Simultaneous Detection of Dual Nucleic Acids Using a SERS-Based Lateral Flow Assay Biosensor

Wang, Xiaokun,Choi, Namhyun,Cheng, Ziyi,Ko, Juhui,Chen, Lingxin,Choo, Jaebum American Chemical Society 2017 ANALYTICAL CHEMISTRY - Vol.89 No.2

<P>A new class of surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) biosensor has been developed for the simultaneous detection of dual DNA markers. The LFA strip in this sensor was composed of two test lines and one control line. SERS nano tags labeled with detection DNA probes were used for quantitative evaluation of dual DNA markers with high sensitivity. Target DNA, associated with Kaposis sarcoma-associated herpesvirus (KSHV) and bacillary angiomatosis (BA), were tested to validate the detection capability of this SERS-based LFA strip. Characteristic peak intensities of SERS nano tags on two test lines were used for quantitative evaluations of KSHV and BA. The limits of detection for KSHV and BA, determined from our SERS-based LFA sensing platform, were estimated to be 0.043 and 0.074 pM, respectively. These values indicate approximately 10000 times higher sensitivity than previously reported values using the aggregation-based colorimetric method. We believe that this is the first report of simultaneous detection of two different DNA mixtures using a SERS-based LFA platform. This novel detection technique is also a promising multiplex DNA sensing platform for early disease diagnosis.</P>

Implementation on Intelligent Lighting Control System of Infrared Wireless

Wang Xinxin,Yun Hongli,Wang Xiaokun,Guo Jinhui 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

Based on STC microprocessor as a center of the transmitting and receiving parts, apply the interrupt systems, timers, counters integrated. Using Code-Division infrared coding, infrared receiver distinguishes the light pulse , judges and makes the corresponding control actions to complete the all infrared remote control transmitter and receiver process. Combination of the software programs, after commissioning the system can achieve multiple dimming function, such as LED lamp PWM dimming, alternating current filament lamp dimming, multiple channel switches. The system realized the function that weak power can control not only flea power but also strong power. This system has the feature of simple hardware circuit, sophisticated software capability, high cost performance. At the same time the study of intelligent lighting control system contributes to the improvement and development of the intelligent home system.

Highly sensitive detection of high-risk bacterial pathogens using SERS-based lateral flow assay strips

Wang, Rui,Kim, Kihyun,Choi, Namhyun,Wang, Xiaokun,Lee, Jiyoung,Jeon, Jun Ho,Rhie, Gi-eun,Choo, Jaebum Elsevier 2018 Sensors and actuators. B Chemical Vol.270 No.-

<P><B>Abstract</B></P> <P>Bacterial pathogens such as <I>Yersinia pestis, Francisella tularensis,</I> and <I>Bacillus anthracis</I> are classified into the highest rank of potential bioterrorism agents. Colorimetric lateral flow assay (LFA) strips are commercially available but these conventional strips have drawbacks in terms of low sensitivity and limit of quantitative analysis. Therefore, there is an urgent need for a new sensing platform to detect these pathogens in the early contamination stage. In this study, a novel surface-enhanced Raman scattering (SERS)-based LFA strip was developed for sensitive detection of bacterial pathogens. Target-specific SERS nanotags (Raman reporter-labeled gold nanoparticles) were used as an alternative to the gold nanoparticles in conventional LFA strips. Using these SERS nanotags the presence of bacteria could be identified through a simple color change in the test line. Additionally, highly sensitive and accurate quantitative analysis could be performed by monitoring the characteristic Raman peak intensity of SERS nanotags that were captured in the test line. This highly sensitive method required a short assay time (15 min) and a tiny volume of pathogen sample (40 μL). We believe that the proposed SERS-based LFA technique has great potential as a valuable tool in the early detection of specific bacterial pathogens in the field due to its excellent analytical sensitivity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report a novel SERS-based lateral flow (LF) assay for the sensitive detection of bacterial pathogens. </LI> <LI> Quantitative analysis of low-abundance target bacteria is possible using this SERS assay platform. </LI> <LI> This approach provides new insights into early detection of specific bacterial pathogens in the field. </LI> </UL> </P>

