• 제목/요약/키워드: ST-N

검색결과 1,529건 처리시간 0.03초

연속반응기에서 Styrene과 n-Butylmethacrylate의 용액 공중합의 속도론 (The Kinetics of Solution Copolymerization of styrene and n-Butylmethacrylate in a Continuous Stirred Tank Reactor(CSTR))

  • 김남석;설수덕
    • 공업화학
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    • 제8권3호
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    • pp.347-356
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    • 1997
  • 스티렌(St)과 n-부틸메타크릴레이트(n-BMA)를 용매인 톨루엔에서 과산화벤조일(BPO)를 개시제로 사용하여 $80^{\circ}C$에서 연속반응기를 사용하여 용액공중합을 행하였다. 반응물 부피, 체류시간은 각각 0.6L, 3시간으로 하였다. 단량체 반응성비 $r_1$(St)과 $r_2$(BMA)는 Kelen-Tudos방법 (또는 Fineman-Ross방법)으로 결정하였다. : $r_1$=0.75(0.67), $r_2$=0.61(0.56). 공중합체의 가교정지인자, $\phi$값은 스티렌의 전체 조송에 대해 0.44~0.78값을 가지고 공중합체내 스티렌 조송이 증가할수록 $\phi$값도 증가하고 있다. 스티렌과 부틸메타크릴레이트의 공중합반응은 2차 반응속도식에 따랐으며 시뮬레이션한 전환율과 공중합 속도를 실험결과와 비교하였다. 동족인 정상상태에 도달하는 평균시간은 체류시간의 3.5배였다.

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The Potato Transcriptional Co-activator StMBF1 Is Up-regulated in Response to Oxidative Stress and Interacts with the TATA-box Binding Protein

  • Arce, Debora Pamela;Tonon, Claudia;Zanetti, Maria Eugenia;Godoy, Andrea Veronica;Hirose, Susumu;Casalongue, Claudia Anahi
    • BMB Reports
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    • 제39권4호
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    • pp.355-360
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    • 2006
  • To gain a better understanding on the function of the potato Solanum tuberosum Multiprotein Bridging Factor 1 protein (StMBF1) its interaction with the TATA box binding protein (TBP) was demonstrated. In addition we reported that StMBF1 rescues the yeast mbf1 mutant phenotype, indicating its role as a plant co-activator. These data reinforce the hypothesis that MBF1 function is also conserved among non closely related plant species. In addition, measurement of StMBF1 protein level by Western blot using anti-StMBF1 antibodies indicated that the protein level increased upon $H_2O_2$ and heat shock treatments. However, the potato $\beta$-1,3-glucanase protein level was not changed under the same experimental conditions. These data indicate that StMBF1 participates in the cell stress response against oxidative stress allowing us to suggest that MBF1 genes from different plant groups may share similar functions.

약물방출 관상동맥 스텐트 시술 후 스텐트 혈전증 발생 환자의 임상경과 (Clinical Outcomes of Stent Thrombosis after Drug-Eluting Coronary Stent Implantation)

  • 김인수;정명호;한재복;장영일;장성주
    • 한국콘텐츠학회논문지
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    • 제13권12호
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    • pp.880-892
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    • 2013
  • 약물방출 스텐트 (drug-eluting stents, DES)는 일반금속 스텐트에 비하여 재협착을 현저하게 줄었지만, DES의 구조적인 특성으로 인한 스텐트 혈전증 (stent thrombosis, ST)이 증가한다고 알려져 있다. 혈전증 유형의 정의는 Early ST ; (EST)은 30일 이내, Late ST ; (LST)은 31일 이상에서 1년 이내 그리고 Very late ST ; (VLST)은 1년 이상으로 분류 하였다. 스텐트 세대별 (시장 출시와 스텐트 디자인, Polymer 향상에 따른) ST발생빈도, 임상 양상 및 예후를 알아보았다. 2003년 6월부터 2013년 6월까지의 전남대학교병원 심혈관센터에서 경피적 관상동맥 중재술을 시행 받은 10,273명 중 ST 발생은 134명 (1.30%) 이었다. 세대별 발생빈도는 1세대에서 81명 (0.79%)으로 높았으며, 세대별 ST 유형은 1세대에서는 VLST의 발생률이 높았고 (p=0.002), 2세대에서는 EST와 LST의 발생률이 높았지만 (p=0.025), 3세대에서는 유의한 차이가 없었다(p=0.278). ST로 인하여 사망한 14명은 EST 10명 (18.2%), LST 2명 (8.3%), VLST 2명 (3.6%)로서 EST에서 사망률이 높았다 (p=0.042). DES 시술 후 발생하는 ST는 1.3% 이였고, VLST는 1세대 스텐트에서 많았으며, 입원 중 사망률은 EST에서 높았다.

