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Effects of α1-adrenoceptor stimulation on ventricular electrophysiological properties of guinea pigs (기니픽 심근의 전기생리학적 특성에 미치는 α1-Adrenoceptor 자극효과)

  • Kim, Jin-sang
    • Korean Journal of Veterinary Research
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    • v.33 no.2
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    • pp.199-209
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    • 1993
  • The effects of ${\alpha}_1$-adrenergic stimulation on membrane potential, intracellular sodium activity $(a_N{^i{_a}})$, and contractility were investigated in the isolated papillary muscle of euthyroid, hyperthyroid, and hypothyroid guinea pigs. Cardiac alterations in the thyroid state have been shown to induce marked changes in action potential characteristics, the most pronounced shortening of action potential duration by hyperthyroidism and an increase in duration by hypothyroidism. $10^{-5}M$ Phenylephrine produced a decrease in $(a_N{^i{_a}})$ in euthyroid and hypothyroid preparations, but an increase in $(a_N{^i{_a}})$ in hyperthyroid ones. The major findings were that phenylephrine produced a stronger positive inotropic effect(PIE) without initial negative inotropic effect(NIE) in hyperthyroid preparations, while phenylephrine produced markedly NIE in hypothyroid ones. The alterations in membrane potential, $(a_N{^i{_a}})$, and contractility were abolished by $3{\times}10^{-5}M$ prazosin in hypothyroidism. In hypothyroid ventricular muscle, the decrease in $(a_N{^i{_a}})$ caused by phenylephrine were not abolished or reduced by $10^{-5}M$ strophanthidin, $10^{-5}M$ TTX, $3{\times}10^{-4}M$ lidocaine, or $100^{-5}M$ verapamil. These results indicate that the ${\alpha}_1$-adrenoceptor-mediated decrease in $(a_N{^i{_a}})$ is not associated with a stimulation of the $Na^+$-$K^+$ pump, inhibition of the $Na^+$ or $Ca^+$ channel in hypothyroid ventricular muscle. $10^{-5}M$ Phenylephrine decreased $(a_N{^i{_a}})$ but increased $(a_N{^i{_a}})$ in the presence of a PKC activator phorbol dibutyrate$(PDB_u)$. In conclusion, it is suggested that the following sequence of events in response to phenyleplhane occur in guinea pig ventricular muscle. First, changes in thyroid state may contribute to the ventacular electrophysiological propeties or ion transport system. Second, the adrenoceptor-mediated initial transient NIE may be associated with the decrease in $(a_N{^i{_a}})$ by PKC activation.

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Pharmacokinetic profiles of levofloxacin after intravenous, intramuscular and subcutaneous administration to rabbits (Oryctolagus cuniculus)

  • Sitovs, Andrejs;Voiko, Laura;Kustovs, Dmitrijs;Kovalcuka, Liga;Bandere, Dace;Purvina, Santa;Giorgi, Mario
    • Journal of Veterinary Science
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    • v.21 no.2
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    • pp.32.1-32.13
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    • 2020
  • Levofloxacin pharmacokinetic profiles were evaluated in 6 healthy female rabbits after intravenous (I/V), intramuscular (I/M), or subcutaneous (S/C) administration routes at a single dose of 5 mg/kg in a 3 × 3 cross-over study. Plasma levofloxacin concentrations were detected using a validated Ultra Performance Liquid Chromatography method with a fluorescence detector. Levofloxacin was quantifiable up to 10 h post-drug administration. Mean AUC0-last values of 9.03 ± 2.66, 9.07 ± 1.80, and 9.28 ± 1.56 mg/h*L were obtained via I/V, I/M, and S/C, respectively. Plasma clearance was 0.6 mL/g*h after I/V administration. Peak plasma concentrations using the I/M and S/C routes were 3.33 ± 0.39 and 2.91 ± 0.56 ㎍/mL. Bioavailability values, after extravascular administration were complete, - 105% ± 27% (I/M) and 118% ± 40% (S/C). Average extraction ratio of levofloxacin after I/V administration was 7%. Additionally, levofloxacin administration effects on tear production and osmolarity were evaluated. Tear osmolarity decreased within 48 h post-drug administration. All 3 levofloxacin administration routes produced similar pharmacokinetic profiles. The studied dose is unlikely to be effective in rabbits; however, it was calculated that a daily dose of 29 mg/kg appears effective for I/V administration for pathogens with MIC < 0.5 ㎍/mL.

