• Title/Summary/Keyword: analytical expression

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Direct Analysis in Real Time Mass Spectrometry (DART-MS) Analysis of Skin Metabolome Changes in the Ultraviolet B-Induced Mice

  • Park, Hye Min;Kim, Hye Jin;Jang, Young Pyo;Kim, Sun Yeou
    • Biomolecules & Therapeutics
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    • v.21 no.6
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    • pp.470-475
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    • 2013
  • Ultraviolet (UV) radiation is a major environmental factor that leads to acute and chronic reactions in the human skin. UV exposure induces wrinkle formation, DNA damage, and generation of reactive oxygen species (ROS). Most mechanistic studies of skin physiology and pharmacology related with UV-irradiated skin have focused on proteins and their related gene expression or single-targeted small molecules. The present study identified and analyzed the alteration of skin metabolites following UVB irradiation and topical retinyl palmitate (RP, 5%) treatment in hairless mice using direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) with multivariate analysis. Under the negative ion mode, the DART ion source successfully ionized various fatty acids including palmitoleic and linolenic acid. From DART-TOF-MS fingerprints measured in positive mode, the prominent dehydrated ion peak (m/z: 369, M+H-$H_2O$) of cholesterol was characterized in all three groups. In positive mode, the discrimination among three groups was much clearer than that in negative mode by using multivariate analysis of orthogonal partial-least squares-discriminant analysis (OPLS-DA). DART-TOF-MS can ionize various small organic molecules in living tissues and is an efficient alternative analytical tool for acquiring full chemical fingerprints from living tissues without requiring sample preparation. DART-MS measurement of skin tissue with multivariate analysis proved to be a powerful method to discriminate between experimental groups and to find biomarkers for various experiment models in skin dermatological research.

Disease Free Survival among Molecular Subtypes of Early Stage Breast Cancer between 2001 and 2010 in Iran

  • Najafi, Behrouz;Anvari, Saeid;Roshan, Zahra Atrkar
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5811-5816
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    • 2013
  • Background: Breast cancer is the most common cancer among women. Molecular subtypes are important in determining prognosis. This study evaluated five-year disease-free survival among four molecular subtypes in patients with early stages of breast cancer. Materials and Methods: In this retrospective descriptive-analytical study, information on patients with breast cancer between 2001-2010 was evaluated. Five hundred ninety two patients in the early stages of breast cancer (stages 1 and 2) were selected to undergo anthracycline-based chemotherapy. Relapse, death or absence (censor) were considered as the end of the study. Patients based on ER, PR and HER-2 expression were divided into four subtypes (luminal A, luminal B, HER-2 enriched and triple negative). Information based upon questionnaire was analysed. To show the patients survival rate, life table and Kaplan-Meyer methods were used, and for comparing mean survival among different groups, the Log-Rank test was utilized. Results: Mean age at diagnosis was $47.9{\pm}9.6$. Out of the 592 patients, 586 were female (99%) and 6 were male (1%). Considering breast cancer molecular subtypes, 361 patients were in the luminal A group (61%), 49 patients in the luminal B group (8.3%), 48 patients in the HER-2 enriched group (8.1%) and 134 in the triple negative group (22.6%). Mean disease-free survival was 53.7 months overall, 55.4 months for the luminal A group, 48.3 months for the luminal B group, 43 months for the HER-2enriched group and 54.6 months for the triple negatives. Disease free survival differed significantly among the molecular subtypes (p value=0.0001). Conclusions: The best disease-free survival rate was among the luminal A subgroup and the worst disease-free survival rate was among the HER-2 enriched subgroup. Disease free survival rate in the HER-2 positive groups (luminal B and HER-2 enriched) was worse than the HER-2 negative groups (luminal A and triple negative).

