• 제목/요약/키워드: AtRA

검색결과 2,429건 처리시간 0.027초

Subacute Toxicities of All-trans-Retinoic Acid Encapsulated in the Poly(D,L-Lactide) Microspheres

  • 최용두;박경순;김상윤;김선희;변영로
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.867-870
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    • 2001
  • 아급성 독성 시험으로부터, 미립구내의 레티노익 산을 기준으로 한 투여량이 100mg/kg 일때는 4마리의 치사 개체가 보이는 등의 심각한 독성 효과가 유발되었으며, 25 및 50mg/kg인 경우에 독성 효과가 거의 나타나지 않음을 관찰하였다. 50mg/kg의 투여량의 경우, 일부 동물에서 뼈골절 현상이 나타났지만, 이러한 독성효과는 항염증제를 같이 투여함으로써 극복될 수 있을 것으로 생각되어졌다. 따라서, 앞으로의 실험에서는 항염증제를 이용하여, 가능한 독성을 억제하연서, 보다 빠른 기간 내에 상태가 회복될 수 있도록 하는 연구를 행할 것이다.

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LoRa 센서네트워크 기반의 무선교량유지관리 시스템 구축 (Bridge Monitoring System based on LoRa Sensor Network)

  • 박진오;박상헌;김경수;박원주;김종훈
    • 한국전산구조공학회논문집
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    • 제33권2호
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    • pp.113-119
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    • 2020
  • 사물인터넷 기반의 센서네트워크는 저렴한 비용으로 효율적으로 교량 등의 시설물 유지관리에 적용할 수 있는 한 방안이다. 본 연구에서는 사물인터넷 통신의 하나인, LoRa LPWAN 기반으로 교량 구조건전성모니터링을 위한 시스템을 개발하기 위해서 케이블 장력 모니터링을 위한 센서보드, 기존 계측 센서들과 함께 센서네트워크를 구축하기 위한 DAQ 보드, 데이터들 처리하고 LoRa 통신을 위한 스마트센서노드를 설계 및 제작하였으며 모니터링을 위한 센서네트워크를 구축하였다. 또한 본 시스템의 성능검증을 위해 영광대교에 Test Bed를 구축하여 교량 구조건전성 모니터링을 위한 센서네트워크에 적용가능성 여부를 살펴보았다. Test Bed 검증 결과 LoRa LPWAN 기반 센서네트워크는 데이터 전송률, 정확도, 경제성면에서 교량 구조 건전성 모니터링의 기술 중에 하나로 적용될 수 있으며, 향후 교량구조물 뿐만 아니라 다양한 공공기반 시설물에 유지관리를 위한 시스템으로 보급될 수 있기를 기대한다.

LDPC 부호와 RA 부호의 최소 거리 검색 알고리즘 (Minimum Distance Search Algorithms of LDPC Codes and RA Codes)

  • 정규혁
    • 한국통신학회논문지
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    • 제31권3A호
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    • pp.207-213
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    • 2006
  • 본 논문은 반복 부분을 이용하여 단지 유효한 부호어만을 검색함으로서 RA 부호의 최소 거리를 구하기 위한 계산량을 줄인다. LDPC 부호도 RA 부호와 같이 반복 부분을 가지므로 제안된 알고리즘은 LDPC 부호의 최소거리 계산에도 적응된다. 최소 거리는 높은 신호대 잡음비에서 부호의 성능을 결정한다. 따라서 오류 마루를 추정하는 것을 가능하게 한다. 제안된 알고리즘은 부호 구조에 어떠한 제한도 두지 않고 최소 거리를 구할 수 있다. 실제적 의미가 있는 큰 길이의 인터리버를 가진 LDPC 부호와 RA 부호의 최소 거리가 본 논문에서 구해지며 이에 따른 오류 마루를 구하며 또한 이 오류 마루는 반복 복호의 성능과 비교된다.

