of water, it was increased in tap water as the distance from the water supply station increases.

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박테리아 발광 특성을 이용한 고형시료 급성 독성법 연구 및 적용 (Development and Application of Acute Bioassay Method on Solid Samples using Bioluminescence Producing Bacteria)

  • 고경석;공인철;정홍경;노열
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제12권6호
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    • pp.46-52
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    • 2007
  • 생물 발광 생산 균주, Escherichia coli DH5 RB1436를 이용하여 고형환경 시료에 대한 독성 방법을 개발하고 적용하였다. 토양과 균주의 비율은 1 : 4(w/v) 정도가 적절하였으며, 측정 방법의 간편성을 고려하여 가열 감량된 토양 첨가군 대신에 동일한 부피의 인산염 완충액 첨가군을 고형시료 독성의 대조군으로 정하였다. 토양측정망 시료중 대체적으로 오염원 농도가 상대적으로 높은 그룹과 낮은 그룹의 독성은 각 43과 26%로 뚜렷한 차이를 나타내었다. 토양 그룹들의 $EC_{50}$는 범위가 $1.8{\sim}4.6\;g$으로 조사된 반면에, 댐저수지 퇴적물과 매립물들은 모두 0.22 g 보다 낮게 조사되었다. 상이한 고형환경 시료에 대해 뚜렷한 독성 차이를 나타낸 본 생물검정법은 다양한 환경 시료의 독성을 평가하는 유용한 방법으로 사용할 수 있을 것이다.

Confinement models for high strength short square and rectangular concrete-filled steel tubular columns

  • Aslani, Farhad;Uy, Brian;Wang, Ziwen;Patel, Vipul
    • Steel and Composite Structures
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    • 제22권5호
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    • pp.937-974
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    • 2016
  • While extensive efforts have been made in the past to develop finite element models (FEMs) for concrete-filled steel tubular columns (CFSTCs), these models may not be suitable to be used in some cases, especially in view of the utilisation of high strength steel and high strength concrete. A method is presented herein to predict the complete stress-strain curve of concrete subjected to tri-axial compressive stresses caused by axial load coupled with lateral pressure due to the confinement action in square and rectangular CFSTCs with normal and high strength materials. To evaluate the lateral pressure exerted on the concrete in square and rectangular shaped columns, an accurately developed FEM which incorporates the effects of initial local imperfections and residual stresses using the commercial program ABAQUS is adopted. Subsequently, an extensive parametric study is conducted herein to propose an empirical equation for the maximum average lateral pressure, which depends on the material and geometric properties of the columns. The analysis parameters include the concrete compressive strength ($f^{\prime}_c=20-110N/mm^2$), steel yield strength ($f_y=220-850N/mm^2$), width-to-thickness (B/t) ratios in the range of 15-52, as well as the length-to-width (L/B) ratios in the range of 2-4. The predictions of the behaviour, ultimate axial strengths, and failure modes are compared with the available experimental results to verify the accuracy of the models developed. Furthermore, a design model is proposed for short square and rectangular CFSTCs. Additionally, comparisons with the prediction of axial load capacity by using the proposed design model, Australian Standard and Eurocode 4 code provisions for box composite columns are carried out.

The development of herbicide-resistant maize: stable Agrobacterium-mediated transformation of maize using explants of type II embryogenic calli

