• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.285-291
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• 2006

The lysimeter ($1.2m\;with{\times}1.6m\;length$) experiment using $^{15}N$ tracer method was conducted to investigate the influence of slopes (degree 5, 15 and 30%) and fertilizer application methods (solid application and fertigation) on the behavior of applied urea in saprolite piled highland with Chinese cabbage cultivation. NDFFs(nitrogen derived from fertilizer) in soil were increased with decreasing of degree of slope and of depth of soil. The recovery as percentage of fertilizer nitrogen by Chinese cabbage were 69.5% for solid application and 76.5% for fertigation in 5% slope, 65.0% for solid application and 70.2% for fertigation in 15% slope, and 56.1% for solid application and 62.3% for fertigation in 30% slope. There, fertigation will make great contributions to the reduction of environmental contamination by run off and to the increase of fertilizer efficiency in Chinese cabbage cultivated highland.

• Nuclear Engineering and Technology
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• v.10 no.4
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• pp.215-222
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• 1978

Using tracer technique of $^{65}Zn$, a field experiment has been carried out to evaluate the efficiency of zinc fertilizer by rice plant grown under flooded conditions. The treatments include zinc slufate mixed throughout the soil with and without organic matter, combined urea-zinc fertilizer (N: 37.7%, Zn: 3.1%), and surface application at transplaning and two weeks after transplanting at the rate of 5kg Zn/ha respectively. Other treatments were zinc sulfate mixed throughout the soil at the rate of 10 kg and 20 kg Zn/ha respectively. Root dipping in 2 % ZnO suspension, only organic matter added, and control were also included. There was not much difference in rough grain yield between zinc levels and different application methods, but the highest yield was obtained from the treatment of the root dipping in 2% ZnO suspension. Among the 5kg Zn/ha treatments, the highest total zinc yield was observed from the zinc mixed throughout the soil. The organic matter treatment seemed to reduce the zinc fertilizer efficiency. In case of the zinc fertilizer levels, 5kg Zn/ha mixed throughout the soil showed the highest zinc fertilizer efficiency as compared with 10kg and 20kg Zn/ha treatments.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.39-44
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• 2013

This study evaluated the effect of fluid flow on the power density in a horizontal-flow microbial fuel cell (MFC). The maximum power densities in four types of flow induced by different channel types in the anode chamber were investigated. The fluid flow at each channel was analyzed using tracer tests. Results of polarization curves showed that the maximum power densities of case 1, 2, 3 and 4 were 95.7, 129.1, 190.9 and 114.2 mW/m2, respectively. Case 3 with a set of guide walls where flow had an S type-like shape showed the highest power density. Based on the Morrill Dispersion Index (MDI) value of case 4, microbial activity would be enhanced since the reactor allows even distribution of substrate but the overflow occurrence would not guarantee stable performance. Therefore, case 3 could be an effective reactor type for MFC because of high electricity generation and stable performance.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.71-80
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• 1982

