• 제목/요약/키워드: Center for Korean Studies

검색결과 7,839건 처리시간 0.041초

Strain Improvement for Enhanced Production of Streptokinase and Streptodornase in Streptococcus sp.

  • HYUN, HYUNG-HWAN;YOON-BUM LEE;KYUNG-HWA SONG;JI-YOUNG JEON;HYUNE-HWAN LEE
    • Journal of Microbiology and Biotechnology
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    • 제7권2호
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    • pp.101-106
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    • 1997
  • Strain improvement for the enhanced production of streptokinase and streptodornase in Streptococcus sp. ATCC 12449 was performed. Strain UB111, a hyperproductive mutant which was isolated by use of nitrosoguanidine and selection of colonies with large clear zones on DNase test agar plates supplemented with $1{\%}$ glucose and $0.5{\%}$ ammonium chloride, produced about 3 fold more streptokinase and streptodornase than the wild type when tested in shake flask fermentations. The enhanced production of both streptokinase and streptodornase was achieved by cultivating the mutant in a pH-controlled fermentor containing fermentation medium enriched with yeast extract ($2.1{\%}$). Under these conditions, the mutant produced 7300 units/ml of streptokinase and 800 units/ml of streptodornase.

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침과 자율신경계 고찰;인체의 심박변이도 중심으로 (Review on acupuncture and autonomic nervous system;Heart rate variability analysis in humans)

  • 채윤병;박히준;구성태;이혜정
    • Korean Journal of Acupuncture
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    • 제24권4호
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    • pp.25-36
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    • 2007
  • Objectives : Acupuncture restores the flow of vital energy in the body by stimulating the organ-specific meridians and enhances cardiac vagal activity and suppresses sympathetic activity. The purpose of this review is to summarize and evaluate the acupuncture studies on autonomic nervous system (ANS). Methods : We conducted a PubMed search to obtain a fair sample of acupuncture studies related ANS published in English in 2007. Each article was reviewed for study objectives and outcomes, as well as acupuncture points, experimental and control interventions. Results : We reviewed a total of 15 studies published from 1997 to 2007. In normal states, acupuncture enhanced either vagal or sympathetic tone depending on the stimulated acupuncture point sites. On the other hand, most of studies demonstrated that acupuncture restored the autonomic dysfunctions in various kinds of stressful states. Conclusions : We reviewed studies that contributed to an understanding of the autonomic mechanisms of acupuncture with the hope that this review will be of benefit to the future studies. Although the relationship between acupuncture and ANS response is still uncertain, acupuncture would be a noteworthy modality for modulating autonomic dysfunction.

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Current Opinion in Molecular Pathology of Ameloblastoma: A Literature Review

  • Dong‑Joon, Lee;Shujin, Li;Han‑Sung, Jung
    • Journal of Korean Dental Science
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    • 제15권2호
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    • pp.121-131
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    • 2022
  • Ameloblastoma is the most representative epithelial odontogenic tumor in the craniofacial region. Through several studies on Ameloblastoma that have been conducted so far, we have been able to get closer to the reality of Ameloblastoma. However, groundbreaking insight into the pathophysiology of Ameloblastoma has not yet been provided. This review assessed three aspects of five recently published papers on Ameloblastoma: cancer stem cells, calcium signaling, and tumor microenvironment, and compared them with previous studies on tumor physiology, including cancer. In addition, the characteristics of Ameloblastoma revealed by the experimental methods presented in the currently published five papers provide the possibility of Ameloblastoma as a study model in general tumor or cancer studies. Furthermore, the mechanisms of action of the chemicals identified in the studies support their potential as candidates for the second-line treatment of Ameloblastoma.

북한어판 CES-D(Center for Epidemiologic Studies Depression Scale-North Korea ; CES-D-NK)의 신뢰도와 타당도 (Reliability and Validity of the North Korean Version of Center for Epidemiologic Studies Depression Scale (CES-D-NK))

  • 박승진;이소희;전진용;이태엽;한정미;안명희;홍진표
    • 대한불안의학회지
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    • 제11권1호
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    • pp.54-60
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    • 2015
  • Objective : To translate Center for Epidemiologic Studies Depression Scale (CES-D) into North Korean language and to examine its reliability and validity Methods : North Korean defectors (n=207) recruited from the call center for North Korean defectors participated. Psychiatrists and psychiatric residents interviewed the participants and made the psychiatric diagnoses. Subsequently, the participants completed the CES-D, Impact of Event-Scale-Revised-North Korea (IES-R-NK), Alcohol Use Disorders Identification Test-North Korea (AUDIT-NK), and Brief Psychological State Inventory for North Korean Refugees (BPSI-NKR) questionnaires. Of the original participants, 143 subjects participated in test-retest reliability study after one week. Results : Cronbach's alpha coefficient of CES-D-NK was superior in both males (0.91) and females (0.93). The test-retest correlation coefficient was high (males, 0.64 ; femals, 0.79). Good convergent validity was evident by significant correlations with IER-R-NK, BPSI-NKR-Depression and BPSI-NKR-PTSD, respectively. CES-D-NK had no or weak correlations with AUDIT-NK and BPSI-NKR-Alcohol, showing its discriminant validity. Conclusion : CES-D-NK could be a reliable and valid tool for screening and assessing depressive symptoms of North Korean defectors.

