• 제목/요약/키워드: PHE

검색결과 542건 처리시간 0.032초

후염성 폴리프로필렌 섬유 제조(II) (PP-PHE Blend Fiber)

  • 정재훈;손태원
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1996년도 춘계학술발표회 논문집
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    • pp.47-52
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    • 1996
  • PP-PHE blends were prepared by mechanical blending using relatively high moecular weight polyhydrozyether(PHE) and popypropylene polymers. PP-PHE blends were prepared and characterized for the purpose of obtaining a dycable PP fibers with the composition of less than 10 wt.% of PHE. 1)yeable PP fibers were acquired through the melt spinning of the PP-PHE blend of comprising less than 10 wt.% of PHE. The resultant fibers had tensile strength of 2~3 g/d, elongation of 330~600%, initial modulus of 22~46 g/d and yield stress of 1.0 g/d, and exhibited markedly improved dyeing ability such as higher absorbance, higher dye adsorption and deeper shade than those of pure PP fiber.

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E. coli 유래 pheA 유전자의 되먹임제어 저항성 돌연변이의 구축과 그 단백질의 생화학적 특성 연구 (Development of the feedback resistant pheAFBR from E. coli and studies on its biochemical characteristics)

  • 카오틴팟;이상현;홍광원;이성행
    • 미생물학회지
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    • 제52권3호
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    • pp.278-285
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    • 2016
  • E. coli의 PheA 단백질은 chorismate mutase and prephenate dehydratase (CMPD) 활성을 가지며 마지막 산물인 페닐알라닌에 의하여 되먹임제어가 되는 생합성 경로의 주요 조절 효소 중의 하나이다. 그러므로, 이 PheA 단백질은 필수 아미노산 중의 하나인 페닐알라닌의 대량 생산에 이용하기 위한 단백질 공학의 타겟이 될 수 있다. 이러한 목적으로 PheA 단백질의 마지막 생산물인 페닐알라닌에 의한 되먹임저해 저항성 유전자원을 선별하였다. 이 유전자의 산물인 $PheA^{FBR}$은 118번째 류신이 페닐알라닌으로 치환되었고, 기질인 prephenate에 대한 친화도가 야생주단백질과 비교하여 약 3.5배 정도 높았다. $PheA^{FBR}$은 세포내에서 축척되어져 되먹임저해를 하는 페닐알라닌 농도에서(약1 mM와 10 mM)에서도 50%와 40%의 활성을 유지 하고 있었고, 페닐알라닌 존재하에서 기질의 결합 성향이 협동적(cooperative) 모드에서 단독적(hyperbolic) 모드로 전환되었다. 이는 기존 연구와 비교해 볼 때, 이 돌연변이 부위는 이 융합기능 효소인 PheA 단백질의 새로운 조절 부위의 존재를 암시 한다. 효소 동력학적 결과는 PheA 단백질의 되먹임저해 저항성 획득이 아미노산 돌연변이에 의한 단백질 구조의 변화 유도에 의한 것으로 생각된다. 더 나아가, 본 연구에서 선별된 돌연변이 유전자는 생물전환법을 이용한 필수아미노산 생산에 산업적으로 응용 가능성이 있다.

계면확산에 의한 Poly(hydroxy ether) 코팅된 탄소섬유의 계면접착력 변화 연구 (Effect of Diffusion on the Interfacial Adhesion of Poly(hydroxy ether) Coated Caron Fibers)

  • 강현민;윤태호
    • Composites Research
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    • 제12권6호
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    • pp.15-21
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    • 1999
  • 비닐에스테르 수지와 탄소섬유의 계면접착력 향상을 위하여 탄소섬유에 물에 분산된 carboxy modified poly(hydroxy ether) (C-PHE)와 수용성 고분자인 poly(hydroxy ether ethanol amine) (PHEA) 및 비수용성인 poly(hydroxy ether) (PHE) 로 코팅하였다. 고분자로 코팅된 탄소섬유와 수지의 계면전단강도는 micro-droplet 시편을 제조하여 측정하였으며,각 시료마다 30개 이상의 시편을 사용하였다. 접착기구 규명을 위하여 코팅재로 사용된 고분자와 비닐에스테르 수지와 계면에서 확산현상을 고찰하였으며, 접착성 시험 후 탄소섬유의 표면을 SEM을 이용하여 분석하였다. PHE와 C-PHE코팅으로 탄소섬유의 계면전단강도가 크게 증가하였으며, 이는 이들 고분자의 비닐에스테르에 대한 우수한 용해도(solubility)때문으로 보여진다. 하지만 용해도가 낮은 PHEA코팅은 접착력 향상에 효과가 없었다.

