• 제목/요약/키워드: C(t) - $A_2(t)$ approach

검색결과 167건 처리시간 0.026초

Crack-tip constraint analysis of two collinear cracks under creep condition

  • Jiao, Guang-Chen;Wang, Wei-Zhe;Jiang, Pu-Ning
    • Structural Engineering and Mechanics
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    • 제43권3호
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    • pp.311-320
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    • 2012
  • The higher-order asymptotic C(t) - $A_2(t)$ approach was employed to investigate the crack-tip stress of two collinear cracks in a power-law creeping material under the plane strain conditions. A comprehensive calculation was made of the single crack, collinear crack model with S/a = 0.4 and 0.8, by using the C(t) - $A_2(t)$ approach, HRR-type field and the finite element analysis; the latter two methods were used to check the constraint significance and the calculation accuracy of the C(t) - $A_2(t)$ approach, respectively. With increasing the creep time, the constraint $A_2$ was exponentially increased in the small-scale creep stage, while no discernible dependency of the constraint $A_2$ on the creep time was found at the extensive creep state. In addition, the creep time and the mechanical loads have no distinct influence on accuracy of the results obtained from the higher-order asymptotic C(t) - $A_2(t)$ approach. In comparison with the HRR-type field, the higher-order asymptotic C(t) - $A_2(t)$ solution matches well with the finite element results for the collinear crack model.

SINGULAR THIRD-ORDER 3-POINT BOUNDARY VALUE PROBLEMS

  • Palamides, Alex P.
    • Journal of applied mathematics & informatics
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    • 제28권3_4호
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    • pp.697-710
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    • 2010
  • In this paper, we prove existence of infinitely many positive and concave solutions, by means of a simple approach, to $3^{th}$ order three-point singular boundary value problem {$x^{\prime\prime\prime}(t)=\alpha(t)f(t,x(t))$, 0 < t < 1, $x(0)=x'(\eta)=x^{\prime\prime}(1)=0$, (1/2 < $\eta$ < 1). Moreover with respect to multiplicity of solutions, we don't assume any monotonicity on the nonlinearity. We rely on a combination of the analysis of the corresponding vector field on the phase-space along with Knesser's type properties of the solutions funnel and the well-known Krasnosel'ski$\breve{i}$'s fixed point theorem. The later is applied on a new very simple cone K, just on the plane $R^2$. These extensions justify the efficiency of our new approach compared to the commonly used one, where the cone $K\;{\subset}\;C$ ([0, 1], $\mathbb{R}$) and the existence of a positive Green's function is a necessity.

Caulobacter ginsengisoli sp. nov., a Novel Stalked Bacterium Isolated from Ginseng Cultivating Soil

  • Liu, Qing-Mei;Ten, Leonid N.;Im, Wan-Taek;Lee, Sung-Taik;Yoon, Min-Ho
    • Journal of Microbiology and Biotechnology
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    • 제20권1호
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    • pp.15-20
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    • 2010
  • A Gram negative, aerobic, nonspore-forming, straight or curved rod-shaped bacterium, designated Gsoil $317^T$, was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized using a polyphasic approach. Cells were dimorphic, with stalk (or prostheca) and nonmotile or nonstalked and motile, by means of a single polar flagellum. Comparative analysis of 16S rRNA gene sequences revealed that strain Gsoil $317^T$ was most closely related to Caulobacter mirabilis LMG $24261^T$ (97.2%), Caulobacter fusiformis ATCC $15257^T$ (97.1 %), Caulobacter segnis LMG $17158^T$ (97.0%), Caulobacter vibrioides DSM $9893^T$ (96.8%), and Caulobacter henricii ATCC $15253^T$ (96.7%). The sequence similarities to any other recognized species within Alphaproteobacteria were less than 96.0%. The detection of Q-10 as the major respiratory quinone and a fatty acid profile with summed feature 7 ($C_{18:1}\;{\omega}7c$ and/or $C_{18:1}\;{\omega}9t$ and/or $C_{18:1}\;{\omega}12t;$ 56.6%) and $C_{16:0}$ (15.9%) as the major fatty acids supported the affiliation of strain Gsoil $317^T$ to the genus Caulobacter. The G+C content of the genomic DNA was 65.5 mol%. DNA-DNA hybridization experiments showed that the DNA-DNA relatedness values between strain Gsoil $317^T$ and its closest phylogenetic neighbors were below 11%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil $317^T$ should be classified as representing a novel species in the genus Caulobacter, for which the name Caulobacter ginsengisoli sp. novo is proposed. The type strain is Gsoil $317^T$ (=KCTC $12788^T=DSM\;18695^T$).

