• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.11a
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• pp.41-46
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• 1997

Lower esophageal sphincter (LES) is characterized by the ability to maintain a sustained pressure, and to relax allowing the passage of a bolus, whereas the esophagus is normally relaxed and contracts only briefly when required to produce peristalsis (fig. 1). The neuromuscular mechanisms that participate in the physiological regulation of these functions are not well understood, but it is thought that LES tone is spontaneous and regulated mostly through myogenic mechanisms, whereas LES relaxation and esophageal contraction are induced by neural mechanisms. Gastroesophageal reflux represents the effortless movement of gastric contents from stomach to esophagus. Because this phenomenon occurs in virtually everyone multiple times every day and in the majority of people without clinical consequences, the reflux per se is not disease. However in some cases, it can be pathologic, producing symptoms and signs called gastroesophageal reflux disease (GERD), which mechanism is not well known. It may result in heart burn, chronic esophagitis, aspiration pneumonia, esophageal strictures, and Barrett's esophagus.

• Korean Journal of Microbiology
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• v.12 no.1
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• pp.37-51
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• 1974

Three strains which accumulated large quantities of L-hlutamic acid as the chief product of metabolism in the presence of glucose and inorhanic ammonium salt under the aerobic condition sere newly isolated. These strains have the general characters as follows: Gram-positive, short fod-shaped, non-sporulating, non-motile, and facultative anaerobe. A change of cell shates was not almost observed in their life cycles and neither a phenomenon of cell-elongation nor a pleomorphism was recognized in any cases. Together with rigid stability in Gram-stain, these characters as above indicated evidences that newly isolates would belong to genus Brevibacterium clearly differentiated from genus Corynebacterium. At the same time the newly isolates, in addition to nutritional requirement of biotin and thiamine, showed the distinctive character of requirement of special amino acid such as histidine or cysteine for their considerable growth. These physiological characters including nitrates reduction, reaction on milk, and slow formation of acid from sugar also were useful in confirming that these bacteria would be Brevibacterium ammoniagenes.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.3
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• pp.37-47
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• 1997

Human observers perceive a contour where no line or edge is given (subject contour), such as the border between gratings of thin lines offset by half a cycle. Subjective contours occur in a wide variety of circumstances in nature. A common factor in all such figures in the perception of a surface(contour) occuluding part of a background, i.e. subject contours are always accompanied by subject surfaces. Some examples about these kinds of figures are given by kanizsa trangle or square. Ph;ysiological observations are reported in which the perceptual phenomenon that some simple examples of subject contours are perceived as images (gigures; contours) through physiological experiments was investgated. In this paper, we proposed a neural network extracting the induce dstimuli for the perception of subject contours based on the visual mechnism. This visual mechnism is proposed by hubel & wiesel's paper.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7431-7434
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• 2015

As an important component of innate immune system, neutrophil has been involved in many other physiological processes, including tumor-related diseases. In 2004, the phenomenon of NETs was reported for the first time. Extracellular decondensed chromatin, released from activated neutrophils, forms a network structure, which is NETs. This review focuses on the function of NETs in tumor cell proliferation, metastasis, and tumor-associated thrombosis; it also explores the application of NETs specific markers in the diagnosis of pre-thrombotic state and tumor associated diseases; it also explores NETs inhibitor for the treatment of tumor-related diseases. In view of the rapid development of NETs, it may provide new therapeutic targets for tumor-associated thrombosis, and even tumor itself.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.367-371
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• 1996

Most Koreans agree that Korean traditional singing voice has a very peculiar sound comparing to Western singing voice. The goal of this paper is to investigate the acoustic characteristics of Korean traditional singing voice called 'Pansori' Materials are analyzed from 3male professional singers and 4 female professional singers. Their singing was compared with their own conversation and other non-singers' conversation. Long term average spectra indicated that all the singers showed a much less spectral tilt than non-singers. The phenomenon was prevailing for professional singers not only in their singing, but also in their conversation. This suggests that it is not the result of a temporary effort but it may involve a certain permanent change in their physiological configuration. (To assess this hypothesis, voice source should be looked at directly. Therefore, in further research, using Rothenberg mask (Rothenberg, 1973) is strongly recommended.) In addition to LTA, individual vowel formants will be studied later.

