• Title/Summary/Keyword: Receptor Theory

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Near Fields around Metallic Walls due to a Nearby Dipole Source with Applications to EMC

  • Kim, Ki-Chai;Lim, Sung Min;Kim, Jong-Woo
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.329-334
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    • 2017
  • This paper discusses the near field characteristics of a dipole source located near conducting metallic walls from an electromagnetic compatibility (EMC) point of view. An integral equation for a dipole source near a metallic wall is derived and solved by applying Galerkin's method of moments (MoM). The results show that in the regions outside the dipole source, total electric near fields decrease gradually in magnitude with an increasing field point from the dipole source. But in the regions inside the dipole source, total electric near fields decrease rapidly with a dipole position of $h{\leq}0.3{\lambda}$. For a dipole position of $h{\geq}0.7{\lambda}$, the peaks and nulls of the total near electric field occur periodically in the regions inside the dipole source, and the fluctuation period is almost $0.5{\lambda}$. The worst position for a receptor location is along the z-axis, and a range of a half-magnitude of the maximum near electric field in the principal H-plane is about two times broader than that of the principal E-plane. Experimental measurements are also presented to validate the theory.

Peroxisome Proliferators and Hepatocarcinogenesis

  • Hong, Jin-Tae
    • Environmental Mutagens and Carcinogens
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    • v.17 no.2
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    • pp.78-91
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    • 1997
  • Peroxisome is a single membrane-bounded organelle found in hepatic parenchymal cells and kidney tubular epithelial cells. A number of enzymes exist in peroxisome contributing to anabolic and catabolic peroxisomal functions. Extramitochontriai $\beta$-oxidation of fatty acid is a major function of peroxisome. Peroxisomes can be proliferated by many structually unrelated compounds such as hypolipidemic drugs, plasticizers, pesticides, some pharmaceutical agents and high fat diet. These chemicals, called peroxisome proliferators, act via the peroxisome proliferator activated receptor, to induce peroxisome proliferation, hepatomegaly and hepatocellular carcinoma in rodent. The clear mechanisms of peroxisome proliferator-induced hepatocarcinogenesis have been not demonstrated. Since they are not genotoxic, biochemical changes or changes in gene expressions may be involved. A free radical theory has been suggested based on the finding of oxidative damages of macromolecules by hydrogen peroxide released in the peroxisomal $\beta$-oxidation of fatty acid. Increased cell proliferation by a peroxisome proliferator has been also thought to be an important factor in the hepatocarcinogenesis as suggested in other cases of nongenotoxic carcinogenesis. The alternation of eicosanoid concentrations by peroxisome proliferators may be important in the peroxisome proliferator-induced hepatocarcinogenesis since peroxisome proliferators decrease the concentration of eicosanoids, and the peroxisome proliferator ciprofibrate-eicosanoid combination is comitogenic and costimulates some mitogenic signals in hepatocytes. All of proposed mechanisms should be considered in the peroxisome prolifrator-induced hepatocarcinogenesis.

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Neurobiology of Depression (우울증의 신경생물학)

  • Kim, Young-Hoon;Lee, Sang-Kyeong;Rhee, Chung-Goo;Kim, Jeong-Ik
    • Korean Journal of Biological Psychiatry
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    • v.6 no.1
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    • pp.3-11
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    • 1999
  • At the beginning, researches on the biology of depression or affective illness have focused mainly on the receptor functions and neuroendocrine activities. And the studies of the past years did not break new theoretical background, but the recent advances in the research on the molecular mechanisms underlying neural communication and signal transduction do add some insights to many established ideas. This article will overview some of the more recent advances in the clinical researches of depression. Our major concerns to be presented here include the followings : (1) alterations in the post-synaptic neural transduction ; (2) changes in the neurons of hypothalamic neuropeptides ; (3) decreased peptidase enzyme activities ; (4) associations of hypothalamic-pituitary-adrenal axis abnormalities with serotonin neurotransmission ; (5) role of serotonin transporter ; (6) changes in the responsiveness of intracellular calcium ion levels ; (7) the inositol deficiency theory of lithium and depression ; (8) the transcription factors including immediate early genes ; (9) recent genetic studies in some families. This brief overview will suggest that changes in DNA occur during antidepressant therapy. These changes at the DNA level initiating a cascade of events underlying antidepressant modality will give us the insights on the molecular biological basis of the pathogenesis of depression and cues for a new class of antidepressants.

