• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.979-985
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• 2001

A fluorometric detection technique for HDL (High Density Lipoprotein) and LDL (Low Density Lipoprotein) was developed for application in a fiber-optic immunosensor using a protein A Langmuir-Blodgget (LB) film. For the fluorescence immunoassay, antibodies specific to HDL or LDL were imobilied on the protein A LB film, and a fluorescence amplification method was developed to overcome their weak fluorescence. The deposition of protein A using the LB technique was monitored using a surface pressure-are $({\pi}-A)$ curve, and the antibody immobilization of the protein A LB film was experimentally verified. The immobilized antibody was used to separate only HDL and LDL from a sample, then the fluorescence of he separated HDL or LDL was amplified. The amount of LDL or HDL was measured using the developed fiber optic fluorescence detection system. The optical properties resulting from the reaction of HDL or LDL with o-phtaldialdehyde, detection range, response time, and stability of the immunoassay were all investigated. The respective detection ranges for HDL and LDL were sufficient to diagnose the risk of coronary heart disease. The amplification step increased the sensitivity, while selective separation using the immobilized antibody led to linearity in the sensor signal. The regeneration of the antibody-immobilized substrate could produce a stable and reproducible immunosensor.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.89-99
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• 1996

The purpose of this study was to develop the diagnosis techniques for sex determination of rabbit embryos at preimplantation stage. To detect male specific sequences using polymerase chain reaction, two genes functional on sex determination including SRY and ZFX/Y genes were targeted using multiple oligonucleotide primer sets. Three of them for conserved SRY gene were used for appropriate amplification pattern, and then only one primer set #3 proved to be most efficient, showing male-specific strong signal ofamplified sequences. Using this male specific bandsfrom human, cattle, pig and mouse, the gender of rabbit was determined. As an another system for sex determination system, amplified 910bp fragment from ZFX/Y was digested with several restriction endonuclease and showed gender specific restriction fragments only by Hinf I. Using two different system for sex identification of rabbit in this study, blind tests for 17 samples was conducted and showed identical results from two different methods. And then, amplification limit of PCR reaction for template DNA was estimated using various amounts of DNA for both SRY and ZFX/Y systems, resulted as 20pg and 800pg, respectively. With this results, test for gender identification of rabbit embryos were performed using SRY derived amplification system. From total 22 embryos selected for its developmental state 18 were identified as male embryos, showing significant difference from expected sex ratio 1:1. This biased sex ratio was interpreted as to have been caused by the fact, reported by the fact, reported by several researchers, that male embryos develop more rapidly and are more resistant against the in vitro manipulation than female embryos.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.70-74
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• 2007

This paper describes the development of a nano-positioning system for nanoscale science and engineering. Conventional positioning systems, which can be expensive and complicated, require the use of laser interferometers or capacitive transducers to measure nanoscale displacements of the stage. In this study, a new self-displacement sensing (SDS) nano-stage was developed using mechanical magnification of its displacement signal. The SDS nano-stage measured the displacement of its movement using a position-sensitive photodiode (PSPD), a laser source, and a hinge-connected rotating mirror plate. A beam from a laser diode was focused onto the middle of the plate with the rotating mirror. The position variation of the reflected beam from the mirror rotation was then monitored by the PSPD. Finally, the PSPD measured the amplified displacement as opposed to the actual movement of the stage via an optical lever mechanism, providing the ability to more precisely control the nanoscale stage. The displacement amplification process was modeled by structural analysis. The simulation results of the amplification ratio showed that the distance variation between the PSPD and the mirror plate as well as the length L of the mirror plate could be used as the basic design parameters for a SDS nano-stage. The PSPD was originally designed for a total travel range of 30 to 60 mm, and the SDS nano-stage amplified that range by a factor of 15 to 25. Based on these results, a SDS nano-stage was fabricated using principle of displacement amplification.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.833-837
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• 2007

In this study, we have fabricated a gain flattened erbium-doped optical fiber amplifier. Gain flattening filters were realized by the strain-induced long period fiber gratings, which are made of periodically arrayed metal wires. Using the filter of $550{\mu}m$ period, spontaneous emission amplified at C-band wavelength by a 980nm pumping laser was flattened within 1dB of gain ripple. The performance of the simultaneous multi channel amplification was measured using a fabry-perot laser diode. Amplification ratio was above 20dB. This amplifier can be applied to the long distance transmission system based on a wavelength division multiplexing for boosting an attenuated signal.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1666-1671
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• 2022

The structure of a high-power gain-flattened long wavelength band (L-band) optical amplifier was optimized, which was implemented for 64-channel wavelength division multiplexed optical signals with a channel spacing of 50 GHz. The output characteristics of this L-band amplifier were measured and analyzed. The amplifier of the optimized two-stage amplification configuration had a flattened gain of 20 dB within 1 dB deviation between 1570 and 1600 nm for -2 dBm input power condition. The noise figure under this condition was minimized to within 6 dB in the amplification bandwidth. The gain flattening was realized by considering only the characteristics of gain medium in the amplifier without using additional optical or electrical devices. The proposed amplifier consisted of two stages of amplification stages, each of which was based on the erbium-doped fiber amplifier (EDFA) structure. The erbium-doped fiber length and pumping structures in each stage of the amplifier were optimized through experiments.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.11-15
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• 2018