• Phonetics and Speech Sciences
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• v.1 no.1
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• pp.9-22
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• 2009

This paper first presents the author's personal view on the importance of modeling in scientific research in general, and then describes two of his works toward modeling certain aspects of human speech communication. The first work is concerned with the physiological and physical mechanisms of controlling the voice fundamental frequency of speech, which is an important parameter for expressing information on tone, accent, and intonation. The second work is concerned with the cognitive processes involved in a discrimination test of speech stimuli, which gives rise to the phenomenon of so-called categorical perception. They are meant to illustrate the power of models based on deep understanding and precise formulation of the functions of the mechanisms/processes that underlie observed phenomena. Finally, it also presents the author's view on some models that are yet to be developed.

• 전기의세계
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• v.21 no.5
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• pp.7-12
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• 1972

Applying the theory of physiology and control systems, the visual system was studied as a regulator of impining light. The characteristics function of visual system is mainly analysed by spato-temporal characteristics based upon Enroth's model, Broca-Sulzer phenomenon and Mach effect. Some aims of this paper are as follows. (1) In order to get the excitatory and inhibitory potential of the intermediated cell layer in the retina, the exponential value, {exp(FM/kT)- $I_{mn}$ } is caculated based on the physiological theory in neuro-phenomena. (2) To show the visual characteristics by analog simulation for generating stimulus waveforms and analysis, the visual adaptation was recorded as electrical stimulation in the form of step functions. Furthermore, ti is shown that the above experimental data agrees satisfactorily with the theoretical (psychophysiological) values. This study is expected to lead to further studies concerned with human observer and human operator in control and especially pattern recognition systems.stems.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.199-204
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• 2001

In order to understand the phenomenon in a living cell correctly, it has been required to obtain intact responses from the cell membrane without disrupting the cytoplasmic circumstances. Gramicidin perforated patch configuration allows the electrical access to the whole cell with a minimal dialysis of cytoplasm and preventing the loss of native intracellular constituents, such as $Cl^-.$ Here, we would like to show the background of this method and the actual application of the gramicidin perforated patch recording mode on the dissociated neurons.

• Molecules and Cells
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• v.45 no.10
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• pp.685-691
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• 2022

Early-life environmental factors can have persistent effects on physiological functions by altering developmental procedures in various organisms. Recent experimental and epidemiological studies now further support the idea that developmental programming is also present in mammals, including humans, influencing long-term health. Although the mechanism of programming is still largely under investigation, the role of endocrine glucocorticoids in developmental programming is gaining interest. Studies found that perinatal glucocorticoids have a persistent effect on multiple functions of the body, including metabolic, behavioral, and immune functions, in adulthood. Several mechanisms have been proposed to play a role in long-term programming. In this review, recent findings on this topic are summarized and the potential biological rationale behind this phenomenon is discussed.

• The Journal of Korean Medical History
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• v.19 no.2
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• pp.101-118
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• 2006

Phenomena experienced by all individuals and cultural interpretation of such phenomena seem to be irrelevant to the change of time. The subject dream to be discussed in this study is one of them. Nevertheless, people's attitude of understanding dreams in the past is obviously different from the contemporary one, and the interpretation of dreams reveals the science of the corresponding age. Bishop Daveluy, a missionary to Chosun in the mid 19th century, observed Korean people's hardly understandable response to dreams. According to his explanation, Chosun people regarded what they saw in a dream as a fact. It might have been quite long that a dream is regarded as a sign of the future. However, how a dream can be a sign of the future is explained different according to the science of the corresponding age. Many records on dreams since the late Koryo Dynasty and the early Chosun Dynasty did not give satisfactory answers to this question. However, new interpretations of dreams were attempted occasionally in the process that the Sung Confucian view of nature in the Chosun Dynasty was being matured. One of such interpretations is that a dream is obviously a phenomenon of human cognition and there is a rule behind dreams. I t was believed that the rule is a flow of energy defined by reason penetrating through the past, the present and the future and, as a consequence, dreams are future oriented. The view that a dream is a phenomenon with a causal relation is observed more specifically in medicine. I t was understood basically as a pathological phenomenon but, at the same time, a substance in an organic relation with the human body. In addition, it was understood as the results of facts (physiological and pathological processes) experienced by the body in the past and the sign of diseases in the future. However, from the viewpoint of contemporary science based on empirical rationalism, such foreseeability is fundamentally unacceptable. In contemporary science, in which scientific analysis of phenomena has to be of the past tense, dreams exist as the representations of the past. What Bishop Daveluy saw in Korean people was a phenomenon observed when the pre modern met the modern as pre modern people's life and idea were viewed from a modern people's eye.