• Title/Summary/Keyword: Phase potential

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An Exploratory Study on the Applicability of Tactics in Team Performance Evaluation

  • Jungsu MOON;Ilhyeok PARK;Nam-Su KIM
    • Journal of Sport and Applied Science
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    • v.8 no.3
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    • pp.21-33
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    • 2024
  • Purpose: The purpose of this study is to explore, extract and categorize the team's tactical factors in soccer matches. Tactical factors are extracted on the basis of the phases consisting a football match (attack, defense, attacking transition, and defensive transition). Research design, data, and methodology: A semi-structural interviews were conducted with a group of experts of five football managers and coaches to explore tactical factors. Analysis of the content was done using a categorical aggregation or direct interpretation, and then was conducted factorial extraction and categorization. Results: In the attack phase, a direct attack and a step-by-step (occupation) attack form the type of attack, and in the attack transition phase, a long counter attack and a short counter attack form the type of attack. The type of defense in the defense phase was divided into regional defense and compression defense, and the type of defense in the defense transition phase was divided into defense for delaying counterattacks and defense for immediate pressure. Each tactics appeared differently depending on the situation of the game and the play of style. Conclusions: It may indicate the team's performance and has the potential for being used as a team performance factor. Further implications were discussed.

Evoked Potential Estimation using the Iterated Bispectrum and Correlation Analysis (Bispectrum 및 Correlation 을 이용한 뇌유발전위 검출)

  • Han, S.W.;Ahn, C.B.
    • Proceedings of the KOSOMBE Conference
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    • v.1994 no.12
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    • pp.113-116
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    • 1994
  • Estimation of the evoked potential using the iterated bispectrum and cross-correlation (IBC) has been tried for both simulation and real clinical data. Conventional time average (TA) method suffers from synchronization error when the latency time of the evoked potential is random, which results in poor SNR distortion in the estimation of EP waveform. Instead of EP signal average in time domain, bispectrum is used which is insensitive to time delay. The EP signal is recovered by the inverse transform of the Fourier amplitude and phase obtained from the bispectrum. The distribution of the latency time is calculated using cross-correlation between EP signal estimated by the bispectrum and the acquired signal. For the simulation. EEG noise was added to the known EP signal and the EP signal was estimated by both the conventional technique and bispectrum technique. The proposed bispectrum technique estimates EP signal more accurately than the conventional technique with respect to the maximum amplitude of a signal, full width at half maximum(FWHM). signal-to-noise-ratio, and the position of maximum peak. When applied to the real visual evoked potential(VEP) signal. bispectrum technique was able to estimate EP signal more distinctively. The distribution of the latency time may play an important role in medical diagonosis.

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The effect of introduced method of titania and applied potential on the photoelectrocatalytic properties of CNT/TiO2 electrodes

  • Zhang, Feng-Jun;Chen, Ming-Liang;Oh, Won-Chun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.1
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    • pp.35-42
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    • 2010
  • In this paper, three types of CNT/$TiO_2$ composite electrodes were prepared with different methods. The changes in XRD patterns showed that the Electrode A contained a mixed phase of anatase and rutile while the Electrode B and Electrode C contained a typical single and clear anatase crystal structure. From SEM micrographs, $TiO_2$ particles were adhered on the surface of the CNT network in the forms of small clusters. The results of chemical elemental analysis indicated that the main elements such as C, O and Ti were existed. The results demonstrated that the efficiency of photoelectrocatalytic (PEC) oxidation for methylene blue (MB) was higher than that of photocatalytic (PC) oxidation. There was a clear enhancement trend of the MB degradation using the prepared CNT/$TiO_2$ composite electrodes with an increase of applied potential. Finally, the prominent PEC activities of the CNT/$TiO_2$ composites could be attributed to combination effects of photo-degradation of $TiO_2$, electron assistant of CNT and function of applied potential.

Effect of Cigarette Filter on Cytotoxicity Potential of Mainstream Smoke (담배주류연의 세포독성에 대한 담배필터의 영향)

  • Shin Han-Jae;Sohn Hyung-Ok;Han Jung-Ho;Park Chul-Hoon;Hur Jae-Yeon;Lee Dong-Wook;Hwang Keon-Joong;Hyun Hak-Chul
    • Journal of the Korean Society of Tobacco Science
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    • v.27 no.1 s.53
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    • pp.51-58
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    • 2005
  • The objective of this study was to evaluate the effect of cigarette filter on in vitro cytotoxicity of cigarette mainstream smoke from the cigarette. In this work, we used 3 types of cigarettes included non-filtered 2R4F cigarette, cellulose acetate-filtered 2R4F cigarette, and carbon dual-filtered 2R4F cigarette which was made from original 2R4F by replacing with an acetate filter containing carbon. The cytotoxicity of both the cigarette smoke condensate (CSC), which was collected in Cambridge filter pad, and the gas/vapor phase (GVP), which was bubbled through in phosphate-buffered saline in a gas-washing bottle, was determined using a neutral red uptake assay with CHO-K1 cells. With regard to cytotoxicity when calculated on an equal puff basis, the cytotoxicity of CSC from the filtered cigarettes was lower than that of the non filtered cigarette. Also, $EC_{50}$ vlaue of GVP from carbon filter cigarette was 40.9 puff/L, indicating the cytotoxicity to be $20\%$ lower than that of the CA filter cigarette. The cytotoxicity of the GVP was correlated to the several vapor phase components (formaldehyde, acetaldehyde, acetone, acrolein, crotonaldehyde and MEK). In conclusion, carbon filter, which significantly reduced the amount of carbonyl compounds in mainstream cigarette smoke, results in significant reductions in the cytotoxicity potential of the smoke.

