• Title/Summary/Keyword: reference background

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Development of Isotope Dilution-Liquid Chromatography/Tandem Mass Spectrometry as a Candidate Reference Method for the Determination of Acrylamide in Potato Chips

  • Park, Sun-Young;Kim, Byung-Joo;So, Hun-Young;Kim, Yeong-Joon;Kim, Jeong-Kwon
    • Bulletin of the Korean Chemical Society
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    • v.28 no.5
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    • pp.737-744
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    • 2007
  • An isotope dilution-liquid chromatography/tandem mass spectrometric method was developed as a candidate reference method for the accurate determination of acrylamide in potato chips, starch-rich foodstuff cooked at high temperature. Sample was spiked with 13C3-acrylamide and then extracted with water. The extract was further cleaned up with an Oasis HLB solid-phase extraction (SPE) cartridge and an Oasis mixed-phase cation exchange (MCX) SPE cartridge. The extract was analyzed by using LC/ESI/Tandem MS in positive ion mode. LC with a medium reversed-phase (C4) column was optimized to obtain adequate chromatographic retention and separation of acrylamide. MS was operated to selectively monitor [M+H]+ ions of the analyte and its isotope analogue at m/z 72 and m/z 75, respectively. Sample was also analyzed by the LC/MS with selectively monitoring the collisionally induced dissociation channels of m/z 72 → m/z 55 and m/z 75 → 58. Compared to the LC/MS chromatograms, the LC/MS/MS chromatograms showed substantially reduced background chemical noises coming from solvent clusters formed during ESI spray processes and interferences from sample matrix. Repeatability and reproducibility studies showed that the LC/MS/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0% while the LC/MS results are influenced by chemical interferences.

Anatomical study of the location of the antilingula, lingula, and mandibular foramen for vertical ramus osteotomy

  • Park, Jin Hoo;Jung, Hwi-Dong;Kim, Hyung Jun;Jung, Young-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.40
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    • pp.15.1-15.6
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    • 2018
  • Background: The purpose of this study was to identify the location of the antilingula, lingula, and mandibular foramen in Korean cadavers and to promote safe and accurate surgery without damage to the inferior alveolar neurovascular bundle (IANB) when performing a vertical ramus osteotomy (VRO). Methods: This study was conducted on the dried mandibles of 20 adult cadavers. Digital calipers were used to measure the distances from the anatomical reference points (antilingula, lingula, and mandibular foramen). Result: The antilingula was located at the anterior 44% and superior 31% in the ramus. The lingula was located at the anterior 55% and superior 30% in the ramus. The mandibular foramen was located at the anterior 58% and superior 46% in the ramus. Regarding the positional relationship with the antilingula, the lingula was located 0.54 mm superior and 4.19 mm posterior, and the mandibular foramen was located 6.95 mm inferior and 4.98 mm posterior. The results suggested that in order to prevent damage to the IANB, osteotomy should be performed in the posterior region of ramus at least 29% of the total horizontal length of the ramus. Conclusion: Using only the antilingula as a reference point is not guaranteed to IANB injury. However, it is still important as a helpful reference point for the surgeon in the surgical field.

Consolidation of FRBR Family Models Focusing on FRBR Library Reference Model ('FRBR family' 모형의 통합에 관한 연구 - FRBR 도서관 참조모형을 중심으로 -)

  • Park, Zi-young
    • Journal of the Korean Society for Library and Information Science
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    • v.50 no.1
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    • pp.533-553
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    • 2016
  • FRBR family models, which is published from 1998 to 2010, will be restructured in 2016 and the new name of the model is "FRBR Library Reference Model (LRM)." FRBR LRM is a consolidated model based on the legacy FRBR family of conceptual models - FRBR, FRAD, FRSAD and the two ontological models - FRBRCore and FaBio, as well as FRBRoo, the cooperated model with museum field. In this study, therefore, FRBR LRM is analyzed in respect to background information, characteristics of the model, such as user tasks, entities, attributes, and relationships. Experimental adaptation to $prot{\acute{e}}g{\acute{e}}$ for the LRM's entities and relationships is also conducted. Through this test, the differences between the original models and the consolidated model was reviewed and the applicability of the FRBR LRM model to the semantic web is also discussed. From now on, we have to select and modify among the various FRBR related models to meet our information needs. It will be difficult to find only one Implementation Methodology for every information needs.

