• Title/Summary/Keyword: small action

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Prying Action of Spliced Reinforcements in Tension (인장 겹침이음에서 프라이 거동의 영향)

  • Chun, Sung-Chul;Choi, Dong-Uk;Ha, Sang-Su;Oh, Bo-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.1085-1088
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    • 2008
  • Splice of reinforcement is inevitable in reinforced concrete structures and, generally, lap splices are used. Lap length for tension splice is determined from development length in tension. The development length is calculated from an experimental model which was based on data of tests on anchorage and splice. Longitudinal reinforcements in flexural members are deformed and, therefore, prying action happens in spliced reinforcements unlike anchored reinforcements. The prying action induces tensile stress in cover concrete and this tensile stress plays the same role to a circumferential tensile stress caused by bond. Because splitting failure is assumed to occur when the summation of tensile stresses caused by the prying action and the bond is equal to the tensile strength of the concrete, the prying action reduces the bond strength of spliced reinforcements. A theoretical model for the prying action is developed and effects of the prying action on the bond strength are assessed. The tensile stress by the prying action is proportional to tensile strength and modulus of elasticity of reinforcements. In addition, the tensile stress is inversely proportional to spacing of reinforcements. Consequently, longer splice length is required for spliced reinforcements with small spacing in flexible members.

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Impairment of a parabolic bursting rhythm by the ectopic expression of a small conductance $Ca^{2+}$-activated $K^+$ channel in Aplysia neuron R15

  • Lee, Yong;Han, Jin-Hee;Lim, Chae-Seok;Chang, Deok-Jin;Lee, Yong-Seok;Heun Soh;Park, Chul-Seung;Kaang, Bong-Kiun
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.38-38
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    • 2003
  • The electrical properties of neurons are produced by the coordinated activity of ion channels (Hille, 1992). $K^{+}$ channels play a key role in shaping action potentials and in determining neural firing patterns. Small conductance $Ca^{2+}$-activated $K^{+}$ (S $K_{Ca}$ ) channels are involved in modulating the slow component of afterhyperpolarization (AHP) (Kohler et al., 1996). Here we examine whether rat type 2 S $K_{Ca}$ (rSK2) channels can affect the shape of the action potential and the neural firing pattern, by overexpressing rat SK2 channels in Aplysia neuron R15. Our results show that rSK2 overexpression decreased the intraburst frequency and changed the regular bursting activity of neurons to an irregular bursting or beating pattern in R15, Furthermore, the overexpression of rSK2 channels increased AHP and reduced the duration of the action potential. Thus, our results suggest that ectopic S $K_{Ca}$ channels play an important role in regulating the filing pattern and the shape of the action potential.ntial.

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Temperature-dependency of $Ca^{2+}$ Effect on the Electrical Activity of Rabbit SA Node (동방결절 전기적 특성에 대한 $Ca^{2+}$ 효과의 온도에 따른 변화)

  • Ho, Won-Kyung;Kim, Ki-Whan;Hwang, Sang-Ik
    • The Korean Journal of Physiology
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    • v.21 no.1
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    • pp.1-12
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    • 1987
  • There is evidence that the effect of extracellular $Ca^{2+}$ on heart rate is temperature-dependent: at $38^{\circ}C$ excess $Ca^{2+}$ induces positive chronotropic response, whereas at $30^{\circ}C$ there is no significant chronotropic effect of $Ca^{2+}$. The cause of this temperature-dependency, however, remains still unclear. Therefore, this study was undertaken to investigate the chronotropic effect of external $Ca^{2+}$ at different temperature in the isolated rabbit atria and in the small strips of SA node cut perpendicularly to crista terminalis. In the isolated atria, the $Ca^{2+}$ effect was temperature-dependent: at $35^{\circ}C$ excess $Ca^{2+}$ evoked positive chronotropic response, while at $30^{\circ}C$ there was no significant changes in sinus rate. On the contrary, in the small SA strips external $Ca^{2+}$ induced negative chronotropic effect. At $35^{\circ}C$ changes in $Ca^{2+}$ concentration from 2 to 4, 6, and 10 mM decreased the sinus rate by $2.7{\pm}1.6%$, $11.2{\pm}3.7%$ and $23.2{\pm}8.1%$ respectively. Lowering the temperature to $30^{\circ}C$, the negative chronotropic effect of $Ca^{2+}$ became greater. With intracellular microelectrodes transmembrane potential was recorded in the small SA strips at $30^{\circ}C$, $35^{\circ}C$ and $38^{\circ}C$. As temperature increased from 30 to $38^{\circ}C$, sinus rate was accelerated by $13/min/^{\circ}C$, $APD_{50}$(action ptential duration from peak to 50% repolarization) decreased by $5\;msec/^{\circ}C$, and amplitude of action potential was slightly decreased. With an increase in $Ca^{2+}$ concentrations from 0.5 to 6 mM, overshoot increased and MDP decreased. These $Ca^{2+}$ effects on the overshoot and MDP of action potentials were not altered by temperature. But the $Ca^{2+}$ effects on the rates of diastolic depolarization, systolic depolarization and repolarization were modified by temperature. Discrpancy of the chronotropic effects of $Ca^{2+}$ between isolated atria and small SA strips was discussed.

