• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.442-446
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• 1998

$\alpha$--sulfur single crystal which has orthorohmbic structure was grown using Bridgman method. The indirect optical energy band gap of this crystal are 2.65 and 2.82 eV at 10 and 300K, respectively. The wavelengths of photoluminecence(PL) peaks are 543 and 596 nm at 10k, By thermally stimulated current (TSC) method, two electron traps($D_1,D_2$) located at 0/23 and 0.43eV below the conduction band and a hole trap(A) located at 0.31 eV above the valence band are observed. PL mechanism of $\alpha$-sulfur single crystal is analyzed using the values of optical energy band gap at 10k two electron traps and a hole trap.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.4
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• pp.39-61
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• 2008

Objectives : The present study was performed to investigate whether acupuncture stimulation in the rats affected regeneration properties of the injured sciatic nerve. A differential effect of acupuncture stimulation on the one point near the spinal nerve root controlling sciatic nerve activity and the other point in the peripheral area subordinated by injured nerve was compared. Materials and Methods: Rat sciatic nerves were injured by crush, and the effects on axonal regeneration on injured sciatic nerves were evaluated by acupuncture stimulation at two different regions. In proximal acupuncture stimulation group, acupuncture stimulation was performed on Huatuo Jiaji(EX B2) points located from L5 to S1 vertebral levels to stimulate the nearest spinal nerve root that innervates sciatic nerves. In distal acupuncture stimulation group, acupuncture stimulation was performed on Zusanli(ST 36) and Weizhong(BL 40) points to stimulate at peripheral area dominated by injured sciatic nerves. Acupuncture stimulation was given every other days for 1 or 2 weeks. Sciatic nerve tissues collected from acupuncture stimulation experimental groups, injury control group, and intact animal group were used for protein analysis by Western blotting or Hoechst nuclear staining. To determine axonal regeneration, Dil fluorescence dye was injected into the sciatic nerve 0.5 cm distal to the injury site in individual animal groups and Dil-labeled cells by retrograde tracing were measured in the DRG at lumbar 5 or in the spinal cord. DRG sensory neurons prepared from individual animal groups were used to measure the extent of neurite outgrowth and for immunofluorescence staining with anti-GAP-43 antibody. Results : Animal groups given proximal or distal acupuncture stimulation showed upregulation of GAP-43 and Cdc2 protein levels in the sciatic nerve at 7 days after injury. Cdk2 protein levels were strongly induced by nerve injury, but did not show changes by acupuncture stimulation. Phospho-Erk1/2 protein levels were elevated by acupuncture stimulation above those present in the injury control animals. These increase in regeneration-associated protein levels appeared to be related with increase cell proliferation in the injured sciatic nerves. Hoechst 33258 staining of sciatic nerve tissue to visualize nuclei of individual cells showed increased Schwann cell number in the distal portion of the injured nerve 7 and 14 days after injury and further increases by acupuncture stimulation particularly at the proximal position. Measurement of axonal regeneration by retrograde tracing showed significantly increased Dil-labeled cells in proximal acupuncture stimulation group compared to distal acupuncture stimulation group and injury control group. Finally, an evaluation of axonal regeneration by retrograde tracing showed increased number of Dil labeled cells in the DRG at lumbar 5 or in the ventral horn of the spinal cord at lower thoracic level at 7 days after nerve injury. Conclusions : The present data show that the proximal acupuncture stimulation at Huatuo Jiaji(EX B2) points governing injured sciatic nerves was more effective for axonal regeneration than the distal acupuncture stimulation. Further studies on functional recovery or associated molecular mechanisms should be critical for developing animal models and clinical applications.

