Operando MRI for quantitative mapping of temperature and redox species concentrations in thermo-electrochemical cells

Abstract Low-grade waste heat is an abundant and underutilised energy source, and the promise of thermo-electrochemical cells to harvest this resource and power applications such as wearable devices and sensors is increasingly being realised. However, despite substantial advances in performance in recent years, understanding the interior processes occurring within these devices remains a challenge. Here we report an operando magnetic resonance imaging (MRI) approach that can provide quantitative spatial maps of electrolyte temperature and redox ion concentrations in functioning thermo-electrochemical cells. Time-resolved images are obtained from liquid and gel electrolytes, allowing the effects of redox reactions and competing mass transfer effects such as thermophoresis and diffusion to be visualised and correlated with the device performance via simultaneous electrochemical measurements. This method offers valuable insights into these devices and will greatly aid their future design and optimisation.

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Operando magnetic resonance imaging for mapping of temperature and redox species in thermo-electrochemical cells

Nature Communications ◽

10.1038/s41467-021-26813-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Isuru E. Gunathilaka ◽

Jennifer M. Pringle ◽

Luke A. O’Dell

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Waste Heat ◽

Cost Effective ◽

Low Grade ◽

Electrochemical Cells ◽

Resonance Imaging ◽

Redox Species ◽

Time Resolved ◽

Mass Transfer Processes

AbstractLow-grade waste heat is an abundant and underutilised energy source. In this context, thermo-electrochemical cells (i.e., systems able to harvest heat to generate electricity) are being intensively studied to deliver the promises of efficient and cost-effective energy harvesting and electricity generation. However, despite the advances in performance disclosed in recent years, understanding the internal processes occurring within these devices is challenging. In order to shed light on these mechanisms, here we report an operando magnetic resonance imaging approach that can provide quantitative spatial maps of the electrolyte temperature and redox ion concentrations in functioning thermo-electrochemical cells. Time-resolved images are obtained from liquid and gel electrolytes, allowing the observation of the effects of redox reactions and competing mass transfer processes such as thermophoresis and diffusion. We also correlate the physicochemical properties of the system with the device performance via simultaneous electrochemical measurements.

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Quantitative Mapping of Individual Voxels in the Peritumoral Region of Glioblastoma to Distinguish Between Tumor Infiltration and Edema

10.21203/rs.3.rs-263971/v1 ◽

2021 ◽

Author(s):

Archya Dasgupta ◽

Benjamin Geraghty ◽

Pejman Jabehdar Maralani ◽

Nauman Malik ◽

Michael Sandhu ◽

...

Keyword(s):

Support Vector Machine Classifier ◽

Vasogenic Edema ◽

Support Vector ◽

Low Grade ◽

Imaging Data ◽

Quantitative Mapping ◽

Apparent Diffusion ◽

Apparent Diffusion Coefficient Maps ◽

Magnetic Resonance Imaging Mri ◽

Infiltrative Tumor

Abstract Purpose: The peritumoral region (PTR) in glioblastoma (GBM) represents a combination of infiltrative tumor and vasogenic edema, which are indistinguishable on magnetic resonance imaging (MRI). We developed a radiomic signature by using imaging data from low grade glioma (LGG) (marker of tumor) and PTR of brain metastasis (BM) (marker of edema) and applied it on the GBM PTR to generate probabilistic maps. Methods: 270 features were extracted from T1-weighted, T2-weighted, and apparent diffusion coefficient maps in over 3.5 million voxels of LGG (36 segments) and BM (45 segments) scanned in a 1.5 T MRI. A support vector machine classifier was used to develop the radiomics model from approximately 50% voxels (downsampled to 10%) and validated with the remaining. The model was applied to over 575,000 voxels of the PTR of 10 patients with GBM to generate a quantitative map using Platt scaling (infiltrative tumor vs. edema). Results: The radiomics model had an accuracy of 0.92 and 0.79 in the training and test set, respectively (LGG vs. BM). When extrapolated on the GBM PTR, 9 of 10 patients had a higher percentage of voxels with a tumor-like signature over radiological recurrence areas. In 7 of 10 patients, the areas under curves (AUC) were >0.50 confirming a positive correlation. Including all the voxels from the GBM patients, the infiltration signature had an AUC of 0.61 to predict recurrence.Conclusion: A radiomic signature can demarcate areas of microscopic tumors from edema in the PTR of GBM, which correlates with areas of future recurrence.

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Thermo-electrochemical cells based on polymer and mineral hydrogels for low-grade waste heat conversion

10.1063/1.5009841 ◽

2017 ◽

Cited By ~ 2

Author(s):

Alexandr Shindrov ◽

Denis Artyukhov ◽

Maria Vikulova ◽

Nikolay Spirin ◽

Natalya Nikitina ◽

...

