• The Korean Journal of Physiology
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• 제20권1호
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• pp.31-41
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• 1986

The sufficient myoplasmic $Ca^{++}$ to react with the contractile proteins is necessary to induce contraction of a cardiac muscle. These $Ca^{++}$ for the production of muscle contraction are supplied from the three recognized $Ca^{++}$ sources; internal $Ca^{++}$ release via the sarcoplasmic reticulum(SR), $Ca^{++}$ influx through a gated Ca-channel in the membrane as a Isi, and $Ca^{++}$ transport by the mechanism of Na/ca exchange. However, it is still controversial which $Ca^{++}$ sources act as a main contributor for myoplasmic $Ca^{++}$, Therefore, this study was undertaken in order to examine the $Ca^{++}$ sources for the contraction of frog ventricle. There is evidence that the SR is sparse in frog ventricular fibers, and that T-tubules are absent. Isolated ventricular strips of frog, Rana nigromaculata, were used in this experiment. Isometric tension was recorded by force transducer, and membrane potentials of ventricular muscles were measured through the intracellular glass microelectrodes, which were filled with 3M KCI and had resistance of $30{\pm}50M{\Omega}$. All experiments were performed at room temperature in a tris·buffered Ringer solution which was aerated with 100% $O_2$. Isotonic high K, low Na solution was used to induce K-contracture, K-contracture appeared at the concentration of 20 to 30mM-KCI and was potentiated in parallel with the increase in KCI concentration. The contracture had two components: an initial rapid phasic and a subsequent slow tonic contractile responses. Membrane Potentials measured at normal Ringer solution(2.5mM KCI) was -90 to -100 mV, and decreased linearly as the KCI concentration increased; -55mV at 20mM.KCI, -45mV at 30 mM.KCI, -30 mY at 50 mM.KCI, and -12 mV at 100 mM.KCI. K-contracture was evoked firstly at the membrane potential of -45 mV. The contracture was potentiated by the increase of bathing extracellular $Ca^{++}$ concentration. However, in the absence of $Ca^{++}$ the contracture was almost not induced by 50 mM.KCI solution. Caffeine(20mM) in normal Ringer solution, which is known to release $Ca^{++}$ from SR without substantial effects on the $Ca^{++}$ fluxes across the surface membrane, did not affect membrane potential and also not initiate contracture, but the caffeine in 20 mM-KCI Ringer solution produced a contracture. Above results suggest that the main $Ca^{++}$ source for the K·contracture of frog ventricle is $Ca^{++}$ influx through the voltage-dependent Ca-channel, and that in the K-contracture at the concentration of 100 mM-KCI, the mechanism of Na/ca exchange also partly contributs, in addition to the $Ca^{++}$ influx.

• 대한원격탐사학회지
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• 제21권4호
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• pp.253-271
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• 2005

Landsat 시계열 영상과 실측수온자료를 이용하여 한강 수계 댐호들의 표면수온과 계절적 성층현상을 분석하였다. 1994년에서 2004년까지 29회에 걸쳐 얻어진 Landsat-5, 7 열적외선 영상으로부터 NASA 경험식을 이용하여 호수의 표면수온을 추출하였고, 이를 하천형 댐호인 파로호, 춘천호, 의암호, 청평호, 팔당호의 표층수온, 그리고 호소형 댐호인 소양호의 상층수온(수심 10m) 자료와 비교하였다. 십 수 년간 매월 1회 측정된 수온자료를 위성관측 날짜에 보간하여 사용하였음에도 불구하고, 하천형 댐호들에서는 수온오차(위성관측수온-실측보간수온)의 표준 편차가 $2^{\circ}C$ 이하인 영상이 94개로서, 새로운 통계적 대기보정을 적용할 수 있었다. 실측보간수온과 위성관측수온의 상관계수는 소양호가 0.915 (대기보정 후 0.950), 다른 호수는 0.951-0.980 (대기보정 후 0.979-0.997)로서, 높은 상관성을 보여주었다. 이는 수심이 얕고 인위적인 물의 유입과 유출이 연중 계속되는 하천형 댐호의 표층에는 혼합층이 상시 존재하고 수온의 일변화 및 월변화가 비교적 연속적이기 때문인 것으로 해석되었다. 그러나 소양호에서는 4-7월에 위성관측수온이 실측보간수온보다 $3-5^{\circ}C$ 더 높게 나타나는 이상 수온오차가 관찰되었다. 한강 수계의 최상류에 위치하며 수심이 깊고 자연적인 유입량만이 존재하는 소양호에서 이 시기는 상층수의 물리적 혼합현상이 없이 매우 안정적이고, 일조량 증가에 따라 호수 상층부에 수온약층이 발달하기 때문에, 수심 10m에서 측정된 실측수온보다 위성으로 관측된 표면수온이 연중 비교적 건조한 이 시기에 더 높게 나타나는 것으로 밝혀졌다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.392-400
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• 2002

