• Title/Summary/Keyword: PSE

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Compressible Boundary Layer Stability Analysis With Parabolized Stability Equations

  • Bing, Gao;Park, S.O.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.110-119
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    • 2006
  • An accurate and cost efficient method PSE is used for the stability analysis of 2D or 3D compressible boundary layers. A highly accurate finite difference PSE code has been developed at a general curvilinear coordinate system using an implicit marching procedure to deal with a broad range of transition predictions problems. Evolution of disturbances in compressible flat plate boundary layers are studied for free-stream Mach numbers ranging from 0 to 1.5. The effect of mean-flow nonparallelism is found to be weak on two dimensional waves and strong on three dimensional waves. The maximum amplification rate increases monotonically with Mach number. The present PSE solutions are compared with previous numerical investigations and experimental results and are found to be in good agreement.

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Comparison of Postmortem Meat Quality and Consumer Sensory Characteristic Evaluations, According to Porcine Quality Classification

  • Nam, Yun-Ju;Choi, Young-Min;Jeong, Da-Woon;Kim, Byoung-Chul
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.307-311
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    • 2009
  • This study examined variations in postmortem meat quality characteristics and consumer sensory evaluations of different pork quality classes in fresh and cooked meat. Pale, soft, and exudative (PSE) meat had the highest drip loss, lightness, and the lowest $pH_{24\;hr}$ whereas dark, firm, and dry (DFD) meat showed the opposite results. When the fresh meat was evaluated by consumer panelists, they could only distinguish the PSE class of meat and it scored lowest in overall acceptability. However, the panelists did not consider cooked PSE or DFD pork to be unacceptable overall, indicating that consumers cannot distinguish the quality of cooked pork.

Diagnosis of Pigs Producing PSE Meat using DNA Analysis (DNA검사기법을 이용한 PSE 돈육 생산 돼지 진단)

  • Chung Eui-Ryong;Chung Ku-Young
    • Food Science of Animal Resources
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    • v.24 no.4
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    • pp.349-354
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    • 2004
  • Stress-susceptible pigs have been known as the porcine stress syndrome (PSS), swine PSS, also known as malignant hyperthermia (MH), is characterized as sudden death and production of poor meat quality such as PSE (pale, soft and exudative) meat after slaughtering. PSS and PSE meat cause major economic losses in the pig industry. A point mutation in the gene coding for the ryanodine receptor (RYR1) in porcine skeletal muscle, also known calcium (Ca$^{2+}$) release channel, has been associated with swine PSS and halothane sensitivity. We used the PCR-RFLP(restriction fragment length polymorphism) and PCR-SSCP (single strand conformation polymorphism) methods to detect the PSS gene mutation (C1843T) in the RYR1 gene and to estimate genotype frequencies of PSS gene in Korean pig breed populations. In PCR-RFLP and SSCP analyses, three genotypes of homozygous normal (N/M), heterozygous carrier (N/n) and homozygous recessive mutant (n/n) were detected using agarose or polyacrylamide gel electrophoresis, respectively. The proportions of normal, carrier and PSS pigs were 57.1, 35.7 and 7.1% for Landrace, 82.5, 15.8 and 1.7% far L. Yorkshire, 95.2, 4.8 and 0.0% for Duroc and 72.0, 22.7 and 5.3% for Crossbreed. Consequently, DNA-based diagnosis for the identification of stress-susceptible pigs of PSS and pigs producing PSE meat is a powerful technique. Especially, PCR-SSCP method may be useful as a rapid, sensitive and inexpensive test for the large-scale screening of PSS genotypes and pigs with PSE meat in the pork industry.y.

Objectively Predicting Ultimate Quality of Post-Rigor Pork Musculature: II. Practical Classification Method on the Cutting-Line

  • Joo, S.T.;Kauffman, R.G.;Warner, R.D.;Borggaard, C.;Stevenson-Barry, J.M.;Rhee, M.S.;Park, G.B.;Kim, B.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.1
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    • pp.77-85
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    • 2000
  • To investigate the practical assessing method of pork quality, 302 carcasses were selected randomly to represent commercial conditions and were probed at 24 hr postmortem (PM) by Danish Meat Quality Marbling (MQM), Hennessy Grading Probe (HGP), Sensoptic Resistance Probe (SRP) and NWK pH-K21 meter (NpH). Also, filter paper wetness (FPW), lightness (L*), ultimate pH (pHu), subjective color (SC), firmness/wetness (SF) and marbling scores (SM) were recorded. Each carcass was categorized as either PSE (pale, soft and exudative), RSE (Reddish-pink, soft and exudative), RFN (reddish-pink, firm and non-exudative) or DFD (dark, firm and dry). When discriminant analysis was used to sort carcasses into four quality groups the highest proportion of correct classes was 65% by HGP, 60% by MQM, 52% by NpH and 32% by SRP. When independent variables were combined to sort carcasses into groups the success was only 67%. When RSE and RFN groups were merged so that there were only three groups (PSE, RSE+RFN, DFD) differentiating by color MQM was able to sort the same set of data into the new set of three groups with 80% accuracy. The proportions of correct classifications for HGP, NpH and SRP were 75%, 61% and 35% respectively. There was a decline in predication accuracy when only two groups, exudative (PSE and RES) and non exudative (RFN and DFD) were sorted. However, when two groups designated PSE and non-PSE (RSE, RFN and DFD) were sorted then the proportion of correct classification by MQM, HGP, SRP and NpH were 87%, 81%, 71% and 66% respectively. Combinations of variables only increased the prediction accuracy by 1 or 2% over prediction by MQM alone. When the data was sorted into three marbling groups based on SM this was not well predicted by any of the probe measurements. The best prediction accuracy was 72% by a combination of MQM and NpH.

