• 제목/요약/키워드: Center of Mass(C.M)

검색결과 320건 처리시간 0.028초

Optimization of Enzyme Digestion Conditions for Quantification of Glycated Hemoglobin Using Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry

  • Jeong, Ji-Seon
    • Mass Spectrometry Letters
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    • 제5권2호
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    • pp.52-56
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    • 2014
  • Glycated hemoglobin (HbA1c) is used as an index of mean glycemia over prolonged periods. This study describes an optimization of enzyme digestion conditions for quantification of non-glycated hemoglobin (HbA0) and HbA1c as diagnostic markers of diabetes mellitus. Both HbA0 and HbA1c were quantitatively determined followed by enzyme digestion using isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with synthesized N-terminal hexapeptides as standards and synthesized isotope labeled hexapeptides as internal standards. Prior to quantification, each peptide was additionally quantified by amino acid composition analysis using ID-LC-MS/MS via acid hydrolysis. Each parameter was considered strictly as a means to improve digestion efficiency and repeatability. Digestion of hemoglobin was optimized when using 100 mM ammonium acetate (pH 4.2) and a Glu-C-to-HbA1c ratio of 1:50 at $37^{\circ}C$ for 20 h. Quantification was satisfactorily reproducible with a 2.6% relative standard deviation. These conditions were recommended for a primary reference method of HbA1c quantification and for the certification of HbA1c reference material.

Determination of 5-HT2C agonist KKHQ80114 and KKHQ80109 in Rat Plasma and Urine by Gas-Chromatography/Mass Spectrometry

  • Im, Hye-Yeon;Park, Hye-Sil;Choo, Hyun-Ah;Pae, Ae-Nim;Kwon, Oh-Seung
    • Journal of Pharmaceutical Investigation
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    • 제39권5호
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    • pp.321-325
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    • 2009
  • 5-HT$_{2C}$ receptors have been considered as therapeutic targets for the treatment of various central nervous system disorders such as depression, anxiety, epilepsy, schizophrenia and sleep disorders. We chemically synthesized KKHQ80114 (K14) and KKHQ80109 (K09), selective 5-HT$_{2C}$ agonists, with the purpose of developing therapeutic agents for the treatment of obesity. The objective of this work is to investigate analytical methods of these compounds in the plasma and urine of rats by gas chromatography/mass spectrometry. In this experiment, K14 was determined in plasma and urine by using K09 as internal standard. Calibration curves give a good linearity in plasma (r$^2$=0.9993) and urine (r$^2$=0.9988). Among hexane, ethyl acetate and diethyl ether, the highest peak was observed in diethyl ether. However, ethyl acetate was used since more interfering peaks were observed with diethyl ether. Inter-day precision and accuracy were determined in the ranges of 50-500 ng/mL for plasma and 10-500 ng/ml for urine. Quantitation limits were 50 ng/mL plasma and 25 ng/ mL urine. These data may be applicable for further studies of these compounds including absorption and metabolism due to no pharmacokinetic or analytical data available.

The Relation of Body Mass Index to Dietary Intake and Blood Lipid Levels in Korean Adults

  • Jean, Rim;Kim, Chin-Ock;Kang, Soon-Ah;Wee, Hio-Jung
    • Nutritional Sciences
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    • 제1권1호
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    • pp.70-76
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    • 1998
  • This study was designed to investigate the relationship between body mass index (BMI) and dietary intake, and the relationship between BMI and plasma lipid levels in Korean adults. This study was conducted from January 1 to December 31 of 1997. It consisted of 3781 subjects (men 2402, women : 1379) with the majority between the ages of 40 and 59. The dietary assessment was based upon a twenty-four-hour food record. Subjects were classified into one of four reference BMI groups : underweight ($\leq 20 kg/m^2$), normal (20.1-25.0 kg/$m^2$), overweight (25.1-30.0 kg/$m^2$), and obese (>30 kg/$m^2$). The biochemical assessment included measurements of plasma total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), triglyceride (TG), lipoprotein (a), and plasminogen activator inhibitor-1 (PAI-1). The BMI study showed that 60.5% of the men measured were normal and 32.6% of the men were overweight and/or obese subjects. Sixty-four percent of the women were normal and 20.3% of the women measured were overweight and/o. obese subjects. With respect to the daily energy intake of the men and women subjects, the levels of daily energy intake appeared to increase as values of BMI increased. Men of the overweight group had significantly higher protein, fat and cholesterol intake than those of the normal or the underweight groups. The alcohol intake of the men in the overweight group was also significantly higher than that of the men in the underweight group. With respect to percent energy intake of macronutrients, there was no significant difference between the four BMI groups and percent energy intake for all the subjects in the study. The ratio of percent energy intake of carbohydrates : protein : fat : alcohol of the normal women group was 62 : 17 : 20 : 1, respectively. Women apparently had a higher intake of carbohydrates than men (52 : 17 : 19 : 10). With respect to the levels of plasma TC, LDL-C, TG, and HDL-C, the levels of plasma TC, LDL-C and TC appeared to increase as the values of BMI increased, while the level of HDL-C appeared to decrease as values of BMI increased. Levels of lipoprotein (a) appeared to be inversely related to the values of BMI, and levels of PAI-1 appeared to increase as values of BMI increased. The results of this study demonstrate that there is a relationship between dietary intake and BMI, and that there is a relationship between BMI and blood lipids levels.

