• Title/Summary/Keyword: Materials analysis

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Initial Evaluation using Geochemical Data to infer Tectonic Setting of Mt. Baekdu/Changbaishan Volcano (백두산 화산의 지체구조 추론을 위한 지구화학적 데이터를 이용한 기초 평가)

  • Yun, Sung-Hyo;Chang, Cheolwoo;Pan, Bo
    • Journal of the Korean earth science society
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    • v.43 no.1
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    • pp.128-139
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    • 2022
  • This study aimed to investigate the tectonic setting of the volcanic edifice at Mt. Baekdu by analyzing petrochemical characteristics of Holocene felsic volcanic rocks distributed in the Baekdusan stratovolcano edifice and summit of the Cheonji caldera rim, as well as Pleistocene mafic rocks of the Gaema lava plateau and Changbaishan shield volcano edifice. During the early eruption phases, mafic eruption materials, with composition ranging from alkali basalt to trachybasalt, or from subalkaline (tholeiitic) basalt to basaltic andesite formed the Gaema lava plateau and Changbaishan shield volcanic edifice, whereas the Baekdusan stratovolcano edifice and Holocene tephra deposits near the summit of the Cheonji caldera comprises trachytic and rhyolitic compositions. Analysis results revealed bimodal compositions with a lack of 54-62 SiO2, between the felsic and mafic volcanic rocks. This suggested that magmatic processes occurred at the locations of extensional tectonic settings in the crust. Mafic volcanic rocks were plotted in the field of within-plate volcanic zones or between within-plate alkaline and tholeiite zones on the tectonic discrimination diagram, and it was in good agreement with the results of the TAS diagram. Felsic volcanic rocks were plotted in the field of within-plate granite tectonic settings on discrimination diagrams of granitic rocks. None of the results were plotted in the field of arc islands or continental margin arcs. The primitive mantle-normalized spider diagram did not show negative (-) anomalies of Nb and Ti, which are distinctive characteristics of subduction-related volcanic rocks, but exhibited similar patterns of ocean island basalt. Trace element compositions showed no evidence of, magmatic processes related to subduction zones, indicating that the magmatic processes forming the Baekdusan volcanic field occurred in an intraplate environment. The distribution of shallow earthquakes in this region supports the results. The volcanic rocks of the Baekdusan volcanic field are interpreted as the result of intraplate volcanism originating from the upwelling of mantle material during the Cenozoic era.

Correlation Analysis between the Factors Associated with Osteoporosis and the Fat Infiltration Rate of the Multifidus and Erector Spinae Muscles in Osteoporotic Vertebral Compression Fracture Patients (골다공증성 척추 압박 골절 환자에서 다열근과 척추기립근의 지방 침투율과 골다공증 관련 인자의 상관 관계 분석)

  • Jun, Deuk Soo;Baik, Jong-Min;Choi, Ji Uk
    • Journal of the Korean Orthopaedic Association
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    • v.55 no.4
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    • pp.318-323
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    • 2020
  • Purpose: To examine the relationship between total fat infiltration (TFI) rate, which quantifies the reduction of muscles around the spine and is an important factor for sarcopenia, and the factors affecting osteoporotic vertebral compression fracture. Materials and Methods: Patients treated for osteoporotic compression fractures of the lumber spine from January 2012 to December 2016 were analyzed retrospectively. Among them, this study included ninety-eight patients who were 1) diagnosed with osteoporosis with a bone mineral density (BMD) T score of less than 2.5 g/cm2, 2) received vertebroplasty or kyphoplasty for lumbar fractures, 3) involved one segment of the lumbar spine, and 4) were followed-up for more than one year. The TFI rate confirmed by analyzing magnetic resonance imagings with the Image J program was studied. Based on this, the relationship between the TFI of the multifidus and erector spinae muscles and the factors of osteoporosis were analyzed. Results: The mean TFI of the multifidus and erector spinae was 14.66±10.16. The spine BMD showed a positive correlation with the hip BMD, but a negative correlation with the TFI. A positive correlation was observed between the hip BMD and body mass index. In addition, vitamin D was positively correlated with both the hip and spine BMD but negatively correlated with the TFI rate. Conclusion: Muscle growth helps treat osteoporosis, and can prevent fractures that occur frequently in osteoporosis patients. Increasing the vitamin intake can also slow the progression of muscle atrophy.

