• 제목/요약/키워드: blocking effect

검색결과 904건 처리시간 0.03초

A Portulaca oleracea L. extract promotes insulin secretion via a K+ATP channel dependent pathway in INS-1 pancreatic β-cells

  • Park, Jae Eun;Han, Ji Sook
    • Nutrition Research and Practice
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    • 제12권3호
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    • pp.183-190
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    • 2018
  • BACKGROUND/OBJECTIVE: This study was designed to investigate how a Portulaca oleracea L. extract (POE) stimulates insulin secretion in INS-1 pancreatic ${\beta}-cells$. MATERIALS/METHOD: INS-1 pancreatic ${\beta}-cells$ were incubated in the presence of various glucose concentrations: 1.1 or 5.6, 16.7 mM glucose. The cells were treated with insulin secretagogues or insulin secretion inhibitor for insulin secretion assay using an insulin ELISA kit. In order to quantify intracellular influx of $Ca^{2+}$ caused by POE treatment, the effect of POE on intracellular $Ca^{2+}$ in INS-1 pancreatic ${\beta}-cells$ was examined using Fluo-2 AM dye. RESULTS: POE at 10 to $200{\mu}g/mL$ significantly increased insulin secretion dose-dependently as compared to the control. Experiments at three glucose concentrations (1.1, 5.6, and 16.7 mM) confirmed that POE significantly stimulated insulin secretion on its own as well as in a glucose-dependent manner. POE also exerted synergistic effects on insulin secretion with secretagogues, such as L-alanine, 3-isobutyl-1-methylxanthine, and especially tolbutamide, and at a depolarizing concentration of KCl. The insulin secretion caused by POE was significantly attenuated by treatment with diazoxide, an opener of the $K{^+}_{ATP}$ channel (blocking insulin secretion) and by verapamil (a $Ca^{2+}$ channel blocker). The insulinotropic effect of POE was not observed under $Ca^{2+}$-free conditions in INS-1 pancreatic ${\beta}-cells$. When the cells were preincubated with a $Ca^{2+}$ fluorescent dye, Fluo-2 (acetoxymethyl ester), the cells treated with POE showed changes in fluorescence in red, green, and blue tones, indicating a significant increase in intracellular $Ca^{2+}$, which closely correlated with increases in the levels of insulin secretion. CONCLUSIONS: These findings indicate that POE stimulates insulin secretion via a $K{^+}_{ATP}$ channel-dependent pathway in INS-1 pancreatic ${\beta}-cells$.

SANOS 메모리 셀 트랜지스터에서 Tunnel Oxide-Si Substrate 계면 트랩에 따른 소자의 전기적 특성 및 신뢰성 분석 (Analysis of the Interface Trap Effect on Electrical Characteristic and Reliability of SANOS Memory Cell Transistor)

  • 박성수;최원호;한인식;나민기;엄재철;이승석;배기현;이희덕;이가원
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.94-95
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    • 2007
  • In this paper, the dependence of electrical characteristics of Silicon-$Al_2O_3$-Nitride-Oxide-Silicon (SANOS) memory cell transistors and program speed, reliability of memory device on interface trap between Si substrate and tunneling oxide was investigated. The devices were fabricated by the identical processing in a single lot except the deposition method of the charge trapping layer, nitride. In the case of P/E speed, it was shown that P/E speed is slower in the SONOS cell transistors with larger interface trap density by charge blocking effect, which is confirmed by simulation results. However, the data retention characteristics show much less dependence on interface trap. Therefore, to improve SANOS memory characteristic, it is very important to optimize the interface trap and charge trapping layer.

