• Journal of Chest Surgery
• /
• v.33 no.8
• /
• pp.613-622
• /
• 2000

Background: The aim of this study is to define the cardioprotective effects(functional and metabolic) of newly developed DelNido cardioplegic solution(containing plasma solution, mannitol, magnesium and lidocaine). Material and Method: This study assessed the function of rat hearts after itermittent infusion of DelNido cardioplegia with different preserving methods(Air or Icebox) for 2hours and perfusing the hearts on a Langendorff apparatus. Heart rate, left ventricular developed pressure(LVDP) and coronary flow, were measured at pre-ischemic, post-reperfusion 15min, 30min and 45min. Coronary flow was standardized to dry heart weight. Each weight was weighted to calculate water content. Creatine kinase-MB isoenzyme release was measured and ultrastructural assessment was done with electron microscopes. Result: DelNido group was better than St, Thomas group and Icebox group was better than Room-air group. Conclusion: DelNido cardioplegia have better myocardial protective effects than St. Thomas cardioplegia when they were preserved in the Room-air. But we can not tell the difference between Delnido cardiplegia with Air preserving method and St. Thomas cardioplegia with Icebox.

• Textile Coloration and Finishing
• /
• v.32 no.2
• /
• pp.73-79
• /
• 2020

Pursuing the fabric materials for military chemical warfare protective clothing with the improved detoxification properties, this study investigated the simple and effective cotton treatment method using pad-dry-cure process and 3-aminopropyltrimethox ysilane(APTMS) solution for surface amination. Detoxification properties of the untreated and treated cotton fabrics were evaluated via decontamination of chemical warfare agent simulant, DFP(diisopropylfluorophosphate). The surface aminated cotton fabric increased the rate of the hydrolysis of DFP by the factor of 3 and the decontamination ratio reached 88.2% after 24h. Therefore, the surface amination of the cotton fabric with APTMS can be an effective pathway to prepare the material for protective clothing against chemical warfare agents.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.81-86
• /
• 2000

In recent modern protective systems have been introduced to reduce the vulnerability of bridges to seismic events. These protective systems include base isolation devices of different types, damping devices and active control devices. The objective of this study is to analytically evaluate the efficiency of a seismic retrofit scheme using base isolation systems, such as lead rubber bearings and sliding isolators. In this study, a triaxial model was used, which is capable of accurately developing the behavior of sliding isolators including the influence of the changing vertical force and velocity on the friction coefficients. Seismic response analyses of the bridge before and after retrofit were carried out by using a three-dimensional nonlinear seismic analysis program, IDARC-BRIDGE. To evaluate the efficiency of a retrofit scheme using triaxial isolators, a comparative study of performances of above two base isolation systems was conducted, and the numerical results show that the triaxial isolation solution can effectively reduce the sheat forces at the piers for the vertical ground motion.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.215-216
• /
• 2015

The application of fault current limiter(FCL) reduces power system fault current for circuit breaker to operate properly due to reduced fault current. Also FCL reduces through fault current to the power system equipments. But FCL has changed power system parameters for short time, before application the magnitude of register, triggering current and protective relay coordination have to be studied. In this paper we will examine protective relay coordination with FCL. And propose better solution to assist improving of power system operation through the application of FCL.

• The Research Journal of the Costume Culture
• /
• v.22 no.3
• /
• pp.361-370
• /
• 2014

The fabric, 100% Silk, was dyed with Atractylodes japonica extract solution. The effects of concentration of extracts (colorant), temperature of dyeing, time of dyeing and pH of dye bath were studied. As the concentration of extracts increased, color strength (K/S value) increased progressively. The K/S values increased with raising temperature, time and proper conditions were $80^{\circ}C$ and 80 minutes. Maximum K/S value was obtained at pH 3. The K/S values of mordanted fabrics were increased with increasing mordant concentration up to specific values. Surface color of dyed and mordanted fabrics were yellowish. Light color fastness of fabric with mordanting was fairly good 3/4 rating. The mordanted silk fabrics showed excellent antibacterial activity. The silk fabric dyed with Atractylodes japonica extract showed a superior UV protective property.

• Journal of the Ergonomics Society of Korea
• /
• v.9 no.1
• /
• pp.29-33
• /
• 1990

The need for the protection of workers in many industrial workstations has long been recognized, and many type of protective equipment have been devised. In many protective equipment designs, this study set limits to the safety helmet. The direct closed head impact problem was idealized as a linear-damped spring model. This study concerns what properties of helment should afford optimal protection in a direct closed head impact problem. The solution to the problem was achieved through analytic method and numerical computation. The answer was found in terms of 4 parameters : 1) rigidity of shell, 2) viscosity of shell, 3)rigidity of harness, 4) viscosity of harness. The choices are as follows 1) to reduce the rigidity value of harness as small as possible 2) to increase the viscosity value of harness as large as possible. 3) to select the rigidity value of shell sufficient for preventing a breakage.

