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Machin G, Simpson R, Sutton G, Bond W, Heaps E, Hayes M, Korniliou S, McMillan J, Norman J, Sposito A, Panicker V, Adamska A, Allen A, Bernard R, Clarke S, Clifford J, Gallagher C, Jowsey J. Novel thermometry approaches to facilitate safe and effective monitoring of nuclear material containers. Nuclear Engineering and Design 2021. [DOI: 10.1016/j.nucengdes.2020.110939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Petrova NL, Donaldson NK, Tang W, MacDonald A, Allen J, Lomas C, Leech N, Ainarkar S, Bevans J, Plassmann P, Kluwe B, Ring F, Whittam A, Rogers L, McMillan J, Simpson R, Donaldson ANA, Machin G, Edmonds ME. Infrared thermography and ulcer prevention in the high-risk diabetic foot: data from a single-blind multicentre controlled clinical trial. Diabet Med 2020; 37:95-104. [PMID: 31629373 DOI: 10.1111/dme.14152] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/14/2019] [Indexed: 11/28/2022]
Abstract
AIM To assess the usefulness of monthly thermography and standard foot care to reduce diabetic foot ulcer recurrence. METHODS People with diabetes (n = 110), neuropathy and history of ≥ 1 foot ulcer participated in a single-blind multicentre clinical trial. Feet were imaged with a novel thermal imaging device (Diabetic Foot Ulcer Prevention System). Participants were randomized to intervention (active thermography + standard foot care) or control (blinded thermography + standard foot care) and were followed up monthly until ulcer recurrence or for 12 months. Foot thermograms of participants from the intervention group were assessed for hot spots (areas with temperature ≥ 2.2°C higher than the corresponding contralateral site) and acted upon as per local standards. RESULTS After 12 months, 62% of participants were ulcer-free in the intervention group and 56% in the control group. The odds ratios of ulcer recurrence (intervention vs control) were 0.82 (95% CI 0.38, 1.8; P = 0.62) and 0.55 (95% CI 0.21, 1.4; P = 0.22) in univariate and multivariate logistic regression analyses, respectively. The hazard ratios for the time to ulcer recurrence (intervention vs control) were 0.84 (95% CI 0.45, 1.6; P = 0.58) and 0.67 (95% CI 0.34, 1.3; P = 0.24) in univariate and multivariate Cox regression analyses, respectively. CONCLUSIONS Monthly intervention with thermal imaging did not result in a significant reduction in ulcer recurrence rate or increased ulcer-free survival in this cohort at high risk of foot ulcers. This trial has, however, informed the design of a refined study with longer follow-up and group stratification, further aiming to assess the efficacy of thermography to reduce ulcer recurrence.
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Affiliation(s)
- N L Petrova
- Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, London, UK
- Division of Diabetes and Nutritional Sciences, King's College London, London, UK
| | - N K Donaldson
- Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, London, UK
| | - W Tang
- Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, London, UK
| | - A MacDonald
- Microvascular Diagnostics, Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | - J Allen
- Microvascular Diagnostics, Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | - C Lomas
- Podiatry Department, Diabetes Centre, Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | - N Leech
- Podiatry Department, Diabetes Centre, Newcastle-upon-Tyne Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | - S Ainarkar
- Community Podiatry Department, Pennine Acute Hospitals Trust, Manchester, UK
| | - J Bevans
- Community Podiatry Department, Pennine Acute Hospitals Trust, Manchester, UK
| | | | - B Kluwe
- Department of Computing, University of South Wales, Pontypridd, UK
| | - F Ring
- Department of Computing, University of South Wales, Pontypridd, UK
| | - A Whittam
- Temperature and Humidity, National Physical Laboratory, London, UK
| | - L Rogers
- Temperature and Humidity, National Physical Laboratory, London, UK
| | - J McMillan
- Temperature and Humidity, National Physical Laboratory, London, UK
| | - R Simpson
- Temperature and Humidity, National Physical Laboratory, London, UK
| | - A N A Donaldson
- Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, London, UK
| | - G Machin
- Temperature and Humidity, National Physical Laboratory, London, UK
| | - M E Edmonds
- Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, London, UK
- Division of Diabetes and Nutritional Sciences, King's College London, London, UK
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Machin G, Simpson R, McEvoy HC, Whittam A. NPL contributions to the standardisation and validation of contemporary medical thermometry methods. Physiol Meas 2019; 40:05TR01. [PMID: 30943464 DOI: 10.1088/1361-6579/ab15b0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Since the advent of reliable mercury-in-glass thermometers in the latter part of the 19th century the practice of clinical thermometry was thought to be a solved issue. However with advances in technology there has, in recent decades, been a proliferation of temperature measurement methods applied to medical science. Many of these have been introduced because of the clinical benefit they confer, nevertheless, in some cases the metrological foundation and infrastructure to ensure sound measurement was not in place. This paper will focus on the standardisation activity undertaken by the UK's National Physical Laboratory (NPL) to support reliable temperature measurement, using a number of innovative methods, in a clinical setting.
