• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.241-248
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• 2009

Kaolinite was synthesized from amorphous $SiO_2$ and $Al(OH)_3{\cdot}xH_{2}O$ as starting materials by hydrothermal reaction conducted at $250^{\circ}C$ and $30\;kg/cm^2$. The acidity of the solution was adjusted at pH 2. The synthesized kaolinite was characterized by XRD, IR, NMR, FE-SEM, TEM and EDS to clarify the formational process according to the reaction time from 2 to 36 hours. X-ray diffraction patterns showed after 2 h of reaction time, the starting material amorphous $Al(OH)_3{\cdot}xH_{2}O$ transformed to boehmite (AlOOH) and after the reaction time 5 h, the peaks of boehmite were observed to be absent thereby indicating the crystal structure is partially destructed. Kaolinite formation was identified in the product obtained after 10 h of reaction and the peak intensity of kaolinite increased further with reaction time. The results of TGA and DTA revealed that the principal feature of kaolinite trace are well resolved. TGA results showed 13 wt% amount of weight loss and DTA analysis showed that exothermic peak of boehmite observed at $258^{\circ}C$ was decreased gradually and after 10 h of reaction time, it was disappeared. After 5 h of the reaction time, the exothermicpeak of transformation to spinel phase was observed and the peak intensiy increased with reaction time. The results of FT-IR suggested a highly ordered kaolinite was obtained after 36 hours of reaction. It was identified by the characteristic hydroxide group bands positioned at 3,696, 3670, 3653 and $3620\;cm^{-1}$. The development of the hydroxyl stretching between 3696 and $3620\;cm^{-1}$, depends on the degree of order and crystalline perfection. TEM results showed that after 15 h reaction time, curved platy kaolinite was observed as growing of (001) plane and after 36 h, the morphology of synthetic kaolinite exhibited platy crystal with partial polygonal outlines.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.428-437
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• 2000

Background : Five year survival rate of postoperative stage I non-small cell lung cancer(NSCLC) reaches to 66%. In the remaining one third of patients, however, cancer recurs and the overall survival of NSCLC remains dismal. To evaluate clinical and pathologic characteristics of recurred NSCLC, the patterns and factors for postoperative recurrence in patients with staged I and II NSCLC were studied. Method : A retrospective analysis was performed in 234 patients who underwent radical resection for pathologic stage I and II NSCLC. All patients who were followed up for at least one year were included in this study. Results : 1) There were 177 men and 57 women The median age was 63. The median duration of the follow up period was 732 days (range 365~1,695 days). The overall recurrence rate was 26.5%, and the recurrence occurred $358.8{\pm}239.8$ days after operation. 2) The ages of recurred NSCLC patients were higher ($63.2{\pm}8.8$ years) than those of non-recurred patients ($60.3{\pm}9.8$ years)(p=0.043). The recurrence rate was higher in stage II (46.9%) than in stage I (18.8%) NSCLC p<0.001. The size of primary lung mass was larger in recurred ($5.45{\pm}3.22\;cm$) than that of non-recurred NSCLC ($3.74{\pm}1.75\;cm$, p<0.001). Interestingly, there were no recurrent cases when the resected primary tumor was less than 2cm. 3) Distant recurrence was more frequent than locoregional recurrence (66.1% vs. 33.9%). Distant recurrence rate was higher in females and in cases of adenocarcinoma. Brain metastasis was more frequent in patients with adenocarcinoma than in those with squamous cell carcinoma (p=0.024). Conclusion: The tumor size and stage were two important factors for determining the possibility of a recurrence. Because distant brain metastasis was more frequent in patients with adenocarinoma, a prospective study should be conducted to evaluate the effectiveness of preoperative brain imaging.

