• Food Science of Animal Resources
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• 제33권5호
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• pp.617-625
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• 2013

The present study was carried out to assess dietary exposure and risk for the infant population by lead (Pb), cadmium (Cd), and arsenic (As) exposure through modified milk powder and formulas. Analysis of heavy metals was performed using a microwave device and inductively coupled plasma-mass spectrometry, the method for which was fully validated. Various samples (n=204), including modified milk powder, modified milk, follow-up modified milk powder, infant formula and follow- up formula, were collected from retail outlets and markets across Korea. The mean contents of heavy metals were Pb 0.0004 (modified milk)-0.010 (infant formula) mg/kg, Cd 0.002 (modified milk)-0.007 (follow-up formula) mg/kg, and As 0.004(modified milk)-0.040 (infant formula) mg/kg, respectively. For risk assessment, daily intakes of heavy metals through maximum intake of modified milk powder and formulas were calculated and compared with reference doses established by JECFA and WHO. The dietary exposures of heavy metals were $0.78-1.04{\mu}g$ Pb/d, $0.65-0.87{\mu}g$ Cd/d, and $2.25-3.00{\mu}g$ As/d, corresponding to 2.0-4.5%, 7.1-16.0%, and 0.4-0.9% of reference doses, respectively. Therefore, the level of overall dietary exposure to heavy metals for Korean infant through food intake was below 20% of the reference dose, indicating a low risk to infant consumers.

• Journal of the Korean Home Economics Association
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• 제34권4호
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• pp.249-263
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• 1996

According to the design method for constructing the G gori(the traditional Korean jacket)collar, there are differences in form after its completion. In the construction design of the midsection of the gusset as in that of the basic G gori, not only was the positioning of the two sides of the collar not smooth, but also, when the collar strip was attached, there would be an imbalance on one side or the other so that it was difficult to achieve symetry. Therefore in this project, by applying the pattern design of the gusset midsection to that of the collar midsection, not only did attaching the collar and the collar strip create a visual effect by equalizing the lengths of the tow sides, but the construction was also easy. This method of construction introduces the three-dimensional aspect of the human form in its conic, spherical and cylindrical aspects, so that, through schematizing the scientific character of Korea's clothing, its appropriateness is verified. As a matter of fact, since th-ere in no standardization of pattern whether for educational use or for mass-produced clothing, so that even the patterns used in computer-assisted design are executed according to the designer's personal skill, the reality is that after completion of construction the quality has not been uniform. For this schematization, inverse calculation of measurements pertaining to the calculation formula and of teaching materials has been referenced. In particular, the partial requlation of the calculation formula pertaining to the basic pattern construction, the method of making the collar midsection, and the construction method of the extreme and mean ratio adjustment can be adjusted for all measurements, thereby providing the establishment of a design criterion and the possibility of the standardization of construction methods. The production method for the pattern design is as follows: 1) The conic angle for the G gori's girth, length and neck width is fixed at 70 degrees. 2) The radius of the cone is B/2. 3) The calculation formula is B/4 + 1.5cm 4) The armhole formula is B/4, the same as in the basic method. 5) The width formula is B/10. 6) The ratio of the collar junction(width of collar + width of collar strip)to the gusset length is 5:8. 7) The length of the side seam is a length intersecting the armhole line and the conic radius (B/2), that is an arc that exceeds the length of the G gori's midsection; the component ratio of this length to the collar junction is accordingly 13:5. 8) The curve frame length of the back midsection is an arc exceeding B/4(the armhole line). 9) The ratio of the sleeve opening calculation formula to the armhole length is 8:5, forming an arc with the midsection length.

• Mass Spectrometry Letters
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• 제5권1호
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• pp.24-29
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• 2014

An advanced and reliable high performance liquid chromatography (HPLC)/ultraviolet detector (UV)/ion-trap time-of-flight (IT-TOF) mass spectrometry was developed for the simultaneous quantification of 19 marker compounds in Bang-poong-tong-sung-san (BPTS), a traditional oriental prescription. Various parameters affecting HPLC separation and IT-TOF detection were investigated, and optimized conditions were identified. The separation was achieved on a Capcell PAK C18 column ($1.5mm{\times}250mm$, $5{\mu}m$ particle size) using a gradient elution of acetonitrile and water containing 0.1% formic acid at a flow rate of 0.1 mL/min. The column temperature was maintained at $40^{\circ}C$ and the injection volume was $2{\mu}L$. IT-TOF system was equipped with an electrospray ion source (ESI) operating in positive or negative ion mode. The optimized electrospray ionization parameters were as follows: ion spray voltage, +4.5 kV (positive ion mode), or -3.5 kV (negative ion mode); drying gas ($N_2$), 1.5 L/min; heat block temperature, $200^{\circ}C$. Automatic $MS^n$ (n = 1~3) analyses were carried out to obtain structural information of analytes. Elemental compositions and their mass errors were calculated based on their accurate masses obtained from a formula predictor software. The marker compounds in BPTS were identified by comparisons between $MS^n$ spectra from standards and those from extracts. Moreover, the libraries of $MS^2$ and $MS^3$ spectra and accurate masses of parent and fragment ions for marker compounds were constructed. The developed method was successfully applied to the BPTS extracts and identified 17 out of 19 marker compounds in the BPTS extracts.