Keyword(s):

Waste Heat ◽

Low Grade ◽

Electrochemical Cells

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Sludge Disposal from an Island Community

Water Science & Technology ◽

10.2166/wst.1992.0335 ◽

1992 ◽

Vol 25 (12) ◽

pp. 33-47 ◽

Cited By ~ 1

Author(s):

T. S. C. Gross ◽

R. R. Cohen

Keyword(s):

Agricultural Land ◽

Waste Heat ◽

Treatment Plant ◽

Small Island ◽

Low Grade ◽

Sludge Disposal ◽

Disposal Option ◽

Total Process ◽

Island Community ◽

Farm Produce

The small island of Jersey is served by a single wastewater treatment plant at Bellozanne. Since its inception some 30 years ago the sludge produced has been used on agricultural land. Inevitably there are circumstances which prevent this happening without interruption, eg, poor weather, or seasonal demand. On these occasions, the island has no other disposal option to fall back on. Furthermore, concerns over the practice have created a perception that it might be doing harm to the ‘quality' of the farm produce. The responsible body, the Public Services Department, formulated a flexible, multiple option solution and commissioned Halcrow to engineer the capital works. The works centre around a thermal drying plant using biogas produced by the digestion process as the main fuel. Waste heat is recovered for digester heating making the total process potentially self sufficient in energy. At the same time, the bulk of the product is reduced considerably, providing an easily transported material with potential for use directly on the land as a fertilizer substitute or as a low grade fuel. Farfrom being a disposal problem requiring manpower and expense, sludge will soon be regarded by the States of Jersey as a valuable resource with a revenue potential.

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Neuroimaging of Children With Takayasu Arteritis

Journal of Child Neurology ◽

10.1177/0883073821991287 ◽

2021 ◽

pp. 088307382199128

Author(s):

Hafize Emine Sönmez ◽

Ferhat Demir ◽

Semanur Özdel ◽

Şerife Gül Karadağ ◽

Esra Bağlan ◽

...

Keyword(s):

Takayasu Arteritis ◽

Internal Carotid ◽

Laboratory Data ◽

Left Middle Cerebral Artery ◽

Mri Findings ◽

Cranial Mri ◽

Magnetic Resonance Imaging Mri ◽

The Right ◽

And Diffusion ◽

Left Middle

Objective: Takayasu arteritis is a rare granulomatous chronic vasculitis that affects the aorta and its main branches. Neurologic manifestations can accompany the disease; however, there is no study on neuroimaging in children with Takayasu arteritis. Therefore, we aimed to evaluate cranial magnetic resonance imaging (MRI) in pediatric Takayasu arteritis patients. Materials and Methods: Demographic, clinical, and laboratory data were obtained retrospectively. Results: The study included 15 pediatric Takayasu arteritis patients. All patients presented with constitutional symptoms. Additionally, 6 patients suffered from headache, 2 had syncope, 1 had loss of consciousness, and 1 had convulsion. All patients underwent cranial and diffusion MRI a median 12 months after diagnosis. Cranial MRI findings were normal in 12 patients, whereas 3 patients had abnormal findings, as follows: stenosis in the M1 and M2 segments of the left middle cerebral artery (n = 1); diffuse thinning of the right internal carotid, middle cerebral, and right vertebral and basilar artery (n = 1); as a sequela, areas of focal gliosis in both the lateral ventricular and posterior periventricular regions (n = 1). Among these 3 patients, 1 had no neurologic complaints. Conclusion: Abnormal MRI findings can be observed in pediatric Takayasu arteritis patients, even those that are asymptomatic; therefore, clinicians should carefully evaluate neurologic involvement in all pediatric Takayasu arteritis patients.

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The Added Value of Inflow-Based Vascular-Space-Occupancy and Diffusion-Weighted Imaging in Preoperative Grading of Gliomas

Neurodegenerative Diseases ◽

10.1159/000512545 ◽

2021 ◽

pp. 1-8

Author(s):

