• 제목/요약/키워드: alpha channel

검색결과 293건 처리시간 0.024초

Partial Principal Component Elimination Method and Extended Temporal Decorrelation Method for the Exclusion of Spontaneous Neuromagnetic Fields in the Multichannel SQUID Magnetoencephalography

  • Kim, Kiwoon;Lee, Yong-Ho;Hyukchan Kwon;Kim, Jin-Mok;Kang, Chan-Seok;Kim, In-Seon;Park, Yong-Ki
    • Progress in Superconductivity
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    • 제4권2호
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    • pp.114-120
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    • 2003
  • We employed a method eliminating a temporally partial principal component (PC) of multichannel-recorded neuromagnetic fields for excluding spatially correlated noises from event-evoked signals. The noises in magnetoencephalography (MEG) are considered to be mainly spontaneous neuromagnetic fields which are spatially correlated. In conventional MEG experiments, the amplitude of the spontaneous neuromagnetic field is much lager than that of the evoked signal and the synchronized characteristics of the correlated rhythmic noise makes it possible for us to extract the correlation noises from the evoked signal by means of the general PC analysis. However, the whole-time PC of the fields still contains a little projection component of the evoked signal and the elimination of the PC results in the distortion of the evoked signal. Especially, the distortion will not be negligible when the amplitude of the evoked signal is relatively large or when the evoked signals have a spatially-asymmetrical distribution which does not cancel out the corresponding elements of the covariance matrix. In the period of prestimulus, there are only the spontaneous fields and we can find the pure noise PC that is not including the evoked signal. Besides that, we propose a method, called the extended temporal decorrelation method (ETDM), to suppress the distortion of the noise PC from remanent evoked signal components. In this study, we applied the Partial Principal component elimination method (PPCE) and ETDM to simulated signals and the auditory evoked signals that had been obtained with our homemade 37-channel magnetometer-based SQUID system. We demonstrate here that PPCE and ETDM reduce the number of epochs required in averaging to about half of that required in conventional averaging.

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가정폭력을 경험한 피해자녀의 감정 특성에 관한 정량화 뇌파연구 (Quantitative EEG Analysis on Emotional characteristics of Children experiencing Domestic Violence)

  • 변윤언;원희욱
    • 한국산학기술학회논문지
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    • 제18권11호
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    • pp.166-175
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    • 2017
  • 이 연구는 범죄피해자 지원기관인 (사)한국피해자지원협회(KOVA; Korea Organization Victicm Assistance)에서 2017년 7월 피해상담 전문가의 심리상담을 진행한 두 폭력 가정의 피해자녀들을 대상으로 이루어졌다. 연구참여자는 가정폭력에 대한 피해 호소가 10년이 넘은 가정으로서 폭력피해사실에 대해 경찰서에 직접 신고되어 접수된 이력이 있고 또 피해자녀와 피해자인 어머니가 단기쉼터에 입소하여 함께 거주한 경험이 있는 가정이었다. 가정폭력의 경우 자녀들은 특히, 미성년자인 경우 부모가 제공하는 생활공간에서 폭력피해를 입더라도 자발적으로 벗어나기 어려운 상태에 있으며, 폭력경험을 지속적이고 반복적으로 당하게 된다. 이에 가정폭력 피해자녀들이 현재 가해자-피해자 관계의 부모와 함께 거주하면서 어떤 감정 양상을 나타내고 있는지 그 특성을 정량화된 뇌파 데이터를 수집하고 분석하여 확인하고자 하였다. 뇌파측정은 서울불교대학원 부설 뇌과학연구소에서 진행하였으며, 뇌파측정 데이터 수집은 국제적으로 표준화된 19채널 뇌파측정도구인 브레인마스터를 사용하였고, 데이터 처리는 뉴로가이드를 사용하였다. 가정폭력을 경험한 피해자녀의 감정양상을 정량적 수치 및 뇌지형도를 통하여 분석한 결과 전두엽에 있어서 과잉서파의 문제, 알파파 좌우비대칭, 고베타파 좌우비대칭의 문제를 발견하였다.