Changes of Pulmonary Disability Grades according to the Spirometry Reference Equations (폐기능 예측식에 따른 폐환기능 장해도 변화)

  • Lee, Joung-Oh;Choi, Byung-Soon
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.2
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    • pp.108-114
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    • 2010
  • Background: The aim was to estimate the differences between pulmonary disability grades according to the spirometry reference equations (the Korean equation and the Morris equation). Methods: Spirometry was performed on 16,916 male and 1,353 female special examination for pneumoconiosis, in the period of 2007~2009. Changes in predictive values for forced expiratory volume in one second ($FEV_1$), forced vital capacity (FVC) and $FEV_1$/FVC and in disability grade were evaluated using both equations. Results: Mean FVCs for men and women were 4,218.7 mL and 2,801.5 mL in predictive values after the application of the Korean equation, and 3,763.9 mL and 2,395.6 mL after the Morris equation, respectively. Compared with the Morris equation, the Korean equation showed 10.8% and 14.5% of excesses for men and women (p<0.001). Mean $FEV_1s$ for men and women were 3,102.5 mL and 2,107.1 mL in the Korean equation, and 2,667.8 mL and 1,699.6 mL in the Morris equation, respectively. Compared with the Morris equation, the Korean equation showed 14.0% and 19.3% of excesses for men and women (p<0.001). Men and women who showed the changes of disability grades using the Korean equation in place of the Morris equation were 23.9% (4,052/16,916) and 22.9% (311/1,353) on FVC, and 23.1% (3,913/16,916) and 10.7% (145/1,353) on $FEV_1$. Conclusion: Applying different reference equations for spirometry has resulted in changes for disability grades in special examination for pneumoconiosis.

The Study on Knowledge Management Methodology Through the Reference Services, the Core of the Special Libraries (전문도서관 기반의 지식경영 방법론 연구 - 특히 참고 정보봉사를 중심으로 -)

  • Roh, Jeong-Ran
    • Journal of the Korean Society for Library and Information Science
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    • v.37 no.2
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    • pp.343-364
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    • 2003
  • The importance of Knowledge Management (KM) can be easily recognized in many diverse aspects of the theory studies and in KM's efforts to help implement the government's policy to innovate corporation management. The core of KM is to improve the circulation of knowledge by generation, accumulation, sharing, utilization and acquisition by learning. The improvement of knowledge circulation would result in high quality and quantity of intellectual assets in corporations and make decision-making more efficient. This, too, is the operational philosophy of the special libraries. The primary objective of this study is to promote KM by presenting KM methodology and by explaining a theoretical background and cases, based on the existing special libraries. I cite an example of a case wherein merging intellectual assets and human resources activated the company culture. The reference service system, which is the core of the special library, was used in this merging.

Validation of dietary reference intake equations for estimating energy requirements in Korean adults by using the doubly labeled water method

  • Kim, Eun-Kyung;Kim, Jae-Hee;Kim, Myung-Hee;Ndahimana, Didace;Yean, Seo-Eun;Yoon, Jin-Sook;Kim, Jung-Hyun;Park, Jonghoon;Ishikawa-Takata, Kazuko
    • Nutrition Research and Practice
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    • v.11 no.4
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    • pp.300-306
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    • 2017
  • BACKGROUND/OBJECTIVES: The doubly labeled water (DLW) method is considered the gold standard for the measurement of total energy expenditure (TEE), which serves to estimate energy requirements. This study evaluated the accuracy of predictive dietary reference intake (DRI) equations for determining the estimated energy requirements (EER) of Korean adults by using the DLW as a reference method. SUBJECTS/METHODS: Seventy-one participants (35 men and 36 women) aged between 20 and 49 years were included in the study. The subjects' EER, calculated by using the DRI equation ($EER_{DRI}$), was compared with their TEE measured by the DLW method ($TEE_{DLW}$). RESULTS: The DRI equations for EER underestimated TEE by -36.3 kcal/day (-1.3%) in men and -104.5 kcal/day (-4.9%) in women. The percentages of accurate predictions among subjects were 77.1% in men and 62.9% in women. There was a strong linear correlation between $EER_{DRI}$ and $TEE_{DLW}$ (r = 0.783, P < 0.001 in men and r = 0.810, P < 0.001 in women). CONCLUSIONS: The present study supports the use of DRI prediction equations to determine EER in Korean adults. More studies are needed to confirm our results and to assess the validity of these equations in other population groups, including children, adolescents, and older adults.

