• 대한수학회보
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• 제25권2호
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• pp.179-183
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• 1988

In this paper we study a $C^{*}$-dynamical system (A, G, .alpha.) where A is a UHF-algebra, G is a finite abelian group and .alpha. is a *-automorphic action of product type of G on A. In [2], A. Kishimoto considered the case G= $Z_{n}$, the cyclic group of order n and investigated a condition in order that the fixed point algebra $A^{\alpha}$ of A under the action .alpha. is UHF. In later N.J. Munch studied extremal tracial states on $A^{\alpha}$ by employing the method of A. Kishimoto [3], where G is a finite abelian group. Generally speaking, when G is compact (not necessarily discrete and abelian), $A^{\alpha}$ is an AF-algebra and its ideal structure was well analysed by N. Riedel [4]. Here we obtain some conditions for $A^{\alpha}$ to be UHF, where G is a finite abelian group, which is an extension of the result of A. Kishimoto.oto.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.26-29
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• 2006

A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

• 대한약리학회지
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• 제32권2호
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• pp.211-219
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• 1996

The inhibitory effect of cyclosporin A (CsA) on nitric oxide production is not related to the immunosuppressive action of the drug, but to the renal toxicity and arterial hyper-tension. In this study the experimental interventions to reverse the inhibition of nitric oxide production by cyclosporin A in rat aortic smooth muscle cells were examined. CsA inhibited the accumulation of nitrite, the stable end product of nitric oxide, in culture media in a concentration $(0.1{\sim}100{\mu}g/ml)-dependent$ manner. The inhibitory effect of CsA on nitrite accumulation were not antagonized by arginine (10 mM), a substrate of nitric oxide synthase, nor by calcium ionophore A23187 $(7{\mu}M)$. Forskolin, an activator of adenylate cyclase, which enhanced iNOS induction at transcriptional level, completely reversed the inhibitory action of CsA on nitrite accumulation. However, PMA (2 nM) and PDB (50 nM), PKC activators, increased the inhibitory action of CsA on nitrite accumulalion. From these results, it is suggested that cyclic AMP-elevating agents may be candidates of therapeutic agents in prevention and treatment of renal toxicity and arterial hypertension induced by CsA. Among conventional antihypertensive drugs, calcium channel blockers and ${\alpha}-blockers$ are preferred to ${\beta}-blockers$.

• 유통과학연구
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• 제19권9호
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• pp.53-64
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• 2021

Purpose: The current study aims and reviews the current state of research in green awareness' distribution structure using the ecological theory of Ted Hughes who was regarded as one of the best English poets of the 20 century. Ted poetry has innovated ecological distribution. It has inspired so many young people to have a positive energy impact on the environment. Research design, data and methodology: Action research design is an approach used extensively in qualitative content analysis. This design starts by adopting an exploratory claim that develops the research objectives, hence instigating the action process, which involves several strategies. This type of design involves a cyclic process of stance then action. Results: According to the investigation, there are nine solutions that can deal with the green distribution based on previous literature review, applying an ecological approach of Ted Hughes to green awareness distribution. The solutions figured out that Ted's novels had an innovative impact on the environment as it is clear that information is given to society. Conclusions: It is observed that having a highly professional environment is good enough for a structure to go green. But, on the other hand, polluting our environment can endanger species by causing health diseases and environmental problems.

• 대한약리학회지
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• 제27권2호
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• pp.167-181
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• 1991

Adenylate cyclase 효소를 활성화시키는 약물인 Forskolin의 흰쥐 적출관류 부신으로부터 Ach, excess $K^+$, McN-A-343 및 caffein에 의한 catecholamines (CA) 분비작용에 대한 영향을 검색하고, 그 기전을 규명코자 연구를 시행하여 다음과 같은 연구결과를 얻었다. Forskolin (1.0 uM)은 흰쥐 부신적출정맥내로 1분동안 관류시킨 후 Ach(50 ug), excess $K^+$(56 mM), DMPP (100 uM) 및 caffeine (0.3 mM)에 의한 CA 분비작용을 현저히 증강시켰으나 McN-A-343에 의한 CA분비작용에는 영향을 미치지 않았다. Forskolin 자체는 CA분비작용을 일으키지 못하였다. 또한 세포의 calcium을 제거한 상태에서도 위 약물에 의한 CA분비작용에 대하여 유의한 증강작용을 나타내었다. 그러나 McN-A-343의 CA작용에는 영향이 없었으나 위의 약물의 CA분비작용을 유의하게 강화시켰다. Cyclic AMP를 증가시키는 약물로 알려져 있는 dibutyryl cyclic AMP (DBcAMP)는 300 uM농도를 1분간 관류시 Ach, excess $K^+$ 및 DMPP의 CA 분비작용을 뚜렷하게 증강시켰으나 McN-A-343 및 caffeine의 CA분비에는 별다른 영향이 없었다. DBcAMP 자체도 CA분비작용에는 영향을 미치지 못하였으나 또한 DBcAMP는 세포의 칼슘제거시에도 위의 약물에 의한 CA분비작용을 의의있게 증강시켰다. 그렇지만, McN-A-343의 CA분비작용은 증강시키지 못하였다. 이상의 연구결과로 보아 Forskolin는 adenylate cyclase를 활성화 시킴으로써 cyclic AMP 농도를 증가시켜 세포내로 칼슘유입을 증강시키며, 또한 세포내의 칼슘이동에도 관여함으로써 cholinergic nicotinic stimulation 및 depolarization에 의한 CA분비작용을 상승시키는 것으로 사료되어진다.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.731-739
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• 1997