Pharmacologic Management of Chronic Pain

  • Park, Hue-Jung;Moon, Dong-Eon
    • The Korean Journal of Pain
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    • 제23권2호
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    • pp.99-108
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    • 2010
  • Chronic pain is a multifactorial condition with both physical and psychological symptoms, and it affects around 20% of the population in the developed world. In spite of outstanding advances in pain management over the past decades, chronic pain remains a significant problem. This article provides a mechanism- and evidence-based approach to improve the outcome for pharmacologic management of chronic pain. The usual approach to treat mild to moderate pain is to start with a nonopioid analgesic. If this is inadequate, and if there is an element of sleep deprivation, then it is reasonable to add an antidepressant with analgesic qualities. If there is a component of neuropathic pain or fibromyalgia, then a trial with one of the gabapentinoids is appropriate. If these steps are inadequate, then an opioid analgesic may be added. For moderate to severe pain, one would initiate an earlier trial of a long term opioid. Skeletal muscle relaxants and topicals may also be appropriate as single agents or in combination. Meanwhile, the steps of pharmacologic treatments for neuropathic pain include (1) certain antidepressants (tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors), calcium channel ${\alpha}2-{\delta}$ ligands (gabapentin and pregabalin) and topical lidocaine, (2) opioid analgesics and tramadol (for first-line use in selected clinical circumstances) and (3) certain other antidepressant and antiepileptic medications (topical capsaicin, mexiletine, and N-methyl-d-aspartate receptor antagonists). It is essential to have a thorough understanding about the different pain mechanisms of chronic pain and evidence-based multi-mechanistic treatment. It is also essential to increase the individualization of treatment.

Increase of Intracellular $Ca^{2+}$ Concentration Induced by Lysophosphatidylcholine in Murine Aortic Endothelial Cells

  • Zhu, Mei-Hong;Park, Sung-Jin;Kim, Hyun-Jin;Yang, Dong-Ki;Suh, Suk-Hyo;So, In-Suk;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • 제6권2호
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    • pp.93-99
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    • 2002
  • Effects of oxidized low-density lipoprotein (ox-LDL), $1-{\alpha}-stearoyl-lysophosphatidylcholine$ (LPC), on intracellular $Ca^{2+}$ concentration were examined in mouse endothelial cells by measuring intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ with fura 2-AM and reverse transcription-polymerase chain reaction (RT-PCR). LPC increased $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o$ but did not show any effect under the nominally $Ca^{2+}-free$ condition. Even after the store depletion with $30{\mu}M$ 2,5-di-tert- butylhydroquinone (BHQ) or $30{\mu}M$ ATP, LPC could still increase the $[Ca^{2+}]_i$ under the condition of 1.5 mM $[Ca^{2+}]_o.$ The time required to increase [$Ca{2+}$]i (about 1 minute) was longer than that for ATP-induced $[Ca^{2+}]_i$ increase $(10{\sim}30\;seconds).$ LPC-induced $[Ca^{2+}]_i$ increase was completely blocked by $1{\mu}M\;La^{3+}.$ Transient receptor potential channel(trpc) 4 mRNA was detected with RT-PCR. From these results, we suggest that LPC increased $[Ca^{2+}]_i$ via the increase of $Ca^{2+}$ influx through the $Ca^{2+}$ routes which exist in the plasma membrane.

A Gas-Phase Investigation of Oxygen-Hydrogen Exchange Reaction of O(3P) + C2H5 → H(2S) + C2H4O

  • Jang, Su-Chan;Park, Min-Jin;Choi, Jong-Ho
    • Bulletin of the Korean Chemical Society
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    • 제35권3호
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    • pp.839-844
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    • 2014
  • The gas-phase radical-radical reaction $O(^3P)$ + $C_2H_5$ (ethyl) ${\rightarrow}$ $H(^2S)$ + $CH_3CHO$(acetaldehyde) was investigated by applying a combination of vacuum-ultraviolet laser-induced fluorescence spectroscopy in a crossed beam configuration and ab initio calculations. The two radical reactants $O(^3P)$ and $C_2H_5$ were respectively produced by photolysis of $NO_2$ and supersonic flash pyrolysis of the synthesized precursor azoethane. Doppler profile analysis of the nascent H-atom products in the Lyman-${\alpha}$ region revealed that the average translational energy of the products and the average fraction of the total available energy released as translational energy were $5.01{\pm}0.72kcalmol^{-1}$ and 6.1%, respectively. The empirical data combined with CBS-QB3 level ab initio theory and statistical calculations demonstrated that the title exchange reaction is a major channel and proceeds via an addition-elimination mechanism through the formation of a short-lived, dynamical addition complex on the doublet potential energy surface. On the basis of systematic comparison with several exchange reactions of hydrocarbon radicals, the observed small kinetic energy release can be explained in terms of the loose transition state with a product-like geometry and a small reverse activation barrier along the reaction coordinate.

