• Investigative Magnetic Resonance Imaging
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• v.22 no.3
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• pp.158-167
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• 2018

Purpose: To investigate the surgical, perfusion, and molecular characteristics of glioblastomas which influence long-term survival after treatment, and to explore the association between MR perfusion parameters and the presence of MGMT methylation and 1p/19q deletions. Materials and Methods: This retrospective study was approved by our institutional review board. A total 43 patients were included, all with pathologic diagnosis of glioblastoma with known MGMT methylation and 1p/19q deletion statuses. We divided these patients into long-term (${\geq}60\;months$, n = 7) and short-term (< 60 months, n = 36) survivors, then compared surgical extent, molecular status, and rCBV parameters between the two groups using Fisher's exact test or Mann-Whitney test. The rCBV parameters were analyzed according to the presence of MGMT methylation and 1p/19q deletions. We investigated the relationship between the mean rCBV and overall survival using linear correlation. Multivariable linear regression was performed in order to find the variables related to overall survival. Results: Long-term survivors (100% [7 of 7]) demonstrated a greater percentage of gross total or near total resection than short-term survivors (54.5% [18 of 33]). A higher prevalence of 1p/19q deletions was also noted among the long-term survivors (42.9% [3 of 7]) than the short-term survivors (0.0% [0 of 36]). The rCBV parameters did not differ between the long-term and short-term survivors. The rCBV values were marginally lower in patients with MGMT methylation and 1p/19q deletions. Despite no correlation found between overall survival and rCBV in the whole group, the short-term survivor group showed negative correlation ($R^2=0.181$, P = 0.025). Multivariable linear regression revealed that surgical extent and 1p/19q deletions, but not rCBV values, were associated with prolonged overall survival. Conclusion: While preoperative rCBV and 1p/19q deletion status are related to each other, only surgical extent and the presence of 1p/19q deletion in GBM patients may predict long-term survival.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.89-100
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• 2010

Although various methods for determination of damage threshold in rock have been suggested, clear damage thresholds were determined by some methods, but different thresholds were measured by other methods. We determined the damage thresholds in Hangdeung granite using all the methods suggested, and investigated the best methods, applicability and errors of each method. The crack initiation threshold and the crack damage threshold which are important in investigation of characteristics of crack development and failure were verified by field strength ratio method and long-term constant load test. The crack closure stress and the crack initiation stress were 57.5 MPa and 77.6 MPa, and the most exact values were yielded by crack volumetric strain. The secondary crack initiation stress was 90.6 MPa and AE event count and AE event count rate were the effective methods. The volumetric stiffness, AE event count and AE event count rate were the most effective methods for determination of crack coalescence threshold and crack coalescence stress was 110.3 MPa. The crack damage stress was 127.5 MPa and was measured correctly by volumetric stiffness and AE event count rate. The ratio between crack initiation stress and uniaxial compressive strength was 0.47 which was very similar with the FSR value of 0.46. The ratio between crack damage stress and uniaxial compressive strength was almost the same as the ratio between long-term strength and uniaxial compressive strength, indicating that the crack initiation stress and the crack damage stress measured were correct.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.37-41
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• 2012

The current standard for testing tetrodotoxin (TTX) in foodstuffs is the mouse bioassay (MBA) in Korea as in many other countries. However, this test suffers from potential ethical concerns over the use of live animals. In addition, the mouse bioassay does not test for a specific toxin thus a sample resulting in mouse incapacitation would need further confirmatory testing to determine the exact source toxin (e.g., TTX, STX, brevotoxin, etc.). Furthermore, though the time of death is proportional to toxicity in this assay, the dynamic range for this proportional relationship is small thus many samples must be diluted and new mice be injected to yield a result that falls within the quantitative dynamic range. Therefore, in recent years, there have been many efforts in this field to develop alternative assays. High performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) has been emerged as one of the most promising options. A LC-MS-MS method involves solid-phase extraction (SPE) and followed by analysis using an electrospray in the positive ionization mode and multiple reactions monitoring (MRM). To adopt LC-MS-MS method as alternative standard for testing TTX, we performed a validation study for the quantification of TTX in puffer fish. This LC-MS-MS method showed good sensitivity as limits of detection (LOD) of $0.03{\sim}0.08{\mu}g/g$ and limits of quantification (LOQ) of $0.10{\sim}0.25{\mu}g/g$. The linearity ($r^2$) of tetrodotoxin were 0.9986~0.9997, the recovery were 80.9~103.0% and the relative standard deviations (RSD) were 4.3~13.0%. The correlation coefficient between the mouse bioassay and LC/MS/MS method was higher than 0.95.

