• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.126-134
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• 2015

Glycyrrhiza uralensis Fischer is one of the most commonly used herbs. Recently, the stem and leave of the plant have been interested in physiological activities because the aerial parts have been thrown away. Finding out cultivation method of Glycyrrhiza uralensis Fischer to improve chemical ingredients and biological activities has been tried these days. In this study, different wavelengths of light emitting diode (LED) were used for a cultivation of Glycyrrhiza uralensis Fischer. Antioxidant activities and inhibitory effect on mutagenecity of samples were evaluated. The stem and leave cultivated under blue light (BL-0) showed the strongest antioxidant activities of $3.02{\pm}0.13{\mu}g/ml$ ($EC_{50}$) and $2.18{\pm}0.18{\mu}g/ml$ ($EC_{50}$) in DPPH and ABTS radical scavenging test, respectively. Total phenolic content of BL-0 was $2.93{\pm}0.11g/100g$, the highest value between cultivation conditions. However, antioxidant activities of the stem and leave cultivated under red light were the weakest between samples. All of the stem and leave used in this study showed inhibitory effect on mutagenecity of 1-nitropyrene. BL-0 showed stronger inhibitory effects on mutagenicity of Trp-P-1, Trp-P-2, and AFB1 than samples cultivated under other conditions. Only on mutagenecity of 2-aminoanthracene, the stem and leave cultivated at 1 m apart from red light (RL-1) showed the strongest inhibitory effect. These results indicate that blue LED might be the most effective condition for improvement of physiological activities for the aerial parts of Glycyrrhiza uralensis Fischer in cultivation. The components were identified with GC/MS. Cytidine was detected only in RL-1 at 25 min of retention time and 2-bromotrimethylene glycol was detected only in BL-0 at 37 min.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.328-335
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• 2010

In this paper, an efficient algorithm and area-efficient hardware architecture have been proposed for $2{\times}2$ MIMO-OFDM based WLAN baseband modem with two transmit and two receive antennas. To enhance the performance of the receiver, the efficient timing synchronization algorithm and symbol detector based on MML algorithm are presented. Also, by sharing the hardware block with multi-stage pipeline structure and using the complex multiplier based on polar-coordinate, the complexity of the proposed architecture is dramatically decreased. The proposed area-efficient hardware design was designed in hardware description language (HDL) and synthesized to gate-level circuits using 0.13um CMOS standard cell library. As a result, the complexity of the proposed modem receiver is reduced by 56% over the conventional architecture.

• Journal of Food Hygiene and Safety
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• v.15 no.3
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• pp.262-266
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• 2000

The polymerase chain reaction was used to selectively detect sequences within the fimbrial antigen of Salmonella enteritidis. Sterile milk was artificially inoculated with known amount of S. enteritidis and then DNA was extracted with guanidine thiocyanate/phenol/chloroform, followed by PCR. A detection limit of as few as 100 colony forming unit (cfu) per 0.5 ml milk was obtained with this method. For the whole procedure, it took only 5 h. A semi-quantitative polymerase chain reaction assay which allows an estimation of colony forming unit of S. enteritidis was developed. Known amount of standard plasmid pGem-4Z-Sef B(-) containing cloned S. enteritidis fimbrial antigen gene was co-amplified with Salmonella genomic DNA isolated from artificially inoculated milk. The same set of primers were used for the amplification and the products were cleaved with Bam HI. The concentration of the target DNA could be estimated by comparing the intensity of the two bands after electrophoresis. The PCR-based protocol described in this paper provides a rapid, simple, and sensitive method for detecting S. enteritidis in milk.

• Analytical Science and Technology
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• v.7 no.3
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• pp.413-419
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• 1994

The determination of the neuromuscular blocking agents vecuronium bromide(VeBr) in biological fluids has been investigated. The method depends on the formation of insoluble red complex between vecuronium bromide and rose bengal in aqueous layer. The amount of vecuronium bromide was calculated from that of extracted rose bengal which was determined by spectrofluorimetry or HPLC/fluorescence detection method. It was possible to analyze VeBr in the range of $2{\sim}32{\mu}g/ml$(r=0.998 for water soln., 0.999 for urine, 0.996 for plasma). This method was applied to the analysis of VeBr in biological fluids, urine and plasma.

