• The Journal of Korean Society for Radiation Therapy
• /
• v.17 no.2
• /
• pp.141-145
• /
• 2005

Purpose : It is known that the neutron is generally generated from the photon, its energy is larger than 10 MV. The neutron is leaked in the container inspection system installed at the customs though its energy is below 9 MV. It is needed that the spacial effect of the neutrons released from radiation treatment machine, linac, installed in the medical canter. Materials and Methods : The medical linear accelerator(Clinac 1800, varian, USA) was used in the experiment. Measuring neutron was used bubble detector(Bubble detector, BDPND type, BTI, Canada) which was created bubble by neutron. The bubble detector is located on the medical linear accelerator outskirt in three different distance, 30, 50, 120 cm and upper, lower four point from the iso-center. In addition, for effect on protect material we have measured eight points which are 50 cm distance from iso-center. The SAD(source-axis-distance), distance from photon source to iso-center, is adjusted to 100 cm and the field size is adjusted to $15{\times}15cm^2$. Irradiate 20 MU and calculate the dose rate in mrem/MU by measuring the number of bubble. Results : The neutron is more detected at 5 position in 30, 50 cm, 7 position in 120 cm and with wedge, and 2 position without mount. Conclusion : Though detection position is laid in the same distance in neutron measurement, the different value is shown in measuring results. Also, neutron dose is affected by the additional structure, the different value is obtained in each measurement positions. So, it is needed to measure and evaluate the neutron dose in the whole space considering the effect of the distance, angular distribution and additional structure.

• Parasites, Hosts and Diseases
• /
• v.36 no.4
• /
• pp.249-254
• /
• 1998

In Korea, Clonorchis sinensis infection is still highly prevalent because case detection in the field is difficult and the detected cases used to be incompletely cured due to treatment failure. The present study tried to control clonorchiasis in an endemic village by repeated treatments with praziquantel every 6 months and to evaluate sonography as a diagnostic measure. By stool examinations, the egg positive rate in the endemic village was 22.7％, but it decreased to 19.6％ at 6 months. 15.1％ at 12 months, 12.2％ at 18 months, 6.3％ at 24 months, 11.4％ at 30 months, and 6.3％ at 42 months after the beginning of repeated praziquantel administration. The sonography showed 61 (49.6％) positive cases of 123 screened residents; among egg-positives the sonography positive rate was 52.2％ and among egg-negatives it was still 49％. The rate among cured cases was 64.3％ after 6 months, 50.0％ after 12 months, 50.0％ after 18 months, and 66.7％ after 24 months. In a non-endemic village, 64 residents were found egg-negative by fecal examination, but 20 (31.3％) of them were positive by sonography. The present findings indicate that control of clonorchiasis in an endemic village by repeated praziquantel treatment for 42 months is still insufficient and sonography is of little value for diagnosis of clonorchiasis.

• Journal of Trauma and Injury
• /
• v.20 no.2
• /
• pp.57-64
• /
• 2007

Purpose: Clinically, acute respiratory distress syndrome (ARDS) occurs within 72 hours after acute exposure of risk factors. Because of its high fatality rate once ARDS progresses, early detection and management are essential to reduce the mortality rate. Accordingly, studies on early changes of ARDS were started, and serum ferritin, as well the as injury severity score (ISS), which has been addressed in previous studies, thought to be an early predictive indicator for ARDSMethods: From March 2003 to March 2005, we investigated 50 trauma patients who were admitted to the intensive care unit in Dongguk University Medical Center, Gyeongju. The patients were characterized according to age, sex, ISS, onset of ARDS, time onset of ARDS, serum ferritin level (posttraumatic $1^{st}\;&\;2^{nd}$ day), amount of transfused blood, and death. Abdominal computed topography was performed as an early diagnostic tool to evaluate the onset of ARDS according to its diagnostic criteria. The serum ferritin was measured by using a $VIDAS^{(R)}$ Ferritin (bioMeriux, Marcy-1' Etoile, France) kit with an enzyme-linked fluorescent assay method. For statistical analysis, Windows SPSS 13.0 and MedCalc were used to confirm the probability of obtaining a predictive measure from the receiver operating characteristics (ROC) curve. Results: The ISS varied from 14 to 66 (mean: 33.8) whereas the onset of ARDS could be predicted with the score above 30 (sensitivity: 90.0%, specificity: 60.0%, p<0.05). On the posttraumatic $1^{st}$ day, the serum ferritin levels were measured to be from 31 mg/dL to 1,200 mg/dL (mean: 456 mg/dL), and the onset of ARDS could be predicted when the value was over 340 mg/dL (sensitivity: 80.0%, specificity: 65.0%, p<0.05). On the posttraumatic $2^{nd}$ day, the serum ferritin levels were measured to be from 73 mg/dL to 1,200 mg/dL (mean: 404 mg/dL), and the onset of ARDS could be predicted when the value was over 627 mg/dL (sensitivity: 60.0%, specificity: 92.5%, p<0.05). The serum ferritin levels and the ISS were significantly higher on the posttraumatic $1^{st}$ and $2^{nd}$ day in the ARDS group, suggesting that they are suitable indices predicting the onset of ARDS, however relationship between the serum ferritin levels and the ISS was not statistically significant. Conclusion: In this study, we discovered increasing serum ferritin levels in multiple- trauma patients on the posttraumatic $1^{st}$ & $2^{nd}$ day and concluded that both the serum ferritin level and the ISS were good predictors of ARDS. Although they do not show statistically significant relationship to each other, they can be used as independent predictive measures for ARDS. Since ARDS causes high mortality, further studies, including the types of surgery and the methods of anesthesia on a large number of patients are essential to predict the chance of ARDS earlier and to reduce the incidence of death.