Changes in Nerve Excitability During Neural Stretching (신경 신장 적용 시간에 따른 신경흥분성 변화)

  • Lee, Dong-Rour;Rhee, Min-Hyung;Eom, Ju-Ri;Kim, Jong-Soon
    • PNF and Movement
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    • v.16 no.2
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    • pp.287-294
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    • 2018
  • Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

Preparation, Characterization and Cytotoxicity of Silibinin-Containing Nanoniosomes in T47D Human Breast Carcinoma Cells

  • Amiri, Boshra;Ebrahimi-Far, Meysam;Saffari, Zahra;Akbarzadeh, Azim;Soleimani, Esmaeil;Chiani, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.3835-3838
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    • 2016
  • Background: Breast cancer is one of the most frequent cancer types within female populations. Silibinin is a chemotherapeutic agent ative against cancer. Niosomes are biodegradable, biocompatible, safe and effective carriers for drug delivery. Objective:To prepare nanoniosomal silibinin and evaluate its cytotoxicity inthe T-47D breast cancer cell line. Materials and Methods: Niosomes were prepared by reverse phase evaporation of a mixture of span 20, silibinin, PEG-2000 and cholesterol in chloroform and methanol solvent (1:2 v/v). The solvent phase was evaporated using a rotary evaporator and the remaining gel phase was hydrated in phosphate buffer saline. Mean size, size distribution and zeta potential of niosomes were measured with a Zetasizer instrument and then nanoparticles underwent scanning electron microscopy. The drug releasing pattern was evaluated by dialysis and the cytotoxicity of nanoniosomes in T-47D cells was assessed by MTT assay. Results: Particle size, size variation and zeta potential of the niosomal nanoparticles were measured as $178.4{\pm}5.4nm$, $0.38{\pm}0.09$ and $-15.3{\pm}1.3mV$, respectively. The amount of encapsulated drug and the level of drug loading were determined $98.6{\pm}2.7%$ and $22.3{\pm}1.8%$, respectively; released drug was estimated about $18.6{\pm}2.5%$ after 37 hours. The cytotoxic effects of nanoniosome were significantly increased when compared with the free drug. Conclusions: This study finding suggests that silibinin nanoniosomes could serve as a new drug formulation for breast cancer therapy.

Vitexicarpin Induces Apoptosis in Human Prostate Carcinoma PC-3 Cells through G2/M Phase Arrest

  • Meng, Fan-Min;Yang, Jing-Bo;Yang, Chun-Hui;Jiang, Yu;Zhou, Yong-Feng;Yu, Bo;Yang, Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6369-6374
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    • 2012
  • Vitexicarpin (3', 5-dihydroxy-3, 4', 6, 7-tetramethoxyflavone), a polymethoxyflavone isolated from Viticis Fructus (Vitex rotundifolia Linne fil.), has long been used as an anti-inflammatory herb in traditional Chinese medicine. It has also been reported that vitexicarpin can inhibit the growth of various cancer cells. However, there is no report elucidating its effect on human prostate carcinoma cells. The aim of the present study was to examine the apoptotic induction activity of vitexicarpin on PC-3 cells and molecular mechanisms involved. MTT studies showed that vitexicarpin dose-dependently inhibited growth of PC-3 cells with an $IC_{50}{\sim}28.8{\mu}M$. Hoechst 33258 staining further revealed that vitexicarpin induced apoptotic cell death. The effect of vitexicarpin on PC-3 cells apoptosis was tested using prodium iodide (PI)/Annexin V-FITC double staining and flow cytometry. The results indicated that vitexicarpin induction of apoptotic cell death in PC-3 cells was accompanied by cell cycle arrest in the G2/M phase. Furthermore, our study demonstrated that vitexicarpin induction of PC-3 cell apoptosis was associated with upregulation of the proapoptotic protein Bax, and downregulation of antiapoptotic protein Bcl-2, release of Cytochrome c from mitochondria and decrease in mitochondrial membrane potential. Our findings suggested that vitexicarpin may become a potential leading drug in the therapy of prostate carcinoma.

