• Title/Summary/Keyword: Resonance structures

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Purification and Identification of Antioxidant Compounds from Dolichos lablab L. Seeds (백편두의 항산화 물질 분리 및 동정)

  • Kwon, Nam Woo;Kim, Jae Yeon;Cho, Yong Beom;Hwang, Bang Yeon;Kim, Jun Gu;Woo, Sun Hee;Lee, Moon Soon
    • Korean Journal of Medicinal Crop Science
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    • v.27 no.6
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    • pp.419-426
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    • 2019
  • Background: This study aimed to identify antioxidant compounds from the seeds of Dolichos lablab L. by bioassay-guided isolation and recrystallization. Methods and Results: The water layer of D. lablab L. seed extract inhibits intracellular reactive oxygen species (ROS) expressing the 2',7'-dichlorofluorescein diacetate (DCF-DA), Cu/Zn superoxide dismutase (SOD) and catalase genes, as determined by quantitative real-time PCR (qRT-PCR). Two compounds were purified from the water layer of the seeds of D. lablab L. using column chromatography and prep-high performance liquid chromatography (HPLC). Using nuclear magnetic resonance (NMR) and electrospray Ionization mass spectrometry (ESI-MS), their chemical structures were identified as 5-[(2-acetyl-2,3-dihydro-1H-indazol-1-yl)carbonyl]-4,5-dihydro-3H-furan-2-one (C14H14N2O4) and stachyose. Conclusions: Two active antioxidant compounds were purified from the seed extract of D. lablab L. seed extract and the structures of these compounds were identified as C14H14O4N2 and stachyose.

Nano Convergence Systems for Smart Living

  • Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.55-55
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    • 2015
  • Today, engineers are facing new set of challenges that are quite different from the conventional ones. Information technologies are rapidly commoditizing while the paths beyond the current roadmaps became uncertain as various technologies have been pushed to their limits. Along with these changes in IT ecosystems, grand challenges such as global security, health, sustainability, and energy increasingly require trans-disciplinary solutions that go beyond the traditional arenas in STEM (Science, Technology, Engineering and Mathematics). Addressing these needs is shifting engineering education and research to a new paradigm where the emphasis is placed on the consilience for holistic and system level understanding and the convergence of technology with AHSD (arts, humanities, social science, and design). At the center of this evolutionary convergence, nanotechnologies are enabling novel functionalities such as bio-compatibility, flexibility, low power, and sustainability while on a mission to meet scalability and low cost for smart electronics, u-health, sensing networks, and self-sustainable energy systems. This talk introduces the efforts of convergence based on the emerging nano technology tool sets in the newly launched School of Integrated Technology and the Yonsei Institute of Convergence Technology at Yonsei International Campus. While the conventional devices have largely depended upon the inherent material properties, the newer devices are enabled by nanoscale dimensions and structures in increasingly standardized and scalable fabrication platform. Localized surface plasmon resonance in 0 dimensional nano particles and structures leads to subwavelength confinement and enhanced near-field interactions enabling novel field of metal photonics for sensing and integrated photonic applications [1,2]. Unique properties offered by 1 dimensional nanowires and 2 dimensional materials and structures can enable novel electronic, photonic, nano-bio, and biomimetic applications [3-5]. These novel functionalities offered by the emerging nanotechnologies are continuously finding pathways to be part of smart systems to improve the overall quality of life.

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Conformation of cyclo-[Gln-Trp-Phe- $\beta$Ala-Leu-Met], a NK-2 Tachykinin Receptor Antagonist (NK-2의 Antagonist인 cyclo-[Gln-Trp-Phe- $\beta$Ala-Leu-Met]의 형태에 관한 연구)

