• Title/Summary/Keyword: Central mechanism

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Analysis of Injury Mechanism on Ankle and Knee during Drop Landings According to Landing Directions (드롭랜딩 시 착지 방향에 따른 발목과 무릎 상해 기전 분석)

  • Cho, Joon-Haeng;Kim, Kyoung-Hun;Moon, Gon-Sung;Cho, Young-Jae;Lee, Sung-Cheol
    • Korean Journal of Applied Biomechanics
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    • v.20 no.1
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    • pp.67-73
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    • 2010
  • The purpose of this study was to compare the differences in kinematic and kinetic parameters of the ankle and knee joint according to three landing direction(central, left, right). Fifteen collegiate male athletes(age: $22.7{\pm}3.5$ years, height: $174.9{\pm}7.1\;cm$, weight: $69.4{\pm}6.7\;kg$) with the right leg as dominant were chosen. The subjects performed series of drop landings in three directions. In terms of the three different landing directions, plantar flexion was the greatest during the central drop landings. For each initial contact of the landing direction, plantar flexion of the ankle was greatest at the central drop landing, inversion of the ankle was greatest at the right landing and valgus of the knee was greatest at the left drop landing. Regarding the peak force, the greatest was at the 1st peak force during the central drop landing. For the time-span of the 2nd peak force and the 2-1 peak force, both right sides resulted as the greatest. Therefore, with the appropriate training in landing techniques and developing neuromuscular training for proprioception by taking the injury mechanisms on ankle and knee during drop landings into account, it will assist in preventing such injuries.

Inhibition of Wnt/β-catenin signaling by monensin in cervical cancer

  • Bingbing Fu;Lixia Fang;Ranran Wang;Xueling Zhang
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.1
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    • pp.21-30
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    • 2024
  • The challenging clinical outcomes associated with advanced cervical cancer underscore the need for a novel therapeutic approach. Monensin, a polyether antibiotic, has recently emerged as a promising candidate with anti-cancer properties. In line with these ongoing efforts, our study presents compelling evidence of monensin's potent efficacy in cervical cancer. Monensin exerts a pronounced inhibitory impact on proliferation and anchorage-independent growth. Additionally, monensin significantly inhibited cervical cancer growth in vivo without causing any discernible toxicity in mice. Mechanism studies show that monensin's anti-cervical cancer activity can be attributed to its capacity to inhibit the Wnt/β-catenin pathway, rather than inducing oxidative stress. Monensin effectively reduces both the levels and activity of β-catenin, and we identify Akt, rather than CK1, as the key player involved in monensin-mediated Wnt/β-catenin inhibition. Rescue studies using Wnt activator and β-catenin-overexpressing cells confirmed that β-catenin inhibition is the mechanism of monensin's action. As expected, cervical cancer cells exhibiting heightened Wnt/β-catenin activity display increased sensitivity to monensin treatment. In conclusion, our findings provide pre-clinical evidence that supports further exploration of monensin's potential for repurposing in cervical cancer therapy, particularly for patients exhibiting aberrant Wnt/β-catenin activation.

Insulin secretory activity and mechanism of compound K

  • Choi, Yun-Suk;Han, Gi-Cheol;Sung, Jong-Hwan;Chung, Sung-Hyun
    • Proceedings of the Ginseng society Conference
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    • 2006.05a
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    • pp.69-70
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    • 2006
  • Purpose: Panaxadiols are more potent than panaxatriols as far as insulin secretory activity is concerned. In this study, we examined insulin secretory activity and mechanism of compound K (CK), a major intestinal bacterial metabolite of ginsenosides. Method: Insulin secretory activity of CK was examined using pancreatic beta cells and in Oral Glucose Tolerance Test assay. In addition, insulin secretory mechanism was studied in terms of calcium dependent or independent pathways. Results: In vitro, CK enhanced the insulin secretion concentration-dependently when compared to glucose-stimulated control cells. Insulin secretory mechanism of CK seems to block ATP sensitive K channels, which was confirmed by diazoxide (K channel opener) but, insulin resistance ameliorating activity of CK can't be ruled out. In vivo, CK showed hypoglycemic effect in OGTT.

