• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.83-87
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• 2008

Tension wood, a specialized tissue developed in the upper side of the leaning stem and drooping branches of angiosperm, is an attractive experimental system attractive for exploring the development and the biochemical pathways of the secondary cell wall formation, as well as the control mechanism of the carbon flux into lignin, cellulose, and hemicellulose. However, the mechanism underlying the induction and the development of the tension wood is largely unknown. Recently, several researchers suggested the possible roles of the plant growth hormones including auxin, gibberellin, and ethylene mainly based on the expression pattern of the genes in this specialized tissue. In addition, expressed sequence tag of Poplar and Eucalyptus provide global view of the genetic control underlying the tension wood formation. However, the roles of the majority of the identified genes have not yet been clearly elucidated. The present review summarized current knowledge on the biosynthesis of tension wood to provide a brief synopsis of the molecular mechanism underlying the development of the tension wood.

• Korean System Dynamics Review
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• v.7 no.2
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• pp.5-20
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• 2006

In the advent of ubiquitous information technology (u-IT) as a new emerging horizon of information society, inflated expectations regarding u-IT are growing very fast and higher than those made in the past, which would perhaps result in serious bust after boom and incur tremendous amount of social costs. This paper thus investigates a dynamic mechanism underlying the coevolution between information technology and society by applying systems thinking, particularly, with a focus on the typical phenomenon, 'hype curve' which shows how new technologies initially grow too fast for their own good, crashing from a peak of inflated expectations into a trough of disillusionment before stabilizing on a plateau of productivity. Three basic questions are explored to answer by investigating the mechanisms underlying the 'boom-bust' phenomenon: First, why hype curve appears in the process of technology and society coevolution. Second, how to enhance the stabilization level. Third, when is the right time for the policy intervention.

• Development and Reproduction
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• v.27 no.1
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• pp.1-7
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• 2023

Small-cell lung cancer (SCLC) continues to be the deadliest of all lung cancer types. Its high mortality is largely attributed to the unchangeable development of resistance to standard chemo/radiotherapies, which have remained invariable for the past 30 years, underlining the need for new therapeutic approaches. Recent studies of SCLC genome revealed a large number of somatic alterations and identified remarkable heterogeneity of the frequent mutations except for the loss of both RB and P53 tumor suppressor genes (TSGs). Identifying the somatic alterations scattered throughout the SCLC genome will help to define the underlying mechanism of the disease and pave the way for the discovery of therapeutic vulnerabilities associated with genomic alterations. The new technique made it possible to determine the underlying mechanism for the discovery of therapeutic targets. To these ends, the techniques have been focused on understanding the molecular determinants of SCLC.

• Korean Journal of Radiology
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• v.21 no.7
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• pp.929-930
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• 2020

• Perspectives in Nursing Science
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• v.14 no.2
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• pp.64-69
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• 2017

Purpose: Breathing can be controlled either unconsciously or consciously. In Asian countries, various conscious breathing-control techniques have been practiced for many years to promote health and wellbeing. However, the exact mechanism underlying these techniques has not yet been established. The purpose of this study is to explore the physiological mechanism explaining how conscious breathing control could affect the autonomic nervous system, brain activity, and mental changes. Methods: The coupling phenomenon among breathing rhythm, heart rate variability, and brain waves was explored theoretically based on the research hypothesis and a review of the literature. Results: Respiratory sinus arrhythmia is a well-known phenomenon in which heart rate changes to become synchronized with breathing: inhalation increases heart rate and exhalation decreases it. HRV BFB training depends on conscious breathing control. During coherent sinusoidal heart rate changes, brain ${\alpha}$ waves could be enhanced. An increase in ${\alpha}$ waves was also found and the synchronicity between heart beat rhythm and brain wave became strengthened during meditation. Conclusion: In addition to the effect of emotion on breathing patterns, conscious breathing could change heart beat rhythms and brainwaves, and subsequently affect emotional status.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.179-189
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• 1987

Since it has been known that ryanodine has a potent negative inotropic effect on the cardiac muscle contractility (Jenden and Fairhurst, 1968), ryanodine has been a subject of intensive research (Frank and Sleator, 1975; Jones et al, 1978; Sutko et al, 1985). However, the underlying mechanism for the ryanodine dependent negative inotropic effect is still uncertain. In this study, the effects of ryanodine on the generation and relaxation of contracture due to Na-withdrawal and on the force-frequency relationship of heart muscles isolated from rats and guinea pigs were measured in an effort to understand the underlying mechanism of the ryanodine-induced negative inotropy. Results are summerized as follows: 1 ) Ryanodine significantly reduced the contractility of heart muscles produced at low frequency of stimulation, but showed a little effect on the contractility at high frequency stimulation. 2) Ryanodine, at the concentrations ranging from $10^{-6}\;M$ to $10^{-8}\;M$, had no significant effect on the Na-dependent relaxation of Na-withdrawl contracture. 3) Ryandoine significantly reduced the amplitude of the Na-withdrawl contracture, and this inhibitory effect was reinforced by procaine, antiagonized by caffeine and high potassium. From these results, it may be concluded that the negative inotropic effect of ryanodine is mainly due to an inhibition of calcium release from sarcoplasmic reticulum.

• Geomechanics and Engineering
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• v.8 no.2
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• pp.237-255
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• 2015

From the related engineering principles, analytical solutions for horizontal crack initiation and propagation on a coal panel floor-underlying strata interface due to coal panel excavation are derived in this paper. Two important concepts, namely the critical panel width of horizontal crack initiation on the panel floor-underlying strata interface and the critical panel width of vertical fracture (crack) initiation in the panel floor, have been presented. The resulting analytical solution indicates that: (1) the first criterion can be used to express the condition under which horizontal plane cracks (on the panel floor-underlying strata interface or in the panel floor because of delamination) due to the mining induced vertical stress will initiate and propagate; (2) the second criterion can be used to express the condition under which vertical plane cracks (in the panel floor) due to the mining induced horizontal stress will initiate and propagate; (3) this orthogonal set of horizontal and vertical plane cracks, once formed, will provide the necessary weak network for the flow of gas to inrush into the panel. Two characteristic equations are given to quantitatively estimate both the critical panel width of vertical fracture initiation in the panel floor and the critical panel width of horizontal crack initiation on the interface between the panel floor and its underlying strata. The significance of this study is to provide not only some theoretical bases for understanding the fundamental mechanism of a longwall floor gas inrush problem but also a benchmark solution for verifying any numerical methods that are used to deal with this kind of gas inrush problem.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.920-923
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• 2005

Epilepsy is a neurological disorder from many molecular and biochemical responses. In the underlying mechanism, free radicals play an important role in seizure initiation and seizure-induced brain damage. Excessive production of oxygen free radicals and other radical species have been implicated in the development of seizures under pathological conditions and linked to seizure-induced neurodegeneration.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.138-139
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• 2007

• Proceedings of the Korean Biophysical Society Conference
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• 1999.06a
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• pp.29-29
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• 1999

Diabetic cardiomyopathy has been suggested to be caused by the intracellular Ca$\^$2＋/ overload in the myocardium. We have investigated the possible mechanism of the functional defect of cardiac sarcoplasmic reticulum (SR) in diabetic rats with respect to Ca$\^$2＋/-ATPase and phospholamban (PLB) at the transcriptional and translational levels.(omitted)