In the present communication, the results will be reported on a clinical study of how well scintigraphic visualization of the hepatobiliary elements and several commonly used clinical liver function tests correlate each other in various diseases oft hepatobiliary system. The demonstrability of the biliary tract, gallbladder (GB) and duodenum was rather closely paralleled to serum bilirubin level and less closely to alkaline phosphatase and rather poorly to SGOT and SGPT. The biliary tree could not be visualized scintigraphically when bilirubin exceeded 10.5mg/dl. The usefulness of Tc-99m EHIDA [N-(2,6-diethylacetanilido) iminodiacetic acid, made by Amersham, England] hepatobiliary scintigraphy (Tc EHIDA HBS) in settling diagnostic controversy and ambiguity raised by oral cholecystography, intravenous cholangiography and ultrasonography in many hepatobiliary diseases is well known. The purpose of this investigation was to semiquantitatively evaluate the scintigraphic demonstrability of the hepatobiliary tract, GB and duodenum following intravenous injection of Tc-99m EHIDA in normal subjects and in patients with a disturbed liver function from various hepatobiliary diseases. The hepatobiliary scintigraphy was performed in 10 normal subjects and 39 patients with various hepatobiliary diseases (Table 1) at the Dept. of Radiology, St. Mary's Hospital Catholic Medical College, Seoul, Korea during 2 years period from September 1979. Scintigraphic examination was started at end of 3 minutes after intravenous injection of Tc-99m EHIDA in the amount of $50{\mu}Ci/kg$ and was continued until after 30 minutes at 5 minutes interval. The imaging was usually terminated when the tracer could be seen in the duodenum. Late scintigrams were obatained at 1 1/2, 3, 4 and 6 hours when reeded. Scintigrams were analyzed in terms of promptness and clarity of visualization of the biliary tree, GB and duodenum and demonstrability of these anatomical landmarks was correlated with the values of liver function tests. The demonstrability of the common hepatic duct, common bile duct, GB and duodenum was closely paralleled to the level of serum bilirubin when it is less than 10.5 mg/dl as shown in figure 1. However when the bilirubin exceeded 10.5 mg/dl the time of visualization between protracted reaching a flat curve or plateau around 10.5 mg/dl. The biliary tract could not be visualized when the bilirubin was higher than 10.5 mg/dl. The correlability between scintigraphic demonstration and serum alkaline phosphatase was less strong and between scintigraphic demonstration and SGOT and SGPT was rather poor. The present clinical study confirmed the usefulness and limitation of Tc-99m EHIDA hepatobiliary scintigraphy in visulizing and diagnosing the biliary system and duodenum when radiogrpahy and ultrasonography failed to provide useful informations. Scintigraphy was very helpful in the diagnosis of neonatal hepatitis, biliary atresia, cholecystitis and extrahepatic biliary obstruction. The hepatobiliary system and duodenum were visualized when serum bilirubin level was less than 10.5 mg/dl, SGOT 135 units, SGPT 114 units and alkaline phosphatase 52.2 KAU.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.57-71
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• 2004

Based on the data obtained under the China-Korea joint project (1997-2001) and historic observations, the distribution, transportation and sedimentation of sediment in the southern Yellow Sea (SYS) are discussed, and the controversial formation mechanism of muddy sediments is also explored. The sediment transport trend analysis indicates that the net transport direction of sediment in the central SYS (a fine-grained sediment deposited area) points to $123.4^{\circ}E,\;35.1^{\circ}N$, which is a possible sedimentation center in the central SYS. The sediment transport pattern is verified by the distribution of total suspended matter (TSM) concentration and ${\delta}^{13}C$ values of particulate organic carbon (POC), the latter indicates that the bottom water plays a more important role than the surface water in transporting the terrigenous material to the central deep-water area of the SYS, and the Yellow Sea circulation is an important control factor for the sediment transport pattern in the SYS. The carbon isotope signals of organic matter in sediments indicate that the Shandong subaqueous delta has high sedimentation rate and the deposited sediments originate mainly from the modern Yellow River. The terrigenous sediments in deep-water area of the SYS originate mainly from the old Yellow River and the modern Yellow River, and only a small portion originates from the modern Yangtze River. The analytical results of TSM and stable carbon isotopes are further confirmed by another independent tracer of sediment source, polycyclic aromatic hydrocarbons (PAHs). Five light mineral provinces in the SYS can be identified and they indicate inhomogeneity in sources and sedimentary environment. The modern shelf sedimentary processes in the SYS are controlled by shelf dynamic factors. The muddy depositional systems are produced in the shelf low-energy environments, which are controlled by some meso-scale cyclonic eddies (cold eddies) in the central SYS and the area southwest of the Cheju Island. On the contrary, an anticyclonic muddy depositional system (warm eddy sediment) appears in the southeast of the SYS (the area northwest of the Cheju Island). In this study, we give the cyclonic and anticyclonic eddy sedimentation patterns.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1049-1056
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• 2007