In vitro performance and fracture resistance of novel CAD/CAM ceramic molar crowns loaded on implants and human teeth

  • Preis, Verena;Hahnel, Sebastian;Behr, Michael;Rosentritt, Martin
    • The Journal of Advanced Prosthodontics
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    • 제10권4호
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    • pp.300-307
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    • 2018
  • PURPOSE. To investigate the fatigue and fracture resistance of computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic molar crowns on dental implants and human teeth. MATERIALS AND METHODS. Molar crowns (n=48; n=8/group) were fabricated of a lithium-disilicate-strengthened lithium aluminosilicate glass ceramic (N). Surfaces were polished (P) or glazed (G). Crowns were tested on human teeth (T) and implant-abutment analogues (I) simulating a chairside (C, crown bonded to abutment) or labside (L, screw channel) procedure for implant groups. Polished/glazed lithium disilicate (E) crowns (n=16) served as reference. Combined thermal cycling and mechanical loading (TC: $3000{\times}5^{\circ}C/3000{\times}55^{\circ}C$; ML: $1.2{\time}10^6$ cycles, 50 N) with antagonistic human molars (groups T) and steatite spheres (groups I) was performed under a chewing simulator. TCML crowns were then analyzed for failures (optical microscopy, SEM) and fracture force was determined. Data were statistically analyzed (Kolmogorow-Smirnov, one-way-ANOVA, post-hoc Bonferroni, ${\alpha}=.05$). RESULTS. All crowns survived TCML and showed small traces of wear. In human teeth groups, fracture forces of N crowns varied between $1214{\pm}293N$ (NPT) and $1324{\pm}498N$ (NGT), differing significantly ($P{\leq}.003$) from the polished reference EPT ($2044{\pm}302N$). Fracture forces in implant groups varied between $934{\pm}154N$ (NGI_L) and $1782{\pm}153N$ (NPI_C), providing higher values for the respective chairside crowns. Differences between polishing and glazing were not significant ($P{\geq}.066$) between crowns of identical materials and abutment support. CONCLUSION. Fracture resistance was influenced by the ceramic material, and partly by the tooth or implant situation and the clinical procedure (chairside/labside). Type of surface finish (polishing/glazing) had no significant influence. Clinical survival of the new glass ceramic may be comparable to lithium disilicate.

칼슘 길항제가 심장 ${\beta}$-Adrenergic Receptors에 미치는 영향 (Effect of Calcium Antagonists on the Cardiac ${\beta}$-Adrenergic Receptors)

  • 이신웅;김정구
    • Biomolecules & Therapeutics
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    • 제1권1호
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    • pp.1-8
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    • 1993
  • It has been known that calcium antagonists also inhibit the radioligand binding to muscarinic and $\alpha$-adrenergic receptors and, in case of verapamil, these inhibitions may play a role in the effects of verapamil on the heart. In this study, the effects of nicardipine, nifedipine, nimodipine, diltiazem and verapamil on the binding of [$^3H$]dihydroalprenolol (DHA) to dog cardiac ${\beta}$-adrenergic receptors were examined. A single uniform [$^3H$]DHA binding site ($K_D/= 5nM\;and\;B_{max}=2600$ fmol/mg protein) was identified in dog cardiac sarcolemma. [$^3H$]DHA binding was not affected by the usual therapeutic concentrations of these calcium antagonists (nanomolar range) but in the "nonspecific"concentration ranges ($28-180{\mu}m$) these drugs inhibited [$^3H$]DHA binding to $\beta$-adrenergic receptors. Nicardipine, nifedipine, nimodipine and diltiazem competed for [$^3H$]DHA binding to ${\beta}$-adrenergic receptors with dissociation constants ($K_i$) of $28{\mu}m,\' 74{\mu}m, 39{\mu}m \;and \;35{\mu}m,$ respectively. Verapamil ($K_i=176.5 {\mu}m$) was less potent inhibitor than other drugs and this inhibition was noncompetitive; the maximal binding capacity ($B_{max}$) $300 {\mu}m$ verapamil without change in the apparent dissociation constant (4K_D$) for DHA. These results indicate that the inhibitory action of calcium antagonists at high concentrations on ${\beta}$-adrenergic receptors is not involved in the therapeutic effects of these drugs by the calcium channel blocking action.

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Comparison of fit accuracy and torque maintenance of zirconia and titanium abutments for internal tri-channel and external-hex implant connections

  • Siadat, Hakimeh;Beyabanaki, Elaheh;Mousavi, Niloufar;Alikhasi, Marzieh
    • The Journal of Advanced Prosthodontics
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    • 제9권4호
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    • pp.271-277
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    • 2017
  • PURPOSE. This in vitro study aimed to evaluate the effect of implant connection design (external vs. internal) on the fit discrepancy and torque loss of zirconia and titanium abutments. MATERIALS AND METHODS. Two regular platform dental implants, one with external connection ($Br{\aa}nemark$, Nobel Biocare AB) and the other with internal connection (Noble Replace, Nobel Biocare AB), were selected. Seven titanium and seven customized zirconia abutments were used for each connection design. Measurements of geometry, marginal discrepancy, and rotational freedom were done using video measuring machine. To measure the torque loss, each abutment was torqued to 35 Ncm and then opened by means of a digital torque wrench. Data were analyzed with two-way ANOVA and t-test at ${\alpha}=0.05$ of significance. RESULTS. There were significant differences in the geometrical measurements and rotational freedom between abutments of two connection groups (P<.001). Also, the results showed significant differences between titanium abutments of internal and external connection implants in terms of rotational freedom (P<.001). Not only customized internal abutments but also customized external abutments did not have the exact geometry of prefabricated abutments (P<.001). However, neither connection type (P=.15) nor abutment material (P=.38) affected torque loss. CONCLUSION. Abutments with internal connection showed less rotational freedom. However, better marginal fit was observed in externally connected abutments. Also, customized abutments with either connection could not duplicate the exact geometry of their corresponding prefabricated abutment. However, neither abutment connection nor material affected torque loss values.

