• 제목/요약/키워드: thermal treatment.

검색결과 2,720건 처리시간 0.029초

Neural Ablation and Regeneration in Pain Practice

  • Choi, Eun Ji;Choi, Yun Mi;Jang, Eun Jung;Kim, Ju Yeon;Kim, Tae Kyun;Kim, Kyung Hoon
    • The Korean Journal of Pain
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    • 제29권1호
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    • pp.3-11
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    • 2016
  • A nerve block is an effective tool for diagnostic and therapeutic methods. If a diagnostic nerve block is successful for pain relief and the subsequent therapeutic nerve block is effective for only a limited duration, the next step that should be considered is a nerve ablation or modulation. The nerve ablation causes iatrogenic neural degeneration aiming only for sensory or sympathetic denervation without motor deficits. Nerve ablation produces the interruption of axonal continuity, degeneration of nerve fibers distal to the lesion (Wallerian degeneration), and the eventual death of axotomized neurons. The nerve ablation methods currently available for resection/removal of innervation are performed by either chemical or thermal ablation. Meanwhile, the nerve modulation method for interruption of innervation is performed using an electromagnetic field of pulsed radiofrequency. According to Sunderland's classification, it is first and foremost suggested that current neural ablations produce third degree peripheral nerve injury (PNI) to the myelin, axon, and endoneurium without any disruption of the fascicular arrangement, perineurium, and epineurium. The merit of Sunderland's third degree PNI is to produce a reversible injury. However, its shortcoming is the recurrence of pain and the necessity of repeated ablative procedures. The molecular mechanisms related to axonal regeneration after injury include cross-talk between axons and glial cells, neurotrophic factors, extracellular matrix molecules, and their receptors. It is essential to establish a safe, long-standing denervation method without any complications in future practices based on the mechanisms of nerve degeneration as well as following regeneration.

Effect of Curing and Compression Process on the Drug Release of Coated Ion-Exchange Resin Complexes

  • Jeong, Seong-Hoon;Wang, Hun-Sik;Koo, Ja-Seong;Choi, Eun-Joo;Park, Ki-Nam
    • Journal of Pharmaceutical Investigation
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    • 제41권2호
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    • pp.67-73
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    • 2011
  • Ion exchange resins can be one of the good carriers for sustained drug release. However, the sustained release may not be enough only with themselves and hence film coating with rate controlling polymers can be applied to have a further effect on the drug release. Due to the environmental and economic issues of organic solvent for the polymer coating, aqueous polymeric systems were selected to develop dosage forms. Among the many aqueous polymeric dispersions for the film coating, EC (ethylcellulose) based polymers such as Aquacoat$^{(R)}$ ECD and Surelease$^{(R)}$ were evaluated.A fluid-bed coating was applied as a processing method. The drug release rate was quite dependent on the coating level so the release rate could be modified easily by changing different levels of the coating. The drug release rate in the Aquacoat$^{(R)}$ coated resin particles was strongly dependent on curing, which is a thermal treatment to make homogeneous films and circumvent drug release changes during storage. After dissolution test using the compressed tablets in which the coated resin particles are contained, inhomogeneous coating and even pores could be observed showing that the mechanical properties of EC were not resistant to granulation and compaction process. However, when tablets were prepared in different batches, the release profiles were almost identical showing the feasibility of the coated resin particle as incorporated into the tablet formulation.

열변성 단백질이 결합된 음이온성 리포솜의 혈장 내 안정성 및 세포 내 이입 평가 (Stability in Plasma and Intracellular Uptake of Thermally Denatured Protein-coated anionic Liposomes)

  • 이미정;황인영;김성규;정석현;정서영;성하수;조선행;신병철
    • Journal of Pharmaceutical Investigation
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    • 제39권6호
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    • pp.423-429
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    • 2009
  • Liposomes have been used as one of the efficient carriers for drug delivery. In this study, anionic liposomes of which surface was modified by using both electrostaic interaction between anionic liposomes and cationically charged BSA molecules at lower pH than isoelectric point (pI) of BSA and denaturation of the BSA-coated liposomes by thermal treatment. The thermally denatured BSA-coated liposomes (DBAL) had mean particle diameter of 125.2${\pm}$1.7 nm and zeta potential value of -22.4${\pm}$4.5 mV. Loading efficiency of model drug, doxorubicin (DOX), into liposomes was 83.0${\pm}$2.6%. Results of in vitro stability study of DBAL in blood plasma showed that the mean particle diameter of DBAL 400 did not increase in blood plasma and adsorption of plasma protein was much less than plain or anionic liposomes. Intracellular uptake of DBAL 400 evaluated by confocal microscopy observation was higher than that of PEG liposomes.

