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1. Photon Diffusion in Microscale Solids

Author

Das, Avijit, Brown, Andrew K., Mah, Merlin L., and Talghader, Joseph J.

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

This paper presents a theoretical and experimental investigation of photon diffusion in highly absorbing microscale graphite. An Nd:YAG continuous wave (CW) laser is used to heat the graphite samples with thicknesses of 40 microns and 100 microns. Optical intensities of 10 kW/cm^2 and 20 kW/cm^2 are used in laser heating. The graphite samples are heated to temperatures of thousands of kelvins within milliseconds, which are recorded by a 2-color, high-speed pyrometer. To compare the observed temperatures, the differential equation of heat conduction is solved across the samples with proper initial and boundary conditions. In addition to lattice vibrations, photon diffusion is incorporated into the analytical model of thermal conductivity for solving the heat equation. The numerical simulations showed close matching between experiment and theory only when including the photon diffusion equations and existing material properties data found in the previously published works with no fitting constants. The results indicate that the commonly-overlooked mechanism of photon diffusion dominates the heat transfer of many microscale structures near their evaporation temperatures. In addition, the treatment explains the discrepancies between thermal conductivity measurements and theory that were previously described in the scientific literature., Comment: 8 pages, 7 figures, (N.B. there is a typo and minor correction in Table 1 and References in the online version of the journal, corrected and highlighted in this PDF)

Published
2023
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5. Contributors

Author

Backhaus, Marina, primary, Balint, Peter V., additional, Benis, Szabolcs, additional, Berner-Hammer, Hilde, additional, Bong, David, additional, Bouffard, J. Antonio, additional, Bridal, S. Lori, additional, Brown, Andrew K., additional, Bruyn, George, additional, Ramos, Paz Collado, additional, D'Agostino, Maria Antonietta, additional, Filippucci, Emilio, additional, Goitz, Henry, additional, Grassi, Walter, additional, Gutierrez, Marwin, additional, Iagnocco, Annamaria, additional, Irsay, Laszlo, additional, Jousse-Joulin, Sandrine, additional, Kaeley, Gurjit S., additional, Kane, David, additional, Kitchen, Joanne, additional, Klauser, Andrea Sabine, additional, Kong, Kok Ooi, additional, Lamuraglia, Michele, additional, Mandl, Peter, additional, Michaud, Johan, additional, de Miguel mendieta, Eugenio, additional, Möller, Ingrid, additional, Naredo, Esperanza, additional, O'Connor, Philip, additional, Patonay, Lajos, additional, Pineda, Carlos, additional, Robinson, Philip, additional, Schmidt, Wolfgang A., additional, Szkudlarek, Marcin, additional, Terslev, Lene, additional, and Wakefield, Richard J., additional

Published
2010
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11. Contributors

