• Title/Summary/Keyword: T. B. Lee

Search Result 4,174, Processing Time 0.038 seconds

A NOTE ON QUASI-SIMILAR QUASI-HYPONORMAL OPERATORS

  • Lee, Moo-Sang
    • The Pure and Applied Mathematics
    • /
    • v.2 no.2
    • /
    • pp.91-95
    • /
    • 1995
  • Let H be an arbitrary complex Hilbert space and let (equation omitted)(H) be the *-algebra of all bounded linear operators on H. An operator T in (equation omitted)(H) is called normal if T$\^$*/T = TT$\^$*/, hyponormal if T$\^$*/T $\geq$ TT$\^$*/, and quasi-hyponormal if T$\^$*/(T$\^$*/T - TT$\^$*/)A $\geq$ 0, or equivalently ∥T$\^$*/T$\chi$$\leq$ ∥TT$\chi$∥ for all $\chi$ in H.(omitted)

  • PDF

T-cell epitope specificity for Porphyromonas gingivalis heat shock protein in periodontitis (치주염환자의 Porphyromonas gingivalis 열충격단백에 대한 T-세포 항원 결정부위 특이성 연구)

  • Lee, Ji-Young;Lee, Ju-Yeon;Choi, Jeom-Il
    • Journal of Periodontal and Implant Science
    • /
    • v.33 no.4
    • /
    • pp.543-553
    • /
    • 2003
  • Due to considerably high degree of sequence homology between bacterial and human heat shock proteins(hsp), it has been widely thought that this protein might be involved in autoimmune disease mechanisms in humans. To elucidate how stress proteins contribute in the immunopathogenesis of periodontitis, the present study was performed to evaluate the T cell immune responses specific to Porphyromonas gingivalis (P. gingivalis) heat shock protein (hsp)60 and T-cell epitope specificities for P. gingivalis hsp60 in periodontitis. Anti-P. gingivalis IgG antibody titers were elevated in all patients. We could establish P. gingivalis hsp-specific T cell ines from the peripheral blood of peridontitis, a mixture of $CD4^+$ and $CD8^+$ cells. Of 108 overlapping synthetic peptides spanning whole P. gingivalis hsp60 moleculc, ten peptides with cpitopes specifities for T-cell were showed. Interestingly, ten epitopes were also identified as T-cell epitopes in the present study as well as B-cell epitopes in peridontitis. Therefore, all the ten representative epitopes were designated as common T-and B-cell epitopes for peridontitis. It is critical in developing a peptide vaccine strategy for potential prevention of periodontitis. It was concluded that P. gingivalis hsp60 might be involved in the immunoregulatory process of periodontitis with heat shock protein specificities.

ESSENTIAL SPECTRA OF ${\omega}-HYPONORMAL$ OPERATORS

  • Cha, Hyung-Koo;Kim, Jae-Hee;Lee, Kwang-Il
    • The Pure and Applied Mathematics
    • /
    • v.10 no.4
    • /
    • pp.217-223
    • /
    • 2003
  • Let $\cal{K}$ be the extension Hilbert space of a Hilbert space $\cal{H}$ and let $\Phi$ be the faithful $\ast$-representation of $\cal{B}(\cal{H})$ on $\cal{k}$. In this paper, we show that if T is an irreducible ${\omega}-hyponormal$ operators such that $ker(T)\;{\subset}\;ker(T^{*})$ and $T^{*}T\;-\;TT^{\ast}$ is compact, then $\sigma_{e}(T)\;=\;\sigma_{e}(\Phi(T))$.

  • PDF

Commercial MgB2 superconducting wires at Sam Dong

  • Lee, Dong Gun;Choi, Jun Hyuk;Kim, Du Na;Jeon, Ju Heum;Maeda, Minoru;Choi, Seyong;Kim, Jung Ho
    • Progress in Superconductivity and Cryogenics
    • /
    • v.22 no.2
    • /
    • pp.26-31
    • /
    • 2020
  • Since 2014, Sam Dong Co., Ltd. has successfully developed high-performance MgB2 superconducting wires with a kilometer-scale. Herein, we studied performances of various MgB2 wires fabricated by the Sam Dong with different Cu fractions and diameters for practical applications. Critical current densities of our commercial wire, 18+'1'Cu multifilamentary MgB2 wire, are estimated to be 270,000 A/㎠ at 3 T and 4.2 K and 100,000 A/㎠ at 2 T and 20 K, respectively. We further discuss research progress of various MgB2 superconducting wires at Sam Dong Co., Ltd and make an effort to align with customers' requirements.

