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1.
Biol Res ; 54(1): 39, 2021 Dec 14.
Article in English | MEDLINE | ID: covidwho-1577124

ABSTRACT

BACKGROUND: The aim of the study was to investigate the effect of mild cerebral hypoxia on haemoglobin oxygenation (HbO2), cerebrospinal fluid dynamics and cardiovascular physiology. To achieve this goal, four signals were recorded simultaneously: blood pressure, heart rate / electrocardiogram, HbO2 from right hemisphere and changes of subarachnoid space (SAS) width from left hemisphere. Signals were registered from 30 healthy, young participants (2 females and 28 males, body mass index = 24.5 ± 2.3 kg/m2, age 30.8 ± 13.4 years). RESULTS: We analysed the recorded signals using wavelet transform and phase coherence. We demonstrated for the first time that in healthy subjects exposed to mild poikilokapnic hypoxia there were increases in very low frequency HbO2 oscillations (< 0.052 Hz) in prefrontal cortex. Additionally, SAS fluctuation diminished in the whole frequency range which could be explained by brain oedema. CONCLUSIONS: Consequently the study provides insight into mechanisms governing brain response to a mild hypoxic challenge. Our study supports the notion that HbO2 and SAS width monitoring might be beneficial for patients with acute lung disease.


Subject(s)
Cerebrovascular Circulation , Lung Diseases , Adolescent , Adult , Female , Hemoglobins , Humans , Hypoxia , Male , Prefrontal Cortex , Spectroscopy, Near-Infrared , Young Adult
2.
Sensors (Basel) ; 21(21)2021 Oct 20.
Article in English | MEDLINE | ID: covidwho-1512555

ABSTRACT

Despite the wide range of clinical and research applications, the reliability of the absolute oxygenation measurements of continuous wave near-infrared spectroscopy sensors is often questioned, partially due to issues of standardization. In this study, we have compared the performances of 13 units of a continuous wave near-infrared spectroscopy device (PortaMon, Artinis Medical Systems, NL) to test their suitability for being used in the HEMOCOVID-19 clinical trial in 10 medical centers around the world. Detailed phantom and in vivo tests were employed to measure the precision and reproducibility of measurements of local blood oxygen saturation and total hemoglobin concentration under different conditions: for different devices used, different operators, for probe repositioning over the same location, and over time (hours/days/months). We have detected systematic differences between devices when measuring phantoms (inter-device variability, <4%), which were larger than the intra-device variability (<1%). This intrinsic variability is in addition to the variability during in vivo measurements on the forearm muscle resulting from errors in probe positioning and intrinsic physiological noise (<9%), which was also larger than the inter-device differences (<3%) during the same test. Lastly, we have tested the reproducibility of the protocol of the HEMOCOVID-19 clinical trial; that is, forearm muscle oxygenation monitoring during vascular occlusion tests over days. Overall, our conclusion is that these devices can be used in multi-center trials but care must be taken to characterize, follow-up, and statistically account for inter-device variability.


Subject(s)
Oximetry , Spectroscopy, Near-Infrared , Oxygen , Oxygen Consumption , Reproducibility of Results
3.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Article in English | MEDLINE | ID: covidwho-1486398

ABSTRACT

The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.


Subject(s)
Brain/physiology , Masks , Activities of Daily Living , Adult , Brain/blood supply , Brain/metabolism , COVID-19/prevention & control , Female , Healthy Volunteers , Hemodynamics , Humans , Male , Microcirculation , Monitoring, Physiologic , Oxygen/metabolism , SARS-CoV-2 , Spectroscopy, Near-Infrared , Young Adult
4.
J Am Chem Soc ; 143(45): 18827-18831, 2021 11 17.
Article in English | MEDLINE | ID: covidwho-1483090

ABSTRACT

Despite the importance of rapid and accurate detection of SARS-CoV-2 in controlling the COVID-19 pandemic, current diagnostic methods are static and unable to distinguish between viable/nonviable virus or directly reflect viral replication activity. Real-time imaging of protease activity specific to SARS-CoV-2 can overcome these issues but remains lacking. Herein, we report a near-infrared fluorescence (NIRF) activatable molecular probe (SARS-CyCD) for detection of SARS-CoV-2 protease in living mice. The probe comprises a hemicyanine fluorophore caged with a protease peptide substrate and a cyclodextrin unit, which function as an NIRF signaling moiety and a renal-clearable enabler, respectively. The peptide substrate of SARS-CyCD can be specifically cleaved by SARS-CoV-2 main protease (Mpro), resulting in NIRF signal activation and liberation of the renal-clearable fluorescent fragment (CyCD). Such a design not only allows sensitive detection of Mpro in the lungs of living mice after intratracheal administration but also permits optical urinalysis of SARS-CoV-2 infection. Thus, this study presents an in vivo sensor that holds potential in preclinical high-throughput drug screening and clinical diagnostics for respiratory viral infections.