• Investigative Magnetic Resonance Imaging
• /
• v.17 no.4
• /
• pp.286-293
• /
• 2013

Purpose : The objective of this study was to analyze the brain volume according to the brain image of healthy adults in the 20s taken with different inversion time (TI). Materials and Methods: Brain images of healthy adults in the 20 s were acquired using magnetization prepared rapid acquisition gradient echo (MPRAGE) pulse sequence with 1.5 mm thickness of pieces and four inversion times (1100 ms, 1000 ms, 900 ms, 800 ms). The acquired brain images were analyzed to measure the volume of white matter (WM), gray matter (GM), intracranial volume (ICV). The statistical difference according to brain volume and gender was analyzed for each TI. Results: The brain volume calculated using Freesurfer was WM$486.52{\pm}48.64cm^3$ and GM=$646.83{\pm}57.12cm^3$ in mean when adjusted by mean ICV=$1278.94{\pm}154.92cm^3$. Men's brain volume(WM, GM, ICV) was larger than women's brain volume. In the intrarater reliability test, all of the intraclass correlation coefficients were high (0.992 for WM, 0.988 for GM, and 0.997 for ICV). In the repeated measures analysis of variance, GM and ICV did not show a significant difference at each TI (GM p=0.143, ICV p=0.052), but WM showed a significant (p=0.001). In the linear structure relation analysis, all of the Pearson correlation coefficients were high. Conclusion: WM, GM, and ICV indicated high reliability and solid linear structure relations, but WM showed significant differences at each TI. The brain volume of healthy adults in the 20s could be used in comparison with that of patients for reference purposes and to predict the structural change of brain. It would be needed to conduct additional studies to examine the contract, SNR, and lesion detection ability according to variable TI.

• Microbiology and Biotechnology Letters
• /
• v.35 no.2
• /
• pp.158-162
• /
• 2007

Methicillin-resistant Staphylococcus aureus (MRSA) is one of a major nosocomial pathogen worldwide and the emergence of this strain has become a major clinical problem. This study was performed for 13 hospitals with more than 400 beds in the country by collecting samples including hands and nasal cavities of doctors, nurses, guardians and patients. Also, additional 320 samples of hands and nasal cavities of 160 community resident in different locations and regions were collected. In all of medical environments and community resident, 625 strains of S. aureus were detected. Among 625 strains of S. aureus, 585 strains(93.6%) showed the resistance to at least one kind of antimicrobial and 112 strains (17.9%) showed multi-drug resistance with the resistance to 4 different types of antimicrobial. Total 152 MRSA strains (24.3%) were isolated from medical environment and community resident. In nasal cavity and hand, 49 MRSA (19.4%) and 103 (27.6%) MRSA were isolated, respectively Minimum inhibitory concentration(MIC) test is used to measure for susceptibility of MRSA isolated to oxacillin. At a concentration $16{\mu}g/ml$ of oxacillin, 11 strains were inhibited. 32 strains at $32{\mu}g/ml$, 41 strains at $64{\mu}g/ml$, 3 strains at $128{\mu}g/ml$, 25 stains at $256{\mu}g/ml$ and 40 strains at over $256{\mu}g/ml$ were inhibited. It was considered that medical environment showed higher than livestock and marine environments in MRSA detection rate.