• Journal of fish pathology
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• v.13 no.1
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• pp.61-66
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• 2000

A method was developed for concentrating fish pathogenic virus from sea water using membrane ultrafiltration system and centricon. The method consists of passing large volumes (Ca. 20 liter) of sea water through ultrafiltration (PAN) filter followed by cross-flow filtration method and centrifugation use the centricon (Plus-20). This procedure permitted the processing of 20 liter of sea water which resulted in a 20,000-fold reduction in the volume of water and greater than 90% recovery of the seeded MABV.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.426-426
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• 2012

본 연구에서는 GaAs p-i-n 접합 구조에 InAs 양자점을 삽입한 양자점 태양전지(Quantum Dot Solar Cell; QDSC)의 내부 전기장(internal electric field)을 조사하기 위하여 Photoreflectance (PR) 방법을 이용하였다. QDSC 구조는 GaAs p-i-n 구조의 공핍층 내에 8주기의 InAs 양자점 층을 삽입하였으며 각 양자점 층은 40 nm 두께의 i-GaAs로 분리하였다. InAs/GaAs QDSC는 분자선박막 성장장치(molecular beam epitaxy; MBE)를 이용하여 성장하였다. 이 때 양자점의 형성은 InAs 2.0 ML(monolayer)를 기판온도 $470^{\circ}C$에서 증착하였다. QDSC 구조에서 여기광원의 세기에 따른 전기장의 변화를 조사하였다. 아울러 양자점 층 사이의 i-GaAs 층 내에 6.0 nm의 AlGaAs 퍼텐셜 장벽(potential barrier)을 삽입하여 퍼텐셜 장벽 유무에 따른 전기장 변화를 조사하였다. PR 측정에서 여기광원으로는 633 nm의 He-Ne 레이저를 이용하였으며 여기광의 세기는 $2mW/cm^2$에서 $90mW/cm^2$까지 변화를 주어 여기광세기 의존성실험을 수행하였다. 여기광의 세기가 증가할수록 photovoltaic effect에 의한 내부 전기장의 변화를 관측할 수 있었다. PR 결과로부터 p-i-n 구조의 p-i 영역과 i-n 접합 계면의 junction field를 검출하였다. p-i-n의 i-영역에 양자점을 삽입한 경우 PR 신호에서 Franz-Keldysh oscillation (FKO)의 주파수가 p-i-n 구조와 비교하여 변조됨을 관측하였다. 이러한 FKO 주파수성분은 fast Fourier transform (FFT)을 이용하여 검출하였다. FKO의 주파수 성분들은 고전기장하에서 electron-heavyhole (e-hh)과 electron-lighthole (e-lh) 전이에 의해 나타나는 성분으로 확인되었다.

• Korean Journal of Environmental Agriculture
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• v.17 no.1
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• pp.22-25
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• 1998

These studies were conducted to develope analysis method of herbicide quizalofop-ethyl by Gas Liquid Chromatography(GLC) and Enzyme-Linked Immunosoment Assay(ELISA) in soil and plant. Quizalofop produced by hydrolysis of quizalofop-ethyl was conjugated with bovine serum albumin(BSA). Quizalofop antibody was developed in rabbits by using BSA conjugation. Antibody titer, incubation temperature, and incubation time was 32,000, $37^{\circ}C$ and 4hours respectively. Minimum detection limit of quizalofop-ethyl by ELISA was 5ppb. Quizalofop-ethyl recovery from soil by ELISA was more than 95percent. Minimum detection limit of quizalofop-ethyl by GLC was 5ppb. Quizalofop-ethyl recovery from soil by GLC was from 89 percent to 100 percent. Minimun detection limit of quizalofop-ethyl by HPLC was 100ppb. Quizalofop-ethyl recovery from soil by HPLC was 89.6 percent.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.228-236
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• 2008

Validation of viral safety is essential in ensuring the safety of mammalian cell culture-derived biopharmaceuticals, because numerous adventitious viruses have been contaminated during the manufacture of the products. Mammalian cells are highly susceptible to Reovirus type 3 (Reo-3), and there are several reports of Reo-3 contamination during the manufacture of biopharmaceuticals. In order to establish the validation system for the Reo-3 safety, a real-time RT-PCR method was developed for quantitative detection of Reo-3 in cell lines, raw materials, manufacturing processes, and final products as well as Reo-3 clearance validation. Specific primers for amplification of Reo-3 RNA was selected, and Reo-3 RNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be $3.2{\times}10^0\;TCID_{50}/ml$. The real-time RT-PCR method was proven to be reproducible and very specific to Reo-3. The established real-time RT-PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with Reo-3. Reo-3 RNA could be quantified in CHO cell as well as culture supernatant. When the real-time RT-PCR assay was applied to the validation of virus removal during a virus filtration process, the result was similar to that of virus infectivity assay. Therefore, it was concluded that this rapid, specific, sensitive, and robust assay could replace infectivity assay for detection and clearance validation of Reo-3.