A Study for Kinetics and Oxidation Reaction of Alcohols using (C10H8N2H)2Cr2O7 ((C10H8N2H)2Cr2O7를 이용한 알코올들의 산화반응과 반응속도에 관한 연구)

  • Park, Young-Cho;Kim, Soo-Jong
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.927-933
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    • 2022
  • We synthesized (C10H8N2H)2Cr2O7, The structure of the product was characterized with FT-IR(infrared) and elemental analysis. The oxidation of benzyl alcohol by (C10H8N2H)2Cr2O7 in organic solvents showed that the reactivity increased with the increase of the dielectric constant. The oxidation of alcohols was examined by (C10H8N2H)2Cr2O7 in DMF, acetone. As a resuit, (C10H8N2H)2Cr2O7 was found as efficicent oxidizing agent that converted benzyl alcohol, allyl alcohol, primary alcohol and secondary alcohols to the corresponding aldehydes or ketones(65%~95%). The selective oxidation of alcohols was also examined by (C10H8N2H)2Cr2O7 in DMF, acetone. (C10H8N2H)2Cr2O7 was selective oxidizing agent(15%~95%) of benzyl alcohol, allyl alcohol and primary alcohol in the presence of secondary ones. In the presence of DMF solvent with acidic catalyst such as H2SO4. (C10H8N2H)2Cr2O7 oxidized benzyl alcohol(H) and its derivatives. The Hammett reaction constant(ρ) was -0.69(308K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.

The Trend of Cigarette Design and Tobacco Flavor System Development

  • Wu, Jimmy Z.
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.1
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    • pp.67-73
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    • 2002
  • In light of addressing consumer health concern, coping with anti-tobacco movement, and promoting new product, tobacco industry is actively pursuing to make a new generation of cigarettes with low tar and nicotine deliveries, and less harmful substances. Low tar and low nicotine cigarettes increases their market shares dramatically world wide, especially in KT&G, multinational tobacco companies, EU countries, even in China regulated by CNTC to set up yearly target to lower tar and nicotine deliveries. On the other hand, to design a new cigarette with reduced harmful substances begins to gain speed. The "modified Hoffmann list" publishes thirty plus substances in tobacco leaf and main smoke stream, which is the prime suspect causing health problems. Various ways and means are developed to reduce such components including new tobacco breeds, new curing method, tobacco leaf treatment before processing, selected filtration system, innovated casing system to reduce free radicals, as well as some non conventional cigarette products. In TSRC held this year, the main topic is related to reduce tobacco specific nitrosamines in tobacco leaf. The new generation of cigarette is in the horizon. It still needs a lot help to produce commercial products with satisfied taste and aroma characters. The flavor industry is not regulated by many governments demanding which ingredients might or might not be for tobacco use. However, most of the cigarette companies self impose a list of ingredients to guide flavor suppliers to design flavors. Unfortunately, the number of ingredients in those lists is getting shorter every year. It is understandable that the health is not the only reason. Some cigarette companies are playing safe to protect the company from potential lawsuit, while others are just copying from their competitors. Moreover, it is obvious that it needs more assistance from casings and flavors to design new generation of cigarettes with missing certain flavor components in tobacco leaf and main smoke stream. These flavor components are either non-existed or at lower level at new form of cured tobacco leaf or filtered in the main smoke stream along with reduced harmful substances. The use of carbon filters and other selected filtration system poses another tough task for flavor system design. Specific flavor components are missing from the smoke analysis data, which brings a notion of "carbon taste" and "dryness" of mouth feel. It is ever more demanded by cigarette industry to flavor suppliers to produce flavors as body enhancer, tobacco notes, salivating agents, harshness reducer, and various of aromatic notes provided they are safe to use. Another trend is that water based flavor or flavor with reduced ethanol as solvent is gaining popularity. It is preferred by some cigarette companies that the flavor is compounded with all natural ingredients or all ingredients should he GMO free. The new generation of cigarettes demands many ways of new thinking process. It is also vital for tobacco industry. It reflects the real needs for the consumers that the cigarette product should be safe to use as well as bearing the taste and aroma characters smokers always enjoyed. An effective tobacco flavor system is definitely a part of the equation. The global trend of tobacco industry is like trends of any other industries lead by consumer needs, benefited with new technology availability, affected by the global economy, and subjected for various rules and regulations. Anti-tobacco organizations and media exceptionally scrutinize cigarette, as a legal commercial product. Cigarette is probably the most studied commercial product for its composition, structure, deliveries, effects, as well as its new developmental trend. Therefore, any new trend of cigarette development would be within these boundaries. This paper is trying to point out what it would be like for tobacco industry in the next few yews and what concerns the tobacco industry. It focuses mostly on the efforts to produce safer cigarettes. It is such a vital task for the tobacco industry and its affiliate industries such as cigarette papers, filters, flavors, and other materials. The facts and knowledge presented in this paper might be well known for the public. Some of the comments and predictions are very much personal opinion for a further discussion.