The aim of present study is to investigate the effects of cGMP on hyperpolarization activated inward current ($I_f$), pacemaker current of the heart, in rabbit sino-atrial node cells using the whole-cell patch clamp technique. When sodium nitroprusside (SNP, $80{\mu}M$), which is known to activate guanylyl cyclase, was added, $I_f$ amplitude was increased and its activation was accelerated. However, when $I_f$ was prestimulated by isopreterenol (ISO, $1{\mu}M$), SNP reversed the effect of ISO. In the absence of ISO, SNP shifted activation curve rightward. On the contrary in the presence of ISO, SNP shifted activation curve in opposite direction. $8Br-cGMP(100\;{\mu}M)$, more potent PKG activator and worse PDE activator than cGMP, also increased basal $I_f$ but did not reverse stimulatory effect of ISO. It was probable that PKG activation seemed to be involved in SNP-induced basal $I_f$ increase. The fact that SNP inhibited ISO-stimulated $I_f$ suggested cGMP antagonize cAMP action via the activation of PDE. This possibility was supported by experiment using 3-isobutyl-1-methylxanthine (IBMX), non-specific PDE inhibitor. SNP did not affect $I_f$ when $I_f$ was stimulated by $20{\mu}M$ IBMX. Therefore, cGMP reversed the stimulatory effect of cAMP via cAMP breakdown by activating cGMP-stimulated PDE. These results suggest that PKG and PDE are involved in the modulation of $I_f$ by cGMP: PKG may facilitate $I_f$ and cGMP-stimulated PDE can counteract the stimulatory action of cAMP.

• Steel and Composite Structures
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• 제22권1호
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• pp.141-159
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• 2016

Commonly in steel frames, steel beam and concrete slab are connected together by shear keys to work as a unit member which is called composite beam. When a composite beam is subjected to positive bending, flexural strength and stiffness of the beam can be increased due to "composite action". At the same time despite these advantages, composite action increases the strain at the beam bottom flange and it might affect beam plastic rotation capacity. This paper presents results of study on the rotation capacity of composite beam connected to Rectangular Hollow Section (RHS) column in the steel moment resisting frame buildings. Due to out-of-plane deformation of column flange, moment transfer efficiency of web connection is reduced and this results in reduction of beam plastic rotation capacity. In order to investigate the effects of width-to-thickness ratio (B/t) of RHS column on the rotation capacity of composite beam, cyclic loading tests were conducted on three full scale beam-to-column subassemblies. Detailed study on the different steel beam damages and concrete slab damages are presented. Experimental data showed the importance of this parameter of RHS column on the seismic behavior of composite beams. It is found that occurrence of severe concrete bearing crush at the face of RHS column of specimen with smaller width-to-thickness ratio resulted in considerable reduction on the rate of strain increase in the bottom flange. This behavior resulted in considerable improvement of rotation capacity of this specimen compared with composite and even bare steel beam connected to the RHS column with larger width-to-thickness ratio.

• Bulletin of the Korean Chemical Society
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• 제15권2호
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• pp.132-138
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• 1994

Bis(diethylamino)aluminum hydride was utilized in a systematic study of the approximate rates and stoichiometry of the reaction of excess reagent with 55 selected organic compounds containing representative functional groups under standardized conditions (THF, $0^{\circ}C$, reagent to compound=4 : 1) in order to define the characteristics of the reagent for selective reductions. The reducing action of BEAH was also compared with that of the parent aluminum hydride. The reducing action of the reagent is quite similar to that of aluminum hydride, but the reducing power is much weaker. Aldehydes and ketones were readily reduced in 1-3 h to the corresponding alcohols. However, unexpectedly, a ready involvement of the double bond in cinnamaldehyde was realized to afford hydrocinnamyl alcohol. The introduction of diethylamino group to the parent aluminum hydride appears not to be appreciably influential in stereoselectivity on the reduction of cyclic ketones. Both p-benzoquinone and anthraquinone utilized 2 equiv of hydride readily without evolution of hydrogen, proceeded cleanly to the 1,4-reduction products. Carboxylic acids and acid chlorides underwent reduction to alcohols slowly, whereas cyclic anhydrides utilized only 2 equiv of hydride slowly to the corresponding hydroxylacids. Especially, benzoic acid with a limiting amount of hydride was reduced to benzaldehyde in a yield of 80%. Esters and lactones were also readily reduced to alcohols. Epoxides examined all reacted slowly to give the ring-opened products. Primary and tertiary amides utilized 1 equiv of hydride fast and further hydride utilization was quite slow. The examination for possibility of achieving a partial reduction to aldehydes was also performed. Among them, benzamide and N,N-dimethylbenzamide gave ca, 90% yields of benzaldehyde. Both the nitriles examined were also slowly reduced to the amines. Unexpectedly, both aliphatic and aromatic nitro compounds proved to be relatively reactive to the reagent. On the other hand, azo- and azoxybenzenes were quite inert to BEAH. Cyclohexanone oxime liberated 1 equiv of hydrogen and utilized 1 equiv of hydride for reduction, corresponding to N-hydroxycyclohexylamine. Pyridine ring compounds were also slowly attacked. Disulfides were readily reduced with hydrogen evolution to the thiols, and dimethyl sulfoxide and diphenyl sulfone were also rapidly reduced to the sulfides.