The Spin-Rotation Interaction of the Proton and the Fluorine Nucleus in the Tetrahedral Spherical Top Molecules

  • Lee, Sang-Soo;Ozier, Irving;Ramsey, N.F.
    • Nuclear Engineering and Technology
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    • v.5 no.1
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    • pp.38-43
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    • 1973
  • The spin-rotation constants of the proton and tile fluorine nucleus in C $H_4$, Si $H_4$, Ge $H_4$, C $F_4$, Si $F_4$ and Ge $F_4$ were determined experimentally by the molecular beam magnetic resonance method. From the Hamiltonian and the high field approximation, the quantized energy level is given by the following equation. W $m_{I}$ $m_{J}$=- $g_{I}$ $m_{I}$H- $g_{J}$ $m_{J}$H- $C_{av}$ $m_{I}$ $m_{J}$, where $c_{av}$ is one third of the trace of the C tensor. In the nuclear resonance experiment, the proton and the fluorine nuclear resonance curves consist of many unresolved lines given by v=- $g_{J}$H- $C_{av}$ $m_{I}$, and a Gaussian approximation is made to correlate $c_{av}$ to the experimentally obtained half-width of the resonance curve. In the rotational resonance experiment, the five resonance peaks as predicted by v=- $g_{I}$H- $c_{av}$ $m_{I}$, $m_{I}$=0, $\pm$1 and $\pm$2, were all observed. The magnitude of car was determined by measuring the frequency distance between two adjacent peaks. The sign of $c_{av}$ was determined by the side peak suppression technique. The technique is described, and the sign and magnitude of the spin-rotation constant cav are summarized as following: for C $H_4$ -10.3$\pm$0.4tHz(from the rotational resonance), for SiH +3.71$\pm$0.08kHz(from the nuclear resonance), for Ge $H_4$+3.79$\pm$0.13kHz(from the nuclear resonance), for C $F_4$, -6.81$\pm$0.08kHz(from the rotational resonance), for Si $F_4$, -2.46$\pm$0.06kHz(from the rotational resonance), and finally for Ge $F_4$-1.84$\pm$0.04kHz(from the rotational resonance).onal resonance).esonance).

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APPROXIMATION OF CUBIC MAPPINGS WITH n-VARIABLES IN β-NORMED LEFT BANACH MODULE ON BANACH ALGEBRAS

  • Gordji, Majid Eshaghi;Khodaei, Hamid;Najati, Abbas
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.5
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    • pp.1063-1078
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    • 2011
  • Let M = {1, 2, ${\ldots}$, n} and let V = {$I{\subseteq}M:1{\in}I$}. Denote M\I by $I^c$ for $I{\in}V$. The goal of this paper is to investigate the solution and the stability using the alternative fixed point of generalized cubic functional equation $ \sum\limits_{I{\in}V}f(\sum\limits_{i{\in}I}a_ix_i-\sum\limits_{i{\in}I^c}a_ix_i)=2{^{n-2}{a_1}}\sum\limits_{i=2}^na_i^2[f(x_1+x_i)+f(x_1-x_i)]+2{^{n-1}{a_1}(a^2_1-\sum\limits_{i=2}^2a^2_i)f(x_1)$ in ${\beta}$-Banach modules on Banach algebras, where $a_1,{\ldots},a_n{\in}\mathbb{Z}{\backslash}\{0\}$ with $a_1{\neq}={\pm}1$ and $a_n=1$.

Detection of Silent Allele at Esterase(Es) Locus in Jeju Native Horse (제주마에서 Esterase(Es) locus의 silent allele 검출)

  • 조길재;조병욱;강한석;김용균
    • Journal of Life Science
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    • v.13 no.4
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    • pp.412-415
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    • 2003
  • The purpose of this present study was to investigate the polymorphism of esterase locus for individual identification and parentage verification in Jeju native horse (JNH). Seventy three random JNH samples were studied by polyacrylamide gel isoelectric focusing(IEF) at pH 3.5 ∼ 6.0. We detected international recognized alleles, F, G, H, I, M, and an silent allele $I^o$. Gene frequencies of allele I showed 0.479 the highest, while allele H and M($I^o$) with relatively low frequencies were 0.027 and 0.014, respectively.