Subject(s)
COVID-19/diagnosis , Kidney/metabolism , Molecular Probes/metabolism , Optical Imaging/methods , Animals , COVID-19/virology , Fluorescent Dyes/analysis , Fluorescent Dyes/metabolism , Humans , Lung/metabolism , Mice , Molecular Probes/analysis , SARS-CoV-2/enzymology , SARS-CoV-2/isolation & purification , Spectroscopy, Near-Infrared , Urinalysis , Viral Matrix Proteins/metabolism
5.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Article in English | MEDLINE | ID: covidwho-1450314

ABSTRACT

The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.


Subject(s)
Brain/physiology , Masks , Activities of Daily Living , Adult , Brain/blood supply , Brain/metabolism , COVID-19/prevention & control , Female , Healthy Volunteers , Hemodynamics , Humans , Male , Microcirculation , Monitoring, Physiologic , Oxygen/metabolism , SARS-CoV-2 , Spectroscopy, Near-Infrared , Young Adult
6.
Sci Rep ; 11(1): 16201, 2021 08 10.
Article in English | MEDLINE | ID: covidwho-1351977

ABSTRACT

Optical spectroscopic techniques have been commonly used to detect the presence of biofilm-forming pathogens (bacteria and fungi) in the agro-food industry. Recently, near-infrared (NIR) spectroscopy revealed that it is also possible to detect the presence of viruses in animal and vegetal tissues. Here we report a platform based on visible and NIR (VNIR) hyperspectral imaging for non-contact, reagent free detection and quantification of laboratory-engineered viral particles in fluid samples (liquid droplets and dry residue) using both partial least square-discriminant analysis and artificial feed-forward neural networks. The detection was successfully achieved in preparations of phosphate buffered solution and artificial saliva, with an equivalent pixel volume of 4 nL and lowest concentration of 800 TU·[Formula: see text]L-1. This method constitutes an innovative approach that could be potentially used at point of care for rapid mass screening of viral infectious diseases and monitoring of the SARS-CoV-2 pandemic.


Subject(s)
Image Processing, Computer-Assisted/methods , Lentivirus Infections/diagnosis , Molecular Diagnostic Techniques/methods , Spectroscopy, Near-Infrared/methods , HEK293 Cells , Humans , Image Processing, Computer-Assisted/standards , Lentivirus/isolation & purification , Lentivirus/pathogenicity , Lentivirus Infections/virology , Molecular Diagnostic Techniques/standards , Point-of-Care Systems , Saliva/virology , Sensitivity and Specificity , Spectroscopy, Near-Infrared/standards
7.
Chem Commun (Camb) ; 57(51): 6229-6232, 2021 Jun 24.
Article in English | MEDLINE | ID: covidwho-1246405

ABSTRACT

Tracking the viral progression of SARS-CoV-2 in COVID-19 infected body tissues is an emerging need of the current pandemic. Imaging at near infrared second biological window (NIR-II) offers striking benefits over the other technologies to explore deep-tissue information. Here we design, synthesise and characterise a molecular probe that selectively targets the N-gene of SARS-CoV-2. Highly specific antisense oligonucleotides (ASOs) were conjugated to lead sulfide quantum dots using a UV-triggered thiol-ene click chemistry for the recognition of viral RNA. Our ex vivo imaging studies demonstrated that the probe exhibits aggregation induced NIR-II emission only in presence of SARS-CoV-2 RNA which can be attributed to the efficient hybridisation of the ASOs with their target RNA strands.