Antioxidant Activities of Perilla frutescens Britton Seed Extract and Its Inhibitory Effects against Major Characteristics of Cancer Cells (들깨 추출물의 항산화 활성과 암세포 기본 특성에 대한 억제 효과)

  • Kim, Sinae;Song, Boram;Ju, Jihyeung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.2
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    • pp.208-215
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    • 2015
  • The aim of the study was to investigate the antioxidant activities of ethanol extract of perilla seed (PSE) and its inhibitory effects against major characteristics of cancer cells, such as unrestricted growth and activated metastasis in vitro. The total polyphenol and flavonoid levels of PSE were 222.6 mg gallic acid equivalent/100 g and 285.7 mg quercetin equivalent/100 g, respectively. The radical scavenging activity and ferric reducing antioxidant power of PSE at concentration of 87.5 to $350{\mu}g/mL$ were 24~45% and 28~62%, respectively. Treatment of HCT116 colorectal carcinoma cells and H1299 non-small cell lung carcinoma cells with PSE dose-dependently inhibited growth by 18~94% (at concentration range of 87.5 to $350{\mu}g/mL$) and completely abolished colony formation (at concentration of $175{\mu}g/mL$). PSE was also effective in inhibiting migration of H1299 cells (by 30~37% at concentration range of 87.5 to $350{\mu}g/mL$) and adhesion of both HCT116 and H1299 cells (by 14~16% at concentration of $350{\mu}g/mL$). These results indicate that PSE exerts antioxidant and anti-cancer activities in vitro. It needs to be determined whether or not similar effects can be reproduced in vivo.

Protective Effect of Prunella spica Extracts against H2O2-Induced Cytotoxicity in PC12 Cells (Hydrogen peroxide가 유도하는 세포독성으로부터 PC12 세포를 보호하는 하고초(Prunella spica) 추출물의 영향)

  • Kim, Hyun-Jung;Lee, Jeung-Min;Moon, Seong-Hee;Park, Hae-Ryong
    • Journal of Life Science
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    • v.20 no.7
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    • pp.1121-1126
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    • 2010
  • The oxidative stress induced by reactive oxygen species (ROS) may play an important role in the pathogenesis of neurodegenerative diseases. In this study, we investigated the neuroprotective effects of methanolic extracts of Prunella Spica (PSE) against $H_2O_2$-induced oxidative stress in PC12 cells. The cells exposed to $H_2O_2$-induced oxidative stress were treated with various concentrations of PSE; this treatment resulted in the induction of a dose-dependent protective effect, which was evidenced by the results of MTT reduction assay, lactate dehydrogenase (LDH) release assay, morphological assay, and colony-formation assay. Interestingly, we also observed reduction of apoptotic bodies in the Hoechst staining and flow cytometric analysis. These data show that apoptosis was significantly suppressed in the PC12 cells that were exposed to $H_2O_2$-induced oxidative stress and treated with PSE. These results suggest that Prunella Spica could be a new potential protective agent against $H_2O_2$-induced oxidative stress.

Effects of Peanut Sprout (Arachis hypogaea L.) Extract on Partial Androgen Deficiency in Aging Males (PADAM) (땅콩나물 추출물이 남성갱년기 증상에 미치는 영향)

  • Sung, Heami;Wee, Ji-Hyang;Jung, Hyun Jung;Kim, Yoon Hee;Moon, Joo Myeng;Jun, Woojin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.11
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    • pp.1571-1579
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    • 2016
  • We investigated the effect of peanut sprout extract (PSE) on andropause symptoms. PSE was evaluated for impotency and benign prostatic hyperplasia via phosphodiesterase (PDE) or 5-alpha reductase II inhibition assay. Inhibition of PDE and 5-alpha reductase II activities in PSE was significantly higher than that of the non-treated control. To investigate the effects of testosterone levels by PSE, we performed cell media test using TM3 cells. Production of testosterone in TM3 cells was elevated by PSE. These results indicate that PSE was able to alleviate andropause symptoms.