• Title/Summary/Keyword: d-nucleus

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Microbial Degradation of Plant Sterol to Steroidol Intermediates by a Mutant of Mycobacterium sp (Mycobacterium sp. 변이주에 의한 식물스테롤의 스테로이드 중간체로의 미생물적 분해)

  • 이강업;제임스쥬
    • Microbiology and Biotechnology Letters
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    • v.18 no.1
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    • pp.12-17
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    • 1990
  • A mutant of Mycobacterium sp. has been isolated which is capable of degrading cholesterol and plant sterol to androst-4-ene-3, 17-dione and 9-hydroxyandrostene-3, 17-dione. Also this mutant hydroxylated the steroidal nucleus at the 9 $\alpha$ position. No ring degradation inhibitory agents are required for these processes.

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Thermodynamic properties and structural geometry of KMgCl3·6H2O single crystals

  • Yoon, Hyo In;Lim, Ae Ran
    • Journal of the Korean Magnetic Resonance Society
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    • v.19 no.3
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    • pp.119-123
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    • 2015
  • The thermodynamic properties and structural geometry of $KMgCl_3{\cdot}6H_2O$ were investigated using thermogravimetric analysis, differential scanning calorimetry, and nuclear magnetic resonance. The initial mass loss occurs around 351 K ($=T_d$), which is interpreted as the onset of partial thermal decomposition. Phase transition temperatures were found at 435 K ($=T_{C1}$) and 481 K ($=T_{C2}$). The temperature dependences of the spin-lattice relaxation time $T_1$ for the $^1H$ nucleus changes abruptly near $T_{C1}$. These changes are associated with changes in the geometry of the arrangement of octahedral water molecules.

Nanocomposite Magnetic Powder Materials using Mechano-chemical Synthesis

  • Mofa, N.N.;Ketegenov, T.A.;Mansurov, Z.A.;Soh, D.W.
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.1
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    • pp.29-33
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    • 2004
  • The materials showing high structure dispersity have been developed on the quartz base by mechano-chemical technology. Depending on the processing conditions and subsequent applications, the materials produced by mechano-chemical reaction (MCR) showed concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segneto-magnetics, contained a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds was synthesized having thickness up to 10∼50 nm and showing magnetic properties and etc.

Solid-State High-Resolution 1H-NMR Study for Ammonia Borane of Hydrogen Storage Material

  • Han, J.H.;Lee, Cheol-Eui;Kim, Se-Hun;Kim, Chang-Sam;Han, Doug-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.14 no.1
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    • pp.38-44
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    • 2010
  • In liquids NMR, $^{1}H$ is the most widely observed nucleus, which is not the case in solids NMR. The reason is due to the strong homo-dipolar interactions between the hydrogen atoms which mask the useful chemical shift information. Therefore we must remove the strong homo-dipolar interactions in order to get structural information, which can be investigated by the isotropic chemical shift. There are two ways of obtaining it. One is the ultra-fast MAS of ca. 70 kHz spinning speed, which has become available only recently. The other way is devising a pulse sequence which can remove the strong homo-dipolar interaction. In the latter way, MAS with a moderate spinning rate of a few kHz, is enough to remove the chemical shift anisotropy. In this report, 1D-CRAMPS and 2D MASFSLG techniques are utilized and their results will be compared. This kind of highresolution $^{1}H$ NMR for solids, should become a valuable analytical tool in the understanding and the developing of a new class of hydrogen storage materials. Here ammonium borane $-NH_{3}BH_{3}$, whose hydrogen content is high, is used as a sample.

Nucleolar translocalization of GRA10 of Toxoplasma gondii transfectionally expressed in HeLa cells

  • Ahn, Hye-Jin;Kim, Sehra;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • v.45 no.3
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    • pp.165-174
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    • 2007
  • Toxoplasma gondii GRA10 expressed as a GFP-GRA10 fusion protein in HeLa cells moved to the nucleoli within the nucleus rapidly and entirely. GRA10 was concentrated specifically in the dense fibrillar component of the nucleolus morphologically by the overlap of GFP-GRA10 transfection image with IFA images by monoclonal antibodies against GRA10 (Tg378), B23 (nucleophosmin) and C23 (nucleolin). The nucleolar translocalization of GRA10 was caused by a putative nucleolar localizing sequence (NoLS) of GRA10. Interaction of GRA10 with TATA-binding protein associated factor 1B (TAF1B) in the yeast two-hybrid technique was confirmed by GST pull-down assay and immunoprecipitation assay. GRA10 and TAF1B were also co-localized in the nucleolus after co-transfection. The nucleolar condensation of GRA10 was affected by actinomycin D. Expressed GFP-GRA10 was evenly distributed over the nucleoplasm and the nucleolar locations remained as hollows in the nucleoplasm under a low dose of actinomycin D. Nucleolar localizing and interacting of GRA10 with TAF1B suggested the participation of GRA10 in rRNA synthesis of host cells to favor the parasitism of T. gondii.

