• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.135-139
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• 2012

This study was designed to evaluate the physicochemical properties and biological activities of steamed and fermented Codonopsis lanceolata. The treatments included NS-NF (non-steamed and non-fermented), NS-LF (non-steamed and L. rhamnosus fermented), S-NF (steamed and non-fermented), and S-LF (steamed and L. rhamnosus fermented). Total polyphenol amounts of S-NF and S-LF were significantly increased to more than 26 mg GAE/g. The highest DPPH scavenging activities were observed for S-NF and S-LF, showing $EC_{50}$ values of 0.8 and 0.6 mg/mL, respectively. The growths of Staphylococcus aureus, Listeria monocytogenes, Salmonella Typhimurium, and Shigella boydii were effectively inhibited by S-LF (MIC < 9 mg/mL). The NS-LF and S-LF ($EC_{50}$ <6 mg/mL) effectively inhibited ${\alpha}$-Glucosidase and tyrosinase activities compared to NS-NF ($EC_{50}$ <17 mg/mL). The S-LF exhibited the highest acetylcholinesterase (AChE) inhibitory activity ($IC_{50}$ <32 mg/mL). Therefore, the results suggest that the application of the steaming process combined with probiotic fermentation can effectively enhance the biological and pharmacological activities in C. lanceolata.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.285-291
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• 2005

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is the viral RNA-dependent RNA polymerase (RdRp), which is the essential catalytic enzyme for the viral replication and is an appealing target for the development of new therapeutic agents against HCV infection. A small amount of serum from a single patient with hepatitis C was used to get the genome of a Korean HCV isolate. Sequence analysis of NS5B 1701 nucleotides showed the genotype of a Korean isolate to be subtype 1b. The soluble recombinant HCV NS5B polymerase lacking the C-terminal 24 amino acids was expressed and purified to homogeneity. With the highly purified NS5B protein, we established in vitro systems for RdRp activity to identify potential polymerase inhibitors. The rhodanine family compounds were found to be potent and specific inhibitors of NS5B from high throughput screening (HTS) assay utilizing the scintillation proximity assay (SPA) system. The binding mode of an inhibitor was analyzed by measuring various kinetic parameters. Lineweaver-Burk plots of the inhibitor suggested it binds not to the active site of NS5B polymerase, but to an allosteric site of the enzyme. The activity of NS5B in in vitro polymerase reactions with homopolymeric RNA requires interaction with multiple substrates that include a template/primer and ribonucleotide triphosphate. Steady-state kinetic parameter, such as Km, was determined for the ribonucleotide triphosphate. One of compounds found interacts directly with the viral polymerase and inhibits RNA synthesis in a manner noncompetitively with respect to UTP. Furthermore, we also investigated the ability of the compound to inhibit NS5B-directed viral RNA replication using the Huh7 cell-based HCV replicon system. The investigation is potentially very useful for the utility of such compounds as anti-hepatitic agents.

• Journal of the Korea Society of Computer and Information
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• v.13 no.7
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• pp.189-197
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• 2008

ENS-2 simulator is the most widely-used simulator in the research of wired/wireless communication. Since an IEEE 802.11 module has been implemented in NS-2. much research using this module has been done for various MAC layer functions. The most important problem in terms of performance is the hidden terminal problem. To solve this problem, the solutions using a busy-tone such as BTMA, DBTMA, etc. have been proposed. In order to be able to use a busy-tone, channels using the frequency bandwidth except the frequency bandwidth of the data channel is required for the collision prevention, and a MAC layer has to be able to menage such multiple channels. In this research, we implement a module that can use a busy-tone in NS-2, implement a modified RI-BTMA by applying the implemented module, and verify its performance.

• Animal Bioscience
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• v.34 no.4
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• pp.734-742
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• 2021

Objective: The present study aimed to investigate the occurrence and species of coagulase-positive staphylococci (CoPS) and coagulase-negative staphylococci (CoNS) in retail pork meat samples collected during nationwide monitoring. The staphylococcal isolates were characterized for antimicrobial and zinc chloride resistance and enterotoxigenic potential. Methods: A total of 260 pre-packaged pork meat samples were collected from 35 retail markets in 8 provinces in Korea for isolation of staphylococci. Antimicrobial and zinc chloride resistance phenotypes, and genes associated with the resistance phenotypes were determined on the isolates. Furthermore, the presence and distribution of 19 staphylococcal enterotoxin (SE) genes and enterotoxin-like genes among the pork-associated staphylococci were determined by multiplex polymerase chain reaction-based assays using the specific primer sets. Results: A total of 29 staphylococcal strains (29/260, 11.1%) were isolated from samples of retail pork meat, 24 (83%) of which were CoNS. The four CoNS species identified were S. saprophyticus (n = 16, 55%), S. sciuri (n = 3, 10%), S. warneri (n = 3, 10%), and S. epidermidis (n = 2, 7%). Among the 29 isolates, four methicillin-resistant CoNS (MR-CoNS; three S. sciuri and one S. epidermidis) and one methicillin-resistant CoPS (MR-CoPS; one S. aureus) were identified. In addition, a relatively high level of tetracycline (TET) resistance (52%) was confirmed in CoNS, along with a predominant distribution of tet(K). The most prevalent SEs were sep (45%), and sen (28%), which were carried by 81% of S. saprophyticus. Conclusion: These findings suggest that CoNS, especially S. saprophyticus strains, in raw pork meat could be a potential risk factor for staphylococcal food poisoning (SFP), and therefore, requires further investigation to elucidate the role of SEls in SFP and virulence of the pathogen. Our results also suggest that CoNS from raw pork meat may act as a source for transmission of antimicrobial resistance genes such as staphylococcal cassette chromosome mec and tet(K).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.174-180
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• 2008

