• Title/Summary/Keyword: induction period

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Antioxidative Activity of Some Solvent Extract from Caesalpinia sappan L. (소목 추출물의 항산화 효과)

  • Lim, Dae-Kwan;Choi, Ung;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.28 no.1
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    • pp.77-82
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    • 1996
  • Antioxidative activity of the extract from Caesalpinia sappan L. by various solvent was compared with several commercial antioxidants, using the Rancimat method. AI (antioxidative index; induction period of oil containing extract/induction period of control oil) of all extracts were higher than commercial antioxidants, such as BHA, ${\delta}-tocopherol$ and ascorbic acid. The ethanol extract was fractionated by liquid liquid extraction. Ethyl acetate fraction showed higher AI than the whole crude extract. When comparing POV and TBA value of palm oil and lard containing different level of each fraction, the oxidative stability of ethyl acetate fraction at 200 ppm level on palm oil and lard were similar to that of BHT at 200 ppm level, and better than BHA, ${\delta}-tocopherol$ and control.

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Transmission Characteristics of Long-Period Fiber Gratings Using Periodically Corroded Single-Mode Fibers

  • Lee, Jonghwan;Bang, Ngac An;Han, Young-Geun
    • Journal of the Optical Society of Korea
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    • v.19 no.4
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    • pp.376-381
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    • 2015
  • Transmission characteristics of long-period fiber gratings (LPFGs) fabricated by periodically etching a conventional single-mode fiber (SMF) are investigated. After coating the SMF with photoresist, the cladding of the SMF is symmetrically and periodically removed by using a wet etching technique resulting in the formation of the LPFG. Tensile strain reinforces the coupling strength between the core and the cladding mode based on the photoelastic effect. The extinction ratio of the SMF-based LPFG at a wavelength of 1550.8 nm is measured to be -15.1 dB when the applied strain is $600{\mu}{\varepsilon}$. The ascent of ambient index shifts the resonant wavelength to shorter wavelength because of the increase of the effective refractive index of the cladding mode. The extinction ratio is diminished by increase in the ambient index because of the induction of the optical attenuation of the cladding mode. The transmission characteristics of the proposed LPFG with variations in torsion are also measured. The photoelastic effect based on torsion changes the extinction ratio and the resonant wavelength of the proposed SMF-based LPFG. The polarization-dependent loss of the LPFG is also increased by torsion because of the torsion-induced birefringence. The polarization-dependent loss of the LPFG at torsion of 8.5 rad/m is measured to be 3.9 dB.

Decreased oral bioavailability of cyclosporin A at second administration in human

  • Lee, Young-Joo;Chung, Suk-Jae;Shim, Chang-Koo;Lee, Min-Wha
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1997.04a
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    • pp.117-117
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    • 1997
  • Sandimmune Neoral$\^$(R)/ and Neoplanta$\^$(R)/ capsules were administered to twenty four healthy Korean male subjects at a cyclosporin A (CsA) dose of 175 mg in a 2 ${\times}$ 2 crossover investigation with a two-week wash-out phase. Concentrations of CsA in blood were measured by RIA method for over a period of 48 h. Result : The two formulations were found bioequivalent, but analysis of variance (ANOVA) indicated that there is a significant (p<0.01) period effect in AUC$\_$0-LAST/ (area under the blood concentration above assay limit of quantification-time curve) and C$\_$MAX/ (maximum blood concentration) between the administrations. Paired t-test revealed 6 and 9% decreases in AUC$\_$0-LAST/ and C$\_$MAX/, respectively at the second administration. This period effect on the pharmacokinetics of CsA may be relevant for the patients who need consecutive administration of the drug. A number of mechanisms, such as induction of the enzymes responsible for metabolism of the drug in the gut wall and/or liver and modulation of P-glycoprotein upon the consecutive dosing, appear consistent with the change, and needs experimental proof.

