• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.61-69
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• 1983

Hypothermia is an essential preparatory procedure for cardiac surgery, which lows the metabolic rate and myocardial oxygen demand. However, hypothermia itself is a stress enough to change the tonus of sympathoadrenal system, especially the cardiovascular responses to the catecholamines. It is reported that the positive chronotropic and inotropic response of catecholamines is exaggerated during hypothermia because of decreased norepinephrine uptake at the junctional cleft or decreased catecholamine metabolism. On the other hand, there are evidences of diminished catecholamines responses in low temperature ana further, interconversion of adrenergic receptors is also suggested. Present investigation was planned to observe the cardiovascular changes and its responses to catecholamines during surface hypothermia in cat. Healthy mongrel cats, weighing $2{\sim}3\;kg$, anesthetized with secobarbital(30 mg/kg), were permitted to hypothermia by external cooling technic. Esophageal temperature, ECG (lead II), heart rate, left ventricular pressure with dP/dt, carotid artery pressure and left ventricular contractile force were monitored with Polygragh (Model 7, Grass), and the respiration was maintained with artificial respirator (V 5 KG, Narco). Followings are summarized results. 1) Surface cooling caused progressive decrease of body temperature and reached $l8.8{\pm}0.8^{\circ}C$ and $16.9{\pm}0.6^{\circ}C$ in 120 and 150 min respectively, after immersion into ice water, and ventricular fibrillation was developed at $20.4{\pm}0.65^{\circ}C$. 2) Heart rate, blood pressure and myocardial contractility were decreased after initial increase as the body temperature falls. 3) Systolic and diastolicdd P/dt of left ventricular pressure were decreased and that the decrement of diastolic dP/dt was more marked. 4) On ECG, ST depression, Twave inversion and prolongation of PR interval were prominent in hypothermia, and moreover, the prolongation of PR interval was marked just prior to the development of ventricular fibrillation. 5) The cardiovascular responses to catecholamines, especially to isoproterenol, were suppressed under hypothermia.

• Journal of Chest Surgery
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• v.28 no.6
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• pp.549-556
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• 1995

We investigated the effects of aprotinin, a protease inhibitor, on isolated rat heart subjected to cardioplegia and global ischemia for 4 hours and then reperfused for 40 minutes. Before ischemia, hearts were perfused with either aprotinin 1x105KIU/L[Aprotinin group,n=8 or no aprotinin[control group,n=8 added to Krebs-Henseleite solution for 30 minutes. Hemodynamic and biochemical parameters such as heart rate, LVP, dP/dt, coronary flow and creatine kinase were measured before cardioplegia and after reperfusion 10,20,30,40 minutes. After completion of experiment, wet and dry heart weight were measured for tissue water and water content evaluation. On reperfusion, recovery of LVP of aprotinin group at each time point was significantly better than that of control group[p<0.05 , and of dP/dt at reperfusion 40 minutes[p=0.034 . No statistically significant differences in heart rate, coronary flow and CK were observed between the two groups, but aprotinin group seemed to have better recovery. No significant differences in tissue water and water content were observed between the two group.These results suggest that pretreatment of aprotinin is effective in myocardial preservation in prolonged hypothermic ischemia and reperfusion.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.9 no.1
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• pp.79-90
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• 2005

In this paper we study the numerical solutions of the stochastic differential equations of the form $$du(x,\;t)=f(x,\;t,\;u)dt\;+\;g(x,\;t,\;u)dW(t)\;+\;\sum\limits_{|q|\leq2m}\;A_q(x,\;t)D^qu(x,\;t)dt$$ where $0\;{\leq}\;t\;{\leq}\;T,\;x\;{\in}\;R^{\nu}$, ($R^{nu}$ is the $\nu$-dimensional Euclidean space). Here $u\;{\in}\;R^n$, W(t) is an n-dimensional Brownian motion, $$f\;:\;R^{n+\nu+1}\;{\rightarrow}\;R^n,\;g\;:\;R^{n+\nu+1}\;{\rightarrow}\;R^{n{\times}n},$$, and $$A_q\;:\;R^{\nu}\;{\times}\;[0,\;T]\;{\rightarrow}\;R^{n{\times}n}$$ where ($A_q,\;|\;q\;|{\leq}\;2m$) is a family of square matrices whose elements are sufficiently smooth functions on $R^{\nu}\;{\times}\;[0,\;T]\;and\;D^q\;=\;D^{q_1}_1_{\ldots}_{\ldots}D^{q_{\nu}}_{\nu},\;D_i\;=\;{\frac{\partial}{\partial_{x_i}}}$.

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.37-41
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• 1984

The $100\%$ of insect pests on the imported logs and Sitophilus oryzae(L.) will be killed both when the imported logs are fumigated on shipboard with 25g methyl $bromide/m^3$ for 24hours at $10\~20^{\circ}C$ and when they are fumigated on shipboard with 37.5g methyl $bromide/m^3$ caculated by DT products for 16 hours at $10\~20^{\circ}C$ using 2 fans of 1800rpm over and ID 30cm. Without using fans, it takes $4\~6$ hours to make gas concentration even in hold. But using 2 fans per hold, the period reduces to $1\~3$ hours.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.237-241
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• 2017

