• Title/Summary/Keyword: $^6Li\

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Mechanism of Catecholamine Secretion Evoked by Lithium from the Isolated Perfused Rat Adrenal Gland (흰쥐 적출관류부신에서 리튬에 의한 카테콜아민 분비작용의 기전)

  • Lim, Dong-Yoon;Kim, Cheol;Oh, Hyeong-Geun
    • The Korean Journal of Pharmacology
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    • v.32 no.3
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    • pp.357-371
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    • 1996
  • Lithium (Li) is known to be used not only during acute manic psychosis but also acute depressive phase in manic-depression. In the present study, it was attempted to investigate the effect of lithium on catecholamine (CA) secretion from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. Replacement of $Na^+$ (118.4 mM) by lithium in the normal Krebs-bicarbonate solution used to perfuse the gland produced gradually an increased response in the spontaneous catecholamine release, which was peaked at $30{\sim}60$ min after its perfusion. Li-Krebs solution was perfused into an adrenal vein for 2 hours in every experiments. Li-Krebs-evoked CA secretory responses were depressed significantly under loading with $Ca^{++}-free$ medium. This CA secretion evoked by lithium loading was also reduced markedly by the pretreatment with nicardipine ($10^{-6}$ M), TMB-8 ($10^{-5}$ M) and chlorisondamine ($10^{-6}$ M) for 20 min, respectively, while was not affected by preloading with a pirenzepine ($2{\times}10^{-6}$ M)-containing Krebs. $Na^+$ pump inhibition by pretreatment with ouabain ($10^{-4}$ M) for 20 min did make the marked depression in Li-evoked CA secretory responses. Moreover, Li-evoked CA release was also diminished markedly by preloading with tetrodotoxin ($5{\times}10^{-7}$ M)-contaming Krebs for 20 min. All these experimental results taken together suggest that lithium enhances CA secretion in a $Ca^{++}$-dependent fashion by its accumulation in the adrenomedullary chromaffin cells of the rat, and that this secretory effect may be meidated by a dual mechanism: (i) chromaffin cell depolarization and subsequent opening of voltage-sensitive $Ca^{++}$ channels and (ii) activation of a $[Li]_i-[Ca]_0$ counter-transport system.

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Effect of Acute Unilateral Ureteral Obstruction on Handling of $Li^+$ by Contralateral Kidney in Rabbits (급성 일측 수뇨관 폐쇄후 상대신의 $Li^+$처리에 관한 연구)

  • Sung, Ho-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology
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    • v.16 no.2
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    • pp.165-175
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    • 1982
  • Changes in handling of $Li^+$ by contralateral kidney during acute $Li^+$ loading were investigated immediately after unilateral ureteral obstruction. Carotid artery, jugular vein, renal vein and ureter of experimental animal were catheterized and renal venous flow was shunted to .external jugular vein. In experimental group right ureter was ligated. One to two hours after operation a single shot of LiCl solution (2 mEq/kg) was intravenously injected and then .arterial, renal venous blood and urine samples were taken sequentially for 1 to $1{\frac{1}{2}}$ hours. Urine volume, plasma and urinary concentrations of $Li^+$, $Na^+$ and $K^+$ were measured and urinary excretion of them were calculated. Results obtained were as follows: 1) In experimental group urine volume, urinary excretion of $Na^+$, and $K^+$ by contralateral kidney after unilateral ureteral obstruction were slightly larger than mean value of both kidney in control group. 2) During acute $Li^+$ loading contralateral kidney in experimental group showed limited $K^+$ excretion, but urinary flow and $Na^+$ excretion were comparable to mean value of both kidney in control group. 3) Urinary osmolar concentration in experimental group was much lower than that in control group, and it was maintained at low level even after Li loading. 4) In experimental group plasma$Li^+$ concentration decreased more slowly than in control group after a single shot of LiCl solution. 5) Urinary excretion of $Li^+$ in experimental group was markedly decreased, even lesseer than mean of both kidney in control group. 6) From the above results it was concluded that immediately after unilateral ureteral obstruction contralateral kidney showed normal water and $Na^+$ diuretic response to Li load but urinay $Li^+$ excretion was decreased and reclaimed $Li^+$ to systemic circulation.