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Activity Profiles of Linear, Cyclic Monomer and Cyclic Dimer of Enkephalin

  • Kim, Dong-Hee;Hong, Nam-Joo
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.261-269
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    • 2012
  • The cyclic dimers of enkephalin were isolated as minor components during the solution synthesis of the corresponding cyclic monomers. The ratio of cyclic dimer to monomer was approximately 1:4 from the percent of yields. In the receptor binding assay of two cyclic dimmers, ($Tyr_2-C[D-Glu-Phe-gPhe]_2$ 6, $Tyr_2-C[D-Asp-Phe-gPhe-rLeu]_2$ 8), both analogs exhibited the high preference for ${\delta}$ receptor compared to monocyclic counterparts. In the nociceptive activity, both showed about 5 times less potent than the cyclic monomers. The repeated synthesis of 14-membered cyclic analog, Tyr-C[D-Glu-Phe-gPhe-D-rLeu] 14, which was known as having three distinct cis-trans isomers, gave rise to apparently different conformational analog arousing only trans isomer. In the receptor binding assay, it showed tremendously high selectivity toward ${\mu}$ receptor $({\delta}/{\mu}=160)$.

배관 강성을 고려한 소형 공정열교환기 시제품에 대한 탄성 고온구조해석 (Elastic High-temperature Structural Analysis on the Small Scale PHE Prototype Considering the Pipeline Stiffness)

  • 송기남;강지호;홍성덕;박홍윤
    • 한국압력기기공학회 논문집
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    • 제7권3호
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    • pp.48-53
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    • 2011
  • A PHE (Process Heat Exchanger) is a key component required to transfer heat energy of $950^{\circ}C$ generated in a VHTR (Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. A small-scale PHE prototype made of Hastelloy-X is being tested in a small-scale gas loop at Korea Atomic Energy Research Institute. In this study, as a part of the evaluation on the high-temperature structural integrity of the small-scale PHE prototype, we carried out macroscopic high-temperature structural analysis of the small-scale PHE prototype under the gas loop test conditions considering the pipeline stiffness.

Burkholderia sp. D5에 의한 phenanthrene과 pyrene 분해 (Degradation of Phenanthrene and Pyrene by Burkholderia sp. D5)

  • 김태정;조경숙;류희욱
    • 미생물학회지
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    • 제39권4호
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    • pp.267-271
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    • 2003
  • Polycyclic aromatic hydrocarbons(PAHs)를 분해하는 Burkholderia sp. D5를 유류 오염 토양으로 분리하였고, PAHs의 분해특성을 조사하였다. 분리균주는 유일 탄소원으로 phenanthrene(Phe)을 이용하여 생장이 가능하였고, pyrene (Pyr)을 유일 탄소원으로 이용하여 생장하지는 못하였으나 yeast extract(YE)를 공기질로 첨가해 준 조건에서는 Pyr를 분해할 수 있었다. 분리 균주의 PAH 분해속도는 YE, peptone 및 glucose의 첨가에 의해 향상되었으며, 특히 YE 첨가 효과가 가장 우수하였다. 무기염배지(BSM)에 215 mg-Phe/L와 1 g-YE/L를 첨가한 조건에서 Burkholderia sp. D5의 비생장속도(0.28/h)와 Phe 분해속도(29.30 ${\mu}mol$/L/h)는 YE를 첨가하지 않은 조건에서 얻은 비생장속도(0.02/h)와 Phe 분해속도(12.00 ${\mu}mol$/L/h)의 각각 10배 및 2배였다. Phe를 기질로 공급한 경우 최대 비생장속도(${\mu}$_max)와 최대 Phe분해속도(V_max)는 각각 0.34 h-1 및 89 ${\mu}mol$/L/h 이었고. Pyr을 기질로 공급한 경우 ${\mu}$_max와 V_max는 각각 0.27 h-1 및 50 ${\mu}mol$/L/h이었다. Phe 혹은 Pyr 단독 기질하에서 분해속도와 비교 하였을 때(29.30 ${\mu}mol$-Phe L/h, 9.58 ${\mu}mol$-Pyr L/h), 두 기질의 혼합조건에서 Phe와 Pyr 분해속도는 각각 2.20 및 2.18 ${\mu}mol$ L/ h로 저하되었다. Burkholderia sp. D5 균주는 토양에서 Phe와 Pyr을 분해할 수 있었는데, Phe와 Pyr 분해속도는 각각 20.03 및 1.09 ${\mu}mol$ L/h 이었다.

일부 사업장에서 나타난 배치전건강진단 제도 현황과 향후과제 (Status and Perspectives of Preplacement Health Examination (PHE) at Certain Workplaces)