Drought is one of the detrimental factors that impair plant growth and productivity. In this study, we applied annealing control primer (ACP)-based reverse transcriptase PCR (polymerase chain reaction) technique to identify differentially expressed genes (DEGs) in maize leaves in response to drought stress. Two-week-old maize seedlings were exposed to drought (DT) by suspending water supply. DEGs were screened after 3 days of DT-treated samples using the ACP-based technique. Several DEGs encoding 16.9 protein, antimicrobial protein, hypothetical protein NCLIV_068840, thioredoxin M-type were identified in maize leaves under drought stress. These genes have putative functions in plant defense response, growth and development. These identified genes would be useful for predictive markers of plant defense, and growth responses under drought stress in plants.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.225-231
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• 1999

Let Mf(x) be the Hardy-Littlewood maximal function on $\mathbb{R}^n$. Let $\Phi$ and $\Psi$ be functions satisfying $\Phi$(t) = ${\int^t}_0$a(s)ds and $\Psi(t)$ = ${\int^t}_0$b(s)ds, where a(s) and b(s) are positive continuous such that ${\int^\infty}_0\frac{a(s)}{s}ds$ = $\infty$ and b(s) is quasi-increasing. We show that if there exists a constant $c_1$ so that ${\int^s}_0\frac{a(t)}{t}dt\;c_1b(c_1s)$ for all $s\geq0$, then there exists a constant $c_1$ such that(0.1) $\int_{\mathbb{R^{n}}$ $\Phi(Mf(x))dx\;\leq\;c_2$ $\int_\mathbb{R^{n}}$$\Psi(c_2\midf(x)\mid)dx$ for all $f\epsilonL^1(R^n_$. Conversely, if there exists a constant $c_2$ satisfying the condition (0.1), then there exists a constant $c_1$ so that ${\int^s}_\delta\frac{a(t)}{t}dt=;\leq\;c_1b(c_1s$ for all $\delta$ > 0 and $s\geq\delta$.

• Journal of the Korean Mathematical Society
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• v.34 no.4
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• pp.1029-1036
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• 1997

Let ${A_t)}_{t>0}$ be a dilation group given by $A_t = exp(-P log t)$, where P is a real $n \times n$ matrix whose eigenvalues has strictly positive real part. Let $\nu$ be the trace of P and $P^*$ denote the adjoint of pp. Suppose that $K$ is a function defined on $R^n$ such that $$\mid$K(x)$\mid$ \leq k($\mid$x$\mid$_Q)$ for a bounded and decreasing function $k(t) on R_+$ satisfying $k \diamond $\mid$\cdot$\mid$_Q \in \cup_{\varepsilon >0}L^1((1 + $\mid$x$\mid$)^\varepsilon dx)$ where $Q = \int_{0}^{\infty} exp(-tP^*) exp(-tP)$ dt and the norm $$\mid$\cdot$\mid$_Q$ stands for $$\mid$x$\mid$_Q = \sqrt{}, x \in R^n$. For $f \in L^1(R^n)$, define $mf(x) = sup_{t>0}$\mid$K_t * f(x)$\mid$$ where $K_t(X) = t^{-\nu}K(A_{1/t}^* x)$. Then we show that $m$ is a bounded operator of $L^1(R^n) into L^{1, \infty}(R^n)$.

• Applied Biological Chemistry
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• v.23 no.1
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• pp.1-6
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• 1980

The sorption characteristics of red pepper powder were analyzed in respect to its storing humidities and the types of powder product. The sorption rate of the powder was affected by the humidity values under which it was stored. At low relative humidity values below 70% RH the sorption equilibrium was easily attained, but at the higher humidity over 75% RH the equilibrium state was not reached even after a long period of storage. From the estimation of the sorption rate at arbitrary humidity an empirical equation was obtained; In ${\frac{dw}{dt}}=n\;ln(t)+ln\;c$, where w is moisture content(%) absorbed, t is time (hour) and n and c are empirical constants which were determined from empirical data. Particle sizes and drying methods of red pepper showed little effect on the sorption behavior.

• Journal of the Korea Concrete Institute
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• v.28 no.2
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• pp.235-244
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• 2016

This study was conducted to verify seismic performance of special moment frame's joints at roof-level with high-strength concrete and SD600 bars. K-RC-H was designed according to the seismic code and K-HPFRC-H had 150% of the original hoop spacing and 1.0% steel fiber volume fraction compared with K-RC-H. Both specimens had remarkable seismic performance without noticeable decrease in moment, but with very good energy dissipation before rebar failure. The U-bars in the joint sufficiently constrained rebar's action that pushed the cover upward. SD600 bars with $1.25l_{dt}$ had minimum slip in the joint. It was considered that the steel fiber contributed to improvement of the bending moment and joint shear distortion, and the result showed that it would be possible to increase the hoop spacing to 150% of the regular spacing.

• Journal of Sensor Science and Technology
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• v.3 no.3
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• pp.9-15
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• 1994

Catalytic combustible gas sensors were fabricated by using ${\gamma}-Al_{2}O_{3}$ with large surface area and noble metal catalysts. The optimum conditions for ${\gamma}-Al_{2}O_{3}$ fabrication were investigated by DT/TGA and XRD analyses and it was found that fabricated ${\gamma}-Al_{2}O_{3}$ had superior value as surface area of $215.5m^{2}/g$. Gas sensors were manufactured and tested to inflammable gases by using Pt coil as a heater and temperature sensing part, fine ${\gamma}-Al_{2}O_{3}$ powder as a bead material and Pt, Pd noble metal powder as a catalyst. From the results, fabricated sensor showed good sensitivity to LPG and LNG of 20mV/l000ppm, 6.5mV/l000ppm respectively.