The pulsed amplifier which switches the main supply voltage of RF amplifier according to input pulse signal has good efficiency and low noise level between pulses. And it has simple structure because it doesn't need a pulse modulator at input port. The pulsed amplifier using the conventional switching circuit has slow fall time compared to rise time. We proposed the novel switching circuit for improving the fall time of pulsed amplifier The proposed switching circuit is implemented by replacing FET of conventional circuit with BJT. As a result of appling this circuit to RF pulsed amplifier, the rise and fall time are 5.7 ns and 21.9 ns at 27 dBm output power, respectively.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.360-365
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• 2019

A polyvinylidene fluoride (PVDF)-based film speaker is successfully fabricated with enhanced bass sound by incorporating buckled nanospring carbon nanotubes (NS-CNTs) as fillers. Various concentrations up to 1-7 wt% of uniformly dispersed buckled NS-CNTs are loaded to increase the beta (β)-phase fraction, crystallinity, and dielectric constant of the speaker, and this results in the bass part enhancement of about 19 dB full scale (dBFS) at 7 wt% filler loading of the piezoelectric film speaker.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.510-512
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• 2010

A series of thiobarbituric acid derivatives were constructed and evaluated for inhibitory activity on hepatitis C virus NS5B polymerase. In biochemical assays using purified viral polymerase and RNA template, the $IC_{50}$ value was improved to 0.41 ${\mu}M$ from the original compound's 1.7 ${\mu}M$ value. In HCV sub genomic replicon assay, the $EC_{50}$ value was improved to 3.7 ${\mu}M$ from the original compound's 12.3 ${\mu}M$ value. $CC_{50}$ was higher than 77 ${\mu}M$ for all compounds tested, suggesting that they are useful candidates for anti-HCV therapy.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.232-238
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• 2017

Objective : An apparent increase of use of drugs affecting hemostasis in our neurosurgical department since the 1990s has encouraged us to investigate whether these drugs influence the clinical course and results of surgery for chronic subdural hematoma (CSDH). Methods : This retrospective analysis included 178 patients admitted for CSDH from 2007 to 2011 who were divided into two groups : on drugs affecting hemostasis (40; 22%) and no bleeding disorders (138; 78%). Medications in the first group included oral anticoagulants (33; 82.5%), antiplatelets (5; 12.5%) and low molecular weight heparins (2; 5%). Results : The patients on drugs affecting hemostasis were older ($74.3{\pm}7.4$ vs. $68.4{\pm}14.8$; p-value 0.01) and the group without bleeding disorders had more head trauma history (61% vs. 38%, p-value 0.01). The groups did not differ in bilateral hematoma rates (25% vs. 20%, p-value=NS). At diagnosis, mean hematoma thickness was lower in patients on drugs affecting hemostasis ($18.7{\pm}7.4mm$ vs. $21.9{\pm}7.9mm$, p-value<0.01). Average stay of hospital was 1 day longer in patients on drugs affecting hemostasis ($11.7{\pm}4.1$ vs.$10.9{\pm}5.3$, p-value=NS) and was related to the necessity of bleeding disorder reversal. Mean neurological status at presentation was similar between the groups (p-value=NS) as was the likelihood of hematoma recurrence (p-value=NS). Glasgow Outcome Scale results were comparable. Conclusion : Patients on drugs affecting hemostasis are less often aware of a head trauma history, possibly suggesting a higher CSDH risk after minor trauma in this group. In these patients, smaller hematomas are symptomatic, probably due to faster hematoma formation. Drugs affecting hemostasis do not affect treatment results.

• The KIPS Transactions:PartA
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• v.14A no.4
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• pp.203-208
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• 2007

This paper proposes a $64{\times}64$ Modified Booth multiplier using CMOS multi-valued logic circuits. The multiplier based on the radix-4 algorithm is designed with current mode CMOS quaternary logic circuits. Designed multiplier is reduced the transistor count by 64.4% compared with the voltage mode binary multiplier. The multiplier is designed with Samsung $0.35{\mu}m$ standard CMOS process at a 3.3V supply voltage and unit current $5{\mu}m$. The validity and effectiveness are verified through the HSPICE simulation. The voltage mode binary multiplier is achieved the occupied area of $7.5{\times}9.4mm^2$, the maximum propagation delay time of 9.8ns and the average power consumption of 45.2mW. This multiplier is achieved the maximum propagation delay time of 11.9ns and the average power consumption of 49.7mW. The designed multiplier is reduced the occupied area by 42.5% compared with the voltage mode binary multiplier.

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1877-1883
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• 1999

Synchronization of the clock at the ATM receiving terminal is studied. The technique analyzed here has been adapted by ITU-T as the standard for ATM timing recovery. This paper presents analysis of SRTS method itself and jitter in SRTS. The power pectrum and rms amplitude of SRTS jitter are calculated. The calculated average rms value for T1 1.544MHz source signal is 32.63ns and 0.15ns for E4 139.264MHz signal.