• Title/Summary/Keyword: K-Ras

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Study on the Seed Production of Olive Flounder Paralichthys olivaceus in a Pilot Scale Recirculating Aquaculture System

  • Park, Jeong-Hwan;Jo, Jae-Yoon;Kim, Pyong-Kih
    • Journal of Aquaculture
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    • v.21 no.3
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    • pp.125-132
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    • 2008
  • Seed production of olive flounder Paralichthys olivaceus was performed in a pilot RAS. The growth of juvenile olive flounder and changes in water quality were monitored for the entire production period. The pilot RAS consisted of 8 circular culture tanks($4.0mD{\times}1.0mH$), 2 trickling biofilters($1.7mD{\times}2.0mH$), 2 protein skimmers ($0.8mD{\times}2.5mH$), and 4 sedimentation chambers($0.7mD{\times}1.5mH$). The culture surface area was about $100.5m^2$ and the actual working volume was about $106.9m^3$. As many as 300,000 fertilized olive flounder eggs were initially distributed into 2 culture tanks with the water temperature at $19.0^{\circ}C$. Live feeds such as rotifers and Artemia nauplii were fed until the 32nd day after hatching, and a commercial diet was fed from the 19th day to the end of the experiment. After 70 days, 150,256 juveniles with a body length of $65.8{\pm}3.9mm$ were produced in the RAS, with a daily growth rate for body length of 4.7%/day. At this time, the final culture density was 1,495 individuals $m^{-2}$, and 13.6 L of makeup water, 0.071 kW of electricity and 0.025 L of diesel fuel were used to produce a juvenile olive flounder. During metamorphosis of the larvae, the TAN concentration increased to 0.99 mg/L, which made the larvae sensitive to result in some mortality. However no more massive mortality occurred at the juvenile stage after metamorphosis even at a TAN concentration of 4.25 mg/L and a ${NO_2}^{-}-N$ concentration of 2.45 mg/L.

Research on CR/Nylon 6 Cord Rubber Sleeve of Rubber Air Spring (고무 공기 스프링용 CR/Nylon 6 코드 고무 슬리브에 대한 연구)

  • Seo, Jae-Chan;Kim, Dae-Jin;Park, Hae-Youn;Seo, Kwan-Ho
    • Elastomers and Composites
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    • v.49 no.4
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    • pp.293-304
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    • 2014
  • Rubber air spring (RAS) is a special suspension device for the industries of automobile, railroad car and other transportation. A RAS serves as a spring component with the elastic effect of compression and expansion of air in a composite rubber bag. The main component of RAS is the rubber sleeve. Rubber sleeve is the composite which is made up of combination of chloroprene rubber (CR) and nylon 6 cord, and the adhesive strength between CR and nylon 6 cord is very important. In this study, considering the effects of additives in rubber sleeve, various physical properties were tested to find the optimal combination of composition and conditions. Further, in order to select the optimum orientation of the reinforcing fibers, numerical analysis was performed using the finite elements method. After assembling all components of RAS, it was mounted on an actual vehicle, and then it was tested air leakage, fatigue life and fundamental properties.

GST2 is Required for Nitrogen Starvation-Induced Filamentous Growth in Candida albicans

  • Lee, So-Hyoung;Chung, Soon-Chun;Shin, Jongheon;Oh, Ki-Bong
    • Journal of Microbiology and Biotechnology
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    • v.24 no.9
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    • pp.1207-1215
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    • 2014
  • Candida albicans, the major human fungal pathogen, undergoes morphological transition from the budding yeast form to filamentous growth in response to nitrogen starvation. In this study, we identified a new function of GST2, whose expression was required for filamentous growth of C. albicans under nitrogen-limiting conditions. The Gst2p showed Gst activity and required response to oxidative stress. The ${\Delta}gst2$ mutant displayed predominantly yeast phase growth in low ammonium media. Such morphological defect of ${\Delta}gst2$ mutants was not rescued by overexpression of Mep2p, Cph1p, or Efg1p, but was rescued by either overexpression of a hyperactive $RAS1^{G13V}$ allele or through exogenous addition of cyclic AMP. In addition, the ${\Delta}gst2$ mutants had lower levels of RAS1 transcripts than wild-type cells under conditions of nitrogen starvation. These results were consistent with the Ras1-cAMP pathway as a possible downstream target of Gst2p. These findings suggest that Gst2p is a significant component of nitrogen starvation-induced filamentation in C. albicans.