Author

Albert, Todd J., primary, Anderson, D. Greg, additional, Anderson, Paul A., additional, Andersson, Gunnar B.J., additional, Ashry, Reem, additional, Biscup, Robert S., additional, Bono, Christopher M., additional, Brown, Andrew K., additional, Burkus, J. Kenneth, additional, Cappucino, Andy, additional, Crockard, Alan, additional, Cunningham, Bryan, additional, Delamarter, Rick B., additional, Demetropoulos, Constantine K., additional, Díaz, Roberto, additional, Eck, Jason C., additional, Errico, Thomas J., additional, Falicov, Alexis, additional, Fayyazi, Amir H., additional, Garfin, Steven R., additional, Geisler, Fred H., additional, Gilbertson, Lars G., additional, Gornet, Matthew, additional, Grauer, Jonathan N., additional, Hacker, Robert J., additional, Haid, Regis W., additional, Herkowitz, Harry N., additional, Hilibrand, Alan S., additional, Kang, James D., additional, Kim, Choll W., additional, Kim, David H., additional, Kitchel, Scott H., additional, Kubeck, Justin P., additional, Kurtz, Steven M., additional, Kwon, Brian K., additional, Lawrence, James P., additional, Lee, Kenneth J.H., additional, LeHuec, Jean-Charles, additional, Levicoff, Eric A., additional, Lin, Eric, additional, Matthews, Hal, additional, McAfee, Paul, additional, Mummaneni, Praveen V., additional, Oguz, Erbil, additional, Okafor, Chukwuka, additional, van Ooij, André, additional, Peloza, John, additional, Perry, Andrew, additional, Pimenta, Luiz, additional, Podichetty, Vinod K., additional, Pradhan, Ben B., additional, Pryor, John, additional, Puschak, Thomas J., additional, Raushning, Wolfgang, additional, Rodts, Gerald E., additional, Sasso, Rick C., additional, Schweitzer, Mark, additional, Sekhon, Lali H.S., additional, Sengupta, Dilip K., additional, Shanti, Nael, additional, Singh, Kern, additional, Smith, Harvey E., additional, Smucker, Joseph D., additional, Stieber, Jonathan R., additional, Stock, Gordon H., additional, Tannoury, Chadi, additional, Taylor, William, additional, Traynelis, Vincent C., additional, Vaccaro, Alexander R., additional, Vadala, Gianluca, additional, Villarraga, Marta L., additional, Walker, David H., additional, Wang, Jeffrey C., additional, White, Andrew P., additional, Yuan, Hansen A., additional, and Zeiller, Steven C., additional

Published
2007
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25. Recommendations for rheumatology ultrasound training and practice in the UK.

Author

Atchia, Ismaël, Brown, Andrew K, Chitale, Sarang, Ciechomska, Anna, Estrach, Cristina, Karim, Zunaid, Wakefield, Richard J, and (BSRUSSIG), for the British Society for Rheumatology Ultrasound Special Interest Group

Subjects
*CONSENSUS (Social sciences), *ULTRASONIC imaging, *RHEUMATOLOGY, *MEDICAL protocols, *DELPHI method
Abstract

Objective The aim of this paper is to present a UK-based consensus of principles and recommendations to guide rheumatology US training and practice. Method A Delphi process was conducted involving 19 US experts representing each of the 14 regions of the UK. A working group of experienced British Society for Rheumatology Ultrasound Special Interest Group (BSRUSSIG) members made seven proposals that were presented to the whole group for further discussion. This resulted in minor modifications and seven preliminary recommendations. Members were then asked to anonymously agree or disagree with each recommendation using an electronic ballot. A threshold of 75% was used to determine consensus agreement. Results were collated by an independent chairperson and presented to the BSRUSSIG in a face to face meeting where agreement for each recommendation was ratified and an action plan agreed for dissemination of the results and future development work. Results Using a validated process, experts in rheumatology US have worked through an iterative process and have unanimously agreed seven recommendations for rheumatology training and practice. These cover a hierarchy of practice indications, education and training, including the need for practitioners to demonstrate lifelong learning, as well as a commitment to support mentors and trainers through the BSRUSSIG. Conclusion These are the first specific education and practice recommendations for rheumatology US in the UK and have been developed and endorsed by the BSRUSSIG. We intend that these proposals will help to support and validate rheumatology US practice and inform the development of future rheumatology training curricula and education programmes. [ABSTRACT FROM AUTHOR]

Published
2021
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31. Determining a Magnetic Resonance Imaging Inflammatory Activity Acceptable State Without Subsequent Radiographic Progression in Rheumatoid Arthritis:Results from a Followup MRI Study of 254 Patients in Clinical Remission or Low Disease Activity