• Journal of Life Science
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• v.27 no.8
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• pp.864-872
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• 2017

Equine chorionic gonadotropin (eCG) consists of highly glycosylated ${\alpha}-$ and ${\beta}-subunits$ and is a unique member of the gonadotropin family, because it elicits the response characteristics of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in species other than the horse. To directly assess the biological function of $rec-eCG{\beta}/{\alpha}$, we constructed mammalian expressing vectors of equine luteinizing hormone/chorionic gonadotropin receptors (eLH/CGR). The activity of $rec-eCG{\beta}/{\alpha}$ in vitro assayed in transient transfected CHO-K1 cells and in stably transfected PathHunter Parental cells with eLH/CGR was investigated. $rec-eCG{\beta}/{\alpha}$ was efficiently secreted in the CHO-K1 suspension cell media, and the quantity detected was about 200 mIU/ml from 1 to 7 days after transfection. In the western blot analysis, the $rec-eCG{\beta}/{\alpha}$ protein was broadly identified to be about 40~45 kDa molecular weight. The cAMP stimulation in CHO-K1 cells expressing eLH/CGR was determined to evaluate the activity of $rec-eCG{\beta}/{\alpha}$. The cAMP concentration increased in direct proportion to the concentration of the $rec-eCG{\beta}/{\alpha}$. The $EC_{50}$ value in the transient transfected CHO-K1 cells was $8.1{\pm}6.5ng$. The stable cell lines of eLH/CGR were established in the PathHunter Parental cells expressing ${\beta}-arrestin$. We found that $rec-eCG{\beta}/{\alpha}$ had full LH activity in the PathHunter Parental cells expressing eLH/CGR. The $EC_{50}$ value in transient and stable cells was $5.0{\pm}4.7ng/ml$ and $4.5{\pm}5.2ng/ml$, respectively. These results suggest that $rec-eCG{\beta}/{\alpha}$ has a biological activity in a cell expressing eLH/CGR. These stable cells expressed in PathHunter Parental cells could be useful for elucidating the functional mechanisms of deglycosylated $rec-eCG{\beta}/{\alpha}$ mutants.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.4
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• pp.358-367
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• 1983

Antibiotic-resistant strains of Salmonella typhimurium and Klebsiella pneumoniae died readily after their addition to raw sewage, but they grew in sterilized sewage. The decline was not a result of antibiotic stresses, and because the bacteria were able to survive in large numbers for at least 15 days in solutions containing no organic nutrients, it was not a result of competition. Toxin production, bacteriophages, and Bdellovibrio did not cause the disappearance of the two bacterial species. A decline was also evident if the sewage was first passed through a $3-{\mu}m$ filter or treated with cycloheximide or cycloheximide plus nystatin, but protozoa developed under these conditions. Little or no decline occurred if the sewage was filtered and treated with the eucaryotic inhibitors before adding S. typhimurium or K. pneumoniae, and protozoa were not detected. S. typhimurium increased in abundance if cycloheximide, streptomycin, and erythromycin or large amounts of glucose were added to sewage. Tetrahymena thermophilus did not significantly reduce the population of S. typhimurium in buffer when the density of the bacterium was about $10^4/ml$. However, when more than $10^8$ Enterobacter agglomerans cells per ml were added to the buffer, T. thermophilus reduced the abundance of E. agglomerans and S. typhimurium to $10^6$ and 10/ml, respectively. The density of S. typhimurium was further decreased by a second increment of E. agglomerans cells. The disappearance of S. typhimurium and K. pneumoniae from sewage thus is the result of predation by protozoa. It is proposed that predators will eliminate a prey species from a natural environment when an alternate prey is present at concentrations above the threshold number for active feeing by the predator and when the rate of growth of the prey is less than the rate of predation.