Bridging Research and Extension Gaps of Paddy Yield in Andhra Pradesh, India

  • Kumar, K. Nirmal Ravi
    • Agribusiness and Information Management
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    • v.10 no.1
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    • pp.1-15
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    • 2018
  • Many paddy cultivating farmers in the country are forced to use their limited resources to produce adequate food for their family, leading to the degradation and reduction in potential of these resources. The yield levels of paddy at the farmers' level and in the Front Line Demonstrations (FLDs) conducted in the farmers' fields is not at par with potential yield of the paddy variety. The gap between potential yield of crop variety and yield realized in FLDs refers to Research gap and the yield gap between FLDs and due to farmers' practice refers to Extension gap. The earlier studies conducted in India in general and in Andhra Pradesh in particular highlighted the existence of both research and extension gaps with reference to paddy. It is essential that, the narrowing of both research and extension gaps is not static, but dynamic considering the influence of technological interventions in boosting paddy yields at FLDs level and at farmers' level and also with the improvement of the yield potential of paddy varieties. This calls for integrated and holistic approaches to address these two gaps and with this background, the researcher aimed at this in depth study. The findings revealed that, research gaps are high with reference to weed management and pest management and extension gaps are high with reference to farm mechanization followed by fertilizer management. Reliable source of seed, capital use and frequency of meetings with Scientists or Agricultural Officers significantly influence the extension gaps in paddy. Farmers also prioritized socio-economic and technical constraints and the analysis infers that, it is high time now for the farmers to adopt the planned technological interventions on scientific scale to minimize the extension gaps to the extent possible. As the enabling environment in the State of Andhra Pradesh is highly encouraging for the farmers with relevant policy instruments in the form of subsidized inputs, free power, credit at concessional rates of interest, constructing irrigation projects etc., the adoption of the proposed technological interventions significantly contribute to minimizing both research and extension gaps in paddy cultivation in Kurnool district of Andhra Pradesh.

Plan-Class Specific Reference Quality Assurance for Volumetric Modulated Arc Therapy

  • Rahman, Mohammad Mahfujur;Kim, Chan Hyeong;Kim, Seonghoon
    • Journal of Radiation Protection and Research
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    • v.44 no.1
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    • pp.32-42
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    • 2019
  • Background: There have been much efforts to develop the proper and realistic machine Quality Assurance (QA) reflecting on real Volumetric Modulated Arc Therapy (VMAT) plan. In this work we propose and test a special VMAT plan of plan-class specific (pcsr) QA, as a machine QA so that it might be a good solution to supplement weak point of present machine QA to make it more realistic for VMAT treatment. Materials and Methods: We divided human body into 5 treatment sites: brain, head and neck, chest, abdomen, and pelvis. One plan for each treatment site was selected from real VMAT cases and contours were mapped into the computational human phantom where the same plan as real VMAT plan was created and called plan-class specific reference (pcsr) QA plan. We delivered this pcsr QA plan on a daily basis over the full research period and tracked how much MLC movement and dosimetric error occurred in regular delivery. Several real patients under treatments were also tracked to test the usefulness of pcsr QA through comparisons between them. We used dynalog file viewer (DFV) and Dynalog file to analyze position and speed of individual MLC leaf. The gamma pass rate from portal dosimetry for different gamma criteria was analyzed to evaluate analyze dosimetric accuracy. Results and Discussion: The maxRMS of MLC position error for all plans were all within the tolerance limit of < 0.35 cm and the positional variation of maxPEs for both pcsr and real plans were observed very stable over the research session. Daily variations of maxRMS of MLC speed error and gamma pass rate for real VMAT plans were observed very comparable to those in their pcsr plans in good acceptable fluctuation. Conclusion: We believe that the newly proposed pcsr QA would be useful and helpful to predict the mid-term quality of real VMAT treatment delivery.