Supplementation of Holstein Cows with Low Doses of Bovine Somatotropin (bST) Prepartum and Postpartum Affects Physiological Adaptations and Milk Production

  • Liboni, M.;Gulay, M.S.;Hayen, M.J.;Belloso, T.I.;Head, H.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권3호
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    • pp.404-413
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    • 2008
  • Major objectives were to evaluate effects of three schemes of bST-supplementation of Holstein cows (142.8 mg/14 d, POSILAC) during the prepartum and/or postpartum periods through 63 d (${\pm}3d$) of lactation. Measures evaluated the potential of treatments to improve body weight (BW) and body condition score (BCS), provoke changes in plasma concentrations of somatotropin (ST) and IGF-I, and improve milk yield, milk composition (percentages of protein and fat, and somatic cell counts), and several calving variables. Multiparous Holstein cows were randomly assigned to a $2{\times}2$ factorial arrangement of treatments (TRT) to give four groups (I = no bST, n = 26; II = bST postpartum, n = 25; III = bST prepartum, n = 27; IV = bST prepartum and postpartum, n = 25). During the prepartum period, cows in groups I and II were not supplemented but those in groups III and IV were supplemented every 2-wk beginning 21 d before expected calving date through calving. During the first 63 DIM only cows in groups II and IV were supplemented with bST. From 64 DIM through the end of lactation cows in all groups were supplemented with the full lactation dose of bST (500 mg/14 d). The BW and BCS were recorded weekly throughout the prepartum and postpartum periods and every 2-wk beyond 70 DIM. Blood samples were collected 3-times a week for analyses of ST and IGF-I. Milk yields were recorded daily though 150 DIM. Prepartum supplementation of bST did not affect BW or BCS, but mean concentrations of ST were increased 12.2% and were 15.5% greater at calving. Overall, mean concentration of IGF-I was not affected by treatment but concentrations were greater at 1 and 2 wk before calving in bST-supplemented cows. During the first 63 DIM the BW and BCS were not affected by treatment. Significant effects of bST-supplementation were detected on concentrations of ST, IGF-I and on milk yield compared to non-supplemented cows in group I. Postpartum concentrations of ST were greater in bST-supplemented cows (TRT II and IV; +41.9 and 54.6%). However, concentrations of IGF-I were greater only in cows in group IV (+25.9%) during the postpartum period. Overall, the three bST-supplemented groups had greater actual milk yield than the control group (I) during the first 63 and 150 DIM. The actual milk yields during 63 and 150 DIM were 6.5 and 4.6 kg/d greater for cows in group IV than cows in group I and the 305-d ME milk yield also was 15.6% greater. No adverse effects of TRT were observed on calf birth weight, colostrum immunoglobulins, ease of calving or other measures evaluated.

백서의 위와 족삼리에서 스트레스 관련(CRF, CRF-R, CRF-BP) 신경전달물질의 발현에 대한 연구 (Expression of neurotransmitter(CRF, CRF-R and CRF-BP) related to stress in stomach and zusanli in rats)

  • 이창현;김영호;송범용;육태한
    • Journal of Acupuncture Research
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    • 제20권6호
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    • pp.89-102
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    • 2003
  • Objective: The expression of CRF(corticotropin releasing factor), CRF-R(receptor) and CRF-BP(binding protein) in CNS neurons projecting to the stomach and ST36 using the pseudorabies virus in the rat was investigated. Methods: After survival times of 5 days following injection of PRV-Ba-Gal, The thirty rats were perfused, and their brain were frozen sectioned($30{\mu}m$). These sections were stained by PRV-Ba-Gal histochemical staining method and(or) CRF, CRF-R and CRF-BP immunohistochemical method. The common expressed areas of the brain projecting to the stomach and zusanli(ST36) following injection of PRV-Ba-Gal were observed with light microscope. Results: 1) The dense accumulation of CRF-immunoreactive terminals is seen in the area postrema, n. tractus solitarius, external zone of the median eminence, with some immunoreactive CRF also present in the internal zone. 2) Aggregates of CRF-R immunoreactive perikarya are found in area postrema, n. tractus solitarius, lateral reticular n., gigantocellular reticular n., locus coeruleues, paraventricular n. of hypothalamus, median eminence, preoptic n., arcuate n. and hind limb area of cerebral cortex. 3) Aggregates of CRF-BP immunoreactive perikarya are found in area postrema, n. tractus solitarius, lateral reticular nucleus, gigantocellular reticular n., locus coeruleues, paraventricular n. of hypothalamus, median eminence and arcuate n.. Conclusions : These results suggest that PRV-Ba-Gal labeled areas projecting to stomach and ST36 may be related to the central autonomic pathways. A part of CNS neurons projecting to the stomach and ST36 were related to expression of CRF, CRF-R and CRF-BP related to the stress in central autonomic center.

