• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.163-170
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• 2014

Purpose : If electron, chosen for superficial oncotherapy, was applied with bolus, it could work as an important factor to a therapy result by showing a drastic change in surface dose. Hence the calculation value and the actual measurement value of surface dose of Treatment Planning System (TPS) according to four variables influencing surface dose when using bolus on an electron therapy were compared and analyzed in this paper. Materials and Methods : Four variables which frequently occur during the actual therapies (A: bolus thickness - 3, 5, 10 mm, B: field size - $6{\time}6$, $10{\time}10$, $15{\time}15cm2$, C: energy - 6, 9, 12 MeV, D: gantry angle - $0^{\circ}$, $15^{\circ}$) were set to compare the actual measurement value with TPS(Pinnacle 9.2, philips, USA). A computed tomography (lightspeed ultra 16, General Electric, USA) was performed using 16 cm-thick solid water phantom without bolus and total 54 beams where A, B, C, and D were combined after creating 3, 5 and 10 mm bolus on TPS were planned for a therapy. At this moment SSD 100 cm, 300 MU was investigated and measured twice repeatedly by placing it on iso-center by using EBT3 film(International Specialty Products, NJ, USA) to compare and analyze the actual measurement value and TPS. Measured film was analyzed with each average value and standard deviation value using digital flat bed scanner (Expression 10000XL, EPSON, USA) and dose density analyzing system (Complete Version 6.1, RIT, USA). Results : For the values according to the thickness of bolus, the actual measured values for 3, 5 and 10 mm were 101.41%, 99.58% and 101.28% higher respectively than the calculation values of TPS and the standard deviations were 0.0219, 0.0115 and 0.0190 respectively. The actual values according to the field size were $6{\time}6$, $10{\time}10$ and $15{\time}15cm2$ which were 99.63%, 101.40% and 101.24% higher respectively than the calculation values and the standard deviations were 0.0138, 0.0176 and 0.0220. The values according to energy were 6, 9, and 12 MeV which were 99.72%, 100.60% and 101.96% higher respectively and the standard deviations were 0.0200, 0.0160 and 0.0164. The actual measurement value according to beam angle were measured 100.45% and 101.07% higher at $0^{\circ}$ and $15^{\circ}$ respectively and standard deviations were 0.0199 and 0.0190 so they were measured 0.62% higher at $15^{\circ}$ than $0^{\circ}$. Conclusion : As a result of analyzing the calculation value of TPS and measurement value according to the used variables in this paper, the values calculated with TPS on 5 mm bolus, $6{\time}6cm2$ field size and low-energy electron at $0^{\circ}$ gantry angle were closer to the measured values, however, it showed a modest difference within the error bound of maximum 2%. If it was beyond the bounds of variables selected in this paper using electron and bolus simultaneously, the actual measurement value could differ from TPS according to each variable, therefore QA for the accurate surface dose would have to be performed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.323-337
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• 1999

Seafloor morphology and manganese nodule occurrence were studied in the Korea Deep-sea Environmental Study (KODES) area, northeast equatorial Pacific, to understand their relationship. Study area is composed of three elongated valleys and hills with about 100~200 m height along NNE-SSW direction. Valley region is generally flat. However, hill region is very rugged with big cliffs of about 100m height and small depressions of several tens of meters depth. Tectonic movement along the Clarion-Clipperton fracture zone, consequent formation of elongated abyssal hills and Valleys, erosion of siliceous bottom sediments by bottom currents, and dissolution of carbonate sediments on the abyssal hills below CCD result in the rugged morphology. Manganese nodule occurrence is closely related to the morphology of the study area; mostly rounded-shaped manganese nodules with about 5 cm diameter are abundant on the flat valley region, whereas irregular shaped nodules (or manganese crust) with less than 5 cm to about 1 m diameter occur on the hill. These results supports the previous reports that nodule abundance, composition, and morphology are variable both on regional and local small scales on the seafloor even within some abundant nodule provinces depending on oceanographic characteristics such as bathymetric features, surface sediment type, sediment thickness, and so on. We suggest that such oceanographic characteristics affect interrelatedly on the formation of manganese nodules, and tectonic movement of the Pacific plate ultimately constrain the nodule occurrence. A potential mining place in the KODES area seems to be the valley region, which is elongated to the NNW-SSE direction with 3-4 km width.