Structural Effects of the GXXXG Motif on the Oligomer Formation of Transmembrane Domain of Syndecan-4

  • Song, Jooyoung;Kim, Ji-Sun;Choi, Sung-Sub;Kim, Yongae
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3577-3585
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    • 2013
  • Syndecan-4 (heparan sulfate proteoglycan), biologically important in cell-to-cell interactions and tumor suppression, was studied through mutation of the GXXXG motif of its transmembrane domain (Syd4-TM), a motif which governs dimerization. The expression and purification of the mutant (mSyd4-TM) were optimized here to assess the function of the GXXXG motif in the dimerization of Syd4-TM. mSyd4-TM was obtained in M9 minimal media and its oligomerization was identified by SDS PAGE, Circular Dichroism (CD) spectroscopy, mass spectrometry and NMR spectroscopy. The mutant, unlike Syd4-TM, did not form dimers and was observed as monomers. The GXXXG motif of Syd-4TM was shown to be an important structural determinant of its dimerization.

Variable Temperature High-Resolution 19F MAS Solid-State NMR Characterization of Fluorocarbon Rubbers

  • Park, Tae-Joon;Choi, Sung-Sub;Kim, Ji-Sun;Kim, Yong-Ae
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2345-2350
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    • 2011
  • Variable temperature high-resolution $^{19}F$ magic angle spinning (MAS) solid-state NMR spectroscopy was used to characterize fluorocarbon (FKM) rubbers. The high-resolution spectra of copolymers made from two monomers, vinylidene fluoride and hexafluoropropene, and terpolymers composed of vinylidene fluoride, hexafluoropropene, and tetrafluoroethylene, were obtained using MAS speeds of up to 18 kHz combined with high temperatures of up to 200 $^{\circ}C$ at a magnetic field strength of 9.4 Tesla. From these high resolution solid-state NMR spectra, we were able to assign the spectral peaks and differentiate the copolymer FKM from the terpolymer FKM. We also determined quantitatively the monomer compositions of each FKM rubber.

High-yield Expression and Characterization of Syndecan-4 Extracellular, Transmembrane and Cytoplasmic Domains

  • Choi, Sung-Sub;Kim, Ji-Sun;Song, Jooyoung;Kim, Yongae
    • Bulletin of the Korean Chemical Society
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    • 제34권4호
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    • pp.1120-1126
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    • 2013
  • The syndecan family consists of four transmembrane heparan sulfate proteoglycans present in most cell types and each syndecan shares a common structure containing a heparan sulfate modified extracellular domain, a single transmembrane domain and a C-terminal cytoplasmic domain. To get a better understanding of the mechanism and function of syndecan-4 which is one of the syndecan family, it is crucial to investigate its three-dimensional structure. Unfortunately, it is difficult to prepare the peptide because it is membrane-bound protein that transverses the lipid bilayer of the cell membrane. Here, we optimize the expression, purification, and characterization of transmembrane, cytoplasmic and short extracellular domains of syndecan4 (syndecan-4 eTC). Syndecan-4 eTC was successfully obtained with high purity and yield from the M9 medium. The structural information of syndecan-4 eTC was investigated by MALDI-TOF mass (MS) spectrometry, circular dichroism (CD) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. It was confirmed that syndecan-4 eTC had an ${\alpha}$-helical multimeric structure like transmembrane domain of syndecan-4 (syndecan-4 TM) in membrane environments.

인 농도 및 질소원이 광합성 미세조류인 Scenedesmus dimorphus를 이용한 하수고도처리에 미치는 영향 (Effects of phosphorus concentration and nitrogen sources on photoautotrophic microalgae Scenedesmus dimorphus applied wastewater treatment)

  • 김태형;조용범;박정은;황선진
    • 상하수도학회지
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    • 제27권3호
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    • pp.325-329
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    • 2013
  • A result of estimating the effects of initial phosphorus concentration and nitrogen sources on removal of nitrogen and phosphorus in wastewater treatment using Scenedesmus dimorphus shows that there was no difference in microalgae growth amount and nitrogen removal amount by phosphorus concentration(5 ~ 60 mg/L). On the other hand, as initial phosphorus concentration increased, phosphorus removal amount was increased by luxury uptake of microalgae. Scenedesmus dimorphus preferred to ammonia when ammonia(40 mg/L) and nitrate(40 mg/L) are simultaneously presented and nitrogen removal rate of ammonia was high at approximately 20 mg/L/day.

하수고도처리용 미세조류의 최적회수를 위한 전기응집기술 적용에 있어 전류의 영향 (Effects of electric current on electrocoagulation for optimal harvesting of microalgae for advanced wastewater treatment)

  • 이석민;주성진;최경진;장산;황선진
    • 상하수도학회지
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    • 제28권4호
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    • pp.473-478
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    • 2014
  • Microalgae is known as one alternative energy source of the fossil fuel with the small size of $5{\sim}50{\mu}m$ and negative charge. Currently, the cost of microalgae recovery process take a large part, about 20 - 30% of total operating cost. Thus, the microalgae recovery method with low cost is needed. In this study, the optimum current for Scenedesmus dimorphus recovery process using electrocoagulation techniques was investigated. Under the electrical current, Al metal in anode electrode is oxidized to oxidation state of $Al^{3+}$. In the cathode electrode, the water electrolysis generated $OH^-$ which combine with $Al^{3+}$ to produce $Al(OH)_3$. This hydroxide acts as a coagulant to harvest microalgae. Before applying in 1.5 L capacity electrocoagulation reactor, Scenedesmus dimorphus was cultured in 20 L cylindrical reactor to concentration of 1 OD. The microalgae recovery efficiency of electrocoagulation reactor was evaluated under different current conditions from 0.1 ~ 0.3 A. The results show that, the fastest and highest recovery efficiency were achieved at the current or 0.3 A, which the highest energy efficiency was achieved at 0.15 A.