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Importance of Accurate Charges in Binding Affinity Calculations: A Case of Neuraminidase Series

  • Park, Kichul;Sung, Nack Kyun;Cho, Art E.
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.545-548
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    • 2013
  • It has been shown that calculating atomic charges using quantum mechanical level theory greatly improves the accuracy of docking. A protocol was developed and shown to be effective. That this protocol works is just a manifestation of the fact that electrostatic interactions are important in protein-ligand binding. In order to investigate how the same protocol helps in prediction of binding affinities, we took a series of known cocrystal structures of influenza neuraminidase inhibitors with the receptor and performed docking with Glide SP, Glide XP, and QPLD, the last being a workflow that incorporates QM/MM calculations to replace the fixed atomic charges of force fields with quantum mechanically recalculated ones at a given docking pose, and predicted the binding affinities of each cocrystal. The correlation with experimental binding affinities considerably improved with QPLD compared to Glide SP/XP yielding $r^2$ = 0.83. The results suggest that for binding sites, such as that of neuraminidase, which are laden with hydrophilic residues, protocols such as QPLD which utilizes QM-based atomic charges can better predict the binding affinities.

Effects of Opioid Agonists on the Suppressed Spontaneous Alternation Behaviour in Rats (아편양 순응제가 백서의 억제된 자발적 교대행동에 미치는 영향)

  • Lee, Gi-Chul;Jeon, Seong-Il;Chang, Hwan-Il;Lee, Jung-Ho;Choi, Young-Min;Kim, Seong-Ho;Ryu, Jeong-Hwan;Choi, Mi
    • Korean Journal of Biological Psychiatry
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    • v.6 no.2
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    • pp.193-201
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    • 1999
  • This study was designed to evaluate the effects of opioid receptor agonists on the spontaneous alternation behaviour in an animal model of obsessivecompulsive disorder in rats. According to the theory that dopamine is related to the biological etiology of obsessive-compulsive disorder, the effect of the nalbuphine(opioid kappa agonist) and the tramadol(opioid mu agonist), which act as manipulating agents on the inhibition or stimulation of dopamine release, in the spontaneous alternation behaviour were evaluated. 24 hours prior to the experiment, rats were food-deprived. These rats were put into the T-maze, in which white and black goal boxes were baited with small amounts of chocolate milk. Each rat was given 2 set of 7 trials during which it was placed in the start box and allowed to choose the one of the goal boxes for each time. After identifying the stable baseline of spontaneous alternation behaviour, nonselective 5-HT agonist 5-MeODMT(1.25mg/kg/IP) disrupted spontaneous alternation. Rats were stratified into fluoxetine(10mg/kg/IP), nalbuphine(10mg/kg/IP), tramadol(46.4mg/kg/IP), and saline(0.5cc/IP) injection group with experimental drug treatment for 21 days. The effects on the 5-MeODMT(1.25mg/kg/IP) induced disruption of spontaneous alternation behaviour were checked at the next day of discontinuation of drug treatment. The results were as follows ; 1) At the day after 21 days of the drug treatment, the nalbuphine treated group and the fluoxetine treated group showed significant difference from the tramadol treated group and the saline treated group in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. 2) Within each drug treatment group, the fluoxetine treated group showed significant difference between before and after the treatment of fluoxetine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. And also, the nalbuphine treated group showed significant difference between before and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. There was no difference between the baseline and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. We indentified that the opioid kappa agonist that act as dopamine release inhibitor affect the spontaneous alternation behaviour which is an animal model of obsessive-compulsive disorder in rat.