• Archives of Reconstructive Microsurgery
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• v.16 no.2
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• pp.113-118
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• 2007

Purpose: The purpose of this work was to describe the results of treatment for motor vehiclerelated crushing injuries among children and adolescents under sixteen years in Korea. Materials and Methods: A retrospective analysis was conducted of data from children who were under sixteen year and injured foot by motor vehicles. Cases were documented 1) age at the time of injury, 2) injured site, 3) the area of accident, 4) the kind of vehicle, 5) associated injuries, 6) methods of treatment for soft tissue reconstruction and 7) complications. The relationships between the area of accident and associated injuries, and the kind of vehicle and associated injuries were analyzed using Chi-square test and Fisher exact test. Results: There were 97 children who were 15 year and younger. The mean age was 7.4 years, and 65% were boys. The left foot was more dominant side of injury (57%). Seasonal variation was seen with the number of injuries peaking during the summer (43%, p<0.05). Among the vehicles, 78.3% were the large vehicles (bus, truck or van). The where of accident was more frequent at an alley or less than two lanes of traffic. But, the relationships between the place of accident and associated injury or the kind of vehicles and associated injury were not statistically significant. The associated injury were fracture or dislocation (23 cases, 35.9%), injury of tendon (21 cases, 32.8%). There were amputation or disarticulation of foot in 8 cases (8.2%) and post-traumatic deformities such as flatfoot, hindfoot varus or valus deformities by tendon injury in 7 cases (7.2%). Conclusion: More than 50% of crushing or degloving injuries of child's foot by traffic accidents happened in boys between 5 to 9 years old. The associated injury was unrelated with size of vehicles or accident place at the time of accident. But, even though foot injury happened in an alley or one lane by small vehicles, child who hurt feet by car need thorough investigation about associated injury. If a surgeon keep in mind and treat child to associated injury necessarily, can minimize complication. Microsurgical reconstruction for soft tissue defect was prior to other methods.

• The Journal of the Korean dental association
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• v.48 no.6
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• pp.469-477
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• 2010

The purpose of this study was to evaluate the effect of two dentin desensitizers and Er,Cr:YSGG laser for dentinal tubule occlusion. Twenty recently extracted single-rooted human teeth were used to obtain root dentinal fragments. The crowns were cut approximately 1mm below the cementum enamel junction(CEJ). A second cut was used to remove the apex of the root. Subsequently, a longitudinal cut was made in order to obtain 2 fragments from each root sample. The cementum from the cervical portion was removed using a high-speed diamond-coated bur in order to expose the dentin. To open dentinal tubules, forty samples were treated with 50% citric acid for 2 min and then rinsed under distilled water for 1 min. These were divided into four groups of ten samples each. The first group served as a control group. In group 2, the samples were irradiated with the Er,Cr:YSGG laser(Waterlase MD, Biolase, USA). In group 3, the samples were treated with Bisblock and ONE-STEP PLUS(Bisco, USA). In group 4, the samples were treated with Gluma comfort bond & Desensitizer(Heraeus Kulzer, Germany). All the samples were examined using Scanning electron microscopy(Hitachi, S-4700, Japan) with two different magnifications(X2000, X5000). These images were assessed by one examiner who was blind to the experimental procedure, using the index of smear layer removal. The distribution of smear layer removal grades was tested using Fisher's exact test. On the order hand, in order to evaluate the occluding effect of two dentin desensitizers and Er,Cr:YSGG laser, the number of exposed dentinal tubules was counted in each group. These were evaluated using the Kruskal-Wallis test with significance predetermined $\alpha$=0.05. There were statistically significant differences between the three groups(Er,Cr:YSGG laser, Bisblock+ONE-STEP PLUS, Gluma comfort bond & Desensitizer) and control group.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.141-151
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• 1998

Objectives: To determine whether the body weight, body mass index (BMI), and basal serum level of LH, FSH, testosterone (T), dehydroepiandrosterone sulfate (DHEA-S) are related to the ovarian response to clomiphene citrate (CC) in patients with polycystic ovarian syndrome (PCOS). Materials and Method: From January 1996 to June 1997, total 57 patients with PCOS were enrolled in the present study. Women who had other infertility factors were excluded from our study. The ovulation induction using CC was used in all patients. The patients were grouped into 50 mg group, 100 mg group, and 150 mg group according to their daily CC dose. The patients were also grouped to ovulatory and non-ovulatory group. The body weight, BMI, and basal serum level of LH, FSH, T, DHEA-S were measured in all patients on the 2nd or 3rd day of the menstrual cycle. Results were analysed with Student's t-test and Fisher's exact test. Results: The body weight and BMI of the nonovulating group were significantly higher than those of the ovulating group in all groups (50, 100, 150 mg of CC). However, there were no significant differences of the level of LH and FSH between ovulating and nonovulating groups in all CC groups (50, 100, 150 mg). The level of T of nonovulating group was significantly higher in 50 and 100 mg of CC groups, but not in 150 mg group. The level of DHEA-S of the non-ovulating group is significantly higher in 50 mg group, but not in 100 and 150 mg groups. Conclusion: The body weight and BMI could be useful predictors of ovarian response to CC in patients with PCOS, and basal T and DHEA-S also might be useful in cases of low-dose CC treatment.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.403-412
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• 2015