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Stage transformation characteristice of Li, K and Na-graphite intercalation compounds (Li, K과 Na-흑연 층간화합물의 stage 전이특성)

  • 오원춘;임창성;오근호;고영신
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.1
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    • pp.83-90
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    • 1998
  • Stage transformation characteristics of Li, K and Na-graphite deintercalation compounds (GDICs) were studied under consideration of a deintercalation mechanism of the intercalants between carbon layers. Li-graphite intercalation compounds (GICs) synthesized by a controlling temperatures and pressures have been spontaneously decomposed in the atmosphere. By X-ray differaction analysis the $d_{001}$-values of stage 1 and 2 were identified to be 3.71 and 7.06 $\AA$, respectively. After 6 weeks, the deintercalation reaction of the Li-GICs ceased and only residual compounds could be observed. K-GICs were synthesized by the modified two-bulb method resulting in structural stabilities and stage transitions. By X-ray diffraction analysis the very stable K-graphite residue compounds were observed after 10 weeks. Na-GICs with stage 1 and 2 were synthesized using the high temperature and pressure technique. The temperature dependence of a deintercalation reaction and a thermal stability of Na-GICs were discussed. The structure changes of the Na-GDICs depending on heating rates were identified by X-ray diffraction. According to the deintercalation process, the stage transformations could be attributed to irregular deintercalations of the GDICs with disordered stage.

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Sintering Properties of the $Mg_5Ta_4O_{15}$ Ceramics with $Li_2CO_3$ Additions ($Li_2CO_3$ 첨가에 따른 $Mg_5Ta_4O_{15}$ 세라믹스의 소결 특성)

  • Kim, Jae-Sik;Choi, Eui-Sun;Ryu, Ki-Won;Lee, Young-Hie
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.175-176
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    • 2008
  • In this study, the sintering properties and structural properties of the $Mg_5Ta_4O_{15}$cation-deficient perovskite ceramics with $Li_2CO_3$ additions are investigated. The cation-deficient perovskite ceramics are prepared through the solid-state route. According to the XRD pattern, $Mg_4Ta_2O_9$, $MgTa_2O_6$ and $Mg_5Ta_4O_{15}$ phase existed in sintered pure $Mg_5Ta_4O_{15}$ ceramics. With $Li_2CO_3$, additions, the peak intensities of $Mg_4Ta_2O_9$ and $MgTa_2O_6$ phase were reduced. Also, diffraction intensity of the $Mg_5Ta_4O_{15}$ phase was increased with increments of $Li_2CO_3$ additions. The bulk densities were increased with increasing of $Li_2CO_3$ amount and approach the theoretical density of the $Mg_5Ta_4O_{15}$ ceramics, more and more. Microstructure of the $Mg_5Ta_4O_{15}$ ceramics were densified more and more by additions of $Li_2CO_3$. The bulk density of $Mg_5Ta_4O_{15}$+5wt% $Li_2CO_3$ ceramics sintered at $1500^{\circ}C$ for 10 hours was $5.88g/cm^3$.

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Synthesis and Electrochemical Characteristics of Li4Ti5O12 Nanofibers by Hydrothermal Method (수열법에 의한 Li4Ti5O12 Nanofibers 합성 및 전기화학적 특성에 관한 연구)