Effects of Shoulder Abduction in Opposite Directions on EMG Activity in the Abdominal Muscles during Single Leg Raising in the Supine Position on the Foam Roller in Healthy Subjects

  • Yun, Sung-Joon;Kim, Moon-Hwan
    • The Journal of Korean Physical Therapy
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    • 제27권4호
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    • pp.270-274
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    • 2015
  • Purpose: The purpose of this study was to examine the electromyographic (EMG) activity of the abdominal muscles and to compare the activity ratios of the bilateral rectus abdominis (RA) to oblique abdominal muscles during shoulder abduction in opposite directions with single leg raising (SLR) performed in the supine position on a foam roller. Methods: Fifteen healthy subjects were recruited to the study. Each subject lay on the foam roller and performed left single leg raising with right or left shoulder $90^{\circ}$ abduction (Abd); performed in a random order. Surface EMG recordings of selected abdominal muscles (i.e., the RA, external oblique abdominis [EO], internal oblique abdominis [IO], and transverse abdominis [TrA]) were normalized to maximum voluntary isometric contraction. EO/RA and IO and TrA/RA ratios were determined with surface EMG. Data were analyzed by Independent t-test. The statistical significance level was p<0.05. Results: The results were as follows: (1) the right RA, left EO, and right IO and TrA muscle activities increased significantly at the left SLR with left Abd compared to the left SLR with right Abd (p<0.05); and (2) the ratio of right EO/RA activity increased significantly at the left SLR with right Abd compared to left Abd (p<0.05). Conclusion: These findings suggest that left SLR with left Abd on a foam roller is an appropriate exercise for activation of specific oblique abdominal muscles.

콩 불마름병균의 생장 조건이 박테리오신인 glycinecin의 생성에 미치는 영향 (Influence of Growth Conditions for the Production of Bacteriocin, Glycinecin, Produced by Xanthmonas campestris pv. glycines 8ra)

  • Woo Jung;Sunggi Heu;Cho, Yong-Sup
    • 한국식물병리학회지
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    • 제14권5호
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    • pp.376-381
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    • 1998
  • Xanthomonas campestris pv. glycines 8ra causes bacterial pustule disease on susceptible soybean leaves and produces a bacteriocin, named glycinecin, against related bacteria such as Xanthomonas campestris pv. vesicatoria. The antimicrobial activity of the glycinecin was effective to most tested Xanthomonas species. X. c. pv. glycines 8ra was able to produce the glycinecin in liquid media as well as solid media. Maximal productivity of glycinecin was obtained at 3$0^{\circ}C$ in the early stationary phase of growth of the X. c. pv. glycines 8ra. The production of glycinecin was not dependent on the initial inoculum level but on cell density. Glycinecin was very sensitive to proteolytic enzymes such as trypsin and proteinase K but resistant to DNase and RNase. The culture supernatant of X. c. pv. glycines 8ra retained some of its antimicrobial activity after 15 min at 6$0^{\circ}C$. It is stable at wide range of pH. The glycinecin showed the bactericidal activity after the adsorption of the glycinecin to the sensitive bacterial cell.

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한국 동해 표층수중 $^{226}Ra$$^{228}Ra$의 농도분포 (Distributions of $^{226}Ra$\;and\;^{228}Ra$in the Surface Waters of East Sea of Korea)

  • 양한섭;권영안;김규범;김성수
    • 한국수산과학회지
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    • 제25권5호
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    • pp.399-405
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    • 1992
  • 동해 남부 및 중부해역의 총 14개 정점에서 표층수중 Ra동위체를 $MnO_2$피복 아크릴섬유로 추출한 후 분리농축시켜 감마계측하였다. 본 연구결과, 동해표층수중 $^{228}Ra$의 농도분포는 102-232 $dpm/10^3l$ 범위로 연안정점들이 외해역 정점보다 다소 높은 농도를 보였고, 대마난류의 주류가 북상하는 정점들에서 상대적으로 높은 농도를 보였다. $^{226}Ra$의 농도는 70-110 $dpm/10^3l$ 범위로 $^{228}Ra$에 비해 해역별 혹은 정점별로 농도차이가 작았으나, 농도분포는 $^{228}Ra$의 경우와 유사하였다. 동해표층수중 Ra동위체의 비는 1.0-2.7 범위로 쿠로시오 표층수 보다 훨씬 큰 값이나, 황해표층수 보다는 작은 값이다. 동해표층수중 해역별 Ra동위체비의 수평분포는 $^{228}Ra$의 농도분포와 비슷하다. 동해표층수중 $^{226}Ra$$^{228}Ra$은 좋은 정의 상관성을 나타내며, 염분에 대한 $^{228}Ra$의 농도도 좋은 역의 상관성을 나타내었다. 염분과 Ra동위체비의 상관관계로부터 동해표층수는 황해 및 동지나해 대륙붕수와 쿠로시오 표층수가 혼합된 것으로 사료되며, 동해표충수중 Ra동위체의 농도는 해역별 혹은 계절별로 달라진다.