Asbestos Trend in Korea from 1918 to 2027 Using Text Mining Techniques in a Big Data Environment (빅데이터환경에서 텍스트마이닝 기법을 활용한 한국의 석면 트렌드 (1918년~2027년))

  • Yul Roh;Hyeonyi Jeong;Byungno Park;Chaewon Kim;Yumi Kim;Mina Seo;Haengsoo Shin;Hyunwook Kim;Yeji Sung
    • Economic and Environmental Geology
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    • v.56 no.4
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    • pp.457-473
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    • 2023
  • Asbestos has been produced, imported and used in various industries in Korea over the past decades. Since asbestos causes fatal diseases such as malignant mesothelioma and lung cancer, the use of asbestos has been generally banned in Korea since 2009. However, there are still many asbestos-containing materials around us, and safe management is urgently needed. This study aims to examine asbestos-related trend changes using major asbestos-related keywords based on the asbestos trend analysis using big data for the past 32 years (1991 to 2022) in Korea. In addition, we reviewed both domestic trends related to the production, import, and use of asbestos before 1990 and asbestos-related policies from 2023 to 2027. From 1991 to 2000, main keywords related to asbestos were research, workers, carcinogens, and the environment because the carcinogenicity of asbestos was highlighted due to domestic production, import, and use of asbestos. From 2001 to 2010, the main keywords related to asbestos were lung cancer, litigation, carcinogens, exposure, and companies because lawsuits were initiated in the US and Japan in relation to carcinogenicity due to asbestos. From 2011 to 2020, the high ranking keywords related to asbestos were carcinogen, baseball field, school, slate, building, and abandoned asbestos mine due to the seriousness of the asbestos problem in Korea. From 2021 to present (2023), the main search keywords related to asbestos such as school, slate (asbestos cement), buildings, landscape stone, environmental impact assessment, apartment, and cement appeared.

A Randomized Phase III Study of Patients With Advanced Gastric Adenocarcinoma Without Progression After Six Cycles of XELOX (Capecitabine Plus Oxaliplatin) Followed by Capecitabine Maintenance or Clinical Observation

  • Guk Jin Lee;Hyunho Kim;Sung Shim Cho;Hyung Soon Park;Ho Jung An;In Sook Woo;Jae Ho Byun;Ji Hyung Hong;Yoon Ho Ko;Der Sheng Sun;Hye Sung Won;Jong Youl Jin;Ji Chan Park ;In-Ho Kim;Sang Young Roh;Byoung Yong Shim
    • Journal of Gastric Cancer
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    • v.23 no.2
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    • pp.315-327
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    • 2023
  • Purpose: Oxaliplatin, a component of the capecitabine plus oxaliplatin (XELOX) regimen, has a more favorable toxicity profile than cisplatin in patients with advanced gastric cancer (GC). However, oxaliplatin can induce sensory neuropathy and cumulative, dose-related toxicities. Thus, the capecitabine maintenance regimen may achieve the maximum treatment effect while reducing the cumulative neurotoxicity of oxaliplatin. This study aimed to compare the survival of patients with advanced GC between capecitabine maintenance and observation after 1st line XELOX chemotherapy. Materials and Methods: Sixty-three patients treated with six cycles of XELOX for advanced GC in six hospitals of the Catholic University of Korea were randomized 1:1 to receive capecitabine maintenance or observation. The primary endpoint was progression-free survival (PFS), analyzed using a two-sided log-rank test stratified at a 5% significance level. Results: Between 2015 and 2020, 32 and 31 patients were randomized into the maintenance and observation groups, respectively. After randomization, the median number of capecitabine maintenance cycles was 6. The PFS was significantly higher in the maintenance group than the observation group (6.3 vs. 4.1 months, P=0.010). Overall survival was not significantly different between the 2 groups (18.2 vs. 16.5 months, P=0.624). Toxicities, such as hand-foot syndrome, were reported in some maintenance group patients. Maintenance treatment was a significant factor associated with PFS in multivariate analysis (hazard ratio, 0.472; 95% confidence interval, 0.250-0.890; P=0.020). Conclusions: After 6 cycles of XELOX chemotherapy, capecitabine maintenance significantly prolonged PFS compared with observation, and toxicity was manageable. Maintenance treatment was a significant prognostic factor associated with PFS.