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Studies on Diuretic Action of Bumetanide (Bumetanide의 이뇨작용에 관한 연구)

  • 고석태;김일용
    • YAKHAK HOEJI
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    • v.29 no.3
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    • pp.130-143
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    • 1985
  • Bumetanide, when given intravenously in dogs, induced a potent diuresis with an increased amounts of sodium and potassium excreted in urine due to inhibition of reabsorbing them in renal tubule. Furthermore, clearances of osmolar substance and para-aminohippuric acid were increased, but clearace of free water diminished without any change of creatinine clearance. Bumetanide, administered directly into a renal artery, elicited diuresis only in the infused(experimental) kidney by the same mode of action as in the intravenous cases in renal function of the dog. Renal effects of intravenous bumetanide after pretreatment with the small dose of indomethacin (5.0mg/kg) revealed reduction only in clearance of paraaminohippuric acid. However the much dose of indomethacin (5.0mg/kg+5.0mg/kg/hr) or arachidonic acid showed a significant inhibition in the change rates of all renal function by bumetanide. Morover, pretreatment of probenecid also made a marked reduction in renal effects induced by bumetanide. From the above results, it is thought that bumetanide causes diuretic action due to dual mechanism inhibiting reabsorption of electrolytes in loop of Henle and increasing blood flow in kindney, that are provoked through the mediation of prostaglandins.

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Design of an Alpine Skiing Game Using ActionScript 3.0

  • Bai-Tiantain, Bai-Tiantain;Park, Jong-Hoon;Kim, Chul-Won
    • Journal of information and communication convergence engineering
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    • v.10 no.2
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    • pp.168-174
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    • 2012
  • Flash is the most popular 2D animation and game development software, supporting vector and media technology at the core, which enables the development of small and pithy games. It is widely used in Web animation, courseware, TV commercials, game development, and other works of design. In this paper, we propose a control movement function and auxiliary functions for an alpine skiing game based on ActionScript 3.0. The control movement function is designed with moving phases (i.e., free fall, sliding, projectile, and landing). The auxiliary functions include drawing path, start/restart movement, and saving the highest score. In addition, for the visual design of our game, we designed animations in connection with a character and background. In order to facilitate testing the friction, users can input a chosen friction value. Without user input, the friction default is set at 0.97.

Effects of Jeo Ryong-tang water Extract on Renal Function in Rabbit and Dog (저령탕전탕액(猪令湯煎湯液)이 가토(家兎) 및 개의 신장기능(腎臟機能)에 미치는 영향(影響))

  • Jo, Sang-Seop
    • Journal of Sasang Constitutional Medicine
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    • v.2 no.1
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    • pp.213-221
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    • 1990
  • Effect of Jeo Ryong-Tang water Extract on Renal Function in Rabbit and Dog. In order to investigate the Pharmacological action of Jeo Ryoung-Tang on renal function, this study was performed in rabbit and dog, making use of it's water extract. Jeo Ryoung-Tang water extract (JRWE), when given into ear vein of rabbits, produced diuresis in a small dose, but antidiuresis in a large dose. Diuretic action of JRWE accompanied the increase of glomerular filtration rate (GFR), renal plasma flow (RPF) and amounts of $Na^+$ in exdreated in urin, but fractional excretion of filtered $Na^+$ was not changed. JRWE, when injected into proleg's vein of dog, produced diuresis, At this time, changes of renal function were similar to that of diuresis in rabbit. JRWE, when infused into a renal artery of dog, exhibited the diuresis in both kidney. It is thought that JRWE, when given into vein of rabbit or dog, induces the diuresis, and the mechanism of it's diuresis is the increase of renal plasma flow through secondary action by some endogenous humoural substance.