Subject(s)
COVID-19/diagnosis , COVID-19/virology , Fluorescent Dyes/chemistry , Oligonucleotides, Antisense/chemistry , Quantum Dots/chemistry , SARS-CoV-2/isolation & purification , Spectroscopy, Near-Infrared/methods , Animals , COVID-19/diagnostic imaging , COVID-19/metabolism , Click Chemistry/methods , Fluorescent Dyes/chemical synthesis , Humans , Lung/diagnostic imaging , Lung/metabolism , Lung/virology , Metal Nanoparticles/chemistry , Mice , Mice, Inbred BALB C , Models, Animal , SARS-CoV-2/genetics , SARS-CoV-2/metabolism
8.
Sensors (Basel) ; 21(9)2021 May 09.
Article in English | MEDLINE | ID: covidwho-1238950

ABSTRACT

This study innovatively proposes a feature fusion technique to determine fatty acid content during rice storage. Firstly, a self-developed olfactory visualization sensor was used to capture the odor information of rice samples at different storage periods and a portable spectroscopy system was employed to collect the near-infrared (NIR) spectra during rice storage. Then, principal component analysis (PCA) was performed on the pre-processed olfactory visualization sensor data and the NIR spectra, and the number of the best principal components (PCs) based on the single technique model was optimized during the backpropagation neural network (BPNN) modeling. Finally, the optimal PCs were fused at the feature level, and a BPNN detection model based on the fusion feature was established to achieve rapid measurement of fatty acid content during rice storage. The experimental results showed that the best BPNN model based on the fusion feature had a good predictive performance where the correlation coefficient (RP) was 0.9265, and the root mean square error (RMSEP) was 1.1005 mg/100 g. The overall results demonstrate that the detection accuracy and generalization performance of the feature fusion model are an improvement on the single-technique data model; and the results of this study can provide a new technical method for high-precision monitoring of grain storage quality.


Subject(s)
Oryza , Algorithms , Fatty Acids , Least-Squares Analysis , Neural Networks, Computer , Spectroscopy, Near-Infrared
9.
ACS Appl Mater Interfaces ; 13(8): 10321-10327, 2021 Mar 03.
Article in English | MEDLINE | ID: covidwho-1087402

ABSTRACT

Early diagnosis of SARS-CoV-2 infection is critical for facilitating proper containment procedures, and a rapid, sensitive antigen assay is a critical step in curbing the pandemic. In this work, we report the use of a high-purity semiconducting (sc) single-walled carbon nanotube (SWCNT)-based field-effect transistor (FET) decorated with specific binding chemistry to assess the presence of SARS-CoV-2 antigens in clinical nasopharyngeal samples. Our SWCNT FET sensors, with functionalization of the anti-SARS-CoV-2 spike protein antibody (SAb) and anti-nucleocapsid protein antibody, detected the S antigen (SAg) and N antigen (NAg), reaching a limit of detection of 0.55 fg/mL for SAg and 0.016 fg/mL for NAg in calibration samples. SAb-functionalized FET sensors also exhibited good sensing performance in discriminating positive and negative clinical samples, indicating a proof of principle for use as a rapid COVID-19 antigen diagnostic tool with high analytical sensitivity and specificity at low cost.


Subject(s)
Antigens, Viral/analysis , Biosensing Techniques , COVID-19 Testing/instrumentation , Nanotubes, Carbon/chemistry , Semiconductors , Transistors, Electronic , COVID-19 Testing/methods , Calibration , Electrodes , Gold , Humans , Limit of Detection , Materials Testing , Microscopy, Atomic Force , Microscopy, Fluorescence , Nanotechnology , SARS-CoV-2 , Sensitivity and Specificity , Spectrophotometry, Ultraviolet , Spectroscopy, Near-Infrared , Spectrum Analysis, Raman , Spike Glycoprotein, Coronavirus/analysis
10.
Food Chem ; 353: 128718, 2021 Aug 15.
Article in English | MEDLINE | ID: covidwho-947222

ABSTRACT

Fraud in the food supply system will be exacerbated by shortages caused by climate change and COVID-19's impact. The dried herbs market exemplifies complex supply chains attractive to criminals seeking financial gain. Real-time remote testing is achievable through development of globally accessible chemometric models for portable near infrared devices, deployed throughout supply chains. This study describes building of models for detection of oregano adulteration, on portable near infrared devices, and comparison to a laboratory-based Fourier-Transform Infrared spectroscopy method. 33/34 portable devices were able to correctly classify 5 out of 6 samples successfully with all adulterated samples being correctly classified following the use of appropriate transferability pre-processing routines. The devices native setup shows limited ability to perform a true screening of oregano using the setup offered. However modifications to the setup could in the future offer a solution that facilitates fit-for-purpose real time detection of adulterated samples within the supply chain.