Rheinheimera aquatica sp. nov., Antimicrobial Activity-Producing Bacterium Isolated from Freshwater Culture Pond

  • Chen, Wen-Ming;Lin, Chang-Yi;Young, Chiu-Chung;Sheu, Shih-Yi
    • Journal of Microbiology and Biotechnology
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    • 제20권10호
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    • pp.1386-1392
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    • 2010
  • A bacterial strain designated GR5$^T$, previously isolated from a freshwater culture pond in Taiwan while screening for bacteria for antimicrobial compounds, was characterized using a polyphasic taxonomic approach. Strain GR5$^T$ was found to be Gram-negative, aerobic, greenish-yellow colored, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at $10-40^{\circ}C$ (optimum, $35^{\circ}C$), pH 7.0-8.0 (optimum pH 8.0), and with 0-2.0% NaCl (optimum, 0.5-1.0%). The major fatty acids were $C_{16:1}{\omega}7c$(36.3%), $C_{16:0}$(16.6%), $C_{12:0}$ 3-OH (12.5%), and $C_{18:1}{\omega}7c$(9.1%). The major respiratory quinone was Q-8, and the DNA G+C content of the genomic DNA was 51.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GR5$^T$ belongs to the genus Rheinheimera, where its most closely related neighbors are Rheinheimera texasensis A62-14B$^T$ and Rheinheimera tangshanensis JA3-B52$^T$ with sequence similarities of 98.1% and 97.5%, respectively, and the sequence similarities to any other recognized species within Gammaproteobacteria are less than 96.5%. The mean level of DNA-DNA relatedness between strain GR5$^T$ and R. texasensis A62-14B$^T$, the strain most closely related to the isolate, was $26.5{\pm}7.6%$. Therefore, based on the phylogenetic and phenotypic data, strain GR5$^T$ should be classified as a novel species, for which the name Rheinheimera aquatica sp. nov. is proposed. The type strain is GR5$^T$ (=BCRC 80081$^T$=LMG 25379$^T$).

항원수용체자극에 의한 Cytolytic T cell 특이전사체 표현유도 (Antigen Receptor-Mediated Induction of Cytolytic T cell-Specific Transcripts Expression)

  • 김관식;;권병세
    • 대한약리학회지
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    • 제23권1호
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    • pp.45-49
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    • 1987
  • Cytolytic T cell(CTL)에서는 표현되나 다른 세포에서는 표현되지 않는 유전자를 검색하여 최근 저자는 3종의 CTL 특이 cDNA를 cloning하였다. CTL 특이 cDNA의 기능을 규명하기 위하여 CTL L3 cell을 항원수용체를 통하여 혹은 interleukin 2(IL-2)로 자극하여 활성화시킨 후 RNA blot analysis로 각 cDNA clone의 상응전사체 표현양상을 관찰, CTL활성화과정과의 연관성을 실험하였다. 이중 2종의 cDNA상응전사체표현은 항원수용체자극에 의해 현저히 증가된 반면 IL-2는 전혀 영향을 미치지 않았으며 이 같은 전사체표현증가는 cyclosporin A 처리로 완전히 억제되었다. 이상의 결과는 항원수용체자극으로 활성화되는 유전자가 IL-2에 의해 활성화되는 유전자와는 상이함을 보여주는 것이며 또한 2종의 cDNA clone이 IL-2에 의해 활성화되지 않으나 항원수용체를 통하여 중개되며 cyclosporin A에 예민하게 반응하는 CTL활성화과정의 특정경로에 관여하는 것으로 사료된다.