• Journal of the Korea institute for structural maintenance and inspection
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• 제28권2호
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• pp.9-16
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• 2024

In this paper, we aimed to convert the fire curve in volume units to a fire curve per unit area for application in the Fire Dynamic Simulator (FDS) surface heat release rate method. The fire curve was expressed dimensionlessly considering the total combustion characteristic time, and improvements were made to represent the appropriate ratios for the growth , steady, and decay phases concerning the fire intensity. Additionally, a correction function for combustion characteristic time varying with mass increase was derived. Also to control the growth time values according to the increase in mass, a function to correct the growth phase ratio was derived. Consequently, utilizing existing data, a formula was established to determine the reference mass for combustion materials and predict the fire curve based on mass increase.

• Herbal Formula Science
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• 제21권1호
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• pp.177-185
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• 2013

Objectives : Leejung-tang (Lizhong-tang) has been used for treatment of gastrointestinal disorders in Korea. In this study, we performed quantification analysis of five marker components, liquiritin, ginsenoside Rb1, ginsenoside Rg1, glycyrrhizin, and 6-gingerol in Leejung-tang using a ultra performance liquid chromatography- electrospray ionization-mass spectrometer (UPLC-ESI-MS). In addition, we evaluated antioxidant activity of Leejung- tang. Methods : The column for separation of five constituents used a UPLC BEH C18 ($100{\times}2.1mm$, $1.7{\mu}m$) maintained at $45^{\circ}C$. The mobile phase consisted of two solvent systems, 0.1% (v/v) formic acid in H2O (A) and CH3CN (B) by gradient flow. The flow rate was 0.3 mL/min with detection at mass spectrometer. The antioxidative activities conduct an experiment on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of Leejung-tang. Results : Calibration curves of five marker compounds were acquired with r2 values > 0.99. The amount of the five compounds in Leejung-tang were 0.07 - 0.84 mg/g. The concentration required for 50% reduction (RC50) against ABTS radical was 119.02 ug/mL. In addition, the scavenging against DPPH radical of Leejung-tang was 11.4%, 14.5%, 19.8%, 29.6%, and 49.2% at 25 ug/mL, $50{\mu}g/mL$, $100{\mu}g/mL$, $200{\mu}g/mL$, and $400{\mu}g/mL$, respectively. Conclusions : The established LC-MS/MS method will be helpful to improve quality control of Leejung-tang. In addition, Leejung-tang is a potential antioxidant therapeutic agent.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3139-3144
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• 2010

A model system has been established for the evaluation of the uncertainty of the value from measurements of multiple subsamples by isotope dilution mass spectrometry (IDMS). In this report, we apply this model system for the evaluation of measurement uncertainty in determination of folic acid in infant formula. Five subsamples were analyzed by IDMS. The mean of the measurement results of the five subsamples was assigned as the final measurement value. The standard deviation (s) of the results from five subsamples was attributable to repeatability of the measurement. The uncertainty components in the IDMS measurement methods were categorized into two groups. Group I includes uncertainty components which give common systematic effects to all subsamples and do not contribute to the variation among multiple measurements (repeatability). Group II includes uncertainty components that give random effects on the measurement results, and are related with the measurement repeatability. These random effects are attributed to s. Therefore, the uncertainty of the final value was calculated by combining the standard deviation of the mean of multiple measurements, $s/{\surd}n$ (where n = 5), and the measurement uncertainty associated with the uncertainty components that give systematic effects.