The Analytical Study on the Plural Eclecticism and the Aesthetic Characteristics through the Artwork of Vivienne Westwood (Vivienne Westwood 작품에 나타난 미적 특성과 다원적 절충주의 분석 연구)

  • Kim, Young-Sam;Bae, Jung-Min
    • The Research Journal of the Costume Culture
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    • v.14 no.4
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    • pp.657-669
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    • 2006
  • This study is to investigate the previous cases of plural eclecticism through the works of Vivienne Westwood, who contributed to the spread of innovative and eclectic English fashion out to the world as well as to review plurality and its phenomena since the 20th century more systematically. In terms of research methodology, the phenomena of plural eclecticism were examined from social and cultural perspectives, whereas bibliographic research and case study were performed for the phenomena of eclecticism in fashion. From the perspective of plural eclecticism, the results from analyzing the works of Vivienne Westwood by the divisions of temporal eclecticism, spatial eclecticism, and contingent eclecticism are described in the following. First, Vivienne Westwood emphasized historicism tendency of temporal eclecticism. Her efforts to try to modernize history went beyond ages and social classes including men's clothing, prostitutes' costumes, craft items, and dresses for royal family. Second, her spatial eclecticism was reflected on the first collection themes inspired by the American Indians or borrowed from the names of Voodoo in the Tropics. Finally, infra-fashion as an expression of contingent eclecticism of Vivienne Westwood's works can be interpreted as plural eclecticism which shows contingent eclecticism and historic eclecticism at the same time. This study aimed at proving preceding implications concerning recent plural eclecticism through the analysis of the works of Vivienne Westwood who tried a radical design of plural eclecticism in an effort to modernize the tradition of England in the circumstances where a number of trends and styles exist together, with their own uniqueness and values.

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A Square Root Normalized LMS Algorithm for Adaptive Identification with Non-Stationary Inputs

  • Alouane Monia Turki-Hadj
    • Journal of Communications and Networks
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    • v.9 no.1
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    • pp.18-27
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    • 2007
  • The conventional normalized least mean square (NLMS) algorithm is the most widely used for adaptive identification within a non-stationary input context. The convergence of the NLMS algorithm is independent of environmental changes. However, its steady state performance is impaired during input sequences with low dynamics. In this paper, we propose a new NLMS algorithm which is, in the steady state, insensitive to the time variations of the input dynamics. The square soot (SR)-NLMS algorithm is based on a normalization of the LMS adaptive filter input by the Euclidean norm of the tap-input. The tap-input power of the SR-NLMS adaptive filter is then equal to one even during sequences with low dynamics. Therefore, the amplification of the observation noise power by the tap-input power is cancelled in the misadjustment time evolution. The harmful effect of the low dynamics input sequences, on the steady state performance of the LMS adaptive filter are then reduced. In addition, the square root normalized input is more stationary than the base input. Therefore, the robustness of LMS adaptive filter with respect to the input non stationarity is enhanced. A performance analysis of the first- and the second-order statistic behavior of the proposed SR-NLMS adaptive filter is carried out. In particular, an analytical expression of the step size ensuring stability and mean convergence is derived. In addition, the results of an experimental study demonstrating the good performance of the SR-NLMS algorithm are given. A comparison of these results with those obtained from a standard NLMS algorithm, is performed. It is shown that, within a non-stationary input context, the SR-NLMS algorithm exhibits better performance than the NLMS algorithm.

Verification of Parameters Influencing Bond Strength between Fiber-Reinforced Polymer Laminates and Concrete (연속섬유(FRP)시트와 콘크리트의 부착강도 영향 요인 검증)

  • Ko, Hune-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.414-423
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    • 2020
  • Fiber-reinforced polymer (FRP) laminate sheets, which are lightweight with high strength, are commonly used to reinforce concrete structures. The bonding strength is vital in structural design. Therefore, experiments and analytical studies with differing variables (concrete compressive strength and tensile strength, the elastic modulus of concrete and FRP, thickness of concrete and FRP, width of concrete and FRP, bond length, effective bond length, fracture energy, maximum bond stress, maximum slip) have been conducted to obtain an accurate numerical model of the bond strength between an FRP sheet and concrete. Although many models have been proposed, no validated model has emerged that could be used easily in practice. Therefore, this study analyzed the parameters that influence the bond strength that were used in 23 of the proposed models (Khalifa model, Iso model, Maeda model, Chen model, etc.) and compared them to the test results of 188 specimens via the numerical results of each model. As a result, an easy-to-use practical model with a simple and high degree of expression was proposed based on the Iso model combined with the effective bond length model that was proposed by Holzenkӓmpfer.

