Earticle

For oligonucleotide microarray, target gene is generally amplified by polymerase chain reaction (PCR) and purified. In the present work, we suggest fast and non-labeling direct 16S rRNA detection of pathogenic bacteria without amplification and purification of target gene. Because 16S rRNA has many copies in all living bacteria, we successfully used 16S rRNA as a target for microarray. For simple and fast direct detection of pathogens, we used our previously constructed 16S rDNA-based oligonucleotide microarray detection system. The bacterial total RNAs from cell lysis were hybridized to a specific 16S rRNA probes and detected using fluorescent-labeled detector probe without labeling reactions of target RNAs. We found that hybridization specificity and sensitivity were enhanced using the fragmented RNAs. We also investigated the limit of detection (LOD) using Vibrio vulnificus.

240 GHz 대역의 캐리어 주파수를 이용하여 1.485 Gbps 비디오 전송 시스템을 설계 및 시뮬레이션 하였다. 송수신기는 Schottky Barrier 다이오드 기반의 Sub-harmonic 믹서를 이용하였으며 특히, 수신기는 Heterodyne 및 Direct Detection 두 가지 방식을 적용하여 각각의 성능을 시뮬레이션 하였다. 변조방식은 ASK이며, 수신기에서는 Envelop 검출 방식을 사용하였다. 송신기 시뮬레이션 결과 Sub-harmonic 믹서의 LO 전력 7 dBm(5 mW)에서 IF 입력 전력 -3 dBm(0.5 mW)일 때 RF 출력 전력은 -11.4 dBm(73 μW)이었으며, SSB(Single Side Band) Conversion Loss는 8.4 dB이다. VDI사의 상용모델 WR3.4SHM(220∼325 GHz)의 240 GHz에서의 Conversion loss 8.0 dB(SSB)와 근접한 결과를 얻었다. 1.485 Gbps NRZ 신호전송 시뮬레이션 결과 전송신호와 동일한 수신 파형을 얻었다.

n this paper, a 1.485 Gbps video signal transmission system using the carrier frequency of 240 GHz band was designed and simulated. The sub-harmonic mixer based on Schottky barrier diode was simulated in the transmitter and receiver. Both of heterodyne and direct detection receivers were simulated for each performance analysis. The ASK modulation was used in the transmitter and the envelop detection method was used in the receiver. The transmitter simulation results showed that the RF output power was -11.4 dBm(73 μW), when the IF input power was -3 dBm(0.5 mW) at the LO power of 7 dBm(5 mW) in sub-harmonic mixer, which corresponds to SSB(Single Side Band) conversion loss of 8.4 dB. This value is similar to the conversion loss of 8.0 dB(SSB) of VDI's commercial model WR3.4SHM(220∼325 GHz) at 240 GHz. The combined transmitter and receiver simulation results showed that the recovered signal waveforms were in good agreement to the transmitted 1.485 Gbps NRZ signal.

Optical code division multiple access system (OCDMA) has been important with increasing demands of high capacity and speed for communication in optical networks. Due to OCDMA technique high efficiency is achieved, hence fiber bandwidth is fully used .In this paper we will focus on DCS (Dynamic cyclic shift) code with their different detection technique using optiwave system design tool. Due to this codes we will eliminated MAI (multiple access interference) and improve BER (bit error rate) , PIIN( Phase induced intensity noise) and make orthogonality between users in the system .We will use two different detection technique i.e Direct detection technique and AND subtraction detection technique to implement the codes with different parameters. In this paper, the study of different parameters is based on conference a paper that is mainly demonstrated on an experiment to Enhancement a performance of DCS (Dynamic cyclic shift) code with there different parameter of OCDMA using optiwave system design tool.

This research describes a simple method for direct detection of glycoproteins after affinity-capturing (or enrichment) on the plate using a combination of self-assembled monolayers (SAMs) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI). The terminal hydroxyl groups of the SAMs were activated by N,N‘-disuccinimidyl carbonate (DSC), followed by conjugation with aminophenylboronic acid (APB). The formed APB-functionalized self-assembled monolayers for MALDI (SAMDI) plates were successfully applied to the affinity-capturing of a glycoprotein from the mixture containing non-glycoproteins. The method developed in this work would provide an efficient and convenient analysis approach to proteomics.

