Characterization and multicolor upconversion emission properties of BaMoO₄: Yb³⁺, Ln³⁺ (Ln = Tm, Ho, Tm/Ho) microcrystals

Ray, Schindra Kumar,Kshetri, Yuwaraj K.,Yamaguchi, Tokutaro,Kim, Tae-Ho,Lee, Soo Wohn Elsevier 2019 Journal of solid state chemistry Vol.272 No.-

<P><B>Abstract</B></P> <P>Hydrothermal process was employed to synthesize the Yb<SUP>3+</SUP>/Tm<SUP>3+</SUP>, Yb<SUP>3+</SUP>/Ho<SUP>3+</SUP> and Yb<SUP>3+</SUP>/Tm<SUP>3+</SUP>/Ho<SUP>3+</SUP> doped BaMoO<SUB>4</SUB> octahedron microcrystals (0.50–5.0 µm). The synthesized phosphors have scheelite tetragonal structure. The elemental mapping suggests the uniform distribution of elements in the samples. The oxidation state of samples were investigated by X-ray photoelectron spectroscopy (XPS) which indicates the existence of Ba<SUP>2+</SUP>, Mo<SUP>6+</SUP>, O, Yb<SUP>3+</SUP>, Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> in samples. The presence of rare earth ions was also verified by observation of specific absorption peaks in diffuse reflectance spectra (DRS). The tunable multicolor upconversion (UC) emissions were successfully obtained under 980 nm NIR excitation by precisely adjusting the concentration of rare earth ions. The as prepared sample exhibits blue, green and red emission as a result of energy transfer from the Yb<SUP>3+</SUP> to Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> ions. The power dependent UC emission spectra show the two photonic processes. The energy transfer mechanism from Yb<SUP>3+</SUP> to Tm<SUP>3+</SUP> and Ho<SUP>3+</SUP> was explained <I>via</I> an energy level analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of BaMoO<SUB>4</SUB>: Yb<SUP>3+</SUP>, Ln<SUP>3+</SUP> (Ln = Tm, Ho, Tm/Ho) by hydrothermal process. </LI> <LI> Investigation of upconversion luminescence of phosphors under 980 nm excitation. </LI> <LI> Obtaining the multicolor emission by adjusting doped rare-earth ions concentration. </LI> <LI> Explanation of photonic process and energy transfer mechanism. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Multicolor upconversion emission properties of BaMoO<SUB>4</SUB>: Yb<SUP>3+</SUP>, Ln<SUP>3+</SUP> (Ln = Tm, Ho, Tm/Ho) octahedrons</P> <P>[DISPLAY OMISSION]</P>

Korean Red ginseng prevents endothelial senescence by downregulating the HO-1/NF-κB/miRNA-155-5p/eNOS pathway

Tae-Hoon Kim,Ji-Yoon Kim,Jieun Bae,Young-Mi Kim,Moo-Ho Won,Kwon-Soo Ha,Young-Guen Kwon,Young-Myeong Kim 고려인삼학회 2021 Journal of Ginseng Research Vol.45 No.2

Background: Korean Red ginseng extract (KRGE) has beneficial effects on the cardiovascular system by improving endothelial cell function. However, its pharmacological effect on endothelial cell senescence has not been clearly elucidated. Therefore, we examined the effect and molecular mechanism of KRGE on the senescence of human umbilical vein endothelial cells (HUVECs). Methods: HUVECs were grown in normal or KRGE-supplemented medium. Furthermore, they were transfected with heme oxygenase-1 (HO-1) gene or treated with its inhibitor, a NF-κB inhibitor, and a miR-155-5p mimic or inhibitor. Senescence-associated characteristics of endothelial cells were determined by biochemical and immunohistochemical analyses. Results: Treatment of HUVECs with KRGE resulted in delayed onset and progression of senescence-associated characteristics, such as increased lysosomal acidic β-galactosidase and decreased telomerase activity, angiogenic dysfunction, and abnormal cell morphology. KRGE preserved the levels of anti-senescent factors, such as eNOS-derived NO, MnSOD, and cyclins D and A: however, it decreased the levels of senescence-promoting factors, such as ROS, activated NF-κB, endothelial cell inflammation, and p21 expression. The beneficial effects of KRGE were due to the induction of HO-1 and the inhibition of NF-κB-dependent biogenesis of miR-155-5p that led to the downregulation of eNOS. Moreover, treatment with inhibitors of HO-1, NF-κB, and miR-155-5p abolished the anti-senescence effects of KRGE. Conclusion: KRGE delayed or prevented HUVEC senescence through a signaling cascade involving the induction of HO-1, the inhibition of NF-κB-dependent miR-155-5p biogenesis, and the maintenance of the eNOS/NO axis activity, suggesting that it may protect against vascular diseases associated with endothelial senescence.

