• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.165-172
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• 2004

This study was conducted to investigate changes in physico-chemical characteristics of Hanwoo carcass according to different castration and slaughtering ages. Total 75 Hanwoo calves(average 4 months old) were randomly assigned to Control(bulIs). Treatment I. Il , III. or IV(castrated on 4. 9. 12. and 16 months of age, respectively) and slaughtered at 7. 9. 12, 16, and 28 months of age. Moisture contents in M. Longissimus dorsi of both Hanwoo bulls and steers were decreased as the slaughtering age increased. Moisture contents in all steer groups were significantly(P <0.05) lower(average 68.63%) than that in bulls(72.18%) at 28 months of age. Crude fat contents tended to increase as the slaughtering age increased. Crude fat contents in Treatment III(castrated at 12 months of age) at 28 months of age were 10.24% which was the highest among all steer groups. Crude protein contents in M. Longissimus dorsi of Hanwoo bulls were around 23% regardless of slaughtering age. Water holding capacity(WHC) of both bulls and steers tended to increase as the animals aged. Steers showed rapid increase in WHC after 16 months of age and showed higher(78.39%)) WHC than bulls(70.00%) at 28 months of age. Palmitic acid(CI8: 0) contents in Hanwoo bulls were increased as the slaughtering age increased(20.92 \longrightarrow 24.22%) whereas stearic acid(CI8: 0) contents were decreased(I8.l5 \longrightarrow11.32%). Oleic acid(CI8: I). a major unsaturated fatty acid. significantly(P <0.05) increased(25.59 \longrightarrow 37.90%) when slaughtering age of Hanwoo increased. Changes in fatty acid composition in Hanwoo steers were similar to those in bulls except oleic acid contents were higher and stearic acid contents were lower than bulls at 28 months of age.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.621-626
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• 2002

The bacteriological and physicochemical analysis of sea water and sediments in south western part of Jinhae Bay was conducted. The samples were collected from 40 stations, which were established once a month from January to December, 2000. During the study period, the range of temperature was from 5.5 to $23.7^{\circ}C$, the concentration of chemical oxygen demand ranged from 1.20 to 1.55 mg/L, dissolved oxygen ranged from 3.7 to 9.1 mg/L, dissolved inorganic nitrogen ranged from 2.79 to 7.09 $\mu$g-at/L phosphate phosphorus ranged from 0.39 to 0.57 $\mu$g-at/L, and chlorophyll-$\alpha$g-at/L ranged from 4.28 to $9.66 mg/m^{3}$. The chemical oxygen demand, acid volatile sulfide and ignition loss of sediments in south western part of Jinhae Bay ranged from 0.04 to 0.40, from 24.23 to 35.52 mg/L and from 10.49 to $11.09\%$ respectively. The coliform group and fecal coliform MPN's of sea water in south western part of Jinhae Bay ranged from <3.0 to 1,600 MPN/1003nL (means <3.0 MPN/100 mL) and from <3.0 to 93 MPN/100 mL (means <3.0 MPN/ 100 mL), respectively. The coliform group was classified with IMViC reactions were analyzed. Two hundred eighteen strains that were obtained from sea water samples in south westen of Jinhae Bay represented Escherichia coli group, $61.9\%$; Citrobacter freundii group, $12.1\%$; Enterobacter aerogenes, $14.1\%$; and unknown, $11.9\%$.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.385-396
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• 2007

The aims of this study were to compare the shaping effect and safety between single length technique recommended by manufacturer and crown-down technique using Mtwo rotary file and to present a modified method in use of Mtwo file. Sixty simulated root canal resin blocks were used. The canals were divided into three groups according to instrument and the manner of using methods. Each group had 20 specimens. Group MT was instrumented with single length technique of Mtwo, group MC was instrumented with crown-down technique of Mtwo and group PT was instrumented with crown-down technique of ProTaper. All of the rotary files used in this study were operated by an electric motor. The scanned canal images of before and after preparation were superimposed. These superimposed images were evaluated at apical 1 to 8 mm levels Angle changes were calculated. The preparation time, weight loss, instrument failure and binding, canal aberrations, and centering ratio were measured. Statistical analysis of the three experimental groups was performed with ANOVA and Duncan's multiple range tests for post-hoc comparison and Fisher's exact test was done for the frequency comparison. In total preparation time, group MT and group MC were less than group PT. In the aberrations, group MT had more elbows than those of group MC and group PT. The binding of group MC was least and group MT was less than group PT (P < 0.05). Under the condition of this study, crown-down technique using Mtwo rotary file is better and safer method than single length technique recommended by the manufacturer.

