• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.97-101
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• 1989

N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms.

• Journal of Dairy Science and Biotechnology
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• v.36 no.1
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• pp.14-25
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• 2018

Melatonin, an indolic tryptophan-derived compound, is secreted rhythmically from the pineal gland, mainly under the regulation of the circadian clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus. Melatonin is widely present in nature, with biological activities in unicellular organisms, plants, and animals. A major function of melatonin is to transmit information to organisms about certain physiological functions in response to daily and seasonal variations in their environment. In this paper, we review a variety of melatonin's functional properties, its occurrence in plants, and its synthesis by yeasts. Fermented milk supplemented with melatonin-rich plants and yeasts can be used for the effective treatment of sleep disorders.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1647-1652
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• 2010

Autophagy refers to the bulk degradation of cellular proteins and organelles through an autophagosome and plays a pivotal role in the development, cellular differentiation, aging, and elimination of aberrant structures. A failure of autophagy has been implicated in a growing list of mammalian disease states, including cancer and cardiomyopathy. Two ubiquitin-like systems are highly involved in autophagy, especially in the formation of autophagosomes. Here, we purified and characterized Atg7 (an E1-like enzyme), and Atg3 and Atg10 (E2-like enzymes) in order to gain an insight into the role played by ubiquitin-like systems in the formation of autophagosomes. Interestingly, we observed that Atg7 forms a homodimer to construct an active conformation, unlike other E1-like enzymes. Although Atg3 was detected as a monomer under physiological conditions, Atg10 existed in an oligomeric form, indicating that the mechanism by which Atg10 functions may differ from that of Atg3.

• Journal of Integrative Natural Science
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• v.5 no.2
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• pp.65-71
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• 2012

Neuropeptide Y (NPY), a 36-amino acid polypeptide, is a member of the pancreatic polypeptide family, which consists of NPY, peptide YY (PYY) and pancreatic polypeptide (PP). The neuropeptide Y (NPY) receptors called Y receptors belongs to G-protein coupled that are involved in a variety of physiological functions such as appetite regulation, circadian rhythm and anxiety. Five receptor subtypes have been cloned in mammals (Y1, Y2, Y4, Y5, and Y6) of which four are functional. In this short review, information about the functional NYP receptors was analyzed. Sequence analyses were done between these receptors to identify the relationships between them. Phylogram was generated between these receptors to identify the close homologue between these receptors. Our sequence analyses found that Y1 and Y4 receptors are close than the other receptors. Further structure based analysis could be useful to identify subtype selective antagonists and dual antagonists targeting Y1 and Y4 receptors.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.18-21
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• 2001

The change of sleep pattern is one of the most often altered normal physiological functions in elderly people. Besides normal change of sleep, insomnia and sleep apnea syndrome (SAS) are (one of) the main complaints. In addition, parasomnia is also frequent in this age group. Several parasomnias frequently found in the elderly are reviewed. Periodic limb movements in sleep (PLMS), restless legs syndrome (RLS), and REM sleep behavior disorder are the most frequent parasomnias in old age. Most parasomnias could be diagnosed by polysomnography, and be treated easily. Therefore, early and precise diagnosis and management for parasomnia in aging people are needed.

• 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.

• Biomedical Science Letters
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• v.24 no.3
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• pp.253-262
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• 2018

Platelets are activated at sites of vascular injury via several molecules, such as adenosine diphosphate, collagen and thrombin. Full platelet aggregation is absolutely essential for normal hemostasis. Moreover, this physiological event can trigger circulatory disorders, such as thrombosis, atherosclerosis, and cardiovascular disease. Therefore, platelet function inhibition is a promising approach in preventing platelet-mediated circulatory disease. Many studies reported the involvement of mitogen-activated protein kinases (MAPKs) signaling pathways in platelet functions. However, these studies were limited. Thus, we examined MAPK signaling pathways in human platelets using specific MAPK inhibitors, such as PD98059, SB203580, and SP600125. We observed that these inhibitors were involved in calcium mobilization and influx in human platelets. They also suppressed thrombin-induced ${\alpha}$- and ${\delta}$-granule release. These results suggest that PD98059, SB203580, and SP600125 exhibit $Ca^{2+}$ antagonistic effects.

• BMB Reports
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• v.42 no.8
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• pp.467-474
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• 2009

The modification of proteins by reversible phosphorylation is a key mechanism in the regulation of various physiological functions. Abnormal protein kinase or phosphatase activity can cause disease by altering the phosphorylation of critical proteins in normal cellular and disease processes. Alzheimer' disease (AD), typically occurring in the elderly, is an irreversible, progressive brain disorder characterized by memory loss and cognitive decline. Accumulating evidence suggests that protein kinase and phosphatase activity are altered in the brain tissue of AD patients. Tau is a highly recognized phosphoprotein that undergoes hyperphosphorylation to form neurofibrillary tangles, a neuropathlogical hallmark with amyloid plaques in AD brains. This study is a brief overview of the altered protein phosphorylation pathways found in AD. Understanding the molecular mechanisms by which the activities of protein kinases and phosphatases are altered as well as the phosphorylation events in AD can potentially reveal novel insights into the role aberrant phosphorylation plays in the pathogenesis of AD, providing support for protein phosphorylation as a potential treatment strategy for AD.

• BMB Reports
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• v.51 no.3
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• pp.106-118
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• 2018

How the organ size is adjusted to the proper size during development and how organs know that they reach the original size during regeneration remain long-standing questions. Based on studies using multiple model organisms and approaches for over 20 years, a consensus has been established that the Hippo pathway plays crucial roles in controlling organ size and maintaining tissue homeostasis. Given the significance of these processes, the dysregulation of the Hippo pathway has also implicated various diseases, such as tissue degeneration and cancer. By regulating the downstream transcriptional coactivators YAP and TAZ, the Hippo pathway coordinates cell proliferation and apoptosis in response to a variety of signals including cell contact inhibition, polarity, mechanical sensation and soluble factors. Since the core components and their functions of the Hippo pathway are evolutionarily conserved, this pathway serves as a global regulator of organ size control. Therefore, further investigation of the regulatory mechanisms will provide physiological insights to better understand tissue homeostasis. In this review, the historical developments and current understandings of the regulatory mechanism of Hippo signaling pathway are discussed.

• Journal of Ginseng Research
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• v.36 no.4
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• pp.354-368
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• 2012

Thousands of literatures have described the diverse role of ginseng in physiological processes such as cancer, neurodegenera tive disorders, insulin resistance, and hypertension. In particular, ginseng has been extensively reported to maintain homeostasis of the immune system and to enhance resistance to illness or microbial attacks through the regulation of immune system. Immune system comprises of different types of cells fulfilling their own specialized functions, and each type of the immune cells is differentially influenced and may be simultaneously controlled by ginseng treatment. This review summarizes the current knowledge on the effects of ginseng on immune system. We discuss how ginseng regulates each type of immune cells including macrophages, natural killer cells, dendritic cells, T cells, and B cells. We also describe how ginseng exhibits beneficial effects on controlling inflammatory diseases and microbial infections.