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        검색결과 41

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pharmaceutical products occurring in freshwater bodies create numerous problems for the water bodies owing to their bio-toxic nature. In order to remove such pharmaceutical pollutants, a novel Er-doped Bi4O5Br2/ g-C3N5 nanocomposite was prepared by one-pot synthesis and applied for the photocatalytic removal process. The Er ions doped on the surface of Bi4O5Br2/ g-C3N5 nanocomposite exhibited 97% degradation of tetracycline in 60 min under visible light irradiation, which is higher than pure g-C3N5 and Bi4O5Br2 photocatalysts. The improved photocatalytic properties are attributed to the outstanding visible light harvesting capacity and quick charge carrier separation efficiency which greatly reduced the recombination rate in the heterojunctions. Based on radical trapping experiments, the •O2 −, h+ and •OH radicals played a prominent role in the photodegradation reactions under visible light. Finally, the ternary Er-doped Bi4O5Br2/ g-C3N5 nanocomposite is effectively recyclable with quite a stable photocatalytic removal rate. This work enables a new perspective on the rational design of rare-earth-based nanocomposites for various pharmaceutical pollutants treatment processes.
        4,000원
        2.
        2021.02 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        본 논문은 중국 내몽고 화림격이 벽화고분의 벽화 주제와 구성 방식에 관한 것이다. 화림격이 벽화고분은 1971년에 내몽고 화림격이현에서 발견된 대표적인 동한대 벽화고분 중 하나로 풍부한 벽화와 방제가 발견된다. 화림격이 벽화고분의 벽화 주제로는 크게 현실 세계와 천상 세계로 나눌 수 있다. 현실 세계를 표현한 주제로는 묘주도, 거마행렬도, 역사고사인물도, 건축도, 악무백희도, 속리도, 푸주 및 농경 등이 있고 천상 세계를 표현한 주제로는 상서도, 사신도, 운문 등이 있다. 묘주의 생활과 관련한 벽화는 전실과 중실, 후실에 모두 주요하게 등장한다. 본 연구는 벽화의 내용뿐만 아니라 묘장 구조에 따른 벽화 위치를 살펴보아 벽화의 전체적인 흐름을 알아보고자 한다. 전실에는 묘주의 정치적 지위를 나타내며, 중실에는 묘주가 한가롭게 지내는 모습과 역사고사 인물도, 거마행렬도 등이 그려져 있다. 후실에는 묘 주의 사적인 생활 모습이 그려져 있다. 나머지 세 개의 측실에는 묘주를 위해 생산 활동하고 있는 시자들의 모습이 주로 묘사되어 있고, 목조의 기둥과 두공, 운문이 그려져 있다. 이처럼 화림격이 벽화고분에는 묘주의 일평생이 담겨 있으며, 정치적 신분과 경제적 부 등을 벽화를 통해 과시하고 있다. 고분 구조에 따라 벽화의 배치를 살펴보면, 전실의 벽화는 중축선을 기준으로 좌우대칭적이다. 중실은 좌에서 우로 향하는 대각선을 기준으로 서벽과 북벽에는 역사고사인물도가 주요하게 그려져 있고, 거마행렬도는 남벽과 동벽에 그려져 있다. 후실의 벽화는 여러 주제가 등장하는 전실과 중실과 다르게 묘실 전체에 묘주의 사적 생활 모습이라는 공통된 주제의 벽화를 보여준다.
