• Korean Journal of Radiology
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• v.24 no.1
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• pp.51-61
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• 2023

Objective: To develop and test a machine learning model for classifying human papillomavirus (HPV) status of patients with oropharyngeal squamous cell carcinoma (OPSCC) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET-derived parameters in derived parameters and an appropriate combination of machine learning methods in patients with OPSCC. Materials and Methods: This retrospective study enrolled 126 patients (118 male; mean age, 60 years) with newly diagnosed, pathologically confirmed OPSCC, that underwent ¹⁸F-FDG PET-computed tomography (CT) between January 2012 and February 2020. Patients were randomly assigned to training and internal validation sets in a 7:3 ratio. An external test set of 19 patients (16 male; mean age, 65.3 years) was recruited sequentially from two other tertiary hospitals. Model 1 used only PET parameters, Model 2 used only clinical features, and Model 3 used both PET and clinical parameters. Multiple feature transforms, feature selection, oversampling, and training models are all investigated. The external test set was used to test the three models that performed best in the internal validation set. The values for area under the receiver operating characteristic curve (AUC) were compared between models. Results: In the external test set, ExtraTrees-based Model 3, which uses two PET-derived parameters and three clinical features, with a combination of MinMaxScaler, mutual information selection, and adaptive synthetic sampling approach, showed the best performance (AUC = 0.78; 95% confidence interval, 0.46-1). Model 3 outperformed Model 1 using PET parameters alone (AUC = 0.48, p = 0.047) and Model 2 using clinical parameters alone (AUC = 0.52, p = 0.142) in predicting HPV status. Conclusion: Using oversampling and mutual information selection, an ExtraTree-based HPV status classifier was developed by combining metabolic parameters derived from ¹⁸F-FDG PET/CT and clinical parameters in OPSCC, which exhibited higher performance than the models using either PET or clinical parameters alone.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1017-1022
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• 2002

$(Ba_{1-x}Ca_x)(Ti_{1-y}Zr_y)O_3(BCTZ)$ powders for the Ni-electrode Multilayer Ceramic Capacitor(MLCC) were synthesized via hydrothermal treatment using mixed aqueous solutions of $BaCl_2{\cdot}2H_2O,\Ca(NO_3)2{\cdot}4H_2O,\ ZrOCl_2{\cdot}8H_2O$ and $TiCl_4$. Two component and three component systems were also extensively studied for basic data. BT, CT and BZ powders were crystalline but CZ was determined to be amorphous under the same synthetic condition. In BTZ system, Zr and Ti were completely soluble and Ca would be substituted for Ba up to ∼6 mol% in BCT. The submicron-sized $(Ba_{0.95}Ca_{0.05})(Ti_{0.80}Zr_{0.20})O_3$ powder of the target composition was successfully synthesized at $150{\circ}$ for 12h.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.2
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• pp.69-74
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• 2020

PIB is the first amyloid plaque PET image tracer reported for the first time in 2003, and is considered to be the best and is still being utilized due to its very high uptake and kinetic properties. Initially, it was synthesized by radioisotope labeling using a precursor containing a methoxy methyl protection group, but now it is synthesized using a 6-OH precursor that can be easily synthesized in one step using [¹¹C]methyl triflate. Carbon-11 has several limitations in clinical studies using PET because its half-life is as short as 20 minutes. In this study, in order to overcome the difficulty of this half-life, a rapid method using Sep-Pak was adopted instead of HPLC purification to significantly reduce the burden of the purification process and attempted synthesis. As a result, the synthesis time was shortened by more than 50%, and the yield of the final compound was higher than the previous result and showed relatively high specific radioactivity, confirming that it is a strategic method with high applicability for various precursors having primary amines.

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.85-90
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• 2010