Author

Gandjbakhch, Frédérique, Haavardsholm, Espen A, Conaghan, Philip G, Ejbjerg, Bo, Foltz, Violaine, Brown, Andrew K, Døhn, Uffe Møller, Lassere, Marissa, Freeston, Jane E, Olsen, Inge Christoffer, Bøyesen, Pernille, Bird, Paul, Fautrel, Bruno, Hetland, Merete Lund, Emery, Paul, Bourgeois, Pierre, Hørslev-Petersen, Kim, Kvien, Tore K, McQueen, Fiona M, Østergaard, Mikkel, Gandjbakhch, Frédérique, Haavardsholm, Espen A, Conaghan, Philip G, Ejbjerg, Bo, Foltz, Violaine, Brown, Andrew K, Døhn, Uffe Møller, Lassere, Marissa, Freeston, Jane E, Olsen, Inge Christoffer, Bøyesen, Pernille, Bird, Paul, Fautrel, Bruno, Hetland, Merete Lund, Emery, Paul, Bourgeois, Pierre, Hørslev-Petersen, Kim, Kvien, Tore K, McQueen, Fiona M, and Østergaard, Mikkel

Abstract

OBJECTIVE: To assess the predictive value of magnetic resonance imaging (MRI)-detected subclinical inflammation for subsequent radiographic progression in a longitudinal study of patients with rheumatoid arthritis (RA) in clinical remission or low disease activity (LDA), and to determine cutoffs for an MRI inflammatory activity acceptable state in RA in which radiographic progression rarely occurs.METHODS: Patients with RA in clinical remission [28-joint Disease Activity Score-C-reactive protein (DAS28-CRP) < 2.6, n = 185] or LDA state (2.6 ≤ DAS28-CRP < 3.2, n = 69) with longitudinal MRI and radiographic data were included from 5 cohorts (4 international centers). MRI were assessed according to the Outcome Measures in Rheumatology (OMERACT) RA MRI scoring system (RAMRIS). Statistical analyses included an underlying conditional logistic regression model stratified per cohort, with radiographic progression as dependent variable.RESULTS: A total of 254 patients were included in the multivariate analyses. At baseline, synovitis was observed in 95% and osteitis in 49% of patients. Radiographic progression was observed in 60 patients (24%). RAMRIS synovitis was the only independent predictive factor in multivariate analysis. ROC analysis identified a cutoff value for baseline RAMRIS synovitis score of 5 (maximum possible score 21). Rheumatoid factor (RF) status yielded a significant interaction with synovitis (p value = 0.044). RF-positive patients with a RAMRIS synovitis score of > 5 vs ≤ 5, had an OR of 4.4 (95% CI 1.72-11.4) for radiographic progression.CONCLUSION: High MRI synovitis score predicts radiographic progression in patients in clinical remission/LDA. A cutoff point for determining an MRI inflammatory activity acceptable state based on the RAMRIS synovitis score was established. Incorporating MRI in future remission criteria should be considered.

Published
2014

32. Musculoskeletal ultrasound including definitions for ultrasonographic pathology

Author

Wakefield, Richard J, Balint, Peter V, Szkudlarek, Marcin, Filippucci, Emilio, Backhaus, Marina, D'Agostino, Maria Antonietta, Sanchez, Esperanza Naredo, Iagnocco, Annamaria, Schmidt, Wolfgang A, Bruyn, George A W, Bruyn, George, Kane, David, O'Connor, Philip J, Manger, Bernhard, Joshua, Fred, Koski, Juhani, Grassi, Walter, Lassere, Marissa N D, Swen, Nanno, Kainberger, Franz, Klauser, Andrea, Ostergaard, Mikkel, Brown, Andrew K, Machold, Klaus P, and Conaghan, Philip G

Subjects
Settore MED/16 - REUMATOLOGIA, Synovitis, ultrasound, enthesopathy, erosions, synovitis, tenosynovitis, Synovial Membrane, Hypertrophy, Tenosynovitis, Arthritis, Rheumatoid, Terminology as Topic, Humans, Joints, Musculoskeletal System, Ultrasonography
Abstract

Ultrasound (US) has great potential as an outcome in rheumatoid arthritis trials for detecting bone erosions, synovitis, tendon disease, and enthesopathy. It has a number of distinct advantages over magnetic resonance imaging, including good patient tolerability and ability to scan multiple joints in a short period of time. However, there are scarce data regarding its validity, reproducibility, and responsiveness to change, making interpretation and comparison of studies difficult. In particular, there are limited data describing standardized scanning methodology and standardized definitions of US pathologies. This article presents the first report from the OMERACT ultrasound special interest group, which has compared US against the criteria of the OMERACT filter. Also proposed for the first time are consensus US definitions for common pathological lesions seen in patients with inflammatory arthritis.