        6,600원
        3.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sestrin-2 (SESN2) as a stress-metabolic protein is known for its anti-oxidative effects as a downstream factor of PERK pathways in mammalian cells. However, the expression patterns of SESN2 in conjunction with the UPR signaling against to ER stress on porcine oocyte maturation in vitro, have not been reported. Therefore, we confirmed the expression pattern of SESN2 protein, for which to examine the relationship between PERK signaling and SESN2 in porcine oocyte during IVM. We investigated the SESN2 expression patterns using Western blot analysis in denuded oocytes (DOs), cumulus cells (CCs), and cumulus-oocyte complexes (COCs) at 22 and 44 h of IVM. As expected, the SESN2 protein level significantly increased (p < 0.01) in porcine COCs during 44 h of IVM. We investigated the meiotic maturation after applying ER stress inhibitor in various concentration (50, 100 and 200 μM) of tauroursodeoxycholic acid (TUDCA). We confirmed significant increase (p < 0.05) of meiotic maturation rate in TUDCA 200 μM treated COCs for 44 h of IVM. Finally, we confirmed the protein level of SESN2 and meiotic maturation via regulating ER-stress by only tunicamycin (Tm), only TUDCA, and Tm + TUDCA treatment in porcine COCs. As a result, treatment of the TUDCA following Tm pre-treatment reduced SESN2 protein level in porcine COCs. In addition, SESN2 protein level significantly reduced in only TUDCA treated porcine COCs. Our results suggest that the SESN2 expression is related to the stress mediator response to ER stress through the PERK signaling pathways in porcine oocyte maturation.
        4,000원
        5.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effect of activation method on the endoplasmic reticulum (ER) stress induction, apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus (ES) (E), 2) ES+10 μM Ca-ionophore (A23187) treatment (EC), 3) ES+2 mM 6-dimethylaminopurine (6-DMAP) treatment (ED), or 4) ES+A23187 and 6-DMAP treatments (ECD). Parthenogenetic embryos were sampled to analyze x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptosis genes at 3 h after ES and the 1-cell and blastocyst stages. In the EC group, the band intensity of spliced Xbp1 (Xbp1s) mRNA was higher than those of the other groups at the 3 h and 1-cell stage, and higher than that of the E group at the blastocyst stage. Four ER stress-associated genes were expressed at the highest level in the EC group and weakly expressed in the ED group at 3 h after activation. However, most of the genes were highly expressed at the 1-cell and blastocyst stages with some variation in the EC and ECD groups. Expression of Bcl-2-associated X protein (Bax) and caspase-3 mRNA was significantly higher in the EC group than in the other groups at all development stages. The developmental rates to the blastocyst stage were higher in the ED and ECD groups than in the E and EC groups. These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by the activation method and subsequently lead to the apoptosis of embryos.
        4,000원
        6.
        2016.10 구독 인증기관·개인회원 무료
        This study was conducted to examine the effects of activation methods on the ER stress induction and subsequent apoptosis and in vitro development of porcine parthenogenetic embryos. Porcine in vitro matured oocytes were activated by four activation methods; 1) electric stimulus(ES) with two DC pulses of 1.25 kV/cm, for 30 ㎲ (E), 2) ES + 10 μM Ca-ionophore (A23187) treatment for 5 min (EC), 3) ES + 2 mM 6-dimethylaminopurine treatment for 3 h (ED), or 4) ES + A23187 + 6-DMAP (ECD). After activation, parthenogenetic embryos were in vitro cultured in PZM-3 medium and sampled to analyze the x-box binding protein 1 (Xbp1) mRNA, ER stress-associated genes and apoptotic genes at 3 h post ES and the 1-cell and blastocyst stages. The un-spliced and spliced x-box binding protein 1 (Xbp1) mRNA were confirmed by RT-PCR. Also ER stress-associated genes, such as the C/EBP homologous protein (CHOP), binding protein (BiP), activating transcription factor 4 (ATF4) and glucose-regulated protein 94 (GRP94), and apoptotic genes were analyzed by real-time quantitative RT-PCR (RT-qPCR). The band intensities of spliced Xbp1 (Xbp1s) mRNA was higher in the EC group than other three groups at 3 h and the 1-cell stage, while it was higher in the ED groups compared with E group at the blastocyst stage. Four ER stress-associated genes were showed the highest expression in the EC group and weakly expressed in the ED group at 3 h. However, most of those genes were highly expressed in EC and ECD groups at the 1-cell and blastocyst stages with some variation. The expressions of Bcl-2-associated X protein (Bax) and caspase-3 mRNAs were significantly higher in EC group than other three groups at all stages. The developmental rate to the blastocyst stage was higher (p<0.05) in ED and ECD groups (32.1±3.8 to 34.6±2.2%) than that of E group (26.1±3.9%). These results suggest that the intracellular ER stress of parthenogenetic porcine embryos is affected by activation method and subsequently lead to the apoptosis of embryos.
