• Natural Product Sciences
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• v.19 no.1
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• pp.28-35
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• 2013

In this study, quantitative and pattern recognition analysis for the quality evaluation of Cinnamomi Ramulus and Cinnamomi Cortex using HPLC/UV was developed. For quantitative analysis, three major bioactive compounds were determined. The separation conditions employed for HPLC/UV were optimized using an ODS $C_{18}$ column ($250{\times}4.6$ mm, 5 ${\mu}m$) with gradient conditions of acetonitrile and water as the mobile phase, at a flow rate of 1.0 mL/min and a detection wavelength of 265 nm. This method was fully validated with respect to linearity, accuracy, precision, recovery, and robustness. The HPLC/UV method was applied successfully to the quantification of three major compounds in the extract of Cinnamomi Ramulus and Cinnamomi Cortex. The HPLC analytical method for pattern recognition analysis was validated by repeated analysis of thirty eight Cinnamomi Ramulus and thirty five Cinnamomi Cortex samples. The results indicate that the established HPLC/UV method is suitable for quantitative analysis.

• Natural Product Sciences
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• v.24 no.1
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• pp.36-39
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• 2018

Phytochemical analysis of Boehmeria nivea (Bn) leaves by medium pressure liquid chromatography led to the isolation of a flavonoid glycoside identified by spectroscopic analysis as rutin. The amount of rutin in the leaves of Bn harvested from nine regions in South Korea (Bn 1-9) which were collected on the months of June, July, August, and September was determined by HPLC-UV analysis. A gradient elution program that utilizes a $Discovery^{(R)}$ C18 ($4.6{\times}250mm$, $5{\mu}m$) column and mobile phase composed of 1% acetic acid-water: acetonitrile (90:10 to 60:40 for min) was followed. The injection volume and flow rate were $10{\mu}l$ and 1 mL/ min, respectively. UV detection was set at 350 nm. Results show that Bn-8 harvested in September reported the highest content of rutin among the samples analyzed. This study provides a basis for the optimal harvest time of Bn which maximizes the yield of rutin.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.1-10
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• 1999

Cancer cells are known to show increased rates of glycolysis metabolism. Based on this, PET studies using F-18-fluorodeoxyglucose have been used for the detection of primary and metastatic tumors. To account for this increased glucose uptake, a variety of mechanisms has been proposed. Glucose influx across the cell membrane is mediated by a family of structurally related proteins known as glucose transporters (Gluts). Among 6 isoforms of Gluts, Glut-1 and/or Glut-3 have been reported to show increased expression in various tumors. Increased level of Glut mRNA transcription is supposed to be the basic mechanism of Glut overexpression at the protein level. Some oncogens such as src or ras intensely stimulate Glut-1 by means of increased Glut-1 mRNA levels. Hexokinase activity is another important factor in glucose uptake in cancer cells. Especially hexokinase type II is considered to be involved in glycolysis of cancer cells. Much of the hexokinase of tumor cells is bound to outer membrane of mitochondria by the porin, a hexokinase receptor. Through this interaction, hexokinase may gain preferred access to ATP synthesized via oxidative phosphorylation in the inner mitochondria compartment. Other biologic factors such as tumor blood flow, blood volume, hypoxia, and infiltrating cells in tumor tissue are involved. Relative hypoxia may activate the anaerobic glycotytic pathway. Surrounding macrophages and newly formed granulation tissue in tumor showed greater glucose uptake than did viable cancer cells. To expand the application of FDG PET in oncology, it is important for nuclear medicine physicians to understand the related mechanisms of glucose uptake in cancer tissue.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.3
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• pp.117-124
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• 1992

Waves around a practical hull form and a series 60 model are computed by rectangular variable spacing and staggered flesh systems based on MAC(Marker and Cell) method. As a governing equation, the Euler equation is adopted. The comparison indicates that the computed waves are in good agreement with the measured results and that the MAC method is useful. On the other hand, a critical condition for the appearance of sub-breaking waves derived from the in viscid instability analysis is applied to the calculated flow field around a blunt bow. It is confirmed that the derived condition detects well the appearance of sub-breaking waves.

• Natural Product Sciences
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• v.23 no.4
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• pp.270-273
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• 2017

A quantitative analysis of bakkenolide D in the different parts of Petasites japonicus and Farfugium japonicum was performed by HPLC. A gradient HPLC elution system with a mobile phase consisting of water: acetonitrile solution (20:80 to 0:100 for 45 min) was followed and an INNO $C_{18}$ column was used for the chromatographic separation. The injection volume, flow rate, and UV detection were $10{\mu}L$, 1 mL/min, and 290 nm, respectively. Results show that both species showed the highest amount of bakkenolide D in the roots being 107.203 and 166.103 mg/g for P. japonicas and F. japonicum, respectively. Content analysis on the different parts of both plants displayed remarkably lower values which ranged from 0.403 - 4.419 and 7.252 - 32.614 mg/g for P. japonicas and F. japonicum, respectively. The results show that the roots of both plants are rich in bakkenolide D showing a promising use in the development of nutraceuticals and industrial application of the compound.

