• Title/Summary/Keyword: Si(IV)

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Synthesis and Evaluation of Antitumor Activity of Novel 1,4-Naphthoquinone Derivatives (IV)

  • Kim Bok Hee;Yoo Jikang;Park Si-Hyun;Jung Jae-Kyung;Cho Hoon;Chung Yongseog
    • Archives of Pharmacal Research
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    • v.29 no.2
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    • pp.123-130
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    • 2006
  • 1,4-Naphthoquinones are widely distributed in nature and many clinically important antitumor drugs containing a quinone moiety, such as anthracyclines, mitoxantrones and saintopin, show excellent anticancer activity. In this study, 2- or 6-substituted 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) and 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) derivatives were synthesized, and their cytotoxic activity against L1210 and P388 cancer cells was examined. Their antitumor activity was also assessed in mice bearing S-180 cells in the peritoneal cavity. In comparison with the DMNQ derivatives, the DHNQ derivatives exhibited more potent bioactivities than the DMNQ derivatives against both L1210 and P388 cells in vitro and S-180 cells in vivo. The $ED_{50}$ values of the DHNQ derivatives against P388 cells were in the range of 0.18-1.81 ${\mu}g/mL$ whereas those of the DMNQ derivatives were in the range of 0.26-40.41 ${\mu}g/mL$. The T/C ($\%$) values of the DHNQ derivatives, 8, 17, 18, 19, and 20, were found to be comparable to or even better than that of adriamycin. It was also observed that the 2-substituted derivatives (8, 19, 20) showed better antitumor activity than the 6-substituted derivatives (7, 17, 18) in the mice bearing S-180 cells in the peritoneal cavity.

Dehydrocoupling of Bis(silyl)alkylbenzenes to Network Polysilanes, Catalyzed by Group 4 Metallocene Combination

  • Kim, Myoung-Hee;Lee, Jun;Moo, Soo-Yong;Kim, Jong-Hyun;Ko, Young Chun;Woo, Hee-Gweon
    • Journal of Integrative Natural Science
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    • v.3 no.1
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    • pp.1-6
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    • 2010
  • Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were synthesized in high yields by the reduction of the corresponding chlorosilanes with $LiAlH_4$ in diethyl ether. The dehydrocoupling of 1 and 2 was performed using group IV metallocene complexes generated in situ from $Cp_2MCl_2$/Red-Al and $Cp_2MCl_2$/n-BuLi (M = Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 ($M_w$ vs polystyrene using GPC) and from 500 to 900 ($M_w$ vs polystyrene using GPC). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble network polymer.

Development of a diagnostic system to detect potato virus T using RT-PCR and nested PCR (감자T바이러스 검정을 위한 RT-PCR 및 Nested PCR 진단시스템 개발)

  • Lee, Si Won;Shin, Yong-Gil;Lee, Jin-Young;Kim, Young-Suk;Yang, Mi Hee;Choi, In-Cheol
    • Korean Journal of Agricultural Science
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    • v.42 no.2
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    • pp.99-103
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    • 2015
  • Potato virus T (PVT) is a plant pathogen in the family Betaflexiviridae, group IV single-stranded positive sense RNA viruses. The major host of PVT is potato, and it has been reported in Ullucus tuberosus, Oxalis tuberosa and Tropaeolum tuberosum. This study aimed at developing reverse transcription (RT)-polymerase chain reaction (PCR) and nested PCR techniques for specific detection of PVT. Finally, Two RT-PCR primer sets were developed and verified. The RT-PCR products were amplified to 734 (PVT RT-PCR primer set 6) and 828 bp (PVT RT-PCR primer set 29) long to detect PVT. The nested PCR primer sets [PVT-N70/C20 ($734{\rightarrow}315bp$) and PVT-N75/C30 ($828{\rightarrow}529bp$)] were developed which are high sensitivity and verification for detection of PVT. Furthermore, a modified-positive control plasmid is use to verify contamination of laboratory in PVT detection. This study supported the diagnose PVT in potato or PVT related hosts.

