scholarly journals Real-time broadband terahertz spectroscopic imaging by using a high-sensitivity terahertz camera

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Natsuki Kanda ◽  
Kuniaki Konishi ◽  
Natsuki Nemoto ◽  
Katsumi Midorikawa ◽  
Makoto Kuwata-Gonokami
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Imam Uddin ◽  
Tyler C. Kilburn ◽  
Sara Z. Jamal ◽  
Craig L. Duvall ◽  
John S. Penn

AbstractDiabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are potentially blinding conditions largely due to their respective neovascular components. The development of real-time in vivo molecular imaging methods, to assess levels of retinal neovascularization (NV), would greatly benefit patients afflicted with these conditions. mRNA hybridization techniques offer a potential method to image retinal NV. The success of these techniques hinges on the selection of a target mRNA whose tissue levels and spatial expression patterns correlate closely with disease burden. Using a model of oxygen-induced retinopathy (OIR), we previously observed dramatic increases in retinal endoglin that localized to neovascular structures (NV), directly correlating with levels of neovascular pathology. Based on these findings, we have investigated Endoglin mRNA as a potential marker for imaging retinal NV in OIR mice. Also of critical importance, is the application of innovative technologies capable of detecting mRNAs in living systems with high sensitivity and specificity. To detect and visualize endoglin mRNA in OIR mice, we have designed and synthesized a novel imaging probe composed of short-hairpin anti-sense (AS) endoglin RNA coupled to a fluorophore and black hole quencher (AS-Eng shRNA). This assembly allows highly sensitive fluorescence emission upon hybridization of the AS-Eng shRNA to cellular endoglin mRNA. The AS-Eng shRNA is further conjugated to a diacyl-lipid (AS-Eng shRNA–lipid referred to as probe). The lipid moiety binds to serum albumin facilitating enhanced systemic circulation of the probe. OIR mice received intraperitoneal injections of AS-Eng shRNA–lipid. Ex vivo imaging of their retinas revealed specific endoglin mRNA dependent fluorescence superimposed on neovascular structures. Room air mice receiving AS-Eng shRNA–lipid and OIR mice receiving a non-sense control probe showed little fluorescence activity. In addition, we found that cells in neovascular lesions labelled with endoglin mRNA dependent fluorescence, co-labelled with the macrophage/microglia-associated marker IBA1. Others have shown that cells expressing macrophage/microglia markers associate with retinal neovascular structures in proportion to disease burden. Hence we propose that our probe may be used to image and to estimate the levels of retinal neovascular disease in real-time in living systems.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1922
Author(s):  
Gwang Su Kim ◽  
Yumin Park ◽  
Joonchul Shin ◽  
Young Geun Song ◽  
Chong-Yun Kang

The breath gas analysis through gas phase chemical analysis draws attention in terms of non-invasive and real time monitoring. The array-type sensors are one of the diagnostic methods with high sensitivity and selectivity towards the target gases. Herein, we presented a 2 × 4 sensor array with a micro-heater and ceramic chip. The device is designed in a small size for portability, including the internal eight-channel sensor array. In2O3 NRs and WO3 NRs manufactured through the E-beam evaporator’s glancing angle method were used as sensing materials. Pt, Pd, and Au metal catalysts were decorated for each channel to enhance functionality. The sensor array was measured for the exhaled gas biomarkers CH3COCH3, NO2, and H2S to confirm the respiratory diagnostic performance. Through this operation, the theoretical detection limit was calculated as 1.48 ppb for CH3COCH3, 1.9 ppt for NO2, and 2.47 ppb for H2S. This excellent detection performance indicates that our sensor array detected the CH3COCH3, NO2, and H2S as biomarkers, applying to the breath gas analysis. Our results showed the high potential of the gas sensor array as a non-invasive diagnostic tool that enables real-time monitoring.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana-Luisa Silva ◽  
Paulina Klaudyna Powalowska ◽  
Magdalena Stolarek ◽  
Eleanor Ruth Gray ◽  
Rebecca Natalie Palmer ◽  
...  

