• Title/Summary/Keyword: AaIT

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Modification of Insect Sodium Currents by a Pyrethroid Permethrin and Positive Cooperativity with Scorpion Toxins (피레스로이드계 살충제 퍼메트린이 Heliothis virescens 중추신경세포에 있는 나트륨채널에 작용하는 기작을 전기생리학적으로 연구)

  • Lee, Daewoo;Adams, Michael E.
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.117-128
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    • 2022
  • In this study, we have examined pyrethroid actions on sodium channels in the pest insect Heliothis virescens. The synthetic pyrethroid permethrin increased steady-state sodium current in H. virescens central neurons and prolonged tail currents (INa-tail) due to extreme slowing of sodium channel deactivation. Prolongation of INa-tail was evident at permethrin concentrations as low as 60 nM, which modified ~1.7% of sodium channels and 10 μM permethrin modified about 30% of channels. The average time constant (τ1) of tail current decay was ~335 ms for permethrin-modified channels. These modified channels activated at more negative potentials and showed slower activation kinetics, and failed to inactivate. Permethrin modification of sodium channels was dramatically potentiated by the α scorpion toxin LqhαIT, showing positive cooperativity between two binding sites. The amplitude of the tail current induced by 0.3 μM permethrin was enhanced ~8-fold by LqhαIT (200 pM). Positive cooperativity was also observed between permethrin and the insect-specific scorpion toxin AaIT as 10 nM permethrin potentiated the shift of voltage dependence caused by AaIT (~2-fold).

A study on Relationship between Pattern wafer and Blanket Wafer for STI-CMP (STI-CMP 공정을 위한 Pattern wafer와 Blanket wafer 사이의 특성 연구)

  • 김상용;이경태;김남훈;서용진;김창일;이우선;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.211-213
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    • 1999
  • In this paper, we documented the controlling oxide removal amount on the pattern wafer using removal rate and removal thickness of blanket wafer. There was the strong correlation relationship for both(correlation factor:0.7109). So, we could confirm the repeatability as applying for STI CMP process from the obtained linear formular. As the result of repeatability test, the difference of calculated polishing time and actual polishing time was 3.48 seconds based on total 50 lots. If this time is converted into the thickness, it is from 104$\AA$ to 167$\AA$. It is possible to be ignored because it is under the process margin.

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Design of a Highly Linear Broadband Active Antenna Using a Multi-Stage Amplifier (다중 증폭 회로를 이용한 높은 선형 특성을 갖는 광대역 능동 안테나 설계)

  • Lee, Cheol-Soo;Jung, Geoun-Seok;Pack, Jeong-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.11
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    • pp.1193-1203
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    • 2008
  • An active antenna(AA) can have wider bandwidth and more gain with small antenna size than those of passive antennas. However, AA inherently generates thermal noise and spurious signals from an active device. Moreover, the spurious performance of AA is very important in a highly sensitive receiving system since it is located at the front end of the receiving system. In this study, we developed an AA with $100{\sim}500\;MHz$, having the output P1dB higher than 3 dBm and little spurious signals in real environments. To achieve such performance, we designed an AA with 3-stage amplifier using CD(common drain) FET and 2 BJTs. Its electrical performances were simulated using ADS. The measurement results for typical gain, NF, OIP3, VSWR and P1dB in the required frequency band were 9.7 dBi, 10 dB, 14 dBm, 1.7:1 and 3 dBm respectively. They are in good agreement with simulation results. The unwanted spectrum level of the proposed AA is $10{\sim}30\;dB$ lower than that of the antenna with CS(common source) FET configuration at a west suburban area of Seoul, which shows that the proposed AA can be applicable to a highly sensitive receiving system for detecting unknown weak signals mixed with broadcasting and civilian communication signals.

Advance Understanding and New Treatment of Alopecia Areata (원형탈모증(alopecia areata)의 최신 이해와 치료)