열처리 시 S/Se 분말 비율에 따른 Cu2ZnSnSe4 (CZTSSe) 박막의 합성 및 특성 평가 (Studies on Effect of S/Se Ratio on the Properties of Cu2ZnSn(SxSe1-x)4 (CZTSSe) Thin Films by Sulfo-Selenization of Stacked Precursor Thin Films)

  • 강명길;;홍창우;김진혁
    • Current Photovoltaic Research
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    • 제2권4호
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    • pp.177-181
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    • 2014
  • $Cu_2ZnSn(S_xSe_{1-x})_4$ (CZTSSe) absorber thin films were prepared on Mo coated soda lime glass substrates by sulfo-selenization of sputtered stacked Zn-Sn-Cu precursor thin films. The Zn-Sn-Cu precursor thin films were sulfo-selenized inside a graphite box containing S and Se powder using rapid thermal processing furnace at $540^{\circ}C$ in Ar atmosphere with pre-treatment at $300^{\circ}C$. The effect of different S/Se ratio on the structural, compositional, morphological and electrical properties of the CZTSSe thin films were studied using XRD (X-ray diffraction), XRF (X-ray fluorescence analysis), FE-SEM (field-emission scanning electron microscopy), respectively. The XRD, FE-SEM, XRF results indicated that the properties of sulfo-selenized CZTSSe thin films were strongly related to the S/Se composition ratio. In particular, the CZTS thin film solar cells with S/(S+Se)=0.25 shows best conversion efficiency of 4.6% ($V_{oc}$ : 348 mV, $J_{sc}$ : $26.71mA/cm^2$, FF : 50%, and active area : $0.31cm^2$). Further detailed analysis and discussion for effect of S/Se composition ratio on the properties CZTSSe thin films will be discussed.

Detoxification of Eucheuma spinosum Hydrolysates with Activated Carbon for Ethanol Production by the Salt-Tolerant Yeast Candida tropicalis

  • Ra, Chae Hun;Jung, Jang Hyun;Sunwoo, In Young;Kang, Chang Han;Jeong, Gwi-Taek;Kim, Sung-Koo
    • Journal of Microbiology and Biotechnology
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    • 제25권6호
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    • pp.856-862
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    • 2015
  • The objective of this study was to optimize the slurry contents and salt concentrations for ethanol production from hydrolysates of the seaweed Eucheuma spinosum. A monosaccharide concentration of 44.2 g/l as 49.6% conversion of total carbohydrate of 89.1 g/l was obtained from 120 g dw/l seaweed slurry. Monosaccharides from E. spinosum slurry were obtained by thermal acid hydrolysis and enzymatic hydrolysis. Addition of activated carbon at 2.5% (w/v) and the adsorption time of 2 min were used in subsequent adsorption treatments to prevent the inhibitory effect of HMF. The adsorption surface area of the activated carbon powder was 1,400-1,600 m2/g and showed selectivity to 5-hydroxymethyl furfural (HMF) from monosaccharides. Candida tropicalis KCTC 7212 was cultured in yeast extract, peptone, glucose, and high-salt medium, and exposed to 80, 90, 100, and 110 practical salinity unit (psu) salt concentrations in the lysates. The 100 psu salt concentration showed maximum cell growth and ethanol production. The ethanol fermentations with activated carbon treatment and use of C. tropicalis acclimated to a high salt concentration of 100 psu produced 17.9 g/l of ethanol with a yield (YEtOH) of 0.40 from E. spinosum seaweed.

