• Mass Spectrometry Letters
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• v.2 no.1
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• pp.1-7
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• 2011

China's rapid economic growth has resulted in significant environmental side effects. Therefore, China has been interested in reducing her dependence on foreign oil and gas by developing technologies needed for hydrogen, in addition to her increasing energy mix of nuclear and renewable energy form, such as solar and wind power. There are three isotopes of hydrogen, i.e. protium (P or H), deuterium (D), and tritium (T). Both deuterium and tritium are important materials in nuclear fuel cycle industry. Tritium is one of the critical radioactive nuclides. Planning for and implementing contamination control as a part of normal operation and maintenance activities is an important function in any hydrogen facility, especially tritium facility. The development of hydrogen isotopes analysis is the key issues in this area. Mass spectrometry (MS) with medium (about 600) and high resolution (> 1,400) is commercially available; however, the routine analysis of hydrogen isotopes is done with low-resolution MS (< 200) in China. This paper summarizes the progress of MS measurement technology for hydrogen isotope abundance in China, focusing on our lab's research program and technical status. An analyzing method has been introduced for accurate measurement of tritium abundance in the H.D.T system by low resolution MAT-253 MS. The quotient of compression ratio coefficient is determined by building up equipment for laboratory-scale preparation of secondary standard gases and by considering the difference in sensitivity between hydrogen isotopes. The results show that the measured value is reproducible within the relative error range of 0.8% for gas samples of different tritium abundance.

• Journal of The Korean Association For Science Education
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• v.24 no.1
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• pp.29-47
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• 2004

Two project-centered secondary school programs were studied as part of an effort to elucidate successful components for science reform-based curriculum development. The Teachers for Exciting Science (TES), and Foundational Approaches in Science Teaching (FAST) programs in Korea and U.S., respectively, are project-centered programs because their curricula are centered on the activities initiated and engaged in by the students. Students serve as principal investigators in their projects, and teachers serve as guides. Both programs were analyzed based on criteria such as curriculum design, teaching, lives of students, lives of teachers, evaluation of program, from the Third International Mathematics and Science Study (TIMSS). In the programs, teachers and students directed the development of curricula and their implementation. Students assumed teacher roles as mentors of other students. And emphasis was on development of communication skills through student-delivered talks and written papers, and professional development of teachers as educators and scientists. Participation in TES stimulated secondary school student interest in science, encouraged inquiry thinking, increased achievement in learning science, and promoted better awareness of science related to real life. FAST students practice laboratory and field techniques, experimental design, hypothesis formation, generalization, and practical implications of research as academic and applied disciplinarians. These project-centered programs have been successfully implemented in field, lab, and classroom curricula for secondary science education. Comparison of these programs will provide an opportunity for identifying key elements instrumental in successful implementation of guidelines for science education, as measured through successful outcomes.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.99-99
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• 2011

A statistical study of coronal hole merging and splitting has been performed through Solar Cycle 23. The NOAA/SESC solar synoptic maps are examined to identify inarguably clear events of coronal hole merging and splitting. The numbers of merging events and splitting events are more or less comparable regardless of the phase in the solar cycle. The number of both events, however, definitely shows the phase dependence in the solar cycle. It apparently has a minimum at the solar minimum whereas its maximum is located in the declining phase of the sunspot activity, about a year after the second peak in Solar Cycle 23. There are more events of merging and splitting in the descending phase than in the ascending phase. Interestingly, no event is found at the local minimum between the two peaks of the sunspot activity. This trend can be compared with the variation of the average magnetic field strength and the radial field component in the solar wind through the solar cycle. In Ulysses observations, both of these quantities have a minimum at the solar minimum while their maximum is located in the descending phase, a while after the second peak of the sunspot activity. At the local minimum between the two peaks in the solar cycle, the field strength and the radial component both have a shallow local minimum or an inflection point. At the moment, the physical reason for these resembling tendencies is difficult to understand with existing theories. Seeing that merging and splitting of coronal holes are possible by passage of opposite polarity magnetic structures, we may suggest that the energizing activities in the solar surface such as motions of flux tubes are not exactly in phase with sunspot generation, but are more active some time after the sunspot maximum.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.8
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• pp.1252-1258
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• 2018

