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Changes of Vitamin C Level , Lipid Peroxidation and Lipid Concentration in Plasma of Smokers and Non-smokers (흡연이 혈장의 비타민 C 함량과 지질과산화 및 지질의 농도 변화에 미치는 영향)

  • 윤군애
    • Journal of Nutrition and Health
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    • v.30 no.10
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    • pp.1180-1187
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    • 1997
  • Cigarette smoking is a major risk factor of atherosclerosis and has been reported to contain an abundance of free radical species which could be expected to deplete antioxidants such as vitamin C . The present study was designed to investigate the relationship between smoking, plasma lipid and lipoprotein concentration, and plasma vitamin C level. Fifty-five healthy male smokers and 32 non-smokers were investigated in the study. Mean age, body weight , BMI and blood pressure made no differences in both smokers and non-smokers. Significantly, smokers has higher plasma total cholesterol and LDL-C , and lower HDL-C /LDL-C ratio compared with non-smokers. Plasma level of thiobartiturin acid reactive substances(TBARS), indicator of lipid peroxidation and increased susceptibility of LDL towards lipid perosidation, were elevated in smokers(p<0.001), while the plasma vitamin C level of smokers was significantly lower than that of non-smokers(p<0.05), indicating that elevated lipid peroxidation are associated with decreased plasma vitamin C content. In non-smokers a significantly positive correlation was observed between dietary vitamin C intake and plasma levels, but no such association observed in smokers. Lack of such a relationship and the decreased plasma vitamin C level in the smokers suggest that smoking may cause increased turnover of the plasma antioxidant. Consuquently, the sustained free radical load derived from smoking causes an imbalance in oxidant/antioxidant status and it could be expected that cigarette smoking renders plasma LDL more susceptible to oxidative modification . In the present study the possible explanations for that cigarette smokers have a higher risk of cardiovascular disease include the changes of blood lipid and lipoprotein concentration, and plasma vitamin C status which might have protective functions against free radicals -medaited lipid peroxidation.

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The characteristics of soprano students' voice related to the vocal methods (발성방법에 따른 소프라노 성악도의 음성 특성)

  • Kim, Jungtaek;Seong, Cheoljae
    • Phonetics and Speech Sciences
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    • v.9 no.3
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    • pp.75-83
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    • 2017
  • The purpose of this study is to find clues to the risk of voice disorders in soprano students. The subjects of the study were 17 soprano students and 18 general students (women). The phonation of vowels /a/, /i/, and /u/ with C4 and F4 notes in each group were recorded. Then, only soprano students were made to record their classical vocalization containing vibrato. Formant, formant energy, bandwidth, VAI (vowel area index), VSA (vowel space area) and L/H ratio were analyzed. There was significant difference in F3 such that the singers' note was measured around 3 kHz which seems to be 400 Hz higher than one from general students. But, There was no significant difference in L/H ratio between soprano student and the general student. There was a significant difference in F3 in the comparison of the soprano students' two vocalization methods. Classical vocalization was measured at 200Hz higher than sustained phonation in F3. Vocal tract adjustment was made and vowel space changed, but there was no significant difference in F3 energy, which is the index of singers' formant according to the phonation method. The L/H ratio, which can be a direct indicator of vocal effort, has no difference in phonation method and is lowered in all phonation methods as the pitch increases. C4 and F4 pitches are lower than the singing range of the soprano. When the pitch changes, vocal effort increases like a general student which will be an indicator of the risk of vocalization. This will be a clue to the vocalization of the immature soprano student.

Financial Burden of Cancer Drug Treatment in Lebanon

  • Elias, Fadia;Khuri, Fadlo R;Adib, Salim M;Karam, Rita;Harb, Hilda;Awar, May;Zalloua, Pierre;Ammar, Walid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3173-3177
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    • 2016
  • Background: The Ministry of Public Health (MOPH) in Lebanon provides cancer drugs free of charge for uninsured patients who account for more than half the total case-load. Other categories of cancer care are subsidized under more stringent eligibility criteria. MOPH's large database offers an excellent opportunity to analyze the cost of cancer treatment in Lebanon. Materials and Methods: Using utilization and spending data accumulated at MOPH during 2008-2013, the cost to the public budget of cancer drugs was assessed per case and per drug type. Results: The average annual cost of cancer drugs was 6,475$ per patient. Total cancer drug costs were highest for breast cancer, followed by chronic myeloid leukemia (CML), colorectal cancer, lung cancer, and Non-Hodgkin's lymphoma (NHL), which together represented 74% of total MOPH cancer drug expenditure. The annual average cancer drug cost per case was highest for CML ($31,037), followed by NHL ($11,566). Trastuzumab represented 26% and Imatinib 15% of total MOPH cancer drug expenditure over six years. Conclusions: Sustained increase in cancer drug cost threatens the sustainability of MOPH coverage, so crucial for socially vulnerable citizens. To enhance the bargaining position with pharmaceutical firms for drug cost containment in a small market like Lebanon, drug price comparisons with neighboring countries which have already obtained lower prices may succeed in lowering drug costs.

