High sensitivity non-invasive detection of calcifications deep inside biological tissue using Transmission Raman Spectroscopy

2017 ◽  
Vol 11 (1) ◽  
pp. e201600260 ◽  
Author(s):  
Adrian Ghita ◽  
Pavel Matousek ◽  
Nick Stone
The Analyst ◽  
2021 ◽  
Author(s):  
Benjamin Gardner ◽  
Pavel Matousek ◽  
Nicholas Stone

Higher contrast of subsurface Raman spectra is achievable with self-absorption corrected transmission Raman spectroscopy. (Desired signal in red, interfering matrix artefacts in blue.)


2016 ◽  
Vol 187 ◽  
pp. 329-339 ◽  
Author(s):  
Benjamin Gardner ◽  
Nicholas Stone ◽  
Pavel Matousek

Here we demonstrate for the first time the viability of characterising non-invasively the subsurface temperature of SERS nanoparticles embedded within biological tissues using spatially offset Raman spectroscopy (SORS). The proposed analytical method (T-SESORS) is applicable in general to diffusely scattering (turbid) media and features high sensitivity and high chemical selectivity. The method relies on monitoring the Stokes and anti-Stokes bands of SERS nanoparticles in depth using SORS. The approach has been conceptually demonstrated using a SORS variant, transmission Raman spectroscopy (TRS), by measuring subsurface temperatures within a slab of porcine tissue (5 mm thick). Root-mean-square errors (RMSEs) of 0.20 °C were achieved when measuring temperatures over ranges between 25 and 44 °C. This unique capability complements the array of existing, predominantly surface-based, temperature monitoring techniques. It expands on a previously demonstrated SORS temperature monitoring capability by adding extra sensitivity stemming from SERS to low concentration analytes. The technique paves the way for a wide range of applications including subsurface, chemical-specific, non-invasive temperature analysis within turbid translucent media including: the human body, subsurface monitoring of chemical (e.g. catalytic) processes in manufacture quality and process control and research. Additionally, the method opens prospects for control of thermal treatment of cancer in vivo with direct non-invasive feedback on the temperature of mediating plasmonic nanoparticles.


2008 ◽  
Vol 47 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Charlotte Eliasson ◽  
Neil A. Macleod ◽  
Linda C. Jayes ◽  
Fiona C. Clarke ◽  
Stephen V. Hammond ◽  
...  

Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.


2021 ◽  
pp. 201010582110061
Author(s):  
Raja Ezman Raja Shariff ◽  
Hafisyatul Aiza Zainal Abidin ◽  
Sazzli Kasim

Cardiac amyloidosis is a severely underdiagnosed cause of heart failure with preserved ejection fraction. We report a case of highly probable transthyretin (ATTR) cardiac amyloidosis (ATTR-CA) diagnosed through the assistance of non-invasive multimodality imaging. An 81-year-old man presented with worsening dyspnoea, reduced effort tolerance and limb swelling. Examination and bedside investigations demonstrated congestive cardiac failure. On arrival, N-terminal-pro B-type natriuretic peptide was 2400 ng/L, and high-sensitivity troponin T was 78 mmol/L. Echocardiography showed severe left and right ventricular hypertrophy, and a Doppler study revealed diastolic dysfunction. Cardiac magnetic resonance imaging revealed on non-conventional dark blood sequence an abnormal inversion time for nulling myocardium suggestive of infiltrative disease, including amyloidosis. The patient was referred for nuclear-based studies involving technetium-99m pyrophosphate which demonstrated changes highly diagnostic of ATTR-CA. Early diagnosis of ATTR-CA remains paramount due to the increasing availability of disease-modifying therapies. Current guidelines recognise the role of multimodality imaging in confidently recognising the disease without the need for histological evidence in the appropriate context, providing an alternative means of diagnosis.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Klara Retko ◽  
Maša Kavčič ◽  
Lea Legan ◽  
Polonca Ropret ◽  
Bojana Rogelj Škafar ◽  
...  

AbstractIn this study, a painted beehive panel from the collection of the Slovene Ethnographic Museum was examined with respect to its material composition with the aim to reveal the painting technique. Due to the state of degradation due to outdoor weathering (UV irradiation, rainfall, extreme temperature and humidity fluctuations), as well as past conservation interventions, the object represented a complex analytical challenge. We aimed for non-invasive techniques (FTIR in reflection mode, Raman spectroscopy and hyperspectral imaging in the range of 400–2500 nm); however, in order to explore paint layers, cross-sections were also analysed using Raman spectroscopy. FTIR spectroscopy in transmission mode and gas chromatography coupled to mass spectrometry were also used on sample fragments. Various original materials were identified such as pigments and binders. The surface coating applied during conservation interventions was also characterised. Additionally, organic compounds were found (oxalate, carboxylate), representing transformation products. The potential use of Prussian blue as a background paint layer is discussed.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3575
Author(s):  
Shenggang Wang ◽  
Yue Huang ◽  
Xiangming Guan

Thiols play vital and irreplaceable roles in the biological system. Abnormality of thiol levels has been linked with various diseases and biological disorders. Thiols are known to distribute unevenly and change dynamically in the biological system. Methods that can determine thiols’ concentration and distribution in live cells are in high demand. In the last two decades, fluorescent probes have emerged as a powerful tool for achieving that goal for the simplicity, high sensitivity, and capability of visualizing the analytes in live cells in a non-invasive way. They also enable the determination of intracellular distribution and dynamitic movement of thiols in the intact native environments. This review focuses on some of the major strategies/mechanisms being used for detecting GSH, Cys/Hcy, and other thiols in live cells via fluorescent probes, and how they are applied at the cellular and subcellular levels. The sensing mechanisms (for GSH and Cys/Hcy) and bio-applications of the probes are illustrated followed by a summary of probes for selectively detecting cellular and subcellular thiols.


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.


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