Hemorheological measurements in experimental animals: further consideration of cell size - pore size relations in filtrometry

  • Nemeth, Norbert;Baskurt, Oguz K.;Meiselman, Herbert J.;Furka, Istvan;Miko, Iren
    • Korea-Australia Rheology Journal
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    • v.21 no.3
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    • pp.155-160
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    • 2009
  • Micropore filtration of dilute red blood cell (RBC) suspensions is a widely known method for determining red blood cell deformability. Use of this method for cells from various laboratory animal species does require considering the effects of the cell size to pore size ratio and of suspension hematocrit. In general, previous animal studies have utilized 5% hematocrit suspensions and five micron pores, and thus conditions similar to human clinical laboratory practice. However, when used for repeated sampling from small laboratory animals or for parallel multiple samples from different sites in large laboratory animals, the volume of blood sampled and hence the hematocrit of the test suspension may be limited. Our results indicate that hematocrit levels yielding stable values of RBC pore transit time are pore size and species specific: three micron pores = $2{\sim}5%$ for dog and $3{\sim}5%$ for rat; five micron pores $3{\sim}5%$ for dog and $1{\sim}5%$ for rat. An analytical approach using a common expression for calculating transit time is useful for determining the sensitivity of this time to hematocrit alterations and hence to indicate hematocrit levels that may be problematic.

Estimation of uncertainty for the determination of residual flubendazole in pork (돼지고기 중 플루벤다졸 잔류분석의 불확도 추정)

  • Kim, MeeKyung;Park, Su-Jeong;Lim, Chae-Mi;Cho, Byung-Hoon;Kwon, Hyun-Jeong;Kim, Dong-Gyu;Chung, Gab-Soo
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.139-145
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    • 2007
  • Measurement uncertainty could play an important role in the assessment of test results in laboratories and industries. We investigated measurement uncertainties possibly included in determination of flubendazole, a benzimidazole anthelmintic, in pork by HPLC. The concentration of flubendazole was 62.69 ng/g in a sample of pork. Uncertainty was estimated in the analytical procedure of flubendazole. A model equation was made for determination of flubendazole in pork. The four uncertainty components such as weight of sample, volume of sample, calibration curve, and recovery were selected to estimate measurement uncertainties. Standard uncertainty was calculated for each component and all the standard uncertainties were combined. The combined standard uncertainty was expanded to a sample population as an expanded uncertainty. The expanded uncertainty was calculated using k value on Student's t-table and effective degrees of freedom from Welch-Satterthwaite formula. The expanded uncertainty was calculated as 3.45 with the combined standard uncertainty, 1.584 6 and the k value, 2.18. The final expression can be ($62.69{\pm}3.45$) ng/g (confidence level 95%, k = 2.18). The uncertainty value might be estimated differently depending on the selection of the uncertainty components. It is difficult to estimate all the uncertainty factors. Therefore, it is better to take several big effecting components instead of many small effecting components.

Screening of Anti-cancer Compounds Originated from Filamentous Fungi (Monascus sp.) (사상성 곰팡이 (Monascus sp.) 유래 항암 물질의 탐색)

  • Sin, Yeong-Min;Park, Hae-Ryoun;An, Won-Gun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.3
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    • pp.671-676
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    • 2005
  • In this study, we investigated the antioxidant effect of extract from Monascus pillosus, on the human wild-type p53 and p21 expressing A549 lung epithelial cell line and MCF-7 mammary adenocarcinoma cell line stimulated by NO. $P21^{waf/cip1}$ was identified as a gene induced in senescent cells. It is a cyclin-dependent kinase inhibitor and has been shown to cause cell cycle arrest and apoptosis. While p53-regulated stimulation of p21 appears to be central for the permanent growth-arrest, the role of p21 in p53-triggered cell death is unclear. Low dose of sodium nitroprusside (SNP) induced the development of senescence associated with increased expression of p53 and p21 in A549 cells. Inhibition of p21 transactivating activity requires high level correlates with the amount of p53 necessary to cause cell death. Association of p21 and p53 results in inhibition of p21-stimulated transcription. This requires a higher p53 level than is necessary for transcriptional activation of endogenous p53-responsive gene but correlates well with the level of p53 necessary to cause cell death. Exposure to W-1 inhibited oxidative stresses-induced senescence-like arrest, resulting in a significant reduction in p53 and p21 steady state levels. These results suggest that p53 and p21 play a central role in the onset of senescence. Thus, it is important to emphasize control of oxidative balance in tumor prevention and aging.