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Socioeconomic impact of traditional Korean medicine, Pyeongwee-San (KMP6) as an anti-allergic inflammatory drug

  • Song, Young-Hoon;Nam, Sun-Young;Choi, Young-Jin;Kim, Jeong-Hwa;Kim, Young-Sick;Jeong, Hyun-Ja
    • CELLMED
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    • v.2 no.3
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    • pp.29.1-29.9
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    • 2012
  • The prevalence of allergic disease has been increasing over the past few decades in the majority of Western industrialized nations. There are some socioeconomic disparities regarding allergic disease status and management. Pyeongwee-San (KMP6) is Korean medicine for the treatment of gastrointestinal tract disease. It is known that KMP6 has an improving effect on the spleen and stomach functions in traditional Korean medical theory. Here, we hypothesized that KMP6 could be used to regulate the inflammatory reaction. We show the molecular mechanisms of Pyeongwee-San (KMP6) on inflammatory reactions. A molecular docking simulation showed that hesperidin, component of KMP6, regulate the enzymatic activity by interaction in the active site of caspase-1. KMP6 control the activity of caspase-1 in activated human mast cell line (HMC-1 cells). KMP6 reduced the expression of receptor interacting protein (RIP)-2 in HMC-1 cells. Thymic stromal lymphopoietin protein production and mRNA expression were inhibited by KMP6. In the activated HMC-1 cells, KMP6 suppressed the activation of mitogen-ativated protein kinase and nuclear factor-kappaB. In addition, KMP6 significantly inhibited the expression of inflammatory cytokines. Our findings indicate that KMP6 may attenuate allergic reactions via the regulation of caspase-1/RIP-2 signaling pathway. These studies will help advance the social welfare system.

Cancer stem cell theory and update in oral squamous cell carcinoma (구강 편평세포암종에서의 암줄기세포 이론과 최신 지견)

  • Kim, Deok-Hun;Yun, Jun-Yong;Lee, Ju-Hyun;Kim, Soung-Min;Myoung, Hoon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.37 no.2
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    • pp.97-108
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    • 2011
  • Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

Comparison of clinical efficacy of ropivacaine and lignocaine with adrenaline for implant surgery anesthesia: a split-mouth randomized controlled clinical trial

  • Kalath, Remya Nath;Kulal, Rithesh;Gopinath, Sharika
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.21 no.4
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    • pp.337-344
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    • 2021
  • Background: The primary indication for using long-acting anesthetics in dentistry is extensive dental procedures that require pulpal anesthesia beyond 90 min and management of postoperative pain. Ropivacaine is an amide local anesthetic that is available at various concentrations with inherent vasoconstrictive properties at low concentrations. Ropivacaine has a 75% greater margin of safety than bupivacaine. Ropivacaine can be a good alternative to bupivacaine as a local anesthetic in dental implant surgery as it provides a longer duration of both pulpal and soft tissue anesthesia after mandibular nerve block and lowers CNS and cardiovascular toxicity. This study aimed to evaluate and compare the clinical efficacy of ropivacaine and lignocaine for implant surgery anesthesia. Methods: Fifteen patients with bilateral edentulous sites indicated for implant placement were recruited for this study. Patients aged 20-60 years of both sexes were randomly recruited. Thirty implant placements were performed in the test and control groups using ropivacaine and lignocaine with adrenaline as local anesthetics, respectively. Results: The results were analyzed statistically. The duration of anesthesia was significantly higher in the test group than in the control group. Ropivacaine was found to be superior to lignocaine in terms of the quality of anesthesia. The comparison of mean visual analog scale scores showed ropivacaine to have better anesthetic and analgesic effects than the control group. Conclusion: Ropivacaine 0.75% provides a significantly longer duration of anesthesia than lignocaine 2% with adrenaline. Ropivacaine 0.75% decreased intraoperative and postoperative analgesia compared to lignocaine 2% with adrenaline. Hence, ropivacaine 0.75% can be used as an alternative to lignocaine in implant surgeries and other intraoral surgical procedures that require a longer duration of anesthesia and analgesia.

Gene Expression Profiles in Cervical Cancer with Radiation Therapy Alone and Chemo-radiation Therapy (자궁경부암의 방사선치료 및 방사선항암화학 병용치료에 따른 유전자발현 조절양상)