• Journal of Soil and Groundwater Environment
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• v.11 no.5
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• pp.20-34
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• 2006

This study was undertaken to assess the anthropogenic impact on trace metal concentrations (Zn, Cu, Pb, Cr, Ni, and Cd) of roadside sediments (N = 70) from No.7 national road within the watershed of Hoidong Reservoir in Pusan City and to estimate the potential mobility of selected metals using sequential extraction. We generally found high concentrations of metals, especially Zn, Cu and Pb, affected by anthropogenic inputs. Compared to the trace metal concentrations of uncontaminated stream sediments, arithmetic mean concentrations of roadside sediments were about 7 times higher for Cu, 4 times higher for Zn, 3 times higher for Pb and Cr and, 2 times higher for Ni and As. Speciation data on the basis of sequential extraction indicate that most of the trace metals considered do not occur in significant quantities in the exchangeable fraction, except for Cd and Ni whose exchangeable fractions are appreciable (average 29.3 and 25.8%, respectively). Other metals such as Zn (51.4%) and Pb (45.2%) are preferentially bound to the reducible fraction, and therefore they can be potentially released by a pH decrease and/or redox change. Copper is mainly found in the organic fraction, while Cd is highest in the exchangeable fraction, and Cr and Ni in the residual fraction. Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreases in the order of Cd>Ni>Pb>Zn>Cr>Cu. Although the total concentration data showed that Zn was typically present in potentially harmful concentration levels, the data on metal partitioning indicated that Cd, Ni and Pb pose the highest potential hazard for runoff water. As potential changes of redox state and pH may remobilize the metals bound to carbonates, amorphous oxides, and/or organic matter, and may release and flush them through drain networks into the watershed of Hoidong Reservoir, careful monitoring of environmental conditions appears to be very important.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.215-220
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• 2002

Purpose : Preoperative radiotherapy has been used to induce tumor regression and allow complete resection of rectal cancer with a sphincter preservation surgery. This study was performed to determine the effectiveness of preoperative radiotherapy for $T_2,\;T_3$ distal rectal carcinoma. Materials and Methods : From November 1995 to June 1997, fifteen patients with invasive distal rectal cancer were treated with preoperative radiotherapy followed by sphincter preservation surgery. Classification by preoperative T stage consisted of 7 $T_2$ and 8 $T_3$ tumors. Radiation therapy was delivered with 6 MV and 15 MV linear accelerator, at 1.8 Gy fractions for 5 days per week. Total radiation doses were 45 Gy to 50.4 Gy (median : 50.4 Gy). Sphincter preservation surgery was peformed $4\~6$ weeks after the completion of radiotherapy. Median follow-up was 22 months (range : $16\~37\;months$). Results : One patient $(6.7\%)$ had a complete pathologic response. Comparing the stage at the diagnostic workup with the pathologic stage, tumor downstaging of T stages occurred in 11 of 15 patients $(73.3\%)$ and $N_1$ stages occurred in 2 of 5 patients $(40\%)$. No patient developed progressive disease undergoing treatment. Two patients suffered local recurrence at 7 and 20 months, and one a distant metastasis at 30 months. No grade 3 or 4 toxicity was observed. Conclusion : Our experience suggests that preoperative radiotherapy followed by sphincter preservation surgery is well tolerated, and can significantly reduce the tumor burden for $T_2\;T_3$ distal rectal cancer.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.135-152
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• 1983