ER membrane protein complex subunit 6 (EMC6) is a novel tumor suppressor in gastric cancer

( Xiaokun Wang ),( Yan Xia ),( Chentong Xu ),( Xin Lin ),( Peng Xue ),( Shijie Zhu ),( Yun Bai ),( Yingyu Chen ) 생화학분자생물학회(구 한국생화학분자생물학회) 2017 BMB Reports Vol.50 No.8

The endoplasmic reticulum (ER) membrane protein complex subunit 6 (EMC6) is a novel human autophagy-related molecule. Here, using tissue microarray and immunohistochemistry, we report that EMC6 protein is lost or reduced in glandular cells of patients with gastric adenocarcinoma, compared to normal stomach mucosa. Overexpression of EMC6 in gastric cancer cells inhibited cell growth, migration, invasion, and induced apoptosis and cell cycle arrest at S-phase. Further investigation suggested that EMC6 overexpression in BGC823 human adenocarcinoma gastric cancer cells reduced tumorigenicity in a xenograft model, demonstrating that EMC6 has the characteristics of a tumor suppressor. This is the first study to show that EMC6 induces cell death in gastric cancer cells. The molecular mechanism of how EMC6 functions as a tumor suppressor needs to be further explored. [BMB Reports 2017; 50(8): 411-416]

Porous nano-hydroxyapatites doped into substrate for thin film composite forward osmosis membrane to show high performance

Weiwen Wang,Yue Guo,Miyu Liu,Xiaokun Song,Jihai Duan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.9

The incorporation of inorganic nanoparticles into thin film composite forward osmosis (TFC FO) membranes is an effective method to alleviate internal concentration polarization (ICP) and enhance the flux performance of the FO membrane. In this paper, synthetic hydrophilic rod-like porous nano-hydroxyapatites (PNHAs) were doped into polysulfone (PSf) casting solution to form support layer by phase inversion; further interfacial polymerization was carried out to prepare a high performance TFC FO membrane. The results showed that the incorporation of PNHAs not only improved the thickness, porosity, hydrophilicity, and connectivity of the support layer, but also enhanced the roughness of the active layer. The measured mass transfer parameters prove that these improvements were beneficial. Further FO experiments showed that when using deionized water as the feed solution and 1 mol/L NaCl as the draw solution, TFN 0.75 showed higher water flux than TFC FO membrane in both AL-FS (18.5 vs 7.16 L/m2 ·h) and AL-DS (33.26 vs 9.93 L/m2 ·h) modes. Reverse salt flux had not increased significantly. At the same time, TFN 0.75 (697 m vs 1,960 m) showed the smallest structural parameter. This study shows that PNHA is a suitable nanomaterial for mitigating the ICP effect of FO membranes.

Expression of Human FGF18 by Fusion with Oleosin in Arabidopsis thaliana Seeds

Chao Jiang,Xiaokun Li,Feng Zhai,Nuo Xu,Jing Yang,Yunpeng Wang,Libo Jin,Haiyan Li 한국식물학회 2018 Journal of Plant Biology Vol.61 No.3

Expression of recombinant human fibroblast growthfactor 18 (hFGF18) in mammalian cells and Escherichia colihas been extensively used for fundamental research andclinical applications, but they are difficult, expensive. Theexpression of recombinant proteins fused to oleosin proteinhave distinct advantages, such as safety, ease, low cost. Sowe have expressed hFGF18 fused to oleosin protein in the oilbodies of Arabidopsis thaliana (A. thaliana) and screen theproliferation effect of NIH3T3 cells. The vector of oleosinhFGF18fusion gene was constructed and transformed intowild A. thaliana. Transformed A. thaliana lines were obtainedby the floral dip method and confirmed using polymerasechain reaction (PCR). The PCR results indicated that theoleosin-hFGF18 fusion gene was integrated into the A. thaliana genome. The oil bodies expression of oleosin-hFGF18was confirmed by sodium dodecyl sulfate polyacrylamidegel electrophoresis and western blotting. The biologicalactivity showed that oil bodies expressing oleosin-hFGF18could stimulate the proliferation of NIH3T3 cells.

