• Mass Spectrometry Letters
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• 제6권4호
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• pp.105-111
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• 2015

Sixteen compounds of Neobalanocarpus heimii were successfully identified directly from their plant extract using a triple quadrupole LC-MS/MS system. In order to fulfil the objectives of this work, a series of stilbene oligomers of various degrees of condensation were isolated and their structure are characterized. Out of these, four are resveratrol dimers, three trimers, and nine tetramers. The isolation process was done on a fully automated semi-preparative HPLC system. Their structures were elucidated on the basis of 1D- and 2D-NMR as well as MS data. The mass fragmentation patterns of the compounds were recorded and a retrievable in-house library was built to keep the data. In order to demonstrate the potential of this approach, the polyphenolic crude extract was analysed with the LC-MS/MS system and the MS/MS spectra extracted for each chromatographic peak of interest. The fragmentation patterns were compared with those of anticipated pure compounds that were previously recorded. All compounds were successfully identified. It is therefore believed that the LC-MS/MS potential for dereplication of structurally similar compounds in a crude mixture was thus firmly established.

• 보건교육건강증진학회지
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• 제31권1호
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• pp.13-26
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• 2014

Objectives: This study aimed to assess whether metabolic syndrome (MS) is related to osteoporosis and investigate the association between the MS components and bone mineral density (BMD). Methods: We conducted a cross-sectional study for 4,365 women aged over 50 years who completed health examination from 2008 to 2012 in Korea Association of Health Promotion Gangwon Branch. Height, body weight, waist circumference, blood pressure, fasting plasma glucose, serum lipid profiles, and BMD were measured. Results: Obesity measured as body mass index (BMI) was detrimental to all of the MS components but positively correlated with BMD at three skeletal sites (lumbar spine, femoral neck, and total hip). There were no significant differences in the MS prevalence between women without osteoporosis and those with osteoporosis. In age-adjusted analysis, women with MS had significantly higher BMD at three sites when compared to those without MS. After adjusting for BMI and age, these significances disappeared, such that MS was not associated with higher BMD. Conclusions: Our findings indicate that obesity increases the risk of MS whereas underweight increases that of osteoporosis. The association between MS and higher BMD was explained by the higher BMI in those with MS. MS may not be associated with osteoporosis.

• 제어로봇시스템학회논문지
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• 제12권11호
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• pp.1144-1155
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• 2006

Digital communication networks have become a core technology in advanced building automation systems. BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet adopts Master-Slave/Token-Passing(MS/TP) protocol as one of its field level networks. In this study, we introduce a method of implementing a bandwidth allocation scheme in the MS/TP protocol. The bandwidth allocation scheme improves the capability of real-time communication of the original MS/TP protocol. The bandwidth allocation scheme introduced in this paper can be easily implemented in the existing MS/TP protocol with a slight modification. In this study, we actually developed the hardware and firmware of the modified MS/TP communication module in which the bandwidth allocation scheme is implemented. Using the modified MS/TP communication module, we developed an experimental model in order to examine the validity of the bandwidth allocation scheme in the MS/TP protocol. Experimental results show that the modified MS/TP protocol satisfies the requirements of real time communication for periodic and urgent messages of BACnet communication services.

• Journal of Positioning, Navigation, and Timing
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• 제9권4호
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• pp.337-345
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• 2020

In this paper, an efficient signal tracking method to simultaneously track both GPS L1 C/A and Galileo E1B CBOC(6,1,1/11) using a low cost GPU is proposed. In the existing method that each GNSS signal is processed within 1 ms, more than 2 ms processing time is required in GPU to process 4 ms CBOC signal. It means that real time operation is possible if only Galileo E1B CBOC signal is concerned. But when both GPS C/A and Galileo CBOC is required, it cannot process GPS C/A signal in real time. To process 1 ms GPS C/A and 4 ms Galileo CBOC signal in real time, 4 ms Galileo CBOC signal is divided into 4 by 1 ms signal block in the proposed method. Specially, a buffer that simultaneously manages 1 ms and 4 ms signals is designed. In addition, a module that accumulates the 1 ms correlation value of the Galileo CBOC by 4 ms and passes it to the PLL and DLL is implemented. The operation and performance are evaluated with real measurements in the GPU based SDR. The experimental results show that tracking of more than 16 satellites of GPS C/A and Galileo E1B is possible using the proposed method.

• 분석과학
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• 제23권1호
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• pp.54-59
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• 2010

액체크로마토그래피/질량분석법(LC/MS)을 이용하여 화장품에 들어있는 파라벤류등을 동시 분석하였다. 화장품 시료를 메탄올에 직접 용해시키고 $0.45\;{\mu}m$ 필터로 여과하여 메탄올/물을 이동상으로 하여 Extend $C_{18}$의 비극성 컬럼을 사용하여 기울기 용리 조건에서 12분 안에 분리하여 SIM(selected ion monitoring)방법으로 정량하였다. LC/MS 분석결과 검량선은 $0.05-10\;{\mu}g$/mL 농도범위에서 $r^2$=0.9993의 상관계수를 갖는 좋은 직선성을 나타내었으며, 검출한계는 $0.01\;{\mu}g$/mL 이었다.

