• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.5 no.1
• /
• pp.51-61
• /
• 2002

Purpose: The most common causes of neonatal cholestasis are neonatal hepatitis (NH) and extrahepatic biliary atresia (EHBA). Since neonatal cholestasis presents with variable expression of same pathologic process and has similar clinical, biochemical, and histologic features between EHBA and idiopathic neonatal hepatitis (NH), differential diagnosis is often difficult. We reviewed the differences of clinical characteristics and laboratory data to find out any correlation between the results of $Tc^{99m}$ DISIDA scan and presence of acholic stool. Methods: Between June 1993 and January 2001, total 29 infants younger than 4 month-old underwent $Tc^{99m}$ DISIDA scan. Their biochemical tests and clinical course were reviewed retrospectively. Results: Patients who had negative intestinal activity on $Tc^{99m}$ DISIDA scan showed acholic stool and revealed higher serum direct bilirubin and urine bilirubin level. 18.2% of patients with acholic stool showed intestinal activity on $Tc^{99m}$ DISIDA scan and 81.8% of them did not. All the patients without acholic stool showed positive intestinal activity on $Tc^{99m}$ DISIDA scan. The result of $Tc^{99m}$ DISIDA scan and the presence of acholic stool showed high negative correlation (r :-0.858). Patients with acholic stool and negative intestinal activity on $Tc^{99m}$ DISIDA scan showed higher serum total bilirubin level. Patients without acholic stool and positive intestinal activity on $Tc^{99m}$ DISIDA scan showed higher serum level of ALT. Conclusion: Patients with acholic stool and negative intestinal activity showed high correlation, but 18.2% of patients with acholic stool showed positive intestinal activity. So operative cholangiogram or transcutaneous liver biopsy should be performed for confirmation.

• Journal of Nutrition and Health
• /
• v.49 no.6
• /
• pp.411-419
• /
• 2016

Purpose: Dysregulation of adipokines caused by excess adipose tissue has been implicated in the development of obesity-related metabolic diseases. This study evaluated the effects of mugwort (Artemisia princeps Pampanini) ethanol extract on lipid metabolic changes, insulin resistance, adipokine balance, and body fat reduction in obese rats. Methods: Male Sprague-Dawley rats were fed either a control diet (NC), high-fat diet (HF, 40% kcal from fat), or high-fat diet with 1% mugwort extract (HFM) for 6 weeks. Results: Epididymal and retroperitoneal fat mass increased in the HF group compared with the NC group, and epididymal fat mass was reduced in the HFM group (p < 0.05). No difference was observed in serum levels of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) among the groups. However, triglyceride (TG), TG/HDL-C ratio, and TC/HDL-C ratio increased in the HF group and significantly decreased in the HFM group. TG and TC levels in the liver were significantly higher in the HF group, whereas these levels were significantly reduced in the HFM group. HF rats had lower insulin sensitivity as indicated by increased homeostasis model assessment of the insulin resistance (HOMA-IR) value. HOMA-IR values significantly decreased in the HFM group. Adiponectin levels were higher in NC rats, and their leptin and PAI-1 levels were lower. Relative balance of adipokines was reversed in the HF group, with lower adiponectin levels but higher leptin and PAI-1 levels. In contrast, the HFM group maintained balance of adiponectin/leptin and adiponectin/PAI-1 levels similar to NC by reducing leptin and PAI-1 levels. Conclusion: Overall data indicated that mugwort extract can be effective in alleviating metabolic dislipidemia, insulin resistance, and adipokine dysregulation induced by a high-fat diet.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.797-803
• /
• 2019

This study was carried out to reduce the lateral vibration of high-speed electric multiple units. In the study, the high-speed electric multiple unit prototype (HEMU-430X) has a high lateral vibration at low equivalent conicity regardless of the wheel profiles (XP55, GV40, S1002). As wheel wear progresses and the equivalent conicity increases, the lateral vibration tends to decrease. The reason is that a combination of the suspension characteristics causes the body and bogie to resonate at a frequency of 1.4 Hz when the equivalent conicity is low, resulting in body hunting. An investigation of the lateral vibration of overseas high-speed trains showed that a decrease in the hydraulic stiffness of the yaw damper could improve the vibration. The series stiffness of the yaw damper is a combination of the hydraulic stiffness and elastic joint. In this study, an attempt was made to improve the lateral vibration by lowering the stiffness of the elastic joint. The series stiffness of the adjusted yaw damper was approximately 60% compared to the original one. The on track test results showed improvement in the lateral vibration for both running directions. The vibration reduction method of this study can be used for EMU-250 and EMU-320 in future commercial operations.

