• Journal of Gastric Cancer
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• v.1 no.3
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• pp.174-179
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• 2001

Purpose: For curative resection of recurrent gastric cancer, it is imperative that there be no unrecognized foci of tumoral disease outside the operation field. PET (positron emission tomography) with FDG (18 fluoro-2 deoxy-D-glucose) is a whole-body imaging technique that exploits the increased rate of glycolysis in tumor cells to detect disease. The authors evaluated the usefulness of FDG-PET in assessing resectability of recurrent gastric cancer. Materials and Methods: Seven patients with recurrent gastric cancer were studied with FDG-PET from December 1998 to October 2000. All FDG-PET images were interpreted in conjunction with conventional diagnostic methods. All imaging results were correlated with the pathological diagnosis and clinical outcome. Results: A final diagnosis of recurrence was obtained at 14 sites in all 7 patients by histology or clinical follow up. Locoregional recurrence, including distant metastasis, developed in 6 of 7 patients and distant recurrence in only one. FDG-PET detected all recurrent sites (5 locoregional and 5 distant) in 5 patients without peritoneal recurrence, but did not detect peritoneal seeding in 2 patients with peritoneal recurrence. The accuracy of FDG-PET in estimating resectability was $71.4\%$ (5/7), and that of CT and PET together was $85.7\%$ (6/7). A curative resection could be performed in three of the recurrent patients (2 locoregional and 1 distant recurrence). Conclusion: Our results suggest that FDG-PET may be useful for detecting locoregional and distant recurrence of gastric cancer and for selecting appropriate treatment. However, considering that FDG-PET was limited in detecting peritoneal seeding and determining the exact anatomical extension of tumor, it should be used in conjunction with other anatomical images.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.314-317
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• 2002

The purpose of this study was to evaluate the clinical application of Patlak tool on GE PET workstation for quantitative analysis of dynamic PET images in cardiac patients. Three patients including coronary artery disease (CAD), myocardial infarction (MI), and angina were studied. All subjects underwent dynamic cardiac PET scan using a GE Advance scanner. After 10 min transmission scan for attenuation correction using two rotating $\^$68/Ge rod sources, three patients with cardiac disease were performed dynamic cardiac PET scan after the administration of approximately 370 MBq of FDG. The dynamic scan consisted of 36 frames with variable frame length (12${\times}$10s, 6${\times}$20s, 6${\times}$60s, 12${\times}$300s) for a total time of 70 min. Blood samples were obtained to determine the plasma substrate concentration. Region of interest of circular and rectangular shape to acquire input functions and tissue data were placed on left ventricle and myocardium. A value of 0.67 was used for lumped constant. Mean plasma substrate concentrations for three patients were 100 mg/dl (CAD), 100 mg/dl (MI), 132 mg/dl (angina), respectively. Regional MMRGlc values (mean${\pm}$SD) at lateral myocardium area for CAD, MI, and angina were 8.43${\pm}$0.24, 4.08${\pm}$0.16, and 6.15${\pm}$0.23 mg/min/100ml, respectively. Patlak tool on GE PET workstation appeared to be useful for quantitative analysis of dynamic PET images in cardiac patients, although further studies may be required for absolute quantitation.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.91-99
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• 2009

Noninvasive imaging of molecular and biological processes in living subjects with positron emission tomography(PET) provides exciting opportunities to monitor metabolism and detect diseases in humans. Measuring these processes with PET requires the preparation of specific molecular imaging probes labeled with $^{18}F$-fluorine. In this review we describe recent methods and novel trends for the introduction of $^{18}F$-fluorine into molecules which in turn are intended to serve as imaging agents for PET study. Nucleophilic $^{18}F$-fluorination of some halo- and mesyloxyalkanes to the corresponding $^{18}F$-fluoroalkanes with $^{18}F$-fluoride obtained from an $^{18}O(p,n)^{18}F$ reaction, using novel reaction media system such as an ionic liquidor tert-alcohol, has been studied as a new method for $^{18}F$-fluorine labeling. Ionic liquid method is rapid and particularly convenient because $^{18}F$-fluoride in $H_2O$ can be added directly to the reaction media, obviating the careful drying that is typically required for currently used radiofluorination methods. The nonpolar protic tert-alcohol enhances the nucleophilicity of the fluoride ion dramatically in the absence of any kind of catalyst, greatly increasing the rate of the nucleophilic fluorination and reducing formation of byproducts compared with conventional methods using dipolar aprotic solvents. The great efficacy of this method is a particular advantage in labeling radiopharmaceuticals with $^{18}F$-fluorine for PETimaging, and it is illustrated by the synthesis of $^{18}F$-fluoride radiolabeled molecular imaging probes, such as $^{18}F$-FDG, $^{18}F$-FLT, $^{18}F$-FP-CIT, and $^{18}F$-FMISO, in high yield and purity and in shorter times compared to conventional syntheses.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.233-237
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• 2009