Published
2005

33. Determining a Magnetic Resonance Imaging Inflammatory Activity Acceptable State Without Subsequent Radiographic Progression in Rheumatoid Arthritis: Results from a Followup MRI Study of 254 Patients in Clinical Remission or Low Disease Activity

Author

Gandjbakhch, Frédérique, primary, Haavardsholm, Espen A., additional, Conaghan, Philip G., additional, Ejbjerg, Bo, additional, Foltz, Violaine, additional, Brown, Andrew K., additional, Døhn, Uffe Møller, additional, Lassere, Marissa, additional, Freeston, Jane E., additional, Olsen, Inge Christoffer, additional, Bøyesen, Pernille, additional, Bird, Paul, additional, Fautrel, Bruno, additional, Hetland, Merete Lund, additional, Emery, Paul, additional, Bourgeois, Pierre, additional, Hørslev-Petersen, Kim, additional, Kvien, Tore K., additional, McQueen, Fiona M., additional, and Østergaard, Mikkel, additional

Published
2013
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35. Synovitis and osteitis are very frequent in rheumatoid arthritis clinical remission: results from an MRI study of 294 patients in clinical remission or low disease activity state

Author

Gandjbakhch, Frédérique, Conaghan, Philip G, Ejbjerg, Bo, Haavardsholm, Espen A, Foltz, Violaine, Brown, Andrew K, Møller Døhn, Uffe, Lassere, Marissa, Freeston, Jane, Bøyesen, Pernille, Bird, Paul, Fautrel, Bruno, Hetland, Merete Lund, Emery, Paul, Bourgeois, Pierre, Hørslev-Petersen, Kim, Kvien, Tore K, McQueen, Fiona, Østergaard, Mikkel, Gandjbakhch, Frédérique, Conaghan, Philip G, Ejbjerg, Bo, Haavardsholm, Espen A, Foltz, Violaine, Brown, Andrew K, Møller Døhn, Uffe, Lassere, Marissa, Freeston, Jane, Bøyesen, Pernille, Bird, Paul, Fautrel, Bruno, Hetland, Merete Lund, Emery, Paul, Bourgeois, Pierre, Hørslev-Petersen, Kim, Kvien, Tore K, McQueen, Fiona, and Østergaard, Mikkel

Abstract

In rheumatoid arthritis (RA), radiographic progression may occur despite clinical remission. This may be explained by subclinical inflammation. Magnetic resonance imaging (MRI) provides a greater sensitivity than clinical examination and radiography for assessing disease activity. Our objective was to determine the MRI characteristics of RA patients in clinical remission or low disease activity (LDA) state.

Published
2011

41. Synovitis and Osteitis Are Very Frequent in Rheumatoid Arthritis Clinical Remission: Results from an MRI Study of 294 Patients in Clinical Remission or Low Disease Activity State

Author

GANDJBAKHCH, FRÉDÉRIQUE, primary, CONAGHAN, PHILIP G., additional, EJBJERG, BO, additional, HAAVARDSHOLM, ESPEN A., additional, FOLTZ, VIOLAINE, additional, BROWN, ANDREW K., additional, MØLLER DØHN, UFFE, additional, LASSERE, MARISSA, additional, FREESTON, JANE, additional, BØYESEN, PERNILLE, additional, BIRD, PAUL, additional, FAUTREL, BRUNO, additional, HETLAND, MERETE LUND, additional, EMERY, PAUL, additional, BOURGEOIS, PIERRE, additional, HØRSLEV-PETERSEN, KIM, additional, KVIEN, TORE K., additional, McQUEEN, FIONA, additional, and ØSTERGAARD, MIKKEL, additional

Published
2011
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44. A New Classification of Thoracolumbar Injuries