Purpose: The goals of a blow-out fracture reconstruction are to restore the osseous continuity, provide support for the orbital contents and prevent functional and anatomic defects. Over the past several years, a range of autogenous and synthetic implants have been used extensively in orbital reconstructions. None of these implants have any absolute indications or contraindications in certain clinical settings. However, in extensive blow-out fractures, it is difficult to restore support of the orbital contents, which can cause more complications, such as enophthalmos. This study examined the clinical outcomes of extensive or comminuted blow-out fractures that were reconstructed by the simultaneous use of a titanium mesh plate and $Medpor^{(R)}$. Methods: Eighty six patients with extensive orbital fractures, who were admitted between March 1999 and February 2007, were reviewed retrospectively. The patients' chart and CT were inspected for review. Twenty three patients were operated on with both a titanium mesh plate (Matrix MIDFACE pre-formed orbital plate, Synthes, USA) and $Medpor^{(R)}$ (Porex, GA, USA). The patients underwent pre-operative CT scans to evaluate the fracture site and measure the area of the fracture. A transconjunctival approach was used, and titanium mesh plates were inserted subperiosteally with screw fixation. $Medpor^{(R)}$ was inserted above the titanium mesh plate. The patients were evaluated post-operatively for enophthalmos, diplopia, sensory disturbances and eyeball movement for a period of at least 6 months. Results: No implant-related complications were encountered during the follow-up period. Enophthalmos occurred in 1 patient, 1 patient had permanent sensory disturbance, and 3 patients complained of ocular pain and fatigue, which recovered without treatment. Although there were no significance differences between groups, the use of 2 implants had fewer complications. Therefore, it can be an alternative method for treating blow out fractures. Conclusion: The use of both a titanium mesh plate and $Medpor^{(R)}$ simultaneously may be a safe and acceptable technique in the reconstruction of extensive blow-out fractures.

• Journal of Conservation Science
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• v.35 no.3
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• pp.253-258
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• 2019

The gilt bronze statue, Seated Avalokiteshvara with a Thousand Hands, of the Goryeo dynasty, is the only one in Korea of its kind that has undergone a conservation process for the special exhibition entitled GORYEO: The Glory of Korea. For the conservation treatment, first, a component analysis (XRF) was conducted, and a manufacturing technique (CT) was analyzed. The results of the investigation revealed that the statue was alloyed with Cu, Sn, and Pb ternary bronze. Its surface, except for the detached plating layers, was originally plated using the mercury amalgam method. This statue was assembled after separately casting each part of the body, such as the left and right arms and the wrists, including the hands, with objects. In particular, each wrist was cast and fitted with a metal nail to express each object in the hands more precisely. Inside the statue, there were five iron cores: two for the head, one for the left elbow, one for the right flank, and one for the right waist. For the preservative treatment, natural adhesive agents, including vegetable gelatin and glue (20%), were mixed with alcohol to protect the base metal and adhere to the plating layers. Using synthetic resin (CDK 520+SN-sheet) for the damaged parts, the restored parts could be attached and detached to/from the statue. Eventually, the compositional analysis and conservation treatment left the statue in a stable condition and ready for exhibitions and future studies.

• Journal of the Mineralogical Society of Korea
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• v.13 no.4
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• pp.171-185
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• 2000

Siliceous mudstones are embedded on a large scale in the Tertiary formations of Pohang area. Some useful zeolites such as NsP, (Na, TMA)P, analcime and hydroxysodalite were synthesized from the siliceous mudstones by treating with the variety of solution, i.e ., NaOH, NaOH+NaCl, NaOH, NaOH+$NaAlO_2$and NaOH+TMAOH at the low-temperature hydrothermal system ranging 60~12$0^{\circ}C$. Major precursor of zeolites is found as opal-CT in the zeolite-forming reaction. Smectite, which is included in considerable amounts in the mudstone, appears to play a major role of Al-source in the zeolite synthesis. In comparison, chalcedonic quartz and mica are rather insoluble in alkaline solution, and thus, these are observed as major impurities in the reaction products. An addition of $NaAlO_2$to NaOH solution is effective for eliminating these impurities in the reaction procedure, through these are partly dissolved when elevating the reaction temperature, concentration, and time. Phase change from NaP to hydroxysodalite takes place at the NaOH concentrations of 3.0~4.0 M, and the reaction is not sensitive to the temperature shift. NaP is more stable at lower NaOH concentration and higher activity of $Na_{+}$ whereas analcime is sensitive to the temperature change and stable at higher than $100^{\circ}C$ and 2.0~4.0 M in NaOH concentration. For the pure NaP synthesis without any other products, the treatment of mudstones with 1:1 solution of NaOH and $NaAlO _2$ turns out to be quite effective. NaP was successfully synthesized together with analcime at $100^{\circ}C$ as well as lower concentrations of NaOH+NaCl solution. In addition, the organic type, (Na, TMA)P was formed together with smectite in the 1:1 solution of NaOH and TMAOH.