• Tuberculosis and Respiratory Diseases
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• v.49 no.4
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• pp.474-485
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• 2000

Background : Current studies on multimodal strategy for N2 non-small cell lung cancer are being high interest, have drawn much attention. N2 lung cancer, however, is composed of is divided into several sub groups with that have different prognoses. The prognostic factors still remain controversial. Methods : Between January 1990 and June 1999, 180 patients with N2 lung cancer who underwent surgical resection were investigated, excluding 10 of these for surgical mortality. All patients underwent mediastinal lymph node dissection. 20 clinicopathologic factors were investigated by univariable and multivariable analyses to identify significant prognostic factors among resected N2 disease. Results : The overall 5-year survival rate was 20.6%. Multivariable analyses among overall patients revealed 3 significant prognostic factors : Age, Histologic type, Vascular invasion. Based on the result, 49 patients with both age more than 60 and pathologic Non-squamous cell showed a 5-year survival of 5.0%, whereas 37 patients with neither of the factors showed a 5-year survival of 56.6%(p<0.001). And 12 patients with both vascular invasion and pathologic Non-squamous cell showed a 5-year survival of 11.9%, whereas 67 patients with neither of the factors showed a 5-year survival of 33.6%(p=0.01). Conclusion : The prognosis of surgically resected N2 disease varies according to the 3 significant prognosis factors. Tumor size may be an additional influencing factor in the prognosis of N2 disease.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.537-546
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• 2019

Purpose: Anteromedial (AM), posterolateral (PL), anterior, and posterior remnant preserving anterior cruciate ligament (ACL) reconstructions were conducted on patients with partial ACL tears based on the arthroscopic findings. The clinical results of the four groups were compared. Materials and Methods: This study included 98 patients who underwent a remnant preserving ACL reconstruction from January 2013 to June 2016 and could be followed-up for at least two years. The subjects were categorized into four groups according to the selective bundles reconstructed: group A, anteromedial selective bundle reconstruction; group B, posterolateral selective bundle reconstruction; group C, anterior bundle reconstruction; and group D, posterior bundle reconstruction. The preoperative and postoperative anterior translation from the stress X-ray, International Knee Documentation Committee Subjective Knee Form (IKDC SKF) score, Lysholm score, and hospital for special surgery (HSS) score were compared. Results: All four groups showed significant improvement in anterior translation on the stress X-ray conducted with knees at 15° flexion, IKDC SKF score, Lysholm score, and HSS score postoperatively (in all groups, p<0.001). No intergroup differences were observed in terms of the functional outcomes except that preoperative IKDC SKF score was higher in the C group than in the A group (p=0.021), and the preoperative Lysholm score was higher in the B group than in the A group (p=0.03). Conclusion: After the AM, PL, anterior, and posterior remnant preserving ACL reconstructions, all four groups showed satisfactory results in terms of the anteroposterior stability and functional knee scores with no significant intergroup differences.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.33-46
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• 2010

We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.

• The Journal of the Korean dental association
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• v.55 no.2
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• pp.156-164
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• 2017

Purpose: The aim of this in vitro study was to assess changes in remineralization by stimulated human saliva over a short period of 48 hours with quantitative light-induced fluorescence (QLF) technology. Materials and Methods: Bovine incisor surfaces were demineralized for 10 days. Two types of stimulated saliva were collected from 7 healthy persons. 24 hours after tooth brushing (Stimulated saliva group) and immediately after tooth brushing with 1,000 ppm NaF dentifrice (Dentifrice saliva group). The specimens were immersed in saliva and fluorescence images were obtained by QLF-digital (QLF-D $biluminator^{TM}$,) at 2, 4, 6, 12, 24, and 48 hours fluorescence loss (${\Delta}F%$) of the lesions. A paired t-test was performed to assess fluorescence differences between before (${\Delta}F_{baseline}$) and after (${\Delta}F_{treatment\;time}$) the remineralization process. Results: Before the remineralization, the mean ${\Delta}F_{baseline}$ of the initial demineralized specimens was $-18.42{\pm}0.15$ (%). In both groups, the ${\Delta}F$ values obtained at baseline and after 2 hours were statistically significant (P < 0.001), indicating recovery of the lesions by approximately 40% after 2 hours. After 48 hours, remineralization rates were slightly higher (49%) for the stimulated saliva group than for the dentifrice saliva group (41%), but the difference was not statistically significant. Conclusions: With QLF minute degrees of remineralization by saliva can be measured in periods as short as 2 hours. Additionally no significantly higher effects of remineralization were observed in the dentifrice saliva group when compared to the stimulated saliva group.

