• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.183-191
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• 2023

This study was conducted experimentally to investigate the surface temperature of the heat sink, the air temperature in the flow channel and the sample temperature by changing the channel number of channel type heat sink and the air flow rate when heating and cooling the bio sample. The target temperature of the sample was 15℃ or less as the minimum value and 82℃ or more as the maximum value. In this study, the channel number of the heat sink(N = 1, 2, 4, 5, 10) and the air flow rate(Q=25, 42, 54m³/min) were varied. The bio sample was replaced with water, and the volume of water is 4mL. The size of the heat sink is 80x73x150mm and the material is aluminum. When cooling the sample, the surface temperature, the air temperature and the sample temperature were highly dependent on the number of channels and the flow rate. However, when the sample is heated, the surface temperature, air temperature and sample temperature do not depend on the number of channels and the flow rate. It was found that the conditions for satisfying the minimum temperature of 15℃ or less when cooling the sample were the number of channels N≥5 and the flow rate Q≥42m³/min. When heating the sample, the conditions to satisfy the maximum temperature of 82℃ or more are the number of channels N≤5 and the air flow rate Q≤42m³/min.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.472-477
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• 2011

The Forsythiae Fructus is an oriental medicine containing various lignans. In this study, the Forsythiae Fructus were extracted by hot water (Sample 1), hot water after bio-conversion using Lactobacillus strain (Sample 2-LP2, 2-LA, 2-LC, 2-LL, 2-BL and 2-LM) and 70% ethanol (Sample 3). Total polyphenol and flavonoid contents were improved by bio-conversion process using Lactobacillus strain, compared to water extract. Especially, sample 2-LL and 2-LA which had shown the high total polyphenol and flavonoid content in antioxidant activity. Also, sample 2-LL and 2-LA showed higher melanin generation inhibitory activity as of 55%, 53% in maximum extract concentration of $100{\mu}g/m{\ell}$. In the anti-inflammation test of the Forsythiae Fructus extracts, nitric oxide (NO) synthesis was inhibited. Specially, both 70% Forsythiae Fructus ethanol extract and sample 2-BL which have shown the relatively higher 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD) like activities. In conclusion, the Forsythiae Fructus extracts with bio-conversion process has effect of skin whitening and anti-inflammation activity than other extracts. It could be used as a valuable materials for functional cosmetics.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.54-60
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• 2006

In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.

• Applied Microscopy
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• v.45 no.4
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• pp.203-207
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• 2015

Sample preparation is very important for crystal structure analysis of novel nanostructured materials in electron microscopy. Generally, a grid dispersion method has been used as transmission electron microscope (TEM) sampling method of nano-powder samples. However, it is difficult to obtain the cross-sectional information for the tabular-structured materials. In order to solve this problem, we have attempted a new sample preparation method using focused ion beam. Base on this approach, it was possible to successfully obtain the electron diffraction patterns and high-resolution TEM images of the cross-section of tabular structure. Finally, we were able to obtain three-dimensional crystallographic information of novel zeolite nano-crystal of the tabular morphology by applying the new sample preparation technique.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.148-156
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• 2015

In this study the differences in the sample size and sample input changes as characteristics of bio-oil oak(Quercus variabilis), the oak 0.5~2.0 mm of the oak weighing 300~900g was processed into bio-oil via fast pyrolysis for 1.64 seconds. In this study, the physico-chemical properties of biooil using oak were investigated. Fast pyrolysis was adopted to increase the bio-oil yield from raw material. Although the differences in sample size and sample input changes in the yield of pyrolysis products were not significantly noticeable, increases in the yield of bio-oil accounted for approximately 60.3 to 62.1%, in the order of non-condensed gas, and biochar. When the primary bio-oil obtained by the condensation of the cooling tube and the seconary bio-oil obtained from the electric dust collector were measured separately, the yield of primary bio-oil was twice as higher than that of the secondary bio-oil. However, HHV (Higher Heating Value) of the secondary bio-oil was approximately twice as higher than that of the primary bio-oil by up to 5,602 kcal/kg. The water content of the primary bio-oil was more than 20% of the moisture content of the secondary bio-oil, which was 10% or less. In addition, the result of the elemental analysis regarding the secondary bio-oil, its primary carbon content was higher than that of the primary bio-oil, and since the oxygen content is low, the water content as well as elemental composition are believed to have an effect on the calorific value. The higher the storage temperature or the longer the storage period, the degree of the viscosity of the secondary bio-oil was higher than that of the primary bio-oil. This can be the attributed to the chemical bond between the polymeric bio-oil that forms during the storage period.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.194-194
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• 2004

• Genomics & Informatics
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• v.12 no.2
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• pp.50-57
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• 2014

