• Title/Summary/Keyword: $k_h$

Search Result 87,764, Processing Time 0.089 seconds

Human ChlR1 Stimulates Endonuclease Activity of hFen1 Independently of ATPase Activity

  • Kim, Do-Hyung;Kim, Jeong-Hoon;Park, Byoung Chul;Lee, Do Hee;Cho, Sayeon;Park, Sung Goo
    • Bulletin of the Korean Chemical Society
    • /
    • v.35 no.10
    • /
    • pp.3005-3008
    • /
    • 2014
  • Human ChlR1 protein (hChlR1), a member of the cohesion establishment factor family, plays an important role in the segregation of sister chromatids for maintenance of genome integrity. We previously reported that hChlR1 interacts with hFen1 and stimulates its nuclease activity on the flap-structured DNA substrate covered with RPA. To elucidate the relationship between hChlR1 and Okazaki fragment processing, the effect of hChlR1 on in vitro nuclease activities of hFen1 and hDna2 was examined. Independent of ATPase activity, hChlR1 stimulated endonuclease activity of hFen1 but not that of hDna2. Our findings suggest that the acceleration of Okazaki fragment processing near cohesions may aid in reducing the size of the replication machinery, thereby facilitating its entry through the cohesin ring.

Inhibiting the Growth of Escherichia coli O157:H7 in Beef, Pork, and Chicken Meat using a Bacteriophage

  • Seo, Jina;Seo, Dong Joo;Oh, Hyejin;Jeon, Su Been;Oh, Mi-Hwa;Choi, Changsun
    • Food Science of Animal Resources
    • /
    • v.36 no.2
    • /
    • pp.186-193
    • /
    • 2016
  • This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm2 E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples.

Effect of ECR-Ion Milling on Exchange Biasing in NiO/NiFe Bilayers

  • D.G. Hwang;Lee, S. S.;Lee, K. H.;Lee, K. B.;Park, D. H.;Lee, H. S.
    • Journal of Magnetics
    • /
    • v.5 no.1
    • /
    • pp.23-25
    • /
    • 2000
  • We have investigated the effects of Ar and$O_2$-ion milling on the exchange coupling field ($H_{ex}$) and coercive field ($H_c$) at the interfaces between substrates and NiO/NiFe films, to understand the exchange biasing mechanism. The $O_2$-ion milling was successfully performed by means of the electron cyclotron resonance (ECR) process. We found that the local roughness gradient of the NiO surface increased by $O_2$-ion milling. The ratio of $H_{ex}/H_c$ increased from 0.87 to 1.77, whereas $H_c$ decreased by almost a half as a results of the ion milling. The decrease in $H_c$could be interpreted as due to the refinement of magnetic domain size, which arose from the increase of the local roughness gradient of the NiO surface. The decrease in low $H_c$, and increase in $H_{ex}$ in NiO spin valves by ECR-ion milling are in the right direction far use in magnetoresistance (MR) heads.

  • PDF

Seroprevalence of Swine Influenza Viruses H1N1 and H3N2 in Gyeongbuk Province, Korea (경북지역 돼지인플루엔자 바이러스(H1N1, H3N2) 항체조사)

  • Chae, Tae-Chul;Kim, Seong-Guk;Cho, Kwang-Hyun;Eo, Kyung-Yeon;Kwon, Oh-Deog
    • Journal of Veterinary Clinics
    • /
    • v.31 no.4
    • /
    • pp.293-297
    • /
    • 2014
  • Swine influenza is an acute respiratory disease prevalent in pig-growing areas worldwide. In total, 518 gilt and sow serum samples and 14 litters (66 samples) of aborted fetuses from 37 farms (average of 14 serum samples per farm) in Gyeongbuk Province were collected between September 2010 and May 2011. All samples were examined for antibodies to swine influenza virus (SIV) H1N1 and H3N2 using enzyme-linked immunosorbent assay (ELISA). The seropositive rates of gilt and sows were 59.8% (310/518) for SIV H1N1, 78.8% (408/518) for H3N2, and 55.6% (288/518) for both subtypes tested. The rate of aborted fetuses was 13.6% (9/66) for H1N1, 9.1% (6/66) for H3N2, and 9.1% for both subtypes. The seroprevalence for H1N1 in gilts and sows was 46.6% (69/148) and 65.1% (241/370), respectively, and that for H3N2 was 78.4% (116/148) and 78.9% (292/370), respectively.

Metal Complexes of Ambidentate Ligand (VIII). Ni (II) and Pd (II) Complexes of Isonitrosomethylacetoacetate Imines (Ambidentate 리간드의 금속착물 (제 8 보). Isonitrosomethylacetoacetate Imine 리간드의 니켈(II) 및 팔라듐(II) 착물)

  • Bon-Chang Goo;Gang-Yeol Choi;Man-Ho Lee;In-Whan Kim
    • Journal of the Korean Chemical Society
    • /
    • v.37 no.7
    • /
    • pp.662-671
    • /
    • 1993
  • New Ni(II) and Pd(II) complexes of isonitrosomethylacetoacetate imine derivatives, Ni(IMAA-NH)(IMAA-NH'), Ni(IMAA-NH)(IMAA-NR), $Pd(IMAA-NH)_2\;and Pd(IMAA-NR)_2(R=CH_3,\;C_2H_5,\;n-C_3H_7,\;n-C_4H_9,\;or\;CH_2C_6H_5)$, where H-IMAA-NH and H-IMAA-NR represent isonitrosomethylacetoacetate imine and N-alkylisonitrosomethylacetoacetate imine derivative, respectively, have been prepared and the structures of the complexes have been studied by elemental analyses, electronic, infrared, and $^1H-\;and\;^{13}C-NMR$ spectroscopies.