  • Kang, Kyung-Hwa
    • Journal of Life Science
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    • v.26 no.11
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    • pp.1345-1354
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    • 2016
  • Alopecia areata (AA) is a common and tissue-specific autoimmune disease of hair follicle resulting in the loss of hair on the scalp and elsewhere on the body. Hair follicles is a unique organ because it has its own immune system and hormonal milieu and has a different immune state at each hair cycle stage. The collapses of anagen-dependent hair follicle immune privilege arise autoimmune attack, inducing ectopic MHC class I expression in the hair follicle epithelium and autoantigen presentation to autoreactive CD8+T cells, which results in AA. Clinical and experimental studies have pointed that psychological stress may also influence the hair follicle immune/hormone systems and contribute to the induction of AA. The key pathogenesis of AA is associated with immune privilege guardians (including ACTH, ${\alpha}-MSH$, and $TGF-{\beta}$), natural killer group 2D-positive (NKG2D+) cells (including NK and CD8+T cells), and stress hormones (including CRH and substance P). Effective treatments for AA are still demanded. One of the future targets of treatment will be the modification of hair follicle immune privilege including stress. Recent studies have reported that JAK inhibitors and immunomodulators used in other autoimmune disease, such as psoriasis, atopic dermatitis, and rheumatoid arthritis, Tregs, platelet-rich plasma therapy, statins, and prostaglandin anaolgues are effective for AA. Here the article reviews the recent understanding in the pathogenesis associated with perifollicular endocrine/immunology and new treatments of AA.

Comparison of Some Physicochemical Properties and Adsorption of Organic Cations between Ca- and Na-bentonites (Ca-형 및 Na-형 벤토나이트의 제반 물성 및 유기양이온 흡착비교)

  • 고상모;김자영
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.4
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    • pp.243-257
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    • 2002
  • Ca-type and Na-type bentonites show the great difference of some physicochemical properties. Na exchanged bentonite is mainly used for the foundry and construction materials in domestic utilization. This study tries to identify in detail the differences of some physicochemical properties and thermal properties between Ca-type and Na-type bentonites. Also the adsorption behavior and interlayer expansion for the HDTMA (Hexadecyltrimethylammonium) exchanged and CP (Cetylprydinium) exchanged Ca-type and Na-type bentonites were compared. Na-type bentonite shows the strong alkaline property, high viscosity and swelling compared to Ca-type bentonite. However, two types are very similar for the cation exchange capacity and MB (Methylene Blue) adsorption. The decomposition of adsorbed and interlayer water of Na-type bentonite is caused in the lower temperature than Ca-type bentonite. And Ca-type bentonite shows the decomposition of structural water in the lower temperature than Na-type bentonite. The interlayer expansion of montmorillonite resulted to the intercalation of HDTMA and CP into bentonite is so strongly caused from 12~15 $\AA$ to $40\AA$ (basal spacing). HDTMA-bentonite is almost expanded to $37~38\AA$ when 200% CEC equivalent amount of HDTMA is added, and CP-bentonite is fullly expanded to 40 $\AA$ in the 140% CEC equivalent amount of CP It means that CP causes the stronger interlayer expansion of montmorillonite and easier adsorption than HDTMA. Adsorption behaviors of CP into bentonite is so stable and continuously sorbed in the proportion to the treatment of amount until 200% of the CEC equivalents. CP-bentonite shows the same adsorption behavior regardless of Ca-type or Na-type montmorillonite.

Development of a Food Freshness Indicator for Monitoring Spoilage of Chicken Breast Using a Porous Substrate (다공성 기재를 이용한 닭가슴살 신선도 인디케이터 제조 및 특성)

  • Lee, Kaeun;Baek, Seunghye;Kim, Dowan;Seo, Jongchul
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.23 no.1
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    • pp.37-45
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    • 2017
  • To visually identify the spoilage of chicken breasts, a three layered freshness indicator consisting of PET/bromocresol green (BCG)-ethylene vinyl acetate (EVA)-acetic acid (AA) composite layer/porous substrates was successfully prepared and their performance were simulated at 20% of $CO_2$ and 4 different trimethylamine (TMA) concentrations to evaluate color change at minimal spoilage level. The visibility and range of color changes of the as-prepared indicators responding to TMA concentration as a simulant were strongly dependent on the concentrations of BCG and AA. As the BCG content increased, the visibility of color change in the freshness indicators was apparently improved and the range of color change could be controlled by contents of AA. Among the as-prepared freshness indicators, 'G0.12_A0.5' which consisting 0.12g of BCG and 0.5g of AA was selected as an optimum composition due to the highest visibility at TMA 20 mg% corresponding to the minimal spoilage level. The color of the indicator changed from yellow to green for spoilage indication of chicken breast, which could be easily seen with the naked eyes and well consistent with the simulation results. It is expected that our developed freshness indicator can be useful in monitoring various food freshness and quality.

