• 제목/요약/키워드: block chain

검색결과 414건 처리시간 0.027초

상 하복신경총 차단을 이용한 골반내 통증관리 (Superior Hypogastric Plexus Blocks for Malignant Pelvic Pain)

  • 강성희
    • The Korean Journal of Pain
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    • 제5권1호
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    • pp.108-112
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    • 1992
  • Pain from pelvic cancer is very difficult to manage because it's vague ness and bilateral nature. Furthermore, nerve blocks in this area are dangerous because sensory afferent nerves from pelvic viscera are adjacent to nerves that regulate bowel and bladder control, and motor nerve of lower extremities'. Bilateral lumbar sympathectomy has been used for malignant pelvic pain with little risk of neurologic complication. However it is not a specific block for pelvic visceral pain, because the lumbar sympathetic chain does not innervate pelvic viscera in a direct manner. Therefore the potentials of lumbar sympathectomy for pelvic visceral pain are attributed to caudad diffusion of neurolytic agents to the smperior hypogastric plexus. I have experienced 3 cases of superior hypogastric plexus neurolysis per se without any significant complications.

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Control of Block Copolymer Microdomain: In-Situ and Real-Time SANS Studies of Polymerization-Induced Self-assembly of Block Copolymer Microdomain Structure

  • Koizumi, Satoshi;Yamauchi, Kazuhiro;Hasegawa, Hirokazu;Tanaka, Hirokazu;Motokawa, Ryuhei;Hashimoto, Takeji
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.71-72
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    • 2006
  • We investigated a simultaneous living anionic polymerization process of isoprene (I) and 4styrene-d_8$ (S) in $benzene-d_6$ as a solvent with sec-buthyllithium as an initiator into polyisoprene(PI)-block-poly($styrene-d_8$)(PS) and the polymerization-induced molecular self-assembling process. This process was observed in-situ by time-resolved small-angle neutron scattering (SANS) experiment. The SANS profiles measured exhibited three time regions, where (i) the selective growth of PI chains occurs; (ii) the living chain ends switch from isoprenyllithium to styryllithium, and (iii) the SANS exhibited the polymerization induced disorder-to-order transition and order-to-order transition.

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Living Anionic Polymerization of Isocyanates

  • Lee, Jae-Suk
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.198-198
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    • 2006
  • We have identified sodium benzanilide (Na-BA), sodium diphenyl amine (Na-DPA) and sodium deoxibenzoin (Na-DB) as very efficient initiators for the living anionic polymerization of HIC. It has a slow propagation rate with the additive function of chain end protection, offering in the process a perfect control over MW and MWD. The well-defined amphiphilic coil-rod, coil-rod-coil, and rod-coil-rod block-copolymers of PHIC and P2VP with controlled architecture have been synthesized for the first time with ${\sim}100\;%$ yields. The resulting block copolymers showed lamellar film, donuts, solid and hollow micelles, by simply varying the solvents and the block compositions.

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모듈형 NVIDIA Jetson TX2 임베디드 제품에서의 블록체인 적합성 (Block Chain Conformance in Modular NVIDIA Jetson TX 2 Embedded Products)

  • 최효현;이경영;손동원
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2018년도 제58차 하계학술대회논문집 26권2호
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    • pp.297-298
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    • 2018
  • 본 논문에서는 모듈형 NVIDIA Jetson TX2 임베디드 제품에서 채굴을 통해 블록체인의 적합성 여부를 보인다. 범용성과 적합성의 평가기준은 TPS (Transactions Per Second), 블록생성시간(Block Generation Time)과 확정시간(Confirmation Time)이다. 채굴 준비 시 TX2 임베디드 제품의 특성상 하드웨어 드라이버를 자립적으로 설치 할 수 없기 때문에 HOST PC와 함께 사용하였다. HOST PC는 TX2 제품과 호환성이 높은 OS인 Ubuntu 14.04를 사용했으며, 하드웨어 드라이버 설치를 위해 NVIDIA 공식 TX2 제품 소프트웨어 중 JetPack 3.1 Release Version 을 사용하였다. 코인은 이더리움(Ethereum), 라이트코인(Litecoin)과 제트캐쉬(Zcash) 총 3종 코인으로, 채굴 시 나온 결과물로 TX2 제품에서 블록체인의 적합성 여부를 보였다.

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Polymeric Micelle Formation of Multiblock Copolymer Composed of Poly( $\gamma$-benzyl L-glutamate) and Poly(ethylene oxide)

  • 나재운;정영일;조종수
    • Bulletin of the Korean Chemical Society
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    • 제21권4호
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    • pp.383-388
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    • 2000
  • Multiblock copolymers consisting of poly( g-benzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part (GEG) were synthesized and characterized. GEG polymeric micelles were prepared by the dialysis technique. Particle size distributions based on intensity,volume, and number-average were 22.6 $\pm$ 11.9 nm, 23.5 $\pm$ 4.6 nm, and 23.7 $\pm$ 37 nm, respectively. It was observed that par-ticle size and size distribution of GEG polymeric micelles changed significantly with the choice of initial sol-vent. Transmission electron micrographs (TEM) showed the polymeric micelles to be spherically shaped, with sizes ranging from 20 nm to 40 nm in diameter. Fluorescence spectroscopy measurements suggested that GEG block copolymers wereassociated in water to form polymeric micelles, and the critical micelle concentrations (CMC) value of the block copolymers was 0.0094 g/L. Further evidenceof micelle formation of GEG block copolymers and limited mobility of the PBLG chain in the core ohe micelle was obtained with 1 H NMR in D2O.