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Electrochromic 막의 특성과 물질이동 방지막의 효과에 대한 연구 (Studies on the properties of electrochromic films and the effect of migration barrier)

  • 황하룡;백지흠;허증수;이덕동;임정옥;장동식
    • 한국진공학회지
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    • 제9권3호
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    • pp.221-226
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    • 2000
  • 졸겔법 및 진공증착법으로 $WO_3$$V_2O_5$ 박막을 제조하고, 리튬이온을 이용하여 전기변색 소자를 제작한 후 광학적 특성을 조사하였다. 측정결과 졸겔법으로 제조된 $WO_3$ 박막과 $V_2O_5$ 박막을 수증기 분위기에서 $500^{\circ}C$로 1시간 열처리한 경우 가장 우수한 투과율 변화량을 나타내었다. 정.역방향 동작을 거듭할수록 $WO_3$막의 텅스텐과 ITO막의 인듐이 상호 확산하는 것을 관찰할 수 있었으며 이를 방지하기 위해 수백 $\AA$의 텅스텐 박막을 ITO와 $WO_3$막 사이에 삽입한 결과, cyclic voltamogram의 peak의 감소량이 1/10 이하로 감소하였으며, 리튬이온의 흐름에 의한 인듐과 텅스텐의 이동을 효과적으로 방지할 수 있었다.

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XO/HX에 의해 손상된 배양 심근세포에 대한 지실해백계지탕과 구성약물 추출물의 방어효과 (Protective Effects of Jisilhaebaekgyeji-tang and Constituents Extract on Cultured Rat Myocardial Cell treated by XO/HX)

  • 장승호;권강범;김인수;강길성;김인규;김인섭;류도곤
    • 동의생리병리학회지
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    • 제17권4호
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    • pp.952-957
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    • 2003
  • To certify the protective effect of herbal medicine against oxygen free radical-induced myocardiotoxicity, cytotoxicity was measured using LDH activity and TBARS assay in the presence of Jisilhaebaekgyejitang(JHGT) extracts or single constituents of this prescription, In the present study, xanthine oxidase/hypoxanthine (XO/HX) resulted in a cell damage such as increases in LDH activity in culture medium and lipid peroxidation in cultured myocardial cells. In the effect of JHGT extract and its single constituents, which are Fructus Ponciri Seu Aurantii Immaturus (FPSAI), Cortex Magnoliae Officinalis (CMO), Bulbus Allii Macrostemi (BAM), Ramulus Cinnamomi (RC) and Fructus Trichosanthis (FT), they showed the prevention from the XO/HX-induced cardiotoxicity by the decrease of LDH activity and lipid peroxidation. From these results, they show that XO/HX is cardiotoxic in cultured myocardial cells derived from neonatal rat, and it suggests that JHGT, FPSAI, PT, CMO, BAM, RC and FT extracts are positively effective in the blocking in XO/HX-induced cardiotoxicity.

C2C12 근육아세포에서 trichostatin A에 의한 NF-κB DNA 결합 활성과 근육발생에 미치는 영향 (Effect of trichostatin A on NF-κB DNA binding activity and myogenesis in C2Cl2 skeletal muscle Precursor cell)

  • 임운기;김경창;신혜자
    • 생명과학회지
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    • 제12권1호
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    • pp.55-60
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    • 2002
  • 골격근 세포의 분화는 근육특이 유전자들의 전사적 활성과 근육아세포에서 근육소관으로의 형태적 분화로 특징지어진다. 본 연구에서는 TSA가 근육형성의 일련의 과정에서 NF-kB DNA 결합 활성과 융합에 미치는 영향을 조사하였다. 대조군과 비교해서 TSA가 처리된 C2C12 myoblast는 융합하여 근육소관을 형성할 수 없었으며 NF-kB DNA 결합 활성은 억제되었다. 이런 현상들이 TSA에 의한 직접적인 것인지 알아보기 위해서 TSA가 처리되지 않고 분화를 유도하기 위해서 사용된 배지를 농축하여 C2C12 myoblast에 TSA와 함께 동시에 처리하였다. 그 결과 세포는 융합하여 근육소관을 형성하였으며 NF-kB DNA 결합 활성이 회복되었다. 이러한 결과는 TSA가 아마도 여러 관련 인자들을 통해 myoblast의 융합과 NF-kB DNA 결합 활성을 억제함으로 근육형성과정에 영향을 미침을 시사한다.