• Clinical and Experimental Pediatrics
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• v.49 no.5
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• pp.558-564
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• 2006

Purpose : Transcranial electromagnetic stimulation(TMS) is a noninvasive method which stimulates the central nervous system through pulsed magnetic fields without direct effect on the neurons. Although the neurobiologic mechanisms of magnetic stimulation are unknown, the effects on the brain are variable according to the diverse stimulation protocols. This study aims to observe the effect of the magnetic stimulation with two different stimulation methods on the cultured hippocampal slices. Methods : We obtained brains from 8-days-old Spague-Dawley rats and dissected the hippocampal tissue under the microscope. Then we chopped the tissue into 450 µm thickness slices and cultured the hippocampal tissue by Stoppini's method. We divided the inserts, which contained five healthy cultured hippocampal slices respectively, into magnetic stimulation groups and a control group. To compare the different effects according to the frequency of magnetic stimulation, stimulation was done every three days from five days in vitro at 0.67 Hz in the low stimulation group and at 50 Hz in the high stimulation group. After N-methyl-D-aspartate exposure to the hippocampal slices at 14 days in vitro, magnetic stimulation was done every three days in one and was not done in another group. To evaluate the neuronal activity after magnetic stimulation, the $NeuN/{\beta}$-actin ratio was calculated after western blotting in each group. Results : The expression of NeuN in the magnetic stimulation group was stronger than that of the control group, especially in the high frequency stimulation group. After N-methyl-D-aspartate exposure to hippocampal slices, the expression of NeuN in the magnetic stimulation group was similar to that of the control group, whereas the expression in the magnetic non-stimulation group was lower than that of the control group. Conclusion : We suggest that magnetic stimulation increases the neuronal activity in cultured hippocamal slices, in proportion to the stimulating frequency, and has a neuroprotective effect on neuronal damage.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.85-90
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• 1999

Purpose : The purpose of this study is to evaluate the clinical and histological results of the osteoarthritic patients who had second look arthroscopy after microfracture surgery. Materials and Methods : From Oct. 1997 to Dec. 1998, 46 patients, 48 knees were treated by microfracture technique. In the 22 patients, 24 knees, 'second-look' arthroscopies and biopsies were performed at 6 months following microfracture. Three patients were men and 19 patients were women. Average age of the patients were 58 years (range, 40-75 years). The average follow up period was 12 months(7-20 months). We analysed clinical results according to the nine-point scale. Also we observed type II collagen formation with immunohistochemical staining. Results : Clinical results were excellent in 83% and good in 17%. Among the 24 knees, more than 80% areas of chondral defect were covered with regenerated cartilage in 21 knees. Histologically, the regenerated tissue appears to be a hybrid of hyaline cartilage and fibrocartilage. Regenerated cartilage contains variable amount of type II collagen with immunohistochemical staining. Conclusion : Most of the patients had significant improvement clinically. 'Second-look' showed that the chondral defect areas were covered with newly grown grayish white tissue. Microfracture in the full thickness chondral defect provides and enriched environment for cartilaginous tissue regeneration.

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

• Radiation Oncology Journal
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• v.15 no.4
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• pp.357-367
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• 1997

Purpose : To identify variable prognostic factors and analyse failure patterns in the uterine cervix cancer after radical operation and adjuvant radio-therapy, a retrospective analysis was undertaken. Materals and Methods : I analysed one hundred and twenty four patients with uterine cervix cancer, FIGO stage IB, IIA and IIB, treated with radical hysterectomy and pelvic lymph node dissection followed by adjuvant radio-therapy between May 1985 and May 1994. Minimum follow up period was 24 months. All of them were treated with full dose external radiotherapy with linear accelerator and/or high dese rate intracavitary radiation. Results : Overall 5 year survival rate and relapse free survival rate were $75.4\%,\;73.5\%$, respectively. Significant prognostic factors by relapse free survival were wall involvement thickness, lymph node location and number, parametrium involvement, tumor size, stage, uterine body involvement, vaginal resection margin involvement. By multivariate analysis, lymph node matastasis. tumor size and vaginal resection margin involvement were significant prognostic factos. Treatment related failure were 33 cases. Locoregional failure were more likely in the stage IIB, lymph node positive or vaginal resection margin positive patients whereas distant failures were relatively more frequent in stage IB, IIA and lymph node, vaginal resection negative patients. In stage IIB, 5 year relapse free survival rate was only $56\%$ and nine of twenty two patients recurred. Conculsion : Postoperative radiotherapy results are good for patients with relatively low risk factor. But the results are poor for patients with multiple, high risk factors or stage IIB. To control recurrence for patients with high risk factors, postoperative adjuvant radiotherapy is not sufficient treatment method. To raise control rate adding other methods such as radiosensitizing agent or chemotherapy is necessary and prospectively randomized study is needed for evaluation of postoperative radiotherapy efficacy and /or other methods. And it is reasonable to treat primary radical radiotherapy for patients with stage IIB cervical cancer instead of radical operation and adjuvant radiotherapy and/or chemotherapy regimen.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.143-154
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• 2009