This paper presents Long Reach Orthogonal frequency Division multiplexing Wavelength Division Multiplexing (OFDM-WDM) system capable of delivering downstream 40 Gbit/s data. The optical source for downstream data is CW Laser at central office. We use four OFDM transmitter at central office for the 40-Gb/s downstream transmission .We have used direct detection technique for OFDM and did analysis of OFDM WDM using direct detection technique for without compensation and with compensation. We extend the maximum reach of this WDM PON to be 96 km by using Erbium-doped fiber amplifiers at the RN. Bit error rate was measured and constellation diagram observed to demonstrate the proposed scheme. In this paper Long reach and large data service aspects of a OFDM WDM is presented. The results show that the error-free transmission can be achieved for all WDM channels with sufficient power margins.

This study was carried out to develop a small-sized biosensor based on surface plasmon resonance (SPR) for the rapid identification of insecticide residues for food safety. The SPR biosensor module consists of a single 770 nm-light emitting diodes (LED) light source, several optical lenses for transferring light, a hemisphere sensor chip, photo detector, A/D converter, power source, and software for signal processing using a computer. Except for the computer, the size and weight of the sensor module are 150 (L)×70 (W)×120 (H) mm and 828 g, respectively. Validation and application procedures were designed to assess refractive index analysis, affinity properties, sensitivity, linearity, limits of detection, and robustness which includes an analysis of baseline stability and reproducibility of ligand immobilization using carbamate (carbofuran and carbaryl) and organophosphate (cadusafos, ethoprofos, and chlorpyrifos) insecticide residues. With direct binding analysis, insecticide residues were detected at less than the minimum 0.01 ppm and analyzed in less than 100 sec with a good linear relationship. Based on these results, we find that the binding interaction with active target groups in enzymes using the miniaturized SPR biosensor could detect low concentrations which satisfy the maximum residue limits for pesticide tolerance in Korea, Japan, and the USA.

Saliency detection is an important research topic in computer vision. The traditional methods compute image saliency map, then salient segmentation is based on the corresponding saliency map. Unfortunately, overall performance of this method is poor due to the reason of losing some fine details and spatial information within image. This paper presents a new framework to overcome the drawback, named FDSRDS(Framework for Directly Salient Region Detection and Segmentation based on graph methods). Under FDSRSD, firstly, we get the foreground image by segmenting the original image via our extended grabcut algorithm. Mostly, the saliency region is within the foreground part. Secondly, we segment the foreground image into regions by means of graph based segmentation and nearest neighbor graph . Thirdly, we use relative weber's luminance rules to calculate every region’s luminance. Finally, we get the maximum luminance region which is the saliency region. Under FDSRSD framework, algorithms we proposed capture fine details and spatial relationships in saliency computation. We demonstrate impressive results by evaluating our method with other five state-of-the-art methods on the publicly available data set.

관상심장질환 바이오마커의 하나인 CRP를 batch형 수정진동자 면역센서에 의하여 다음과 같이 분석하였다. 센서시스템의 작동은 직접결합방식에 의하여 행하였으며 CRP에 대한 항체의 최적 고정화농도는 50 μg/ml이었다. 시스템의 반응완충용액으로 0.1 M 인산완충용액 (pH 7.0)을 사용하였고 시스템 작동은 baseline 안정화, 시료첨가 및 측정, 10 mM NaOH에 의한 센서 칩 재생의 순으로 행하였다. 이중로그척도로 표시하였을 때 0.27-106.00 nM 범위의 쥐 유래 CRP에 대하여 센서반응과 직선상의 관계를 이루었으며 센서의 검출한계는 0.53 nM이었고 재사용성도 양호하였다.

A prognostic indicator of coronary heart disease, C-reactive protein, was tried to be determined by a batch-type quartz crystal microbalance immunosensor. The sensor was operated by direct-binding mode and the optimum concentration for the corresponding antibody for immobilization was 50 μg/ml. The reaction buffer for the system was 0.1 M sodium phosphate (pH 7.0) and system operation was performed in the order of baseline stabilization, analyte addition and measurement, and regeneration of the sensor chip with 10 mM NaOH. When plotted in double-logarithmic scale, the sensor showed a linear detection range of 0.27-106.00 nM for rat C-reactive protein with the limit of detection of 0.53 nM. It also showed a good reusability.