  • Kim, Hyun A.;Utomo, Setyo Dwi;Kwon, Suk Yoon;Min, Sung Ran;Kim, Jin Seog;Yoo, Han Sang;Choi, Pil Son
    • Plant Biotechnology Reports
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    • 제3권4호
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    • pp.277-283
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    • 2009
  • One of the limitations to conducting maize Agrobacterium-mediated transformation using explants of immature zygotic embryos routinely is the availability of the explants. To produce immature embryos routinely and continuously requires a well-equipped greenhouse and laborious artificial pollination. To overcome this limitation, an Agrobacterium-mediated transformation system using explants of type II embryogenic calli was developed. Once the type II embryogenic calli are produced, they can be subcultured and/or proliferated conveniently. The objectives of this study were to demonstrate a stable Agrobacterium-mediated transformation of maize using explants of type II embryonic calli and to evaluate the efficiency of the protocol in order to develop herbicide-resistant maize. The type II embryogenic calli were inoculated with Agrobacterium tumefaciens strain C58C1 carrying binary vector pTF102, and then were subsequently cultured on the following media: co-cultivation medium for 1 day, delay medium for 7 days, selection medium for $4{\times}14$ days, regeneration medium, and finally on germination medium. The T-DNA of the vector carried two cassettes (Ubi promoter-EPSPs ORF-nos and 35S promoter-bar ORF-nos). The EPSPs conferred resistance to glyphosate and bar conferred resistance to phosphinothricin. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to phosphinothricin indicated by the growth of putative transgenic calli on selection medium amended with $4mg\;1^{-1}$ phosphinothricin, northern blot analysis of bar gene, and leaf painting assay for detection of bar gene-based herbicide resistance. Northern blot analysis and leaf painting assay confirmed the expression of bar transgenes in the $R_1$ generation. The average transformation efficiency was 0.60%. Based on northern blot analysis and leaf painting assay, line 31 was selected as an elite line of maize resistant to herbicide.

유한요소해석기법을 이용한 토크 시편의 축 오열 영향 분석 (Effects of Axial Misalignments on the Torque Specimens Using Finite Element Analysis)

  • 김주희;김윤재;허용학
    • 대한기계학회논문집A
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    • 제35권11호
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    • pp.1461-1469
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    • 2011
  • 본 논문은 3 차원 유한요소해석 기법을 이용하여 토오크 시험을 위한 표준시험시편의 각도 및 동심 오열이 시편의 응력과 변형률 변화에 미치는 영향을 분석하였다. 해석 결과의 정량적 비교를 위해 각, 동심 및 복합 축 오열에 대한 평균 굽힘 변형률을 적용하였으며, 시편 형상에 따른 축 오열 영향을 확인하기 위해 환봉형 시편과 튜브형 시편에 대해 각각 유한요소해석을 실시하였다. 해석결과로부터 얻어진 변형률과 응력의 변화로 축 오열의 종류와 방향을 예측하는 일반적인 기준을 제시하였으며, 초기 항복조건을 적용하여 축 오열이 토오크 시편의 초기 항복 모멘트에 미치는 영향을 분석하였다.

투과전자현미경 조사에 의한 사파이어 $({\alpha}-Al_2O_3)$합성 결정내의 결함특성 분석 (Characterization of Defects in a Synthesized Crystal of Sapphire $({\alpha}-Al_2O_3)$ by TEM)

  • 김황수;송세안
    • Applied Microscopy
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    • 제36권3호
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    • pp.155-163
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    • 2006
  • 합성 사파이어 기판 시료-GaN반도체의 성장기판으로 사용된-의 내재하는 결함 형태를 전통적인 투과식 전자현미경 조사기법 (TEM), LACBED, HAADF-STEM 방법으로 관찰 분석하였다. 이 시료에서 주로 발견된 결함들은 두께 ${\sim}2nm$에서 32nm를 가진(0001)면 미소 쌍정(basal microtwins), 모체 결정과의 계면 주위의 변형 결함, (0001)면 전위결함(basal dislocations), 그리고 {$2\bar{1}\bar{1}3$} 피라미드 미끄럼면 중 한 면에서 일어나는 복잡한 형태의 전위 결함들이다 이들(0001)면 및 {$2\bar{1}\bar{1}3$}면에 전위 결함들은 미소 쌍정과 강하게 관련되어 일어나는 것으로 보인다. 또한 전위결함 밀도는 매우 균일하지 않으며 수 ${\mu}m$의 크기의 결함 밀집 영역에서는 그 밀도가 ${\sim}10^{10}/cm^2정도만큼 높지만 시료 전체에서의 평균은 대체적으로 ${\sim}10^5/cm^2보다 작다. 이 값은 보통 합성되는 결정에서 평균적으로 예상되는 수치이다.