The Behavior of Electrolytes in Nonaqueous Solutions (IV). Relative Viscosities and Osmotic Coefficients of Alkaline Metal Iodides (물아닌 용액에서의 전해질의 행동에 관한 연구 (제4보). 요오드화알칼리금속의 상대점도와 삼투계수)

  • Si-Joong Kim;Jin-Ho Kim;Kyu-Seong Choi
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.349-354
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    • 1984
  • The relative viscosities and the osmotic coefficients of alkaline metal iodides (NaI, KI, RbI, CsI) in methanol, ethanol, dimethylsulfoxide (DMSO), and sulfolane (TMS) have been measured by Ubbelohde viscometer and vapor pressure osmometry at 45 ∼ $120^{\circ}C.$ The order of A and B coefficients in viscosity for alkaline metal iodides are MeOH > EtOH > TMS > DMSO, and TMS > EtOH > DMSO > MeOH. dB/dT values for the alkaline metal iodides are in the order of NaI > KI > RbI > CsI in the protic solvents, while those for the aprotic solvents are in the reverse order. The order of the osmotic coefficients for the alkaline metal iodides is EtOH > DMSO > MeOH > TMS.

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Preparation of Anatase TiO2 Thin Films with (OiPr)2Ti(CH3COCHCONEt2)2 Precursor by MOCVD

  • Bae, Byoung-Jae;Lee, Kwang-Yeol;Seo, Won-Seok;Miah, Md. Arzu;Kim, Keun-Chong;Park, Joon T.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.11
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    • pp.1661-1666
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    • 2004
  • The reaction of titanium tetraisopropoxide with 2 equiv of N,N-diethyl acetoacetamide affords Ti($O^iPr)_2(CH_3COCHCONEt_2)_2$ (1) as colorless crystals in 80% yield. Compound 1 is characterized by spectroscopic (Mass and $^1H/^{13}C$ NMR) and microanalytical data. Molecular structure of 1 has been determined by a single crystal X-ray diffraction study, which reveals that it is a monomeric, cis-diisopropoxide and contains a six coordinate Ti(IV) atom with a cis($CONEt_2$), trans($COCH_3$) configuration (1a) in a distorted octahedral environment. Variable-temperature $^1H$ NMR spectra of 1 indicate that it exists as an equilibrium mixture of cis, trans (1a) and cis, cis (1b) isomers in a 0.57 : 0.43 ratio at -20$^{\circ}C$ in toluene-$d_8$ solution. Thermal properties of 1 as a MOCVD precursor for titanium dioxide films have been evaluated by thermal gravimetric analysis and vapor pressure measurement. Thin films of pure anatase titanium dioxide (after annealing above 500$^{\circ}C$ under oxygen) have been grown on Si(100) with precursor 1 in the substrate temperature range of 350- 500$^{\circ}$ using a bubbler-based MOCVD method.

Involvement of a Novel Organic Cation Transporter in Paeonol Transport Across the Blood-Brain Barrier

  • Gyawali, Asmita;Krol, Sokhoeurn;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.27 no.3
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    • pp.290-301
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    • 2019
  • Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

A Study of the Mural Paintings in Thai Temples (태국의 불교사찰 벽화에 관한 연구)

  • NOH, Jangsuh
    • SUVANNABHUMI
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    • v.1 no.2
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    • pp.1-20
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    • 2009
  • This research tries to review the history and concepts of Thai temple mural painting. According to the research results, the history of Thai mural painting dates back to the late 14th century when Wat Chedi Chet Taeo in Si Satchanalai was built. The Sinhalese elements embedded in the Sukhothai murals are also found in the Ayuthayan stupa murals made in the early 15th century. The mid 18th century's Burmese invasion into Ayuthaya destroyed most of Buddhist temples in the Kingdom of Ayuthaya and as a result, Buddhist murals of the late Ayuthayan age are hardly found except for some temple murals located outside of the capital. The late Ayuthayan murals are much different from the early Ayuthayan murals in that they are narrative in depicting Jataka and the life of Lord Buddha. This classical mural painting culminated in the age of Rama III of Bangkok Dynasty. His successor Rama IV undertook westernized reforms which influenced the area of traditional mural painting. Consequently, new western style Buddhist mural paintings were produced while themes of mural painting were enlarged to the other subjects such as historical recording of royal and social events. This trend continued in the age of Rama V but the development of Thai Buddhist mural painting discontinued after the death of Rama V due to the rapid westernization and decrease of illiteracy. The existing Buddhist murals produced on or before the reign of Rama V are deteriorating and disappearing. The reasons for this are partly because of Thailand's humid climate. However, some social backgrounds such as the lack of concern for preserving old Buddhist murals can not be disregarded. Considering the substantial value of Thai Buddhist murals as a cultural resource in Thai society, it is very urgent to establish appropriate conservation policy for them.