• Korean Journal of Pharmacognosy
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• v.46 no.4
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• pp.352-364
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• 2015

The aim of this study was to quantitatively analyze for quality assessment of eighteen marker compounds, including homogentisic acid, 3,4-dihydroxybenzaldehyde, spinosin, liquiritin, hesperidin, ginsenoside Rg1, liquiritigenin, ginsenoside Rb1, glycyrrhizin, 6-gingerol, atractylenolide III, honokiol, costunolide, dehydrocostuslactone, atractylenolide II, nootkatone, magnolol, and atractylenolide I, in Hyangsayukgunja-tang using an ultra-performance liquid chromatography-electrospray ionization-mass spectrometer. The column for separation of eighteen marker components were used a UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}$) and kept at $45^{\circ}C$ by gradient elution with 0.1% (v/v) formic acid in water and acetonitrile as mobile phase. The flow rate and injection volume were 0.3 mL/min and $2.0{\mu}l$, respectively. The correlation coefficient of all marker compounds was ${\geq}0.9914$, which means good linearity, within the test ranges. The limits of detection and quantification values of the all analytes were in the ranges 0.04-1.11 and 0.13-3.33 ng/mL, respectively. As a result, five compounds, homogentisic acid, 3,4-dihydroxybenzaldehyde, spinosin, liquiritigenin, and atractylenolide I, in this sample were not detected and the amounts of the 13 compounds except for the 5 compounds were $8.10-6736.37{\mu}g/g$ in Hyangsayukgunja-tang extract.

• 한국가시화정보학회:학술대회논문집
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• 2004.12a
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• pp.65-74
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• 2004

Measurement of concentration distributions of suspended particles in a micro-channel is out of the most crucial necessities in the area of Lab-on-a-chip to be used for various bio-chemical applications. One most feasible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been successfully achieved so far due to various limitations in the light illumination and fluorescence signal detection. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having five(5) microns thickness by use of a micro focus laser line generator. The laser sheet beam illuminates an exact plane of concentration measurement field to increase the signal to noise ratio and considerably reduce the depth uncertainty. Nile Blue A was used as fluorescent dye for the present LIF measurement. The enhancement of the fluorescent intensity signals was performed by a solvent mixture of water $(95\%)$ and ethanol (EtOH)/methanol (MeOH) $(5\%)$ mixture. To reduce the rms errors resulted from the CCD electronic noise and other sources, an expansion of grid size was attempted from $1\times1\;to\;3\times3\;or\;5\times5$ pixel data windows and the pertinent signal-to-noise level has been noticeably increased accordingly.

• Mass Spectrometry Letters
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• v.3 no.4
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• pp.87-92
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• 2012

In this study, we explored a new approach for generating ions of organics and biomolecules using contactless atmospheric pressure ionization (C-API). That is, a tapered capillary (~20 cm) was connected to a syringe, which was coupled to a syringe pump for providing a given flow rate to introduce sample solution to the proximity of a mass spectrometer. The gas phase ions derived from analytes were readily formed in the capillary outlet, which was very close to the mass spectrometer (~1 mm). No external electric connection was applied on the capillary emitter. This setup is very simple, but it can function as an ion source. This approach can be readily used for the analysis of small molecules such as amino acids and large molecules such as peptides and proteins. The limit of the detection of this approach was estimated to be ~10 pM when using bradykinin as the sample. Thus, we believe that this approach should be very useful for being used as an alternative ion source because of its low cost, high sensitivity, simplicity, and ease of operation.

• The Korean Journal of Cytopathology
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• v.17 no.1
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• pp.18-26
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• 2006

Transitional cell carcinoma of the urinary bladder is common in the genitourinary tract. The gold standard for the diagnosis of bladder cancer has been cystoscopy, along with urine cytology. Cystoscopy is an invasive and relatively expensive technique. By comparison, urine cytology is easy to perform and specific for a diagnosis of bladder cancer, although less sensitive, especially in low-grade tumors. For this reason, there has been a need for superior noninvasive technology to increase our confidence in being able to detect bladder cancer. There are many reports of the various urinary tests that are available to facilitate the diagnosis. In this article, I reviewed the literature on urinary markers and tests that may be clinically useful, including fluorescence in situ hybridization, uCyt+/Immunocyte, the $BTA^{(R)}$ test, the NMP 22TM, the $FDP^{(R)}$ test, the telomerase activity test, the HA and HAse tests, and flow cytometry. Most of these tests have a higher sensitivity and specificity than cytology. However, urine cytology has the highest specificity, especially in individuals with a high-grade tumor. We conclude that no urinary markers or tests can replace the role of cystoscopy along with cytology in the diagnosis of transitional cell carcinoma of the bladder. However, some markers could be used adjunctively to increase the diagnostic accuracy during screening or during the postoperative follow-up examination of patients with bladder cancer.

• International Journal of Aeronautical and Space Sciences
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• v.12 no.3
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• pp.274-282
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• 2011

This paper is focused on dynamic modeling and control system design as well as vision based collision avoidance for multi-rotor unmanned aerial vehicles (UAVs). Multi-rotor UAVs are defined as rotary-winged UAVs with multiple rotors. These multi-rotor UAVs can be utilized in various military situations such as surveillance and reconnaissance. They can also be used for obtaining visual information from steep terrains or disaster sites. In this paper, a quad-rotor model is introduced as well as its control system, which is designed based on a proportional-integral-derivative controller and vision-based collision avoidance control system. Additionally, in order for a UAV to navigate safely in areas such as buildings and offices with a number of obstacles, there must be a collision avoidance algorithm installed in the UAV's hardware, which should include the detection of obstacles, avoidance maneuvering, etc. In this paper, the optical flow method, one of the vision-based collision avoidance techniques, is introduced, and multi-rotor UAV's collision avoidance simulations are described in various virtual environments in order to demonstrate its avoidance performance.