        7.
        2016.04 구독 인증기관·개인회원 무료
        Western flower thrips, (Pergande) (Thysanoptera: Thripidae) have been recognized as serious pests worldwide. Commercially available chemical pesticides challenges against the resistance of the pest and safety to consumers. Herein we investigated the usability of soil-treatment of entomopathogenic Beauveria bassiana (Bb) ERL isolates in tomatoes. Bb-egfp was highly virulent to western flower thrips in laboratory conditions and colonized in soil, which provided a chance for western flower thrips larvae to contact the colonized fungal mass. In a glasshouse trial, Bb ERL836 and Bb ERL1578 granule (GR) were applied to soil surface and mixed well, and five females were infested to each pot of tomato 3 days after the application. The two treatments significantly reduced thrips population in tomatoes 20 and 40 days post applications, comparable to the control efficacy of clothianidin granule (GR) formulation. In the following field trial, the two ERL fungal treatments showed 69.2% and 61.5% of control efficacy, which were similar to that of clothianidin GR (76.9%). This work suggests that applied B. bassiana colonized in soil well and thrips larvae easily contacted the fungal mass, which possibly enabled the control strategy to be alternative way to the chemical control.
        8.
        2015.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Pb1-xMoO4:Er3+/Yb3+ phosphors with various doping concentrations of Er3+ and Yb3+ (x = Er3++Yb3+, Er3+ = 0.05, 0.1, 0.2, and Yb3+ = 0.2, 0.45) are successfully synthesized using a microwave sol-gel method, and the up-conversion photoluminescence properties are investigated. Well-crystallized particles, which are formed after heat treatment at 900 oC for 16 h, exhibit a fine and homogeneous morphology with particle sizes of 2-5 μm. Under excitation at 980 nm, the Pb0.7MoO4: Er0.1Yb0.2 and Pb0.5MoO4:Er0.05Yb0.45 particles exhibit a strong 525 nm emission band, a weak 550 nm emission band in the green region, and a very weak 655 nm emission band in the red region. The Raman spectra of the doped particles indicate the presence of strong peaks at higher and lower frequencies induced by the disordered structures of Pb1-xMoO4 through the incorporation of the Er3+ and Yb3+ ions into the crystal lattice, which results in the unit cell shrinkage accompanying the new phase formation of the MoO4-x group.
        4,000원
        9.
        2015.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        YNbO4:Yb3+/Er3+ is synthesized using a solid-state reaction process with a LiCl flux. The effects of the Er/(Yb+Er) ratios (REr) on the up-conversion (UC) and down-conversion (DC) spectra are investigated. The XRD data confirm that the Yb3+ and Er3+ ions are fully substituted for the Y3+ sites. The UC emission spectra activated by 980 nm consists of green and red emission bands, which originate from the Er3+ ions through an energy transfer (ET) process from Yb3+ to Er3+. The UC emission intensity depends on the REr value, and the findings demonstrate that REr ≤ 0.14 is suitable for an effective UC process. The DC emission spectra under 269 nm radiation of the synthesized powders exhibits not only a strong blue emission assigned to the [NbO4]3− niobates, but also green peaks that originate from the Er3+ ions through an ET process between [NbO4]3− and Er3+.