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Affiliation(s)
- G Machin
- Temperature and Humidity Group, National Physical Laboratory, Teddington, London, United Kingdom. Author to whom any correspondence should be addressed
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Petrova NL, Whittam A, MacDonald A, Ainarkar S, Donaldson AN, Bevans J, Allen J, Plassmann P, Kluwe B, Ring F, Rogers L, Simpson R, Machin G, Edmonds ME. Reliability of a novel thermal imaging system for temperature assessment of healthy feet. J Foot Ankle Res 2018; 11:22. [PMID: 29854007 PMCID: PMC5975531 DOI: 10.1186/s13047-018-0266-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/16/2018] [Indexed: 12/30/2022] Open
Abstract
Background Thermal imaging is a useful modality for identifying preulcerative lesions (“hot spots”) in diabetic foot patients. Despite its recognised potential, at present, there is no readily available instrument for routine podiatric assessment of patients at risk. To address this need, a novel thermal imaging system was recently developed. This paper reports the reliability of this device for temperature assessment of healthy feet. Methods Plantar skin foot temperatures were measured with the novel thermal imaging device (Diabetic Foot Ulcer Prevention System (DFUPS), constructed by Photometrix Imaging Ltd) and also with a hand-held infrared spot thermometer (Thermofocus® 01500A3, Tecnimed, Italy) after 20 min of barefoot resting with legs supported and extended in 105 subjects (52 males and 53 females; age range 18 to 69 years) as part of a multicentre clinical trial. The temperature differences between the right and left foot at five regions of interest (ROIs), including 1st and 4th toes, 1st, 3rd and 5th metatarsal heads were calculated. The intra-instrument agreement (three repeated measures) and the inter-instrument agreement (hand-held thermometer and thermal imaging device) were quantified using intra-class correlation coefficients (ICCs) and the 95% confidence intervals (CI). Results Both devices showed almost perfect agreement in replication by instrument. The intra-instrument ICCs for the thermal imaging device at all five ROIs ranged from 0.95 to 0.97 and the intra-instrument ICCs for the hand-held-thermometer ranged from 0.94 to 0.97. There was substantial to perfect inter-instrument agreement between the hand-held thermometer and the thermal imaging device and the ICCs at all five ROIs ranged between 0.94 and 0.97. Conclusions This study reports the performance of a novel thermal imaging device in the assessment of foot temperatures in healthy volunteers in comparison with a hand-held infrared thermometer. The newly developed thermal imaging device showed very good agreement in repeated temperature assessments at defined ROIs as well as substantial to perfect agreement in temperature assessment with the hand-held infrared thermometer. In addition to the reported non-inferior performance in temperature assessment, the thermal imaging device holds the potential to provide an instantaneous thermal image of all sites of the feet (plantar, dorsal, lateral and medial views). Trial registration Diabetic Foot Ulcer Prevention System NCT02317835, registered December 10, 2014
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Affiliation(s)
- N L Petrova
- 1Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS UK.,2Division of Diabetes and Nutritional Sciences, King's College London, London, UK
| | - A Whittam
- 3Temperature and Humidity, National Physical Laboratory, London, UK
| | - A MacDonald
- 4Microvascular Diagnostics, Northern Medical Physics and Clinical Engineering, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, UK
| | - S Ainarkar
- 5Community Podiatry Department, Pennine Acute Hospitals NHS Trust, Manchester, UK
| | - A N Donaldson
- 1Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS UK
| | - J Bevans
- 5Community Podiatry Department, Pennine Acute Hospitals NHS Trust, Manchester, UK
| | - J Allen
- 4Microvascular Diagnostics, Northern Medical Physics and Clinical Engineering, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, UK
| | | | - B Kluwe
- 7Department of Computing, University of South Wales, Pontypridd, UK
| | - F Ring
- 7Department of Computing, University of South Wales, Pontypridd, UK
| | - L Rogers
- 3Temperature and Humidity, National Physical Laboratory, London, UK
| | - R Simpson
- 3Temperature and Humidity, National Physical Laboratory, London, UK
| | - G Machin
- 3Temperature and Humidity, National Physical Laboratory, London, UK
| | - M E Edmonds
- 1Diabetic Foot Clinic, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS UK.,2Division of Diabetes and Nutritional Sciences, King's College London, London, UK
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Fischer J, Fellmuth B, Gaiser C, Zandt T, Pitre L, Sparasci F, Plimmer MD, de Podesta M, Underwood R, Sutton G, Machin G, Gavioso RM, Ripa DM, Steur PPM, Qu J, Feng XJ, Zhang J, Moldover MR, Benz SP, White DR, Gianfrani L, Castrillo A, Moretti L, Darquié B, Moufarej E, Daussy C, Briaudeau S, Kozlova O, Risegari L, Segovia JJ, Martín MC, del Campo D. The Boltzmann project. Metrologia 2018; 55:10.1088/1681-7575/aaa790. [PMID: 31080297 PMCID: PMC6508687 DOI: 10.1088/1681-7575/aaa790] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The International Committee for Weights and Measures (CIPM), at its meeting in October 2017, followed the recommendation of the Consultative Committee for Units (CCU) on the redefinition of the kilogram, ampere, kelvin and mole. For the redefinition of the kelvin, the Boltzmann constant will be fixed with the numerical value 1.380 649 × 10-23 J K-1. The relative standard uncertainty to be transferred to the thermodynamic temperature value of the triple point of water will be 3.7 × 10-7, corresponding to an uncertainty in temperature of 0.10 mK, sufficiently low for all practical purposes. With the redefinition of the kelvin, the broad research activities of the temperature community on the determination of the Boltzmann constant have been very successfully completed. In the following, a review of the determinations of the Boltzmann constant k, important for the new definition of the kelvin and performed in the last decade, is given.