하동 출생 시인의 시 세계에 나타난 심상지리적 특성 비교 고찰 - 정공채와 정호승의 시 세계를 중심으로

오태호 ( Oh Tae-ho ) 한국문학이론과 비평학회 2012 한국문학이론과 비평 Vol.56 No.-

본고는 경남 하동 출생 시인인 정공채, 정호승 시인의 시 세계 고찰을 통해 두 시인의 대표적인 시적 형상화 공간인 ‘바다’와 ‘서울’의 심상지리적 특성을 규명하는 데에 그 목적이 있다. 두 시인의 출생지가 같다는 동일성이 존재하지만, 진주 성장, 대구 성장을 거쳐 각각 부산 생활, 서울 생활을 하면서 출생지로부터 멀어짐으로써 두 시인은 서로 다른 심상지리적 표상을 구축하고 있다. 두 시인의 대표적인 공간인 ‘바다’와 ‘서울’이라는 공간적 표상을 중심으로 시 세계를 고찰한 뒤에 두 시인에게 ‘고향’ 모티프가 차지하는 상반된 함의를 규명해 보았다. 정공채 시인은 ‘바다’의 심상지리를 통해 자유와 욕망을 노래한다. 바다는 심신의 자유를 가능케 한 원형 상징에 해당하며 욕망의 몸짓을 풀어놓는 해방의 공간으로 기능한다. 시인에게 바다는 시심을 일깨우는 “무변의 자유”로움을 제공하는 것이다. 정호승 시인은 ‘서울’에서 슬픔의 힘과 서울의 절망을 응시한다. 서울은 사랑과 죽음, 외로움과 눈물을 통해 생이 제공하는 힘겨운 일상의 양면적 의미를 제공한다. ‘서울의 환부’를 노래하는 시인은 가난하고 힘없는 자들의 이미지를 집적하면서 ‘슬픔과 사랑’이라는 서울의 양가성을 노래한다. 두 시인에게 ‘고향 하동’은 출생지로서의 동일성을 내포할 뿐 전혀 다른 심상지리로 형상화된다. 즉 정공채 시인에게는 ‘고향 하동’이 개인사적 체험을 육화하는 ‘장소이자 지역’으로서 상상력의 독자성과 개별성이 강조된다. 반면에 정호승 시인에게 ‘고향 하동’은 부재하는 기표로 존재한다. 즉 인접 공간인 지리산이나 섬진강이라는 ‘자연적 표상’을 통해 환유적 인접성의 공간으로 간접화되어 유추될 수 있을 뿐이다. ‘고향 하동’은 정공채 시인에게는 ‘체험적 실체’로, 정호승 시인에게는 ‘간접화된 기표’로 표출됨으로써 ‘이질적 심상지리’에 해당하는 공간으로 포착된다. ‘하동 출생’ 시인으로서 ‘장소성’을 강조하는 정공채와 ‘장소성’이 부재하는 정호승의 이질적인 시적 태도는 이후 ‘바다’와 ‘서울’이 표상하는 심상지리적 특성을 형상화하는 두 갈래 흐름을 대변한다는 점에서 주목할 가치가 있다. Jeong Kong-Chae and Jeong Ho-Sung come from HaDong. The study definds as embodied-poetic room-’the sea’ and ‘Seoul’- of imaginative geography characteristic through poetry of poets. They equal birthplace however, they express different imaginative geography symbol by distanting from birthplace (both of potes migrate from HaDong to JinJu to Busan, from HaDong to DaeGu to Seoul) Both of poets focus on spatial symbol-’the sea’ and ‘Seoul’ in poetry. And It is definded conflicting implication in motivation about ‘hometown’ For potes, ‘hometown Hang-Dong’ is only involving identity as birthplace while it embodies utterly different geographical imagery. In other words, Jeong Kong-Chae stresses identity and individuation of imagination as not only place but also region expressing personal experience. Meanwhile, ‘hometown HaDong’ exists absent signifier to Jeong Ho-Sung. Thus, Mt. Ji-ri and Riv. Sum-Jin is analogized indirect metalepsis contiguous place through ‘natural symbol’. While, ‘hometown HaDong’ does ‘experiential substance’ to Jeong Kong-Chae , It seizes on place in ‘different imaginative geography’ by expressing ‘indirect signifier’ to Jeong Ho-Sung. It is worth noticing represent forked stream expressing imaginative geography characteristic named ‘regionality(spatial symbol-’the sea’ and ‘Seoul’in poetry)’ different poetic attitude - Jeong Kong-Chae stresses ‘placeness’,Jeong Ho-Sung stresses absent ‘placeness’ as poets ‘birth of HaDong’.

