• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.67-70
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• 2013

Purpose: Surge in patients with hepatocellular carcinoma, hepatic artery chemical embolization is one of the effective interventional procedures. The PET/CT examination plays an important role in determining the presence of residual cancer cells and metastasis, and prognosis after embolization. The other hand, the hepatic artery chemical embolization of embolic material used lipiodol produced artifacts in the PET/CT examination, and these artifacts results in quantitative evaluation influence. This study, the radioactivity density and the percentage error was evaluated by the extent of the impact of lipiodol in the image of PET/CT. Materials and Methods: 1994 NEMA Phantom was acquired for 2 minutes and 30 seconds per bed after the Teflon, water and lipiodol filled, and these three inserts into the enough to mix the rest behind radioactive injection with $20{\pm}10MBq$. Phantom reconfigure with the iterative reconstruction method the number of iterations for two times by law, a subset of 20 errors. We set up region of interest at each area of the Teflon, water, lipiodol, insert artifact occurs between regions, and background and it was calculated and compared by the radioactivity density(kBq/ml) and the% Difference. Results: Radioactivity density of the each region of interest area with the teflon, water, lipiodol, insert artifact occurs between regions, background activity was $0.09{\pm}0.04$, $0.40{\pm}0.17$, $1.55{\pm}0.75$, $2.5{\pm}1.09$, $2.65{\pm}1.16 kBq/ml$ (P <0.05) and it was statistically significant results. Percentage error of lipiodol in each area was 118%, compared to the water compared with the background activity 52%, compared with a teflon was 180% of the difference. Conclusion: We found that the error due to under the influence of the attenuation correction when PET/CT scans after lipiodol injection performed, and the radioactivity density is higher than compared to other implants, lower than background. Applying the nonattenuation correction images, and after hepatic artery chemical embolization who underwent PET/CT imaging so that the test should be take the consideration to the extent of the impact of lipiodol be.

• The Korean Journal of Nuclear Medicine
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• v.35 no.2
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• pp.100-112
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• 2001

Purpose: The purpose of this study was to establish optimal imaging acquisition conditions for the GE $Advance^{TM}$ PET imaging system by performing the acceptance tests designed by National Electrical Manufacturers Association (NEMA) protocol and General Electric Medical Systems (GEMS) test procedures. Materials and Methods: Performance tests were carried out with $^{18}FDG$ radioactivity source and phantoms by using a standard acquisition mode. Transaxial resolution and scatter traction tests were performed with a line source and axial resolution with a point source, respectively. A cylindrical phantom made of polymethylmethacrylate (PMMA) was used to measure sensitivity, count rate losses and randoms, uniformity correction, and attenuation inserts were added to measure remaining tests. The test results were acquired in a diagnostic acquisition mode and analyzed mainly on high sensitivity mode. Results: Transaxial resolution and axial resolution were measured as average of 4.65 mm and 3.98 mm at 0 cm, and 6.02 mm and 6.71 mm at 20 cm on high sensitivity mode, respectively. Average scatter fraction was 9.87%, and sensitivity was $225.8kcps/{\mu}Ci/cc$ of trues. Activity at 50% deadtime was $4.6{\mu}Ci/cc$, and the error of count rate correction at that activity was from 1.49% to 3.83%. Average nonuniformity for total slice w3s 8.37%. The accuracy of scatter correction was -0.95%. The accuracies of attenuation correction were 5.68% for air, 0.04% for water and -6.51% for polytetrafluoroethylene (PTFE). Conclusion: The results satisfied most acceptance criteria, indicating that the GE $Advance^{TM}$ PET system can be optimally used for clinical applications.

• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.246-251
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• 2005

Purpose: There has been many reports for the effect of attenuation correction on myocardial perfusion SPECT. We studied the effect of attenuation correction with CT (computed tomography) in patients with normal coronary angiography. Materials and Methods: Fifteen patients with normal coronary artery on angiography and low likelihood of coronary artery disease were enrolled in this study (male: 6, female: 9, mean age: $58{\pm}8$ year). Myocardial perfusion SPECT was done with Millennium VG with Hawkeye device (GE, SPECT/CT camera). A visual analysis and polar map quantification (Emory tool box) was performed. In quantitative analysis, percent uptake of each myocardial wall on polar map (percent of maximal uptake) was compared between non-corrected (NC) and corrected (AC) images. Results: Visual analysis showed AC images led to an increase of uptake in the inferior wall, but decrease of uptake in the anterior wall, apex and septum. liver activity is also increased in AC images. In quantitative analysis, the percent uptake is decreased in the anterior wall, apex and septum, but increased in the inferior wall. It is helpful to interpret the images in the inferior wall after AC, but difficult in the apex and anterior wall after AC. Conclusion: AC is helpful in the inferior wall. But in the apex or anterior wall, AC must be carefully applied to normal perfused myocardium.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.732-737
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• 2008

This study developed a natural ingredient as a functional food possessing properties of attenuation of hypertension and cardiovascular hypertrophy. In a previous study hydrolysates obtained from chicken leg bone protein using Alcalase strongly inhibited angiotensin I converting enzyme (ACE) in vitro. In particular, hydrolysate (A4H) from four hours of incubation exhibited the highest ACE inhibitory activity (IC50 = 0.545 mg/ml). A4H was selected as a potent ACE inhibitor and orally administrated to spontaneously hypertensive rats (SHR) for eight weeks to investigate attenuating effects on age-related development of hypertension and cardiovascular hypertrophy. Results showed that treatment with A4H of SHRs attenuated the development of hypertension as effectively as the clinical antihypertensive drug captopril. Moreover, a significantly lower heart to body weight ratio and thinness of coronary arterial wall was observed in SHRs that had been treated with A4H or captopril. The results suggest that A4H can be utilized in developing an ACE inhibitor as a potential ingredient of functional foods to alleviate hypertension and cardiovascular hypertrophy.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.310-317
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• 2008

Lg amplitude decrease $Q^{-1}$ is very important because the Lg phase is the largest seismic phase in Korea if hazardous earthquakes occurred at neighbor nations such as Japan and China. Since reliable $Q^{-1}$ from two station method can be obtained by long pair distance of stations or events, we used seismic stations both Korea and Japans recording Korean events. The obtained $Q^{-1}$ values, however, were anomalously high; these misguided values, inconsistent with tectonic activity of Korean Peninsula, seems to be related with high $Q^{-1}$ values of Japan region.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.4
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• pp.323-331
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• 2001

A splanchic artery occlusion for 90 min followed by reperfusion of the mesenteric circulation resulted in a severe form of circulatory shock characterized by endothelial dysfunction, severe hypotension, marked intestinal tissue injury, and a high mortality rate. The effect of rutin, a flavonoid having antiprostanoid, anti-inflammatory, antithrombotic, antioxidant effect, were investigated in a model of splanchnic artery occlusion (SAO) shock in urethane anesthetized rats. Occlusion of the superior mesenteric artery for 90 min produced a severe shock state resulted in a fatal outcome within 120 min of reperfusion in many rats. Rutin was given as a bolus (1.28 mg/kg) 10 min prior to reperfusion. Administration of rutin significantly improved mean arterial blood pressure in comparison to vehicle treated rats (p＜0.05). Rutin treatment also resulted in a significant attenuation in the increase in plasma amino nitrogen concentration, intestinal myeloperoxidase activity, intestinal lipid peroxidation, infiltration of neutrophils in intestine and thrombin induced adherence of neutrophils to superior mesentric artery segments. These results suggest that rutin provides beneficial effects in part by preserving endothelial function and attenuating neutrophil accumulation in the ischemic reperfused splanchnic circulation.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.6
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• pp.579-586
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• 1999

Complement-mediated neutrophil activation has been hypothesized to be an important mechanism of reperfusion injury. It has been proposed that C1 esterase inhibitor (C1 INH) may prevent the complement- dependent activation of polymorphonuclear leukocytes (PMNs) that occurs within postischemic myocardium. Therefore, The effect of C1 INH was examined in neutrophil dependent isolated perfused rat heart model of ischemia (I) (20 min) and reperfusion (R) (45 min). Administration of C1 INH (5 mg/Kg) to I/R hearts in the presence of PMNs $(100{\times}10^6)$ and homologous plasma improved coronary flow and preserved cardiac contractile function (p＜0.001) in comparison to those I/R hearts receiving only vehicle. In addition, C1 INH significantly (p＜0.001) reduced PMN accumulation in the ischemic myocardium as evidenced by an attenuation in myeloperoxidase activity. These findings demonstrate the C1 INH is a potent and effective cardioprotective agent inhibits leukocyte-endothelial interaction and preserves cardiac contractile function and coronary perfusion following myocardial ischemia and reperfusion.