In this study, we deposited silver nanoparticles on the nanocone array structure which was fabricated by the UV nanoimprint process for optical signal amplification. The deposition of the silver nanoparticles was based on the evaporation behavior of the solution droplet according to wettability of surface and the deposition pattern changed from the center of the droplet to the edge depending on the difference of thermal energy. The optical property of silver nanoparticles that were deposited on imprinted nanohole patterns was simulated by the Finite difference time domain (FDTD) analysis method, and it was confirmed that energy was concentrated around the silver nanoparticle of the finally fabricated structure.

• BMB Reports
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• v.39 no.3
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• pp.247-252
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• 2006

A rapid method for the detection of Hepatitis E Virus (HEV) was developed by utilizing nano-gold labeled oligonucleotide probes, silver stain enhancement and the microarray technique. The 5'-end -$NH_2$ modified oligonucleotide probes were immobilized on the surface of the chip base as the capture probe. The detection probe was made of the 3'-end -SH modified oligonucleotide probe and nano-gold colloid. The optimal concentrations of these two probes were determined. To test the detection sensitivity and specificity of this technique, a conservative fragment of the virus RNA was amplified by the RT-PCR/PCR one step amplification. The cDNA was hybridized with the capture probes and the detection probes on microarray. The detection signal was amplified by silver stain enhancement and could be identified by naked eyes. 100 fM of amplicon could be detected out on the microarray. As the results, preparation of nano-gold was improved and faster. Development time also was shortened to 2 min. Thus, considering high efficiency, low cost, good specificity and high sensitivity, this technique is alternative for the detection of HEV.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3825-3827
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• 2012

FISH is one of the most sensitive molecular methods to detect genetic abnormalities with DNA probes. When cytogenetic studies are normal or insufficient, FISH may detect cryptic rearrangements, rare or slowly proliferative abnormal populations in non-mitotic cells. We cytogenetically evaluated 70 childhood ALL - 67.1% were found to have an abnormal karyotype. The 23 patients (32.9%) with a normal karyotype were analyzed by FISH applying two probes; TEL/AML1 and MYB which detect cryptic rearrangements of t(12;21)(p13;q22) and deletion of (6q) respectively, associated with a good prognosis. Out of 23 patients, one was positive for t(12;21)(p13;q22) (4.3%). None of our patients were positive for MYB del(6q). Two patients showed an extra signal for MYB on chromosomes other than 6 (8.6 %) indicating amplification or duplication. Findings were compared with the available literature. Our study clearly indicated the integrated FISH screening method to increase the abnormality detection rate in a narrow range. FISH is less useful for diagnostic study of patients with suspected del(6q) but it helps in detecting known cryptic rearrangements as well as identification of new abnormalities(translocation , duplication and amplification) at the gene level.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1118-1123
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• 2009

Event-specific real-time polymerase chain reaction (PCR) detection method for genetically modified (GM) maize MIR604 was developed based on integration junction sequences between the host plant genome and the integrated transgene. In this study, 2 primer pairs and probes were designed for specific amplification of 100 and 111 bp DNA fragments from the zSSIIb gene (the maize endogenous reference gene) and MIR604. The quantitative method was validated using 3 certified reference materials (CRMs) with levels of 0.1, 1, and 10% MIR604. The method was also assayed with 14 different plants and other GM maize. No amplification signal was observed in real-time PCR assays with any of the species tested other than MIR604 maize. As a result, the bias from the true value and the relative deviation for MIR604 was within the range from 0 to 9%. Precision, expressed as relative standard deviation (RSD), varied from 2.7 to 10% for MIR604. Limits of detections (LODs) of qualitative and quantitative methods were all 0.1%. These results indicated that the event-specific quantitative PCR detection system for MIR604 is accurate and useful.

• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.120-124
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• 2022

With advancements in underwater stealth technology for naval vessels, new sensor configurations for detecting targets have been attracting increased attention. Latest underwater mines adopt multiple sensor configurations that include electric field sensors to detect targets and to help acquire accurate ignition time. An underwater electric field sensor consists of a pair of electrodes, signal processing unit, and preamplifier. For detecting underwater electric fields, the preamplifier requires low-noise amplification at ultra-low frequency bands. In this paper, the specific requirements for low-noise preamplifiers are discussed along with the experimental results of various setups of matched transistors and chopper stabilized operational amplifiers. The results showed that noise characteristics at ultra-low frequency bands were affected significantly by the voltage noise density of the chopper amplifier and the number of matched transistors used for differential amplification. The fabricated preamplifier was operated within normal design parameters, which was verified by testing its gain, phase, and linearity.