Induction of heme oxygenase-1 protects against podocyte apoptosis under diabetic conditions

Lee, Sang Choel,Han, Seung Hyeok,Li, Jin Ji,Lee, Sun Ha,Jung, Dong-Sub,Kwak, Seung-Jae,Kim, Seung Hye,Kim, Dong Ki,Yoo, Tae-Hyun,Kim, Jin Hyun,Chang, Se-Ho,Han, Dae Suk,Kang, Shin-Wook International Society of Nephrology 2009 Kidney international Vol.76 No.8

Heme oxygenase-1 (HO-1) is an anti-oxidant enzyme normally upregulated in response to oxidant injury. Here we determined the role of HO-1 in podocyte apoptosis in glomeruli of streptozotocin-treated rats and in immortalized mouse podocytes cultured in media containing normal or high glucose. HO-1 expression, its activity, the ratio of Bax/Bcl-2 protein, and active caspase-3 fragments were all significantly higher in isolated glomeruli of diabetic rats and in high glucose–treated podocytes. These increases were inhibited by zinc protoporphyrin treatment of the rats or by HO-1 siRNA treatment of the podocytes in culture. The number of apoptotic cells was also significantly increased in the glomeruli of diabetic rats and in high glucose–treated podocytes. Inhibition of HO-1 accentuated the increase in apoptotic cells both in vivo and in vitro. Our findings suggest that HO-1 expression protects against podocyte apoptosis under diabetic conditions.

Combined Gene Therapy with Hypoxia-Inducible Factor-1α and Heme Oxygenase-1 for Therapeutic Angiogenesis

Bhang, Suk Ho,Kim, Ju Hee,Yang, Hee Seok,La, Wan-Geun,Lee, Tae-Jin,Kim, Ga Hee,Kim, Hyun Ah,Lee, Minhyung,Kim, Byung-Soo Mary Ann Liebert 2011 Tissue engineering. Part A Vol.17 No.7

<P>Transfection with either hypoxia-inducible factor-1α (HIF-1α) or heme oxygenase-1 (HO-1) gene can induce neovascularization in ischemic tissues. Although expression of transfected HIF-1α gene occurs rapidly, the expressed HIF-1α protein degrades quickly, limiting its therapeutic efficacy. Meanwhile, expressed HO-1 protein does not rapidly undergo degradation, but gene expression occurs a couple of days after transfection, resulting in apoptosis and a delay in angiogenesis in ischemic tissues at the incipient period of HO-1 gene transfection. We hypothesize that combined delivery of HIF-1α and HO-1 gene will enhance antiapoptosis and neovascularization in ischemic tissue compared with HIF-1α or HO-1 single-gene therapy. To test this hypothesis, ischemic mouse hindlimbs were treated with HIF-1α and/or HO-1 gene therapy. The combined gene therapy proved superior to both single-gene therapies, resulting in rapid expression of HIF-1α gene and long-term maintenance of expressed HO-1 protein. The apoptosis in the ischemic region was significantly less, and angiogenic growth factor secretion and angiogenesis were greater in the combined gene therapy than in either of the single-gene therapies. Our results suggest that a combined gene therapy of HIF-1α and HO-1 enhances the transfection of both genes and improves angiogenesis compared with either single-gene therapy.</P>

Like-charge ion pairs of hydronium and hydroxide in aqueous solution?

Ghosh, Manik Kumer,Choi, Tae Hoon,Choi, Cheol Ho The Royal Society of Chemistry 2015 Physical Chemistry Chemical Physics Vol.17 No.25

<P>The like-charge ion pairings of hydronium and hydroxide were investigated using both ab initio cluster calculations and QM/MM-MD aqueous simulations. While only a two-water-bridged H3O+(H2O)(2)H3O+ is found in hydronium cluster calculations, three clusters of HO-(H2O)(2)HO-, HO-(H2O)(3)HO- and HO-(H2O)(4)HO- are stable dihydroxide aggregates. In addition, an interesting yet very stable parallelogram structure of [O-H...H-O](2-) without any bridging water was also discovered using QM/MM-MD simulations. According to our analysis, its unique structure reduces the electrostatic repulsion and allows stable coordination with solvents at the same time. In conclusion, hydroxide can formstronger like-ion pairs than hydronium in aqueous solutionmostly due to its versatile coordination ability with solvents.</P>

청심연자탕(淸心蓮子湯)으로 호전된 뇌내출혈에 고혈압이 동반된 태음인 환자 치험 1례

오정민,엄태민,최고은,허종원,유호룡,설인찬,김윤식,Oh, Jeong-Min,Eom, Tae-Min,Choi, Ko-Eun,Heo, Jong-Won,Yoo, Ho-Ryong,Seol, In-Chan,Kim, Yoon-Sik 대한중풍순환신경학회 2014 대한중풍.순환신경학회지 Vol.15 No.1