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골프 퍼팅 시 오류동작 교정을 위한 진단과 처방 (The Diagnosis and Prescription for Correcting Errors of Putting in Golf Skill : A Case Study)

  • 하종규
    • 한국운동역학회지
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    • 제16권2호
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    • pp.21-24
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    • 2006
  • The purpose of this paper is to diagnose the errors by comparing putting motion with the single pendulum pattern applicable to putting in golf skill and order prescription that correct errors of putting. In the modern-day game of golf, putting remains the key to shooting low scores, and the ability to hole putts can turn a good round into a great round A semi-golfer, subject(sex female, age 20yrs, mass 94.3kg, height 1.65m) who has troubles to do putting is chosen. Six cameras, ProReflex MCU240(240Hz) made by Qualisys company is used to capture putting motion and data is processed by QTM(Qualisys Track Manager) and Mathematica 5.0. The result that differentiates the putting and the single pendulum pattern is acquired To make the pattern of subject's putting to the single pendulum pattern quasi-equal, one tries to lower center of mass gradually. As a result of it, one has a similar pattern like the single pendulum Conclusively, to lower C.O.M one orders prescriptions that increase the weight and length of a putter and lower C.O.M subject's segment. Further improvements to the study could be to train a subject according to prescriptions and to monitor putting again. It will probably be necessary to simulate putting motions and to research relations for body shapes and putting patterns in order to establish suitable putting-motions.

Characteristics of Trypsin-like Protease and Metalloprotease Associated with Mycelium Differentiation of Streptomyces albidoflavus SMF301

  • Kang, Sung-Gyun;Kim, In-Seop;Jeong, Byung-Cheol;Ryu, Jae-Gon;Rho, Yong-Taik;Lee, Kye-Joon
    • Journal of Microbiology
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    • 제33권4호
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    • pp.307-314
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    • 1995
  • Trypsin like protease (TLP) and metalloprotease (MTP) were induced in associated with the mycelium differentiation in Streptomyces albidoflavus SMF301. TLP and MTP were purified and characterized from the culture. The molecular mass of TLP and MTP were estimated to be 32 kDa and 18 kDa, respectively. The molecular mass of TLP and MTP were estimated to be 32 kDa and 18 kDa, respectively. The optimum pH and temperature of TLP were 10 and 40.$^{\circ}C$ Those of MTP were 8 and 55 $^{\circ}C$ TLP was stable at alkaline pH (6-9) and unstable above 45.$^{\circ}C$and MTP was stable at alkaline pH and unstable above 80.$^{\circ}C$ Km and Vmax values with benzoyl-arginyl p-nitroanilide of TLP were 139 $\mu$M, and 10 nmole of nitroanilide released per min per$\mu\textrm{g}$ protein, respectively. Km, and Vmax values with a synthetic substrate, leucine p-nitroanilide, or MTP were 58.9 $\mu$M, 3.47 nmol of nitroanilide released per min per$\mu\textrm{g}$protein, respectively. TLP was inhibited competitively by leupeptin; the inhibition constant was 0.0031 $\mu$M. MTP was inhibited by EDTA, phenonthroline and bestatin.

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Purification and Characterization of Protein Phosphatase 2C from Rat Liver

  • Oh, Joung-Sook;Hwang, In-Seong;Choi, Myung-Un
    • BMB Reports
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    • 제30권3호
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    • pp.222-228
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    • 1997
  • Protein phosphatase 2C (PP2C) is one of the four major serine/threonine phosphatases which is dependent on $Mg^{2+}$ for its activity. PP2C was purified from rat liver cytosol and its characteristics were investigated. The substrate employed for routine assay was $[^{32}P]casein$ phosphorylated by PKA. The purification process involved DEAE chromatography, ammonium sulfate fractionation, phenyl sepharose chromatography, sephacryl 5-200 gel filtration, and histone agarose chromatography. The SDS-PAGE of PP2C showed one major single protein band at a position corresponding to a molecular mass of 43 kd and the purification fold was 637. The enzyme showed a pH optimum of 8 and $K_M$ value was $1.9\;{\mu}M$. However, when the substrate was changed to $[^{32}P]histone$, the pH optimum was shifted to 7 and $K_M$ value was $2.3\;{\mu}M.\;Mg^{2+}$ was essential to the enzyme activity and okadaic acid did not exert any inhibitory effect on the enzyme. To examine residue in the active site of PP2C effects of some protein-modifying reagents were tested.