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The Fermentation Characteristics of Newly Selected Thermotolerant Yeasts at High Temperature

  • Sohn, Ho-Yong;Park, Wan;Jin, Ing-Nyol;Seu, Jung-Hwn
    • Journal of Microbiology and Biotechnology
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    • 제4권3호
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    • pp.222-229
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    • 1994
  • In order to develop a method of economical production and to reduce energy-consumption in fuel alcohol production, we investigated the fermentation characters of two newly selected thermotolerant yeasts. The RA-74-2 showed stable and superior fermentability between 30 and $40^{\circ}C$ in 20% glucose media in comparison to the industrial strains. The optimum concentration of glucose for economical fermentation at $40^{\circ}C$ was 15-18%, and organic nitrogen was necessary for a satisfactory fermentation. The optimum pH was 4.0 and aeration was adversed for high temperature fermentation. Agitation was an important factor at $40^{\circ}C$ and the addition of magnesium ion 0.2% was required in this experiment. When the inoculum was increased, ethanol productivity as well as the speed of fermentation increased. On the other hand RA-912, which can grow at $48^{\circ}C$, showed similar fermentability between 30-$45^{\circ}C$ in 20% glucose media As the concentration of substrate decreased, fermentation ratio increased at $45^{\circ}C$ (45%, 65%, 95% fermentation ratio in 20%, 15%, 10% glucose media, respectively). Also, requirement of organic nitrogen and magnesium ion in RA-912 was similar in RA-74-2. The optimum pH for fermentation was 5.0, and the effects of agitation were enhanced at $37^{\circ}C$ than at $45^{\circ}C$. As the inoculum was increased, fermentation speed became more enhanced but the ethanol productivity was less affected. RA-912 showed fermentability with various substrates. Among the substrates used, inulin was the most promising substrate for the high-temperature fermentation. When 14.5% inulin was used as the substrate, 93% and 55% fermentation ratios were shown at $37^{\circ}C$ and $45^{\circ}C$, respectively.

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Application of Thermotolerant Yeast at High Temperature in Jar-fermentor Scale.

  • Sohn, Ho-Yong;Kim, Young-Ho;Rhee, In-Koo
    • Journal of Microbiology and Biotechnology
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    • 제4권4호
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    • pp.316-321
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    • 1994
  • We investigated the possibility of industrial application and economit process of high temperature fermentation by thermotolerant alcohol producing yeasts as previously reported. From the 20% glucose media, the RA-74-2 produced 11.8% (v/v) ethanol at $32^{\circ}C$ (0.5% inoculum) and 10.6% (v/v) ethanol at $40^{\circ}C$ (3% inoculum), respectively. Also, 11.3% (v/v) ethanol was produced for 96 hours in the temperature-gradient fermentation. These results suggest that the RA-74-2 could isuccessfully be applied to save the cooling water and energy in industrial scale without re-investment or modification of established fermentation systems. When potato starch was used as the substrate for the RA-74-2, high temperature fermentation above $40^{\circ}C$ was more appropriate for industrial utilization because organic nitrogen was not necessary to economical fermentation. As the naked barley media just prior to industrial inoculation, taken from the Poongkuk alcohol industry Co., were used, 9.6% (v/v) ethanol was produced at $40^{\circ}C$ for 48 hours in jar-fermentor scale (actually, 9.5-9.8% (v/v) ethanol was produced at 30~$32^{\circ}C$ for 100 hours in industrial scale). The ethanol productivity was increased by the high glucoamylase activity as well as the high metabolic ratio at $40^{\circ}C$ Therefore, if the thermotolerant yeast RA-74-2 would be used in industrial scale, we could obtain a high productivity and saving of the cooling water and energy. Meanwhile, the RA-912 produced 6%(v/v) ethanol in 10% glucose media at $45^{\circ}C$ and showed the less ethanol-tolerance compared with industrial strains. As the produced alcohol was recovered by the vacuum evaporator at $45^{\circ}C$ in 15% glucose media, the final fermentation ratio was enhanced (76% of theoretical yields). This suggest that a hyperproductive process could be achieved by a continuous input of the substrate and continuous recovery of the product under vacuum in high cell-density culture.