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The Flora of Janggun-bong Region (Yangju-si, Gyeonggi-do) Adjacent to DMZ (DMZ 일원 장군봉(경기도 양주시) 일대의 관속식물상)

  • Jaesang Chung;Jong-Won Lee;Jin-Heon Song;Young-Min Choi;Kyung-Ryul Byun;Hee-Young Gil
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2021.04a
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    • pp.34-34
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    • 2021
  • 과거 식물상에 대한 정보가 없었던 경기도 양주시 장흥면에 위치한 장군봉(425.0 m)의 식물상을 2020년 4월부터 10월까지 총 3회에 걸쳐 조사하였다. 본 조사에서 확인된 조사지 내 관속식물은 양치식물 8과 10속 9종 1변종 10분류군, 나자식물 3과 4속 6종 6분류군, 쌍자엽식물 62과 144속 198종 7아종 16변종 2품종 223분류군, 단자엽식물 6과 29속 38종 1아종 5변종 1픔종 45분류군으로 총 284분류군을 확인할 수 있었다. 장군봉 일대의 특산식물은 은사시나무 (Populus tomentiglandulosa T.B.Lee), 키버들 (Salix koriyanagi Kimura), 병꽃나무 (Weigela subsessilis (Nakai) L.H.Bailey), 백운산원추리 (Hemerocallis hakuunensis Nakai)의 4분류군이 분포하고 있었고 산림청에서 지정한 희귀식물로는 취약종 (VU) 등급의 주목 (Taxus cuspidata Siebold & Zucc.) 1분류군이 확인되었다. 느릅나무 (Ulmus davidiana var. japonica (Rehder) Nakai)를 포함하여 I등급 10종, 함박꽃나무 (Magnolia sieboldii K.Koch) 등 II등급 4종, 병조희풀 (Clematis heracleifolia DC.) 등 III등급 8종, IV등급에 해당하는 바위말발도리 (Deutzia grandiflora var. baroniana Diels) 등 총 25종이 식물구계학적특정종에 속했다. 침입외래식물은 미국자리공 (Phytolacca americana L.), 유럽점나도나물 (Cerastium glomeratum Thuill.), 청비름 (Amaranthus viridis L.) 등 20분류군을 확인할 수 있었고, 생태계교란야생식물인 환삼덩굴 (Humulus japonicus Sieboid & Zucc.), 돼지풀 (Ambrosia artemisiifolia L.), 단풍잎돼지풀 (Ambrosia trifida L.), 미국쑥부쟁이 (Aster pilosus Willd.)의 4분류군이 확인되었다.

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The Flora of Vascular Plants of Mt. Ja-Ung (Gyeong-gi-do, Pa-ju-si) Adjacent to the DMZ (DMZ 일원 자웅산(경기도 파주시) 일대의 관속식물상)

