• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1210-1219
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• 2001

Introduction : The purpose of this study was to analyze the safety, pullout strength and radiographic characteristics of unicortical and bicortical screws of cervical facet within cadaveric specimens and evaluate the influence of level of training on the positioning of these screws. Methods : Twenty-one cadavers, mean 78.9 years of age, underwent bilateral placement of 3.5mm AO lateral mass screw from C3-C6(n=168) using a slight variation of the Magerl technique. Intraoperative imaging was not used. The right side(unicortical) utilized only 14mm screws(effective length of 11mm) while on the left side to determine the length of the screw after the ventral cortex had been drilled. Three spine surgeons(attending, fellow, chief resident) with varying levels of spine training performed the procedure on seven cadavers each. All spines were harvested and lateral radiographs were taken. Individual cervical vertebrae were carefully dissected and then axial radiographs were taken. The screws were evaluated clinically and radiographically for their safety. Screws were graded clinically for their safety with respect to the spinal cord, facet joint, nerve root and vertebral artery. The grades consisted of the following categories : "satisfactory", "at risk" and "direct injury". Each screw was also graded according to its zone placement. Screw position was quantified by measuring a sagittal angle from the lateral radiograph and an axial angle from the axial radiograph. Pull-out force was determined for all screws using a material testing machine. Results : Dissection revealed that fifteen screws on the left side actually had only unicortical and not bicortical purchase as intended. The majority of screws(92.8%) were satisfactory in terms of safety. There were no injuries to the spinal cord. On the right side(unicortical), 98.9% of the screws were "satisfactory" and on the left side(bicortical) 68.1% were "satisfactory". There was a 5.8% incidence of direct arterial injury and a 17.4% incidence of direct nerve root injury with the bicortical screws. There were no "direct injuries" with the unicortical screws for the nerve root or vertebral artery. The unicortical screws had a 21.4% incidence of direct injury of the facet joint, while the bicortical screws had a 21.7% incidence. The majority of "direct injury" of bicortical screws were placed by the surgeon with the least experience. The performance of the resident surgeon was significantly different from the attending or fellow(p<0.05) in terms of safety of the nerve root and vertebral artery. The attending's performance was significantly better than the resident or fellow(p<0.05) in terms of safety of the facet joint. There was no relationship between the safety of a screw and its zone placement. The axial deviation angle measured $23.5{\pm}6.6$ degrees and $19.8{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The resident surgeon had a significantly lower angle than the attending or fellow(p<0.05). The sagittal angle measured $66.3{\pm}7.0$ degrees and $62.3{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The attending had a significantly lower sagittal angle than the fellow or resident(p<0.05). Thirty-three screws that entered the facet joint were tested for pull-out strength but excluded from the data because they were not lateral mass screws per-se and had deviated substantially from the intended final trajectory. The mean pull-out force for all screws was $542.9{\pm}296.6N$. There was no statistically significant difference between the pull-out force for unicortical($519.9{\pm}286.9N$) and bicortical($565.2{\pm}306N$) screws. There was no significant difference in pull-out strengths with respect to zone placement. Conclusion : It is our belief that the risk associated with bicortical purchase mandates formal spine training if it is to be done safely and accurately. Unicortical screws are safer regardless of level of training. It is apparent that 14mm lateral mass screws placed in a supero-lateral trajectory in the adult cervical spine provide an equivalent strength with a much lower risk of injury than the longer bicortical screws placed in a similar orientation.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.27-35
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• 2017