Strength of Stainless Steel Pin-reinforced Composite Single-lap Joints (금속 핀으로 보강된 복합재 단일겹침 체결부의 강도 연구)

  • Lee, Byeong-Hee;Park, Yong-Bin;Kweon, Jin-Hwe;Choi, Jin-Ho;Choi, Ik-Hyeon;Chang, Sung-Tae
    • Composites Research
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    • v.25 no.3
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    • pp.65-69
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    • 2012
  • The main objective of this study is to investigate the effect of metal z-pinning on the failure behavior of cocured composite single-lap joints. Three different pin diameters (0.3, 0.5, and 0.7 mm) and three pin areal densities (0.5, 2.0, and 4.0%) were examined. The specimens were fabricated by T700-12K-31E#2510 unidirectional prepreg from Toray. Stainless steel pins were used for z-pinning. Test results showed that except one case with extremely low pin density of 0.5%, all other z-pinned joints exhibited lower initial crack stresses than those of the unpinned joint. However the ultimate strength of the z-pinned joint increased up to 45% at most. Furthermore, even after the complete failure of the joint, the z-pins sustained the carried load to a certain degree experiencing large deformation and provided the stable fracture behavior for the composite joint.

An Experimental Study on the Long-Term Deflection of Concrete Beams with GFRP Rebars (FRP 보강 콘크리트 보의 장기처짐에 관한 실험연구)

  • Park, Ji-Sum;You, Young-Jun;Park, Young-Hwan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.325-328
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    • 2008
  • This study is to investigate experimentally the long-term deflection of concrete beams with glass fiber reinforced polymer (GFRP) reinforcing bars subjected to the sustained flexural load for periods of up to 6 months. A total of four beams were tested. All beams were designed with net span of 2,700 mm and rectangular cross-section of 200 mm width and 300 mm depth. From the test results the time-dependent deflection of concrete beams with GFRP bars was about 40 to 70% of the initial deflection. As well as this paper compares the long-term deflection calculated by 440.1R-06 design guide and that of tested beams. The comparison indicated that the calculated long-term deflection overestimate the observed long-term deflection of concrete beams with FRP rebars.

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Evaluation for mechanical properties of high strength concrete by stressed test and stressed residual strength test - part 2 strain properties - (설계하중 사전재하 및 잔존강도 시험방법에 따른 고강도콘크리트의 고온특성 평가 - 제2보 변형특성을 중심으로 -)

  • Kim, Young-Sun;Lee, Tae-Gyu;Lee, Dae-Hui;Lee, Seung-Hoon;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.761-764
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    • 2008
  • The present study is aimed to study the effect of elevated temperatures ranging from 20 to $700^{\circ}C$ on the strain properties of high-strength concrete of 40, 60, 80MPa grade. In this study, the types of test were the stressed test and stressed residual test that the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating and when target temperature is reached, the specimens are loaded to failure. Or specimens are loaded to failure after 24hour cooling time. tests were conducted at various temperatures ($20{\sim}700^{\circ}C$) for concretes made with W/B ratios 46%, 32% and 25%. Test results showed that the relative values of elastic modulus decreased with increasing compressive strength grade of specimen and the axial strain at peak stress were influenced by the load before heating. thermal strain of concrete at high temperature was affected by the preload as well as the compressive strength.

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Microstructure and Mechanical Properties of Amorphous Matrix Composite Reinforced with Tungsten Porous Foam (텅스텐 다공성폼 강화 Zr계 비정질 기지 복합재료의 미세조직과 기계적 성질)

  • Son, Chang-Young;Lee, Sang-Bok;Lee, Sang-Kwan;Kim, Choongnyun Paul;Lee, Sunghak
    • Korean Journal of Metals and Materials
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    • v.48 no.2
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    • pp.109-115
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    • 2010
  • In the present study, a Zr-based amorphous alloy matrix composite reinforced with tungsten porous foam was fabricated without pores or defects by liquid pressing process, and its microstructures and mechanical properties were investigated. About 69 vol.% of tungsten foam was homogeneously distributed inside the amorphous matrix, although the matrix of the composite contained a small amount of crystalline phases. The compressive test results indicate that the composite was not fractured at one time after reaching the maximum compressive strength, but showed considerable plastic strain as the compressive load was sustained by tungsten foam. The tungsten foam greatly improved the strength (2764 MPa) and ductility (39.4%) of the composite by homogeneously dispersing the stress applied to the matrix. This was because the tungsten foam and matrix were simultaneously deformed without showing anisotropic deformation due to the excellent bonding of tungsten/matrix interfaces. These findings suggest that the liquid pressing process is useful for the development of amorphous matrix composites with improved strength and ductility.