방기(Sinomenium acutum)의 물추출물이 주요 장내 미생물의 생육에 미치는 영향 (Effects of the Water-extract of Sinomeniiacuti Radix(Sinomenium acuturn) on the Growth of Some Intestinal Microorganisms)

  • 신옥호;유시승;이완규;신현경
    • 한국미생물·생명공학회지
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    • 제20권5호
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    • pp.491-497
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    • 1992
  • 한약재로부터 장내의 대표적 유해균인 Clostridium perfringes의 생육을 억제시키는 소재를 탐색한 결과 방기 물추출물에서 강력한 항균활성을 발견하였다. 방기추출물의 항균활성은 pH1부터 pH13까지의 범위에서 안정하였으며 121'C에서 15분간의 열처리 에서도 활성이 유지되었다. 방기 추출물은 Cl. perfringens, Cl.paraputrificum, Cl.ramosum 및 Cl.butyricum 등 실험에 사용한 모든 Clostridium속균의 생육을 강력하게 억제하였다. 그리고 Clostridium 이외의 주요 장내균에 대한 영향을 조사한 결과 Bif.bifidium, Bacteroides fragilis 및 Eubacterium limosum에 대해서는 역시 그 생육을 억제하였으나, Bif. adolescesnits, Bif.infantis, Bif.longum, E.cloi, Enterococcus faecalis 그리고 Staphylococcus aureus에 대해서는 생육억제 효과가 크게 나타나지 않았다. 반면 Lactobacillus acidophilus와 Bif.animalis에 대해서는 생육촉진효과를 보여주었다.

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통각유발물질에 의한 척수후각세포의 반응에 미치는 Clonidine의 영향 (Effect of Clonidine on the Changes in Dorsal Horn Cell Activity Induced by Chemical Algogenics)

  • 이광훈;김진혁;신홍기;김기순
    • The Korean Journal of Physiology
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    • 제22권2호
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    • pp.245-257
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    • 1988
  • The present study was undertaken to investigate the effect of clonidine on the response of the dorsal horn cells to intra-arterially administered bradykinin $(BK:40{\mu}g)$ and $K^+(4mg)$ in spinal cats and cats with intact spinal cord. The change in the activities of low threshold (LT), high threshold (HT) and wide dynamic range (WDR) cells induced by BK and $K^+$ were determined before and after treatment of animals with clonidine. Also studied was mechanism of inhibitory action of clonidine on the responses of dorsal horn cells to the chemical algogenics. Number of WDR cell responded to intra-arterially administered BK and $K^+$ was greater in spinal animals than in cats with intact spinal cord. Following administration of BK or $K^+$ no change was observed in the activity of LT cell whereas activity of HT cell increased invariably. The increased response of HT cell to BK and $K^+$ was markedly suppressed by clonidine. On the other hand, such inhibitory actions of clonidine were almost completely blocked by yohimbine. The majority of WDR cells were activated by $K^+$ while response of WDR cells to BK was diverse (excitatory, inhibitory or mixed). These results indicate that clonidine inhibits responses of the dorsal horn cells not only to thermal or mechanical stimulations but also to chemical algogenics, and that the inhibitory action of clonidine is generally mediated through excitation of ${\alpha}_2-adrenoreceptors$.

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Cn/In 비에 따른 $CuInS_2$ 박막의 특성에 관한 연구 (A Study on Properties of Cu/In ratio on the $CuInS_2$ thin film)

  • 양현훈;김영준;소순열;정운조;박계춘;이진;정해덕
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.261-262
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    • 2006
  • $CuInS_2$ thin films were synthesized by sulpurization of Cu/In Stacked elemental layer deposited onto glass Substrates by vacuum furance annealing at temperature 200[$^{\circ}C$]. And structural and electrical properties were measured in order to certify optimum conditions for growth of the ternary compound semiconductor $CuInS_2$ thin films with non-stoichiometry composition. $CuInS_2$ thin film was well made at the heat treatment 200[$^{\circ}C$] of SLG/Cu/In/S stacked elemental layer which was prepared by thermal evaporator, and chemical composition of the thin film was analyzed nearly as the proportion of 1:1:2. Physical properties of the thin film were investigated at various fabrication conditions substrate temperature, annealing and temperature, annealing time by XRD, FE-SEM and hall measurement system. At the same time, carrier concentration, hall mobility and resistivity of the thin films was $9.10568{\times}10^{17}[cm^{-3}]$, 312.502 [$cm^2/V{\cdot}s$] and $2.36{\times}10^{-2}[{\Omega}{\cdot}cm]$, respectively.