■ Objectives The purpose of this case study is to report that a hypertension with intracerebral hemorrhage of tae-eumin was treated with 'Cheongsim Yeunja-tang' and then the symptoms were improved and blood pressure was decreased. ■ Methods Although the patient who had hypertension with intracerebral hemorrhage took antihypertension drugs, intermittent increase of blood pressure was shown. We diagnosed him as Tae-eumin and treated with Cheongsim Yeunja-tang. We daily checked blood pressure and evaluated the symptoms. ■ Results After the treatment with Cheongsim Yeunja-tang, blood pressure was decreased and symptoms were improved. ■ Conclusion The result shows Cheongsim Yeunja-tang has antihypertensive effect and improve hypertension symptoms of Tae-eumin patient with intracerebral hemorrhage.

Fluoxetine and Sertraline Attenuate Postischemic Brain Injury in Mice

Tae Kyeong Shin,Mi Sun Kang,Ho Youn Lee,Moo Sang Seo,Si Geun Kim,Chi Dae Kim,Won Suk Lee 대한생리학회-대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1Ձ (HIF-1Ձ) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1Ձ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.

Synthesis of Sr Doped HoCrO3 Solid Solution Systems and Their Electrical Properties

PARK, SUNG HO,Kwon, Tae Yun 한국공업화학회 2000 Journal of Industrial and Engineering Chemistry Vol.6 No.4

Ho_(1-x)SrxCrO₃ systems, with perovskite structures, were synthesized for x=0, 0.05, 0.1, 0.2 at 1300 ℃ under atmospheric pressure. The results of X-ray analysis reveals that these prepared systems forms orthorhombic structures. Also, the HoCrO₃ systems which were doped with Sr cations on the site of Ho cations, exhibited a linear increase in their cell volume. It was found that the lattice parameter and reduced volume increased as the doping level of Sr^(2+) increased. From the measurements of D.C conductivity, the activation energy obtained from the conductivity dependence on temperature was 0.18 eV. The conduction mechanism would appear to be the hopping model of electron conduction.

교량기초 지반의 액상화 가능성 평가

추진호,강태호,조성호 中央大學校 建設環境硏究所 2002 環境科學硏究 Vol.13 No.1

흙의 액상화저항 산정은 많은 지질 공학적 조사에 있어서 중요한 단계이다. 일반적으로 Seed-Idriss가 제안한 간편법이 널리 사용되고 있다. 간편법은 N치를 이용하는 것이 보편적이 나, 근래에는, SHAKE(Schnabel, et al., 1972)와 같은 지반응답해석 프로그램의 결과인 깊이별 최대 가속도를 이용한 수정 Seed and Idriss 방법이 선호되는 추세이다. 또한, 자갈이 있는 곳이나 시추가 불가한 지역에서 전단파 속도를 이용한 Andrus and Stokoe 방법이 새롭게 도입되어 사용하고 있다. 본 연구에서는 7개 지역의 철도교량 기초지반에 대하여 수정 Seed-Idris s방법과 Andrus and Stokoe 방법으로 액상화 가능성을 평가하였다. 그리고, 해석 결과에 대한 신뢰성을 향상시키기 위하여 현장에서의 전단파 속도는 SASW 실험과 전단 탄성계수 및 재료의 감쇠비는 공진주 실험 결과를 이용하였다. 수정 Seed-Idriss 방법과 Andrus and Stokoe 방법은 비슷한 결과를 나타내었으며, 국내 지반에 처음으로 적용된 Andrus and Stokoe 방법이 신뢰성 있는 액상화 평가 결과를 제시하는 것으로 확인되었다. 따라서, 전석층, 자갈층 등이 특히 많은 교량기초 지반의 경우 Andrus and Stokoe 방법(신뢰성있게 액상화 가능성을 평가할 수 있는 방법이라고 판단되었다. Evaluation of the liquefaction resistance of soils is an important step in many geotechnical investigations. Generally, the counts of the Standard Penetration Test(SPT). However, recently, the modified Seed-Idriss simplified procedure uses the peak ground surface acceleration, which was obtained by the site response analysis. A new procedure by Andrus and Stokoe uses shear-wave velocities to evaluate the liquefaction resistance of soil. The method is useful specially at sites where boring activity is net allowed. In this study, liquefaction susceptibility analysis for the subsurface of railroad bridge was performed both by the modified Seed-Idriss simplified procedure and by the Andrus-Stokoe procedure. Furthermore incorporated to make a better evaluation of liquefaction analysis. Consequently, both methods turned out to give the same results far the liquefaction susceptibility, which implies that the Andrus-Stokoe procedure proved to be a reliable and useful approach in the river-bed geothechnical site with gravels, cobles etc.