Quantitative Phosphoproteomics of the Human Neural Stem Cell Differentiation into Oligodendrocyte by Mass Spectrometry

  • Cho, Kun;Kim, Jin Young;Kim, Eunmin;Park, Gun Wook;Kang, Tae Wook;Yoon, Jung Hae;Kim, Seung U.;Byun, Kyunghee;Lee, Bonghee;Yoo, Jong Shin
    • Mass Spectrometry Letters
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    • v.3 no.4
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    • pp.93-100
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    • 2012
  • Cellular processes such as proliferation, differentiation, and adaptation to environmental changes are regulated by protein phosphorylation. In order to enhance the understanding of molecular dynamics for biological process in detail, it is necessary to develop sensitive and comprehensive analytical methods for the determination of protein phosphorylation. Neural stem cells hold great promise for neural repair following an injury or disease. In this study, we made differentiated oligodendrocytes from human neural stem cells using over-expression of olig2 gene. We confirmed using quantitative phosphoproteome analysis approach that combines stable isotope labeling by amino acids in cell culture (SILAC) and $TiO_2$ micro-column for phosphopeptide enrichment with $MS^2$ and $MS^3$ mass spectrometry. We detected 275 phosphopeptides which were modulated at least 2-fold between human neural stem cells and oligodendrocytes. Among them, 23 phosphoproteins were up-regulated in oligodendrocytes and 79 phosphoproteins were up-regulated in F3 cells.

An analytical study on the heat transfer of the laminar filmwise condensation on a vertical surface (수직평판에서 층류막상 응축열전달에 관한 해석적 고찰)

  • 김형섭
    • Journal of the korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.21-31
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    • 1980
  • Two phase boundary layer equations of laminar filmwise condensation are solved by an approximate integral method under the following condition; saturated vapour flows vertically downward over a cooled surface of uniform temperature, the condensate film is so thin that the inertia and convection terms are neglected. The following conclusions are drawn under the above assumptions. 1. free convection In case of the linear temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$=4/3,(G $r_{l}$ /4.H)$^{1}$4/ and in case of the quadratic profile, numerical results may be expressed as N $u_{m}$=2/1.682,(G $r_{l}$ /H)$^{1}$4/. 2. Forced convection When the temperature profile is assumed to be linear in a liquid film, numerical results fir the average heat transfer coefficients may be expressed as N $u_{m}$=(A, R $e_{l}$ /H)$^{1}$2/. This expression is compared with the experimental results hitherto reported; For theoretical Nusselt number (N $u_{m}$)$_{th}$<2*10$^{4}$, the experimental Nusselt number (N $u_{m}$)$_{exp}$ is on the average larger than theoretical Nusselt number (N $u_{m}$)$_{th}$ by 30%. For (N $u_{m}$)$_{th}$>2*10$^{4}$, experimental Nusselt number (N $u_{m}$)$_{exp}$ is about 1.6 times as large as theoretical Nusselt number (N $u_{m}$)$_{th}$. These large deviation may be caused by the presence of turbulence in the liquid film. In case of the quadratic temperature profile in a liquid film, numerical results for the average coefficients of heat transfer may be expressed as N $u_{m}$'=(2,A,Re/H)$^{1}$2/. This formular shows that theoretical Nusselt number (N $u_{m}$)$_{th}$ is larger than experimental Nusselt number (N $u_{m}$)$_{exp}$ by 60%. It is speculated that when the temperature difference between cooled surface and saturated vapour is small, temperature profile in a liquid film is quadratic.quadratic.. quadratic.quadratic..atic..

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