Haimei Cao ◽

Xiang Xiao ◽

Jun Hua ◽

Guanglong Huang ◽

Wenle He ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Roc Curve ◽

Diffusion Weighted Imaging ◽

Low Grade ◽

High Grade ◽

Mr Images ◽

Vascular Space ◽

Diffusion Weighted ◽

High Grade Gliomas ◽

And Diffusion

Objectives: The present study aimed to study whether combined inflow-based vascular-space-occupancy (iVASO) MR imaging (MRI) and diffusion-weighted imaging (DWI) improve the diagnostic accuracy in the preoperative grading of gliomas. Methods: Fifty-one patients with histopathologically confirmed diffuse gliomas underwent preoperative structural MRI, iVASO, and DWI. We performed 2 qualitative consensus reviews: (1) structural MR images alone and (2) structural MR images with iVASO and DWI. Relative arteriolar cerebral blood volume (rCBVa) and minimum apparent diffusion coefficient (mADC) were compared between low-grade and high-grade gliomas. Receiver operating characteristic (ROC) curve analysis was performed to compare the tumor grading efficiency of rCBVa, mADC, and the combination of the two parameters. Results: Two observers diagnosed accurate tumor grade in 40 of 51 (78.4%) patients in the first review and in 46 of 51 (90.2%) in the second review. Both rCBVa and mADC showed significant differences between low-grade and high-grade gliomas. ROC analysis gave a threshold value of 1.52 for rCBVa and 0.85 × 10−3 mm2/s for mADC to provide a sensitivity and specificity of 88.0 and 81.2% and 100.0 and 68.7%, respectively. The area under the ROC curve (AUC) was 0.87 and 0.85 for rCBVa and mADC, respectively. The combination of rCBVa and mADC values increased the AUC to 0.92. Conclusion: The combined application of iVASO and DWI may improve the diagnostic accuracy of glioma grading.

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Breast involvement of hematological malignancies: imaging and clinical findings

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-021-00558-2 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Gamze Durhan ◽

Figen Demirkazık

Keyword(s):

Hematological Malignancies ◽

Clinical Findings ◽

Accurate Diagnosis ◽

Radiological Findings ◽

Breast Masses ◽

Appropriate Treatment ◽

Magnetic Resonance Imaging Mri ◽

Type 3 ◽

And Diffusion

Abstract Background Breast involvement of hematological malignancies is a very rare entity. Accurate diagnosis is essential for appropriate treatment. The aim of this study was to clarify the clinical and radiological findings of hematological malignancy breast involvement and to describe possible pitfalls in diagnosis. Results The images of 20 patients with breast involvement of hematological malignancies were retrospectively evaluated on ultrasonography, mammography, and magnetic resonance imaging (MRI) and the findings were reported. Bilaterality was seen only in cases with secondary involvement, and there was no marked difference between primary and secondary breast involvement of hematological malignancies. All patients underwent ultrasonography examination. According to ultrasonography, breast masses were most frequently irregular in shape (11/20, 55%) with non-circumscribed margins (11/20, 55%). Posterior acoustic enhancement was noted in 14 cases (70%). Posterior shadowing was not observed in any of the patients. Mammography was available in 10 patients. Microcalcification was not observed in any patient on mammography. MRI was available in four patients. Hyperintensity in T2-weighted images, type 2 or type 3 dynamic curve, and diffusion restriction were observed in all cases. Conclusions Hematological malignancies may mimic both benign breast lesions and breast carcinoma. Familiarity with the radiological features of hematological malignancies can help accurate diagnosis.

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Characterization of multiple sclerosis neuroinflammation and neurodegeneration with relaxation and diffusion basis spectrum imaging

Multiple Sclerosis Journal ◽

10.1177/13524585211023345 ◽

2021 ◽

pp. 135245852110233

Author(s):

Irene M Vavasour ◽

Peng Sun ◽

Carina Graf ◽

Jackie T Yik ◽

Shannon H Kolind ◽

...

Keyword(s):

Multiple Sclerosis ◽

Specific Information ◽

Axonal Loss ◽

Normal Appearing White Matter ◽

Relapsing Remitting ◽

Tissue Changes ◽

Spectrum Imaging ◽

Magnetic Resonance Imaging Mri ◽

And Diffusion

Background: Advanced magnetic resonance imaging (MRI) methods can provide more specific information about various microstructural tissue changes in multiple sclerosis (MS) brain. Quantitative measurement of T1 and T2 relaxation, and diffusion basis spectrum imaging (DBSI) yield metrics related to the pathology of neuroinflammation and neurodegeneration that occurs across the spectrum of MS. Objective: To use relaxation and DBSI MRI metrics to describe measures of neuroinflammation, myelin and axons in different MS subtypes. Methods: 103 participants (20 clinically isolated syndrome (CIS), 33 relapsing-remitting MS (RRMS), 30 secondary progressive MS and 20 primary progressive MS) underwent quantitative T1, T2, DBSI and conventional 3T MRI. Whole brain, normal-appearing white matter, lesion and corpus callosum MRI metrics were compared across MS subtypes. Results: A gradation of MRI metric values was seen from CIS to RRMS to progressive MS. RRMS demonstrated large oedema-related differences, while progressive MS had the most extensive abnormalities in myelin and axonal measures. Conclusion: Relaxation and DBSI-derived MRI measures show differences between MS subtypes related to the severity and composition of underlying tissue damage. RRMS showed oedema, demyelination and axonal loss compared with CIS. Progressive MS had even more evidence of increased oedema, demyelination and axonal loss compared with CIS and RRMS.

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