• Journal of Labour Economics
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• v.43 no.2
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• pp.75-107
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• 2020

Using the data from 1980 to 2017, I show the long-term trends in the gender wage gap in Korea and analyze factors using decomposition method. It tended to decline until the 1990s, but gradually slowed after the 2000s. Gelbach(2016)'s decomposition method is used as an alternative rather than Blinder-Oaxaca decomposition. The results show that the proportion of explanation of traditional factors, such as age, education, firm size, industry and occupation, are continuously decreasing in explaining the gender wage gap. Expecially, the proportion of explanation of age and that of education have decreased, and that of industry tended to decrease in the 1990s but to increase after the 2000s.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2333-2337
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• 2007

Nanoporous TiO2 and ZrO2 thin films were spin-coated using a surfactant-templated approach from Pluronic P123 (EO20PO70EO20) as the templating agent, titanium alkoxide (Ti(OC4H9)4) as the inorganic precursor, and butanol as a the solvent. The control of the electronic structure of TiO2 is crucial for its various applications. We found that the band gap of the hybrid nanoporous thin films can be easily tuned by adding an acetylacetonestabilized Zr(OC4H9)4 precursor to the precursor solution of Ti(OC4H9)4. Pores with a diameter of 5 nm-10 nm were randomly dispersed and partially connected to each other inside the films. TiO2 and ZrO2 thin films have an anatase structure and tetragonal structure, respectively, while the TiO2-ZrO2 hybrid film exhibited no crystallinity. The refractive index was significantly changed by varying the atomic ratio of titanium to zirconium. The band gap for the nanoporous TiO2 was estimated to 3.43 eV and that for the TiO2-ZrO2 hybrid film was 3.61 eV.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8271-8279
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• 2016

Background: Hepato-carcinogenesis is multifaceted in its molecular aspects. Among the interplaying agents are altered gap junctions, the proteasome/autophagy system, and mitochondria. The present experimental study was designed to outline the roles of these players and to investigate the tumor suppressive effects of curcumin with or without mesenchymal stem cells (MSCs) in hepatocellular carcinoma (HCC). Materials and Methods: Adult female albino rats were divided into normal controls and animals with HCC induced by diethyl-nitrosamine (DENA) and $CCl_4$. Additional groups treated after HCC induction were: Cur/HCC which received curcumin; MSCs/HCC which received MSCs; and Cur+MSCs/HCC which received both curcumin and MSCs. For all groups there were histopathological examination and assessment of gene expression of connexin43 (Cx43), ubiquitin ligase-E3 (UCP-3), the autophagy marker LC3 and coenzyme-Q10 (Mito.Q10) mRNA by real time, reverse transcription-polymerase chain reaction, along with measurement of LC3II/LC3I ratio for estimation of autophagosome formation in the rat liver tissue. In addition, the serum levels of ALT, AST and alpha fetoprotein (AFP), together with the proinflammatory cytokines $TNF{\alpha}$ and IL-6, were determined in all groups. Results: Histopathological examination of liver tissue from animals which received DENA-$CCl_4$ only revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules. Administration of curcumin, MSCs; each alone or combined into rats after induction of HCC improved the histopathological picture. This was accompanied by significant reduction in ${\alpha}$-fetoprotein together with proinflammatory cytokines and significant decrease of various liver enzymes, in addition to upregulation of Cx43, UCP-3, LC3 and Mito.Q10 mRNA. Conclusions: Improvement of Cx43 expression, nonapoptotic cell death and mitochondrial function can repress tumor growth in HCC. Administration of curcumin and/or MSCs have tumor suppressive effects as they can target these mechanisms. However, further research is still needed to verify their effectiveness.