• Progress in Medical Physics
• /
• v.21 no.1
• /
• pp.93-98
• /
• 2010

The aim of this work was to establish the methodology for event positioning by measuring depth of interaction (DOI) information and to evaluate the system sensitivity and spatial resolution of the new detector for I-125 and Tc-99m imaging. For this purpose, a Monte Carlo simulation tool, DETECT2000 and GATE were used to model the energy deposition and light distribution in the detector and to validate this approach. Our proposed detector module consists of a monolithic CsI(Tl) crystal with dimensions of $50.0{\times}50.0{\times}3.0\;mm^3$. The results of simulation demonstrated that the resolution is less than 1.5 mm for both I-125 and Tc-99m. The main advantage of the proposed detector module is that by using 3 mm thick CsI(Tl) with maximum-likelihood position-estimation (MLPE) method, high resolution I-125 imaging and high sensitivity Tc-99m imaging are possible. In this paper, we proved that our new detector to be a reliable design as a detector for a multi-energy SPECT.

• Journal of Magnetics
• /
• v.19 no.3
• /
• pp.248-254
• /
• 2014

The purpose of this study is to figure out how uptake counts of technetium ($^{99m}Tc$) among radioisotopes in the human body are affected if computed tomography (CT), magnetic resonance imaging (MRI) and isotope examination are performed consecutively. $^{99m}Tc$ isotope material, iodinated contrast media for CT and paramagnetic contrast media for magnetic resonance (MR) were used as experimental materials. First, $^{99m}Tc$ was added to 4 cc normal saline in a test tube. Then, 2 cc of CT contrast media such as $Iopamidol^{(R)}$ and $Dotarem^{(R)}$ were diluted with 2 cc normal saline, and 2cc of MRI contrast media such as $Primovist^{(R)}$ and $Gadovist^{(R)}$ were diluted with 2 cc normal saline. Each distributed contrast media was a total of 4 cc and included 10m Ci of $^{99m}Tc$. A gamma camera, a LEHR (Low energy high resolution) collimator and a pin-hole collimator were used for image acquisition. Image acquisition was repeated a total of 6 times and 120 frames were obtained and uptake counts of $^{99m}Tc$ were measured (from this procedure). In this study, as a result of measuring the uptake counts of $^{99m}Tc$ using the LEHR collimator, the uptake counts were less measured in all contrast media than normal saline as a reference. In particular, the lowest uptake counts were measured when $Gadovist^{(R)}$, contrast media for MRI, was used. However, the result of measuring the uptake counts of $^{99m}Tc$ using the pin-hole collimator showed higher uptake counts in all contrast media, except for $Iopamidol^{(R)}$, than normal saline as a reference. The highest uptake counts were measured particularly when $Primovist^{(R)}$, contrast media for MRI, was used. In performing the gamma camera examination using contrast media and $^{99m}Tc$, it is considered significant to check the changes in the uptake counts to improve various diagnosis values.

• Mycobiology
• /
• v.41 no.2
• /
• pp.94-99
• /
• 2013

In this study, ethanolic extracts from Hericium erinaceum cultivated with Artemisia capillaris (HEAC) were assessed for their ability to lower the cholesterol levels of male Sprague-Dawley rats fed a high-fat diet. Rats were randomly subdivided into seven test groups. Each group contained eight rats fed a high-fat diet during a growth period lasting 4 wk. Supplementation with the extracts was performed once a day for 2 wk after the high-fat diet. The control group (rats fed a high-fat diet) showed a high efficiency ratio (feed efficiency ratio) value compared to the normal group. Biochemical parameters, including total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), and triglyceride (TG) levels dramatically increased in the control group compared to the normal group. High-density lipoprotein-cholesterol (HDL-c) content in the control group was also significantly lower relative to the normal group. Two positive control groups, treated with simvastatin and atorvastatin, had lowered TC, LDL-c, and TG levels, and increased HDL-c content compared to the control group. Treatment with the tested extracts, including HEAC, ethanolic extracts from Hericium erinaceum, and ethanolic extracts from Artemisia capillaris reduced TC, LDL-c, and TG levels and elevated HDL-c content in the hyperlipidemia rats. The atherogenic index and cardiac risk factor values for the HEAC-treated group were 0.95 and 1.95, respectively. Simvastatin- and atorvastatin-treated groups showed atherogenic index values of 1.56 and 1.69, respectively, and cardiac risk factor values of 2.56 and 2.69, respectively. These results show HEAC possesses an ability to cure hyperlipidemia in rats and may serve as an effective natural medicine for treating hyperlipidemia in humans.