This study was conducted to compare the methane ($CH_4$) production estimated by in vivo (sulfur hexafluoride tracer technique ($SF_6$)) with that of two in vitro rumen simulation (RUSITEC) and gas production (IVGPT)) techniques. Four adult dry Holstein cows, aged $7.4{\pm}3.0$ years and weighing $697{\pm}70$ kg, were used for measuring methane production from five diets by the $SF_6$ technique. The experimental diets were alfalfa hay ($D_1$), corn silage + soybean meal (SBM) (910: 90, $D_2$), Italian rye grass hay +SBM (920: 80, $D_3$), rice straw +SBM (910: 90, $D_4$) and Sudan grass hay +SBM (920: 80, $D_5$). Each diet was individually fed to all 4 cows and 5 feeding studies of 17 d each were conducted to measure the methane production. In the RUSITEC, methane production was measured from triplicate vessels for each diet .In vitro gas production was measured for each of the diets in triplicate syringes. The gas produced after 24 and 48 h was recorded and gas samples were collected in vacuum vials and the methane production was calculated after correction for standard temperature and pressure (STP). Compared to the $SF_6$ technique, estimates of methane production using the RUSITEC were lower for all diets. Methane production estimated from 24 h in vitro gas production was higher (p<0.001) on $D_1$ as compared to that measured by $SF_6$, whereas on $D_2$ to $D_5$ it was lower. Compared to $SF_6$, methane production estimated from 48 h in vitro gas production was higher on all diets. However, methane estimated from the mean of the two measurement intervals (24+48 h/2) in IVGPT was very close to that of $SF_6$ (correlation 0.98), except on $D_1$. The results of our study confirmed that IVGPT is reflective of in vivo conditions, so that it could be used to generate a database on methane production potential of various ruminant diets and to examine strategies to modify methane emissions by ruminants.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.4
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• pp.23-36
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• 2000

Bottom sea waters in eight stations including from inner bay to outer bay to understand the importance of the submarine groundwater discharge for the environmental assessment of Chinhae Bay was collected in August 1999 and January 2000. Generally, /sup 222/Rn is very useful tracer to assess the submarine groundwater discharge because it is 2-4 orders of magnitude more concentrated in groundwater compared to surface water. The /sup 222/Rn activities ranged between about 33 to 182 dpm/100kg within the bay. Higher activities more than 100 dpm/100kg were found at the inner bay. The /sup 226/Ra activities, its parent, however, were little different between stations. /sup 222/Rn activities at the same station varied with season. It suggests that the major source of /sup 222/Rn is not from the bottom sediment, but from the change of submarine groundwater discharge by precipitation. The contents of Cl/sup -/ and SO/sub 4//sup 2-/ in the groundwater of Wonjeon-ri were very high as 1,312 and 369 ppm, respectively, indicating that this groundwater along the Chinhae coast was affected by seawater. Therefore, the submarine groundwater in the inner Bay may discharge to the overlying water. It indicates that these submarine groundwater discharges may play an important role as another important source of nutrients in the Chinhae Bay, because groundwater around the Chinhae Bay showed high concentration of dissolved inorganic nutrients (average , nitrate>174 μM, silicate>262 μM). Therefore, further studies are required to assess the contribution by the submarine groundwater discharge in the biogeochemical processes of the Chinhae Bay.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.342-348
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• 2001