We have previously found that the saponins but not other components in the ginseng reduce the secretion of catecholamines (CAs) from bovine adrenal chromaffin cells, a model of sympathetic nerves, evoked by acetylcholine (ACh) due to the blockade of $Na^+$ influx through nicotinic ACh receptor-operated cation channels, and it has been concluded that the inhibitory effect may be associated with the anti-stress action of ginseng. However, the saponins, which showed the great reduction of the CA secretion, were mainly the protopanaxiatriols. The protopanaxadiol and oleanolic acid saponins had a little or little such effect. Recent studies demonstrated that the oligosaccharides connected to the hydroxyl groups of the aglycones of the saponins are in turn hydrolyzed by gastric acid and enzymes in the intestinal bacteria when the ginseng is orally administrated. In this study, the effects of their major 6 kinds of metabolites on the secretion of CAs were investigated. All metabolites (M1, 2, 3 and 5 derived from the protopanaxadiols, and M4 and 11 from the protopanaxiatriols) reduced the ACh-evoked secretion from the cells. In the metabolites, the M4 inhibition was the most potent ($IC_{50}({\mu}M):M4(9)$ < M2 (18) < M3 (19) < M1l (22) < M5 (36) < MI (38)). Although M4 also reduced the CA secretion induced by high $K^+$, a stimulation activating voltage-sensitive $Ca^{2+}$ channels, the inhibitory effect was much less than that on the ACh-evoked secretion. M4 inhibited the ACh-induced $Na^+$ influx into the cells in a concentration-dependent manner similar to that of the inhibition of the ACh-evoked secretion. When the cells were washed by the incubation buffer after the preincubation of the cells with M4 and then incubated without M4 in the presence of ACh, the M4 inhibition was not completely abolished. On the other hand, its inhibition was maintained even by increasing the external ACh concentration. These results indicate that the saponins are metabolized to the more active substances in the digestive tract and the metabolites attenuate the secretion of CAs from bovine adrenal chromaffin cells stimulated by ACh due to the noncompetitive blockade of the ACh-induced $Na^+$ influx into the cells. These findings may further explain the anti-stress action of ginseng.

• 무역학회지
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• 제45권4호
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• pp.137-152
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• 2020

The increase in national income, the expansion of transportation network, the increase in leisure time, and the influx of foreign tourists in the era of internationalization, the influx of the outside population of Jeju region increased rapidly until 2020. However, the corona 19 (Covid-19) incident that began in January 2020 has hit the entire industry, and the tourism industry in Jeju has also been greatly damaged. However, in the second half of 2020, with some calming of the Corona 19 situation and difficult to leave overseas, the number of visitors to Jeju Island is increasing again as Koreans choose Jeju Island as their domestic tourism. This study analyzed the capacity of Jeju's external population based on the Contingent Valuation Method, and based on this, attempted to suggest policy recommendations for Jeju. The size of accommodations such as the density of visitors, toilets, and rest areas were excluded from consideration, and the level of securing the parking lot already exceeded the capacity, and the rate of securing the parking lot was 93.4%. In the case of accommodation, the total number of available rooms is 88,691, even if one guest per room is assumed, which is 32,372,215 per year, which is sufficient in terms of visitor capacity. To analyze the aspects of psychological capacity, this study analyzed whether the residents are feeling psychological discomfort through three methods of road congestion, garbage disposal, and sewage treatment through Contingent Valuation Method. However, the inconvenience caused by the increase of visitors and the effect of continuous population influx is working in combination, and it has the limitation that the effects of these independent factors cannot be specifically separated. As a result of the study, discomfort has already been recognized in terms of psychological capacity among the factors of capacity, and it was estimated that a cost of about 45 billion won per year was incurred as a result of deriving psychological costs through Contingent Valuation Method. In the future, a policy review is needed to resolve or maintain the perception of this discomfort through continuous management. Accordingly, it is necessary to recognize that the increase of visitors leads to the psychological discomfort of the residents, and to seek a policy alternative that can simultaneously increase the number of visitors and the comfort of the residence.

• Journal of Ginseng Research
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• 제47권6호
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• pp.755-765
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• 2023

Background: Caveolin-1, the scaffolding protein of cholesterol-rich invaginations, plays an important role in store-operated Ca²⁺ influx and its phosphorylation at Tyr14 (p-caveolin-1) is vital to mobilize protection against myocardial ischemia (MI) injury. SOCE, comprising STIM1, ORAI1 and TRPC1, contributes to intracellular Ca²⁺ ([Ca²⁺]_i) accumulation in cardiomyocytes. The purified extract of steamed Panax ginseng (EPG) attenuated [Ca²⁺]_i overload against MI injury. Thus, the aim of this study was to investigate the possibility of EPG affecting p-caveolin-1 to further mediate SOCE/[Ca²⁺]_i against MI injury in neonatal rat cardiomyocytes and a rat model. Methods: PP2, an inhibitor of p-caveolin-1, was used. Cell viability, [Ca²⁺]_i concentration were analyzed in cardiomyocytes. In rats, myocardial infarct size, pathological damages, apoptosis and cardiac fibrosis were evaluated, p-caveolin-1 and STIM1 were detected by immunofluorescence, and the levels of caveolin-1, STIM1, ORAI1 and TRPC1 were determined by RT-PCR and Western blot. And, release of LDH, cTnI and BNP was measured. Results: EPG, ginsenosides accounting for 57.96%, suppressed release of LDH, cTnI and BNP, and protected cardiomyocytes by inhibiting Ca²⁺ influx. And, EPG significantly relieved myocardial infarct size, cardiac apoptosis, fibrosis, and ultrastructure abnormality. Moreover, EPG negatively regulated SOCE via increasing p-caveolin-1 protein, decreasing ORAI1 mRNA and protein levels of ORAI1, TRPC1 and STIM1. More importantly, inhibition of the p-caveolin-1 significantly suppressed all of the above cardioprotection of EPG. Conclusions: Caveolin-1 phosphorylation is involved in the protective effects of EPG against MI injury via increasing p-caveolin-1 to negatively regulate SOCE/[Ca²⁺]_i.