Occupational Exposure to Metals in Shooting Ranges: A Biomonitoring Study

  • Vandebroek, Eline;Haufroid, Vincent;Smolders, Erik;Hons, Luc;Nemery, Benoit
    • Safety and Health at Work
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    • v.10 no.1
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    • pp.87-94
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    • 2019
  • Background: Lead (Pb) exposure in shooting ranges has been reduced by various measures such as jacketed ammunition and lead-free primers. Nevertheless, this may lead to exposure to other metals, potentially resulting in adverse health effects. Methods: In a cross-sectional study, 35 subjects from seven different shooting ranges were studied: four shooting instructors, 10 police officers, 15 Special Forces, and six maintenance staff members. Metals and metalloids were determined in blood and urine by inductively coupled plasma-mass spectrometry. Results: The concentrations of most elements did not differ significantly between groups or compared to reference values, except for Sb and Pt in urine and Pb in blood. Mean values for Sb were considerably higher in urine from the Special Forces ($0.34{\mu}g/L$), the maintenance staff ($0.13{\mu}g/L$), and shooting instructors ($0.32{\mu}g/L$) compared to the police officers before shooting ($0.06{\mu}g/L$) and a Belgian reference value ($0.04{\mu}g/L$). For Pt, the Special Forces showed higher mean urinary concentrations ($0.078{\mu}g/L$) compared to a Belgian reference value (<$0.061{\mu}g/L$). Mean values for blood lead were markedly higher in the Special Forces ($3.9{\mu}g/dL$), maintenance staff ($5.7{\mu}g/dL$), and instructors ($11.7{\mu}g/dL$) compared to police officers ($1.4{\mu}g/dL$). One instructor exceeded the biological exposure index for blood Pb ($38.8{\mu}g/dL$). Conclusion: Since both Pb and Sb were found to be higher in shooting range employees, especially among frequent shooters, it is advisable to provide appropriate protective equipment, education, and medical follow-up for shooting range personnel in addition to careful choice of ammunition.

Development of a Screw-Crane System for Pre-Lifting the Sternal Depression in Pectus Excavatum Repair: A Test of Mechanical Properties for the Feasibility of a New Concept

  • Park, Hyung Joo;Rim, Gongmin
    • Journal of Chest Surgery
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    • v.54 no.3
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    • pp.186-190
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    • 2021
  • Background: Pre-lifting of the sternum marked a major turning point in pectus excavatum repair. The author developed the crane technique in 2002 and successfully applied it to more than 2,000 cases using sternal wire stitching. However, blind sternal suturing limited the use of the wire-stitch crane. We propose a novel screw for sternal lifting as a new tool for the crane technique. Methods: We developed a screw system strong enough to withstand the pressure needed for sternum lifting. The screw was designed to have a broader thread to hold the bony tissue securely. The screw's sustaining power was tested using the torsion, driving torque, and axial pull-out tests in a polyurethane block and ex-vivo porcine sternum. Results: The screws were easily driven into the sternum, and the head of the screw was connectable to the table-mounted retractor. In the torsion test, the 2° offset torsional yield was 4.53 N·m (reference value, 1 N·m). In the polyurethane block driving torque test, the maximum torque was 0.98 N·m (reference value, 0.70 N·m). The axial pull-out test was 446 N (reference value, 100 N). The maximum pull-out resistance in the ex-vivo porcine sternum model was 1,516 N. Conclusion: The screw crane was strong enough to sustain the chest wall weight to be lifted. Thus, the screws could effectively replace the sternal wire stitching in crane pre-lifting of the sternum. We expect that application of the screw-crane will be easy and that it will improve the safety and success rate of pectus repair surgery.