  • Ha, Jong Myung
    • Journal of the Korean Chemical Society
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    • v.43 no.5
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    • pp.540-546
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    • 1999
  • Solution conformation of cyclo-($Gln^1-Trp^2-Phe^3-{\beta}Ala^4-Leu^5-Met^6$), new NK-2 antagonist in dimethyl sulfoxide solution, has been determined by the use of two-dimensional nuclear magnetic resonance spectroscopy combined with simulated annealing calculations. The peptide exhibited converged structures with the atomic root-mean-square difference for the backbone atoms ($N,\;C^{\alpha},\;C'$) of all residues being 0.02${\AA}$ in the 25 annealed structures. The analysis of the structures indicated that the cyclic peptide has three intramolecular hydrogen bonds between $Met^6NH$ and ${\beta}Ala^4CO$, ${\beta}Ala^4NH$ and $Met^6CO$, $Phe^3NH$ and $Met^6CO$, and contain a type-I ${\beta}$-turn with Gln and Trp and ${\gamma}$-turn with Leu. The addition of an extra methylene group to Gly, i.e. P-Ala residue, may relax some unfavorable restraints in the cyclic backbone structure, hence enabling an additional hydrogen bond, which results in stabilizing one conformation.

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Giant Lipoma in the Lateral Neck Causing Internal Jugular Vein Deformity (내경정맥의 변형을 유발한 거대 경부 지방종)

  • Jun Ho, Choi;Sang Seong, Oh;Kwang Seog, Kim;Jae Ha, Hwang;Sam Yong, Lee
    • Korean Journal of Head & Neck Oncology
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    • v.38 no.2
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    • pp.29-32
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    • 2022
  • Lipoma is one of the most common benign soft tissue tumors. However, giant lipomas compressing and deforming the neurovascular structure rarely occur in the lateral neck. A 70-year-old man visited our outpatient clinic for treatment of a visible painless neck mass that had been identified 2 years prior. Neck magnetic resonance imaging revealed that a 10 × 9 × 4 cm fatty mass located between the sternocleidomastoid and sternohyoid muscles invaded the carotid sheath. Under general anesthesia, the mass was excised without damage to the adjacent neurovascular structures. Upon histopathological examination, the mass was identified as a lipoma. During the surgery, enlargement of the internal jugular vein was observed under the resected mass. However, on ultrasound examination, the function of the internal jugular vein was evaluated as good. No recurrence or neurological and vascular complications were reported during a 6-month follow-up after the surgery. As a giant lipoma located in the deep layer of the lateral neck can deform important cervical structures, its impact on the surrounding structures should be carefully assessed preoperatively to minimize the rate of possible complications.

Characterization and performance of post treated PVDF hollow fiber membrane

  • Eman S. Sayed;Hayam F. Shaalan;Magda I. Marzouk;Heba A. Hani
    • Membrane and Water Treatment
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    • v.15 no.2
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    • pp.79-88
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    • 2024
  • Modification of Polyvinylidene fluoride (PVDF) hollow fiber membranes (HFMs) characteristics and performance were investigated via post treatment using different oxidants. sodium hypochlorite (NaOCl), hydrogen peroxide (H2O2) and potassium persulfate (KPS). Fourier transform infrared (FTIR) and Proton nuclear magnetic resonance (1H-NMR) results revealed no structural differences after post treatment. Cross-sectional micrographs show finger-like structures at the outer and inner walls of the HFMs and sponge-like structures in middle, where NaOCl and KPS post treated fibers exhibited a decrease in finger-like structures in addition to aggregates appearing on the surface, consequently leading to an increase in the surface roughness (Ra) from 48 nm to 52.8nm and 56 nm, respectively. Hydrogen peroxide post treatment only was observed to decrease the water contact angle from 98° to 81.4°. It was also observed that the elongation at break and the modulus deceased after NaOCl post treatment from 34.5 to 28.5% and from 19.3 Mpa to 16.6 Mpa, respectively. Moreover, pure water flux after H2O2 post treatment increased from 87.8 LMH/bar to 113 LMH/bar at 0.45 bar, while no changes were detected for the methylene blue dye rejection (74%) between raw and hydrogen peroxide post treated fibers at the same pressure. According to the findings hydrogen peroxide post treated PVDF HFMs have the most uniform surfaces, with almost no alterations in structural and mechanical properties or porosities with enhanced hydrophilicity and pure water flux maintaining appropriate rejection. Therefore, it is considered an efficient surface modifying agent for UF/NF membranes or low-pressure separators.

Chemical Constituents and Bioactivity of Curcuma aeruginosa Roxb.