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Method for Assessing Forest Carbon Sinks by Ecological Process-Based Approach - A Case Study for Takayama Station, Japan

  • Lee, Mi-Sun
    • The Korean Journal of Ecology
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    • 제26권5호
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    • pp.289-296
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    • 2003
  • The ecological process-based approach provides a detailed assessment of belowground compartment as one of the major compartment of carbon balance. Carbon net balance (NEP: net ecosystem production) in forest ecosystems by ecological process-based approach is determined by the balance between net primary production (NPP) of vegetation and heterotrophic respiration (HR) of soil (NEP=NPP-HR). Respiration due to soil heterotrophs is the difference between total soil respiration (SR) and root respiration (RR) (HR=SR-RR, NEP=NPP-(SR-RR)). If NEP is positive, it is a sink of carbon. This study assessed the forest carbon balance by ecological process-based approach included belowground compartment intensively. The case study in the Takayama Station, cool-temperate deciduous broad-leaved forest was reported. From the result, NEP was estimated approximately 1.2 t C $ha^{-1} yr^{-1}$ in 1996. Therefore, the study area as a whole was estimated to act as a sink of carbon. According to flux tower result, the net uptake rate of carbon was 1.1 t C $ha^{-1} yr^{-1}$.

Sphingobacterium composti sp. nov., a Novel DNase-Producing Bacterium Isolated from Compost

  • Ten Leonid N.;Liu, Qing-Mei;Im Wan-Taek;Aslam Zubair;Lee, Sung-Taik
    • Journal of Microbiology and Biotechnology
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    • 제16권11호
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    • pp.1728-1733
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    • 2006
  • A Gram-negative, strictly aerobic, nonmotile, and nonspore-forming bacterial strain, designated $T5-12^T$, was isolated from compost and characterized using a polyphasic taxonomical approach. The isolate was positive for catalase and oxidase tests. It could degrade DNA, but was negative for degradation of macromolecules such as casein, collagen, starch, chitin, cellulose, and xylan. The DNA G+C content was 36.0 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were $iso-C_{15:0}$ (45.6%), $iso-C_{17:0}$ 3OH (17.2%), and summed feature 4 ($C_{16:0}\;{\omega}7c$ and/or $iso-C_{15:0}$ 2OH, 14.9%). Comparative 16S rRNA gene sequence analysis showed that strain $T5-12^T$ fell within the radiation of the cluster comprising members of the genus Sphingobacterium. Strain $T5-12^T$ exhibited lower than 94% of 16S rRNA gene sequence similarity with respect to the type strains of recognized Sphingobacterium species. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain $T5-12^T$ ($=KCTC\;12578^T=LMG\;23401^T=CCUG\;52467^T$) should be classified in the genus Sphingobacterium as the type strain of a novel species, for which the name Sphingobacterium composti sp. novo is proposed.

4-(Tert-butyl)-2,6-bis(1-phenylethyl)phenol induces pro-apoptotic activity

  • Kim, Jun Ho;Lee, Yunmi;Kim, Mi-Yeon;Cho, Jae Youl
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권3호
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    • pp.253-259
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    • 2016
  • Previously, we found that KTH-13 isolated from the butanol fraction of Cordyceps bassiana (Cb-BF) displayed anti-cancer activity. To improve its antiproliferative activity and production yield, we employed a total synthetic approach and derivatized KTH-13 to obtain chemical analogs. In this study, one KTH-13 derivative, 4-(tert-butyl)-2,6-bis(1-phenylethyl)phenol (KTH-13-t-Bu), was selected to test its anti-cancer activity. KTH-13-t-Bu diminished the proliferation of C6 glioma, MDA-MB-231, LoVo, and HCT-15 cells. KTH-13-t-Bu induced morphological changes in C6 glioma cells in a dose-dependent manner. KTH-13-t-Bu also increased the level of early apoptotic cells stained with annexin V-FITC. Furthermore, KTH-13-t-Bu increased the levels of cleaved caspase-3 and -9. In contrast, KTH-13-t-Bu upregulated the levels of pro- and cleaved forms of caspase-3, -8, and -9 and Bcl- 2. Phospho-STAT3, phospho-Src, and phospho-AKT levels were also diminished by KTH13-t-Bu treatment. Therefore, these results strongly suggest that KTH-13-t-Bu can be considered a novel anti-cancer drug displaying pro-apoptotic activity.