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뱀장어(Anguilla japonica)장의 상피세포막에 존재하는 새로운 clonidine 결합 수용체에 관한 연구 (A New Receptor for site Clonidine in the Eel, Anguilla japonica Intestine)

  • 김흥태;서정수;박남규;이형호;정준기
    • 한국어병학회지
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    • 제14권1호
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    • pp.31-36
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    • 2001
  • 해수에 적응된 뱀장어, Anguilla japonica의 장 세포막으로부터 새로운 clonidine의 결합부위가 있음이 밝혀졌다. Clonidine의 특이적인 결합부위는 적어도 2개의 부위 (high affinity $K_d=1.4{\pm}0.3$ nMn= 5, low affinity $K_d=175{\pm}34$ nM)를 가지고 있었다. 2nM [$^3H$]clonidine의 특이적인 결합은 $20^{\circ}C$, pH 7.5에서 최적 결합능을 가지고 있었고, 라벨되지 않은 clonidine에 의해 가역적인 반응을 보였다. 이러한 결합은 adrenaline, yohimbine과 rauwolscine에 의한 저해능은 약하였다. 그리고 대부분의 결합부위는 $\alpha_2$-adrenoceptor와는 상이하였다. Clonidine의 특이적인 결합은 다양한 imidazoline/guanidinium약물에 의해 억제되었다. Competition 실험의 결과, 2nM[$^3H$]clonidine의 치환 rank order는 다음과 같다. guanabenz > cirazoline = naphazoline=UK14,304= ST587 $\geq$ clonidine $\geq$ idazoxan = RX821002 = tolazoline > ST93 = oxymetazoline = amiloride = ST91 > yohimbine = efaroxan = rauwolscine $\geq$ adrenaline = ST567 = histamine = agmatine. 이러한 순서는 포유류에 분류된 imidazoline receptorl($I_1$), imidazoline receptor 2($I_2$) 및 imidazoline/guanidinium receptive sites(IGRS)형태와는 틀리기 때문에 새로운 imidazoline receptor라고 생각된다. 지금까지 보고된 포유류의 세포와 조직에서 IGRS의 생리학적인 역할은 명확하지 않지만, 해수뱀장어 장은 IGRS의 세포에 있어서의 역할 그리고 IGRS의 내인성(內因性) ligand가 무엇인가에 대한 좋은 모델이 될 수 있다고 생각되어진다.

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광조사 중합법에 의해 합성된 PP-g-AA와 PP-g-St 부직포의 암모니아성 질소 흡착특성 비교 (Ammonium Adsorption Property of Acrylic Acid and Styren Grafting Polypropylene Non-Woven Fabric Synthesized by Photo-induced Polymerization)

  • 박현주;나춘기
    • 한국환경과학회지
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    • 제17권11호
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    • pp.1255-1263
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    • 2008
  • The efficiency of PP-g-AA and PP-g-St nonwoven fabric synthesized by photoinduced polymerization as an adsorbent for removal $NH_3-N$ from waste water was evaluated. The results evidently indicate that the adsorption capacities of $NH_3-N$ onto PP-g-AA nonwoven fabric were extremely superior to those onto sulfonated PP-g-St nonwoven fabric, PK and zeolite. PP-g-AA nonwoven fabric showed the maximum adsorption capacity of $NH_3-N$ at the degree of grafting of 80 wt.%. The adsorption behaviour of $NH_3-N$ onto PP-g-AA and sulfonated PP-g-St nonwoven fabric was controlled by an ion exchange reaction, and tended to be similar to both trends of Langmiur and Freundlish isotherm. Futhermore, PP-g-AA non-woven fabric could be regenerated more than 5 times by a simple washing with 0.1N HCl with no decrease of adsorption capacity and no degradation of physical properties. Also sulfonated PP-g-St nonwoven fabric could be regenerated by washing with 0.1N ${H_2}{O_4}$. However, their regeneration efficiency was significantly low because grafting layer acted as functional radical for adsorption was continuously desquamated in the adsorption or regeneration processes, which resulted in decrease of adsorption capacity and weight of adsorbent. All results obtained from this study indicate that the $NH_3-N$ removal capacity of PP-g-AA non-woven fabric was extremely superior to those of PP-g-St non-woven fabric, PK and zeolite.