• Journal of Life Science
• /
• v.26 no.6
• /
• pp.657-662
• /
• 2016

Cladosiphon okamuranus is edible brown algae cultured commercially and extensively on the Okinawa coast in Japan. We examined the effects of Cladosiphon okamuranus on the lipid metabolism in high-fat-diet rats. Seven-week-old female SD rats were divided into five groups and fed high-fat diets for 42 days. In addition, Cladosiphon okamuranus was administered orally for 42 days at 95 mg/kg of the body weight of the rats. The effects of lipid metabolism were evaluated by the total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), glutamic pyruvate transaminase (GPT), glutamic oxalacetic transaminase (GOT) levels in sera. The levels of TC, TG, LDL, GPT, and GOT were reduced in the Cladosiphon okamuranus treated group compared with the high-fat diet group. However, the levels of HDL in the Cladosiphon okamuranus treated groups were higher than in the high-fat diet groups. These results demonstrated that Cladosiphon okamuranus had positive effects on lipid metabolism, suggesting Cladosiphon okamuranus could be used as an ingredient in useful, functional products.

• Journal of Biomedical Engineering Research
• /
• v.16 no.2
• /
• pp.231-238
• /
• 1995

Tc-99m-MIBI (Sestamibi) myocardial SPECT along with TI-201 tomographic Imaging has demonstrated wide application and high image quality sufficient for the diagnosis of myocardial perfusion defect, which consequently reflects regional myocardial blood flow. The qualitative values of myocardial SPECT with Tc-99m-MIBI as well ds the quantitative cases depend in some degree on the reconstruction techniques of multiple projections. Filtered backprojection (FBP) Is the common standard method for reconstruction rather than the complicated and time-consuming arithmetic methods. In FBP it is known that the distribution of radioactivity in reconstructed transverse slices varies with the selected litter parameters such as cutoff frequencies and order (Butterworth case) The cutoff frequencies used in clinicAl practice partially remove and decrease the true radioactive distribution and alter the pixel counts, which lead to underestimation of true counts in specific myocardial regions. In this study, we have investigated the effect of cutoff frequencies of reconstruction filter on the artifactually induced perfusion defects, which are often demonstrated near inferior and/or inferoseptal cardiac walls due to the intense hepatic uptake of Tc-99m-MIBI. A computerized method for Identifying the relative degree of artifactual perfusion defect and for comparing those degrees along with the relative amount of hepatic uptake to myocardium was developed and patient images were studied to observe the quantitative degree of underestimation of myocardial perfusion, and to propose some reasonable threshold of cutoff frequency in the diagnosis of perfusion defect quantitatively. We concluded that from the quantitative viewpoint cutoff frequencies may be used as high as possible with the sacrifice of homogeneity of image quality, and those frequencies lower than the common 0.3 Wyquist frequency would reveal severe degradation of radioactive distribution near inferior and/or inferoseptal myocardium when applying Butterworth or low pass filter.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.16 no.2
• /
• pp.195-202
• /
• 2018

As a rule, geological disposal is considered a safe method for final disposal of high-level radioactive waste. However, some long-lived fission products like $^{99}Tc$ and $^{129}I$ contained in spent nuclear fuel are highly mobile as less sorbing anionic species in the subsurface environment and can mainly cause exposure dose to the ecosystem by emission of beta rays in the hundreds of keV range. Therefore, if these two nuclides can be separated and converted with high efficiency into radioactively unharmful nuclides, this would have a positive effect on disposal safety. One candidate method is to transmute these two nuclides in nuclear reactors into short-lived nuclides or into stable nuclides. For this purpose, it is necessary to evaluate which reactor type is more efficient in burning these two nuclides. In this study, the simulation results of nuclear transmutation of $^{99}Tc$ and $^{129}I$ in light water reactor (PWR), heavy water reactor (CANDU) and fast neutron reactor (SFR, MET-1000) are compared and discussed.

• Journal of Korea Water Resources Association
• /
• v.52 no.1
• /
• pp.11-19
• /
• 2019

In this study, the actual evapotranspiration products of Global Land Data Assimilation System (GLDAS), Global Land Evaporation Amsterdam Model (GLEAM) and MOD16, which are satellite- and reanalysis-based dataset, were validated at the flux tower sites (i.e., CFK and SMK) managed by Korea Institute of Hydrological Survey, and the uncertainty and correlation analysis were conducted using Triple Collocation (TC) method. The result of validation with the flux tower showed better agreement in the order of GLEAM> GLDAS>MOD16. At the result of three combinations (S1: flux tower vs. GLDAS vs. MOD16, S2: flux tower vs. GLDAS vs. GLEAM, S3: flux tower vs. GLEAM vs. MOD16), the order of best to worst is GLEAM, GLDAS, MOD16, and flux tower for CFK (GLDAS> GLEAM>MOD16>flux tower for SMK). Since the error variance and correlation coefficients of the flux tower show relatively worse performance in TC analysis than the other products, By applying TC method to three products (GLDAS vs. GLEAM vs. MOD16), the uncertainty of each dataset were evaluated at the Korean Peninsula, As a results, the GLDAS and GLEAM performed reasonable performance (low error variance and high correlation coefficient), whereas results of MOD16 showed high error variance and low correlation coefficient at the cropland.