Ephedrine (EP)은 교감신경 흥분성 아민으로 다수의 약물, 한약, 건강보조제 등에서 발견된다. EP는 pseudoephedrine (PSE)의 부분입체 이성질체로 두 화합물 모두 methamphetamine (ME)의 불법합성 에 사용되어지며 특히 EP는 체중감량 및 경기력 향상을 위하여 오용 또는 남용되어지는 중요한 자극제 이다. EP에 대한 빠르고 용이한 확인 및 반정량 방법으로 TLC상 직접반응(co-spot, in situ)법을 예비적 으로 평가하였다. EP와 3종류의 유도체화 시약(9-fluorenylmethyl chloroformate (FMOC-Cl), dansyl chloride (Dansyl-Cl) 및 dabsyl chloride (Dabsyl-Cl))을 각각 보조용매인 N,N-dimethylformamide (DMF)의 존재(1 μL per spot)하에서 미사용 시와 비교 및 검출한계(Limit of Detection, LOD, 2 μL per spot, mg/mL)를 결정하였다. 또한 TLC이미지를 농도계(densitometric) 이미지분석 프로그램으로 분석하여 재현성 및 상관관 계를 평가하였다. EP의 검출한계농도는 DMF의 존재 하에서 FMOC-Cl과(10분간 상온에서 노출하여 반 응) Dansyl-Cl 사용 시(70 oC에서 반응 spots들을 유리판으로 덮은 상태에서 반응)에 각각 0.01, 0.05 mg/ mL로 DMF를 사용하지 않은 경우보다 5 ~ 10배의 증강을 보였고, Dabsyl-Cl의 경우 약 100배의 증강이 관찰되었다. 이는 DMF가 유도체 형성 시 전이상태에서 수소결합을 통한 이탈기(-Cl)의 이탈촉진과 생성 물(HCl)의 안정화에 따른 용매효과로 사료된다. FMOC-Cl의 사용 시 유도체화 반응의 재현성(RSD, 평균 치, %)은 1.70 ~ 3.48%였으나 Dansyl-Cl의 경우에는 2.48 ~ 8.10%로 변동이 심하였다. EP의 농도에 대한 생성 유도체 면적과의 상관관계(linearity, R2) 평가에서는 좁은 EP의 농도구간(0.01 ~ 0.25 mg/mL)에 서 FMOC-Cl사용 시 그리고 Dabsyl-Cl (EP, 0.01 ~ 0.5 mg/mL)사용에서 0.98 ~ 0.99로 비교적 양호한 상 관성을 보였다. 현재의 방법이 EP에 대한 동정 및 반정량적인 분석을 위한 방법으로서의 유효성을 보이기 위해서는 반응의 재현성 증가시키기 위한 추가적인 실험결과가 요구된다.

Ephedrine (EP) is a sympathomimetic amine and found in many pharmaceutical preparation, Chinese crude drugs and nutritional supplements. EP is a diastereomer of pseudoephedrine (PSE) and both have been used for the illegal production of methamphetamine (ME). Also EP is an important stimulant to be misused and abused for weight loss and performance enhancement. The rapid and easy identification and semi-quantitative analysis of EP using TLC co-spot method was performed as a preliminary step. A direct reaction (in situ, co-spot) of EP with three derivatizing reagents (FMOC-Cl, Dansyl-Cl or Dabsyl-Cl) along with/without cosolvent N,N-dimethylformamide (DMF) has been tested to determine the LOD of EP. Also the resultant TLC images of generated EP derivatives were analyzed with densitometric image analysis programs to test the repeatability and linearity of derivatization method. When the reagents FMOC-Cl (reaction spots at room temperature for 10 min.) and Dansyl-Cl (reaction spots covered with glass plate while heated at 70 oC for 10 min.) were reacted with EP along with co-solvent DMF, the LODs (Limits of detection, 2 μL/spot, mg/mL) of EP was improved about 5 and 10 times (0.01 ~ 0.05), respectively. But about 100 times of improvement was identified for Dabsyl-Cl. This can be explained by dipolar aprotic solvent’s effects through forming hydrogen bonds with the leaving group (−Cl) for faster elimination and HCl by-product to form stable structure within the transition state. The RSD value (average, %) to test the repeatability was in the range of 1.70 ~ 3.48% when FMOCCl used. A wider RSD value range of 2.48 ~ 8.10% was found with Dansyl-Cl. In the test of the co-relationship (linearity, R2) of the derivatization reaction at a narrow concentration range (0.01 ~ 0.25 mg/mL) of EP with FMOCCl, and with Dabsyl-Cl (EP, 0.01 ~ 0.5 mg/mL) a relatively good correlation was shown to be in the range of 0.98 ~ 0.99 between the areas of spots of generated derivatives and concentration of EP. To validate the current TLC method to be used at the scene or the forensic lab. to determine the LOD of EP and for a semiquantitative determination of EP, the higher reaction repeatability of a derivatization reaction at various concentration of EP should be shown and additional TLC test results are required.