Variation of Transcribed X-linked Genes in Bovine Embryos Cloned with Fibroblasts at Different Age and Cell Cycle

  • Jeon, Byeong-Gyun;Rho, Gyu-Jin
    • Reproductive and Developmental Biology
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    • v.35 no.2
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    • pp.175-183
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    • 2011
  • The present study compared the developmental potential, telomerase activity and transcript levels of X-linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) in the bovine somatic cell nuclear transfer (SCNT) embryos derived from different age and cell cycle of female donor nucleus. In experiment 1, the fusion rate, cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cells was slightly increased in embryos cloned with fetal fibroblasts compared to those with adult fibroblasts, but there was no significantly (p<0.05) differences. Telomerase activity was also similar in blastocysts cloned with fetal and adult fibroblasts. Up-regulated RPS4X and down-regulated MeCP2, XIAP, and XIST transcript level were observed in blastocysts cloned with adult fibroblasts, compared to those with fetal fibroblasts. In experiment 2, the fusion rate, cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cells was significantly (p<0.05) increased in embryos cloned with fetal fibroblasts at early G1 phase of the cell cycle, compared to those of fetal fibroblasts at late G1 phase. DNMT1 transcript was observed to significantly (p<0.05) increased in the fetal fibroblasts at 3 hrs after trypsin treatment of confluent culture. Further, level of telomerase activity and transcribed X-linked genes was also significantly (p<0.05) higher in the early G1 SCNT blastocysts than those of late G1. The results imply that fetal fibroblasts at early G1 phase induces the enhanced developmental potential and up-regulated telomerase activity and X-linked gene, but aberrant transcript pattern of X-linked genes may be displayed in the SCNT embryos.

Impact of vitamin D supplementation as COVID-19 vaccine adjuvant on sperm parameters and sex hormones in men with idiopathic infertility: Two separate pre-post studies

  • Mahtab Zarepoor;Alireza Nazari;Soheila Pourmasumi
    • Clinical and Experimental Reproductive Medicine
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    • v.51 no.2
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    • pp.125-134
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    • 2024
  • Objective: Vitamin D deficiency is a major problem for human health worldwide. The mechanisms of vitamin D in the male reproductive system are unknown. After coronavirus disease 2019 (COVID-19) vaccines were developed, doubts were raised about their possible effects on male fertility. Based on vitamin D's function in the immune system, its potential role as an adjuvant for COVID-19 vaccines is intriguing. The aims of this study were to assess the effects of vitamin D first on sperm parameters and sex hormones, and then as an immune adjuvant on sperm parameters and sex hormones after study participants had received their second doses of COVID-19 vaccines. Methods: Phase 1 (before the COVID-19 pandemic) included 72 men with idiopathic infertility, and phase 2 had 64 participants who received two doses of COVID-19 vaccines. Both groups were instructed to take 50,000 IU of vitamin D twice monthly for 3 months. Sperm parameters and sex hormones were assessed pre-and post-supplementation. Results: Regular vitamin D intake for 3 months significantly increased the participants' vitamin D levels (p=0.0001). Both phases showed a positive correlation between vitamin D intake and sperm parameters. Vaccination had no negative effects on sperm parameters and sex hormones. Vitamin D was associated with follicle-stimulating hormone (p=0.02) and testosterone (p=0.0001) in phase 2 after treatment. Conclusion: Our results support vitamin D supplementation as an immune adjunct to COVID-19 vaccination for improving sperm parameters and hormone levels. COVID-19 vaccination is not harmful for male fertility potential, and vitamin D is an effective factor for male fertility.

Effect of Oxidation Temperature on Compound Layer Formation and Corrosion Resistance of Oxy-nitrided GC250 (산질화된 GC250의 화합물층 형성 및 내식성에 미치는 산화 온도의 영향)

  • Minjae Jeong;Kyuntaek Cho;Won-Beom Lee
    • Journal of the Korean Society for Heat Treatment
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    • v.37 no.5
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    • pp.207-214
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    • 2024
  • This study examines the effects of post-oxidation treatment on the microstructure and corrosion resistance of GC250 cast iron. The nitriding process was conducted at 570℃ for 180 minutes with a fixed nitriding potential (Kn) of 1.5, followed by post-oxidation at 450℃, 500℃, and 550℃ for 120 minutes. The post-oxidized specimens showed increased surface hardness and case depth compared to the nitrided specimens, with a maximum surface hardness of approximately 890 HV0.1. The oxidation process increased the thickness of the nitrided layer by more than 3 ㎛, with the oxide layer thickness reaching up to 2.5㎛ as the oxidation temperature increased. XRD analysis identified the presence of ε-phase, γ'-phase, and Fe3O4 phase on the surface. Polarization tests revealed that the specimen treated at the highest oxidation temperature had a corrosion current density of 20.26 ㎂/cm2 and a corrosion potential of -0.22V, indicating enhanced corrosion resistance compared to the nitrided specimen. This improvement is attributed to the formation and increased thickness of the oxide layer, which enhances corrosion resistance. In conclusion, the oxide layer formed through post-oxidation treatment significantly improves the corrosion resistance of GC250 cast iron, with the effect becoming more pronounced at higher oxidation temperatures.