• Progress in Medical Physics
• /
• v.17 no.1
• /
• pp.24-31
• /
• 2006

Automated analysis software was developed to measure the magnitude of the intrafractional and interfractional errors during breast radiation treatments. Error analysis results are important for determining suitable planning target volumes (PTV) prior to Implementing breast-conserving 3-D conformal radiation treatment (CRT). The electrical portal imaging device (EPID) used for this study was a Portal Vision LC250 liquid-filled ionization detector (fast frame-averaging mode, 1.4 frames per second, 256X256 pixels). Twelve patients were imaged for a minimum of 7 treatment days. During each treatment day, an average of 8 to 9 images per field were acquired (dose rate of 400 MU/minute). We developed automated image analysis software to quantitatively analyze 2,931 images (encompassing 720 measurements). Standard deviations ($\sigma$) of intrafractional (breathing motion) and intefractional (setup uncertainty) errors were calculated. The PTV margin to include the clinical target volume (CTV) with 95% confidence level was calculated as $2\;(1.96\;{\sigma})$. To compensate for intra-fractional error (mainly due to breathing motion) the required PTV margin ranged from 2 mm to 4 mm. However, PTV margins compensating for intefractional error ranged from 7 mm to 31 mm. The total average error observed for 12 patients was 17 mm. The intefractional setup error ranged from 2 to 15 times larger than intrafractional errors associated with breathing motion. Prior to 3-D conformal radiation treatment or IMRT breast treatment, the magnitude of setup errors must be measured and properly incorporated into the PTV. To reduce large PTVs for breast IMRT or 3-D CRT, an image-guided system would be extremely valuable, if not required. EPID systems should incorporate automated analysis software as described in this report to process and take advantage of the large numbers of EPID images available for error analysis which will help Individual clinics arrive at an appropriate PTV for their practice. Such systems can also provide valuable patient monitoring information with minimal effort.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.6
• /
• pp.434-441
• /
• 2014

This study is purposed to measure airborne asbestos concentrations at demolition sites and surrounding areas of asbestos containing buildings in Seoul and examine whether the measurement results correspond with allowable exhaust standard for asbestos of the Asbestos Safety Control Act. The airborne asbestos concentrations for 37 sites were below the detection limit ($7fiber/mm^2$) in 101 (35%) out of 288 samples. The whole average airborne asbestos concentration in 37 sites was $0.003{\pm}0.002f/cc$(max 0.0013 f/cc) and almost the whole airborne asbestos concentrations were satisfied with allowable exhaust standard for asbestos, 0.01 f/cc, of the Asbestos Safety Control Act. So possibility of asbestos exposure is not yet a major concern at current levels for sites demolished of asbestos containing buildings in Seoul. Looking at each sampling point, the average airborne asbestos concentrations in boundary line of site, entrance of sanitation, around the workplace (in), around the workplace (out), negative pressure units, storage area for waste, outlet for waste and residential area of residents were respectively $0.002{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.004{\pm}0.002f/cc$, $0.005{\pm}0.004f/cc$, $0.005{\pm}0.003f/cc$ and $0.003{\pm}0.002f/cc$. As a result, all sampling points of study were satisfied with allowable exhaust standard for asbestos, 0.01 f/cc, of the Asbestos Safety Control Act.

• Childhood Kidney Diseases
• /
• v.10 no.1
• /
• pp.33-39
• /
• 2006

Purpose : Neonatal hydronephrosis is diagnosed with an incidence of 4.5-7% of pregnancies. Recently, early detection of neonatal hydroneprosis with antenatal ultrasonography has be-come possible. But consensus about its management has not been reached, especially concerning surgical intervention. The purpose of this study is to analyze the natural course of neonatal hydronephrosis and to determine the guideline of surgical intervention and follow up study. Methods : Sixty nine hydronephrotic kidneys were confirmed from April 2001 to April 2005. All cases were rechecked by ultrasonography once at least and had a minimum follow-up of 6 months. We classified the patients into 4 groups according to the anterior posterior pelvic diameter(APPD) on perinatal ultrasonography. Ultrasonography to measure the APPD diameter and Society for Fetal Urology(SFU) grade, $^{99m}Tc-MAG3$ scan were done to a set protocol. Pyeloplasty was peformed according to the protocol. Results : Pyeloplasty was not needed in most cases where the APPD was below 10 mm and where the SFU grade were less than grade 3. Many cases with APPD 10 mm above or SFU grade III above had undergone pyeloplasty. We found a correlation between obstruction grade on MAG3 scan and whether surgery was performed or not. Conclusion : If APPD is above 10 mm, SFU grade is above grade 3 or urinary tract obstruction is suspected by MAG3 scan, pyeloplasty must be considered. In cases where APPD is below 10mm and SFU grade is less than grade 3, we can observe the natural course of neonatal hydronephrosis with consecutive follow-up. (J Korean Soc Pediatr Nephrol 2006;10:33-39)