DNAJB9 Inhibits p53-Dependent Oncogene-Induced Senescence and Induces Cell Transformation

  • Lee, Hyeon Ju;Jung, Yu-Jin;Lee, Seungkoo;Kim, Jong-Il;Han, Jeong A.
    • Molecules and Cells
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    • v.43 no.4
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    • pp.397-407
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    • 2020
  • DNAJB9 is known to be a member of the molecular chaperone gene family, whose cellular function has not yet been fully characterized. Here, we investigated the cellular function of DNAJB9 under strong mitogenic signals. We found that DNAJB9 inhibits p53-dependent oncogene-induced senescence (OIS) and induces neoplastic transformation under oncogenic RAS activation in mouse primary fibroblasts. In addition, we observed that DNAJB9 interacts physically with p53 under oncogenic RAS activation and that the p53-interacting region of DNAJB9 is critical for the inhibition of p53-dependent OIS and induction of neoplastic transformation by DNAJB9. These results suggest that DNAJB9 induces cell transformation under strong mitogenic signals, which is attributable to the inhibition of p53-dependent OIS by physical interactions with p53. This study might contribute to our understanding of the cellular function of DNAJB9 and the molecular basis of cell transformation.

Influence of Filler Shape on Dielectric & Electric Charge-Discharge Properties of Filled Epoxy Resin (에폭시 수지의 유전특성.충방전특성에 미치는 충전제 형상의 영향)

  • 이성일;박일규;류성림;주인규
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.11a
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    • pp.81-84
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    • 2000
  • In this paper, we have the investigated the Influence of Filler Shape on Dielectric & Electric Charge-Discharge Properties of Filled Epoxy Resin. In the low frequency range from 50Hz to a few kHz, the maginitude of tan$\delta$ become larger in the order, NON, RAS, SAS, SCS. The electrical Discharge of RAS measured for 60 min, decreased after 10$^2$∼10$^3$.

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Influence of Filler Shape on Dielectric & Electric Charge-Discharge Properties of Filled Epoxy Resin (에폭시 수지의 유전특성.충방전특성에 미치는 충전제 형상의 영향)

  • 이성일;박일규;류성림;주인규
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.81-84
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    • 2000
  • In this paper, we have the investigated the Influence of Filler Shape on Dielectric & Electric Charge-Discharge Properties of Filled Epoxy Resin. In the low frequency range from 50Hz to a few kHz, the magnitude of tan$\delta$ become larger in the order, NON, RAS, SAS, SCS. The electrical Discharge of RAS measured for 60 min, decreased after 10$^2$∼10$^3$.

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Implementation and Application of Integrated Model for ALT(Accelerated Life Test) (ALT 통합모형의 적용 및 응용)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2008.11a
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    • pp.153-160
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    • 2008
  • This paper presents the log likelihood function for integrated models for ALT such as exponential-general Eyring, Weibull-temperature and specific heat, lognormal-temperature and specific heat. Additionally this paper estimates the system reliability and mean time to failure(MTTF) for series, parallel, k of n, and standby system using ALT linkage parameter. Lastly this study designs three variable reliability acceptance sampling(RAS) plans such as type I, II censored test, sequential test by the use of integrated models for ALT.

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Differential Activation of Ras/Raf/MAPK Pathway between Heart and Cerebral Artery in Isoproterenol-induced Cardiac Hypertrophy