AbstractAccurate detection of somatic variants, against a background of wild-type molecules, is essential for clinical decision making in oncology. Existing approaches, such as allele-specific real-time PCR, are typically limited to a single target gene and lack sensitivity. Alternatively, next-generation sequencing methods suffer from slow turnaround time, high costs, and are complex to implement, typically limiting them to single-site use. Here, we report a method, which we term Allele-Specific PYrophosphorolysis Reaction (ASPYRE), for high sensitivity detection of panels of somatic variants. ASPYRE has a simple workflow and is compatible with standard molecular biology reagents and real-time PCR instruments. We show that ASPYRE has single molecule sensitivity and is tolerant of DNA extracted from plasma and formalin fixed paraffin embedded (FFPE) samples. We also demonstrate two multiplex panels, including one for detection of 47 EGFR variants. ASPYRE presents an effective and accessible method that simplifies highly sensitive and multiplexed detection of somatic variants.


2014 ◽  
Vol 105 (6) ◽  
pp. 063118 ◽  
Author(s):  
Daquan Yang ◽  
Shota Kita ◽  
Feng Liang ◽  
Cheng Wang ◽  
Huiping Tian ◽  
...  

Sensors ◽  
2017 ◽  
Vol 17 (12) ◽  
pp. 2813 ◽  
Author(s):  
Raffaele Caroselli ◽  
David Martín Sánchez ◽  
Salvador Ponce Alcántara ◽  
Francisco Prats Quilez ◽  
Luis Torrijos Morán ◽  
...  

2011 ◽  
Vol 50 (4) ◽  
pp. 859-872 ◽  
Author(s):  
Valery M. Melnikov ◽  
Dusan S. Zrnić ◽  
Richard J. Doviak ◽  
Phillip B. Chilson ◽  
David B. Mechem ◽  
...  

AbstractSounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D allow observations of a variety of clouds with reflectivities as low as −25 dBZ (at a range of 10 km). The high sensitivity of the WSR-88D, its wide velocity and unambiguous range intervals, and the absence of attenuation allow accurate measurements of the reflectivity factor, Doppler velocity, and spectrum width fields in clouds to ranges of about 50 km. Fields of polarimetric variables in clouds, observed with a research polarimetric WSR-88D, demonstrate an abundance of information and help to resolve Bragg and particulate scatter. The scanning, Doppler, and polarimetric capabilities of the WSR-88D allow real-time, three-dimensional mapping of cloud processes, such as transformations of hydrometeors between liquid and ice phases. The presence of ice particles is revealed by high differential reflectivities and the lack of correlation between reflectivity and differential reflectivity in clouds in contrast to that found for rain. Pockets of high differential reflectivities are frequently observed in clouds; maximal values of differential reflectivity exceed 8 dB, far above the level observed in rain. The establishment of the WSR-88D network consisting of 157 polarimetric radars can be used to collect cloud data at any radar site, making the network a potentially powerful tool for climatic studies.


Author(s):  
Zhijia Peng ◽  
Xiaogang Lin ◽  
Weiqi Nian ◽  
Xiaodong Zheng ◽  
Jayne Wu

Early diagnosis and treatment have always been highly desired in the fight against cancer, and detection of circulating tumor DNA (ctDNA) has recently been touted as highly promising for early cancer screening. Consequently, the detection of ctDNA in liquid biopsy gains much attention in the field of tumor diagnosis and treatment, which has also attracted research interest from the industry. However, traditional gene detection technology is difficult to achieve low cost, real-time and portable measurement of ctDNA. Electroanalytical biosensors have many unique advantages such as high sensitivity, high specificity, low cost and good portability. Therefore, this review aims to discuss the latest development of biosensors for minimal-invasive, rapid, and real-time ctDNA detection. Various ctDNA sensors are reviewed with respect to their choices of receptor probes, detection strategies and figures of merit. Aiming at the portable, real-time and non-destructive characteristics of biosensors, we analyze their development in the Internet of Things, point-of-care testing, big data and big health.


2021 ◽  
Author(s):  
Mohammad Jahidur Rahman Khan ◽  
Md. Shahadat Hossain ◽  
Samshad Jahan Shumu ◽  
Md. Selim Reza ◽  
Farzana Mim ◽  
...  

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.


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