동해 울릉도-독도해역에서 질소, 인, 철 첨가실험에 따른 식물플랑크톤의 성장 및 군집반응 (Growth and community response of phytoplankton by N, P and Fe nutrient addition in around water of Ulleungdo and Dokdo in East Sea)

  • 백승호;이민지;김윤배
    • 한국산학기술학회논문지
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    • 제17권11호
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    • pp.186-195
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    • 2016
  • 동해 울릉도-독도 2정점에서 식물플랑크톤의 군집조성 및 수직적 영양염분포 특성과 표층 현장수를 이용하여 N, P, NP, Fe을 첨가하여 식물플랑크톤의 영양염소비 및 성장특성을 파악하였다. 현장에서 영양염류농도는 유광층 상부에서 낮았고, 100 m보다 깊은 수심에서 증가하였다. N:P비는 Redfield비(16)보다 표층에서 21-25로 높았고, 조사 최대심도인 400 m 층에서는 6 전후로 극히 낮게 관찰되었다. 식물플랑크톤의 총개체수는 St.UD3과 St.50에서 각각 $4.9{\times}10^5cells\;L^{-1}$$1.9{\times}10^5cells\;L^{-1}$로 관찰되었다. 주요 우점종은 St.UD3에서 침편모조류 Heterosigma akashiwo, 은편모조류 Crytomonas spp., 규조류 Leptocylindrus danicus로 파악되었고, St.50에서는 규조류 Chaetoceros socialis, H. akashiwo, L. danicus로 각각 관찰되었다. 영양염첨가실험의 +N과 +NP실험군에서 빠른 식물플랑크톤의 성장반응을 보였고, +P실험군에서는 대조군과 유사하게 식물플랑크톤 성장이 관찰되지 않았다. 아울러 Fe을 첨가한 대조군, +N, +P, +NP실험군에서 Fe을 첨가하지 않은 다른 실험군과 비교하여 형광값의 유의한 차이를 보이지 않았다는 것은 Fe첨가에 따른 식물플랑크톤의 성장반응이 명확하지 않다는 것을 의미한다(p>0.05). 결과적으로 현장에서 우점한 H. akashiwo 와 L. danicus는 영양염이 추가적으로 공급된 환경의 생물검증실험에서도 빠르게 반응하여 높은 개체수로 우점한 것을 파악하였고, 특히 +Fe 실험군에서 L. danicus의 빠른 성장이 두드려졌다.

송아지 난소에서 초음파 유도에 의한 한우의 미성숙난자 채취시에 bST-FSH 처리효과에 관한 연구 (Effect of bST Co-Treatment with FSH on Transvaginal Ultrasound-Guided Oocyte Retrieval(TVR) in Calves)

  • 이병천;이강남;김남렬;황우석
    • 한국수정란이식학회지
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    • 제11권2호
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    • pp.103-109
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    • 1996
  • The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle ($\geq$5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.

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Comparison of conventional and new endoscopic band ligation devices for colonic diverticular bleeding

  • Ayaka Takasu;Takashi Ikeya;Yasutoshi Shiratori
    • Clinical Endoscopy
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    • 제55권3호
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    • pp.408-416
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    • 2022
  • Background/Aims: Endoscopic band ligation (EBL) is used to treat colonic diverticular bleeding (CDB). An endoscopic variceal ligation device for esophageal varices is used as a conventional EBL device (C-EBL). A new EBL device (N-EBL) was developed by Sumitomo Bakelite Co. in August 2018. We aimed to evaluate the clinical outcomes of N-EBL compared with those of C-EBL. Methods: Seventy-nine patients who underwent EBL for CDB at St. Luke's International Hospital, Japan, between 2017 and 2020 were included in this retrospective study. Patients were divided into the C-EBL and N-EBL groups. Their clinical outcomes, including achieving initial hemostasis, early rebleeding, procedure time, and EBL-associated adverse events, were evaluated. Results: Of the 79 patients, 36 (45.6%) were in the C-EBL group and 43 (54.4%) were in the N-EBL group. The rate of achieving initial hemostasis was 100% in the C-EBL group and 93.0% in the N-EBL group. No significant difference was noted in the early rebleeding rate between the groups (p=0.24). The N-EBL group achieved a shorter median EBL procedure time than the C-EBL group (14.2 minutes vs. 18.2 minutes, p=0.02). No adverse events were observed in either group. Conclusions: The N-EBL device is safe and useful and may reduce EBL procedure time.