• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.614-623
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• 2016

Grid(pipe network) design is an important element of Smart Water Grid, which essential to estimate hydraulic parameters such as the pressure, friction factor, friction velocity, head loss and energy slope. Especially, friction velocity in a grid is an important factor in conjunction with energy gradient, friction coefficient, pressure and head loss. However, accurate estimation friction head loss, friction velocity and friction factor are very difficult. The empirical friction factor is still estimated by using theory and equation which were developed one hundred years ago. Therefore, in this paper, new equation from maximum velocity and friction velocity is developed by using integration relationship between Darcy-Weisbach's friction head loss equation and Schlichting equation and regression analysis. To prove the developed equation, smooth pipe data areis used. Proposed equation shows high accuracy compared to observed data. Study results are expected to be used in stability improvements and design in a grid.

• The Korea Journal of Herbology
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• v.30 no.3
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• pp.55-61
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• 2015

Objectives : This study aimed to investigate the effects of Shingi-whan(SG) on the male reproductive and sexual function, so we measured the spermatogenesis and the testicular toxicity in mice and the vasorelaxation in isolated rabbit corpus cavernosum smooth muscle. Methods : To evaluate effect on the spermatogenesis in mice, we prepared two groups, control group and SG group that was orally administered SG(1,000mg/kg) for 20 days, and compared. To analyze testicular toxicity in mice, we also prepared two groups, doxo group that was injected with doxorubicin (3mg/kg) on three times and doxo + SG group that was injected with doxorubicin and SG for 20 days, and compared. To investigate sexual function of SG in mice, we prepared three groups, normal group and aging elicited group consisting of 18-month-old mice, SG treated aging group that was orally administered SG for 60 days, and compared using histochemical staining on mice corpus cavernous tissues. In order to define the relaxation effects of SG, rabbit corpus cavernous tissues were prepared in $2{\times}2{\times}6mm$ sized strip. Then the dose-dependent relaxation responses of SG at 0.01-3.0 mg/ml in contracted strips induced by phenylephrine were measured. Results : The sperm density in dutus epididymis and the diameter of seminiferous tubules of SG group was significantly increased when compared to control group. The testicular weight and the diameter and height of epithelial layer of seminiferous tubules of doxo + SG group was significantly increased when compared to doxo group. The cavernous strips were significantly relaxed by SG extract In SG treated aging group, ratio of smooth muscles to collagen fibers and red blood cell count in venous sinus was increased as compared to aging elicited group. Conclusions : Our findings have shown that SG extract have effect on spermatogenesis and mitigating effect on doxo-induced testicular toxicity. Further, it also have the vasorelaxant effect on rabbit corpus cavernosum.

• BMB Reports
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• v.53 no.4
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• pp.206-211
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• 2020

Vascular smooth muscle cells (VSMCs) are a unique cell type that has unusual plasticity controlled by environmental stimuli. As an abnormal increase of VSMC proliferation is associated with various vascular diseases, tight regulation of VSMC phenotypes is essential for maintaining vascular homeostasis. Hypoxia is one environmental stress that stimulates VSMC proliferation. Emerging evidence has indicated that microRNAs (miRNAs) are critical regulators in the hypoxic responses of VSMCs. Therefore, we previously investigated miRNAs modulated by hypoxia in VSMCs and found that miR-1260b is one of the most upregulated miRNAs under hypoxia. However, the mechanism that underlies the regulation of VSMCs via miR-1260b in response to hypoxia has not been explored. Here we demonstrated that hypoxia-induced miR-1260b promotes VSMC proliferation. We also identified growth differentiation factor 11 (GDF11), a member of the TGF-β superfamily, as a novel target of miR-1260b. miR-1260b directly targets the 3'UTR of GDF11. Downregulation of GDF11 inhibited Smad signaling and consequently enhanced the proliferation of VSMCs. Our findings suggest that miR-1260b-mediated GDF11-Smad-dependent signaling is an essential regulatory mechanism in the proliferation of VSMCs, and this axis is modulated by hypoxia to promote abnormal VSMC proliferation. Therefore, our study unveils a novel function of miR-1260b in the pathological proliferation of VSMCs under hypoxia.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.17-26
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• 1991

Single smooth muscle cells of the rabbit pulmonary artery were isolated by treatment with collagenase and elastase. Using the patch clamp technique, potassium channel activity was recorded from the inside-out membrane patch. The channel had a sin히e channel conductance of about 360 pS in symmetrical concentration of K on both sides of the patch, 150 mM, and had a linear current-voltage relationship. During the application of 10 mM tetraethylammonium (TEA) to the intracellular membrane surface, the amplitude of single channel current was reduced and very rapid flickering appeared. The open probability $(P_0)$ of this channel was increased by increasing positivity of the potential across the patch membrane, with e-fold increase by 20 mV depolarization, and by increasing the internal $Ca^{2+}$ concentration. These findings are consistent with those of large conductance Ca-activated K channels reported in other tissues. But the shortening of the mean open time by increasing $[Ca^{2+}]_i$, was an unexpected result and one additional closed state which might be arisen from a block of the open channel by Ca binding was suggested. The $P_0-membrane$ potential relationship was modulated by internal pH. Decreasing pH reduced $P_0$. Increasing pH not only increased $P_0$ but also weakened the voltage dependency of the channel opening. The modulation of Ca-activated K channel by pH was thought to be related to the mechanism of regulation of vascular tone by the pH change.