  • 박혜숙;강성규;이완형;최원준;함승헌
    • 한국산업보건학회지
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    • 제31권4호
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    • pp.540-548
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    • 2021
  • Introduction: Preplacement health examination (PHE) is performed when a worker starts a certain work task which is designated as having occupational risks by the Ministry of Employment and Labor (MOEL). All data related to health examination except PHE are reported to the MOEL by the law. This study has been performed to understand the status of PHE at certain workplaces. Methods: PHE data gathered in a university hospital were analyzed and they were followed with results of the special health examination (SHE) in 2019 and 2020. Those who were evaluated as unfit to work as it was, were interviewed directly or indirectly through an occupational health manager to follow up the management status of their recognized health problems. Results: The unfit to work (unFTW) rate of PHE was 2.8%, and was not different according to the size of workplace or having occupational health service. The major cause of unfit to work was the uncontrolled life-style diseases such as hypertension and diabetes. The rate of SHE followed by PHE was 31.1%. It was not different by the unFTW rates, however, they were different according to having a full time in-house occupational health manager. Thirty-one among 71 examinees who were evaluated as unFTW underwent SHE after controlling their health condition and were finally evaluated as fit to work. Nineteen among 31 started to take medicine and eight have been placed in the work without designated risks. Conclusion: PHE can be used for new workers, who may have unknown or uncontrolled life-style diseases, to be asked to manage life-style diseases as well as work-related risks such as shift work. In order to have a better tracking system for work-related risks, the information of PHE should be analyzed together with other data from health examination.

소형 공정열교환기 시제품에 대한 탄소성 고온구조해석 (Elastic/Plastic High-temperature Structural Analysis on the Small Scale PHE Prototype)

  • 송기남;이형연;홍성덕;박홍윤
    • 한국압력기기공학회 논문집
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    • 제7권2호
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    • pp.1-6
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    • 2011
  • PHE(Process Heat Exchanger) is a key component required to transfer heat energy of $950^{\circ}C$ generated in a VHTR(Very High Temperature Reactor) to the chemical reaction that yields a large quantity of hydrogen. Korea Atomic Energy Research Institute established a small-scale gas loop for the performance test of components, which are used in the VHTR, and they manufactured a PHE prototype made of Hastelloy-X to be tested in the small-scale gas loop. Results from the elastic structural analysis on the PHE prototype were reported in the previous article. In order to investigate the macroscopic structural characteristics and behavior of the PHE prototype under the test condition of the small-scale gas loop far more in detail, elastic-plastic high-temperature structural-analysis of the PHE prototype was carried out in this study.

Effectiveness of Iliopsoas Self-Stretching on Hip Extension Angle, Gluteus Maximus Activity, and Pelvic Compensations during Prone Hip Extension in Subjects with Iliopsoas Shortness

  • Kim, Ki-Song;Jeon, In-Cheol
    • The Journal of Korean Physical Therapy
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    • 제30권1호
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    • pp.23-28
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    • 2018
  • Purpose: This study examined the effectiveness of iliopsoas self-stretching on the hip extension angle, gluteus maximus (GM) activity, and pelvic compensated angle during prone hip extension (PHE) in subjects with iliopsoas shortness. Methods: Twenty-healthy subjects with iliopsoas shortness were recruited. Electromyography (EMG) was used to examine erector spinae (ES), multifidus (MF), GM, and biceps femoris (BF) while performing PHE. An electromagnetic tracking motion analysis device was used to measure the pelvic compensations. The pelvic compensations while performing PHE were considered to be anterior tilting and rotation. A modified Thomas test was used to monitor the hip extension angle before and after iliopsoas self-stretching. A paired t-test was used to investigate the significant difference after iliopsoas self-stretching during PHE. The level of statistical significance was set to ${\alpha}=0.05$. Results: Muscle activity of GM and hip extension angle were significantly greater after iliopsoas self-stretching compared to that before iliopsoas self-stretching during PHE (p<0.05). BF and pelvic rotation angle were significantly lower after iliopsoas self-stretching compared to that before iliopsoas self-stretching during PHE (p<0.05). The muscle activity of ES was not significantly different between PHE before and after iliopsoas self-stretching (p>0.05). Conclusion: Iliopsoas self-stretching can be effective in selectively strengthening the GM muscles with minimized pelvic compensation in subjects with iliopsoas shortness.

새로운 반응기구에 의한 bradykinin 유사물의 합성 (Synethesis of bradykinin analogues by new reaction vessel)

  • 최청
    • Applied Biological Chemistry
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    • 제34권4호
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    • pp.334-338
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    • 1991
  • 고상법으로 새로운 반응기구에 의한 bradykinin 및 $(D-Phe7\;-Leu^8)$ bradykinin을 합성하였다. Coupling은 N, N'-dicyclohexylcarbodiimide로 행하였으며 HBr 용액으로 cleavage한 후 조펩티드는 high pressure liquid chromatography로 정제하였다. 이들 펩티드의 순도는 paper chromatography, thin layer chromatography, paper electrophoresis, 융점측정기 및 아미노산기분석기에 의하여 분석하였다. Endopeptidase인 ${\alpha}-chymotrypsin$과 trysin, exopeptidase인 carboxypeptidase A와 leucine aminopeptidase를 사용하여 in vitro 상에서 이들 펩티드의 분해실험을 하였다. ${\alpha}-Chymotrypsine$ 및 carboxypeptidase A에 의하여 이들 펩티드는 빠르게 분해하였으나 leucine aminopeptidase는 N-말단의 2번 위치에 proline의 imino결합 때문에 분해하지 않았다.

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