Detection of copy number variation and selection signatures on the X chromosome in Chinese indigenous sheep with different types of tail

  • Zhu, Caiye;Li, Mingna;Qin, Shizhen;Zhao, Fuping;Fang, Suli
    • Asian-Australasian Journal of Animal Sciences
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    • 제33권9호
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    • pp.1378-1386
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    • 2020
  • Objective: Chinese indigenous sheep breeds can be classified into the following three categories by their tail morphology: fat-tailed, fat-rumped and thin-tailed sheep. The typical sheep breeds corresponding to fat-tailed, fat-rumped, and thin-tailed sheep are large-tailed Han, Altay, and Tibetan sheep, respectively. Detection of copy number variation (CNV) and selection signatures provides information on the genetic mechanisms underlying the phenotypic differences of the different sheep types. Methods: In this study, PennCNV software and F-statistics (FST) were implemented to detect CNV and selection signatures, respectively, on the X chromosome in three Chinese indigenous sheep breeds using ovine high-density 600K single nucleotide polymorphism arrays. Results: In large-tailed Han, Altay, and Tibetan sheep, respectively, a total of six, four and 22 CNV regions (CNVRs) with lengths of 1.23, 0.93, and 7.02 Mb were identified on the X chromosome. In addition, 49, 34, and 55 candidate selection regions with respective lengths of 27.49, 16.47, and 25.42 Mb were identified in large-tailed Han, Altay, and Tibetan sheep, respectively. The bioinformatics analysis results indicated several genes in these regions were associated with fat, including dehydrogenase/reductase X-linked, calcium voltage-gated channel subunit alpha1 F, and patatin like phospholipase domain containing 4. In addition, three other genes were identified from this analysis: the family with sequence similarity 58 member A gene was associated with energy metabolism, the serine/arginine-rich protein specific kinase 3 gene was associated with skeletal muscle development, and the interleukin 2 receptor subunit gamma gene was associated with the immune system. Conclusion: The results of this study indicated CNVRs and selection regions on the X chromosome of Chinese indigenous sheep contained several genes associated with various heritable traits.

Ionomycin Recovers Taurine Transporter Activity in Cyclosporin A Treated macrophages

  • Kim, Ha-Won;Lee, Eun-Jin;Kim, Won-Bae;Hyun, Jin -Won;Kim, Byung-Kak
    • Preventive Nutrition and Food Science
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    • 제4권4호
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    • pp.265-269
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    • 1999
  • Taurine is a major $\beta$-amino acid in various tissues. Taurine transporter (TAUT) is responsible for the transportation of taurine in the cell. The transporter is affected by various stimuli to maintain its cell volume. Macrophage cell volume varies in its activated states. In our experiment, it was found that the murine macrophage cell line, RAW264.7, expressed TAUT protein in its membrane. Its transportation activities could be blocked by a $\beta$-amino acid such as $\beta$-alanine, but not by $\alpha$-amino acids in this cell line. When assessed in RAW264.7 under the influence of immunosuppressive reagents, the activity of the TAUT was decreased by the treatment of rapamycin (RM) or cyclosporin A (CsA). However when ionomycin (IM) was added to this system, TAUT activity was recovered only in CsA-treated cells in a concentration-dependent manner. In order to inhibit the voltage gated {TEX}$Ca^{+2}${/TEX} channel, calmidazolium was added to the RAW264.7 cell line. Treatment of the cell with calmidazolium completely blocked TAUT. Furthermore, addition of IM to this system recovered the activity of TAUT again. When we added phorbol myristate acetate (PMA) to the cell line, secretion of nitric oxide (NO) was increased 4-fold and the TAUT activity was decreased 5-fold. However, the addition of N-nitro L-arginine methyl ester (L-NAME), an inducible NO synthase (iNOS) inhibitor, to the PMA-treated cells, resulted in the recovery of TAUT activity. These results showed that the activity of TAUT was sensitive to the intracellular concentrations of both {TEX}$Ca^{+2}${/TEX} and NO.

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