Increase of Intracellular $Ca^{2+}$ Concentration by Vibrio Vulnificus Cytolysin in Rat Platelets; Triggering Mechanism of Platelet Cytolysis

  • Park, Jin-Bong;Chae, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.2
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    • pp.199-205
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    • 1999
  • Vibrio vulnificus cytolysin caused platelet cytolysis and increased intracellular calcium concentration $([Ca^{2+}]_i)$ of rat platelets in a concentration-dependent manner. In the presence of V. vulnificus cytolysin (3 HU/ml), lactate dehydrogenase (LDH) activity was increased from $1.3{\pm}0.4%$ of control to $64.3{\pm}3.4%$ in platelet suspension buffer. In $Ca^{2+}-free$ platelet suspension buffer, however, V. vulnificus cytolysin did not induce $[Ca^{2+}]_i$ increase and LDH release. Addition of EGTA (2 mM) to suspension buffer after the initial $Ca^{2+}$ influx reversed $[Ca^{2+}]_i$ to the control level. However, a $Ca^{2+}$ channel blocker verapamil $(20\;{\mu}M)$ or mefenamic acid $(20\;{\mu}M)$ did not inhibit V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. Divalent cations such as $Co^{2+},\;Cd^{2+}\;or\;Mn^{2+}$ (2 mM each) also did not alter V. vulnificus cytolysin-induced $[Ca^{2+}]_i$ increase and LDH release. V. vulnificus cytolysin (3 HU/ml)-induced calcium influx was completely blocked by lanthanum (2 mM). Lanthanum (2 mM) also completely blocked V. vulnificus cytolysin (3 HU/ml)-induced LDH release. Osmotic protectants such as, raffinose, sucrose or PEG600 (50 mM each) did not inhibit the lytic activity of V. vulnificus cytolysin. In conclusion, lanthanum sensitive $Ca^{2+}$ influx plays a significant role in Vibrio vulnificus cytolysin-induced platelet cytolysis and thrombocytopenia in V. vulnificus infection.

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Vegetation Structure Analysis and Ecological Distance of Pinus densiflora Community in Chayang-chon Area, Soraksan National Park (설악산국립공원 자양천지역 소나무림 군집구조 및 생육거리)

  • 이경재;한봉호;이옥하
    • Korean Journal of Environment and Ecology
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    • v.11 no.4
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    • pp.493-505
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    • 1998
  • To study vegetation structure and distance between trees of Pinus densiflora forest in Chayang-chon area, Soraksan National Park, thirty-nine plots(10m$\times$10m) were established. They were classified into two communities by TWINSPAN and DCA technique. In the Community I, P. densiflora(DBH 35~75cm, height 9~16m, age 60~80) dominated in canopy and were predicted to be changed by deciduous broad-leaved trees also. In the Community II, P. densiflora(DBH 9~26.5cm, height 9~16m, age 30~50m) dominated in canopy. It seemed that the community II would maintain P. densiflora community for a long time since P. densiflora dominated in both canopy and understory. Shonnon's diversity index was higher in the community II(1.4247) than in the community I(1.2978). The distantes between canopy trees were 4.92$\pm $2.14m in the community I and 2.41$\pm $0.97m in the community II. The regression between DBH in canpy and ecological distance was Y(Distance) = 0.06355$\times $(DBH)+1.51613.

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A Study on a Method for Computing the Powers and Inverses in GF($2^m$) (GF($2^m$) 상의 누승 및 역원을 구하는 방법에 관한 연구)

  • Park, Yong-Joon;Kang, Sung-Su;Kim, Heung-Soo
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1191-1194
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    • 1987
  • This paper presents a method for computing the powers and inverse of an element in GF($2^m$). This method is based on the squaring algorithm $A^2=\sum\limits_{i=0}^{2m-2}P_i$, where $Pi={\alpha}_{i/2}$ if i is even, Pi=0 otherwise, derived from the multiplication algorithm for two elements in GF($2^m$). The powers and inverses in GF($2^m$) for m=2, 3, 4,5 were obtained using computer program, and used in circuit realization of Galois switching function. The squaring and inverse generating circuits are also shown.

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A SOLUTION OF EGGERT'S CONJECTURE IN SPECIAL CASES

  • KIM, SEGYEONG;PARK, JONG-YOULL
    • Honam Mathematical Journal
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    • v.27 no.3
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    • pp.399-404
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    • 2005
  • Let M be a finite commutative nilpotent algebra over a perfect field k of prime characteristic p and let $M^p$ be the sub-algebra of M generated by $x^p$, $x{\in}M$. Eggert[3] conjectures that $dim_kM{\geq}pdim_kM^p$. In this paper, we show that the conjecture holds for $M=R^+/I$, where $R=k[X_1,\;X_2,\;{\cdots},\;X_t]$ is a polynomial ring with indeterminates $X_1,\;X_2,\;{\cdots},\;X_t$ over k and $R^+$ is the maximal ideal of R generated by $X_1,\;X_2,{\cdots},\;X_t$ and I is a monomial ideal of R containing $X_1^{n_1+1},\;X_2^{n_2+1},\;{\cdots},\;X_t^{n_t+1}$ ($n_i{\geq}0$ for all i).

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