Antimicrobial- and Anticarcinogenic Activities of Amphitrite albicostatu Fractions (따개비 분획물의 항균 및 항암 효과)

  • Shin, Hye-Jung;Shin, Mi-Ok
    • Journal of Life Science
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    • v.20 no.10
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    • pp.1505-1510
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    • 2010
  • In this study, we investigated antimicrobial- and anticarcinogenic activities of Amphitrite albicostatu (AA) fractions. AA was extracted with methanol first and then further fractionated into four different types: hexane (AAMH)-, methanol (AAMM)-, buthanol (AAMB)- and aqueous (AAMA) partition layers. In the paper disk test, the antimicrobial activity of AA fractions increased in proportion to concentration. Among the various solvent fractions, only AAMB showed antimicrobial activity. We also determined the growth inhibition and quinone reductase (QR) induced effects of AA fractions on cancer cells. The growth inhibition effects of AA fractions on HepG2 and B16F10 cells were evaluated by MTT assay. AAMM showed the strongest growth inhibition effects on HepG2 and B16F10 cells. The quinine reductase (QR) induced effects of AAMM on HepG2 cells at 100 ug/ml concentration indicated it to be 2.04 times higher than the control values of 1.0. Although further studies are needed, the present work suggests that Amphitrite albicostatu (AA) could have a potential use as a food preservative and chemopreventive agent.

A Study on the Correlation between the Bell's Palsy and the 7-Zone-diagnostic System - Evaluated by the Patterns of Zone 2 of Factor AA - (구안와사와 7구역진단기의 상관성 연구 - Factor AA 제2구역의 유형을 중심으로 -)

  • Cho, Yi-Hyun;Lee, Jin-Bok;Im, Jeong-Gyun;Park, Ka-Young;Yook, Tae-Han;Song, Beom-Yong
    • Journal of Acupuncture Research
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    • v.27 no.2
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    • pp.1-10
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    • 2010
  • Objectives : The 7-zone-diagnostic system is a diagnostic device to predetermine bodily locations by measuring the energy of body. This study was to investigate the relation between the different patterns of Zone 2 of Factor AA in CP-6000A (VEGA, Germany), 7-zone-diagnostic system and the factors of Bell's Palsy. Methods : This study was carried out with the data from factors of Bell's Palsy(age, sex, period after onset, postauricular pain, season which the disease happen, contributing factor). We made three groups according to the different patterns of Zone 2 of Factor AA in CP-6000A. The Factor AA pattern of Group A is that the red bar graph of zone 2 were lower than the normal range. The Factor AA pattern of Group B was that the red bar graph of zone 2 was the normal range. The Factor AA pattern of Group C was that the red bar graph of zone 2 was higher than the normal range. After collecting the data about factors of Bel's Palsy to correspond with conditions of each group were selected, the data was analyzed statistically. Results : The values of number of patient and period after onset of group A was higher than group B and C. The values of ratio of postauricular pain of group B and C was higher than group A. The season of disease happened of group A is spring and winter, group B is winter and group C is summer and autumn. The contributing factor of disease happened of group A is none, and group B and C is stress and clod. Conclusions : In Bell's Palsy, it is thought that the red bar graph of zone 2 is lower, the group have lower energy(虛) and the energy has a character of cold(寒), and zone 2 is higher, the group has the higher energy(實) and the energy has a character of fire(熱).

Carbonation Characteristics of Alkali Activated Blast-Furnace Slag Mortar (알칼리활성 고로슬래그 모르타르의 탄산화 특성)

  • Song, Keum-Il;Yang, Keun-Hyeok;Lee, Bang-Yeon;Song, Jin-Kyu
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.315-322
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    • 2012
  • Alkali-activated slag (AAS) is the most obvious alternative materials that can replace OPC. But, AAS industrial usage as a structural material should be evaluated for its durability. Carbonation resistance is one of the most important factors in durability evaluation. Test results for 18 slag-based mortars activated by sodium silicate and 6 OPC mortars were obtained in this study to verify the carbonation property. Main variables considered in the study were flow, compressive strength before and after carbonation, and carbonation depth. Mineralogical and micro-structural analysis of OPC and AAS specimens prior to and after carbonation was conducted using XRD, TGA, FTIR FE-SEM. Test results showed that CHS was major hydration products of AAS and, unlike OPC, no other hydration products were found. After carbonation, CSH of hydration product in AAS turned into an amorphous silica gel, and alumina compounds was not detected. From the analysis of the results, it was estimated that the micro-structures of CSH in AAS easily collapsed during carbonation. Also, the results showed that this collapse of chemical chain of CSH lowered the compressive strength of concrete after carbonation. By increasing the dosage of activators, carbonation resistance and compressive strength were effectively improved.