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Pharmacological action of extracts of Scutellaria baicalensis on Cardiovascular System (황금(黃芩)의 심장(心臟)에 대한 약리작용(藥理作用))

  • Ro, Jai-Youl;Lee, Woo-Choo
    • The Korean Journal of Pharmacology
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    • v.11 no.2
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    • pp.9-17
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    • 1975
  • The adrenergic blocking activity and refractory period of cardiac muscle on isolated rabbit atria were measured after administration of Scutellaria. In rabbits and cats the antiarrhythmic action of Scutellaria on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined and also compared with that of propranolol and quinidine. The alcoholic extract of Scutellaria produced a marked decrease in heart rate and contractile amplitude of the isolated rabbit atria. Pretreatment with Scutellaria rendered the atria to fail to respond to epinephrine, indicating that this crude drug possesses an adrenergic blocking activity. The extract produced a marked prolongation of the refractory period of atrial muscle. The extract effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria. As propranolol and quinidine it also suppressed the atrial arrhythmia induced by ouabain. The extract prevented, as propranolol and quinidine, the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, the alcoholic extract of Scutellaria exerted some suppressive effect in anesthetized rabbits but no effect on cats. From the above results, it may be concluded that Scutellaria is effective against atrial and ventricular arrhythmias. The antiarrhythmic effects of this drug may be the result of adrenergic beta receptor blocking and cardiac depressive activities including prolongation of the refractory period of cardiac muscle.

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Role of endometrial immune cells in implantation

  • Lee, Ji-Yeong;Lee, Millina;Lee, Sung-Ki
    • Clinical and Experimental Reproductive Medicine
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    • v.38 no.3
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    • pp.119-125
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    • 2011
  • Implantation of an embryo occurs during the mid-secretory phase of the menstrual cycle, known as the "implantation window." During this implantation period, there are significant morphologic and functional changes in the endometrium, which is followed by decidualization. Many immune cells, such as dendritic and natural killer (NK) cells, increase in number in this period and early pregnancy. Recent works have revealed that antigen-presenting cells (APCs) and NK cells are involved in vascular remodeling of spiral arteries in the decidua and lack of APCs leads to failure of pregnancy. Paternal and fetal antigens may play a role in the induction of immune tolerance during pregnancy. A balance between effectors (i.e., innate immunity and helper T [Th] 1 and Th17 immunity) and regulators (Th2 cells, regulatory T cells, etc.) is essential for establishment and maintenance of pregnancy. The highly complicated endocrine-immune network works in decidualization of the endometrium and at the fetomaternal interface. We will discuss the role of immune cells in the implantation period and during early pregnancy.

Evaluation of the Herbal Extract Mixture for the Effects of Hair-Regrowth Compared to 3% Minoxidil; Elongation of Anagen Period on C3H Mice (모발생장기 유도 C3H 생쥐에 있어서 미녹시딜과 생약추출 혼합 조성물의 모발 재성장 유도 효능)

  • 이계호;한선일;박길흥;권영이
    • YAKHAK HOEJI
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    • v.47 no.1
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    • pp.14-19
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    • 2003
  • The hair cycle consists of three phases, growth (anagen), involution (catagen) and quiescence (telogen) phases. In order to evaluate hair re-growth effect of herbal extracts mixture containing the 70% ethanol extracts of Polygoni Multiflori Radix, Mori Cortex Radicis, Gingko Biloba Folium and Pine bud, we have examined the induction of the anagen phase and/or elongation of the anagen period using C3H mice. Morphological examination was done by Hattori' and Ogawa's method. Enzyme activities of ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and alkaline phosphatase (ALP) was detected by Bessey-Lovry-Brock's method. Enzyme activity as a biochemical marker of hair cycle was investigated in the third hair cycle period of C3H mice after depilation. 3% Minoxidil treated group and herbal extract mixture treated group were shown 3 days earlier initiation of anagen than control group. In cycling mouse skin, ${\gamma}$-GT activity is pronounced during anagen and greatly diminished during telogen. Herbal extract mixture has shown promising hair re-growth effect on hair follicular cycles of C3H mice.

Effects of HR-AC Techniques and Kinesio Taping on Pain Changes in Delayed Onset Muscle Soreness (지연성근육통에 적용한 HR-AC기법과 키네시오 테이핑이 통증 변화에 미치는 영향)

  • Bae, Sea-hyun;Kim, Kyung-yoon
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.26 no.2
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    • pp.1-10
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    • 2020
  • Background: This study aimed to investigate the effect of hold-relax and antagonist contraction (HR-AC) technique and Kinesio taping on pain changes in delayed-onset muscle soreness (DOMS) of 20's adults. Methods: Based on voluntary participation, 14 participants with induced-DOMS were randomly divided into control (non-treatment, n=7) and experiment group (HR-AC technique and kinesio taping, n=7). Measurement were used visual analogue scale (VAS), heart rate variability (HRV), and brain wave (alpha). There were 5 sets of the HR-AC technique application on the 5th day from the day of DOMS induction (rest for 30s between sets). Kinesio taping was applied to the same area after HR-AC. Results: The VAS showed significant changes according to the period and in the interaction between the period and the group (p<.01). HRV and alpha wave (Fp1) showed significant changes according to the period (p<.001). The analgesic effect was more rapid and continuous in the experimental group than in the control group. Conclusion: This study showed that the HR-AC technique and Kinesio taping are effective interventions for the management of pain and stress caused by DOMS.