Evaluation for Mechanical Properties of High Strength Concrete at High Temperature by Stressed Test and Unstressed Test (설계하중 사전재하 및 비재하방식에 의한 고강도콘크리트의 고온특성 평가)

  • Kim, Gyu-Yong;Kim, Young-Sun;Lee, Tae-Gyu;Park, Chan-Kyu;Lee, Seung-Hoon
    • Journal of the Korea Concrete Institute
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    • v.20 no.5
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    • pp.583-592
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    • 2008
  • Recently, the effects of high temperature on compressive strength, elastic modulus and strain at peak stress of high strength concrete were experimentally investigated. The present study is aimed to study the effect of elevated temperatures ranging from 20 to 700 on the material mechanical properties of high strength concrete of 40, 60, 80 MPa grade. In this study, the types of test were the stressed test and stressed residual test that the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating and when target temperature is reached, the specimens are loaded to failure. And another specimens are loaded to failure after 24 hour cooling time. Tests were conducted at various temperatures ($20{\sim}700^{\circ}C$) for concretes made with W/B ratios 46%, 32% and 25%. Test results showed that the relative values of compressive strength and elastic modulus decreased with increasing compressive strength grade of specimen and the axial strain at peak stress were influenced by the load before heating. Thermal strain of concrete at high temperature was affected by the preload level as well as the compressive strength. Finally, model equation for compressive strength and elastic modulus of heated high strength concrete proposed by result of this study.

Creep Behavior of Pultruded Ribbed GFRP Rebar and GFRP Reinforced Concrete Member (인발성형된 이형 GFRP 보강근과 GFRP 보강 콘크리트 부재의 크리프 거동)

  • You, Young-Jun;Park, Young-Hwan;Kim, Hyung-Yeol;Choi, Jin-Won;Kim, Jang-Ho Jay
    • Journal of the Korea Concrete Institute
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    • v.25 no.2
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    • pp.187-194
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    • 2013
  • Fiber reinforced polymer (FRP) has been gathering interest from designers and engineers for its possible usage as a replacement reinforcement of a steel reinforcing bar due to its advantageous characteristics such as high tensile strength, non-corrosive material, etc. Since it is manufactured with various contents ratios, fiber types, and shapes without any general specification, test results for concrete members reinforced with these FRP reinforcing bars could not be systematically used. Moreover, since investigations for FRP reinforced members have mainly focused on short-term behavior, the purpose of this study is to evaluate long-term behaviors of glass FRP (GFRP) reinforcing bar and concrete beams reinforced with GFRP. In this paper, test results of tensile and bond performance of GFRP reinforcing bar and creep behavior are presented. In the creep tests, results showed that 100 years of service time can be secured when sustained load level is below 55% of tensile strength of GFRP reinforcing bar. A modification factor of 0.73 used to calculate long-term deflection of GFRP reinforced beams was acquired from the creep tests for GFRP reinforced concrete beams. It is expected that these test results would give more useful information for design of FRP reinforced members.

The Effects of Coordinated Upper-limb Postures of Back, Shoulder, and Elbow Flexion Angles on the Subjective Discomfort Rating, Heart Rate, and Muscle Activities

  • Kong, Yong-Ku;Lee, Soo-Jin;Lee, Kyung-Suk;Seo, Min-Tae
    • Journal of the Ergonomics Society of Korea
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    • v.30 no.6
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    • pp.695-703
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    • 2011
  • Objective: This study was to investigate the effects of coordinated upper-limb body postures on the subjective discomfort rating, heart rate, and muscle activities. Background: Although generally many checklists such as OWAS, RULA, and REBA were applied to evaluate various body postures, the body postures were might be overestimated or underestimated because each body part(i.e., back, shoulder, and elbow etc.) was evaluated separately, and then added all rates of individual body parts to assess an overall risk level for the body posture in these methodologies. Methods: A total of 20 participants maintained 14 postures which were combinations of back, shoulder, and elbow flexion angles and then muscle activities, subjective discomfort, and heart rates were collected every three minute during a sustained 15 minute and 0.5kg weight holding task. Four muscle groups were investigated: erector spine, anterior deltoid, upper trapezius, triceps brachii. Results: Results showed that subjective discomfort was the lowest when the angle of back and shoulder were both $0^{\circ}s$, while the body posture with $45^{\circ}$ of back angle and $45^{\circ}$ shoulder angle was rated as the most subjective discomfort posture. In general, the subjective discomfort ratings increased as back and shoulder flexion angles increased. It was noted that, however, the subjective discomfort of body posture with a $45^{\circ}$ back angle and $45^{\circ}$ shoulder flexion angle was lower than that of body posture with a $0^{\circ}$ back and $45^{\circ}$ shoulder flexion angle. The research findings of heart rates and muscle activities showed similar results for the analyses of subjective discomfort ratings. Conclusions: The possible limitations of the current ergonomics evaluation techniques which assessing a body posture with summing all body part score after individually analyzed in this study. Based on the analyses of subjective discomfort, heart rate, and muscle activities, it was recommended that a use of effects of coordinated upper-limb body postures would be considered when one evaluates work-load for various working postures. Application: These findings can be used for developing a more accurate assessment checklist for working posture as well as preventing musculoskeletal disorders of workers in workplaces.