  • Kim, Hyun-Ju;Kim, Na-Ri;Joo, Hyun;Youm, Jae-Boum;Park, Won-Sun;Warda, Mohamed;Kang, Sung-Hyun;Thu, Vu-Thi;Khoa, Tran-Minh;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.5
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    • pp.299-304
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    • 2005
  • Cardiac hypertrophy contributes an increased risk to major cerebrovascular events. However, the molecular mechanisms underlying cerebrovascular dysfunction during cardiac hypertrophy have not yet been characterized. In the present study, we examined the molecular mechanism of isoproterenol (ISO)-evoked activation of Ras/Raf/MAPK pathways as well as PKA activity in cerebral artery of rabbits, and we also studied whether the activations of these signaling pathways were altered in cerebral artery, during ISO-induced cardiac hypertrophy compared to heart itself. The results show that the mRNA level of c-fos (not c-jun and c-myc) in heart and these genes in cerebral artery were considerably increased during cardiac hypertrophy. These results that the PKA activity and activations of Ras/Raf/ERK cascade as well as c-fos expression in rabbit heart during cardiac hypertrophy were consistent with previous reports. Interestingly, however, we also showed a novel finding that the decreased PKA activity might have differential effects on Ras and Raf expression in cerebral artery during cardiac hypertrophy. In conclusion, there are differences in molecular mechanisms between heart and cerebral artery during cardiac hypertrophy when stimulated with β2 adrenoreceptor (AR), suggesting a possible mechanism underlying cerebrovascular dysfunction during cardiac hypertrophy.

High Frequency of TP53 but not K-ras Gene Mutations in Bolivian Patients with Gallbladder Cancer

  • Asai, Takao;Loza, Ernesto;Roig, Guido Villa-Gomez;Ajioka, Yoichi;Tsuchiya, Yasuo;Yamamoto, Masaharu;Nakamura, Kazutoshi
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.13
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    • pp.5449-5454
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    • 2014
  • Although genetic characteristics are considered to be a factor influencing the geographic variation in the prevalence of gallbladder cancer (GBC), they have not been well studied in Bolivia, which has a high prevalence rate of GBC. The purpose of this study was to examine the frequency of TP53 and K-ras mutations in Bolivian patients with GBC and to compare them with our previous data obtained in other high-GBC-prevalence countries, namely Japan, Chile, and Hungary. DNA was extracted from cancer sites in paraffin-embedded tissue from 36 patients using a microdissection technique. TP53 mutations at exons 5 to 8 and K-ras mutations at codons 12, 13 and 61 were examined using direct sequencing techniques. The data obtained were compared with those in the other high-GBC-prevalence countries. Of the 36 patients, 18 (50.0%) had a TP53 mutation (one mutation in each of 17 patients and three mutations in one patient), and only one (2.8%) had a K-ras mutation. Of the 20 TP53 mutations, 12 were of the transition type (60.0%). This rate was significantly lower than that in Chile (12/12, P<0.05). In addition, three mutations were of the CpG transition type (15.0%), which is a feature of endogenous mutation. All three were found in the hot spot region of the TP53 gene. In contrast, G:C to T:A transversion was found in Bolivia, suggesting the presence of exogenous carcinogens. Our findings suggest that the development of GBC in Bolivia is associated with both exogenous carcinogens and endogenous mechanisms. The identification of an environmental risk factor for GBC is needed to confirm these findings.

Effects of Rhythmic Auditory Stimulation Using Music on Gait With Stroke Patients

  • Oh, Yong-seop;Kim, Hee-soo;Woo, Young-keun
    • Physical Therapy Korea
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    • v.22 no.3
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    • pp.81-90
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    • 2015
  • This study aimed to determine the effects of Rhythmic Auditory Stimulation (RAS) using music and a metronome on the gait of stroke patients. 13 female and 15 male volunteers were randomly allocated to two groups: namely a group to receive RAS using music and a metronome group (the experimental group; $n_1=14$) and a group to receive RAS using a metronome only (the control group; $n_2=14$). The affected side was the left side in 15 subjects and the right side in 13 subjects. The mean age of the subjects was 56.6 years, and the mean onset duration of stroke was 8.6 months. Intervention was applied for 30 minutes per session, once a day, 5 times a week for 4 weeks. To measure the patients' gait improvement, we measured gait velocity, cadence, stride length, double limb support using GAITRite, body center sway angle using an accelerometer, and Timed Up-and-Go test. Functional Gait Assessment were conducted before and after the experiment. The paired t-test was used for comparisons before and after the interventions in each group. Analysis of covariance was used for comparisons between the groups after the interventions. Statistical significance was set at ${\alpha}=.05$. Within each of the two groups, significant differences in all of the dependent variables before and after the experiment (p<.05) were observed. However, in the comparison between the two groups, the experimental group showed more significant improvements in all dependent variables than the control group (p<.05). Our results also suggest that in applying RAS in stroke patients, the combination of music and a metronome is more effective than using a metronome alone in improving patients' gait.