http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Walter Liu (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
-
Liu, Yi-Shao,Walter, T. M.,Chang, Woo-Jin,Lim, Kwan-Seop,Yang, Liju,Lee, S. W.,Aronson, A.,Bashir, R. Royal Society of Chemistry 2007 Lab on a chip Vol.7 No.5
<P>In this paper, we present a new impedance-based method to detect viable spores by electrically detecting their germination in real time within microfluidic biochips. We used <I>Bacillus anthracis</I> Sterne spores as the model organism. During germination, the spores release polar and ionic chemicals, such as dipicolinic acid (DPA), calcium ions, phosphate ions, and amino acids, which correspondingly increase the electrical conductivity of the medium in which the spores are suspended. We first present macro-scale measurements demonstrating that the germination of spores can be electrically detected at a concentration of 10<SUP>9</SUP> spores ml<SUP>−1</SUP> in sample volumes of 5 ml, by monitoring changes in the solution conductivity. Germination was induced by introducing an optimized germinant solution consisting of 10 mM <SMALL>L</SMALL>-alanine and 2 mM inosine. We then translated these results to a micro-fluidic biochip, which was a three-layer device: one layer of polydimethylsiloxane (PDMS) with valves, a second layer of PDMS with micro-fluidic channels and chambers, and the third layer with metal electrodes deposited on a pyrex substrate. Dielectrophoresis (DEP) was used to trap and concentrate the spores at the electrodes with greater than 90% efficiency, at a solution flow rate of 0.2 μl min<SUP>−1</SUP> with concentration factors between 107–109 spores ml<SUP>−1</SUP>, from sample volumes of 1–5 μl. The spores were captured by DEP in deionized water within 1 min (total volume used ranged from 0.02 μl to 0.2 μl), and then germinant solution was introduced to the flow stream. The detection sensitivity was demonstrated to be as low as about a hundred spores in 0.1 nl, which is equivalent to a macroscale detection limit of approximately 10<SUP>9</SUP> spores ml<SUP>−1</SUP>. We believe that this is the first demonstration of this application in microfluidic and BioMEMS devices.</P> <P>Graphic Abstract</P><P>We present an impedance based electrical method to detect germination of viable spores in microfluidic devices. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b702408h'> </P>
-
-
-
Application of Terahertz Spectroscopy and Imaging in the Diagnosis of Prostate Cancer
Zhang, Ping,Zhong, Shuncong,Zhang, Junxi,Ding, Jian,Liu, Zhenxiang,Huang, Yi,Zhou, Ning,Nsengiyumva, Walter,Zhang, Tianfu Optical Society of Korea 2020 Current Optics and Photonics Vol.4 No.1
The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.
-
Application of Terahertz Spectroscopy and Imaging in the Diagnosis of Prostate Cancer
Ping Zhang,Shuncong Zhong,Junxi Zhang,Jian Ding,Zhenxiang Liu,Yi Huang,Ning Zhou,Walter Nsengiyumva,Tianfu Zhang 한국광학회 2020 Current Optics and Photonics Vol.4 No.1
The feasibility of the application of terahertz electromagnetic waves in the diagnosis of prostate cancer was examined. Four samples of incomplete cancerous prostatic paraffin-embedded tissues were examined using terahertz spectral imaging (TPI) system and the results obtained by comparing the absorption coefficient and refractive index of prostate tumor, normal prostate tissue and smooth muscle from one of the paraffin tissue masses examined were reported. Three hundred and sixty cases of absorption coefficients from one of the paraffin tissues examined were used as raw data to classify these three tissues using the Principal Component Analysis (PCA) and Least Squares Support Vector Machine (LS-SVM). An excellent classification with an accuracy of 92.22% in the prediction set was achieved. Using the distribution information of THz reflection signal intensity from sample surface and absorption coefficient of the sample, an attempt was made to use the TPI system to identify the boundaries of the different tissues involved (prostate tumors, normal and smooth muscles). The location of three identified regions in the terahertz images (frequency domain slice absorption coefficient imaging, 1.2 THz) were compared with those obtained from the histopathologic examination. The tissue tumor region had a distinctively visible color and could well be distinguished from other tissue regions in terahertz images. Results indicate that a THz spectroscopy imaging system can be efficiently used in conjunction with the proposed advanced computer-based mathematical analysis method to identify tumor regions in the paraffin tissue mass of prostate cancer.
-
Smart Bioreso rbable Polymers for Pharmaceuticals and Medical Devices
Vaishali Tawde,Sundeep Chaurasia,Saurabh Gupta,Rohan Rastogi,Ajay Kumar Dantuluri,Walter Liu,Sean Mcmahon,Dong-Won Seo 대한약학회 2022 약학회지 Vol.66 No.1
Smart bioresorbable polymers play a crucial role in pharmaceutical drug delivery and medical device applications. Among several bioresorbable polymers, poly lactic-co-glycolic acid and poly lactic acid are two common synthetic polymers used for various applications. Owing to their stimuli-sensitive behavior, they are called ‘smart polymers.’ Numerous commercial applications have demonstrated the effective use of bioresorbable polymer-based drug delivery systems for the treatment and diagnosis of several diseases and disorders. This review provides an overview of bioresorbable polymers as well as the associated commercial technologies and applications in the United States Food and Drug Administration-approved products and in drug delivery and medical devices.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