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CNC M/C을 활용한 목제문화상품디자인개발 연구 (A study on design development for wooden cultural products by using CNC M/C)

  • 곽우섭
    • 한국가구학회지
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    • 제12권2호
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    • pp.51-59
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    • 2001
  • Opening 21th Century, all the Countries of the world has been focusing on build up the foundation of cultural infrastructure in a various way, since the awareness of importance for cultural design products has been turnover. On the other hand, our cultural crafts' industry has not escaped from poor working environment and lagging behind conventional product system, and yet there is no complete system for mass production. The study is collaboration with Tourism Industry Innovation Center in Kwangju University for development of cultural products of wooden crafts by using cultural resources in Kwangju area and CNC M/C which is up-to-date digital technology. It aims to make possibility of mass production and discrimination on design for wooden crafts which is based on highly skilled technical manpower and creativities, and expects to develop and merchandise global wooden cultural products.

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A Simple and Sensitive High Performance Liquid Chromatography-Electrospray Ionization/Mass Spectrometry Method for the Quantification of Ethyl Pyruvate in Rat Plasma

  • Kim, Hyun-Ji;Kim, Seung-Woo;Lee, Ja-Kyeong;Yoon, Sung-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제32권4호
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    • pp.1221-1227
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    • 2011
  • Ethyl pyruvate (EP) is known as a scavenger of reactive oxygen species (ROS) in the body through its role in the donation of diketone groups to metals to form an EP-metal complex. In order to develop a method for the quantification of EP in biological media, a sensitive and specific, high-performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI/MS) method is used to determine the EP-alkali metal ion binding species. The analyte was separated on a ZORBOX SB-C8 ($3.5{\mu}m$, $30mm{\times}2.1mm$ I.D.) column and analyzed in selected ion monitoring (SIM) mode with a positive ESI interface using the m/z 255 $[2M + Na]^+$ ion. The method was validated over the concentration range of $0.5-60.0\;{\mu}g$/mL under 1/9 (v/v) of acetonitrile/methanol solvent system with flow rate 0.05 mL/min. The limit of quantification (LOQ) was $0.5{\mu}g$/mL.

Ginsenoside Rg5 promotes muscle regeneration via p38MAPK and Akt/mTOR signaling

  • Ryuni Kim;Jee Won Kim;Hyerim Choi;Ji-Eun Oh;Tae Hyun Kim;Ga-Yeon Go;Sang-Jin Lee;Gyu-Un Bae
    • Journal of Ginseng Research
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    • 제47권6호
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    • pp.726-734
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    • 2023
  • Background: Skeletal muscles play a key role in physical activity and energy metabolism. The loss of skeletal muscle mass can cause problems related to metabolism and physical activity. Studies are being conducted to prevent such diseases by increasing the mass and regeneration capacity of muscles. Ginsenoside Rg5 has been reported to exhibit a broad range of pharmacological activities. However, studies on the effects of Rg5 on muscle differentiation and growth are scarce. Methods: To investigate the effects of Rg5 on myogenesis, C2C12 myoblasts were induced to differentiate with Rg5, followed by immunoblotting, immunostaining, and qRT-PCR for myogenic markers and promyogenic signaling (p38MAPK). Immunoprecipitation confirmed that Rg5 increased the interaction between MyoD and E2A via p38MAPK. To investigate the effects of Rg5 on prevention of muscle mass loss, C2C12 myotubes were treated with dexamethasone to induce muscle atrophy. Immunoblotting, immunostaining, and qRT-PCR were performed for myogenic markers, Akt/mTOR signaling for protein synthesis, and atrophy-related genes (Atrogin-1 and MuRF1). Results: Rg5 promoted C2C12 myoblast differentiation through phosphorylation of p38MAPK and MyoD/E2A heterodimerization. Furthermore, Rg5 stimulated C2C12 myotube hypertrophy via phosphorylation of Akt/mTOR. Phosphorylation of Akt induces FoxO3a phosphorylation, which reduces the expression of Atrogin-1 and MuRF1. Conclusion: This study provides an understanding of how Rg5 promotes myogenesis and hypertrophy and prevents dexamethasone-induced muscle atrophy. The study is the first, to the best of our knowledge, to show that Rg5 promotes muscle regeneration and to suggest that Rg5 can be used for therapeutic intervention of muscle weakness and atrophy, including cancer cachexia.