W-대역 원격탐사용 라디오미터 구현을 위하여 direct detection 방식의 구조를 가지는 수신기를 설계하였으며, 통신 또는 레이다 수신기 구조와 다르게 저 잡음이면서 60 dB 이상의 고이득을 가지도록 제작하였다. 라디오미터 수신기는 W-대역에서 동작하는 4단의 고이득 저잡음 증폭기와 대역폭 필터, square law detector로 구성되었으며, 제작된 연구 결과를 제시하였다. 개발된 direct detection 수신기는 94 GHz의 입력 주파수와 약 4 GHz의 대역폭, 그리고 56 dB 이득과 입력신호가 -20 dBm 경우 적분기 출력단에서 4,500 mV/mW의 감도를 보여주고 있다.

For the W-band remote sensing radiometer, direct detection type radiometer receiver is designed. The receiver should be low noise and high gain of 60 dB unlike communication and radar receiver. The W-band radiometer consist of 4-stage low noise, high gain amplifier, band pass filter and square law detector. The developed direct detection receiver show 4 GHz bandwidth, 56 dB gain, and 4,500 mV/mW voltage sensitivity at integrator output port for -20 dBm input power at 94 GHz.

A microfluidic paper-based analytical device (µPAD) is proposed for the selective detection of ammonia in water by using the modified Berthelot reagent and a fluidic channel consisting of hollow paper. The modified Berthelot reagents were uniformly dispersed in cyclohexane and then immobilized in a detection zone of the µPAD. The loading position of the reagents and the type of a sample flow channel were optimized to achieve a sensitive ammonia detection within a short analytical time. The NH₃ µPAD exhibits a linear colorimetric response to the concentration of ammonia dissolved in water in the range of 1-100 mg L^-1, and its limit-of-detection is 1.75 mg L^-1. In addition, the colorimetric response was not influenced by the addition of 100 mg L^-1 nitrogen containing compounds (sodium nitrate, sodium nitrite, uric acid, hydroxylamine, butylamine, diethylamine) or inorganic salts (NaCl, Na₂HPO₄), presenting the enough selectivity in the detection of water-dissolved ammonia against possible interferents.

In this study, an immuno-magnetic bead (IMB)-based assay was developed to simultaneously detect Escherichia coli, Staphylococcus aureus, and Salmonella spp. and was tested in four animal-derived foods: beef, ham, egg, and ricotta cheese. The IMB-based assay exhibited good specificity by binding to five E. coli serotypes [capture efficiency (CE) average (avg.) 90.4%], five S. aureus strains (CE avg. 91.4%), and five Salmonella serotypes (CE avg. 95.4%) but not binding to non-target bacteria (CE<10%). Furthermore, the assay detected all three pathogens with a detection limit of 10 CFU/g without the need for enrichment or additional platforms. Since the results demonstrated that the IMB-based assay can effectively separate and enrich target bacteria from a variety of animal-derived food matrixes, the assay exhibits good specificity for potential use in providing rapid, immunological, presumptive identification of pathogenic bacteria.

We have successfully applied the nested PCR to detect Cylindrocarpon destructans, a major pathogen causing root rot disease from ginseng seedlings in our former study. The PCR assay, in this study, was used to detect the pathogen from soils. The nested PCR using internal transcribed spacer (ITS) 1, 4 primer set and Dest 1, 4 primer set maintained the specificity in soils containing various microorganisms. For a soil DNA extraction method targeting chlamydospores, when several cell wall disrupting methods were tested, the combination of lyophilization and grinding with glass beads, which broke almost all the chlamydospores, was the strongest. The DNA extraction method which was completed based on the above was simple and time-saving because of exclusion of unnecessary stages, and efficient to apply in soils. As three ginseng fields whose histories were known were analyzed, the PCR assay resulted as our expectation derived from the field information. The direct PCR method will be utilized as a reliable and rapid tool for detecting and monitoring C. destructans in ginseng fields.