The purpose of this study was to investigate the features of CsI:Tl and $Gd_2O_2S$ detectors with an indirect conversion method using phantom in the DR (digital radiography) system by obtaining images of thick chest phantom, medium thickness thigh phantom, and thin hand phantom and by analyzing the SNR and CNR. As a result of measuring the SNR and CNR according to the thickness change of the subject, the SNR and CNR were higher in CsI:Tl detector than in $Gd_2O_2S$ detector when the medium thickness thigh phantom and thin hand phantom were scanned. However, when the thick chest phantom was used, for the SNR at 80~125 kVp and the CNR at 80~110 kVp in the $Gd_2O_2S$ detector, the values were higher than those of CsI:Tl detector. The SNR and CNR both increased as the tube voltage increased. The SNR and CNR of CsI:Tl detector in the medium thickness thigh phantom increased at 40~50 kVp and decreased as the tube voltage increased. The SNR and CNR of $Gd_2O_2S$ detector increased at 40~60 kVp and decreased as the tube voltage increased. The SNR and CNR of CsI:Tl detctor in the thin hand phantom decreased at the low tube voltage and increased as the tube voltage increased, but they decreased again at 100~110 kVp, while the SNR and CNR of $Gd_2O_2S$ detector were found to decrease as the tube voltage increased. The MTF of CsI:Tl detector was 6.02~90.90% higher than that of $Gd_2O_2S$ detector at 0.5~3 lp/mm. The DQE of CsI:Tl detector was 66.67~233.33% higher than that of $Gd_2O_2S$ detector. In conclusion, although the values of CsI:Tl detector were higher than those of $Gd_2O_2S$ detector in the comparison of MTF and DQE, the cheaper $Gd_2O_2S$ detector had higher SNR and CNR than the expensive CsI:Tl detector at a certain tube voltage range in the thick check phantom. At chest X-ray, if the $Gd_2O_2S$ detector is used rather than the CsI:Tl detector, chest images with excellent quality can be obtained, which will be useful for examination. Moreover, price/performance should be considered when determining the detector type from the viewpoint of the user.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.189-196
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• 2014

In Korea, over 4,700 animal carcass disposal sites were installed until 2011 due to the outbreak of foot and mouth disease. Due to the putrefaction of buried animals, the leachate containing veterinary antibiotics may release into surrounding environments. Antibiotic residues in the environment cause the formation of antibiotic resistance bacteria threatening human and ecosystem health. This study reports the concentrations of five antibiotics, including tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC), sulfamethazine (SMZ), and sulfamethoxazole (SMX), in soils from animal carcass disposal site and adjacent agricultural field. Concentrations of antibiotics at animal carcass disposal sites (TC: $144.26-350.73{\mu}g/kg$, SMZ: $17.72-44.94{\mu}g/kg$) were higher than those at agricultural field (TC: $134.16-320.73{\mu}g/kg$, SMZ: $6.48-8.85{\mu}g/kg$) whereas the concentrations of CTC, OTC, and SMX were below detection limit in both sites. Results showed that the antibiotics in animal carcass site might leach to the soil and possibly contaminating the groundwater. Future studies will focus on the transfer of antibiotics residues into food crops.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.384-389
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• 2010

Outbreak of contagious diseases to livestock animals is becoming prevalent worldwide and consequently, tremendous numbers of the infected or culled stocks are buried on the ground as the most common disposal method. The buried animals can generate a wide range of detrimental components such as leachate, nutrient salts, and pathogenic bacteria, consequently contaminating the surround environment. This implies that regular investigations are required to monitor any possible detrimental environmental aspect occurred around burial sites. Therefore, the current study was conducted to investigate whether the soil and groundwater nearby the burial sites had been contaminated by the substances originated from the burial sites, which can be applied for the establishment of the ideal burial site construction design and post management scheme. For this, two different burial sites located in Cheonan and Pyeongtaek were selected. Cheonan and Pyeongtaek sites were constructed in 2004 and 2008, respectively and both contained dead poultry infected by avian influenza (AI). Soil and groundwater samples were collected around the sites followed by determination of the nutrient concentrations and bacteria (Salmonella, Camphylobacter, and Bacillus) existence in both soil and groundwater. Some of the soil samples showed higher EC, $NH_4$-N, $NO_3$-N concentration compared to those of the background (control) soils. Also the concentration of $NH_4$-N in some of the groundwater samples appeared to exceed the USEPA guideline value for drinking water (10 mg $L^{-1}$). These results indicated that the soil and groundwater were influenced by the burial site originated nutrients. In the soil, Bacillus was isolated in most soil samples while there were no detections of Salmonella and Camplylobacter. Due to the Bacillus existing mainly as a spore in the soils, it was considered that the frequent detection of Bacillus in the soil samples was attributed to the nutrients originated from the burial sites.

• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.26-35
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• 2013

Outbreak of animal infectious diseases such as foot-and-mouth disease, avian influenza are becoming prevalent worldwide. For prevent the further infection, tremendous numbers of the infected or culled stocks are buried around farm. This burial method can generate a wide range of detrimental components such as leachate, nutrient, salt, and pathogenic bacteria, consequently. In this study, for the stabilization of livestock carcasses leachate, advanced oxidation processes utilizing the Fenton reaction was investigated in lab-scale experiments for the treatment for $COD_{Cr}$ of livestock carcass leachate. $COD_{Cr}$ reduction by the Fenton oxidation was investigated response surface methodology using the Box-Begnken methods were applied to the experimental results. A central composite design was used to investigate the effects of the independent variables of pH ($x_1$), dosage of $FeCl_2{\cdot}4H_2O$ ($x_2$) and dosage of $H_2O_2$ ($x_3$) on the dependent variables $COD_{Cr}$ concentration ($y_1$). A 1 M NaOH and $H_2SO_4$ was using for pH control, $FeCl_2{\cdot}4H_2O$ was used as iron catalyst and NaOH was used for Fenton reaction. The optimal conditions for Fenton oxidation process were determined: pH, dosage of $FeCl_2{\cdot}4H_2O$ and dosage of $H_2O_2$ were 3, 0.6 g (0.0151 M) and 7 mL(0.259 M), respectively. Statistical results showed the order of significance of the independent variables to be pH > initial concentration of ferrous ion > initial concentration of hydrogen peroxide.

• Quality Improvement in Health Care
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• v.11 no.1
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• pp.32-45
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• 2004

Objective : The aim of this study were to measure quality of life(QOL) in liver transplant recipients, to compare QOL between living donor liver transplant recipients and cadaveric liver transplant recipients and to investigate whether SF-36 may be used as a disease-specific instrument in liver transplant recipients. Methods : We conducted a single-center cross-sectional study of 133 LT recipients ages 13 to 65 years, all of whom had had Liver Transplantation(LT) at least 1 months previously. QOL was assessed using a self-completion questionnaire consisting of the Bang Whal Ran(1991) instruments and the 36-Item Short-Form Health Survey(SF-36) health status profile measure. We investigated whether the SF-36 instrument may be used as a disease-specific instrument in LT recipients. Individual scale scores range from 0 to 100, with higher score reflecting better health. Data on demographics, clinical status at pre transplantation 1 day, post transplantation clinical status, and graft function were collected to identify predictors of post transplantation QOL. Results : Standard measures for test-retest reliability, internal consistency, and discriminant and concurrent validity were examined. The reliability of the SF-36, as measured by test-retest correlation(Pearson coefficients: 0.729, p=0.002) and by internal consistency(Cronbach's alpha: 0.9431) exceeded conventional acceptability criteria. The correlation between domain scores of SF-36 and the Bang Whal Ran(l991) was clear and logical in that the clinical characteristics of SF-36 strongly correlated with the clinical component summary score of the Bang Whal Ran(l991)(r = 0.8155, P<.01). SF-36 scale scores were compared between Cadaveric Liver Transplant recipients and Living Donor Liver Transplant recipients. Donor types of post LT did not influence HRQOL(p>0.05). 87% of the liver transplant recipients were satisfied to get LT. Satisfaction of post LT showed significantly greater HRQOL(p<0.001). Conclusion : SF-36 is found reliable and valid. This study indicates thet Donor Type did not influence HRQOL after LT. The information gained from this study will help us to better define expectations and the clinical course after liver transplantation to patients and their families.