  • Lee Kyu Chan;Kim Meyoung-kon;Kim Jooyoung;Hwang You Jin;Choi Myung Sun;Kim Chul Yong
    • Radiation Oncology Journal
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    • v.21 no.1
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    • pp.54-65
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    • 2003
  • Purpose : To analyze the gene expression Profiles of uterine ceulcal cancer, and its variation after radiation therapy, with or without concurrent chemotherapy, using a CDNA microarray. Materials and Methods :Sixteen patients, 8 with squamous ceil carcinomas of the uterine cervix, who were treated with radiation alone, and the other 8 treated w14h concurrent chemo-radiation, were Included in the study. Before the starling of the treatment, tumor biopsies were carried out, and the second time biopsies were peformed after a radiation dose of 16.2$\~$27 Gy. Three normal cervix tissues were used as a control group. The microarray experiments were peformed with 5 groups of the total RNAs extracted individually and then admixed as control, pre-radiation therapy alone, during-radiation therapy alone, pre-chemoradiation therapy, and during-chemoradlation therapy. The 33P-iabeled CDNAS were synthesized from the total RNAs of each group, by reverse transcription, and then they were hybridized to the CDNA microarray membrane. The gene expression of each microarrays was captured by the intensity of each spot produced by the radioactive isotopes. The pixels per spot were counted with an Arrayguage, and were exported to Microsoft Excel The data were normalized by the Z transformation, and the comparisons were peformed on the Z-ratio values calculated. Results : The expressions of 15 genes, including integrin linked kinase (ILK), CDC28 protein kinase 2, Spry 2, and ERK 3, were increased with the Z-ratio values of over 2.0 for the cervix cancer tissues compared to those for the normal controls. Those genes were involved In cell growth and proliferation, cell cycle control, or signal transduction. The expressions of the other 6 genes, Including G protein coupled receptor kinase 5, were decreased with the Z-ratio values of below -2.0. After the radiation thorapy, most of the genes, with a previously Increase expressions, represented the decreased expression profiles, and the genes, with the Z-ratio values of over 2.0, were cyclic nucleotlde gated channel and 3 Expressed sequence tags (EST). In the concurrent chemo-radiation group, the genes involved in cell growth and proliferation, cell cycle control, and signal transduction were shown to have increased expressions compared to the radiation therapy alone group. The expressions of genes involved in anglogenesis (angiopoietln-2), immune reactions (formyl peptide receptor-iike 1), and DNA repair (CAMP phosphodiesterase) were increased, however, the expression of gene involved In apoptosls (death associated protein kinase) was decreased. Conclusion : The different kinds of genes involved in the development and progression of cervical cancer were identified with the CDNA microarray, and the proposed theory is that the proliferation signal stalls with ILK, and is amplified with Spry 2 and MAPK signaling, and the cellular mitoses are Increased with the increased expression oi Cdc 2 and cell division kinases. After the radiation therapy, the expression profiles demonstrated 4he evidence of the decreased cancer cell proliferation. There was no sigificant difference in the morphological findings of cell death between the radiation therapy aione and the chemo-radiation groups In the second time biopsy specimen, however, the gene expression profiles were markedly different, and the mechanism at the molecular level needs further study.

A Study On User Experience Based Storydoing Operating Principles (사용자 경험 기반 스토리두잉의 작동원리에 관한 연구)

  • Shin, Dong-Hee;Kim, Hee-Kyung
    • Journal of Digital Contents Society
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    • v.16 no.3
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    • pp.425-436
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    • 2015
  • Along with the spotlight of storytelling, storydoing has attracted public's attention as it has been utilized in various different areas. There are valued message by producer and story to back it up in the storydoing. Recipient will acknowledge the affordance encouraged by producer and confirm the message by practicing it. Finally producer will evaluate the practice process. Therefore, storydoing promotes the product of company, strengthens the brand image and delivers message and value through a previously mentioned cycle. Ultimately, storydoing is operated based on user's experience. In this study, based on the experience theory of John Dewey, in order to discover how the interactivity and continuity operate story doing, we conducted a study on the concept of storydoing, the national and international story doing status, the difference between storytelling and storydoing, the elements of story doing, the relationship with user experience, and the principle of operating story doing. As a result, we learned that story doing had the five elements of message, story, characters, action, and confirmation, and operated by the interaction and continuity between the producer and receptor. Thus, through this research to understand the nature of storydoing, we have identified new trends of the cultural industries and discovered the possibilities to expand the application scope of storydoing, which was currently applied by companies to promote their brand images, onto contents field. More importantly, the proposal of theoretical differences between storytelling and storydoing makes this report meaningful in terms of sociocultural, industrial and academic aspect.