Anti-inflammatory Effect of Heracleum moellendorffii Roots through the Inhibition of NF-κB and MAPK Signaling, and Activation of ROS/Nrf2/HO-1 Signaling in LPS-stimulated RAW264.7 Cells

  • Park, Su Bin;Kim, Ha Na;Kim, Jeong Dong;Jeong, Jin Boo
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 추계학술대회
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    • pp.66-66
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    • 2019
  • Heracleum moellendorffii roots (HM-R) have been long treated for inflammatory diseases such as arthritis, backache and fever. However, an anti-inflammatory effect and the specific mechanism of HM-R were not yet clear. In this study, we for the first time explored the anti-inflammatory of HM-R. Results: HM-R dose-dependently blocked LPS-induced NO and PGE2 production. In addition, HM-R inhibited LPS-induced overexpression of iNOS, COX-2, $IL-1{\beta}$ and IL-6 in RAW264.7 cells. HM-R inhibited LPS-induced $NF-{\kappa}B$ signaling activation through blocking $I{\kappa}B-{\alpha}$ degradation and p65 nuclear accumulation. Furthermore, HM-R inhibited MAPK signaling activation by attenuating the phosphorylation of ERK1/2, p38 and JNK. HM-R increased nuclear accumulation of Nrf2 and HO-1 expression. However, NAC reduced the increased nuclear accumulation of Nrf2 and HO-1 expression by HM-R. In HPLC analysis, falcarinol was detected from HM-R as an anti-inflammatory compound. These results indicate that HM-R may exert anti-inflammatory activity by inhibiting $NF-{\kappa}B$ and MAPK signaling, and activating ROS/Nrf2/HO-1 signaling. From these findings, HM-R may have potential to be a candidate for the development of anti-inflammatory drugs.

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재난문자의 문제적 빈도 유형이 조절기대에 미치는 영향 (Effect of Problematic Frequency Types of the Korean Public Alert Service (KPAS) on Adjustment Expectation)

  • 이현지;변윤관;장석진;최성종
    • 방송공학회논문지
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    • 제26권6호
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    • pp.799-808
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    • 2021
  • 재난문자의 빈도가 재난문자의 차단 행위를 유발시키고 있다. 이 행위를 방지하기 위해서는 재난문자의 빈도를 조절할 필요가 있다. 본 연구는 재난문자의 문제적 빈도 유형이 재난문자 조절기대에 미치는 영향에 대해 분석하였다. 문제적 빈도 유형으로 일상성 빈도, 타 지역 빈도, 유사성 빈도를 선정하였다. 리서치 회사를 통해 총 1,212명을 대상으로 온라인 설문조사를 시행하였다. 연구 결과, 재난문자 조절기대에 일상성 빈도, 타 지역 빈도, 유사성 빈도가 정적으로 영향을 미치는 것으로 나타났다. 개별변인의 고유기여도는 유사성 빈도, 타 지역 빈도, 일상성 빈도 순 으로 나타났다. 이러한 연구 결과는 재난문자의 빈도를 개선하는 기본 자료로 활용될 수 있다는 점에서 의의가 있다.

Evaluation of effect over time after oral administration of telmisartan for chronic kidney disease in cats

  • Han, Donghyun;Lee, Dong-Guk;Jung, Dong-In
    • Journal of Biomedical and Translational Research
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    • 제19권4호
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    • pp.86-91
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    • 2018
  • Angiotensin receptor blockers, such as telmisartan, are considered effective in the treatment of hypertension and proteinuria due to chronic kidney disease (CKD) in cats. It selectively blocks the $AT_1$ receptor and does not affect the $AT_2$ receptor, thus effectively blocking the activity of the renin angiotensin aldosterone system. This study aims to compare over time the changes in various indicators, including systemic hypertension and proteinuria, before and after the administration of telmisartan in cats with CKD. Decrease in blood pressure (BP) (p<0.001) and urine protein to creatinine (UP/C) ratio (p<0.001) were found to be statistically significant over time after the administration of telmisartan. BP and the UP/C ratio were $160{\pm} 22.2$ and $0.50{\pm}0.647$ before telmisartan administration (Day 0), $150{\pm}21.0$ and $0.27{\pm}0.487$ on the 30th day (Day 30), $150{\pm}17.0$ and $0.25{\pm}0.376$ on the 60th day (Day 60), and $140{\pm}17.8$ and $0.15{\pm}0.233$ on the 90th day (Day 90) after administration, respectively. BP and UP/C were statistically significantly lower in cats with CKD over time at each time point from Day 0 to Day 90 at 30 day intervals. Especially after 90 days of telmisartan administration, the improvement of BP and UP/C were estimated to be about 20 mmHg and 0.35, respectively. In conclusion, the oral administration of telmisartan to cats with CKD is effective in improving BP and proteinuria, which has a positive effect on long-term survival in cats with CKD.