• Earthquakes and Structures
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• v.19 no.2
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• pp.145-156
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• 2020

The 24 January 2020 (Mw=6.8) earthquake with epicentre in Elazığ (Sivrice) on the East Anatolian Fault Zone caused loss of life and property. The information was given about the seismotectonic setting and regional seismicity along this fault zone and aftershock activity and ground motion data of this earthquake. Earthquake parameters were obtained for five different earthquake stations which were closer to the epicentre. Horizontal and vertical design spectra were obtained for the geographic locations for each earthquake station. The obtained spectra for the earthquake epicentre were compared with selected appropriate attenuation relationships. The damages after earthquake were evaluated via geotechnical and structural aspects. This study also aims to investigate the cause-effect relationships between structural damage in reinforced-concrete and masonry structures, respectively. The lack of engineering services was effective on the amount of damage in masonry structures. Insufficient reinforcement and concrete strength, dimensions and inadequate detailing increased the amount of damage in reinforced-concrete structures. Importance should be given to negative parameters that may weaken the defence mechanisms of structures for earthquake-resistant structural design.

• Nutrition Research and Practice
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• v.4 no.5
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• pp.438-442
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• 2010

Rhemannie Radix Preparata (RRP) has been previously employed in traditional oriental medicine as a treatment for diabetic thirst and improving blood flow. The aim of this study was to evaluate its hypoglycemic control by assaying the activities of key enzymes of carbohydrate metabolism in streptozotocin-(STZ)-induced diabetic rats. Further, RRP extracts were prepared in water (RRPW), in 50% ethanol (RRP50), and in 100% ethanol (RRP100), respectively, and compared for their actions in diabetic rats. The oral treatment of RRP (5 mg/kg b.w./d) to diabetic rats for 21 days resulted in a significant decline in blood glucose by 67% compared to diabetic control rats (P < 0.05). The altered activities of glucokinase, glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), and acetyl CoA carboxylase (ACC) in the livers of diabetic rats were reversed significantly to near-normal levels by the administration of RRP (P < 0.05). Among the three RRP extracts, RRP100 was the most effective in terms of hypoglycemic action. However, the administration of RRP to diabetic rats did not improve insulin production. The modulatory effects of RRP100 on the attenuation of carbohydrate enzyme activities appear to hold promise for widespread use for the treatment of diabetes in the future.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.471-477
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• 1998

Cyclosporin A (CsA), a widely used immunosuppressant, is well known to cause nephrotoxicity and hypertension as major side effects. The present study was aimed at investigating the effects of CsA-pretreatment on the activities of cytosolic guanylate cyclase (cGC) in relation to the alteration of relaxant responses in the rat thoracic aorta. CsA $(10\;{\mu}M)-preincubation$ for 90 min significantly attenuated the vasodilatation induced by sodium nitroprusside (SNP), a cytosolic guanylate cyclase activator, shifting the dose-response curve to the right. The increase in cGMP contents induced by SNP was markedly attenuated by CsA. SNP ($1\;{\mu}M{\sim}\;mM$) increased the cGC activity dose-dependently, and the increase was completely abolished by CsA. CsA attenuated the SNP-induced cGC activation dose-dependently. The abolishing effect of CsA-pretreatment on the SNP-induced cGC activation was not affected by washing the preparation, suggesting that the inhibition is irreversible. When CsA was added simultaneously with SNP, cGC activation was not attenuated. 1-(5-isoquinolinylsulfonyl)-2-methyl piperazine (H-7), a protein kinase C (PKC) inhibitor, decreased SNP-induced cGC activation and blocked the CsA-attenuation of cGC activation. These results suggest that CsA directly inhibits cGC participating in the CsA-induced impairment of vasodilatation, and that PKC is involved in the inhibitory action of CsA on cGC.