(Y $\times$ L) $\times$ D-crossbred gilts and barrows weighing $80.2\pm0.2$ kg were fed a "medium-energy" (ME) or "low-energy" (LE) diet (3.2 vs 3.0 M cal DE/kg) and slaughtered at 110, 125, or 138 kg, after which physicochemical and sensory quality traits of major primal cuts of resulting carcasses were analyzed, under a 2 (sex) $\times$ 2 (diet) $\times$ 3 (slaughter weight; SW) factorial arrangement of treatments. The ADG and ADFI were greater (P<0.01) in barrows than in gilts and also in 125- and 138-kg vs 110-kg SW. Moreover, ADG and gain:feed were greater in ME vs LE (P<0.01), whereas ADFI was greater in LE vs ME (P<0.01). Backfat thickness, which increased with increasing SW (P<0.01), was not affected by sex or diet. Carcass marbling score was greater (P<0.01) in gilts and LE than in barrows and ME, respectively. Carcass quality grade, which was superior in LE vs ME, was not affected by SW, whereas the yield grade decreased abruptly between 125- and 138-kg SW primarily due to the upper limit of carcass weight imposed on the A and B grades. Physicochemical characteristics including pH, drip loss, and variables pertaining to color of belly, ham, and loin were not affected significantly by any of the treatment factors, albeit statistically significant in some cases, in terms of quality criteria. In sensory evaluation, the acceptability of fresh belly was not influenced by any of the treatment factors. Marbling score of fresh ham was greater in LE vs ME (P<0.01) and tended to increase between 110- and 125-kg SW (P=0.10); in loin, the increase of this variable between the two SW was significant (P<0.01). Following cooking, LE was superior to ME in the acceptability in belly and ham, but the effect of SW was insignificant in any of the sensory quality traits evaluated in this study in any of the three major primal cuts. In conclusion, the present results suggest that SW can be increased to up to 138 kg without compromising carcass quality and that LE has some beneficial effects on quality of the whole carcass and the major primal cuts.

• Korean Journal of Digital Imaging in Medicine
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• v.16 no.1
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• pp.13-19
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• 2014

Purpose: FLAIR image is beneficial for the diagnosis of various bran diseases including ischemic CVS, brain tumors and infections. However the border between the legion of brain metastasis and surrounding edema may not be clear. Therefore, this study aims to investigate the practical benefits of delayed imaging by comparing the image from a patient with brain metastasis before a contrast enhancement and the image 10 minutes after a contrast enhancement. Materials and methods: Of the 92 people who underwent MRI brain metastases in suspected patients 13 people in three patients there is no video to target the 37 people confirmed cases, and motion artifacts brain metastases in our hospital June-December 2013, 18 people measurement position except for the three incorrect patient (male: 11 people, female: 7 people, average age: 60 years) in the target, test equipment, 3.0T MR System (ACHIEVA Release, Philips, I was 8ChannelSENSE Head Coil use Best, and the Netherlands). TR 11000 ms, TE 125 ms, TI2800 ms, Slice Thickness 5 mm, gap 5 mm, is a Slice number 21, the parameters of the 3D FFE, T2 FLAIR variable that was used to test, TR 8.1 ms, TE 3.7 ms, Slice number 240 I set to. The experiment was conducted by acquiring the FLAIR prior to contrast enhancement (heretofore referred to as Pre FLAIR), and acquiring the 3D FFE CE five minutes after the contrast enhancement, and recomposing the images in an axial plane of S/T 3mm, G 0mm (heretofore referred to as MPR TRA CE). Using the FLAIR 10 minutes after the contrast enhancement (heretofore referred to as Post FLAIR) and Pi-View, a retrospective study was conducted. Using MRIcro on the image of a patient confirmed for his diagnosis, the images before and after the contrast media, as well as the CNR and SNR of the MPR TRA CE images of the lesion and the site absent of lesion were compared and analyzed using a one-way analysis of variance. Results: CNR for Pre FLAIR and Post FLAIR were 34.35 and 60.13, respectively, with MPR TRA CE at 23.77 showing no significant difference (p<0.050). Post-experiment analysis shows a difference between Pre FLAIR and Post FLAIR in terms of CNR (p<0.050), but no difference in CNR between Post FLAIR and MPR TRA CE (p>0.050), indicating that the contrast media had an effect only on Pre FLAIR and Post FLAIR. The SNR for the normal site Pre FLAIR was 106.43, and for the lesion site 140.79. Post FLAIR for the normal site was 107.79, and for the lesion site 167.91. MPR TRA CE for the normal site was 140.23 and for the lesion site 183.19, showing significant difference (p<0.050), and post-experiment analysis shows that there was a difference in SNR only on the lesion sites for Pre FLAIR and Post FLAIR (p<0.050). There was no difference in SNR between the normal site and lesion site for Post FLAIR and MPR TRA CE, indicating no effect from the contrast media (p>0.050). Conclusions: This experiment shows that Post FLAIR has a higher contrast than Pre FLAIR, and a higher SNR for lesions, It was not not statistically significant and MPR TRA CE but CNR came out high. Inspection of post-contrast which is used in a high magnetic field is frequently used images of 3D T1 but, since the signal of the contrast medium and the blood flow is included, this method can be diagnostic accuracy is reduced, it is believed that when used in combination with Post FLAIR, and that can provide video information added to the diagnosis of brain metastases.