Marginal bone loss between internal- and external- abutment connection type implants placed in the first molar area (제1대구치 위치에 식립된 단일 임플란트의 지대주 연결 유형에 따른 임플란트 주위골 흡수)

  • Seok-Hyun Lee;Eun-Woo Lee;Ha-Na Jung;Ok-Su Kim
    • Journal of Dental Rehabilitation and Applied Science
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    • v.39 no.1
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    • pp.32-44
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    • 2023
  • Purpose: The purpose of this study was to investigate the effect of implant connection type on marginal bone loss (MBL) and to analyze the factors that affect MBL. This study focuses on single implants planted in the upper and lower first molar area. Materials and Methods: A total of 87 implants from 68 patients were tracked for a period over 5 years. There were 57 external connection type (EC) implants and 30 internal connection type (IC) implants in 38 males and 30 females. The MBL and EA were measured from intraoral radiograph images taken after 5 years at most. Results: Significant difference in MBL between EC and IC type was observed in patients without GBR or diabetes. Patients without GBR exhibited an MBL of -0.065 ± 0.859 mm in EC type and -0.627 ± 0.639 mm in IC type (P = 0.025). Using multiple regression analysis, a statistically significant negative correlation was observed between MBL and conditions including implant-abutment connection type (β = -0.303), diabetes (β = -0.113), emergence angle > 30° (β = -0.234), and age (β = -0.776). Conclusion: Within this results, IC type implants had less MBL than EC type, and implant prosthesis with emergence angle over 30° showed greater MBL. To minimize the MBL of the implant and ensure implant stability, careful consideration should be given to the EA of implant prosthesis and its connection type.

The color stability and antibacterial of provisional polyethyl methacrylate (PEMA) resin with zirconia nanoparticles (지르코니아 나노입자 첨가된 PEMA (Polyethyl Methacrylate)레진 표면의 색안정성 및 항균평가)

  • Kim, Hee-Seon;Lee, Seon-Ki;Jang, Woohyung;Park, Chan;Lim, Hyun-Pil
    • Journal of Dental Rehabilitation and Applied Science
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    • v.38 no.1
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    • pp.18-25
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    • 2022
  • Purpose: This study aimed to evaluate the color stability and antibacterial properties of the surface of polyethyl methacrylate (PEMA) resin with zirconia nanoparticles added. Materials and Methods: The control group was pure PEMA resin, and the experiment group was PEMA resin 15 mm in diameter and 2.5 mm in thickness disk-shaped specimens with 2, 4 and 8 w/v% of zirconia nanoparticles added, which were respectively divided into Group Z2, Group Z4, and Group Z8. After analyzing the surface roughness and color stability of the specimens, their antibacterial properties were evaluated using Porphyromonas gingivalis (P. gingivalis). The Statistical analysis was performed using when normality was met in the Shapiro-Wilk test, one-way ANOVA was used to test parameters, and Tukey's test was used as a post hoc test. When normality was not met, the Kruskal-Wallis test, a non-parametric test was used (P < 0.05). Results: The surface roughness measurement found that there was no significant difference between the experimental and control groups. The color stability evaluation showed that the Z2, Z4, and Z8 groups were within the color range of natural teeth. The adhesion of P. gingivalis was evaluated to be significantly reduced in Group Z2 compared to the control group (P < 0.05). In the Z2 group, Z4 group, and Z8 group, dead cells bacteria than the control group were observed. Conclusion: In conclusion, PEMA resin with zirconia nanoparticles added was within the range of natural teeth in color and reduced the adhesion of P. gingivalis.