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Studies on the Efficacy of Combined Preparation of Crude Drugs (XII) -Effect of ‘Daeshiho-Tang’ on the Central Nervous System and Digestive System- (생약복합제제의 약효연구 제12보1) -대시호탕이 중추신경계 및 소화기계에 미치는 영향-)

  • Hong, N.D.;Chang, I.K.;Jung, H.C.;Kim, N.J.
    • Korean Journal of Pharmacognosy
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    • v.14 no.1
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    • pp.9-16
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    • 1983
  • Experimental studies were implemented to evaluate clinical efficacy of 'Daeshiho-Tang' and to validate Oriental medicine description of the recipe which has been widely used in metabolic diseases and febrile diseases. Following results were obtained; 1. Suppressive action was shown on convulsion due to cerebrocortical causes but no such action was noted either myelic or diencephatic causes in mice. 2. Analgesic and antipyretic actions were recognized in mice, rats and rabbits. 3. Antispasmodic actions were recognized on contraction of the ileum induced by $BaCl_2$ and histamine in mice and guinea-pigs. 4. Transport accelerating action of the small intestine was gained in mice.

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Experimental studies on the efficacy of Siljangsan (실장산(實腸散)이 위장관(胃腸管)에 미치는 영향(影響))

  • Kong, Hyeon-Sig;Rhu, Bong-Ha;Rark, Dong-Won;Ryu, Ki-Won
    • The Journal of Internal Korean Medicine
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    • v.15 no.2
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    • pp.197-208
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    • 1994
  • In order to investigate the efficacy of Siljangsan by using the experimental animals, the action of gastric juice secretion, antiulcer. transport rates in the intestine and anti-cathartic action were studied. The following results were obtained. 1. Preventive effects on ulcer induced by pylorus-ligated and Ethanol-HCI were recognized 2. Suppression effects on gastric juice secretinon, free of acidity and total acidity were recognized, but pepsin output was not recognized. 3. For the transport ability of intestine of mice, the ability of small intestine was activated and large intestine was suppressed in the group administrated 4. Anti-cathatic action of mice induced by castor oil was recognized. According to above results, effect based on oriental medical reference was consistent with the actual experimental effect.

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Diuretic action of hoelen in the dog (복령의 이뇨작용)

  • ;;Lee, Dohn Ill;Moon, Yung Hee
    • YAKHAK HOEJI
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    • v.18 no.1
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    • pp.39-48
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    • 1974
  • Intravenously administered total water extract of Hoelen, (Pachymae fungus) in a dose of 10mg/kg and its methanol lextract, in a smaller dose than total water extract, produced significantly increase on urinary volume, sodium nad potassium excretion, and osmolar nad free water clearances. Increasing the doses produced more pronounced renal responses. Glomerular filtration rate and renal plasma flow changed littl with both extract. On the contrary, water extract from residue obtained on extraction with organic solvents exhibited no significant changes on the parameters of the renal function. In experiments, in which the total water extract was infused directly into a renal artery and urines from both ureters were collected separetely, a small dose of 0.3mg/kg/min showed no diuresis, but a large dose of 1.0mg/kg/min elicited diuretic action even on the contralateral kindneys. It is, therfore, concluded that Hoelen induces diuresis, mainly by inhibiting reabsorption of electrolytes in the renal tubules, and that the renotropic action may be mediated by some endogenous humoral substances.

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The Effects of Organic Acidic Drugs on the Absorption, Excretion and Diuretic Action of Furosemide (유기산성약물이 푸로세미드의 흡수, 배설및 이뇨효과에 미치는 영향)

  • 염윤희;용재익
    • YAKHAK HOEJI
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    • v.31 no.5
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    • pp.273-279
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    • 1987
  • The effects of organic acidic drugs on the absorption, excretion and diuretic action of furosemide were studied. Cefalexin, p-aminohippuric acid (PAH), ibuprofen and p-amino salicylic acid (PAS) were selected as organic acidic drugs. The in situ absorption rate and absorption rate constant of furosemide (30$\mu{M}$) were significantly (p<0.05) decreased by 30$\mu{M}$ of cefalexin, PAH, ibuprofen and PAS in rat small intestine. The plasma concentration of furosemide was significantly (p<0.01) increased by cefalexin, PAH and ibuprofen in rabbits. But the urinary excretion rate, renal clearance and diuretic action of furosemide were significantly (p<0.05) decreased by cefalexin, PAH, ibuprofen and PAS in rabbits.

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