We present a new next-generation sequencing-based method to identify somatic mutations of lung cancer. It is a comprehensive mutation profiling protocol to detect somatic mutations in 30 genes found frequently in lung adenocarcinoma. The total length of the target regions is 107 kb, and a capture assay was designed to cover 99% of it. This method exhibited about 97% mean coverage at $30{\times}$ sequencing depth and 42% average specificity when sequencing of more than 3.25 Gb was carried out for the normal sample. We discovered 513 variations from targeted exome sequencing of lung cancer cells, which is 3.9-fold higher than in the normal sample. The variations in cancer cells included previously reported somatic mutations in the COSMIC database, such as variations in TP53, KRAS, and STK11 of sample H-23 and in EGFR of sample H-1650, especially with more than $1,000{\times}$ coverage. Among the somatic mutations, up to 91% of single nucleotide polymorphisms from the two cancer samples were validated by DNA microarray-based genotyping. Our results demonstrated the feasibility of high-throughput mutation profiling with lung adenocarcinoma samples, and the profiling method can be used as a robust and effective protocol for somatic variant screening.

• Food Science and Preservation
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• v.16 no.3
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• pp.427-434
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• 2009

We collected glasswort (Salicornia herbacea L.) from the Jollanam-do area (Hwangsan-myeon in Haenam, Jeungdo-myeon in Sinan, and Yeomsan-myeon in Yeonggwang) from June to October 2007, and analyzed levels of total amino acids, free amino acids, and total polyphenolic compounds and electron donating ability and SOD-like activity. The total amino acid content was $3,338.75{\sim}4,491.63\;mg$/100 g in the sample from Haenam, $3,086.48{\sim}3,782.89\;mg$/100 g in the sample from Sinan, and $3,134.3{\sim}4,364.17\;mg$/100 g in the sample from Yeonggwang. Proline was the main free amino acid from June through to September, and the level increased during June, the early period of maturation, and then decreased with further ripening. The total content of free amino acids was $472.75{\sim}1,080.98\;mg$/100 g in the sample from Haenam, $440.46{\sim}621.77\;mg$/100 g in the sample from Sinan, and $387.64{\sim}669.28\;mg$/100 g in the sample from Yeonggwan. Total polyphenolic compound level was $11.1{\sim}15.61\;mg/g$ in the sample from Haenam, $12.71{\sim}21.03\;mg/g$ in the sample from Sinan, and $13.13{\sim}22.28\;mg/g$ in the sample from Yeonggwang. Electron donating ability was 53.8.70.9% in the sample from Haenam, $62.7{\sim}88.8%$ in the sample from Sinan, and $63.0{\sim}72.7%$ in the sample from Yeonggwang. SOD-like activity was $28.7{\sim}41.0%$ in the sample from Haenam, 28.5{\sim}36.5% in the sample from Sinan, and 23.5.39.6% in the sample from Yeonggwang.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2293-2298
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• 2010

Focused electrospray (FES) deposition method is presented for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. FES ion optics consists of two cylindrical focusing electrodes capped with a truncated conical electrode through which an electrospray emitter passes along the cylindrical axis. A spray of charged droplets is focused onto a sample well on a MALDI target plate under atmospheric pressure. The shape and size distributions of matrix crystals are visualized by scanning electron microscope and the mass spectra are obtained by time-of-flight mass spectrometry. Angiotensin II, bradykinin, and substance P are used as test samples, while $\alpha$-cyano-4-hydroxycinnamic acid and dihydroxybenzoic acid are employed as matrices. FES of a sample/matrix mixture produces fine crystal grains on a 1-3 mm spot and reproducibly yields the mass spectra with little shot-to-shot and spot-to-spot variations. Although FES greatly stabilizes the signals, the space charge due to matrix ions limits the detection sensitivity of peptides. To avoid the space charge problem, we adopted a dual FES/FES mode, which separately deposits matrix and sample by FES in sequence. The dual FES/FES mode reaches the detection sensitivity of 0.88 amol, enabling ultrasensitive of peptides by homogeneously depositing matrix and sample under atmospheric pressure.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.463-467
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• 2007

Structure and optical properties of ZnO epilayers grown on oxygen- and hydrogen-plasma treated sapphire substrates by plasma-assisted molecular beam epitaxy (denoted as samples A and B, respectively) have been investigated by various techniques. The crystal quality and structural properties of the surface for the ZnO epilayers were investigated by high-resolution X-ray diffraction and atomic force microscope. For investigating the optical properties of excitonic transition of ZnO, we carried out photoluminescence experiments as a function of temperature. The free exciton, bound exciton emission and their phonon replicas were investigated as a function of temperature from 10 to 300 K, and the intensity of excitonic PL peak emission from the sample A is found to be higher than that of sample B. From the results, we found that sample A has better crystal structure quality and optical properties as compared to sample B. The number of oxygen vacancies may be decreased in sample A, resulting in an enhancement of the crystal quality and a higher intensity of excitonic emission band as compared to sample B.