  • PDF

Kinetic Study of pH Effects on Biological Hydrogen Production by a Mixed Culture

  • Jun, Yoon-Sun;Yu, Seung-Ho;Ryu, Keun-Garp;Lee, Tae-Jin
    • Journal of Microbiology and Biotechnology
    • /
    • v.18 no.6
    • /
    • pp.1130-1135
    • /
    • 2008
  • The effect of pH on anaerobic hydrogen production was investigated under various pH conditions ranging from pH 3 to 10. When the modified Gompertz equation was applied to the statistical analysis of the experimental data, the hydrogen production potential and specific hydrogen production rate at pH 5 were 1,182 ml and 112.5 ml/g biomass-h, respectively. In this experiment, the maximum theoretical hydrogen conversion ratio was 22.56%. The Haldane equation model was used to find the optimum pH for hydrogen production and the maximum specific hydrogen production rate. The optimum pH predicted by this model is 5.5 and the maximum specific hydrogen production rate is 119.6 ml/g VSS-h. These data fit well with the experimented data($r^2=0.98$).

The hovering Flight Attitude Control of a Helicopter using Mixed $H_2/H_{\infty}$ Control Techniques ($H_2/H_{\infty}$ 혼합 제어 기법을 이용한 헬리콥터의 정지 비행 자세 제어에 관한 연구)

  • Lee, Myung-Wook;Ko, Kang-Woong;Min, Deuk-Gi;Park, Ki-Heon
    • Proceedings of the KIEE Conference
    • /
    • 2000.07d
    • /
    • pp.2599-2601
    • /
    • 2000
  • A helicopter control problem has been researched with many control theory. Especially, study of the hovering flight attitude control of a helicopter has been brisked since 60s with multivariable control theory. In this paper, the modeling is interpreted through the 6-freedom equation. To getting a entire equation, species of parameters and charts are adapted. The $H_2/H_{\infty}$ controller is acquired by mixing the $H_2$ control theory and the $H_{\infty}$ control theory. The $H_2$ control theory is reasonable one to increase the performance of a plant, and the $H_{\infty}$ control theory secures the robust stability. The simulation shows that the helicopter system is being controlled while maintaining performance and robust stability against perturbation.

  • PDF

Mixed $H_2/H_{\infty}$ Finite Memory Controls for Output Feedback Controls of Discrete-time State-Space Systems

  • Ahn, Choon-Ki;Han, Soo-Hee;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.529-534
    • /
    • 2005
  • In this paper, a new type of output feedback control, called a $H_2/H_{\infty}$ fnite memory control (FMC), is proposed for deterministic state space systems. Constraints such as linearity, unbiasedness property, and finite memory structure with respect to an input and an output are required in advance to design $H_2/H_{\infty}$ FMC in addition to the performance criteria in both $H_2$ and $H_{\infty}$ sense. It is shown that $H_2$, $H_{\infty}$, and mixed $H_2/H_{\infty}$ FMC design problems can be converted into convex programming problems written in terms of linear matrix inequalities (LMIs) with some linear equality constraints. Through simulation study, it is illustrated that the proposed $H_2/H_{\infty}$ FMC is more robust against uncertainties and faster in convergence than the existing $H_2/H_{\infty}$ output feedback control schemes.

  • PDF

Fe-H…H-C Dihydrogen Bondings: Synthesis and Structure of trans-[FeH(NCSe)(dppe)2](dppe=Ph2 PCH2 CH2 PPh2 (Fe-H…H-C 이수소 결합: trans-[FeH(NCSe)(dppe)2](dppe=Ph2 PCH2 CH2 PPh2의 합성 및 구조)

  • Baek, Ji Yeong;Han, Won Seok;Lee, Sun Won
    • Journal of the Korean Chemical Society
    • /
    • v.46 no.5
    • /
    • pp.427-436
    • /
    • 2002
  • Reaction of $trans-[FeHCl(dppe)_2]$ (1) with KSeCN led to the formation of $trans-[FeH(NCSe)(dppe)_2](2).$ Compound 2 $·CH_2Cl_2$ was structurally characterized by X-ray diffraction, in which the hydride ligand appears to be involved in the dihydrogen bonding of the type M-H${\cdot}$${\cdot}$${\cdot}$H-C.

Expression and Purification of the Helicase-like Subdomains, H1 and H23, of Reverse Gyrase from A. fulgidus for Heteronuclear NMR study

  • Kwon, Mun-Young;Seo, Yeo-Jin;Lee, Yeon-Mi;Lee, Ae-Ree;Lee, Joon-Hwa
    • Journal of the Korean Magnetic Resonance Society
    • /
    • v.19 no.2
    • /
    • pp.95-98
    • /
    • 2015
  • Reverse gyrase is a hyperthermophile specific protein which introduces positive supercoils into DNA molecules. Reverse gyrase consists of an N-terminal helicase-like domain and a C-terminal topoisomerase domain. The helicase-like domain shares the three-dimensional structure with two tandem RecA-folds (H1 and H2), in which the subdomain H2 is interrupted by the latch domain (H3). To understand the physical property of the hyperthermophile-specific protein, two subdomains af_H1 and af_H23 have been cloned into E. coli expression vector, pET28a. The $^{15}N$-labeled af_H1 and af_H23 proteins were expressed and purified for heteronuclear NMR study. The af_H1 protein exhibits the well-dispersion of amide signals in its $^1H/^{15}N$-HSQC spectra and thus further NMR study continues to be progressed.