• The Korean Journal of Petroleum Geology
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• v.14 no.1
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• pp.1-11
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• 2008

As conventional oil and gas reservoirs become depleted, interests for oil sands has rapidly increased in the last decade. Oil sands are mixture of bitumen, water, and host sediments of sand and clay. Most oil sand is unconsolidated sand that is held together by bitumen. Bitumen has hydrocarbon in situ viscosity of >10,000 centipoises (cP) at reservoir condition and has API gravity between $8-14^{\circ}$. The largest oil sand deposits are in Alberta and Saskatchewan, Canada. The reverves are approximated at 1.7 trillion barrels of initial oil-in-place and 173 billion barrels of remaining established reserves. Alberta has a number of oil sands deposits which are grouped into three oil sand development areas - the Athabasca, Cold Lake, and Peace River, with the largest current bitumen production from Athabasca. Principal oil sands deposits consist of the McMurray Fm and Wabiskaw Mbr in Athabasca area, the Gething and Bluesky formations in Peace River area, and relatively thin multi-reservoir deposits of McMurray, Clearwater, and Grand Rapid formations in Cold Lake area. The reservoir sediments were deposited in the foreland basin (Western Canada Sedimentary Basin) formed by collision between the Pacific and North America plates and the subsequent thrusting movements in the Mesozoic. The deposits are underlain by basement rocks of Paleozoic carbonates with highly variable topography. The oil sands deposits were formed during the Early Cretaceous transgression which occurred along the Cretaceous Interior Seaway in North America. The oil-sands-hosting McMurray and Wabiskaw deposits in the Athabasca area consist of the lower fluvial and the upper estuarine-offshore sediments, reflecting the broad and overall transgression. The deposits are characterized by facies heterogeneity of channelized reservoir sands and non-reservoir muds. Main reservoir bodies of the McMurray Formation are fluvial and estuarine channel-point bar complexes which are interbedded with fine-grained deposits formed in floodplain, tidal flat, and estuarine bay. The Wabiskaw deposits (basal member of the Clearwater Formation) commonly comprise sheet-shaped offshore muds and sands, but occasionally show deep-incision into the McMurray deposits, forming channelized reservoir sand bodies of oil sands. In Canada, bitumen of oil sands deposits is produced by surface mining or in-situ thermal recovery processes. Bitumen sands recovered by surface mining are changed into synthetic crude oil through extraction and upgrading processes. On the other hand, bitumen produced by in-situ thermal recovery is transported to refinery only through bitumen blending process. The in-situ thermal recovery technology is represented by Steam-Assisted Gravity Drainage and Cyclic Steam Stimulation. These technologies are based on steam injection into bitumen sand reservoirs for increase in reservoir in-situ temperature and in bitumen mobility. In oil sands reservoirs, efficiency for steam propagation is controlled mainly by reservoir geology. Accordingly, understanding of geological factors and characteristics of oil sands reservoir deposits is prerequisite for well-designed development planning and effective bitumen production. As significant geological factors and characteristics in oil sands reservoir deposits, this study suggests (1) pay of bitumen sands and connectivity, (2) bitumen content and saturation, (3) geologic structure, (4) distribution of mud baffles and plugs, (5) thickness and lateral continuity of mud interbeds, (6) distribution of water-saturated sands, (7) distribution of gas-saturated sands, (8) direction of lateral accretion of point bar, (9) distribution of diagenetic layers and nodules, and (10) texture and fabric change within reservoir sand body.