It has widely been observed that the effect of elevating atmospheric $CO_2$ concentrations on rice productivity depends largely on soil N availabilities. However, the responses of ammonia volatilization from flooded paddy soil that is an important pathway of N loss and thus affecting fertilizer N availability to concomitant increases in atmospheric $CO_2$ and temperature has rarely been studied. In this paper, we first report the interactive effect of elevated $CO_2$ and temperature on ammonia volatilization from rice paddy soils applied with urea. Urea labeled with $^{15}N$ was used to quantitatively estimate the contribution of applied urea-N to total ammonia volatilization. This study was conducted using Temperature Gradient Chambers (TGCs) with two $CO_2$ levels [ambient $CO_2$ (AC), 383 ppmv and elevated $CO_2$ (EC), 645 ppmv] as whole-plot treatment (main treatment) and two temperature levels [ambient temperature (AT), $25.7^{\circ}C$ and elevated temperature (ET), $27.8^{\circ}C$] as split-plot treatments (sub-treatment) with triplicates. Elevated temperature increased ammonia volatilization probably due to a shift of chemical equilibrium toward $NH_3$ production via enhanced hydrolysis of urea to $NH_3$ of which rate is dependent on temperature. Meanwhile, elevated $CO_2$ decreased ammonia volatilization and that could be attributed to increased rhizosphere biomass that assimilates $NH_4^+$ otherwise being lost via volatilization. Such opposite effects of elevated temperature and $CO_2$ resulted in the accumulated amount of ammonia volatilization in the order of ACET>ACAT>ECET>ECAT. The pattern of ammonia volatilization from applied urea-$^{15}N$ as affected by treatments was very similar to that of total ammonia volatilization. Our results suggest that elevated $CO_2$ has the potential to decrease ammonia volatilization from paddy soils applied with urea, but the effect could partially be offset when air temperature rises concomitantly.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.73-79
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• 2006

Aeration is the most important and indispensable operation unit for the treatment of swine manure using aerobic liquid-composting process. The composting of swine manure depends on biological treatment process, but the highly concentrated ammonia nitrogen is required a pretreatment to expect the appropriate efficiency of the biological treatment process. In this study, pilot experiments have been carried out to estimate of the fit condition about ammonia stripping process as a pretreatment to aerobic liquid- composting. pH adjustment with $Ca(OH)_2$ was economically superior to use of NaOH and optimum pH of ammonia stripping was 12.3, ammonia nitorgen was rapidly removed as pH were increased at $$35^{\circ}C$$. When air stripping is performed before aerobic liquid-stripping, a high initial pH is required for complete ammonia removal and is additional effects such as organic substances, phosphorus, turbidity, and color removal. Stripping process was very efficient in the pretreatment of highly concentrated ammonia nitrogen for composting of swine manure. Emission rate of gaseous ammonia was $0.5355mole\;s^{-1}$ at initial time and $0.0253mole\;s^{-1}$ at finitial time. The fit condition of ammonia stripping in this study were at the temperature of $$35^{\circ}C$$, and the pH of 12.3 during 48 hours.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.2
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• pp.45-50
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• 2015

Compositionally graded AlGaN epilayer was grown by HVPE (hydride vapor phase epitaxy) on (0001) c-plane sapphire substrate. During the growth of graded AlGaN epilayer, the temperatures of source and the growth zone were set at $950^{\circ}C$ and $1145^{\circ}C$, respectively. The growth rate of graded AlGaN epilayer was about 100 nm/hour. The changing of Al contentes was investigated by field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS). From the result of atomic force microscope (AFM), the average of roughness in 2 inch substrate of graded AlGaN epilayer was a few nanometers scale. X-ray diffraction (XRD) with the result that the AlGaN (002) peak ($Al_{0.74}Ga_{0.26}N$) and AlN (002) peak were appeared. It seems that the graded AlGaN epilayer was successfully grown by the HVPE method. From these results, we expect to use of the graded AlGaN epilayer grown by HVPE for the application of electron and optical devices.

• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.117-129
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• 2002

Concentration of welding fumes and their components is known to be hazardous to welder and adjacent worker. To determine the generation rates of metals in fumes, $CO_2$ flux cored arc welding on stainless steel was performed in well designed fume collection chamber. Variables were different products of flux cored wire(2 domestic products and 4 foreign products) and input energy(low-, optimal- , high input energy). Mass of welding fumes was determined by gravimetric method(NIOSH 0500 method), and 17 metals were analysed by inductively coupled plasm-atomic emission spectroscopy(NIOSH 7300 method). Flux cored wire tube and flux were analysed by scanning electron microscopy to determine their metal composition. 17 metals were classified by their generation rates. Generation rates of iron, manganese, potassium and sodium were all above 50mg/min at optimal input energy level. Generation rates of chromium and amorphous silica were 25~50mg/min. At 1~25mg/min level, nickel, titanium, molybdenum, and aluminum were included. Copper, zinc, calcium, lead, magnesium, lithium, and cobalt were generated below 1 mg/min. Generation rates of metal components in fumes were influenced by input energy, types of flux cored wire. Flux cored wire was consisted of outer shell tube and inner flux. Iron, chromium, and nickel were the major components of outer tube. Flux contained iron, chromium, nickel, potassium, sodium, silica, and manganese. The use of flux cored wire can increase the hazards by increasing the amounts of fumes formed relative to that of solid wire. The reason might be the direct transfer of elements from the flux, since the flux is fine power. Ratio of metals to the fume of flux cored wire was lower than that of solid wire because non-metal components of flux were transferred. Total metal content of fumes in flux cored arc welding was 47.4(24.3~57.2) percent that is much lower than that of solid wire, 75.9 percent. We found that generation rates of iron, manganese, chromium and nickel, all well known to cause work related disease to welder, increased more rapidly with increasing input energy than those of fumes. To reduce worker exposure to fumes and hazardous component at source, further research is needed to develop new welding filler materials that decrease both the amount of fumes and hazardous components.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.285-294
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• 2011

The abatement of methane emission from ruminants is an important global issue due to its contribution to greenhouse gas with carbon dioxide. Methane is generated in the rumen by methanogens (archaea) that utilize metabolic hydrogen ($H_2$) to reduce carbon dioxide, and is a significant electron sink in the rumen ecosystem. Therefore, the competition for hydrogen used for methanogenesis with alternative reductions of rumen microbes should be an effective option to reduce rumen methanogenesis. Some methanogens parasitically survive on the surface of ciliate protozoa, so that defaunation or decrease in protozoa number might contribute to abate methanogenesis. The most important issue for mitigation of rumen methanogenesis with manipulators is to secure safety for animals and their products and the environment. In this respect, prophylactic effects of probiotics, prebiotics and miscellaneous compounds to mitigate rumen methanogenesis have been developed instead of antibiotics, ionophores such as monensin, and lasalocid in Japan. Nitrate suppresses rumen methanogenesis by its reducing reaction in the rumen. However, excess intake of nitrate causes intoxication due to nitrite accumulation, which induces methemoglobinemia. The nitrite accumulation is attributed to a relatively higher rate of nitrate reduction to nitrite than nitrite to ammonia via nitroxyl and hydroxylamine. The in vitro and in vivo trials have been conducted to clarify the prophylactic effects of L-cysteine, some strains of lactic acid bacteria and yeast and/or ${\beta}$1-4 galactooligosaccharide on nitrate-nitrite intoxication and methanogenesis. The administration of nitrate with ${\beta}$1-4 galacto-oligosaccharide, Candida kefyr, and Lactococcus lactis subsp. lactis were suggested to possibly control rumen methanogenesis and prevent nitrite formation in the rumen. For prebiotics, nisin which is a bacteriocin produced by Lactococcus lactis subsp. lactis has been demonstrated to abate rumen methanogenesis in the same manner as monensin. A protein resistant anti-microbe (PRA) has been isolated from Lactobacillus plantarum as a manipulator to mitigate rumen methanogenesis. Recently, hydrogen peroxide was identified as a part of the manipulating effect of PRA on rumen methanogenesis. The suppressing effects of secondary metabolites from plants such as saponin and tannin on rumen methanogenesis have been examined. Especially, yucca schidigera extract, sarsaponin (steroidal glycosides), can suppress rumen methanogenesis thereby improving protein utilization efficiency. The cashew nutshell liquid (CNSL), or cashew shell oil, which is a natural resin found in the honeycomb structure of the cashew nutshell has been found to mitigate rumen methanogenesis. In an attempt to seek manipulators in the section on methane belching from ruminants, the arrangement of an inventory of mitigation technologies available for the Clean Development Mechanism (CDM) and Joint Implementation (JI) in the Kyoto mechanism has been advancing to target ruminant livestock in Asian and Pacific regions.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.2959-2964
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• 2014