Sesquiterpene Pyridine Alkaloids from Euonymus japonica (사철나무의 알칼로이드 성분)

  • Ryu, Jae-Ha;Eun, Jin-Hee;Lee, So-Young;Chang, Joon-Shik;Park, Man-Ki;Park, Jeong-Hill;Han, Yong-Nam;Han, Byung-Hoon
    • YAKHAK HOEJI
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    • v.41 no.5
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    • pp.554-558
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    • 1997
  • Two alkaloidal components were isolated from the ether soluble part of the MeOH extract of the root bark of Euonymus japonica. Their structures were elucidated by the spe ctroscopic analylses as the sesquiterpene pyridine alkaloids derived from polyester sesquiterpenes which are characteristically detected in Celastraceae plants. These include macrocycle formed by two ester linkages between dihydro-${\beta}$-agarofuran nucleus and pyridinic dibasic acid(compound 1:evoninic acid, compound 2:wilfordic acid). The structure of compound $1[C_{47}H_{50}N_2O_{17},\;mp\;161{\sim}163^{circ}C$. $[{\alpha}]_D^{28}=+31.6^{\circ}$(c, 0.1 in EtOH)] was determined as novel structure named as euojaponine N, and compound $2[C_{48}H_{57}NO_{18},\;mp\;142{\sim}145^{circ}C,\;[{\alpha}_D^{27}=+27.0^{\circ}$(c, 0.1 in EtOH)] was identified as ebenifoline W-I reported from Maytenus ebenifolia.

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Signal Processing and Implementation of Transmitter for Cochlear Implant (인공 와우를 위한 신호 처리 및 전달부의 구현)

  • Chae, D.;Choi, D.;Byun, J.;Baeck, S.;Kong, H.;Park, S.
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.284-286
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    • 1993
  • Software and hardware for cochlear implant system have been developed to create a speech signal processing system which, in real-time, extracts model parameter including formants, pitch, amplitude information. The system is based on the Texas Instruments TMS320 family. In hardware, computer interface has been desisted and implemented that allows presentation of biphasic pulse stimuli to patients with the hearing handicapped. The host computer sends a stream of bytes to the parallel port. Upon receipt of the data the interface generates the appropriate burst sequence that is delivered to the patient's external transmitter coil. The coded information is interpreted by the Nucleus-22 internal receiver that delivers the pulse to the specified electrodes at the specified amplitude and pulse width.

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The Effects of 120Hz Electroacupuncture on the Prostaglandin E2 and Spinal N-Methyl-D-Aspartate Receptor Expression in the Carrageenan-Injected Rat (고빈도 120 Hz 전침이 Carrageenan으로 유발된 흰쥐의 Prostaglandin E2와 척수 N-Methyl-D-Aspartate Receptor 발현에 미치는 영향)

  • Son, In-seok;Choi, Byung-tae;Jang, Kyung-jeon
    • Journal of Acupuncture Research
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    • v.20 no.3
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    • pp.15-23
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    • 2003
  • Objective : The role of high frequency 120 Hz electroacupuncture(EA) in carrageenan-induced pain was studied by examining the alnalgesic effects, and prostaglandin $E_2(PGE_2)$ levels measurement and spinal N-methyl-D-aspartate(NMDA) receptor expression. Inflammation was induced by an intraplantar injection of 1% carrageenan into the right hind paw. Method : Bilateral EA stimulation with 120 Hz were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles for a total of 30 min duration in carrageenan-injected rats. Results : EA stimulation showed significant analgesic effects as measured by analgesy-meter at all time points tested compared with controls. Three hours after carrageenan injection, PGE2 levels were measured by commercial kit. EA significantly inhibited PGE2 production in the right paw. The number of NR1 and NR2A, NMDA receptor, immunoreactive neurons was significantly increased in the superficial dorsal horn(laminae I-II) and nucleus proprius(laminae III-IV) of ipsilateral spinal cord at L4-5. But the number of carrageenan-induced NR1 and NR2A immunoreactive neuron, especially NR1 immunoreaction in the superficial dorsal horn, was reduced by 120 Hz EA stimulation. Conclusions : These results indicate that NMDA receptors may mediate transmission of nociceptive information originating in tissue inflammation of hind paw and high frequency 120 Hz EA stimulation have an alleviating action against local inflammatory pain.