Objective : Dopamine transporter concentrations have been known to decrease in Parkinson's disease(PD). The aim of the present study was to evaluate the correlation between SPECT measurements of [I-123]N-(3-iodopropene-2-yl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-chlorophenyl) tropane(IPT) as an imaging agent for measuring changes in transporter concentrations with PD. Patients and Methods : IPT labelled with $4.87{\pm}1.29mCi$($180.19{\pm}47.73MBq$) of [I-123] was intravenously injected into 23 patients(age : $58{\pm}12$) with PD and three normal controls(NC)(age : $37{\pm}7$) as bolus. Brain SPECT were then performed at 1 hour and 2 hours after injection on a double headed camera. The statistical parameters were the contrast ratio of left basal ganglia(BG) and right basal ganglia to occipital cortex(OCC) per milli curies of injected radiotracer at 1 hour and 2 hours. The correlations were evaluated between these parameters and Hoehn-Yahr classification of the patients. Results : The(BG - OCC)/OCC/mCi ratios at 1 hour and 2 hours for PD and NC were $0.14{\pm}0.07$ and $0.27{\pm}0.07$(1 hour) and $0.12{\pm}0.07$ and $0.34{\pm}0.04$(2 hour), respectively. The(BG - OCC)/OCC/mCi ratios of Parkinson's disease were decreased with higher grade of Hoehn-Yahr classification of the patients. The ratio between BG and OCC for PD were clearly separated from NC and may be useful outcome measures for clinical diagnosis. Conclusion : The findings suggest that IPT may be a very useful tracer for early diagnosis and treatment of PD and study of dopamine re-uptake site.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.2
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• pp.108-112
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• 2016

Molecular imaging with the radiolabeled RGD peptides for ${\alpha}_v{\beta}_3$ integrin has been an increasing interest for tumor diagnosis and the treatment monitoring. Recently, $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ was developed for quantification of ${\alpha}_v{\beta}_3$ integrin and its biological properties was elucidated. To better understand the molecular process in vivo, we performed the kinetic analysis for the $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$. After preparation of a radiotracer, dynamic PET images were obtained in the U87MG xenograft mice for 60 min (n = 6). Binding potential values were estimated from the 3-tissue compartment model, reference Logan and simplified reference tissue model. In the early time frame (0-20 min), the liver, kidney, intestine, urinary bladder and tumor were visualized but these uptakes were diminished as time went by. The tumors showed a good contrast at 40 min after administration. $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ showed the 2-fold uptake in the tumor compared with that in the muscle. The parametric maps for binding values also provide the higher tumor-to-background contrast than the static images. A binding value obtained from the 3-tissue compartment model was comparable to other modeling methods. From these results, we conclude that $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ may be a promising PET radiotracer for the evaluation of angiogenesis.

• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.35-46
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• 1996

Dopamine transporter concentrations have been known to decrease in Parkinson's disease (PD) or increase in Tourette's disorder. The purpose of this study was to evaluate the effectiveness of [I-123]N-(3-iodopropene-2-yl)-$2{\beta}$-carbomethoxy-$3{\beta}$-(4-chlorophenyl) tropane (IPT) as an imaging agent for measuring changes in transporter concentrations with PD. IPT labelled with 6.69+/-0.64 mCi(247.53+/-23.68 MBq) of I-123 was intravenously injected into ten patients(age: 55+/-11) with PD, and six normal controls(NC)(age: 46+/-14) as a bolus. Dynamic SPECT scans of the brain were then performed for 5 minutes each over 120 minutes on a triple headed camera. Time activity curves were generated for the left basal ganglia(LBG), right basal ganglia(RBC), and occipital cortex(OCC). The statistical parameters included the time to peak activity, the contrast ratio of LBG and RBG to OCC at several time points, and the accumulated specific binding counts/mCi/pixel(ASBC) from 0 to 115 minutes. The uptake of IPT in the brains of PD and NC peaked within 10 minutes of injection in all subjects. The maximum target to background ratio in the basal ganglia of PD and NC occurred at 85+/-20 min and 110+/-6 min of injection, respectively. The BG/OCC ratios at 115 minutes for PD and NC were 2.15+/-0.54 and 4.26+/-0.73, respectively. The ASBC at 115 minutes for PD and NC were 152.91+/-50.09 and 289.51+/-49.00, respectively. The ratio of BG/OCC for the NC was significantly higher than the ratio for PD. SPECT data matched with clinical diagnosis for PDs. The ratio between BG and OCC and the ASBC for PD were clearly separated from NC and may be useful outcome measures for clinical diagnosis. The findings suggest that IPT may be a very useful tracer for early diagnosis of PD and study of dopamine reuptake site.