In this study, IPA(Importance-Performance Analysis) techniques were used to suggest improvement plans and implications for convergent medical tourism services which medical tourists can be satisfied in Medical institutions. For this study, a total of 244 questionnaires among collected data for customers who experience a medical tourism service (a health checkup) at four hospitals located in Gangneung, Gangwon Province from September 1, 2014 to October 30, 2014 was to ensure a valid sample. As a result of the experiments which conducted by paired sample t-test analysis to learn corresponding to the difference between importance and satisfaction of the medical tourism services, it shows significant differences in all entries In the importance and satisfaction of the medical tourism services. As a result of the experiments which conducted by the IPA, the importance is high awareness but among service items which satisfaction is not actually high, service items that requires intensive care in the future are derived in items of "exact medical tourism services", "rapid response to the needs of the patient", "rapid medical tourism services", "communication with medical tourism coordinator". Therefore, medical institutions may need to be arranged in the Medical Tourism Coordinator with the agility and expertise of the medical tourism.

• Advances in pediatric surgery
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• v.8 no.2
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• pp.126-132
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• 2002

Inguinal hernia is a major surgical disease in pediatric surgery, occurring in 3.5% to 5% of all mature newborns and 9% to 11% of all premature babies. The objective of this study is to analyze the predisposing factors in association with recurrences of inguinal hernias in infants and children. In the period from January 1995 to September 2001, 1,575 infants and children who had primary inguinal hernias or recurrent inguinal hernias operated on at the Department of Pediatric Surgery at Seoul National University Hospital were evaluated retrospectively. We evaluated the data by medical records and by telephone interview. The sex, age, location of hernia, comorbidity, prematurity, incarceration, interval to operation after incarceration, postoperative complications were analyzed as predisposing factors in associated with hernia recurrence. Operative findings of recurrent inguinal hernia were reviewed. The data were statistically analyzed with Pearson Chi-Square test and Fisher-exact test. A total of eighteen (1.14%) out of 1,575 patients underwent an operation due to recurrent inguinal hernia. In 5 (27.8%) out of 18 recurred patients, institution of the primary herniorrhaphy was our hospital and in the other 13 (72.2%) was outside hospital. No impact on the development of recurrences was seen for sex, age, interval to operation after incarceration, and postoperative complications. The significant predisposing factors of recurrent inguinal hernias were left inguinal hernias (p=0.002), comorbidity (p=0.002), prematurity (p=0.006), incarceration (p=0.017) and technical error of first herniorrhaphy. We expect that knowledge for predisposing factors of recurrent inguinal hernias and experienced skill of pediatric surgeons will decrease recurrence rate in primary inguinal hernia.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.187-196
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• 2005

Since the allowable bearing capacities of piles in weathered/fractured rock are mainly governed by settlement, the load-displacement behavior of pile should be known accurately. To predict pile head settlement at the design stage, the exact understanding of the load-transfer mechanisms is essential. Therefore, in this research, the load-transfer mechanism of drilled shaft socketed into weathered rock was investigated. For the investigation, five cast-in-place concrete piles with diameters of 1,000 mm were socketed into weathered gneiss. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. A comprehensive field/laboratory testing program on weathered rock at the Held test sites was also performed to describe the in situ rock mass conditions quantitatively. And then, the effect of rock mass condition on the load transfer mechanism was investigated. The f-w (side shear resistance-displacement) curve of the pile in moderately weathered rock reached to yielding point at a for millimeter displacements, and after yielding point, the rate of resistance increment dramatically decreased. However, the f-w curve in the highly/completely weathered rock did not show the obvious yielding point, and the resistance gradually increased showing the hyperbolic pattern until relatively high displacement (>15 mm). The q-w (end bearing resistance-displacement) curves showed linear response at least until the base displacement of approximately 10 mm, regardless of rock mass conditions.

• Journal of dental hygiene science
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• v.17 no.2
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• pp.183-191
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• 2017

The purpose of this study was to evaluate a clinical preventative care program, based on a dental hygiene process (accessment, diagnosis, planning, implementation, evaluation; ADPIE) in a dental clinic, by analyzing patient recognition, knowledge, practice, and satisfaction with respect to oral health. The collected data (in percentages) were analyzed Fisher's exact test and paired t-test using IBM SPSS ver. 21.0 (IBM Co., USA). This study demonstrated a significant difference in oral health knowledge, recognition, and practice before and after the clinical preventive care program (p<0.05). The results were significant in the individual preventive plan within the planning stage, and in the professional teeth cleaning implementation stage (p<0.05). This result can be attributed to the sympathy of the dental hygienist (p<0.05). There was a positive correlation between recommending dental checkups and regular checking of the (r=0.552, p<0.05), undergoing radiography (r=0.434, p<0.01), following an individual preventive plan (r=0.568, p<0.01), undergoing proximal machine teeth cleaning (r=0.437, p<0.05), following tooth brushing instructions (r=0.552, p<0.05), and the evaluation results (r=1.000, p<0.05). Our results demonstrate, that the clinical preventive care program, based on dental hygiene, is an effective program. Given the positive effect of dental revisits and patient recommendations promoting dental hygienists, it is hoped that this preventative program will be widely used.