환자 익명성 보장을 위한 블록체인 알고리즘 (Block Chain Algorithm to Ensure Patient Anonymity)

  • 조영복;우성희
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2019년도 춘계학술대회
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    • pp.358-362
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    • 2019
  • 본 논문에서는 블록체인 기반의 환자익명성 보장을 위한 알고리즘을 제안하였다. 환자의 익명성과 의사와 환자 사이 연계 불가성 지원을 위해서 신원증명용 주소와 별개로 스텔스 주소를 사용하였다. 또한 의무기록을 사용함에 있어 그 해쉬 값 등 사용 정보를 블록에 입력하여 의무기록의 무결성과 투명성을 보장 한다.

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블록체인을 활용한 Single Sign-On 기반 인증 시스템 (Single Sign-On based Authentication System combined with Blockchain)

  • 임지혁;이명하;이형우
    • 사물인터넷융복합논문지
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    • 제4권2호
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    • pp.13-20
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    • 2018
  • 본 논문은 최근 대두된 신기술인 '블록체인' 기술을 기반으로 'Single-Sign-On'과 'Token 기반 인증 방식'을 접목한 인증 시스템을 제안하였다. Single-Sign-On 기반 인증 방식에 블록체인 기술을 접목하여 '접근제어' 기능과 '무결성'을 제공하였으며, Token 기반 인증 방식을 사용하여 Stateless한 Self-Contained 인증 기능을 제공하였다. 암호화 기반 Token 발급 및 인증 과정을 수행하여 보안성을 높일 수 있었으며, Web Server에 대한 인증 편리성을 제공하였다. 또한 SSO과 Token 기반 인증을 통해 번거로운 인증 과정을 보다 편리하게 개선할 수 있는 방법을 제시하였다.

Electrocardiography as an early cardiac screening test in children with mitochondrial disease

  • Baik, Ran;Chae, Jung-Hyun;Lee, Young-Mock;Kang, Hoon-Chul;Lee, Joon-Soo;Kim, Heung-Dong
    • Clinical and Experimental Pediatrics
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    • 제53권5호
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    • pp.644-647
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    • 2010
  • Purpose: To evaluate myocardial conductivity to understand cardiac involvement in patients with mitochondrial disease. Methods: We performed retrospective study on fifty-seven nonspecific mitochondrial encephalopathy patients with no clinical cardiac manifestations. The patients were diagnosed with mitochondrial respiratory chain complex defects through biochemical enzyme assays of muscle tissue. We performed standard 12-lead electrocardiography (ECG) on all patients. Results: ECG abnormalities were observed in 30 patients (52.6%). Prolongation of the QTc interval (>440 ms) was seen in 19 patients (33.3%), widening of the corrected QRS interval in 15 (26.3%), and bundle branch block in four (7.0%). Atrioventricular block, premature atrial contraction and premature ventricular contraction were seen in two patients each (3.5%) and Wolff-Parkinson-White syndrome in one patient (1.8%). Conclusion: Given this finding, we recommend active screening with ECG in patients with mitochondrial disease even in patients without obvious cardiac manifestation.

비트코인을 활용한 효율적 전자화폐 활성화 방안 (Effective Vitalization Plan of Electronic Cash using Bitcoin)

  • 이준형;이성훈;이도은;김우철;김민수
    • 융합보안논문지
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    • 제16권4호
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    • pp.79-90
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    • 2016
  • 현재 통용되고 있는 '전자화폐'는 기존에 통용되던 실물화폐를 디지털화하여 사용할 뿐 물리적으로 통용되던 화폐를 벗어나지 못하고 있는 실정이다. 특히 비트코인의 경우 발행주체 없이 '채굴'이라는 행위에 의해서만 발행되며, 개인간 거래는 P2P 형태로 '블록체인(BlockChain)'을 통해 거래를 증명하는 형태로 몇몇 국가에서 화폐로써 인정을 받아 제법 활발히 통용되고 있지만, 비트코인이 갖는 특성들 때문에 여러 가지 문제를 안고 있다. 따라서 본 연구에서는 비트코인의 활성화 방안에 있어 정책적, 관리적, 기술적 문제점들에 대한 대안을 제시하고자 한다.

Surface Active Properties and LCST Behavior of Oligo(propylene oxide-block-ethylene oxide) Allyl Ether Siloxane Surfactants in Aqueous Solution

  • Kim, Doo-Won;Lim, Chul-Hwan;Choi, Jae-Kon;Noh, Si-Tae
    • Bulletin of the Korean Chemical Society
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    • 제25권8호
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    • pp.1182-1188
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    • 2004
  • Polydisperse oligo(PO-b-EO) allyl ether siloxane surfactants were synthesized by the hydrosilylation reaction of OMTS with Allyl-oligo(PO-b-EO) series. The surface tension of siloxane surfactants increased with increasing the EO chain length while it decreased with increasing the PO ratio. However, the sedimentation time of the aqueous solution showed opposite trend to the surface tension data. Both the surface tension and sedimentation time of the aqueous solution containing inorganic electrolyte gradually decreased as the content of inorganic electrolyte increased because of the surface arrangement of surfactant molecules. However, they increased with an increase of pH values due to the hydrolysis of the siloxane backbone. The $C_p$ values tended to increase with the increase in the EO chain length and decrease of the PO ratio. It seems that intermolecular interaction between PO/EO block copolymer and water affects the variation of transition temperature.