• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.587-601
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• 2022

In this article, we introduce the concept of contractive mapping, which is generally weak in metric spaces, and show the existence and uniqueness of the fixed point for such mapping in a metric space.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.447-456
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• 1994

In order to elucidate the characterization of receptors involved in inestinal motility of Israeli carp, spontaneously contracting Israeli carp intestinal preperations were prepared and mounted in the organ chambers for contraction traicings using a polygraph. Various contractile agonists were treated and their dose-response curves were constructed. $EC_{50}$ values$(pD_2)$ of each agonist on specific receptors, $pA_2$ values of competitive antagonists against some agonists, and $K_1$, values of noncompetitive antagonists against some agonists were analyzed for characterization of receptors related with the intestinal contraction. Results obtained through the experiments were summarized as follows: 1. Acetylcholine(ACh) exhibited biphasic dose-response curves: initial ACh-induced dose dependent contractions were observed in pM levels but followed by decreased response in in-between concentration levels. Dose dependent contractions reappeared in ${\mu}M$ level. The peaks in pM and ${\mu}M$ levels appeared in $10^{-13}M$ and $3{\times}10^{-5}M$, respectvely. 2. Carbachol(CaCh) exhibited dose dependent contractions from $10^{-9}M$ to $10^{-5}M$, and its $pD_2$ values were higher than those of ACh($5.60{\pm}0.11$). ACh and CaCh exhibited equiactive contractions. Nicotine had no effects on contractile responses of Israeli carp intestine. 3. ACh-induced responses were inhibited by atropine($K_1:7{\times}10^{-8}M$), a muscarinic antagonist, in a non-competitive manner. But CaCh-induced responses were inhibited by both antimuscarinic atropine($pA_2:9.52{\pm}0.14$) and selective $M_2$ antagonistic 4-DAMP($pA_2:8.16{\pm}0.09$), in competitive manners. Nicotine receptor antagonistic decamethonium and hexamethonium had no effects on ACh-and CaCh-induced contractions. Therefore, the cholinergic receptor related to intestinal motility of Israeli carp was assumed as $M_2$ type. 4. In Israeli carp intestine, 5-HT (serotonin) exhibited dose dependent contractions in concentration range from $10^{-8}M$ to $10^{-5}M$. The maximal responses, however, were corresponded to about 50% of those of ACh or CaCh. 5-HT induced contractions were inhibited by $5-HT_2$ antagonistic ketanserin ($K_1: 7.8{\times}10^{-4}M$) in a non-competitive manner, but not by both of anti $5-HT_1$, spiperone and anti $5-HT_3$, MDL-72222. Hence, $5-HT_2$ receptors are suggested to be existed in Isreli carp intestine.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.225-239
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• 1987

The effects of adenosine on the mechanical contractions and electrical activities were investigated in guinea-pig stomach. Spontaneous contractions of the antral region were recorded with force transducer, and the phasic contractions of fundic region were induced by electrical field stimulation. Electrical responses of smocth muscle cells were recored using glass capillary microelectrodes filled with 3M-KCl. Field stimulation was applied transmurally by using a pair of platinum wire (0.5 mm in diameter) placed on both sides of tissue. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows. 1) Adenosine suppressed the spontaneous contractions of antrum in a dose-dependent manner. 2) The inhibitory effect on antral spontaneous contractions was not influenced by the administration of guanethidine $(5{\times}10^{-6}\;M)$ and atropine $10^{-6}\;M$, or in the presence of dipyridamole $10^{-7}\;M$. 3) The phasic contractions of fundus induced by electrical field stimulation, which disappeared rapidly by the addition of tetrodotoxin $(3{\times}10^{-7}\;M)$, were potentiated by adenosine in the presence of guanethidine. 4) Adenosine decreased the amplitude and the maximum rate of rise of slow waves, and the increased amplitude and rate of rise evoked in the high calcium solution or in the presence of TEA were decreased by adenosine. 5) The non-adrenergic, non-cholinergic inhibitory junction potential (IJP) was inhibited by adenosine in the antral region, while the excitatory junction potential (EJP) in the fundic region was potentiated. From the above results, the following conclusions could be made. 1) Adenosine suppresses the spontaneous contractions of antrum strip by the decrease in amplitude and rate of rise of slow waves. 2) The release of neurotransmitter(s) from non-adrenergic, non-cholinergic nerve terminals is inhibited by adenosine.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.6
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• pp.859-865
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• 2002