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Reliable Distributed Lookup Service Scheme for Mobile Ad-hoc Networks

  • Malik Muhammad Ali;Kim Jai-Hoon
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06d
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    • pp.124-126
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    • 2006
  • Mobile Ad hoc networking is an emerging technology and in these days many applications are being developed to run on these networks. In these networks lookup services are very important because all nodes do not have same resources in term of memory and computing power. Nodes need to use different services offered by different servers. Reliable and efficient scheme should be available for lookup services due to limited bandwidth and low computing power of devices in mobile ad hoc networks. Due to mobility and rapid change in network topology, lookup mechanism used in wired network is not appropriate. Service discovery mechanism can be divided into two main categories Centralized and Distributed. Centralized mechanism is not reliable as there is no central node in these networks. Secondly centralized mechanism leads toward single point failure. We can handle the service discovery mechanism by distributing server's information to each node. But this approach is also not appropriate due to limited bandwidth and rapid change in network. In this paper, we present reliable lookup service scheme which is based on distributed mechanism. We are not using replication approach as well due to low bandwidth of wireless networks. In this scheme service discovery mechanism will be handled through different lookup servers. Reliability is the key feature of our proposed scheme.

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Clinical, Neuroimaging and Neurophysiologic Evidences of Restless Legs Syndrome as a Disorder of Central Nervous System (하지불안증후군이 중추신경계 질환임을 시사하는 임상적, 신경영상학적, 신경생리학적 증거들에 관하여)

  • Jung, Ki-Young
    • Annals of Clinical Neurophysiology
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    • v.10 no.2
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    • pp.98-100
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    • 2008
  • Restless legs syndrome (RLS) is a sensorimotor neurological disorder in which the primary symptom is a compelling urge to move the legs, accompanied by unpleasant and disturbing sensations in the legs. Although pathophysiologic mechanism of RLS is still unclear, several evidences suggest that RLS is related to dysfunction in central nervous system involving brain and spinal cord. L-DOPA, as the precursor of dopamine, as well as dopamine agonists, plays an essential role in the treatment of RLS leading to the assumption of a key role of dopamine function in the pathophysiology of RLS. Patients with RLS have lower levels of dopamine in the substantia nigra and respond to iron administration. Iron, as a cofactor in dopamine production, plays a central role in the etiology of RLS. Functional neuroimaging studies using PET and SPECT support a central striatal D2 receptor abnormality in the pathophysiology of RLS. Functional MRI suggested a central generator of periodic limb movements during sleep (PLMs) in RLS. However, to date, we have no direct evidence of pathogenic mechanisms of RLS.

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Anti-inflammatory and Anticancer Activities of Ethanol Extract of Pendulous Monkshood Root in vitro

  • Huang, Xian-Ju;Ren, Wei;Li, Jun;Chen, Lv-Yi;Mei, Zhi-Nan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3569-3573
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    • 2013
  • Aim: Pendulous monkshood root is traditionally used for the treatment of several inflammatory pathologies such as rheumatisms, wounds, pain and tumors in China. In this study, the anti-inflammatory and anticancer activities and the mechanism of crude ethanol extract of pendulous monkshood root (EPMR) were evaluated and investigated in vitro. Materials and Methods: The cytotoxic effects of EPMR on different tumor cell lines were determined by the MTT method. Cell apoptosis and cell nucleus morphology were assessed by Hoechst 33258 staining. Moreover, nitric oxide (NO) levels and intracellular oxidative stress in peritoneal macrophages were determined to further elucidate mechanisms of action. Results: The data showed that EPMR could produce significant dose-dependent toxicity on three kinds of tumor cells. Furthermore, EPMR displayed obvious anti-inflammatory effects on LPS-induced mouse peritoneal macrophages at the dosage of 4 - 200 ${\mu}g/mL$. The results demonstrated the therapeutic potential of Pendulous Monkshood Root on cancer and inflammatory diseases. Conclusion: Our results indicate that EPMR has anti-inflammatory and anticancer properties, suggesting that pendulous monkshood root may be a useful anti-tumor and anti-inflammatory reagent in the clinic.