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Changes in Plasma Steroid Hormone Levels and Gonad Development by the Control of Photoperiods and Water Temperatures on Timing of Sexual Maturity of Rockfish (Sebastes schlegeli)

  • Baek Hea-Ja;Park Moo-Eog;Lee Young-Don;Kim Hyung-Bae;Rho Sum
    • Fisheries and Aquatic Sciences
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    • v.7 no.1
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    • pp.16-22
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    • 2004
  • Plasma steroid hormone levels in the viviparous rockfish (Sebastes schlegeli) were examined in relation to gonadal histology under controlled photoperiods and water temperatures. To investigate those effects in S. schlegeli the photoperiod was maintained at 15L:9D in June and then it was gradually decreased to 9L: 15D in October. It was then gradually increased to 12L:12D in January, followed by 14L:I0D in February. The water temperature was $19-20^{\circ}C$ in July. From August to October, it was from $18^{\circ}C\;to\;12^{\circ}C$. Then, it was dropped to a low of $19-11^{\circ}C$ in November to December and then gradually increased to $14-15^{\circ}C$ in February. In females, both plasma $estradiol-l7\beta\;$ (E2) and testosterone (T) levels from August to February showed a similar pattern in both the treatment and the control groups. In the treatment group, the peaks of plasma E2 and T were observed in November, and the peaks were closely correlated to histological observations. Oocytes contained many yolk globules (final vitellogenic oocytes), and oocytes at the migratory nucleus stage increased in size. Plasma levels of progesterone did not change much throughout the experimental period. However, in the control group, the peaks of E2, T, and progesterone were observed in February. These results indicate that the controlled photoperiod and water temperature accelerated sexual maturity, corresponding to the advancement of plasma E2 and T peaks by approximately 3 months. In males, plasma T levels showed a similar pattern from August to October in the treatment and control groups, though levels in the treatment group were higher than those in the control group. From histological observations, the treatment group copulated one month earlier.

The Study of in Vivo Visual Pathway Tracing using Magnetic Magnanese Tracer (자성 망간 추적자를 이용한 in Vivo 시신경경로 추적에 관한 연구)

  • Bae, Sung-Jin;Chang, Yong-Min
    • Progress in Medical Physics
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    • v.18 no.1
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    • pp.42-47
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    • 2007
  • Purpose: To evaluate the tracing of optic nerve tract using manganese enhanced magnetic resonance Imaging. Materials and Methods: After injecting $30{\mu}l$ of $MnCl_2(1mol)$ (1 mol) Into the retina of female New Zealand white rabbit, the contrast enhancements at major anatomical structures of optic nerve tract were evaluated by high resolution T1-weighted Images 12 hours, 24 hours, and 48 hours after $MnCl_2(1mol)$ Injection using 3D FSPGR (Fast Speiled Gradient Recalled echo) pulse sequence at 1.5T clinical MR scanner with high performance gradient system. Also, for quantitative evaluation, the signal-to-noise ratios of circular ROI on anatomical locations were measured. Results: The major structures on the optic nerve tract were enhanced after injecting $MnCl_2(1mol)$. The structures, which showed enhancement, were right optic nerve, optic chiasm, left optic tract, left lateral geniculate nucleus, left superior colliculus. The structures on the contralateral optic pathway to the right retina were enhanced whereas the structures on the ipsilateral pathway did not show enhancement. Conclusion: The Mn transport through axonal pathway of optic nerve sys)em was non- invasively observed after injecting injecting $MnCl_2$ at the retina, which is the end terminal of optic nerve system. This Mn transport seems to occur by voltage gated calcium $(Ca^{2+})$ channel and In case of direct Injection Into the retina, the fast transpori pathway of voltage gated calcium channel seems to be responsible for Mn transport.

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