• Korean Journal of Pharmacognosy
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• 제45권2호
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• pp.113-120
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• 2014

Generally, Gwakhyangjeonggi-san has been used for treatment of diarrhea-predominant irritable bowel syndrome. In this study, an ultra-performance liquid chromatography-electrospray ionization-mass spectrometer method was established for the simultaneous quantification of marker compounds 1-20 in Gwakhyangjeonggi-san water extract. All analytes were separated by gradient elution using two mobile phases on a UPLC BEH $C_{18}$ ($100{\times}2.1mm$, $1.7{\mu}m$) column and maintained at $45^{\circ}C$. The injection volume was $2.0{\mu}L$ and the flow rate was 0.3 mL/min with detection at mass spectrometer. Regression equations of the compounds 1-20 were acquired with $r^2$ values ${\geq}0.9950$. The values of limit of detection and quantification of all analytes were 0.01-2.79 ng/mL and 0.03-8.37 ng/mL, respectively. The amounts of the compounds 1-20 in Gwakhyangjeonggi-san water extract were not detected $-3,236.67{\mu}g/g$. The established LC-MS/MS methods will be valuable to improve quality control of traditional herbal formula, Gwakhyangjeonggi-san.

• Structural Engineering and Mechanics
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• 제11권4호
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• pp.357-372
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• 2001

In this paper, cantilevered tall structures are treated as cantilever bars with varying cross-section for the analysis of their free longitudinal (or axial) vibrations. Using appropriate transformations, exact analytical solutions to determine the longitudinal natural frequencies and mode shapes for a one step non-uniform bar are derived by selecting suitable expressions, such as exponential functions, for the distributions of mass and axial stiffness. The frequency equation of a multi-step bar is established using the approach that combines the transfer matrix procedure or the recurrence formula and the closed-form solutions of one step bars, leading to a single frequency equation for any number of steps. The Ritz method is also applied to determine the natural frequencies and mode shapes in the vertical direction for cantilevered tall structures with variably distributed stiffness and mass. The formulae proposed in this paper are simple and convenient for engineering applications. Numerical example shows that the fundamental longitudinal natural frequency and mode shape of a 27-storey building determined by the proposed methods are in good agreement with the corresponding measured data. It is also shown that the selected expressions are suitable for describing the distributions of axial stiffness and mass of typical tall buildings.

• Herbal Formula Science
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• 제22권2호
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• pp.63-76
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• 2014

Objectives : This study investigated the improvement effects of Pakistani (DF-a) and Chinese Ephedra herba-containing Gangjihwan (DF-b) on obesity in a high fat diet-fed obese mouse model. Methods : Eight-week-old C57BL/6N mice were divided into four groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and DF-a and DF-b groups given a high fat diet with DF-a (80 mg/kg), and DF-b (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, feeding efficiency ratio, blood lipid markers, fat weight and histology were examined. Results : 1. Body weight gain and fat mass were significantly decreased in DF-a and DF-b groups compared with control. The extent of decreases was eminent in DF-a group. 2. Feeding efficiency ratio and circulating leptin concentration were significantly decreased in DF-a and DF-b groups compared with control, whereas circulating adiponectin concentration was increased in DF-a and DF-b groups compared with control. 3. Consistent with their effects on body weight gain and fat mass, circulating concentrations of triglyceride, glucose and insulin were decreased in DF-a and DF-b groups compared with control. 4. The size of adipocytes were decreased by DF-a and DF-b compared with control, whereas the adipocyte number per unit area was increased by them, suggesting that DF-a and DF-b decreased the number of large adipocytes. 5. Consistent with their effects on body weight gain, liver fibrosis was reduced in DF-a and DF-b groups compared with control. Conclusions : In conclusion, these results suggest that DF-a and DF-b not only decrease feeding efficiency ratio, plasma leptin concentration, and blood anti-obesity biomarkers, but also reduce fat mass, contributing to the improvement of obesity. DF-a and DF-b also inhibit liver fibrosis. In addition, these effects were similar between Pakistani Ephedra herba and Chinese Ephedra herba-containing Gangjihwan.

• Herbal Formula Science
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• 제17권1호
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• pp.85-98
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• 2009

In the oriental medicine, the Persicae Semen is a useful material for promoting blood circulation through removement of the extravasated blood in a blood vessel. This study is based on Dongueibogam, which has been widely used for herbal clinic in Korea. And this study is investigated to make sure of the range of Persicae Semen treatment, the nature of disease, the pathology and the dosage of it in Dongueibogam. The following conclusions were reached through investigations on the main prescriptions that used in Dongueibogam as a key ingredient. 1. The prescriptions of blending with the Persicae Semen are utilized in 25 fields of treatments such as feces, uterus, blood diseases, etc. 2. The Persicae Semen is used in the treatment of constipation, removement of blood stasis of gynecology. 3. The average mass of the Persicae Semen is 0.352g, the standard limited range of adding the Persicae Semen to medical prescription is 0.5$\sim$40g or 6$\sim$40pieces per dose. But, in most case of treatment medicines, an typical and regular adding dose is the range of 2$\sim$4g. 4. The Persicae Semen is one of basic materials for a fundamental prescription among several herbal remedies for the pathology.