  • Kim, Eun-Kyung;Choi, Byung-Hyun;Jee, Mi-Jung;Kwon, Yong-Jin;Seo, Han;Kim, Young-Jun;Kim, Kwang-Bum
    • Journal of the Korean Ceramic Society
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    • v.47 no.6
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    • pp.627-632
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    • 2010
  • In this paper the effect of the structure, particle size, morphology of nanofibers and nanoparticles for the electrochemical characteristics of $Li_4Ti_5O_{12}$ was investigated. The $H_2Ti_2O_5{\cdot}H_2O$ synthesized in hydrothermal treatment from a NaOH treatment on $TiO_2$ by ion exchange processing with HCl solutions. After the $Li_4Ti_5O_{12}$ nanofibers synthesized in hydrothermal treatment of $H_2Ti_2O_5{\cdot}H_2O$ and $LiOH{\cdot}H_2O$. The hydrogen titanate precursor prepared by ion exchange processing with 0.1~0.3M HCl solutions and the final products calcined at $350^{\circ}C{\sim}400^{\circ}C$. The $Li_4Ti_5O_{12}$ nanofibers showed well reversibility during the insertion and extraction of Li, good cycle performance, high capacity and low electrochemical reaction resistance than nanoparticles. also c-rate exhibited a discharge capacity of 172 mAh/g at 0.2C and 115mAh/g at 5C, which is the 77%, 67% of that obtained in the process charged, discharged at 0.2C.

Analysis of Factors Influencing the Measurement Error of Ground-based LiDAR (지상기반 라이다의 측정 오차에 영향을 미치는 요인 분석)

  • Kang, Dong-Bum;Huh, Jong-Chul;Ko, Kyung-Nam
    • Journal of the Korean Solar Energy Society
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    • v.37 no.6
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    • pp.25-37
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    • 2017
  • A study on factors influencing measurement error of Ground-based LiDAR(Light Detection And Ranging) system was conducted in Kimnyeong wind turbine test site on Jeju Island. Three properties of wind including inclined angle, turbulence intensity and power law exponent were taken into account as factors influencing the measurement error of Ground-based LiDAR. In order to calculate LiDAR measurements error, 2.5-month wind speed data collected from LiDAR (WindCube v2) were compared with concurrent data from the anemometer on a nearby 120m-high meteorological mast. In addition, data filtering was performed and its filtering criteria was based on the findings at previous researches. As a result, at 100m above ground level, absolute LiDAR error rate with absolute inclined angle showed 4.58~13.40% and 0.77 of the coefficients of determination, $R^2$. That with turbulence intensity showed 3.58~23.94% and 0.93 of $R^2$ while that with power law exponent showed 4.71~9.53% and 0.41 of $R^2$. Therefore, it was confirmed that the LiDAR measurement error was highly affected by inclined angle and turbulence intensity, while that did not much depend on power law exponent.

Recovery of Li from the Lithium Containing Waste Solution by D2EHPA (리튬함유 폐액으로부터 D2EHPA에 의한 리튬의 회수)

  • Ahn, Hyo-Jin;Ahn, Jae-Woo;Lee, Ki-Woong;Son, Hyun-Tae
    • Resources Recycling
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    • v.23 no.5
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    • pp.21-27
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    • 2014
  • A study on the solvent extraction for the recovery of Li from lithium-containing waste solution was investigated using $D_2EHPA$ as an extractant. The experimental parameters, such as the pH of the aqueous solution, concentration of extractant and phase ratio were observed. Experimental results showed that the extraction percentage of Li was increased with increasing the equilibrium pH. More than 50% of Li was extracted in eq. pH 6.0 by 20% $D_2EHPA$. From the analysis of McCabe-Thiele diagram, 95% of Li was extracted by four extraction stage at phase ratio(O/A) of 3.0. Stripping of Li from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 90 ~ 120 g/L of $H_2SO_4$ was effective for the stripping of Li. Finially, Li was concentrated about 11.85 g/L by continuous stripping process, and then lithium carbonate was prepared by precipitation method.