        4,000원
        10.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적: Iodine을 수송매체로 사용한 화학수송법으로 성장시킨 CdS, CdS : Co2+ 및 CdS : Er3+단결정의 광학적 특성연구를 하였다. 방 법: CdS, CdS : Co 및 CdS : Er 단결정을 성장시키기 위하여 고순도(99.9999 %)의 cadmium, sulfur 를 mole비로 칭량하고 수송물질로 iodine(순도 99.99%)을 함께 준비된 석영관 안에 넣고, 석영관 내부의 진 공을 5×10-6torr로 유지하면서 봉입하여 성장용 ampoule을 만들었다. 단결정을 성장시키기 위하여 시료 출발 측을 900 ℃, 성장 측을 700 ℃로 하여 7일간 성장시켰다. 성장된 단결정에서 iodine 을 제거하기 위하여 출발 측의 전원을 차단하고 성장 측의 온도를 250℃에서 10 시간동안 유지하여 전원을 끊고 실온까지 서냉하여, CdS, CdS : Co 및 CdS : Er단결정을 성장시켰다. 성장된 단결정의 결정구조는 X-ray diffractometer를 사용하여 X선 회절선을 측정하였고, 광흡수 특성은 UV-VIS-NIR spectrophotometer 로 측정하였다. 결과 및 고찰: XRD로 측정한 X선 회절무늬 peak 해석으로부터 구한 CdS 및 CdS : Co2+(2mole%) 단결정의 결정구조는 defect chalcopyrite 구조이었으며 CdS : Er3+(2mole%) 단결정은 hexagonal 구조였다. 에너지 띠 간격은 직접 전이형 밴드구조를 나타냈다. 결 론: 성장된 CdS 및 CdS : Co2+(2mole%) 단결정의 결정구조는 defect chalcopyrite 구조이었으며, 격자 상수는 CdS 단결정의 경우 a = 4.139Å, c = 6.716Å이였고, 불순물로 cobalt를 첨가한 CdS : Co2+(2mole%) 단결정의 경우 a = 4.141Å, c = 6.720Å이였으며, 또한 erbium을 첨가한 CdS : Er3+(2mole%) 단결정의 구조 는 hexagonal 구조이었으며, 격자상수는 a = 4.135Å, b = 4.135Å, c = 6.706Å이었다. 298K에서 순수한 CdS 단결정의 에너지 띠 간격은 2.422e V이었고, 불순물로 전이금속인 cobalt(2mole%) 첨가할 때 에너지 띠 간격은 2.331e V, 또한 희토류금속인 erbium(2mole%) 첨가한 경우 에너지 띠 간격은 2.230e V 이었다.
        4,000원
        11.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We pathologically investigated the effects of water irrigation during Er:YAG laser irradiation on wound healing in mouse skin. Fifty-one 6-week-old ICR male mice were used in the present study. Dermal wounds were generated on the skin of the backs using the Er:YAG laser at 100 mJ/pulse and 10 Hz with (4 ml/min) or without (control) water irrigation. Mice were then sacrificed on 0, 1, and 3 days after laser irradiation, and the crust of the skin and thickness of the thermal coagulation layer were evaluated pathologically. The epidermis extended faster in the water irrigation group than in the control group on 1 day. The epidermis with keratinized layers became thicker and the crust had completely detached after 3 days in the water irrigation group. The thermal coagulation layer was thinner in the water irrigation group than in the control group. Apoptotic cell death was prominent in the control group. Detachment of the crust was observed after 3 days in 50% of the water irrigation group and 20% of the control group. These results demonstrated that Er:YAG laser irradiation with water irrigation promoted faster wound healing
        4,000원
        14.