We have established a SYBR Green-based realtime PCR method using AnyDirect solution, which enhances PCR from whole blood, for direct amplification of the virA gene of Shigella flexneri and the invA gene of Salmonella typhimurium from human feces without prior DNA purification. When we compared the efficiency of conventional or realtime PCR amplification of the virA and invA genes from the supernatant of boiled feces supplemented with S. flexneri and S. typhimurium in the presence or absence of AnyDirect solution, amplification products were detected only in reactions to which AnyDirect solution had been added. The detection limit of real-time PCR was $1{\times}10^4\;CFU/g$ feces for S. flexneri and $2{\times}10^4\;CFU/g$ feces for S. typhimurium; this sensitivity level was comparable to other studies. Our real-time PCR assay with AnyDirect solution is simple, rapid, sensitive, and specific, and allows simultaneous detection of S. flexneri and S. typhimurium directly from fecal samples without prior DNA purification.

Background/Aims: Direct sequencing is the gold standard for the detection of drug-resistance mutations in hepatitis B virus (HBV); however, this procedure is time-consuming, laborintensive, and difficult to adapt to high-throughput screening. In this study, we aimed to develop a dendron-modified DNA microarray for the detection of genotypic resistance mutations and evaluate its efficiency. Methods: The specificity, sensitivity, and selectivity of dendron-modified slides for the detection of representative drug-resistance mutations were evaluated and compared to those of conventional slides. The diagnostic accuracy was validated using sera obtained from 13 patients who developed viral breakthrough during lamivudine, adefovir, or entecavir therapy and compared with the accuracy of restriction fragment mass polymorphism and direct sequencing data. Results: The dendron-modified slides significantly outperformed the conventional microarray slides and were able to detect HBV DNA at a very low level (1 copy/?L). Notably, HBV mutants could be detected in the chronic hepatitis B patient sera without virus purification. The validation of our data revealed that this technique is fully compatible with sequencing data of drug-resistant HBV. Conclusions: We developed a novel diagnostic technique for the simultaneous detection of several drug-resistance mutations using a dendron-modified DNA microarray. This technique can be directly applied to sera from chronic hepatitis B patie

Purpose: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)2-Fe2+, as a spin trap. Methods: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR. Similarly, the retina and choroid obtained at the peak of experimental autoimmune uveo-retinitis (EAU) were placed in a vial containing luminal, and chemiluminescence was counted on a Packard liquid scintillation analyzer. Results: The ESR three-line spectrum (g=2.04; aN=12.5 G) obtained was characteristic of the adduct [(MGD)2-Fe2+-NO]. The majority of this signal was eliminated by the inducible nitric oxide synthase (iNOS) specific inhibitor aminoguanidine injected inflamed retina was detected when compared with that of the non inflamed controls. The chemiluminescent activity was further increased two-fold by the addition of bicarbonate to the inflamed retina; the phenomenon is attributable only to the presence of a high steady-state concentration of peroxynitrite. Conclusions: The study shows an unequivocal presence of nitric oxide in EAU retina and choroid and the generation of peroxynitrite. High levels of these reactive nitrogen species generated in the inflamed retina and choroids are certain to cause irreversible tissue damage, especially at the susceptible sites such as photoreceptors.

A simple analytical method that allows direct monitoring of small amount of CO$_2$ in a CO$_2$ discharge tube which utilizes the optoacoustic detection technique is described. The dependence of the optoacoustic signal on the mole fraction of CO$_2$ was shown that the system responded linearly to the amount of CO$_2$ present in the miniature discharge cavity equipped with Cu electrodes. It was also found that fraction of dissociated CO$_2$ varied from 14 to 37% of the initial concentration which depended on the current and the pressure in the tube. This simple and easy detection method has proven to possess the practical advantages over the conventional systems for the study of CO$_2$ laser electrodes.

The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.