Objective: This study was carried out to determine the effects of cumin essential oil on the silage fermentation, aerobic stability and in vitro digestibility of alfalfa silages. Methods: Alfalfa was harvested at early bloom (5th cutting) stage in October and wilted for about 3 hours. The research was carried out at three groups which were the control group where no additive control was done (CON), cumin essential oil (CMN3) with 300 mg/kg and CMN5 with 500 mg/kg cumin essential oil addition. Alfalfa was ensiled in plastic bags. The packages were stored at $8^{\circ}C{\pm}2^{\circ}C$ under laboratory conditions. All groups were sampled for physical, chemical and microbiological analysis 120th day after ensiling. At the end of the ensiling period, all silages were subjected to an aerobic stability test for 7 days. In addition, enzimatic solubility of organic matter (ESOM), metabolizable energy (ME), and relative feed value (RFV) of these silages were determined. Results: pH level decreased in the cumin groups compared to CON (p<0.05), thus inhibiting proteolytic enzymes from breaking down proteins into ammonia. In addition, it increased ESOM amount, and concordantly provided an increase of ME contents. Similarly, dry matter intake and RFV ratio increased. After opening the silage, it kept its aerobic stability for three days. Conclusion: Cumin essential oil improved fermentation, and affected chemical and microbiological characteristics of silages. Especially the addition of 300 mg/kg cumin provided cell wall fractionation through stimulating the activities of enzymes responsible. It also increased the number and activity of lactic acid bacteria (LAB) through providing a development of LAB.

• Safety and Health at Work
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• v.9 no.2
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• pp.164-171
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• 2018

Background: In recent years, the interest in health and safety in the workplace has increased. Agriculture is one of the human work activities with the highest risk indexes. Studies on risk perception of agricultural workers are often referred to as specific risk factors (especially pesticides), but the risk perception plays an important role in preventing every kind of accident and occupational disease. Methods: The aim of this research is to test a new method for understanding the relation between risk perception among farmers and the main risk factors to which they are exposed. A secondary aim is to investigate the influence of training in risk perception in agriculture. The data collection was realized using a questionnaire designed to investigate the risk perception; the questionnaire was given to a sample of 119 agricultural workers in central Italy. Through the use of the "principal components analysis" it was possible to highlight and verify the latent dimensions underlying the collected data in comparison with scales of attitudes. Results: Results show that the highest percentage of strong negative attitude is among the people who have worked for more years, while farmers who have worked for fewer years have a marked positive attitude. Conclusion: The analysis of the questionnaires through the synthetic index method (Rizzi index) showed that agricultural workers involved, in particular the elderly workers, have a negative attitude towards safety; workers are hostile to safety measures if they have not attended special training courses.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.561-571
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• 2002

The action mechanisms of several chemopreventive agents derived from herbal medicine and edible plants have become attractive issues in cancer research. Tea is the most widely consumed beverage worldwide. Recently, the cancer chemopreventive actions of tea have been intensively investigated. It have been demonstrated that the active principles of tea were attributed to their tea polyphenols. Recently, tremendous progress has been made in elucidating the molecular mechanisms of cancer chemoprevention by tea and tea polyphenols. The suppression of various tumor biomarkers including growth factor receptor tyrosine kinases, cytokine receptor kinases, P13K, phosphatases, ras, raf, MAPK cascades, NㆍFB, IㆍB kinase, PKA, PKB, PKC, c-jun, c-fos, c-myc, cdks, cyclins, and related transducing proteins by tea polyphenols has been studied in our laboratory and others. The IㆍB kinase (IKK) activity in LPS-activated murine macrophages (RAW 264.7 cells) was found to be inhibited by various tea polyphenols including (-) epigallocatechin-3-gallate (EGCG), theaflavin (TF-1), theaflavin-3-gal-late (TF-2) and theaflavin-3,3'-digallate (TF-3). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other tea polyphenols. TF-3 inhibited both IKK1 and IKK2 activity and prevented the degradation of IㆍBㆍand IㆍBㆍin activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 and other tea polyphenols could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. TF-3 and other tea polyphenols blocked phosphorylation of IB from the cytosolic fraction, inhibited NFB activity and inhibited increases in inducible nitric oxide synthase levels in activated macrophage. TF-3 and other tea polyphenols also inhibited strongly the activities of xanthine oxidase, cyclooxygenase, EGF-receptor tyrosine kinase and protein kinase C. These results suggest that TF-3 and other tea polyphenols may exert their cancer chemoprevention through suppressing tumor promotion and inflammation by blocking signal transduction. The mechanisms of this inhibition may be due to the blockade of the mitogenic and differentiating signals through modulating EGFR function, MAPK cascades, NFkB activation as wll as c-myc, c-jun and c-fos expression.