        2012.09 구독 인증기관 무료, 개인회원 유료
        The key regulators of apoptosis are the interacting protein of the Bcl-2 family. Bcl-2, an important member of this family, blocks cytochrome C release by sequestering pro-apoptotic BH3-only proteins such as Bid, Bad, Bax and Bim. The pro-survival family members (Bcl-2, Bcl-XL, Bcl-W) are critical for cell survival, since loss of any of them causes cell death in certain cell type. However, its role during early porcine embryonic development is not sufficient. In this study, we traced the effects of Bcl-2 inhibitor, ABT-737, on early porcine embryonic development. We also investigated several indicators of developmental potential, including gene expression (apoptosis-related genes) and apoptosis, which are affected by ABT-737. Porcine embryos were cultured in the PZM-3 medium with or without ABT-737 for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without ABT-737 (14.7±3.0 vs 30.3±4.8%, p<0.05). TUNEL assay showed that the number of containing fragmented DNA at the blastocyst stage increased in the ABT-737 treated group compared with control (4.7 vs 3.7, p<0.05). The mRNA expression of the pro-apoptotic gene Bax increased in ABT-737 treated group (p<0.05), whereas expressions of the anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-XL, Bcl-W) decreased (p<0.05). Also, expressions of the ER stress indicator genes (GRP78, XBP-1 and sXBP-1) increased in ABT-737 treated group (p<0.05). In conclusion, Bcl-2 is closely associated with of apoptosis- and ER stress-related genes expressions and developmental potential in pig embryos.
        4,000원
        16.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Er을 첨가한 ZnS:Mn 형광체를 1000℃에서 4시간 고상반응법으로 소결하여 제조하였다. 결정 구조 및 광 특성은 XRD, PL 그리고 SEM을 통하여 분석하였다. XRD 결과, ZnS:Mn 형광체는 hexagonal 구조가 나타났고, Er의 농도가 증가함에 따라 Er2O3 구조가 관찰되었다. ZnS:Mn 형광체의 평균입자 크기는 약 15㎛였고, Er 첨가와 함께 ZnS:Mn, Er 형광체의 입자 크기는 감소하였다. 580nm 발광 피크는 ZnS:Mn, Er 형광체에서 Mn2+ 이온의 4T1→6A1으로의 전이에 의한 것이다. Er을 0.5mol% 첨가한 형광체의 발광 세기는 Er을 첨가하지 않은 ZnS:Mn 형광체보다 높았다. ZnS:Mn, Er 형광체에서 발광 세기의 증가는 Er3+에서 Mn2+로의 에너지 전이에 의한 것으로 생각된다.
        4,000원
        19.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        二合은 두 개의 漢字로 梵語의 복성모 음절을 표음하는 방법이다. 두 개의 漢字 중 첫 번째 글자는 성모가 두 번째 글자는 전체 독음이 표음에 이용된다. 전통적인 표음법인 反切과 비교할 때 두 번째 글자의 전체 독음이 표음이 사용된다는 점이 다르다. 二合에 사용된 글자들의 결합 양상을 보면 이미 알려진 대로 경향성을 보여주는데 그것은 첫째, 첫 번째 漢字가 폐음절일 경우 그 韻尾는 梵語의 두 번째 聲母와 유사하거나 일치하는 경우가 많다. 둘째, 첫 번째 漢字가 개음절이면 그 모음은 梵語의 주요모음과 유사하거나 일치하는 경우가 많다. 셋째, 梵語의 聲母가 s ś c j 등 치음 또는 경구개음인 경우 二合에 사용된 漢字의 주요모음은 -i인 경우가 많다. 이런 경향 이외에 자음과 모음 ṛ이 결합된 음절을 音譯할 경우에도 二合이 사용된다. ṛ은 일반적으로 모음으로 분류되나 음성학적 구조로 보면 자음과 모음이 혼합된 형태이고 실제 발음 시 모음적 색채가 실현되기 때문에 音譯 과정에서 단순한 모음이 아닌 자음-모음 형식으로 인식되어 그러한 현상이 생긴 것으로 추정된다. 중국어 對譯語와 梵語 어휘를 비교해 볼 때 그 음운이 잘 대응되지 않는 경우가 있다. 이는 對譯의 대상이 되었던 언어가 梵語가 아닌 다른 언어, 예를 들면 팔리어나 토카리안어 등이었기 때문일 가능성이 있다. 또한 梵語와 기타 언어 자체의 음운 변화를 고려해야 할 필요도 있다. 이런 부분에 대해서는 향후 좀 더 세밀한 연구가 있어야 할 것으로 생각된다.
        4,300원
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