• Journal of Periodontal and Implant Science
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• v.27 no.2
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• pp.363-377
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• 1997

The main goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal diseases. Although conventional forms of periodontal therapy show sound clinical results, the healing results in long junctional epithelium. There have been numerous materials and surgical techniques developed for new attachment and bone regeneration. Bone grafts can be catagorized into: autografts, allografts, xenografts and bone substitutes. Synthetic bone substitute materials include hydroxyapatite, tricalcium phosphate, calcium carbonate, and Plaster of Paris. Calcium sulfate has found its use in dental practice for the last 30 years. Recent animal studies suggest that periodontal regeneration in 3 wall intrabony defect may be enhanced by the presence of calcium sulfate. And it is well known that 2 wall & 1 wall defect have less osteogenic potential, So we need to study the effect of calcium sulfate in 1 wall intrabony defect in dogs. The present study evaluates the effects of calcium sulfate on the epithelial migration, alveolar bone regeneration and cementum formation in intrabony defects of dogs. Four millimeter-deep one-wall intrabony defects were surgically created in the mesial aspect of anterior teeth and mesial & distal aspects of premolars. The test group received calcium sulfate grafts with a flap procedure. The control underwent flap procedure only. Histologic analysis following 8 weeks of healing revealed the following results: 1. The lengths of junctional epithelium were: 2.52mm in the control, and 1.89mm in the test group. There was no statistical significance between the two groups. 2. Alveolar bone formation were: 0.61mm in the control, and 1.88mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 3. Cementum formations were: l.lmm in the control, and 2.46mm in the test group. There was a statistically significant difference between the two groups (p<0.05). 4. The length of CT adhesion were: O.97mm in the control, and 0.17mm in the test group. There was no statistically significant differences between the two groups These results suggest that the use of calcium sulfate in intrabony defects has little effect on junctional epithelium migration, but has significant effects on new bone and new cementum formations.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5965-5972
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• 2013

PIN1 is one member of the parvulin PPIase family. By controlling Pro-directed phosphorylation, PIN1 plays an important role in cell transformation and oncogenesis. There are many polymorphisms in the PIN1 gene, including rs2233678 and rs2233679 affecting the PIN1 promoter. Recently, a number of case-control studies were conducted to investigate the association between PIN1 gene rs2233678 and rs2233679 polymorphism and cancer risk. However, published data are still conflicting. In this paper, we summarized data for 5,427 cancer cases and 5,469 controls from 9 studies and attempted to assess the susceptibility of PIN1 gene polymorphism to cancers by a synthetic meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the relationship. All analyses were performed using Stata software. Our results suggested that rs2233678 represented a protective factor in overall analysis (CC vs GG: OR= 0.697, 95%CI: 0.498-0.976; CG vs GG: OR=0.701, 95%CI: 0.572-0.858; Dominant model: OR= 0.707, 95%CI: 0.590-0.847; C allele vs G allele: OR=0.734, 95%CI: 0.623-0.867) and especially for squamous cell carcinoma of the head and neck, lung cancer and breast cancer in Asians and Caucasians. The rs2233679 polymorphism was significantly associated with decreased cancer risk in overall analysis (CT vs CC: OR=0.893, 95%CI=0.812-0.981; Dominant model: OR=0.893, 95%CI=0.816-0.976; T allele vs C allele; OR=0.947, 95%CI=0.896-1.000) and especially in Asians. In conclusion, our meta-analysis suggested that -842G>C (rs2233678) and -667C>T (rs2233679) may contribute to genetic susceptibility for cancer risks. Further prospective research with larger numbers of worldwide participants is warranted to draw comprehensive and firm conclusions.

• Computers and Concrete
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• v.32 no.3
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• pp.247-261
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• 2023

Due to the non-uniform distribution of meso-structure, the diffusion of chloride ions in concrete show the characteristics of characteristics of randomness and fuzziness, which leads to the non-uniform distribution of chloride ions and the non-uniform corrosion of steel rebar in concrete. This phenomenon is supposed as the main reason causing the uncertainty of the bearing capacity deterioration of reinforced concrete structures. In order to analyze and predict the durability of reinforced concrete structures under chloride environment, the random features of chloride ions transport in concrete were studied in this research from in situ meso-structure of concrete. Based on X-ray CT technology, the spatial distribution of coarse aggregates and pores were recognized and extracted from a cylinder concrete specimen. In considering the influence of ITZ, the in situ mesostructure of concrete specimen was reconstructed to conduct a numerical simulation on the diffusion of chloride ions in concrete, which was verified through electronic microprobe technology. Then a stochastic study was performed to investigate the distribution of chloride ions concentration in space and time. The research indicates that the influence of coarse aggregate on chloride ions diffusion is the synthetic action of tortuosity and ITZ effect. The spatial distribution of coarse aggregates and pores is the main reason leading to the non-uniform distribution of chloride ions both in spatial and time scale. The chloride ions concentration under a certain time and the time under a certain concentration both satisfy the Lognormal distribution, which are accepted by Kolmogorov-Smirnov test and Chi-square test. This research provides an efficient method for obtain mass stochastic data from limited but representative samples, which lays a solid foundation for the investigation on the service properties of reinforced concrete structures.