귀비탕(歸脾湯), 가미온담탕(加味溫膽湯) 및 귀비온담탕(歸脾溫膽湯)의 항(抗) Stress 효능(效能) 비교연구(比較硏究) (A study of the comparative effect of Kuibitang, Kamiondarmtang, and Kuibiondarmtang on serum levels in rats under the immobilization stress.)

  • 김형철;정대규
    • 동의신경정신과학회지
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    • 제4권1호
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    • pp.99-119
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    • 1993
  • In order to compare and examine the effect the effect of Kuibitang, Kamiondarmtang and Kuibiondarmtang against stress, I induced immobilization stress by binding rats for 200mins under a little anesthetized with ether. I classified as normal group, control group which administrated 0.9% NaCl solution, sample A group which administrated Kuibitang, sample B group which administrated Kamiondarmtang and sample C group which administrated Kuibiondarmtang. I got some conclusions by measuring amounts of norepinephrine, epinephrine, triiodothyronine($T_3$) and thyroxine($T_4$) in 1, 3 and 5 days, respectively. 1. Norepinephrine showed high meaningful decrease after 1. 3 and 5 days in sample A group. It showed little decrease in sample B group. It showed a little meaningful decrease after 1 day and high meaningful decrease after 3 and 5 days in sample C group. 2. Epinephrine showed high meaningful decrease after 3 and 5 days in sample A group. It showed little decrease in sample B group. It showed a little meaningful decrease after 3 days and high meaningful decrese after 5 days in sample C group. 3. Triiodothyronine($T_3$) inclined to approach normal value in sample A, B, C group in comparision wit control group but didn't have high meaning. 4. Thyroxine($T_4$) inclined to approach normal va1ue in sample A, B, C group in comparision with contrl group but didn't have high meaning. As I consider the effect of experiments, I think that Kuibitang and Kuibiondarmtang have some effects against stress and it is right to apply to the treatment of stress.

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인지체조-뉴로피드백을 활용한 통합 간호의 효과 (The Effect of Integrated Nursing using Cognicise and Neurofeedback)

  • 원희욱;허계영;김준범;신지은;이원우;손해경
    • 한국직업건강간호학회지
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    • 제29권2호
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    • pp.114-122
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    • 2020
  • Purpose: This study aimed to identify the effect of integrated nursing using cognicise and neurofeedback on cognition and α waves among elderly individuals. Methods: This quasi-experimental single group pretest-posttest study included 29 Korean adults aged 65 years or older who participated at a senior welfare center in Y city from February to May 2019. Each integrated nursing session consisted of cognicise (10 minutes) and neurofeedback (20 minutes). Subjects participated twice a week for 10 weeks. Structured questionnaires to assess participants' general characteristics and the Korean version of the Mini-Mental Status Examination for Dementia Screening (K-MMSE-DS) were applied. Alpha waves were measured using BrainMaster. Results: Following the integrated nursing program, alpha waves improved in F3 (t=2.41, p=.023), C3 (t=3.00, p=.006), C4 (t=2.60, p=.015), P3 (t=2.43, p=.022), O1 (t=2.30, p=.029), T3 (t=3.05, p=.005), T4 (t=2.28, p=.030), T5 (t=2.91, p=.007), Fz (t=2.30, p=.029), Cz (t=2.73, p=.011), and Pz (t=2.23, p=.034). Most subjects experienced improvement in concentration after participating in the intervention. Conclusion: This study provides evidence for the use of a neuroscientific approach including brain wave measurement to improve cognitive health among community-living elderly people.