• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.35-41
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• 2014

Microbes have been used extensively in various fields of researches and industries but has not been used widely for microfluidic biosensor applications because it is difficult to immobilize properly to a small space. Therefore, we developed a microbial immobilization method for microfluidic devices using single-walled nanotubes and dielectrophoretic force. Single-walled nanotubes and Escherichia coli were aligned between two cantilever electrodes by a positive dielectrophoretic force resulting in a film of single-walled nanotubes with attached Escherichia coli. The optimal condition of film formation without a cell lysis was investigated. Diameter of single-walled nanotubes and electric field (intensity and duration of application) had an effect on the cell viability. On the other hand, the cell concentration of the suspension did not affect the cell viability. Paraoxon was detected using single-walled nanotubes film with attached Escherichia coli that expressed organophosphorus hydrolase. This film which is suspended from the substrate showed faster response time than sensors that are not suspended from the substrate.

• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.38-38
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• 2002

Whole-cell recordings from adult rat sympathetic neurons demonstrate that calcium current is comprised of at least three types, N, L '||'&'||' R. We are using cell-attached patch recording to identify the single calcium channels that underlie these macroscopic currents. Single channels were resolved the presence of 100 mM Ba$\^$2＋/ and l${\mu}$M BayK 8644 over the voltage range -40 to $\^$＋/50 mV.(omitted)

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.446-455
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• 2014

This study revealed the results related to the functionality of outdoor wear required when man and women in their 30s to 50s engage in outdoor activities. Based on the results of the survey, we proposed composition draft for a smart outdoor jacket with main functions of GPS device and light-emitting device using solar cell and EL. Absorption and release of sweat, functionality regarding rain and wind, and lightweightness, etc. from material functionalities of outdoor wear were found to be important. From function required in clothing for outdoor activity, location tracking, night glow, and lighting functions were found to be most important. For results investigating the necessity of the jacket's location tracking function and lighting function using solar cell, high scores of 3.9~4.0 were given. Purchase intentions for smart outdoor jacket with location tracking and lighting functions devised by this study were fairly positive and most responses indicated that the appropriate purchase price was between 200,000 to 300,000 won while possible problems of this smart outdoor jacket were listed in the order of washing inconvenience, high price, device weight, and discomfort in movement. The draft proposal to integrate with wearable devices for smart outdoor jacket prototype is as follows: Solar cell has been attached to the upper arm but placed inside a transparent pocket which has been detachable for washing convenience while the solar cell and controller have been integrated into a single unit. Using frequent movement exhibited by the arms, EL has been attached along the center line of the raglan sleeve for easy spotting when used as an emergency signal or for night lighting function during outdoor activity. GPS has been attached on the left sleeve so that the person can bend the left arm inward and operate the GPS screen with the right hand while walking or running outdoors.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.154-157
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• 2002

A cyto-indentation technique was used to obtain the biomechanical compressive compliance property of an chondrocyte cell attached to glass surface, which was tried to generate joint cartilage by tissue engineering. Piezo-transducer system and dual photo-diode system were used to conduct mechanical indentation through displacement-controlled testing and the measurement of corresponding cell reaction force. The Poisson's ratio of 0.37 was quoted from other report. The compressive compliance of chondrocyte, that was determined by elastic contact theory, was 1.38${\pm}$0.057 kPa. This value is 30% higher than that of MG63 osteoblast-like cell. The cyto-indentation technique employed in this study is so precise that it can quantify the biomechanical property of single cell.

• Microbiology and Biotechnology Letters
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• v.21 no.2
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• pp.176-180
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• 1993

Survival and heat resistance of Listeria monocytogenes Scott A in various nutritional environments and cell type on stainless steel were determined. Viable cell of L. monocytogenes Scott A was most rapidly decreased in phosphate buffer among various media such as NSM (30 g TSB/1 l D.W.), LNM (2 g TSB/1 l D.W.) and phosphate buffer (pH=7) during incubation at 21 and 35C but survived for 15 days at 21C. Vegetative and starved L. monocytogenes Scott A were survived after heat treatment for 5 min at 65C while not detected at 72C.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.109.2-109.2
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• 2011

A photovoltaic system is getting the spotlight for a environment-friendly energy source. But its location is limited because a lot of land is necessary for photovoltaic arrays. Nevertheless, its dissemination is rapidly increasing more than 40 % every year and exceeded about 400 MW in 2009. The radical growth of a photovoltaic system aggravated a lack of sites, so that forests and farmland were destroyed. It is demanded to make use of a vacant lot or little piece of land for the way to solve the lack of sites and improve the location requirements for a photovoltaic system. General photovoltaic arrays are consist of a single layer structure and needs enough separation distances to maximize the amount of solar radiation and to eliminate influences by the shadow of other arrays. So that a large amount of land is required for the site. The solar cell arrays with long separation distances can not be placed in a small vacant lot and its site application efficiency is low. This study optimized photovoltaic arrays as multilayered structure with movable sleeves for the efficient photovoltaic in a small site. The existing photovoltaic arrays with a single layer structure were fixed or tracking systems. In this experimental equipment, photovoltaic arrays attached to the multilayers have rectilinear movement and rotary motion using sleeves. Therefore, shadow influences were removed and the generation capacity was improved. On the simulation result, generation increased by about 30% in the same site considering shadow influences and so on.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.25-28
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• 2003