• Journal of Korean society of Dental Hygiene
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• v.18 no.5
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• pp.843-852
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• 2018

Objectives: The study aimed to isolate the abundant bacteria in dental caries in children and to investigate the bacterial species involved in addition to those that have been previously reported. Methods: The specimens were collected from the supragingival plaques of each dental caries area, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, and from healthy subjects in the control group. Bacteria were cultured from these specimens, DNA was extracted from the isolated bacteria, and the 16S rRNA gene sequences were analyzed and identified. Results: Based on the results of the 16S rRNA gene sequence analysis for the 90 strains of dominant bacteria from the 45 specimens, 5, 7, 8, 7, and 13 species were identified from the supragingival plaques from healthy teeth, pit and fissure caries, deep dentinal caries, smooth surface caries, and dental caries, respectively. In healthy teeth, Actinomyces naeslundii dominated. Corynebacterium durum, Ralstonia pickettii, and Streptococcus intermedius showed equal distribution. The dominant bacterial species in dental caries, S. sanguinis, showed the greatest difference in prevalence in pit and fissure caries. In deep dentinal caries, S. mutans and Lactobacillus rhamnosus were dominant; in smooth surface caries, S. mutans and S. sanguinis were dominant; and in the supragingival plaques of dental caries, S. sanguinis and S. mutans were dominant. Conclusions: The bacterial species isolated from dental caries encompassed four phyla, eight genera, and 22 species. In addition, the SS1-2 strain, belonging to the genus Neisseria, was identified as a new species from among the isolated strains.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.479-486
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• 2000

The aim of this study was to clarify the mechanism of the inhibitory action of carbon monoxide (CO) on contraction, by measuring cytosolic $Ca^{2+}$ level $([Ca^{2+}]_i)$ and ionic currents in guinea-pig ileum. CO (10%) inhibited 40 mM KCl-induced contraction and this effect was blocked by ODQ $(1\;{\mu}M),$ a soluble guanylyl cyclase (sGC) inhibitor. CO inhibited the 40 mM KCl-induced contraction without changing $[Ca^{2+}]_i.$ Cumulative addition of KCl induced a graded increase in $[Ca^{2+}]_i$ and muscle tension. In the presence of CO, cumulative addition of KCl induced smaller contraction than in the absence of CO. On the other hand, the increase in $[Ca^{2+}]_i$ induced by cumulative addition of KCl was only slightly decreased in the presence of CO, and the $[Ca^{2+}]_i-tension$ relationship shifted downwards. Using the patch clamp technique with a holding potential of -60 mV, we found that CO had little effect on the peak Ba currents $(I_{Ba})$ when voltage was stepped from -60 mV to 0 mV. In addition, CO showed no effect on the depolarization-activated outward $K^+$ currents in the all potential ranges. We conclude that CO inhibits smooth muscle contraction mainly by decreasing the $Ca^{2+}$ sensitivity of contractile elements via a cGMP-dependent pathway, not by involving L-type $Ca^{2+}$ and outward-potassium currents in guinea-pig ileum.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.2
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• pp.113-120
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• 2000

To investigate the mechanism of smooth muscle contraction induced by emptying of intracellular $Ca^{2+}$ stores, we measured isometric contraction and $^{45}Ca^{2+}$ influx. $CaCl_2$ increased $Ca^{2+}$ store emptying- induced contraction in dose-dependent manner, but phospholipase C activity was not affected by the $Ca^{2+}$ store emptying-induced contraction. The contraction was inhibited by voltage-dependent $Ca^{2+}$ channel antagonists dose dependently, but not by TMB-8 (intracellular $Ca^{2+}$ release blocker). Both PKC inhibitors (H-7 and staurosporine) and tyrosine kinase inhibitors (genistein and methyl 2,5-dihydroxycinnamic acid) significantly inhibited the contraction, but calmodulin antagonists (W-7 and trifluoperazine) had no inhibitory effect on the contraction. The combined inhibitory effects of protein kinase inhibitors, H-7 and genistein, together with verapamil were greater than that of each one alone. In $Ca^{2+}$ store-emptied condition, $^{45}Ca^{2+}$ influx was significantly inhibited by verapamil, H-7 or genistein but not by trifluoperazine. However combined inhibitory effects of protein kinase inhibitors, H-7 and genistein, together with verapamil were not observed. Therefore, this kinase pathway may modulate the sensitivity of contractile protein. These results suggest that contraction induced by emptying of intracellular $Ca^{2+}$ stores was mediated by influx of extracellular $Ca^{2+}$ through voltage-dependent $Ca^{2+}$ channel, also protein kinase C and/or tyrosine kinase pathway modulates the $Ca^{2+}$ sensitivity of contractile protein.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.311-316
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• 2010