• Journal of Digital Convergence
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• v.14 no.1
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• pp.353-361
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• 2016

This study was to demonstrate the anti-inflammation effect using extracts derived from fusion-fermentation to add the function of Araliae Continentalis Radix (fACR). Since there are limitations to the use of ACR, available strains were selected through fermentation using lactobacillus strains, and the increases in total amount of polyphenols and amino acids was confirmed through comparison with Hot Water Extract of ACR. To determine the anti-inflammatory effect of the fACR was measure cytokine inflammation associated with arthritis, the arthritis when cartilage destruction is accompanied mainly MMP-9 activity was confirmed to evaluate the inhibition effect. These results show that fermentation using lactobacillus increases major biological activities and inflammatory response-restraining effects of ACR. This study is expected to be a basis for studying the preventive effect of fACR on arthritis.

• Journal of Ginseng Research
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• v.44 no.4
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• pp.655-663
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• 2020

Background: Korean Red Ginseng is known to exhibit immune-enhancing and anti-inflammatory properties. The immune-enhancing effects of the nonsaponin fraction (NSF) of Korean Red Ginseng have been studied in many reports. However, the gastroprotective effect of this fraction is not fully understood. In this study, we demonstrate the activities of NSF for gastrointestinal protection and its related critical factor. Methods: The in vitro and in vivo regulatory functions of NSF on cyclooxygenase-1 (COX-1) messenger RNA and protein levels were examined by reverse transcription polymerase chain reaction and immunoblotting analyses. Gastroprotective effects of NSF were investigated by histological score, gastric juice pH, and myeloperoxidase activity on indomethacin-induced, cold stress-induced, and acetylsalicylic acid-induced gastritis and dextran sulfate sodium-induced colitis in in vivo mouse models. Results: NSF did not show cytotoxicity, and it increased COX-1 messenger RNA expression and protein levels in RAW264.7 cells. This upregulation was also observed in colitis and gastritis in vivo models. In addition, NSF treatment in mice ameliorated the symptoms of gastrointestinal inflammation, including histological score, colon length, gastric juice pH, gastric wall thickness, and myeloperoxidase activity. Conclusion: These results suggest that NSF has gastroprotective effects on gastritis and colitis in in vivo mouse models through COX-1 upregulation.

• Nuclear Engineering and Technology
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• v.41 no.4
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• pp.455-476
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• 2009

The history of nuclear fusion research in Korea is rather short compared to that of advanced countries. However, since the mid-1990s, at which time the construction of KSTAR was about to commence, fusion research in Korea has been actively carried out in a wide range of areas, from basic plasma physics to fusion reactor design. The flourishing of fusion research partly owes to the fact that industrial technologies in Korea including those related to the nuclear field have been fully matured, with their quality being highly ranked in the world. Successive pivotal programs such as KSTAR and ITER have provided diverse opportunities to address new scientific and technological problems in fusion as well as to draw young researchers into related fields. The frame of the Korean nuclear fusion program is now changing from a small laboratory scale to a large national agenda. Coordinated strategies from different views and a holistic approach are necessary in order to achieve optimal efficiency and effectiveness. Upon this background, the present paper reflects upon the road taken to arrive at this point and looks ahead at the coming future in nuclear fusion research activities in Korea.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.1-7
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• 2017

Parkinson's disease (PD) is an irreversible neurological disorder with related locomotor dysfunction and is characterized by the selective loss of nigral neurons. PD can be experimentally induced by 6-hydroxydopamine (6-OHDA). It has been reported that reactive oxygen species, which deplete endogenous glutathione (GSH) levels, may play important roles in the dopaminergic cell death characteristic of PD. Fucoidan, a sulfated algal polysaccharide, exhibits anti-inflammatory and anti-oxidant actions. In this study, we investigated whether fucoidan can protect against 6-OHDA-mediated cytotoxicity in SH-SY5Y cells. Cytotoxicity was evaluated by using MTT and LDH assays. Fucoidan alleviated cell damage evoked by 6-OHDA dose-dependently. Fucoidan reduced the number of apoptotic nuclei and the extent of annexin-V-associated apoptosis, as revealed by DAPI staining and flow cytometry. Elevation of lipid peroxidation and caspase-3/7 activities induced by 6-OHDA was attenuated by fucoidan, which also protected against cytotoxicity evoked by buthionine-sulfoximine-mediated GSH depletion. Reduction in the glutathione/glutathione disulfide ratio induced by 6-OHDA was reversed by fucoidan, which also inhibited 6-OHDA-induced disruption of mitochondrial membrane potential. The results indicate that fucoidan may have protective action against 6-OHDA-mediated neurotoxicity by modulating oxidative injury and apoptosis through GSH depletion.