Ion channel inhibitors are widely used for pharmacological discrimination between the different channel types as well as for determination of their functional role. In the present study, we tested the hypothesis that 4-aminopyridine (4-AP) could affect the large conductance $Ca^{2+}$-activated $K^+$ channel ($BK_{Ca}$) currents using perforated-patch or cell-attached configuration of patch-clamp technique in the rabbit pulmonary arterial smooth muscle. Application of 4-AP reversibly inhibited the spontaneous transient outward currents (STOCs). The reversal potential and the sensitivity to charybdotoxin indicated that the STOCs were due to the activation of $BK_{Ca}$. The $BK_{Ca}$ currents were recorded in single channel resolution under the cell-attached mode of patch-clamp technique for minimal perturbation of intracellular environment. Application of 4-AP also inhibited the single $BK_{Ca}$ currents reversibly and dose-dependently. The membrane potential of rabbit pulmonary arterial smooth muscle cells showed spontaneous transient hyperpolarizations (STHPs), presumably due to the STOC activities, which was also inhibited by 4-AP. These results suggest that 4-AP can inhibit $BK_{Ca}$ currentsin the intact rabbit vascular smooth muscle. The use of 4-AP as a selective voltage-dependent $K^+$ (KV) channel blocker in vascular smooth muscle, therefore, must be reevaluated.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1655-1657
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• 2002

Ultra-wide bandwidth (UWB), narrow bandwidth (single frequency), and a combination of both technologies have been studied for the ultra-high frequency (UHF) partial discharge (PD) monitoring system as a detection scheme. We have experimentally compared those detection methods using a mock-up of 362 kV class single phase gas-insulated switchgear (GIS) and a stable PD source. A rolling-ball type PD cell that produces PDs of about 10 pC, is placed at one end of the GIS. An internal UHF PD sensor was attached several meters away from the PD source. The PD spectrum was measured up to 3 GHz. A useable bandwidth of more than 1 GHz was used to measure UWB signals from the PD. To simulate the narrow bandwidth scheme a bandwidth of 100 kHz centered at several different frequencies was used.

• Korean Journal of Microbiology
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• v.17 no.1
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• pp.1-15
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• 1979

Mycoplasma pneumoniae strain CL-s attached to broth-covered surfaces was examined sequentially during growth from single cells for morphologic and ultrastructural changes using several different electron microscopic techniques. Changes in morphology revealed both round and spindle shapes and observation of cell transitions suggested some type of morphological cycle. The round to-ovoid cells observed in the early stages of growth appeared to be viable, and morphologically and ultrastructurally different from the spherical fors which were produced during the latter stage of growth. The spindle segments were detected appeared to be structurally the same as the terminal cored structure seen in thin sections and may be a growing point or an attachment site of the cell. A tubular structure was observed in the core of the terminal structure and a microtubule-like element appeared to bridge between some spindle segments. A matrix sunstance was observed around single cells as well in the intercellular space of the colonies prepared by critical point metrical triple-layered cytoplasmic mermbranes, surfaces, of which appeared to be structurally different each other, were observed in young cells, whereas symmetrical and thicker membranes were seen in older cells. Small bodies were found in 4d or older cultures and did not appear to contain any internal structures or an easily detectable unit membrane.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.2
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• pp.73-77
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• 2008

Recent studies have documented that testosterone relaxes several smooth muscles by modulating $K^+$ channel activities. Smooth muscles of seminal vesicles playa fundamental role in ejaculation, which might involve testosterone. This study was aimed to assess the role of testosterone in seminal vesicular motility by studying its effects on contractile agents and on the ion channels of single vesicular myocytes in a rabbit model. The contractile responses of circular smooth muscle strips of rabbit seminal vesicles to norepinephrine ($10{\mu}M$), a high concentration of KCI (70 mM), and testosterone ($10{\mu}M$) were observed. Single vesicular myocytes of rabbit were isolated using proteolytic enzymes including collagenase and papain. Inside-out, attached, and whole-cell configurations were examined using the patch clamp technique. The applications of $10{\mu}M$ norepinephrine or 70 mM KCl induced tonic contractions, and $10{\mu}M$ testosterone (pharmacological concentration) evoked dose-dependent relaxations of these precontracted strips. Various $K^+$ channel blockers, such as tetraethylammonium (TEA; $10{\mu}M$), iberiotoxin ($0.1{\mu}M$), 4-aminopyridine (4-AP, $10{\mu}M$), or glibenclamide ($10{\mu}M$) rarely affected these relaxations. Single channel data (of inside-out and attached configurations) of BK channel activity were also hardly affected by testosterone ($10{\mu}M$). On the other hand, however, testosterone reduced L-type $Ca^{2+}$ currents significantly, and found to induce acute relaxation of seminal vesicular smooth muscle and this was mediated, at least in part, by $Ca^{2+}$ current inhibition in rabbit.