• Korean Journal of Remote Sensing
• /
• v.25 no.4
• /
• pp.383-389
• /
• 2009

The main objective of the research is a feasibility study on the intertidal zone using a X-band radar satellite, TerraSAR-X. The TerraSAR-X data have been acquired in the west coast of Korea where large tidal flats, Ganghwa and Yeongjong tidal flats, are developed. Investigations include: 1) waterline and backscattering characteristics of the high resolution X-band images in tidal flats; 2) polarimetric signature of halophytes (or salt marsh plants), specifically Suaeda japonica; and 3) phase and coherence of interferometric pairs. Waterlines from TerraSAR-X data satisfy the requirement of horizontal accuracy of 60 m that corresponds to 20 cm in average height difference while current other spaceborne SAR systems could not meet the requirement. HH-polarization was the best for extraction of waterline, and its geometric position is reliable due to the short wavelength and accurate orbit control of the TerraSAR-X. A halophyte or salt marsh plant, Suaeda japonica, is an indicator of local sea level change. From X-band ground radar measurements, a dual polarization of VV/VH-pol. is anticipated to be the best for detection of the plant with about 9 dB difference at 35 degree incidence angle. However, TerraSAR-X HH/TV dual polarization was turned to be more effective for salt marsh monitoring. The HH-HV value was the maximum of about 7.9 dB at 31.6 degree incidence angle, which is fairly consistent with the results of X-band ground radar measurement. The boundary of salt marsh is effectively traceable specifically by TerraSAR-X cross-polarization data. While interferometric phase is not coherent within normal tidal flat, areas of salt marsh where the landization is preceded show coherent interferometric phases regardless of seasons or tide conditions. Although TerraSAR-X interferometry may not be effective to directly measure height or changes in tidal flat surface, TanDEM-X or other future X-band SAR tandem missions within one-day interval would be useful for mapping tidal flat topography.

• Clinical and Experimental Reproductive Medicine
• /
• v.36 no.3
• /
• pp.187-197
• /
• 2009

Objective: Phosphorylation and dephosphorylation of proteins are important in regulating cellular signaling pathways. Bead-based multiplex phosphorylation assay was conducted to detect the phosphorylation of seven proteins to maximize the information obtained from a single lysate of stage-specific mouse oocytes at a time. Methods: Cumulus-oocyte complexes (COCs) were cultured for 2 h, 8 h, and 16 h, respectively to address phosphorylation status of seven target proteins during oocyte maturation process. We analyzed the changes in phosphorylation at germinal vesicle (GV, 0 h), germinal vesicle breakdown (GVBD, 2 h), metaphase I (MI, 8 h), and metaphase II (MII, 16 h in vitro or in vivo) mouse oocytes by using Bio-Plex phosphoprotein assay system. We chose seven target proteins, namely, three mitogen-activated protein kinases (MAPKs), ERK1/2, JNK, and p38 MAPK, and other 4 well known signaling molecules, Akt, GSK-$3{\alpha}/{\beta}$, $I{\kappa}B{\alpha}$, and STAT3 to measure their phosphorylation status. Western blot analysis and kinase inhibitor treatment for ERK1/2, JNK, and Akt during in vitro maturation of oocytes were conducted for the confirmation. Results: Phosphorylation of ERK1/2, JNK, p38 MAPK and STAT3 was increased over 3 folds up to 20 folds, while phosphorylation of the other three signal molecules, Akt, GSK-$3{\alpha}/{\beta}$, and $I{\kapa}B{\alpha}$ was less than 3 folds. All of these results except for Akt were statistically significant (p<0.05). Conclusion: This is the first report on the new and valuable method measuring many phosphoproteins simultaneously in one minute sample such as oocyte lysates. All of the three MAPKs, ERK1/2, JNK, and p38 MAPK are involved in the process of mouse oocyte maturation. In addition, STAT3 might be important regulator of oocyte maturation, while Akt phosphorylation at Serine 473 may not be involved in the regulation of oocyte maturation.