• Mass Spectrometry Letters
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• 제4권4호
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• pp.79-82
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• 2013

Various types of alkaloids observed in several herbal medicines were analyzed by electrospray ionization tandem mass spectrometry in positive ion mode. In the present study, MS/MS spectralpatterns were investigated for eight-types of alkaloids (aporpine, protoberberine, tetrahydroprotoberberine, benzylisoquinoline, protopine, phthalide, morpine, and bisbenzylisoquinoline). For aporpine- and protoberberine-type alkaloids, main fragmentations occurred at substituted groups on rigid ring structures, not showing ring fusion. Interesting fragmentations due to iminolization and retro-Diels-Alder (RDA) reaction were observed in MS/MS spectra of protopine- and tetrahydroprotobereberine-type alkaloids. Also, several types of fragmentations such as inductive cleavage and ${\alpha}$-cleavage, or bond cleavage between two ring structures were observed depending on their structural characteristics. These fragmentation patterns are expected to allow instant classification of the specific alkaloid type in various MS/MS spectra of alkaloids.

• Journal of Acupuncture Research
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• 제31권3호
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• pp.57-65
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• 2014

Objectives : The aim of this report was to investigate the effects of scalp acupuncture on central post-stroke pain. Methods : We treated a patient with central post-stroke pain from Lt thalamo-geniculate artery territory infarction with scalp acupuncture(MS6 and MS7) and usual treatment of Korean medicine. We evaluated pain severity using numerical rating scale(NRS). The scalp acupuncture was performed once a day for 3 weeks. Results : After 15th treatment of scalp acupuncture, NRS decreased from 8 to 3. Conclusions : This result suggests that scalp acupuncture(MS6 and MS7) is effective in treating central post-stroke pain. We hope that more clinical data and studies are to be done for efficient application.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1097-1102
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• 2002

The mass spectrometry using an ion trap tandem mass spectrometer has been investigated to find optimum conditions for the analysis of benzo(a)pyrene (3,4-benzpyrene). The applicability to a real soil sample was also investigated to verify the usef ulness of the MS/MS (or collision induced dissociation, CID) analysis. The optimum CID condition was 1.5 and 0.45 for the RF excitation voltage and the q value, respectively. For comparison, CID and EI were applied to the analysis of a soil sample. CID analysis was more sensitive than EI analysis of the soil sample. The limit of detection (LOD) of benzo(a)pyrene was 3.18 ng mL-1 and 0.85 ng mL,-1 for EI and MS/MS analysis, respectively. The precision at the soil sample for EI and CID showed relative standard deviations of 6.1% and 4.1%, respectively, and the concentrations were 168 ㎍ kg-1 and 162 ㎍ kg-1 , respectively.

• 분석과학
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• 제36권1호
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• pp.12-21
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• 2023

Protein glycation is vital to aging and disease. However, glycated proteins are low-abundant in plasma, rendering them difficult to identify using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Many studies have analyzed glycated peptides with high reproducibility. Here, glycated peptides in human serum were analyzed by LC-MS/MS using data-dependent acquisition (DDA) and parallel reaction monitoring (PRM). Boronic acid (BA) enrichment of in vitro glycated human serum peptides was performed. BA enrichment identified the most glycated peptides, and the glycated peptides of the more diversified proteins, excluding albumin, were analyzed. In PRM, glycated albumin PSMs were the most common, and this method exhibited the best reproducibility. The results of this study could help compare methods for identifying glycation-related biomarkers.

• 분석과학
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• 제37권1호
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• pp.1-11
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• 2024

In agricultural households cultivating vegetables and fruits, the use of various pesticides to protect crops from diseases and pests or to control weeds is widely practiced enhancing quality and productivity. However, pesticides can pose a threat to consumer health by remaining on the food surface or migrating into the food interior. Households commonly peel off skins, wash with water, or use chemical methods to remove foreign substances including residual pesticides on the food surface. In this study, we measured the washing rate by comparing the pesticide concentrations before and after washing in the leafy vegetable perilla leaves and the fruits strawberries and apples, which were intentionally exposed to pesticides. We compared washing rates using tap water, a baking soda solution, and a commercially available food-specific cleaning solution. The target pesticides for analysis were azoxystrobin, bifenthrin, boscalid, difenoconazole, flubendiamide, and indoxacarb, and the residual pesticide analysis was performed using GC-MS/MS or LC-MS/MS. The removal rates of pesticides were highest with the food-specific cleaner, followed by baking soda and tap water in order.