• 한국습지학회지
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• 제26권3호
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• pp.285-297
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• 2024

본 연구 지역은 김포한강신도시 주변 걸포동, 감정동 일원으로 한강하구 철새도래지역과 인접하여 지속적인 철새류 이입이 이루어지고 있는 지역이며, 해당 지역의 논 습지는 오리·기러기류의 먹이 공급원으로 이용되고 있다. 4개 논 습지(site A~D)를 대상으로 2015년 10월~2022년 3월(총 59차례)까지 관찰된 조류는 총 32과 72종 44,942개체였으며, 상대적으로 넓고 한강과 접한 site D에서 높은 종과 개체수를 보였다. 개발이 시행된 site A와 주변(site B, C) 지역 조사에서는 상대적으로 종수가 낮았으나, 개발이나 간섭의 증가로 섭식지가 소멸되거나 감소하지만, 지속적인 종 이입과 잔여 섭식지를 이용하고 있는 것이 확인되었다. 대상 지역 이입 종 중 우점종이며 법정보호종으로 논 습지를 섭식지로 이용하는 큰기러기를 대상 종으로 선정하고, 분포 특성을 기간별 분석한 결과('15~'22년, 10~3월, 총 30개월) 총 39차례 162회 개체군이 이입되는 등 개체수가 최대 30배까지 증가하였다. 이런 결과는 연구 대상 지역이 한강하구 주요철새도래지역인 장항습지(월동지)와 섭식지간 이용하는 기러기류 실태조사에서 약 5km 내 섭식지를 집중적으로 이용하고 있는 것에 따른 결과라 판단되며, 연구 지역 일대가 이동 거리상 가치가 높은 지역임을 확인할 수 있었고, 향후에도 지속적으로 이용될 것으로 판단된다. 연구 대상 지역의 경우 도시 확장에 따른 섭식지 소멸이나 감소가 발생하더라도 지속적인 종이입이 예상되며, 장래 개발 시 잔존 서식지 보존 외에 대체 섭식지 확보와 밀려나게 될 섭식지로의 원활한 이동을 위한 생태적 코리더의 보호와 코리더와 연결된 징검다리 서식지 확보 대책이 수립돼야 할 것이다.

• Journal of Yeungnam Medical Science
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• 제26권2호
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• pp.93-101
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• 2009

The use of magnesium sulphate has recently increased in anesthesiology and pain medicine. The roles of magnesium sulphate are as an analgesic adjuvant, a vasodilator, a calcium channel blocker and reducing the anesthetic requirement. These effect are primarily based on the regulation of calcium influx into the cell and antagonism of the N-methyl-D-aspartate receptor. We discuss here the clinical effects of magnesium sulphate on anesthesiology and pain medicine.

• 환경위생공학
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• 제5권2호
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• pp.100-104
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• 1990

The geometrical branching pattern was studied through the time by a few parameters: the branching lengths, angles and number of branches. Ratios of moving amounts of nutrients between branches was decreased more in a terminal branch than in a proximal one. As the time increased, the more branches and leaves were also increased, while the influx of sunlight was decreased in the lower portion of inner crown which increased the mortality rate of branches.

• 한국가금학회지
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• 제23권2호
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• pp.99-106
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• 1996

Because of the imminent market opening of livestock and poultry products, Korean poultry industry is faced an influx of contagious diseases from abroad. Due to the increasing trend of intensive and automatic poultry farming, the risks of catching various poultry epidemics are ever more increasing. For the prevention of poultry epidemics, the principles of biosecurity should be observed rather strictly. In addition, regular checking to confirm the presence or absence of latent diseases through serological test, post-mortem examination, and laboratory test, should be carried out routinely. Finally, all kinds of stress factors should be minimized to keep the flock healthy and productive, so that they can achieve their maximum genetic potential.

• 천문학회지
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• 제16권1호
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• pp.19-22
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• 1983

The reduced profiles of $C_2$ 5150.56, CN 3864.32, MgH 5150.20 and FeI 5150.84 lines, representing the penumbra, the penumbra-umbra boundary and the umbra of spa 6403 have been analyzed by comparing them with the synthetic profiles computed from a set of umbral and penumbral models. The results are presented and discussed. It is suggested that there may be a significant lateral flow of pbotospheric radiation into the umbral and penumbral regions of the sunspots.