The aim of this research was to clarify the direct effects of a hot environment on ruminal motility in sheep fed twice a day. In the first experiment, in order to equalize variable factors excluding the ambient temperature between the thermoneutral environment ($23^{\circ}C$, relative humidity 80%) and the hot environment ($32^{\circ}C$, relative humidity 80%), sheep were fed equal amounts of the same quality feed twice a day. The sheep were allowed free access to water for the duration of the two one-hour feeding periods (10:00 am-11:00 am, 5:00 pm-6:00 pm). On the fourth day after exposure to the hot environment, the frequency and strength of ruminal contractions were continuously recorded between 9:30 am and 11:00 pm. Prior to the exposure to a hot environment the frequency and strength of ruminal contractions were recorded in a thermoneutral environment during the period 9:30 am-11:00 pm. In the second experiment, in order to maintain the stomach content of the sheep at equal levels in both environments, the sheep were fed equal amounts of the same quality feed twice a day. Following the completion of the two one-hour feeding periods, a fixed amount of warm water was infused into the rumen. Rumen motility was then recorded during the same period as for the first experiment (9:30 am-11:00 pm). In the first experiment, when the frequency of ruminal contractions prior to (24, 24 frequency/15 min), during (48, 47 frequency/min) and after (22, 19 frequency/min) both the morning and afternoon feeding in a hot environment was compared with the values from the thermoneutral environment (20, 22; 50, 50; 21, 20 frequency/min), there was found to be no difference. However, the strength of ruminal contractions after morning and afternoon feeding (3.7, 3.1 mm Hg) in the hot environment decreased significantly in comparison with the thermoneutral environment (4.3, 3.8 mm Hg). In the second experiment, the frequency of ruminal contractions in the hot environment was not significantly different from that in the thermoneutral environment. The strength of ruminal contractions after ruminal infusion of warm water in the hot environment (morning: 4.6, afternoon: 4.5 mm Hg) was significantly lower than that in the thermoneutral environment (morning: 5.6, afternoon: 5.0 mm Hg). The results suggest that a hot environment acts directly on the strength of ruminal contractions in sheep fed twice a day rather than on the frequency.

• The Journal of Korean Medicine
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• v.23 no.3
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• pp.63-73
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• 2002

Objective : This study aimed to investigate the effects Samyoo-tang Extract (SE) on the vascular systems, including changes in blood pressure and regional cerebral blood flow (rCBF), of male Sprague-Dawley rats. Methods : The changes in rCBF were determined by Laser-Doppler flowmetry through the opened cranial method and norepinephrine (NE)-induced blood vessel contractions were determined by physiograph in the pulmonary artery of isolated rabbits. Results and Conclusion : 1. Contractions evoked by NE ($ED_{50}$) were inhibited significantly by SE in the pulmonary artery. 2. SE inhibited the relaxation of NE induced contractions pretreated with propranolol. 3. SE did not inhibit the relaxation of NE induced contractions pretreated with ODQ and L-NNA. 4. Blood pressure was not affected by SE in rats. 5. rCBF was increased by SE in a dose-dependent manner. 6. Pretreatment with propranolol was increased by SE in a dose-dependent manner in blond pressure. 7. Pretreatment with methylene blue, ODQ and L-NNA did not inhibit SE induced increased in rCBF. These results indicate that SE can relax NE-induced contraction of rabbit blood vessels and increased the changes of rCBF in rats, that relate to the sympathetic nerve system.

• Korean Journal of Veterinary Research
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• v.31 no.2
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• pp.171-178
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• 1991

Effects of catecholamines were investigated on isolated strips of the male cattle oesophageal groove. In the circular muscles of the bottom and longitudinal muscles of the lip. isometric tensions was recorded with isometric myograph in 25ml organ bath. The results were as follows: 1. The muscular activity was different in preparations from the two parts. In the longitudinal muscle from the lip, rhythmic contractions generally occurred. while in the circular muscle from the bottom they were not seen almost. 2. In the circular muscle of the bottom, the increased tone and biphasic contractions were caused by catecholamines. And these contractions were mediated through $\alpha$-excitatory adrenoceptor. Also circular muscle showed minor inhibitory response to catecholamines. And these effects were mediated through $\beta$-inhibitory adrenoceptor. But the circular muscle was more sensitive to the $\alpha$-excitatory effect than $\beta$-inhibitory effect. 3. In logitudinal muslce of the lip. rhythmic contractions were reduced or disappeared by catecholamines(especially propranolol) and these effects were mediated through $\beta$-adrenoceptor.