Invalid Names Published by T. B. Lee (이창복 교수가 발표한 비합법명)

  • Kim, Hui;Lee, Heung Soo;Park, Sky;Chang, Chin-Sung
    • Korean Journal of Plant Taxonomy
    • /
    • v.35 no.3
    • /
    • pp.211-226
    • /
    • 2005
  • Upon checking 'Illustrated Flora of Korea' which was published in 1980, there were more than ca. 150 apparently invalid names for the Korean plants, which were nomen nudum as well as new combinations or avowed substitutes by T. B. Lee. These names were based on previously and invalidly published names from 'Handbook of Korean Forestry Sciences' and 'An Enumeration of Plants Hitherto Known from Corea'. We consider it useful to summarize the results of this investigation and these invalid names of Korean plants were enlisted here. These invalid names should not be used any more even as synonyms in the literatures.

Effect of Ethanol on Aerobic Biodegradation of Benzene, Toluene, and Ethylbenzene by Rhodococcus sp. EH831 (Rhodococcus sp. EH831에 의한 벤젠, 톨루엔 및 에틸벤젠의 호기성 생분해에 미치는 에탄올의 영향)

  • Lee, Seung-Ha;Lee, Eun-Hee;Cho, Kyung-Suk
    • Microbiology and Biotechnology Letters
    • /
    • v.37 no.3
    • /
    • pp.243-247
    • /
    • 2009
  • The usage of ethanol (EtOH)-blended gasoline (gasohol), has been increasing in recent years. EtOH has influence on the distribution and biodegradation of aromatic compounds such as BTEX (benzene (B), toluene (T), ethylbenzene (B), and xylene (X)) that are gasoline compositions. In this study, the effect of EtOH on the aerobic biodegradation of B, T and E was investigated using a BTEX and EtOH-degrading bacterium, Rhodococcus sp. EH831. The degradation rates of B in the conditions of 1:1, 1:4, and 1:0.25 mixtures with EtOH (B:EtOH, mol:mol) were ranged from $3.82{\pm}0.20$ to $5.00{\pm}0.37{\mu}mol{\cdot}g-dry$ cell wight $(DCW)^{-1}{\cdot}h^{-1}$. The degradation rate of T was the fastest in the 1:0.25 mixture ($6.63{\pm}0.06{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and it was the lowest in the 1:4 mixture ($4.41{\pm}0.04{\mu}mol{\cdot}DCW^{-1}{\cdot}h^{-1}$). The degradation rates of E were increased with increasing the addition amount of EtOH: The degradation rate of E was the highest in the 1:4 mixture ($1.60{\pm}0.03{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and the rates were $1.42{\pm}0.06$, $1.30{\pm}0.01$, and $1.01{\pm}0.30{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$ in the 1:1, 1:0.25, 1.0 mixtures, respectively. In conclusion, the biodegradation of B, T, E by Rhodococcus sp. EH831 was not significantly inhibited by the co-existence of EtOH.

MRI Enhancement using Perovskite Material for B1 Field Control at 7T (7T MRI에서 B1 필드 조정을 위해 페로브스카이트 재료를 이용한 자기공명영상 향상)

  • Kim, Yong-Tae;Kim, Joo-Yeon;Baek, Hyeon-Man
    • Journal of the Korean Society of Radiology
    • /
    • v.15 no.4
    • /
    • pp.565-573
    • /
    • 2021
  • The spatial distribution of electromagnetic fields in the human body can be adjusted by using high dielectric materials. This method has a complementary compared to other methods. However, it can be used as a powerful dielectric shimming tool in certain applications. It can be manufactured in a geometrically free shape and a pad manufactured according to the purpose can be applied without any change of the system. Especially in ultrahigh magnetic field (UHF) MRI, the clinical high dielectric pad used to increase the intensity of the transmit (B1+) and receive (B1-) fields, which has low sensitivity due to the high operating frequency, has great potential. In addition, there are few studies applied to UHF MRI. Therefore, in this study, a high dielectric material pad made of calcium titanate suspension was developed in the laboratory. And the signal increase of clinically useful images was confirmed in various protocols of UHF 7T MRI.