  • Young-Min Choi;Jong-Won Lee;Jin-Heon Song;Kyung-Ryul Byun;Jaesang Chung;Hee-Young Gil
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2021.04a
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    • pp.33-33
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    • 2021
  • 자웅산(264.3m)은 DMZ 접경지역인 경기도 파주시 법원읍에 위치하며, 백두대간 줄기 중 한북정맥을 따라 동쪽으로는 노고산(401m), 서쪽으로는 명학산(220m) 사이에 위치하고 있다. 2020년 4월부터 10월까지 계절별로 1회씩 총 3회 식물상 조사를 진행하였고 화상자료와 증거표본을 확보하였다. 본 조사로부터 자웅산 일대에 자생하는 관속식물은 82과 208속 267종 9아종 22변종 4품종으로 총 303분류군이 확인되었다. 양치식물은 10과 18분류군, 나자식물은 2과 6분류군, 쌍자엽식물이 62과 226분류군, 단자엽식물이 8과 53분류군으로 확인되었다. 개나리(Forsythia koreana (Rehder) Nakai), 백운산원추리(Hemerocallis hakuunensis Nakai), 키버들(Salix koriyanagi Kimura ex Goerz) 등 3과 3분류군의 특산식물이 확인되었다. 침입외래식물로는 가시도꼬마리(Xanthium italicum Moretti), 단풍잎돼지풀(Ambrosia trifida L.), 미국개기장(Panicum dichotomiflorum Michx.), 서양민들레(Taraxacum officinale F.H.Wigg.), 애기망초(Conyza parva Cronquist) 등 7과 23분류군으로 조사되어 조사식물 303분류군의 7.6%를 차지하였다. 환경부 지정 식물구계학적 특정종은 V등급이 미나리냉이(Cardamine leucantha (Tausch) O.E.Schulz), IV등급이 당단풍나무(Acer pseudosieboldianum (Pax) Kom.), 산복사나무(Prunus davidiana (Carrière) Franch.) 등 2분류군, III등급이 금낭화(Dicentra spectabilis (L.) Lem.), 꽃쥐손이(Geranium platyanthum Duthie), 분비나무(Abies nephrolepis (Trautv. ex Maxim.) Maxim.) 등 7분류군이 확인되어 III등급 이상의 특정종은 10분류군으로 파악된다.

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Characteristics of Pinus densiflora-Dominant Community on the Mountain Ridges of the Nakdong-Jeongmaek - Focusing on the Baekbyeongsan, Chilbosan, Baegamsan, Unjusan, Goheonsan - (낙동정맥 마루금 일대의 소나무우점군락 특성 - 백병산, 칠보산, 백암산, 운주산, 고헌산을 중심으로 -)

  • Kang, Hyun-Mi;Park, Seok-Gon;Lee, Sang-Cheol
    • Korean Journal of Environment and Ecology
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    • v.30 no.4
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    • pp.751-761
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    • 2016
  • Since the position of Nakdong-Jeongmaek stretches from south to north, it shows clear changes of the climate compared to other mountain ranges. This study aimed to analyze the characteristics of vegetation in Pinus densiflora-dominant community (PDDC), which typically appeared on the ridge of this area, by each region and community. For this, the PDDCs in five representative areas of Nakdong-Jeongmaek (Baekbyeonsan, Chilbosan, Baegamsan, Unjusan and Goheonsan) were investigated. Communities were divided into four groups based on the characteristics of the growing environment for indicator species among the low vegetation, while the pinus densiflora was dominant on the canopy according to TWINSPAN. In community I, Fraxinus sieboldiana and Rhododendron schlippenbachii were dominant and there was a typical vegetation on the mountain ridge. In community II that was located on the upper slope, there was abundant inflow of sunlight to the inside of the forest which resulted from the disturbance, and it formed the secondary forest where deciduous broadleaf tree species such as Rhus cotinus appeared. Compared to the other communities, community III had a wider range of growing environment and various species of deciduous broadleaf trees appeared, so that changes in the vegetation structure were expected in the future. Finally, with the appearance of Salix hallaisanensis and Betula davurica, community IV are presumed to be located at a relatively high region with bountiful soil moisture. Reviewing by regions, PDDCs in Unjusan and Goheonsan were near big cities such as Pohang-si and Ulsan-si, so that the artificial disturbance resulted in high level of species diversity on a stage of vegetation development and the ages of Pinus densiflora were relatively young. On the other hand, PDDCs showed a stable vegetation status with low level of species diversity in other regions, and the ages of Pinus densiflora were relatively old.