While several reproductive and lifestyle-related factors are already well-known as established risk factors for breast cancer, environmental factors have attracted attention only recently. The objective of the current study was to assess the association between the breast cancer incidences in females, the mortality rate and the number of motor vehicles on the one side and the consumption of gasoline which could work as a major source of air pollution at the other side. The breast cancer incidences and the mortality trends were compared with various indices of westernization like dietary patterns or industrialization with 10 years lag of time. Geographical variations with 10, 15 and 20 years lag of time were assessed between the breast cancer incidence in 2010 and the number of motor vehicles as well as the consumption of gasoline. The upward trend of motor vehicle numbers proved to be comparable to those of breast cancer incidence and mortality. However, the consumption of gasoline started to decrease since the mid-1990s. The geographic distribution of motor vehicle numbers and gasoline consumption in 1990 is in a positive correlation with the breast cancer incidence rates in 2010 and the 20-year lag time ($R^2$ 0.379 with the number of motor vehicles and 0.345 with consumption of gasoline). In a linear relationship between the breast cancer incidences in 2010 and the log transformed number of motor vehicles, the log transformed consumption of gasoline in 2000 also showed a positive relationship ($R^2$ 0.367 with the number of motor vehicles and 0.329 with consumption of gasoline). The results of the current study indicate that there may be a positive relation between the number of vehicles, gasoline consumption and the incidence of breast cancer from the aspects of long-term trends and geographical variation.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.73-79
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• 2004

The objective of the present study was to determine whether ${\beta}$1-4 galacto-oligosaccharides (GOS) and Candida kefyr combined with nitrate as manipulators could suppress rumen methanogenesis without nitrate poisoning in sheep. Four rumen fistulated wethers were allocated to a $4{\times}4$ Latin square design. Nitrate (1.3 g $NaNO_3$ $Kg^{-0.75}$body weight) with and without GOS and Candida kefyr were administered into the rumen through fistula as a single dose 30 min after the morning meal. GOS and Candida kefyr were supplemented by sprinkling onto the feed and through rumen fistula, respectively. The four treatments consisted of saline, nitrate, nitrate plus GOS and nitrate plus GOS plus Candida kefyr. Physiological saline was used as the control treatment. Compared to saline treatment, the administration of nitrate alone resulted in a very marked decrease in rumen methanogenesis and an increase in rumen and plasma nitrite production and blood methaemoglobin formation consequently causing a decline in oxygen consumption, carbon dioxide production and metabolic rate. When compared to nitrate alone, the simultaneous administration of nitrate with GOS decreased nitrite accumulation in rumen and plasma and nitrate-induced methaemoglobin, while retaining low methane production. However, GOS could not fully restore metabolic parameters reduced by nitrate. When compared to the simultaneous administration of nitrate with GOS, the simultaneous administration of nitrate with GOS plus Candida kefyr lowered rumen methanogenesis to a negligible level, but did not decrease rumen and plasma nitrite accumulation as well as blood methaemoglobin formation. Thus, these results suggest that combination of nitrate with GOS may be a potent manipulator to suppress rumen methanogenesis with abating the hazards of nitratenitrite toxicity in ruminants.