Subject(s)
Food Contamination/analysis , Origanum/chemistry , Laboratories , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Near-Infrared
11.
Anal Chem ; 92(19): 13396-13404, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-933642

ABSTRACT

Rapid, accurate, reliable, and risk-free tracking of pathogenic microorganisms at the single-cell level is critical to achieve efficient source control and prevent outbreaks of microbial infectious diseases. For the first time, we report a promising approach for integrating the concepts of a remarkably large Stokes shift and dual-recognition into a single matrix to develop a pathogenic microorganism stimuli-responsive ratiometric fluorescent nanoprobe with speed, cost efficiency, stability, ultrahigh specificity, and sensitivity. As a proof-of-concept, we selected the Gram-positive bacterium Staphylococcus aureus (S. aureus) as the target analyte model, which easily bound to its recognition aptamer and the broad-spectrum glycopeptide antibiotic vancomycin (Van). To improve the specificity and short sample-to-answer time, we employed classic noncovalent π-π stacking interactions as a driving force to trigger the binding of Van and aptamer dual-functionalized near-infrared (NIR) fluorescent Apt-Van-QDs to the surface of an unreported blue fluorescent π-rich electronic carbon nanoparticles (CNPs), achieving S. aureus stimuli-responsive ratiometric nanoprobe Apt-Van-QDs@CNPs. In the assembly of Apt-Van-QDs@CNPs, the blue CNPs (energy donor) and NIR Apt-Van-QDs (energy acceptor) became close to allow the fluorescence resonance energy transfer (FRET) process, leading to a remarkable blue fluorescence quenching for the CNPs at ∼465 nm and a clear NIR fluorescence enhancement for Apt-Van-QDs at ∼725 nm. In the presence of S. aureus, the FRET process from CNPs to Apt-Van-QDs was disrupted, causing the nanoprobe Apt-Van-QDs@CNPs to display a ratiometric fluorescent response to S. aureus, which exhibited a large Stokes shift of ∼260 nm and rapid sample-to-answer detection time (∼30.0 min). As expected, the nanoprobe Apt-Van-QDs@CNPs showed an ultrahigh specificity for ratiometric fluorescence detection of S. aureus with a good detection limit of 1.0 CFU/mL, allowing the assay at single-cell level. Moreover, we also carried out the precise analysis of S. aureus in actual samples with acceptable results. We believe that this work offers new insight into the rational design of efficient ratiometric nanoprobes for rapid on-site accurate screening of pathogenic microorganisms at the single-cell level in the early stages, especially during the worldwide spread of COVID-19 today.


Subject(s)
Bacteria/chemistry , Bacterial Infections/diagnosis , Bacterial Infections/microbiology , Biosensing Techniques/methods , Fluorescent Dyes/chemical synthesis , Nanotechnology/methods , Anti-Bacterial Agents/pharmacology , Aptamers, Nucleotide , COVID-19 , Coronavirus Infections/complications , Coronavirus Infections/microbiology , Fluorescence , Fluorescence Resonance Energy Transfer , Food Microbiology/methods , Humans , Nanoparticles , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/microbiology , Sensitivity and Specificity , Spectroscopy, Near-Infrared , Staphylococcal Infections/diagnosis , Staphylococcal Infections/microbiology , Staphylococcus aureus/chemistry , Vancomycin/pharmacology
12.
J Intensive Care Med ; 36(3): 376-380, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-841807