• Journal of Ginseng Research
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• 제47권6호
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• pp.706-713
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• 2023

Background and objective: The ability to inhibit aggregation has been demonstrated with synthetically derived ginsenoside compounds G-Rp (1, 3, and 4) and ginsenosides naturally found in Panax ginseng 20(S)-Rg3, Rg6, F4, and Ro. Among these compounds, Rk3 (G-Rk3) from Panax ginseng needs to be further explored in order to reveal the mechanisms of action during inhibition. Methodology: Our study focused to investigate the action of G-Rk3 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin α_IIbβ₃ using flow cytometry, intracellular calcium mobilization, dense granule secretion, and thromboxane B₂ secretion. In addition, we checked the regulation of phosphorylation on PI3K/MAPK pathway, and thrombin-induced clot retraction was also observed in platelets rich plasma. Key Results: G-Rk3 significantly increased amounts of cyclic adenosine monophosphate (cAMP) and led to significant phosphorylation of cAMP-dependent kinase substrates vasodilator-stimulated phosphoprotein (VASP) and inositol 1,4,5-trisphosphate receptor (IP₃R). In the presence of G-Rk3, dense tubular system Ca²⁺ was inhibited, and platelet activity was lowered by inactivating the integrin αIIb/β₃ and reducing the binding of fibrinogen. Furthermore, the effect of G-Rk3 extended to the inhibition of MAPK and PI3K/Akt phosphorylation resulting in the reduced secretion of intracellular granules and reduced production of TXA₂. Lastly, G-Rk3 inhibited platelet aggregation and thrombus formation via fibrin clot. Conclusions and implications: These results suggest that when dealing with cardiovascular diseases brought upon by faulty aggregation among platelets or through the formation of a thrombus, the G-Rk3 compound can play a role as an effective prophylactic or therapeutic agent.

• Applied Biological Chemistry
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• 제9권
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• pp.1-7
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• 1968

뉴우질랜드 시금치(Tetragonia expansa)잎의 절편(切片)을 $2.0{\times}10^{15}$ quanta $cm^{-2}$ $sec.^{-1}$의 일정 레벌의 에너지를 가지는 각파장(各波長)의 광선(光線)을 쪼였을때 일어나는 violaxanthin의 de-epoxidation과 zeaxanthin의 epoxidationq 반응(反應)의 action spectrum을 측정(測定)하였다. De-epoxidation의 action spectrum에서는 480nm와 648nm에 두 개의 주 피이크를 나타내었고 청색광선(靑色光線)은 적색광선(赤色光線)보다 더 유효(有效)하였으며, 700nm 이상의 파장(波長)에서는 효과(?果)가 없었다. 한편 expoxidation의 spectrum은 440과 670nm 근처(近處)에 피이크를 나타내었고 이것 또한 청색광(靑色光)이 적색광(赤色光)보다 유효(有效)하였으나 700nm 이상의 파장(波長)에 있어서 확실(確實)히 효과(?果)를 나타내었다. Epoxidation과 de-epoxidation의 상반(相反)되는 두 반응(反應)의 정(正)의 결과(結果)는 하나의 cycle scheme 즉 산소(酸素)와 광반응생성물(光反應生性物)을 소비(消費)하는 "violaxanthin cycle"로 보아진다. Action spectra가 지시하는바와 같이 청색광(靑色光)이 적색광(赤色光)보다 더 유효(有效)하다는 것은 청색광(靑色光)에 의한 자극(刺戟)으로 진행(進行)되는 $O_2-uptake$로 간주(看做)된다. 두 action spectrum간(間)의 차이점(差異點)들은 다분히 두 개의 광합성기구(光合成機構)가 동시(同時)에 관련(關聯)되고 있다는 것을 시사한다. 그러므로 violaxanthin cycle은 청색광(靑色光)에 위해서 발생(發生)하는 과잉(過剩)한 광합성생성물(光合成生性物)의 소비경로(消費經路)로서, 또는 그들 생성물(生性物)을 어떤 다른 형태(形態)의 에너지로 전환(轉換)하는 역할(役割)을 하는것이라 보아진다.