초음파 기반 혈뇌장벽 개방에 관한 최신 임상시험 연구 현황 (Recent clinical trials with ultrasound induced blood-brain barrier opening)

  • 박주영
    • 한국음향학회지
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    • 제41권5호
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    • pp.564-569
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    • 2022
  • 인체의 다른 장기들과 달리, 뇌는 혈뇌장벽(Blood-Brain Barrier, BBB)라는 보호 장치가 존재하여 뇌혈관내 물질들이 뇌조직으로 투과되는 것을 제한하는 역할을 한다. 이러한 BBB는 알츠하이머, 뇌종양 등 다양한 뇌질환에 직접적으로 전달이 필요한 약물의 투과까지 제한하기 때문에 치료 효능 검증 및 임상 적용이 어려운 것으로 보고되고 있다. 이러한 문제를 극복하기 위해 비침습적 특성의 집속 초음파(Focused Ultrasound, FUS)를 뇌의 국소 부위에 조사할 경우 마이크로버블의 음향공동화 현상으로 인해 BBB가 일시적으로 개방될 수 있는 기술이 개발되었으며, 해당 기술을 안전성 및 유효성 검증, 약물 전달 효율을 증대시킬 수 있는 다양한 연구가 전 세계적으로 수행되고 있다. 따라서, 본 논문에서는 알츠하이머, 뇌종양 등 뇌질환 치료를 위해 활발히 연구가 진행중인 집속초음파 기반 BBB 개방 기술에 대한 연구 동향을 분석하였다.

The effects of limestone powder and fly ash as an addition on fresh, elastic, inelastic and strength properties of self-compacting concrete

  • Hilmioglu, Hayati;Sengul, Cengiz;Ozkul, M. Hulusi
    • Advances in concrete construction
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    • 제14권2호
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    • pp.93-102
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    • 2022
  • In this study, limestone powder (LS) and fly ash (FA) were used as powder materials in self-compacting concrete (SCC) in increasing quantities in addition to cement, so that the two powders commonly used in the production of SCC could be compared in the same study. Considering the reduction of the maximum aggregate size in SCC, 10 mm or 16 mm was selected as the coarse aggregate size. The properties of fresh concrete were determined by slump flow (including T500 time), V-funnel and J-ring experiments. The experimental results showed that as the amount of both LS and FA increased, the slump flow also increased. The increase in powder material had a negative effect on V-funnel flow times, causing it to increase; however, the increase in FA concretes was smaller compared to LS ones. The increase in the powder content reduced the amount of blockage in the J-ring test for both aggregate sizes. As the hardened concrete properties, the compressive and splitting strengths as well as the modulus of elasticity were determined. Longitudinal and transverse deformations were measured by attaching a special frame to the cylindrical specimens and the values of Poisson's ratio, initiation and critical stresses were obtained. Despite having a similar W/C ratio, all SCC exhibited higher compressive strength than NVC. Compressive strength increased with increasing powder content for both LS and FA; however, the increase of the FA was higher than the LS due to the pozzolanic effect. SCC with a coarse aggregate size of 16 mm showed higher strength than 10 mm for both powders. Similarly, the modulus of elasticity increased with the amount of powder material. Inelastic properties, which are rarely found in the literature for SCC, were determined by measuring the initial and critical stresses. Crack formation in SCC begins under lower stresses (corresponding to lower initial stresses) than in normal concretes, while critical stresses indicate a more brittle behavior by taking higher values.