It is well-known that electrical field stimulation (EFS)-induced contraction is mediated by a cholinergic mechanism and other neurotransmitters. NO, ATP, calcitonin gene-related peptide (CGRP), and substance P are released by EFS. To investigate the purinergic mechanism involved in the EFS-induced contraction, purinegic receptors antagonists were used. Suramine, a non-selective P2 receptor antagonist, reduced the contraction induced by EFS. NF023 ($10^{-7}{\sim}10^{-4}M$), a selective P2X antagonist, inhibited the contraction evoked by EFS. Reactive blue ($10^{-6}{\sim}10^{-4}M$), selective P2Y antagonist, also blocked the contraction in a dose-dependent manner. In addition, P2X agonist ${\alpha}$,${\beta}$-methylene 5'-adenosine triphosphate (${\alpha}{\beta}MeATP$, $10^{-7}{\sim}10^{-5}M$) potentiated EFS-induced contraction in a dose-dependent manner. P2Y agonist adenosine 5'-[${\beta}$-thio]diphosphate trilithium salt ($ADP{\beta}S$, $10^{-7}{\sim}10^{-5}M$) also potentiated EFS-induced contractions in a dose-dependent manner. Ecto-ATPase activator apyrase (5 and 10 U/ml) reduced EFS-induced contractions. Inversely, 6-N,$N$-diethyl-D-${\beta}$,${\gamma}$- dibromomethylene 5'-triphosphate triammonium (ARL 67156, $10^{-4}M$) increased EFS-induced contraction. These data suggest that endogenous ATP plays a role in EFS-induced contractions which are mediated through both P2X-receptors and P2Y-receptors stimulation in cat esophageal smooth muscle.

• The Journal of Internal Korean Medicine
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• v.27 no.2
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• pp.295-304
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• 2006

Objectives : This study was done to investigate whether two oriental prescriptions, saganmahwang-tang (SMT) and prescription C (P-C) significantly affect mucin release from cultured hamster tracheal surface epithelial (HTSE) cells. Methods : Cofluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of SMT or P-C to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase (LDH) release. Also, the effects of SMT and P-C on contractility of isolated tracheal smooth muscle were investigated. Results : SMT significantly inhibited mucin release from cultured HTSE cells, without cytotoxicity. P-C significantly increased mucin release from cultured HTSE cells, with significant cytotoxicity. SMT inhibited Ach-induced contraction of isolated tracheal smooth muscle. P-C did not affect Ach-induced contraction of isolated tracheal smooth muscle. Conclusion : Results su99est that SMT and P-C have regulating effects on mucin secretion from airway goblet cells. Further investigation is needed, because of the value in finding novel agents to this purpose, and these oriental medical prescription have potential for such a role.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.461-466
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• 2003

The primary mechanism of smooth muscle contraction is phosphorylation of the 20 kDa myosin light chains(LC20) by a myosin light chain kinase(MLCK). Relaxation, then, is generally the result of dephosphorylation of LC20 by myosin phosphatase(MP). Changes in MP activity is one of the important mechanisms in the regulation of Ca2+-sensitivity. Inhibition of MP activity is linked to an increase in phosphorylated myosin light chain(MLC) without an increase in [Ca/sup 2+/]i-levels. It is now generally accepted that Rho-kinase phosphorylates 130 kDa regulatory and myosin binding subunits(M130, MYPT) of MP, which results in an inhibition of MP activity. In addition Rho-kinase can also directly phosphorylate MLC. In the present study, LC20 phosphorylation and MP subunits translocation to the cell membrane were investigated in freshly isolated ferret portal vein smooth muscle single cells treated with PGF2α. We also examined the effect of Y27632(10-5mol/L), Rho-kinase inhibitor, in the MP subunits localization to compare with butanol fraction of Fructus Crataegi in its effect. Butanol fraction of Fructus Crataegi(BFFC; 1㎎/㎖) was more effective in PGF2α induced contraction than those of phenylephrine in its vasodilation effect. It significantly(P<0.05) dephosphorylated the LC20 at time indicated. In addition, the dissociation of subunits are inhibited by BFCF treatment. The results indicate that, in the smooth muscle cells, the relaxation effect of BFFC is associated with increase of MP activity based on inhibition of dissociation of the catalytic and targeting subunits of the phosphatase, and thus decrease the sensitivity of LC20 phosphorylation for Ca/sup 2+/.