  • Saad, Suhaila Md.;Lajis, Nordin Hj.;Rahmani, Mawardi;Muse, Radzali;Yusuf, Umi Kalsom;Riyanto, Sugeng;Sukari, Mohd. Aspollah Hj.
    • Natural Product Sciences
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    • v.13 no.3
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    • pp.175-179
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    • 2007
  • Phytochemical study on the rhizomes of Curcuma aeruginosa has yielded three sesquiterpenes, which were identified as zedoarol (1), curcumenol (2) and isocurcumenol (3). The structures of the compounds were determined by Infrared Spectroscopy (IR), Nuclear Magnetic Resonance (1D and 2D NMR) and Mass Spectroscopy (MS). The crude extracts and pure compounds obtained were tested against pathogenic microbes and cancer cell lines

Preparation and Characterization of PEG/PLA Multiblock and Triblock Copolymer

  • Zhao, Hesong;Liu, Zhun;Park, Sang-Hyuk;Kim, Sang-Ho;Kim, Jung-Hyun;Piao, Longhai
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1638-1642
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    • 2012
  • A series of poly (lactic acid) (PLA) and poly (ethylene glycol) (PEG) tri and multiblock copolymers with relatively high molecular weights were synthesized through the coupling reaction between the bis(acyl chloride) of carboxylated PLA and mono or dihydroxy PEG. The coupling reaction and the copolymer structures were monitored by nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The melting temperature (Tm) of PEG blocks decreased with the presence of PLA sequences attaching to PEG blocks. The CMC values were determined to be 10-145 mg/L depending on the length of PLA and PEG blocks and the structure of the block copolymers.

A visual investigation of non-premixed flame behavior under acoustic excitation (음향 가진 하에서 비예혼합 화염거동에 관한 가시화 연구)

  • Lee, Kee-Man;Oh, Sai-Kee
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.871-877
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    • 2001
  • Experimental study was conducted to investigate the effects of axial forcing on the flame structures near the nozzle exit of non-premixed flame. The most notable observation is that the direction of vortical motions is changed at some ranges, according to the increase of excitation amplitude. Especially, the elongation flame and the phenomenon of In-burning are always occurred when the vortical motion turnabout. In an analysis of the flame/flow visualization by means of direct photography and RMS technique, a plausible explanation can be made that above phenomena are related only to the amplitude of phase average velocity between the instantaneous velocity elements of excited flow.

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Parkinsonism after Cyanide Intoxication: A Case Report (시안화칼륨 중독으로 인해 발생한 파킨슨씨병 1례)

  • Suh, Joo-Hyun;Eo, Eun-Kyung
    • Journal of The Korean Society of Clinical Toxicology
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    • v.2 no.2
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    • pp.137-140
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    • 2004
  • Acute cyanide poisoning is usually the result of attempted suicide which is often lethal within minutes or leads to a very poor prognosis after delayed and inadequate treatment. It affects the cerebral structures with the highest oxygen requirement, such as the basal ganglia, the cerebral cortex. We experienced a-45-year-old man who ingested Potassium Cyanide. He was stuporous. In 25 minutes, respiratory arrest developed and cardiopulmonary resuscitation was done. After return of spontaneous circulation, he admitted to intensive care unit, and conservative treatment was started. The clinical status was improved by degrees, but he couldn't perform daily activity like before. Minimal limitation of movement and memory deficit were left. In magnetic resonance imaging, which taken at the 11th day after admission, there were both basal ganglia and folia of cerebellum abnormality.

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Synthesis and Antitumor Activity of Pt(ll) Complexes Containing Ethylenediamine (에칠렌디아민을 배위자로 한 백금(II) 착체의 합성과 항암효과)

  • Lee, Kyung-Tae;Jung, Jee-Chang;Roh, Young-Soo
    • Journal of Pharmaceutical Investigation
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    • v.24 no.4
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    • pp.245-250
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    • 1994
  • An attempt was made to develop new water-soluble antitumor Pt(ll) complexes containing ethylenediamine, and their structures were determined by infrared spectroscopy, $^{13}C$ nuclear magnetic resonance and elemental analysis. Their antitumor activities in vitro against L-1210, p-388 leukemia cells and M-14 melanoma cells were investigated and acceptable antitumor activity was found as compared with cisplatin.

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