Design of Dual-channel Interleaved Phase-shift Full-bridge Converter

Che, Yanbo,Wang, Dianmeng,Liu, Xiaokun The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.8 No.1

A digital dual-channel interleaved phase-shift full-bridge converter is investigated in this paper, and its topology and principle are analyzed. To realize current sharing and stabilize the output voltage, a controller with current sharing loop and closed voltage loop is employed. In addition, current sharing will increase the output current fluctuation and a new digital interleaved driving technology is proposed to reduce the output current ripple. To verify the analysis, simulation and experiments are carried out, which shows the effectiveness of the proposed control strategies.

Molybdenum trioxide impregnated carbon aerogel for gaseous elemental mercury removal

Yang Ling,Xiaokun Man,Wenbo Zhang,Daolei Wang,Jiang Wu,Qizhen Liu,Mingyan Gu,Yuyu Lin,Ping He,Tao Jia 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4

A novel gaseous elemental mercury (Hg0) removal agent was successfully synthesized via impregnation method, by using molybdenum trioxide (MoO3) as the active component and carbon aerogel (CA) as the carrier. The as-prepared samples maintained a large specific surface area and excellent pore structure of the pure carbon aerogel, so that MoO3 was better dispersed to obtain enhanced Hg0 removal performance. The maximum efficiency of elemental mercury removal was about 74%, achieved by Mo/C500 sample at 300 oC, while it still had good ability (nearly 60%) in the range of 500-700 oC. The mechanism of mercury oxidation removal was also verified by DFT calculation. This work should help in developing suitable materials for thermocatalytic oxidation of elemental mercury, and also provide some theoretical basis and data support for full-scale application of heavy metal mercury pollution control in coalfired power plants.

Simultaneous immunoassays of dual prostate cancer markers using a SERS-based microdroplet channel

Gao, Rongke,Cheng, Ziyi,Wang, Xiaokun,Yu, Liandong,Guo, Zhongyi,Zhao, Gang,Choo, Jaebum Elsevier 2018 Biosensors & Bioelectronics Vol.119 No.-

<P><B>Abstract</B></P> <P>The simultaneous detection of multiple biomarkers plays an important role in the accurate diagnosis of cancer. In this study, we developed a novel, surface-enhanced Raman scattering (SERS)-based microfluidic device for the simultaneous detection of free prostate-specific antigen (f-PSA) and total PSA (t-PSA) markers. A fully automatic droplet-based microfluidic platform for the rapid and sensitive detection of f-PSA and t-PSA was designed. Magnetic immunocomplexes were aligned on one side of the channel using a permanent magnet embedded in the microfluidic device, and parent microdroplets containing magnetic immunocomplexes and supernatant solutions were split into two smaller daughter droplets at the Y-shaped junction of the channel. Then, Raman signals of sequential droplets including supernatant solutions were measured for the quantitative analysis of the PSA markers. Two parallel microfluidic channels were designed and fabricated for the simultaneous detection of f-PSA and t-PSA. Our results showed a good linear response for both PSA markers in the range from 0.05 to 100 ng mL<SUP>−1</SUP>. The limits of detection were estimated to be below 0.1 ng mL<SUP>−1</SUP> for both the f-PSA and t-PSA. This SERS-based assay in a microfluidic channel was completed in 10 min without any manual incubation and washing steps. Our method is a very promising clinical tool for PSA-based screening test of prostate cancer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report a SERS-based microfluidic device for the detection of two prostate cancer markers. </LI> <LI> Quantitative analysis of two cancer markers in the low concentration range is possible using this device. </LI> <LI> This approach provides new insights into the accurate screening test of prostate cancer. </LI> </UL> </P>

Design of Dual-channel Interleaved Phase-shift Full-bridge Converter

Yanbo Che,Dianmeng Wang,Xiaokun Liu 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

A digital dual-channel interleaved phase-shift full-bridge converter is investigated in this paper, and its topology and principle are analyzed. To realize current sharing and stabilize the output voltage, a controller with current sharing loop and closed voltage loop is employed. In addition, current sharing will increase the output current fluctuation and a new digital interleaved driving technology is proposed to reduce the output current ripple. To verify the analysis, simulation and experiments are carried out, which shows the effectiveness of the proposed control strategies.