Emergency medical service is an important part of the health care delivery system, and the optimal allocation of resources and their efficient utilization are essentially demanded. Since these conditions are the prerequisite to prompt treatment which, in turn, will be crucial for life saving and in reducing the undesirable sequelae of the event. This study, taking the hyperbaric chamber for carbon monoxide poisoning as an example, is to develop a stochastic approach for solving the problems of optimal allocation of such emergency medical facility in Korea. The hyperbaric chamber, in Korea, is used almost exclusively for the treatment of acute carbon monoxide poisoning, most of which occur at home, since the coal briquette is used as domestic fuel by 69.6 per cent of the Korean population. The annual incidence rate of the comatous and fatal carbon monoxide poisoning is estimated at 45.5 per 10,000 of coal briquette-using population. It offers a serious public health problem and occupies a large portion of the emergency outpatients, especially in the winter season. The requirement of hyperbaric chambers can be calculated by setting the level of the annual queueing rate, which is here defined as the proportion of the annual number of the queued patients among the annual number of the total patients. The rate is determined by the size of the coal briquette-using population which generate a certain number of carbon monoxide poisoning patients in terms of the annual incidence rate, and the number of hyperbaric chambers per hospital to which the patients are sent, assuming that there is no referral of the patients among hospitals. The queueing occurs due to the conflicting events of the 'arrival' of the patients and the 'service' of the hyperbaric chambers. Here, we can assume that the length of the service time of hyperbaric chambers is fixed at sixty minutes, and the service discipline is based on 'first come, first served'. The arrival pattern of the carbon monoxide poisoning is relatively unique, because it usually occurs while the people are in bed. Diurnal variation of the carbon monoxide poisoning can hardly be formulated mathematically, so empirical cumulative distribution of the probability of the hourly arrival of the patients was used for Monte Carlo simulation to calculate the probability of queueing by the number of the patients per day, for the cases of one, two or three hyperbaric chambers assumed to be available per hospital. Incidence of the carbon monoxide poisoning also has strong seasonal variation, because of the four distinctive seasons in Korea. So the number of the patients per day could not be assumed to be distributed according to the Poisson distribution. Testing the fitness of various distributions of rare event, it turned out to be that the daily distribution of the carbon monoxide poisoning fits well to the Polya-Eggenberger distribution. With this model, we could forecast the number of the poisonings per day by the size of the coal-briquette using population. By combining the probability of queueing by the number of patients per day, and the probability of the number of patients per day in a year, we can estimate the number of the queued patients and the number of the patients in a year by the number of hyperbaric chamber per hospital and by the size of coal briquette-using population. Setting 5 per cent as the annual queueing rate, the required number of hyperbaric chambers was calculated for each province and for the whole country, in the cases of 25, 50, 75 and 100 per cent of the treatment rate which stand for the rate of the patients treated by hyperbaric chamber among the patients who are to be treated. Findings of the study were as follows. 1. Probability of the number of patients per day follows Polya-Eggenberger distribution. $$P(X=\gamma)=\frac{\Pi\limits_{k=1}^\gamma[m+(K-1)\times10.86]}{\gamma!}\times11.86^{-{(\frac{m}{10.86}+\gamma)}}$$ when$${\gamma}=1,2,...,n$$$$P(X=0)=11.86^{-(m/10.86)}$$ when $${\gamma}=0$$ Hourly arrival pattern of the patients turned out to be bimodal, the large peak was observed in $7 : 00{\sim}8 : 00$ a.m., and the small peak in $11 : 00{\sim}12 : 00$ p.m. 2. In the cases of only one or two hyperbaric chambers installed per hospital, the annual queueing rate will be at the level of more than 5 per cent. Only in case of three chambers, however, the rate will reach 5 per cent when the average number of the patients per day is 0.481. 3. According to the results above, a hospital equipped with three hyperbaric chambers will be able to serve 166,485, 83,242, 55,495 and 41,620 of population, when the treatmet rate are 25, 50, 75 and 100 per cent. 4. The required number of hyperbaric chambers are estimated at 483, 963, 1,441 and 1,923 when the treatment rate are taken as 25, 50, 75 and 100 per cent. Therefore, the shortage are respectively turned out to be 312, 791. 1,270 and 1,752. The author believes that the methodology developed in this study will also be applicable to the problems of resource allocation for the other kinds of the emergency medical facilities.

• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.129-135
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• 2002

Objective : The primary objective of this study was to estimate the prevalence of HBsAg-positives in the late 1990's among Korean adults. In addition, we evaluated the association of age, a residential area, a vaccination rate, a family history of chronic liver diseases and a past history of acute liver disease with the seropositivity of HBsAg, and estimated the prevalence of chronic HBV infection by follow-up for 6 month or more. Methods : A total of 10 areas, six metropolitan and four small cities, were selected. In each cities, one health screening center was selected for recruitment of study subjects. The study subjects were enrolled from a general health examination program that is provided by medical insurance companies. Questionnaires on various risk factors were administered to the study subjects. Sera was drawn and tested for HBsAg by radioimmunoassay. HBeAg and ALT were also tested for those of HBsAg positive. The HBsAg positives was retest for HBsAg 6 months later Results : Among the study subjects (n= 1816), the seroprevalence of HBsAg was 5.5% (95% CI=4.5%-6.6%), 7.4% in men (95% CI=5.8-9.4) and 3.6% in women (95% CI=2.5-5.0). A past history of acute liver disease and a family history of chronic liver diseases was shown to be risk factors for HBsAg positivity. Among the 31 HBsAg-positives, negative seroconversion rate was estimated to be 3.2%, Thus, prevalence of chronic HBV infection was estimated to be 5.3% (95% CI=3.7-6.6). Conclusion : In this study, the HBsAg seroprevalence rate was lower than that of the other studies in 1980's, particularly in young adult and women. Considering the public health importance of liver cancer and chronic liver diseases, the further effort is needed to prevent and reduce the HBV infection.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.362-367
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• 2007

A total of 5 female elk deer (220 $kg{\pm}10$ kg) were included in a study on the changes in physico-chemical properties of deer meat during storage at $4^{\circ}C$. The deers were exposed to normal pre-slaughter handling and put under anesthesia before slaughtered. The loin and leg cuts were deboned from the carcass after 24hrs slaughter. The samples weighing approximately 300 g were packaged using three packaging methods : Atmospheric packaging(A), Vacuum packaging (V) and Modified atmospheric at packaging (M: 80% $CO_2$ +20% $N_2$)and stored for 3, 7, 11, 15, 20 and 25days at $4^{\circ}$. The ability of moisture maintenance tended to be decreased with the passage of storage time, and that of the meats treated with the vacuum wrapping was lower than that with other wrapping methods. TBARS values of the meats with the regardless of treatments was increased with the passage of storage time, although the values with vacuum wrapping was lowest. VBN values of the meats with the regardless of treatments was also increased with the passage of storage time, although the values with vacuum wrapping was also lowest. The pH values of the meats with the regardless of treatments was also increased with the passage of storage time, although the values with vacuum wrapping was also lowest. For the meat softness, the value of the meats treated with atmospheric packaging was increased with the passage of storage time, but the values with vacuum wrapping and modified atmospheric packaging were respectively decreased. There were no significant differences in luminosity of leg, although loin treated with vacuum wrapping was significantly brighter than that with atmospheric packaging and modified atmospheric packaging. In general, the index of red color of the meats treated with vacuum wrapping was higher than that with atmospheric packaging and modified atmospheric packaging. The index of yellow color tended to be decreased after increment for a time with the passage of storage time, although the value with vacuum wrapping was generally higher than that with other wrapping methods.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.272-286
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• 2014

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Cheonsu Bay, West Coast of Korea. Total species number was 224 and mean density was $1,940ind./m^2$, both of which were dominated by polychaete worms (111 species and $1,213ind./m^2$). In terms of density, the major dominant species were the bivalve Theora fragilis ($280{\pm}213ind./m^2$), the polychaetes Heteromastus filiformis ($254{\pm}218ind./m^2$), Lumbrineris longifolia ($216{\pm}41ind./m^2$), Mediomastus californiensis ($158{\pm}97ind./m^2$) and the amphipod Eriopisella sechellensis ($167{\pm}100ind./m^2$). As a result of community statistics (cluster analysis and nMDS ordination), the macrobenthic community structure was classified two major groups (inner and mouth of bay) and two stations (station 2 near Ganwol dyke in spring and summer). The Benthic Pollution Index (BPI) and AZTI's Marine Biotic Index (AMBI) were applied to assess the benthic ecological status. During the sampling periods, the BPI Index values varied between 11 (bad status) and 92 (high status). On the other hand, the AMBI Index values was ranged between 1.34 (good status) and 4.39 (poor status). In conclusion, in terms of the mean BPI and AMBI Index values, the ecological status of Cheonsu Bay were moderate status (ecotone stage) and good status, respectively.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.354-374
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• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.