Effects on Immune Cell of Short-term Aerobic Exercise by Exercise Intensity and Expenditures Calorie (운동 강도와 에너지소비량에 따른 단기간의 유산소운동이 면역세포에 미치는 영향)

  • Lee, Jung-Ja;Cho, Jung-Yeon
    • The Journal of the Korea Contents Association
    • /
    • v.8 no.11
    • /
    • pp.386-394
    • /
    • 2008
  • The study of subjects were 8 persons. The study measured VO2max of each person and substituted METs at exercise intensity of both VO2max 50% and VO2max 70% in accordance with energy consumption formula to set exercise time at energy consumption of both 300kcal and 600kcal. And, the study substituted inclination and rate at exercise intensity that was measured at preliminary test. T, B, NK cell varied depending upon aerobic exercise to have no significant difference of exercise intensity at relative ratio of T, B, NK lymphocyte of all of lymphocytes and to have significant difference of Expenditures Calorie (p<.01) and interaction (p<.05) by T cell and Expenditures Calorie (p<.01) by B cell and Expenditures Calorie (p<.001) and interaction (p<.05) by NK cell.

Effects of Schizandra chinensis fructus on the Immunoregulatory Action and Apoptosis of L1210 cells (오미자 면역조절작용 및 L1210 세포의 apoptosis 에 미치는 효과)

  • Kwon, Jin;Lee, Se-Jin;So, June-No;Oh, Chan-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.33 no.3
    • /
    • pp.384-388
    • /
    • 2001
  • The effects of MeOH extracts of Schizandra chinensis fructus (SZX) on the immunoregulatory effect (lymphocyte proliferation, subpopulation, nitric oxide production, phagocytic activity) and apoptosis $(sub-G_1\;peak)$ of L1210 cells were examined. The proliferation of splenocytes and thymocytes were enhanced by the addition of $10\;{\mu}g/mL$ of SZX. SZX were administered p.o. once a day for 7 days in adult male BALB/c mice. SZX resulted in altering subpopulation of splenic B and/or T and thymic T lymphocytes, especially the number of $T_H$ cells were markedly increased by the treatment of SZX in vivo and in vitro. SZX treatment induced the apoptotic cell death in L1210 mouse leukemia cells. In addition, SZX accelerated the production of nitric oxide and phagocytic activity in peritoneal macrophages. These results suggest that SZX have an immunoregulatory property and anti-cancer action.

  • PDF

Downregulation of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in human keratinocytes by melanogenic inhibitors

  • Ahn, Kwang-Seok;Lee, Jinseon;Kim, Yeong-Shik
    • Proceedings of the SCSK Conference
    • /
    • 2003.09a
    • /
    • pp.780-803
    • /
    • 2003
  • Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB ($\textrm{NF}_{-{\kappa}}\textrm{B}$) activators [e.g. tumor necrosis factor-$\alpha$, interleukin-1, lipopolysaccharides, and ultraviolet light] leads to phosphorylation and degradation of the inhibitory protein, $\textrm{I}_{{\kappa}}\textrm{B}$. Liberated $\textrm{NF}_{-{\kappa}}\textrm{B}$ is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte. In order to demonstrate the possible role of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of $\textrm{NF}_{-{\kappa}}\textrm{B}$ induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with $\textrm{pNF}_{-{\kappa}}\textrm{B}$-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the $\textrm{NF}_{-{\kappa}}\textrm{B}$ activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation was measured with the SEAP reporter gene assay using a fluorescence detection method. Of the Mis tested, kojic acid ($IC_{50}$/ = 60 $\mu$M) was found to be the most potent inhibitor of UVB-upregulating $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in transfectant HaCaT cells, which is followed by niacinamide ($IC_{50}$/= 540 $\mu$M). Pretreatment of the transfectant HaCaT cells with the Mis, especially kojic acid and niacinamide, effectively lowered $\textrm{NF}_{-{\kappa}}\textrm{B}$ binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells. These observations suggest that Mis working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

  • PDF