Influence of water content on dynamic mechanical properties of coal

  • Gu, Helong;Tao, Ming;Wang, Jingxiao;Jiang, Haibo;Li, Qiyue;Wang, Wen
    • Geomechanics and Engineering
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    • v.16 no.1
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    • pp.85-95
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    • 2018
  • Water affects the mechanical properties of coal and stress wave propagation. To comprehensively investigate the effect of water content on the properties of coal, laboratory tests including X-Ray Diffraction (XRD) analysis, P-wave test, S-wave test, static and dynamic compression test with different water contents were conducted. The compressive strength, elastic modulus and failure strain and their mechanism of coal specimen under coupled static-dynamic load with the increased water content were observed. Meanwhile, energy transmission and dissipation characteristics of a stress wave in coal specimens with different water contents under dynamic load and its relation with the failure features, such as fragmentation and fractal dimension, of coal was analyzed. Furthermore, the dynamic interpretation of water infusion to prevent coal burst based on water infusion model of coal seam roadway was provided.

Immunomodulating Activity of DW-116, A New Quinolone Antibiotic

  • Moon, Eun-Yi;Choi, Chung-Ha;Pyo, Suh-Kneung;Chung, Yong-Ho;Yoon, Sung-June;Lee, Dug-Keun
    • Archives of Pharmacal Research
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    • v.21 no.5
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    • pp.610-614
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    • 1998
  • DW-116, [1-(5-fluoro-2-pyridyl)-6-fluoro-7-(4-methyl-1-piperazinyl)-1,4-dihydro-4-oxoquino-line-3-carboxylic acid hydrochloride}, is a new quinolone antibiotic with a broad antibacterial spectrum against G(+) and G(-) bacteria. DW-116 was evaluated for the immunomodulating activities, which is one of the efforts to investigate the mechanism of action related to the good in vivo antibacterial efficacy. The results of in vitro studies revealed there was no statistically significant increase in B and T lymphocyte proliferation. But the results of in vivo studies showed that the number of plaque forming cells (PFC), the amount of polyclonal antibodies and delayed-type hypersensitivity (DTH) were significantly increased after the repeat administration with 12 and 60 mg/kg of DW-116. Taken together, these results proposed that immunostimulting effect of DW-116 could be one of the action mechanisms for demonstrating in vivo antibacterial activities under these experimental conditions.

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The Central Place Analysis with the Characteristics of the Distribution of the Land Price Using GIS (GIS를 이용한 지가분포특성에 따른 중심지분석)

  • Jung, Dae-Young;Kim, Sang-Soo;Kim, Kye-Hyun
    • Journal of Korean Society for Geospatial Information Science
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    • v.17 no.3
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    • pp.65-70
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    • 2009
  • To manage the urban land systematically, it is necessary to analyze the land price annually and correct the problems found by the annual land price analysis. The characteristics of the distribution of the land price and the grip of the central place using GIS can be used as the useful fundamental data for the urban planning and its management mechanism. In this study, the central place measurement, the distribution map and the isarithmic map is analyzed based on the individual notification land price and also its relationship with the central place is analyzed in case study area, Daejeon city.

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Behavior of headed shear stud connectors subjected to cyclic loading

  • Ding, Fa-xing;Yin, Guo-an;Wang, Hai-bo;Wang, Liping;Guo, Qiang
    • Steel and Composite Structures
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    • v.25 no.6
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    • pp.705-716
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    • 2017
  • The objective of this study is to investigate the actual behavior of studs in structures under earthquake load through laboratory tests and numerical simulation. A test program including eighteen specimens was devised with consideration of different concrete strengths and stud diameters. Six of specimens were subjected to monotonically increasing loading while the others were subjected to cyclic loading. Mechanical behavior including the failure mechanism, load-slip relationship, stiffness degradation, energy dissipation and the damage accumulation was obtained from the test results. An accurate numerical model based on the ABAQUS software was developed and validated against the test results. The results obtained from the finite element (FE) model matched well with the experimental results. Furthermore, based on the experimental and numerical data, the design formulas for expressing the skeleton curve were proposed and the simplified hysteretic model of load versus displacement was then established. It is demonstrated that the proposed formulas and simplified hysteretic model have a good match with the test results.