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석유화학 공장에서 VOCs 제거시설 설치사례 연구 (A Study on Installation of Removal Device for Volatile Organic Compounds from Petrochemical Plant)

  • 김석택
    • 환경위생공학
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    • 제15권2호
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    • pp.95-101
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    • 2000
  • 산업의 고도화에 따른 경제성장으로 인류의 삶의 질은 많이 좋아졌지만 경제활동으로 인한 각종 환경 오염물질은 상대적으로 많이 배축된 것이 사실이다. 특히 대기오염물질의 주 요인이 되고있는 질소산화물과 아황산가스 등 많은 오염물질이 있지만 최근 더욱더 문제가 되고있는 것이 휘발성 유기화합물질로써 대기중의 탄화수소 화합물의 총칭으로 광 화학 옥시던터와 오존 등으로 인한 대기오염으로 인체에 미치는 영향이 아주 심각하며, 발생장소도 대규모 석유화학 장치산업의 원유를 정제하는 정제공정에서부터 저유소 및 중간 제품공정, 그리고 소비자가 직접 접하는 전국각지에 산재되어 있는 주유소 등에서 많은 량의 휘발성 유기화합물질이 발생되고 있다. 이에 대한 대책으로 정부차원에서 우선 대규모 석유화학단지를 휘발성 유기화합물질 배출저감을 위한 종합대책지역으로, 전남 여천지역은 1996. 9. 20일, 울산지역은 1997. 7. 1일에 지정고시 하였다. 울산지역의 경우 당초 대상물질이 47개 항목에서 시행초기에 보완적인 차원에서 크실렌 및 초산 등 일부물질이 수정된 31개 항목으로 변경고시 되었으며, 이에 대해 사업장에서는 해당물질에 따른 처리시설을 설치 가동 중에 있다. 그러나 휘발성 유기화합물질의 발생조건과 발생량, 각 물질의 혼합시 안전성문제 등이 공정조건상 일정하지 않아 방지시설 선정설치에 많은 에로사항이 있었다. 기존의 시설에 방지시설을 추가한다는 것은 화학공장 특성상 여러 가지 조건이 있으며, 그 동안 많은 시행착오를 하면서 설치하였다. 그러나 일부시설은 아직도 완벽한 방지효과를 얻기에는 부족하므로 향후 계속적인 기술 및 설비투자와 관리대책이 보완되어야 할 것으로 사료된다.

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Si 분산 조직의 p형 $\beta-FeSi_2$ 열전재의 제조 및 특성(l)-제조 조건에 따른 미세조직의 변화- (Preparation and Characterization of P-Type Thermoelectric $\beta-FeSi_2$ Containing Dispersed Si Phase(l)-Microstructural Evolution with Processing Conditions-)

  • 민병규;김일호;이동희
    • 한국재료학회지
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    • 제8권7호
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    • pp.584-590
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    • 1998
  • $(Fe_{0.98}Mn_{0.02})_xSi_2(x{\leq$}1) 조성으로, 용융법으로 제조한 $\alpha$-$Fe_2Si_5$상의 잉곳을 730~85$0^{\circ}C$에서 4~20시간 열처리하거나, 기계적 합금화로 제조한 $\varepsilon$-FeSi과 Si상으로 구성된 분말을 760~85$0^{\circ}C$에서 10분간 가압통전소결하므로써 $\beta$-$FeSi_2$기지상에 Si이 분산된 미세조직을 얻을 수 있었다. 조성, 열처리 온도와 소결 온도에 따라 Si 분상의 크기와 간격이 각기 0.05~0.27$\mu\textrm{m}$와 0.2~0.6$\mu\textrm{m}$ 범위에서 변화하였다. 이와 같은 Si 분산상에 의해 $\beta$-$FeSi_2$의 격자 열전도도가 감소되어 성능지수가 향상될 수 있을 것으로 기대된다.

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