• Radiation Oncology Journal
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• v.35 no.3
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• pp.233-240
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• 2017

Purpose: To validate the 8th edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system for human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) and investigate whether a modified classification better reflects the prognosis. Materials and Methods: Medical records of patients diagnosed with non-metastatic HPV-related OPSCC between 2010 and 2016 at a single institution were retrospectively reviewed. HPV status was determined by immunohistochemical analysis of p16 and/or HPV DNA polymerase chain reaction (PCR). We reclassified TNM stage T0-1 and N0-1 as group A, T2-3 or N2 as B, and T4 or N3 as C. Survival analysis according to 8th AJCC/UICC TNM staging and the modified classification was performed. Results: Of 383 OPSCC patients, 211 were positive for HPV DNA PCR or p16. After exclusion, 184 patients were included in this analysis. Median age was 56 years (range, 31 to 81 years). Most primary tumors were in the palatine tonsil (148 tumors, 80%). The eighth AJCC/UICC TNM classification could not differentiate between stage I and II (p = 0.470) or II and III (p = 0.209). Applying modified grouping, the 3-year overall survival rate of group A was significantly higher than that of group B and C (98% vs. 91%, p = 0.039 and 98% vs. 78%, p < 0.001, respectively). Differentiation between group B and C was marginally significant (p = 0.053). Conclusion: The 8th AJCC/UICC TNM staging system did not clearly distinguish the prognosis of stage II from that of other stages. Including the T2N0-1 group in stage II may improve prognostic stratification.

• Reproductive and Developmental Biology
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• v.36 no.3
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• pp.213-217
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• 2012

The decreased fertility is frequently thought to be problem of cattle production. However, studies figure out that number of these problems is related to bull factors especially in artificial insemination setting. Therefore, this study was designed to investigate the fertility status of bull by their estimated relative conception rate of cows that were inseminated by frozen semen from Korean proven bulls. Here we use the non-return rate (NRR) to access the bull fertility whereas, the NRR was define as the proportion of bulls that semen were used to inseminate cows and the number of cows that did not return for another service within 60 days. The data from 54,388 artificial inseminations (AI) were analyzed from 88 KPN semen. The NRRs of highest and lowest fertile bull were 83.81 and 51.33%, respectively. And mean NRR was 68.27%. In comparison to previously reported study, our data shows 17.38% higher NRR and the absolute value of difference in 50%>NRR and 50%

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.1
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• pp.1-10
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• 2016

The objective of this study was to investigate the effects of farming methods on mass balance from paddy rice. The experiment fields were established at Chunpo-myeon, Iksan-si in the Saemangeum watershed. Experiment was performed during the growing season to assess water and mass balances of the study field in 2013. The three different farming practices were applied: conventional (TR-A), drainage outlet heighten (TR-B) and slow release fertilizer use (TR-C). Drainage amount from TR-B was reduced by 28.5 % compared to the TR-A, while the amount from TR-C was similar to that of TR-A. Overall, nutrient concentration of paddy water were similar among the treatments except for T-P. Mean T-P concentration from TR-C was lower than that from TR-A (p-value<0.05). As the results of mass balance, TR-B appeared to reduce nutrient surface loss, substantially by 30.9 % and 40.8 % for T-N and T-P an compared to TR-A. TR-C treatment also demonstrated nutrient load reduction by 38.2 % and 40.1 % for T-N and T-P. The study results showed that water and fertilizer treatments are effective in surface load reduction respectively from paddy fields, and, long-term monitoring and evaluation is needed to confirm the reduction.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.199-206
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• 1997

Object：The purpose of this study was to investigate frequency and risk factor of violence toward parents seen in adolescents. We also want to apply this data toward developing a prevention program for adolescent violence. Method：A total of 1,345 students from 5 middle schools in Seoul, participated in this study：675 males, 670 females. We administered self-reporting questionnaire including violence toward parents, exposure to violence, family history of alcoholism, substance abuse of adolescetnt and dermographic data etc. Result：The frequency of boys’ violence toward parent was 2.8%, which was significantly higher than girls’(p<0.001). The frequency of violence toward the father was higher than the mother. The risk factors for violence toward parents were sex, parental alcohol problem, adolescent alcohol-smoking-drug problem, exposure to violence at home in the last year and exposure to violence in the life(p<0.0001). The grade, punishment, socioeconomic status, educational level of parent were not significantly related to violence toward parents. Conclusion：These suggest that adolescent violence toward parents is not rare problem any more and preventive intervention is needed for high-risk groups, that is related with experience domestic violence, substance abuse, alcoholic parent.