• Development and Reproduction
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• v.5 no.2
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• pp.115-122
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• 2001

Production of a mature oocyte is a complex process that requires the close association between oocyte and follicular cells. The present study was conducted to investigate the difference between oocytes with and without close junctional communication with cumulus cells and the involvement of two connexins(CXs) in the interactions. Follicles at different sizes(small: 200～400 ㎛; large:>450 ㎛) were mechanically isolated from PMSG-primed mouse ovaries, and punctured to get cumulus-oocyte complex(COC). Oocytes were released themselves(denuded), with partially attached(partial), or with tightly attached(intact) cumulus cells. Maturation and fertilization capacity of the COCs were measured. Expression of CX 37 and CX 43 was examined by RT-PCR and in situ hybridization. The ratio between intact COC and denude/partial oocytes was 30％(SI) and 70％(SPD) in small follicles, while 55％(LI) and 45％(LPD) in large follicles, respectively. Maturation and fertilization rates of the released oocytes were similar among SI, LPD, LI groups, but those were significantly lower in SPD oocytes. In oocytes, CX 37 was the major CX and CX 43 was not expressed, whereas in the cumulus cells, CX 43 was the major, and CX 37 was the next. Results of the present study suggest that 1) immature oocytes from small follicles with intact cell-to-cell communication with cumulus have the similar quality to that of the oocytes from larger follicles, 2) gap junction between oocyte and cumulus cells may be the heterotypic channel, and 3) we could not explain the difference in the cell-to-cell communication between intact and partial/denuded COCs through the expression of the two CXs.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.42-43
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• 2011

• 월간산업보건
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• s.367
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• pp.40-43
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• 2018

대한산업보건협회는 유방 건강에 대한 정보와 유방암에 대한 인식을 높이기 위해 마련된 핑크런 마라톤대회에 올해부터 동참하고 있다. 임직원들은 노사가 함께하는 사회공헌활동으로 기부문화의 정착을 위해 자발적으로 참여하고 있으며, 암진단을 받은 직원들이 치료에만 전념할 수 있도록 복지에도 앞장서 큰 의미를 더하고 있다.

• Journal of Korean Biological Nursing Science
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• v.22 no.4
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• pp.223-231
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• 2020

Purpose: The purpose of this study was to investigate the effects of taro extract on brain resilience in in vitro Parkinson's disease model induced by 6-hydroxydopamine (6-OHDA). Methods: To induce a neuroinflammatory reaction and the in vitro Parkinson's disease model, SH-SY5Y cells were stimulated with lipopolysaccharide (LPS) and 6-OHDA, respectively. After that, cells were treated with at various concentrations (1, 5, and 10 mg/mL) of taro extract. Then nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), interleukin (IL)-6, synaptophysin (SYP) and growth associated protein (GAP)-43 messenger ribonucleic acid (mRNA) expression level were measured. Results: Taro extract significantly suppressed LPS-induced NO production. Meanwhile, iNOS and IL-6 mRNA expression decreased in a dose-dependent manner. In addition, taro increased the mRNA expression of SYP and GAP-43 mRNA. Conclusion: These findings indicate that taro played an important role in brain resilience by inhibiting neuronal cell death and promoting neurite outgrowth, synaptogenesis, and neural plasticity. The results of this study suggest that taro may contribute to the prevention of neurodegenerative disease and become a new and safe therapeutic strategy for Parkinson's disease.

• The Journal of Korean Medicine
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• v.29 no.2
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• pp.133-150
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• 2008

Objective: This study was performed to examine Danggui (DG, Angelica gigas Nakai)'s potential activity for promoting axonal regeneration in the injured peripheral nerve. Methods: Using the sciatic nerve in the rats, DG extract 5 ${\mu}l$(10 mg/ml in 0.5% saline) was dripped into the injury site of the nerve. Results: DG treatment facilitated axonal elongation responses in the distal portion to the injury site. GAP-43 protein levels were upregulated by DG treatment in the injured nerve and also in the DRG, suggesting the induction of GAP-43 expression at gene expression level after nerve injury. Phospho-Erk1/2 protein levels were upregulated in the injured nerve area and also in the DRG, suggesting retrograde transport of phospho-Erk1/2 protein from the injury area to the cell body. Cdc2 protein levels were slightly upregulated by DG treatment. DG treatment increased the number of non-neuronal cells in the distal portion to the injury site. Conclusions: The present data suggest that DG is effective for enhanced axonal regrowth after sciatic nerve injury.