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Reperfusion Arrhythmia에 관한 연구 III. 관상동맥 폐색시의 혈액동력학적인 변화와 RA발생과의 관계 (A Study on Reperfusion Arrhythmia III. Relationship to Hemodynamics Changes and Occurrence of Reperfusion Arrhythmia after Occlusion of Coronary Artery in Dogs)

  • 최인혁;정인성;최은경;김희은
    • 한국임상수의학회지
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    • 제18권4호
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    • pp.402-410
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    • 2001
  • This study was performed to investigate the hemodynamic changes which occur after occlusion of coronary artery and relation to reperfusion arrhythmias(RA) which occur when occlusion materials were removed form coronary artery in dogs. The occlusion of coronary artery was designed by temporary ligation of left circumflex branch of coronary artery during 30 minutes in 16 dogs. During occlusion of coronary artery, cardiac output(CO), mean aortic pressure (mAP), aortic systolic pressure(ASP), aortic diastolic pressure(ADP). left ventricular systolic pressure(LVSP), left ventricular maximum dp/dt (LV max. dp/dt) and left ventricular end-diastolic pressure (LVEDP) were measured. The occurrence of RA were observed for 5 minute after reperfusion by explained of ligation. As a results, cardiac arrest occurred in 4 dogs during occlusion of coronary artery, and RA was not observed in 5 dogs while it was seen in 5 dogs when explained ligation(reperfusion) after 30 minutes, the rest 2 dogs occurred temporary tachycardia. In hemodynamics changes, LVSP decreased by 10.9% and LV max. dp/dt by 5.4 % in comparison to control value which not ligated coronary artery, and LVEDP increased by 73.3%. The CO/min and mAP also decreased by 10.7% and by 11.3% expectedly. In the relationship to occurrence RA and hemodynamics changes, the LVSP and LV max. dp/dt at the time of occlusion in the RA group decreased by 11.9% and 0.8% in comarison to the control value while the decrease was 7.7% and 10% in the non-RA group. But the LVEDP in creased by 109.1% in the RA group while the decreased was 44.6% in the non-RA group. Referring CO/min, the drop was 8.8% in the RA occurrence group and 12.9% in the non-occurence group. These parameters of LVEDP, LV max. dp/dt, and CO were significant difference(p<0.05). The mAP also decreased by 11.9 in the RA group and by 9.8% in the non-RA group, but these defference were not the significant difference.

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Combined Treatment With TGF-β1, Retinoic Acid, and Lactoferrin Robustly Generate Inducible Tregs (iTregs) Against High Affinity Ligand

  • Young-Saeng Jang;Sun-Hee Park;Seung-Goo Kang;Jung-Shin Lee;Hyun-Jeong Ko;Pyeung-Hyeun Kim
    • IMMUNE NETWORK
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    • 제23권5호
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    • pp.37.1-37.11
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    • 2023
  • Forkhead box P3-positive (Foxp3+)-inducible Tregs (iTregs) are readily generated by TGF-β1 at low TCR signaling intensity. TGF-β1-mediated Foxp3 expression is further enhanced by retinoic acid (RA) and lactoferrin (LF). However, the intensity of TCR signaling required for induction of Foxp3 expression by TGF-β1 in combination with RA and LF is unknown. Here, we found that either RA or LF alone decreased TGF-β1-mediated Foxp3 expression at low TCR signaling intensity. In contrast, at high TCR signaling intensity, the addition of either RA or LF strongly increased TGF-β1-mediated Foxp3 expression. Moreover, decreased CD28 stimulation was more favorable for TGF-β1/LF-mediated Foxp3 expression. Lastly, we found that at high signaling intensities of both TCR and CD28, combined treatment with TGF-β1, RA, and LF induced robust expression of Foxp3, in parallel with powerful suppressive activity against responder T cell proliferation. Our findings that TGFβ/RA/LF strongly generate high affinity Ag-specific iTreg population would be useful for the control of unwanted hypersensitive immune reactions such as various autoimmune diseases.