ABSTRACT

PURPOSE: Purpose of this report is to describe the feasibility of lingual pulse oximetry and lingual near-infrared spectroscopy (NIRS) in a COVID-19 patient to assess lingual tissue viability after several days of mechanical ventilation in the prone position. MATERIALS & METHODS: In a COVID-19 ICU-patient, the tongue became grotesquely swollen, hardened and protruding from the oral cavity after 20 h of mechanical ventilation uninterrupted in the prone position. To assess the doubtful viability of the tongue, pulse-oximetric hemoglobin O2-saturation (SpO2; Nellcor, OxiMax MAX-NI, Covidien, MA, USA) and NIRS-based, regional tissue O2-saturation measurements (rSO2; SenSmart, Nonin, MN, USA) were performed at the tongue. RESULTS: At the tongue, regular pulse-oximetric waveforms with a pulse-oximetric hemoglobin O2-saturation (SpO2) of 88% were recorded, i.e. only slightly lower than the SpO2 reading at the extremities at that time (90%). Lingual NIRS-based rSO2 measurements yielded stable tissue rSO2-values of 76-78%, i.e. values expected also in other adequately perfused and oxygenated (muscle-) tissues. CONCLUSION: Despite the alarming, clinical finding of a grotesquely swollen, rubber-hard tongue and clinical concerns on the adequacy of the tongue perfusion and oxygenation, our measurements of both arterial pulsatility (SpO2) and NIRS-based tissue oxygenation (rSO2) suggested adequate perfusion and oxygenation of the tongue, rendering non-vitality of the tongue, e.g. by lingual venous thrombosis, unlikely. To our knowledge, this is the first clinical report of lingual rSO2 measurement.


Subject(s)
COVID-19/therapy , Edema/physiopathology , Oximetry , Pulsatile Flow , Spectroscopy, Near-Infrared , Tongue Diseases/physiopathology , Tongue/blood supply , Aged , COVID-19/physiopathology , Compartment Syndromes/diagnosis , Edema/metabolism , Humans , Male , Patient Positioning , Prone Position , SARS-CoV-2 , Tongue/metabolism , Tongue Diseases/metabolism , Venous Thrombosis/diagnosis
13.
J Clin Monit Comput ; 35(3): 661-662, 2021 May.
Article in English | MEDLINE | ID: covidwho-649924

ABSTRACT

OBJECTIVE: Objective of this case report is to draw attention to a less known thrombotic complication associated with COVID-19, i.e., thrombosis of both radial arteries, with possible (long-term) consequences. THE CASE: In our COVID-19 ICU a 49-year-old male patient was admitted, with past medical history of obesity, smoking and diabetes, but no reported atherosclerotic complications. The patient had been admitted with severe hypoxemia and multiple pulmonary emboli were CT-confirmed. ICU-treatment included mechanical ventilation and therapeutic anticoagulation. Preparing the insertion of a new radial artery catheter for invasive blood pressure measurement and blood sampling, we detected that both radial arteries were non-pulsating and occluded: (a) Sonography showed the typical anatomical localization of both radial and ulnar arteries. However, Doppler-derived flow-signals could only be obtained from the ulnar arteries. (b) To test collateral arterial supply of the hand, a pulse-oximeter was placed on the index finger. Thereafter, the ulnar artery at the wrist was compressed. This compression caused an immediate loss of the finger's pulse-oximetry perfusion signal. The effect was reversible upon release of the ulnar artery. (c) To test for collateral perfusion undetectable by pulse-oximetry, we measured regional oxygen saturation (rSO2) of the thenar muscle by near-infrared spectroscopy (NIRS). Confirming our findings above, ulnar arterial compression demonstrated that thenar rSO2 was dependent on ulnar artery flow. The described development of bilateral radial artery occlusion in a relatively young and therapeutically anticoagulated patient with no history of atherosclerosis was unexpected. CONCLUSIONS: Since COVID-19 patients are at increased risk for arterial occlusion, it appears advisable to meticulously check for adequacy of collateral (hand-) perfusion, avoiding the harm of hand ischemia if interventions (e.g., catheterizations) at the radial or ulnar artery are intended.


Subject(s)
Arterial Occlusive Diseases/diagnostic imaging , Arterial Occlusive Diseases/etiology , COVID-19/complications , Radial Artery , SARS-CoV-2 , Arterial Occlusive Diseases/physiopathology , COVID-19/diagnostic imaging , COVID-19/physiopathology , Hand/blood supply , Hand/diagnostic imaging , Humans , Male , Middle Aged , Muscle, Skeletal/blood supply , Muscle, Skeletal/metabolism , Netherlands , Oximetry , Oxygen Consumption , Pandemics , Radial Artery/diagnostic imaging , Radial Artery/physiopathology , Regional Blood Flow , Spectroscopy, Near-Infrared , Ulnar Artery/diagnostic imaging , Ultrasonography, Doppler
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