Author

Vaccaro, Alexander R., primary, Lehman, Ronald A., additional, Hurlbert, R John, additional, Anderson, Paul A., additional, Harris, Mitchel, additional, Hedlund, Rune, additional, Harrop, James, additional, Dvorak, Marcel, additional, Wood, Kirkham, additional, Fehlings, Michael G., additional, Fisher, Charles, additional, Zeiller, Steven C., additional, Anderson, D Greg, additional, Bono, Christopher M., additional, Stock, Gordon H., additional, Brown, Andrew K., additional, Kuklo, Timothy, additional, and ??ner, F C., additional

Published
2005
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47. Determining a Magnetic Resonance Imaging Inflammatory Activity Acceptable State Without Subsequent Radiographic Progression in Rheumatoid Arthritis: Results from a Followup MRI Study of 254 Patients in Clinical Remission or Low Disease Activity.

Author

Gandjbakhch, Frédérique, Haavardsholm, Espen A., Conaghan, Philip G., Ejbjerg, Bo, Foltz, Violaine, Brown, Andrew K., Døhn, Uffe Møller, Lassere, Marissa, Freeston, Jane E., Olsen, Inge Christoffer, Bøyesen, Pernille, Bird, Paul, Fautrel, Bruno, Hetland, Merete Lund, Emery, Paul, Bourgeois, Pierre, Hørslev-Petersen, Kim, Kvien, Tore K., McQueen, Fiona M., and Østergaard, Mikkel

Published
2014
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48. Relationship between early bone mineral density changes and long-term function and radiographic progression in rheumatoid arthritis.

Author

Bejarano, Victoria, Hensor, Elizabeth, Green, Michael, Haugeberg, Glenn, Brown, Andrew K., Buch, Maya H., Emery, Paul, and Conaghan, Philip G.

Abstract

Objective To ascertain whether bone mineral density loss during the first year of treatment for early rheumatoid arthritis (RA) as assessed by dual x-ray absorptiometry (DXA) is associated with long-term function, quality of life, and radiographic progression. Methods Early RA patients, prior to commencing disease-modifying antirheumatic drug therapy, underwent evaluation with DXA scans of both hands, femoral neck, and lumbar spine at the time of diagnosis, then at 1 year and final followup at >6 years. Clinical and laboratory data and hands and feet radiographs were obtained at baseline and final followup. Results Sixty-four patients were assessed. At baseline, median disease duration was 6 months, mean 28-joint Disease Activity Score was 5.85, and median Health Assessment Questionnaire score was 1.38. Median followup was 6.4 years (range 5.1-7.2 years). For erosion scores, 86% of patients with hand bone density loss above the smallest detectable change after 1 year progressed versus 55% of those with no hand bone density loss ( P = 0.006). However, baseline radiographs showed a similar strength of association. Eighty-four percent of patients with erosions at baseline had erosion progression versus 57% of those with no baseline erosions ( P = 0.021). Additionally, first-year bone density loss was not associated with function and quality of life status at followup. Conclusion Hand bone loss during the first year of treatment in early RA, as assessed with DXA, was associated with a high likelihood of radiographic progression; however, in the current study this was not superior to baseline radiographs. Furthermore, it was not associated with patient-reported outcomes. [ABSTRACT FROM AUTHOR]

Published
2012
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49. Musculoskeletal ultrasound including definitions for ultrasonographic pathology

Author

Wakefield, Richard J., Balint, Peter V., Marcin Szkudlarek, Emilio Filippucci, Marina Backhaus, Agostino, Maria Antonietta D., Esperanza Naredo Sanchez, Annamaria Iagnocco, Schmidt, Wolfgang A., George Bruyn, David Kane, Connor, Philip J. O., Bernhard Manger, Fredrick Joshua, Juhani Koski, Walter Grassi, Lassere, Marissa N. D., Nanno Swen, Franz Kainberger, Andrea Klauser, Mikkel Ostergaard, Brown, Andrew K., Machold, Klaus P., and Conaghan, Philip G.

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