Galactosamine에 의해 유도된 녹각추출물이 간장해에 미치는 영향 (The Effect of old Antler on the Galactosamine-induced Hepatotoxicity in Rate)

  • 김명주;박은미
    • 한국식품영양학회지
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    • 제9권4호
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    • pp.472-477
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    • 1996
  • 간장해에 미치는 녹각의 효과를 밝힐 목적으로 녹각을 성분별로 추출 분리하여 급여하고 galactosamine으로 간장해를 유도한 후 녹각추출물이 간기능 유지에 관여하는 효소활성 및 지질 대사에 미치는 영향을 생화학적 측면에서 고찰하였다. Cytochrome P-450은 녹각추출물 급여로 증가하였으며 갈락토사민 투여로 감소하였으나 neutral-ext.군에서 높은 증가를 보였다. Glutathione peroxidase 활성은 갈락토사민 투여로 감소하였으나, 녹각 추출물 급여로 활성이 증가하였다. 간조직의 글루타티올 함량은 녹각추출물 급여로 유의적 변동이 없었으며 갈락토사민 투여로 감소하였다. 과산화지질 함량은 대조군에 비해 각각의 녹각추출물 급여군에서 감소하여 특히 water-ext. 군에서 감소정도가 가장 현저하였다. 간조직중의 총 지방질, 총 콜레스테롤 및 트리글리세리드의 함량은 대조군에 비해 각각의 녹각추출물 급여군에서 감소하였으며, water-ext.군에서 가장 많이 하게 감소하였다. 이상의 결과로 미루어 볼 때 녹각의 water-ext.과 neutral-ext.에 함유되어 있는 성분이 간기능 유지에 관여하는 효소합성 증가를 통해 활성증가를 유도하고, 이로써 독성의 대사를 촉진시키므로 간독성을 예방할 수 있을 것으로 생각되며, 이와 같은 녹각추출물의 작용이 생체에 흡수되어진 xenobiotics의 해독작용과 연관될 것으로 생각된다.

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Effectiveness of Worksite Intervention on Stress Management: An Analytic Literature Review

  • Park Kyoung-Ok
    • 보건교육건강증진학회지
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    • 제21권4호
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    • pp.15-33
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    • 2004
  • With growing significance of psychological well-being in the worksite, the purpose of this analysis was to overview the empirical studies on worksite stress management and to identity the overall effect of worksite health promotion programs on stress management through meta-analysis. Literature retrieval was conducted on-line first in MEDLINE, EBSCOhost Academic Search Premier, and PSYCHINFO databases in public health, psychology, sociology, and human resource management areas. All studies written in English and published in the peer-reviewed journals during 1990 and 2002 were recruited. Key words used in literature retrieval were 'worksite,' 'intervention,' 'program,' 'work stress,' 'strain,' 'burnout,' 'management,' 'prevention,' 'education,' and 'health promotion.' A total of 18 worksite intervention studies with 48 effect sizes were analyzed and the results were as follows. Approximately 60% of the studies had quasi-experimental design and were conducted in manufacturing company and public sector. General psychological strains and burnout were frequently used measures of psychological stress. The lecturing and discussion typed intervention and the participatory problem-solving typed intervention were employed more than others in the studies. The average effect (r: pearson's simple correlation coefficient) weighted by sampling error was -0.14 (-0.32 to 0.05). In the conventional category of effects this is a small effect ranging from -0.59 to 0.05. Binomial effect size showed that success rates increased from 43% without intervention to 57% after an intervention. Sampling error explained 47.14% of the observed variance and its effectiveness on stress management were heterogeneous. In regression analysis with suspected moderating factors affecting the worksite interventions, research design was the only significant moderating factor. The studies with quasi-experimental design had greater effects than the studies with experimental design.