• 한국물환경학회지
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• 제29권6호
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• pp.790-798
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• 2013

Benthic macroinvertebrates are widely used as biological indicators for assessing the integrity of aquatic ecosystem. However, sampling has usually been done with fixed sample size due to time consuming and costly process. This study was conducted to find out the influence of sample size on the biological indices (H' DI, R1, J, EPT, ESB and BMI) of benthic macroinvertebrates. The 15 replicate samples were quantitatively collected from each 3 different site of two mountain streams in May, 2011. With the replicate data, we combined the abundance of each species with all the possible combinations of the sample size. Along with the increase of sample size, the number of species increased continuously and did not converge. BMI showed little difference whereas other biological indices increased or decreased.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.182-184
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• 1998

PCR was used for quantitative counting of Bifidobacterium spp. in a sample mixed with Lactobacillus acidophilus using two primer sets; one set for universal priming and the other set for Bifidobacterium specific priming. DNA products from two independent PCRs with DNA extracted from the mixed sample were found to be easily distinguishable from each other by agarose gel electrophoresis. The concentrations of PCR products correlated with the total number of bacteria and with the number of Bifidobacterium spp. present in the sample.

• 한국물환경학회지
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• 제31권6호
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• pp.610-618
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• 2015

This study was conducted to find out the influence of sample size (accumulated survey areas) on the seven biological indices of benthic macroinvertebrates. BMI, the index similar to Zeilika-Marvan’s saprobic index, tended to be independent on the variations of sample size. The other indices (Shannon-Weaver’s diversity, Margalef’s richness, Menhinick’s richness, Pielou’s evenness, and Lenat’s EPT index) showed the considerable variations along with the increase of sample size and environmental conditions. To get the appropriate index values, it should be sampled at least 6 replicates more based on 30×30cm Surber sampler. In addition, the habitat heterogeneity index of benthic macroinvertebrates suggested in this study, it will be able to be used for evaluating the heterogeneity of habitats.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.179-188
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• 1991

An HPLC assay method of a drug to be applied to the pharmacokinetic studies of the drug should be completely validated. The validation process for an HPLC assay method in a biological sample was discussed using the data obtained from the development of HPLC method for the simultaneous quantitation of verapamil and norverapamil in human serum. The validation criteria included were specificity, linearity, accuracy, precision, sensitivity, recovery, drug stability, and ruggedness of an assay method.

• 한국작물학회지
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• 제51권1호
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• pp.89-94
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• 2006

Traditionally fatty acid composition used to be analysed by a GC and the sample preparation process includes lipid extraction from sample and subsequent methyl esters preparation, which are time-consuming and cumbersome. As an alternative, simultaneous extraction/methylation methods are being developed for rapid and simplified sample preparation. To optimize one-step extraction/methylation method for analysis of fatty acid composition in brown rice, various reaction factors such as sample to reaction solution ratio, reaction time and temperature, shaking intensity were changed and resultant fatty acid composition data were evaluated in comparison with previous reports. The ratio of sample weight to reaction solution volume was the most critical factor in that higher sample to reaction solution ratio caused overestimation of palmitic acid and linoleic acid composition, resulting in underestimation of oleic acid. Lower reaction temperature also induced overestimation of linoleic acid and underestimation of oleic acid. Reaction duration and the intensity of shaking prior to and during the reaction, however, caused no significant changes in analysis results. In conclusion, the optimum condition was mixing 5 grains (about 0.2 g) of brown rice with $680{\mu}L$ of extraction/methylation mixture and $400{\mu}L$ of heptane, followed by reaction at $80^{\circ}C$ for 2 hours.

• 환경생물
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• 제22권3호
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• pp.376-380
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• 2004

In August 2003, the water quality of offshore waters along the Incheon coast of Korea was evaluated by biological evaluation using gametes, embryos and early development systems of a starfish species (Asterina pectinifera). As the result of performing biological evaluations on seawater samples from a total thirteen sites, the formation rate of normal larva was 16-68%. At seawater sample from site 5 and 13, formation rate of normal larva averaged 16%, the most abnormal rate hindering the early embryo development of the experimental animal, while that of site 3 averaged 68%, the highest formation rate of normal larva. At seawater sample from site 2, 4, 7, 9, 10, 11, 12, formation rate of normal larva averaged 33-54%, those which damage the development of early embryos slightly. At seawater sample from site 1, 5, 6, 8, 13, formation rate of normal larva averaged 16-28%, those which damage the development of early embryos strongly.

• 대한의용생체공학회:의공학회지
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• 제14권3호
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• pp.273-282
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• 1993

This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

• 한국유변학회:학술대회논문집
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• 한국유변학회 2006년도 춘계 학술발표회 논문집
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• pp.61-64
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• 2006

Soft materials, such as polymer solutions, gels and filamentous protein materials in cells, show complicated behavior due to their complex structures and dynamics with multiple characteristic time and length scales. Several complementary techniques have been developed to measure viscoelastic of soft materials. Especially, particle tracking microrheology, using the Brownian motion of particles in a medium to get rheological properties, has recently been improved both theoretically and experimentally. Compared to other conventional methods, video particle tracking microrheology has some advantages such as small sample volume, detecting spatial variation of local rheological properties, and less damage to sample materials. With these advantages, microrheology is more suitable to measure the properties of complex materials than other mechanical rheometries.

• 생약학회지
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• 제31권2호
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• pp.130-141
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• 2000

The dried roots of Rehmannia glutinosa (RG) have been used in the traditional medicine for treatment of diabetes, fever and dysuria, etc. In order to investigate the quality evaluation of the dried roots of RG, we conducted the physico-chemical and biological evaluation method. The amount of catalpol from commercial samples is very diverse about $0.00{\sim}3.89%$ by using HPLC method, because it is easily decomposed by processing of RG. So, we should try to identify the correlation with the contents of catalpol and biological activities of RG. We chose 3 samples which were a wide difference of catalpol contents between each sample (Sample-I; 3.4%, Sample-II; 2.8%, Sample-III; 0.05%). Sample-I and Sample-II were found to be more effective than Sample-III on the DPPH free radical scavenging effect and inhibitory effect on $H_2O_2-catalyzed$ lipid peroxidation in rat liver in vitro. And, Sample-I and Sample-II exhibited more significant effects than Sample-III on accelerating actions of the small and large intestinal transport, and diuretic action in mice. So, it is suggested that the quantitative determination of catalpol should be required for the tandardization of the dried roots of RG.

• Journal of Applied Biological Chemistry
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• 제43권2호
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• pp.94-100
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• 2000

An analytical method was developed to determine abamectin and milbemectin residues in apple, pear, and citrus using HPLC with ultraviolet absorption detection. Abamectin and milbemectin were extracted with methanol from apple, pear, and citrus samples. The extract was diluted with saline water and dichloromethane partition was followed to recover the compounds from the aqueous phase. Florisil column chromatography and aminopropyl solid-phase extraction were employed as cleanup methods to remove most of co-extractives from the sample extract. Reverse-phase HPLC using an octadecylsilyl column was successfully applied to separate and quantitate abamectin and milbemectin residues in sample extracts at the wavelength of 245 nm. Recoveries of abamectin and milbemectin from fortified samples ranged 80.4~90.3% and 90.9~96.8%, respectively. Relative standard deviations of the analytical method were less than 10% for both acaricides. Detection limit of the analytical method was 0.003 mg/kg sample for all the analytes. The proposed method was reproducible and sensitive enough to evaluate terminal residues of abamectin and milbemectin in apple, pear, and citrus.