Figures of Merit of (K,Na,Li)(Nb,Ta)O3 Ceramics with Various Li Contents for a Piezoelectric Energy Harvester

  • Go, Su Hwan;Kim, Dae Su;Han, Seung Ho;Kang, Hyung-Won;Lee, Hyeung-Gyu;Cheon, Chae Il
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.530-534
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    • 2017
  • The figures of merit in the on-resonance and off-resonance conditions ($FOM_{on}$ and $FOM_{off}$) for the piezoelectric energy harvester (PEH) were measured and compared in $[(K_{0.485}Na_{0.515})_{1-X}Li_X](Nb_{0.99}Ta_{0.01})O_3$ (x = 0.04 ~ 0.09) (KNLNT) ceramics with various Li contents. The crystal structure of CuO-doped KNLNT ceramics changes from orthorhombic to tetragonal around the Li fraction of 0.065. The stable temperature range for the tetragonal phase widens to both higher and lower temperatures as Li is substituted. The piezoelectric charge constant ($d_{33}$), electromechanical coupling factor ($k_p$) and mechanical quality factor ($Q_m$) have maximum values at the Li fraction between 0.055 and 0.065 where the phase boundary lies between the orthorhombic and tetragonal phases. Both $FOM_{on}$ and $FOM_{off}$ have peak values around the phase boundary but the peak compositions are not exactly coincided. The optimal Li fraction in the KNLNT ceramic for a PEH application was found to be between 0.055 and 0.065.

A Study on the Li5Fe5O8 Species Affecting the Microwave Heating Performance on the Ternary Li-Fe-Zn Material (3원계 금속산화물로 제조한 마이크로웨이브 발열소재상 Li5Fe5O8 종이 발열성능에 미치는 영향 연구)

  • Jang, Young Hee;Lee, Sang Moon;Kim, Sung Su
    • Applied Chemistry for Engineering
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    • v.29 no.6
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    • pp.703-709
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    • 2018
  • Dielectric heating materials were prepared through the thermal treatment for composites of Li and Zn type precursors that are major materials being responded to microwave under diversified conditions. The prepared heating material samples were analyzed by SEM and it was confirmed that $Li_5Fe_5O_8$ materials being formed on the surface was a major influencing factor for the heating performance. Heating materials improved the moisture removal in a sludge drying facility, for example, the moisture content of 25 v/v% sludge decreased to 15.22 v/v%. Accordingly, heating materials were confirmed to directly affect the performance and efficiency of the microwave drying process.

Pragmatic Combinations of Acupuncture Points for Lateral Epicondylalgia are Unreliable in the Physiotherapy Setting

  • Alvim, Danielle T.;Ferreira, Arthur S.
    • Journal of Acupuncture & Meridian Studies
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    • v.11 no.6
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    • pp.367-374
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    • 2018
  • This study describes the reliability of pragmatic combinations of acupuncture points for lateral epicondylalgia (LE) as prescribed by physiotherapists who were experts in acupuncture. Raters (n = 14; 33-59 years) independently prescribed acupuncture points for 30 simulated human patients with LE who were surveyed via a printed questionnaire. The frequency and cooccurrence of acupuncture points prescribed for patients with lateral epicondylitis were assessed. Absolute agreement and Light's kappa (${\kappa}_{Light}$) with 95% confidence interval (CI) were used to quantify the interrater agreement. Raters prescribed 103 unique acupuncture points in different combinations with a median (min-max) of 5 (0-11) acupuncture points. The most prescribed acupuncture point was LI-11 (297 of 420; 71%), and the most common cooccurring acupuncture points were LI-11 and LI-4 (160 of 420; 38%). The absolute agreement for prescribing the acupuncture points ranged from 70% (point GB-20) to 0% (points LI-10, SP-6, LI-11, GB-34, LI-12, and LI-4). Point LR-3 showed the highest interrater reliability for prescribing the acupuncture points [${\kappa}_{Light}=0.112$, 95% CI = (0.055-0.194)], whereas point LI-4 showed the lowest reliability [${\kappa}_{Light}=-0.003$, 95% CI = (-0.024 to 0.024)]. These findings suggest that pragmatic prescriptions of acupuncture points for LE are unreliable among physiotherapists who are experts in acupuncture. Explicit, high-level evidence-based rules for prescribing and teaching combinations of acupuncture points for LE are warranted.