• The Journal of Internal Korean Medicine
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• v.17 no.1
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• pp.204-209
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• 1996

Several medicinal Plants in Jeonbuk are screened for the contraction or relaxation to the acetylcholine and histamine induced contraction in the isolated rat and guinea pig's trachea smooth muscle. Contractions evoked by acetylcholine and histamine were inhibited by Flos Farfarae, Poria and Rhizoma alismatis, but contractions were increased Tuber Pinelliae, Herba Chelidonii, Fructus Qusqualis, Radix Asari, Semen Perillae, Folium Artemisiae and Fructus Schizamdrae increased the contractions evoked by acetylcholine and histamine. Radix Puerariae, Radix Osterici Koreani, Rhizoma Zingiberis siccatum, Radix Sanguisorbae, Rhizoma Atractylodis, Fructus gardeniae and Cortex Magnoliae did not effect the contractions evoked by acetylcholine and histamine.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.621-639
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• 2011

The purpose of this paper is to introduce a general iterative process by viscosity approximation method with parallel method to ap-proximate a common element of the set of solutions of a mixed equilibrium problem and of the set of common fixed points of a finite family of $k_i$-strict pseudo-contractions in a Hilbert space. We obtain a strong convergence theorem of the proposed iterative method for a finite family of $k_i$-strict pseudo-contractions to the unique solution of variational inequality which is the optimality condition for a minimization problem under some mild conditions imposed on parameters. The results obtained in this paper improve and extend the corresponding results announced by Liu (2009), Plubtieng-Panpaeng (2007), Takahashi-Takahashi (2007), Peng et al. (2009) and some well-known results in the literature.

• The Journal of Korean Physical Therapy
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• v.22 no.2
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• pp.39-46
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• 2010

Purpose: This study was designed to determine whether General Coordinative Manipulation (GCM) Intervention Models have effects on the balanced restoration of asymmetrical muscles in the extremities. Methods: Fifty-nine healthy subjects (1st hypothesis: n=40, 2nd hypothesis: n=19) participated in studies using the two GCM intervention models. Subjects were studied 2 times a week for 3 weeks. Electromyography (EMG) was used to measure muscle activity, and measurements were performed before and after the application of the each intervention model. Results: Hypothesis 1: GCM Intervention, which coordinates flexion types of muscle contractions of the upper extremity and extension types of muscle contractions of the lower extremity (excluding self-care) is effective for treating shows the treatment in efficiency on more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 3 types of 4 body types (Vastus medialis, Gastrocnemius medial of Body type III, p<0.05). GCM body type was classified by the relative tilting of right and left scapulars and iliums into four groups. Hypothesis 2: GCM Intervention, which coordinates flexion types of muscle contractions of the lower extremity and extension types of muscle contractions of the upper extremity (excluding self-care) is effective for treating more than two 2 of 3 muscles (vastus medialis, gastrocnemius medial, and deltoid middle) and the effects affects on more than 2 types of 3 body types (p>0.05).

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.14 no.1
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• pp.31-38
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• 2008

Purpose : The purpose of this study was to compare the effectiveness of both neuromuscular electrical stimulation(NMES) and isometrical exercise(IE) to strengthen the quadriceps femoris muscle. The relationships between the strength changes and the relative force and duration of training contractions were also studied. Methods : The subjects were divided into three group. The control group(n=6) received no exercise and/or stimulation. The isometric exercise (IE) group(n=6) performed maximum isometric contractions, and the neuromuscular electrical stimulation(NMES)(n=6) engaged electrically stimulated isometric contractions, three days a week for four weeks. Results : Results showed that both IE group and NMES group were found to have an increase in strength significantly greater(p<0.05) than the control group at 4 week. But between IE group and NMES group were not found to have an difference in strength significantly. Conclusion : The relative increase in isometric strength, using IE and NMES, may be determined by the ability of the subjects to tolerate longer and more forceful contractions. Suggestions for further research and implications for the clinical of IE and NMES for strength-training are discussed.