• Corrosion Science and Technology
• /
• v.17 no.2
• /
• pp.45-53
• /
• 2018

A new 80Ti-15Ta-5Zr wt% alloy surface was protected by anodic oxidation in phosphoric acid solution. The protective oxide layer (TiO2, ZrO2 and Ta suboxides and thickness of 15.5 nm) incorporated $PO{_4}^{3-}$ ions from the solution, according to high resolution XPS spectra. The AFM analysis determined a high roughness with SEM detected pores (20 - 50 nm). The electrochemical studies of bare and anodically oxidized Ti-15Ta-5Zr alloy in Carter-Brugirard saliva of different pH values and saliva with 0.05M NaF, pointed to a nobler surface for the protected alloy, with a thicker electrodeposited oxide layer acting as a barrier against aggressive ions. The oxidized alloy significantly decreased corrosion current densities and total quantity of ions released into the oral environment in comparison with the bare one, at higher polarisation resistance and protective capacity of the electrodeposited layer. The impedance data revealed a bi-layered oxidation film formed by: a dense, compact, barrier layer in contact with the metallic substrate, decreasing the potential gradient across the metal/oxide layer/solution interface, reducing the anodic dissolution and a more permissive, porous layer in contact with the electrolyte. The open circuit potential for protected alloy shifted to nobler values, with thickening of the oxidation film signifying long-term protection.

• Journal of Chest Surgery
• /
• v.30 no.9
• /
• pp.847-853
• /
• 1997

Although the effects of adenosine on the heart, including the clinical suppression of cardiac arrhythmias, have been recognized for more than half a century, it is only in the last decade that the therapeutic potential of adenosine has been recognized. The objective of this study was to determine if augmentation of myocardial adenosine levels during global ischemia improves functional recovery after reperfusion. We used to modified Langendonf system to evaluate myocardial protective effect. Isolated rat hearts were subjected to 90 minutes of deep hypothermic arrest(15$^{\circ}C$) with modified St. Thomas'Hospital cardioplegic solution used to provide myocardial protection. Myocardial adenosine levels were augmented during ischemia by providing exogenous adenosine in the cardioplegic solution. Two groups of hearts w re studied: (1) control group(n=10) cardioplegia alone; (2) adenosine group(n=10) adenosine(0.75mg/kg/min) added to the cardioplegic solution. Significantly better percent recovery(p<0.01) in hemodynamics(except heart rate) at 60 minutes after reperfusion was evident compared to baseline values in the adenosine group. (systolic no란ic pressure : 78.5$\pm$3.6% vs 66.6$\pm$5.9%, airtic overflow volume : 61.7$\pm$ 11.6% vs 37.2$\pm$ 15.4%, coronary flow volume 77.1$\pm$7.5% vs 57.2$\pm$ 11.1%, and cardiac output : 65.6$\pm$ 11.5% vs 44.2$\pm$ 12.4%). Heart rate was similar in two groups(94.4$\pm$4.8% vs 95.3 $\pm$ 6.8%). Adenosine groups resulted in significantly rapid recovery time of heart beat after reperEusion(p<0.01) (24.5$\pm$7.6 sec. vs 179.0$\pm$ 131.1sec.). In biochemical study, CPK levels(0.1 $\pm$0.3U/L vs 1.4$\pm$0.8U/L) and lactic acid levels(0.08$\pm$0.Immol/L vs 0.34$\pm$0.2 mmol/L) were significantly low in adenosine groups(p<0.01). We concluded that adenosine included cardioplegia have better recovery effects after r perfusion in myocardial ischemia compared to adenosine free cardioplegia.

• Korean Journal of Veterinary Research
• /
• v.53 no.3
• /
• pp.169-174
• /
• 2013

We demonstrated that a mineral aqueous solution (MAS) administered to mice functionally and histologically protected against cisplatin-induced acute renal failure (ARF) and $CCl_4$-induced acute liver failure (ALF). In ARF model, 0.4 and 0.2% MAS decreased mortality and the serum concentrations of blood urea nitrogen (BUN) and creatine in mice. Additionally, 0.4 and 0.2% MAS reduced contraction of distal convoluted tubules and suppressed expression of the proinflammatory cytokines interlukein-6 (IL-6) and tumor necrosis factor (TNF-${\alpha}$) in the kidney. In ALF model, 0.4 and 0.2% MAS decreased serum concentrations of alanine aminotransferase and aspartate aminotransferase in mice. Additionally, 0.4 and 0.2% MAS reduced necrotic areas and suppressed expression of IL-6 and TNF-${\alpha}$ in the liver. These results indicate that a MAS might have protective effects against ARF and ALF.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.9-20
• /
• 1996

Oxygen free radicals can generated during metabolic processes in normal cells and by exposure of cells to toxic substances. These radicals have been recogenized to playa critical role in several pathological conditions including carcinogenesis and aging, and they have been implicated in pathogenesis of various diseases such as seizure, Alzheimer's disease, Parkinson's disease, myocardial infarction, respiratory distress syndrome, and rheumatoid arthritis. This study was undertaken to determine if Juglandis semen herb-acupuncture solution (JSHAS) has a protective effect against cell injury caused by oxidants, t-butylhydroperoxide (t-BHP) and $H_{2}O_2$. Cell injury was estimated by measuring lactate dehydrogenase (LDH) release and lipid perexidation was estimated by measurimg malondialdehyde, a product of lipid peroxidation. JSHAS significantly prevented LDH release induced by t-BHP or $H_{2}O_2$ in a dose-dependent manner at concentrations of 0.5-10%. Such protective effect was observed in control tissues untreated with oxidants. JSHAS, at 5% concentration, significantly reduced LDH release even when the concentrations of t-BHP and $H_{2}O_2$ increased to 5 and 200 mM, respectively. JSHAS, at 5% concentration, significantly reduced the lipid peroxidation by t-BHP and $H_{2}O_2$. These results indicate that JSHAS prevents cell injury and lipid peroxidation induced by oxidants in rabbit kidney cells. However, the underlying mechanisms remain to determined.