Descriptive Study for Sonographic Morphology of the 1st Facet of Subscapularis Footprint (견갑하건 부착부의 제1부착면에 대한 초음파 소견의 기술적 연구)

  • Sohn, Hoon-Sang;Wi, Chan Kuk;Shon, Min Soo
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.4
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    • pp.343-352
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    • 2019
  • Purpose: The purpose of this study was to document the sonographic morphology of the subscapularis footprint, particularly the 1st facet, of the non-pathologic subscapularis tendon and footprint, and analyze the correlation between the size of the 1st facet and the demographic variables. Materials and Methods: Between March 2015 and December 2017, retrospectively data analysis was performed for the ultrasound (US) scans of 115 consecutive shoulder (mean age 53.4 years, range 23-74 years) with non-pathologic subscapularis tendon and footprint. The sonographic findings of the 1st facet of the subscapularis footprint was a very unique, flat, broad, and plane angle in the upward direction, which were distinguished from the other facets. On US, the transverse (medio-lateral) and longitudinal (superior-inferior) length of the 1st facet on axis of the humerus shaft were recorded. The demographic variables, including age, site, body height, weight, body mass index (BMI), and arm length, were reviewed. Results: On US, the mean transverse length of the 1st facet was 12.75 mm (range 10.54-14.50 mm, standard deviation [SD] 0.712) and the mean longitudinal length was 12.22 mm (range 9.20-13.30 mm, SD 0.888). The transverse and longitudinal length of the size of the 1st facet were significantly greater in males than in females (p<0.001, p=0.001). Of the demographic data (body height, weight, BMI, arm length) that showed a significant positive linear correlation, the correlation with body height (transverse r=0.749, p<0.001; longitudinal r=0.642, p<0.001) showed the strongest relationship, and the correlation with the BMI was weakly related. The relationships between the size of the 1st facet to site/age were not statistically significant or appeared to have no linear correlation. Conclusion: The structural and morphologic features of the 1st facet of the subscapularis footprint on the US were identified. This will provide anatomic knowledge of an US examination for subscapularis tendon pathology.

A Comparison between Minimally Invasive Percutaneous Plate Osteosynthesis and Plate Fixation in the Treatment of Clavicle Midshaft Fracture (쇄골 간부 골절의 최소 침습적 경피적 금속판 고정술과 관혈적 수술 비교)

  • Yoo, Seong-Ho;Kang, Suk-Woong;Kim, Bu-Hwan;Song, Moo-Ho;Kim, Yeong-Joon;Park, Gyu-Taek;Kwack, Chang-Hun
    • Journal of the Korean Orthopaedic Association
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    • v.52 no.1
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    • pp.1-6
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    • 2017
  • Purpose: To retrospectively compare minimally invasive percutaneous plate osteosynthesis (MIPPO) with open plate fixation for the treatment of clavicle midshaft fracture. Materials and Methods: Between November 2011 to May 2014, 40 cases that were followed for more than 1 year-among all cases of MIPPO and open plate fixation-were analyzed. The study population was divided into two groups: group A included 20 cases of MIPPO and group B included 20 open plate fixation cases. The comparative analysis between the two groups was based on the operative time, bone union, functional evaluation (American Shoulder and Elbow Society score), incision length, pain relief (visual analogue scale, VAS), and complication. Results: The bone union was successful for all the cases, and the functional evaluation scores of the shoulder joint were satisfactory for both groups (p>0.05). The operative time was 47.5 minutes and 58.7 minutes for group A and B, respectively (p<0.05). The incision length for group A was 6.2 cm and that for group B was 10.7 cm with statistical significance (p<0.05). Pain relief (VAS) after surgery for group A showed a quick recuperation in the early stages. For complications, there were 2 cases of dysesthesia and 1 case of malunion due to metal fixation failure in group A. There were 6 cases of dysesthesia and 2 cases of cosmetic problem due to hypertrophic scar in group B. Conclusion: Surgical results of clavicle shaft fracture were satisfactory for both groups, but group A had advantages of shorter operative time, minimal incision length, and better pain relief in the early stages compared with group B. However, we need further evaluations with long-term follow-up results and complications, such as malunion and exposure on radiation.