An Analysis of 2nd Grade Students' Interaction in the Classification Activities of LTTS Program (LTTS 분류 활동에서 나타난 초등학교 2학년 학생들의 상호 작용 분석)

  • Kim, Sun-Ja;Shin, Jae-Sop;Park, Jong-Wook
    • Journal of Korean Elementary Science Education
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    • v.26 no.4
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    • pp.395-406
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    • 2007
  • The purpose of this study was to investigate the characteristics of 2nd grade students' interaction in the classification activities of LTTS. For the purposes of this study, three heterogeneous groups, chosen by cognitive level, were selected. The students' interactions were audio/video taped and classified as either cognitive or affective interaction. The results of this study are as follows. In the cognitive interactions, the frequency and quality of the functions of 'questions' and 'making suggestions' were higher than those of 'Responses' and 'Receiving opinions'. In the affective interactions, the frequency of 'induction' and 'dissatisfaction' was higher than that of the other types. The frequency and quality of interactions of students in both the early and mid concrete stage were higher than those of students in the transitional stage. Qualitatively higher-level interactions such as 'making suggestions' and positive interactions such as 'induction' to induce students who were passive in activities were made by the students at higher cognitive levels. However, the low-level of interaction in suggesting their opinion to the constituent's suggestion and 'dissatisfaction' with student in transition period who were passive in activity influenced group working negatively.

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Studies of the Radiation Effects on Mouse Germ Cell (방사선(放射線)이 생쥐생식세포(生殖細胞)에 미치는 영향(影響)에 관(關)한 연구(硏究))

  • Chung, Kyu-Hoi;Chun, Ki-Jung;Chung, Hai-Won;Yoo, Byung-Sun;Lee, Jeong-Ho
    • Journal of Radiation Protection and Research
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    • v.10 no.1
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    • pp.29-40
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    • 1985
  • The objectives of present study is to investigate genetic damage of radiation in mammalian male germ cell and. to establish available screening method for determining genetic hazard by radiation. Several methods were employed to measure the genetic damage of radiation as follows: Sperm head counts, frequency occurrence of sperm with abnormal head shape, fertility, activity of LDH-X, and the induction of unscheduled DNA synthesis (U.D.S.) in male mouse were performed with the passing of time after irradiation by making use of the sequence of event that occurs during spermatogenesis. Sperm head counts and activity of LDH-X in testes were gradually reduced by increased radiation dose and with the passing of the time after irradiation. Frequency occurrence of sperm with abnormal head shape, sterile period, and the induction of unscheduled DNA synthesis were increased by increased radiation dose. It is suggested that since germ cell is a direct reflection of genetic complement, the use of male germ cell is rapid and convenient method for measuring genetic damage by radiation.

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Mechanical Synthesis and Rapid Consolidation of Nanostructured W-Al2O3 Composite

  • Lee, BooRak;Jeong, GeolChae;Park, GeunO;Shon, In-Jin
    • Korean Journal of Materials Research
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    • v.28 no.6
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    • pp.343-348
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    • 2018
  • Recently, the properties of nanostructured materials as advanced engineering materials have received great attention. These properties include fracture toughness and a high degree of hardness. To hinder grain growth during sintering, it is necessary to fabricate nanostructured materials. In this respect, a high-frequency induction-heated sintering method has been presented as an effective technique for making nanostructured materials at a lower temperature in a very short heating period. Nanopowders of W and $Al_2O_3$ are synthesized from $WO_3$ and Al powders during high-energy ball milling. Highly dense nanostructured $W-Al_2O_3$ composites are made within three minutes by high-frequency induction-heated sintering method and materials are evaluated in terms of hardness, fracture toughness, and microstructure. The hardness and fracture toughness of the composite are $1364kg/mm^2$ and $7.1MPa{\cdot}m^{1/2}$, respectively. Fracture toughness of nanostructured $W-Al_2O_3$ is higher than that of monolithic $Al_2O_3$. The hardness of this composite is higher than that of monolithic W.