• Quality Improvement in Health Care
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• v.11 no.1
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• pp.4-14
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• 2004

Background : To examine the problems involved in writing practice of death certificates, we compared the determination of underlying cause of death for vital statistics using recorded underlying cause of death in issued death statistics. Methods : We collected 688 mortality certificates issue in year of 2,000 from 3 university hospitals. And we also collected vital statistics from ministry of statistics. The causes of death were coded by experienced medical record specialists. And causes of death determined at ministry of statistics for national vital statistics were mapped to causes of death recorded at each death certificates. The rate that underlying causes of death for vital statistics were derived from underlying causes of death recorded at issued death certificates were analysed. Results : 64.5% of underlying cause of death for could be derived from underlying cause of death recorded at issued death certificates, 8.6% derived from intermediate cause of death, and 3.9% derived from direct cause of death. In 23% of cases, underlying cause of death could not be derived using issued death certificates. The rate that underlying cause of death for vital statistics could be derived from underlying cause of death recorded at death certificates was different between 3 university hospitals. And the rate was also different between death certificates and postmortem certificates. We classified the causes of death using 21 major categories. The rate was different between diseases or conditions that caused death too. Conclusion : When we examined the correctness of death certificate writing practice using above methods, correctness of writing could not be told as satisfactory. There was difference in correctness of writing between hospitals, between death certificates and postmortem certificates, and between diseases and conditions that caused death. With this results, we suggested some strategy to improve the correctness of death certificate writing practice.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.107-121
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• 2020

The performance analysis of the small satellites launch vehicle using the electric pump cycle as the upper stage engines was performed. The first stage is the launch vehicle that uses the test launch vehicle of the Korea Space Launch Vehicle II and the second stage employs elecpump cycle engine that uses liquid methane and kerosene (RP-1) as fuel. A model for the mass estimation was presented and the analysis was conducted for the range of thrust of 20 to 40 kN and combustion pressure of 3 to 6 MPa with a nozzle expansion ratio of 60 to 100. The mixture ratio with the maximum velocity increment was calculated and the performance of the LEO and SSO payload were calculated from the stage mass estimation. In both the cases, liquid methane, and RP-1 showed maximum payload for 20 kN thrust, 3 MPa combustion pressure, and the nozzle expansion ratio of 100, with a mixture ratio of 3.49 for liquid methane and 2.75 for RP-1. In addition, the ditching points of the first stage and the fairing in the LEO mission were analyzed using ASTOS.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.523-530
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• 2014

One juvenile raptor which was not able to be identified due to its head damage was discovered on a roadside in Janggok-ri, Jori-eup, Paju on 28th June, 2011. The species was identified by DNA barcoding. After polymerase chain reaction (PCR) of the mitochondrial cytochrome c oxidase subunit I gene (COI), we obtained 695 bp sequences. We analyzed the obtained COI sequence with similar sequences from the BOLD systems and BLAST of the NCBI Genbank, and discovered that its sequence showed 100 % similarity values with the one of the five gray-faced buzzards which were previously researched. In addition, it was confirmed to be a female through sex determination using DNA. Such results are important information as it confirms the breeding of the gray-faced buzzards for the first time in 43 years since its breeding was last recorded in 1968, in Paju. Wildlife rescue center needs to work with adjacent consigned registration and preservation institutions when carcass of wild animals is collected or DNA samples are obtained for more accurate both species and sex identification through a systematic management system in the future. Furthermore, the obtained DNA sample of the gray-faced buzzard and COI gene, DNA barcode, could be used as reference standards for similar researches in the future.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.125-131
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• 2020

As technology advances, the importance of software education is increasing. Accordingly, interest in information subjects is increasing, but intending elementary learners to show algorithms only for specialized IT skills that could spoil the interest. In this paper for the elementary school students, through the four stages, 2015 revision curriculum analysis, creating of training program development operating plans, applying programs for the targeting students and analysis of results and evaluation, using Rich Picture technique which is various tools such as pictures and speech bubble symbols for the learners can express the intelligent CCTV algorithm freely and easily so they can understand fully about the algorithm of intelligent CCTV that uses artificial intelligence to extract faces from subjects. Suggest on this paper, the proposal of educational program can help the learner to grasp the principle of the algorithm by using the flowchart. As the result, Through the modification and development of the proposed program, we will conduct research on IT creative education that can be applied in various areas.