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Affiliation(s)
- J Fischer
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - B Fellmuth
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - C Gaiser
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - T Zandt
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - L Pitre
- Laboratoire Commun de Métrologie (LNE-CNAM), 61 rue du Landy, 93210 La Plaine-Saint-Denis, France
| | - F Sparasci
- Laboratoire Commun de Métrologie (LNE-CNAM), 61 rue du Landy, 93210 La Plaine-Saint-Denis, France
| | - M D Plimmer
- Laboratoire Commun de Métrologie (LNE-CNAM), 61 rue du Landy, 93210 La Plaine-Saint-Denis, France
| | - M de Podesta
- National Physical Laboratory (NPL), Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - R Underwood
- National Physical Laboratory (NPL), Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - G Sutton
- National Physical Laboratory (NPL), Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - G Machin
- National Physical Laboratory (NPL), Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - R M Gavioso
- Istituto Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, 10135 Torino, Italy
| | - D Madonna Ripa
- Istituto Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, 10135 Torino, Italy
| | - P P M Steur
- Istituto Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, 10135 Torino, Italy
| | - J Qu
- National Institute of Metrology (NIM), Beijing 100029, People’s Republic of China
| | - X J Feng
- National Institute of Metrology (NIM), Beijing 100029, People’s Republic of China
| | - J Zhang
- National Institute of Metrology (NIM), Beijing 100029, People’s Republic of China
| | - M R Moldover
- National Institute of Standards and Technology (NIST), Gaithersburg and Boulder, United States of America
| | - S P Benz
- National Institute of Standards and Technology (NIST), Gaithersburg and Boulder, United States of America
| | - D R White
- Measurement Standards Laboratory of New Zealand (MSL), Lower Hutt, New Zealand
| | - L Gianfrani
- Dipartimento di Matematica e Fisica, Università degli Studi della Campania “Luigi Vanvitelli” Viale Lincoln 5, 81100 Caserta, Italy
| | - A Castrillo
- Dipartimento di Matematica e Fisica, Università degli Studi della Campania “Luigi Vanvitelli” Viale Lincoln 5, 81100 Caserta, Italy
| | - L Moretti
- Dipartimento di Matematica e Fisica, Università degli Studi della Campania “Luigi Vanvitelli” Viale Lincoln 5, 81100 Caserta, Italy
| | - B Darquié
- Université Paris 13, Sorbonne Paris Cité, CNRS, UMR 7538, Laboratoire de Physique des Lasers (LPL), 93430 Villetaneuse, France
| | - E Moufarej
- Université Paris 13, Sorbonne Paris Cité, CNRS, UMR 7538, Laboratoire de Physique des Lasers (LPL), 93430 Villetaneuse, France
| | - C Daussy
- Université Paris 13, Sorbonne Paris Cité, CNRS, UMR 7538, Laboratoire de Physique des Lasers (LPL), 93430 Villetaneuse, France
| | - S Briaudeau
- Laboratoire National de Métrologie et d’essais (LNE), 1 rue Gaston Boissier, 75724 Paris, France
| | - O Kozlova
- Laboratoire National de Métrologie et d’essais (LNE), 1 rue Gaston Boissier, 75724 Paris, France
| | - L Risegari
- Laboratoire National de Métrologie et d’essais (LNE), 1 rue Gaston Boissier, 75724 Paris, France
| | - J J Segovia
- TERMOCAL Research Group, University of Valladolid (UVa), Paseo del Cauce 59, 47011 Valladolid, Spain
| | - M C Martín
- TERMOCAL Research Group, University of Valladolid (UVa), Paseo del Cauce 59, 47011 Valladolid, Spain
| | - D del Campo
- Centro Español de Metrología (CEM), Alfar 2, 28760 Tres Cantos, Madrid, Spain
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Machin G, Whittam A, Ainarkar S, Allen J, Bevans J, Edmonds M, Kluwe B, Macdonald A, Petrova N, Plassmann P, Ring F, Rogers L, Simpson R. A medical thermal imaging device for the prevention of diabetic foot ulceration. Physiol Meas 2017; 38:420-430. [DOI: 10.1088/1361-6579/aa56b1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Machin G, Chu B. High-quality blackbody sources for infrared thermometry and thermography between −40 and 1000°C. The Imaging Science Journal 2016. [DOI: 10.1080/13682199.2000.11784341] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Woolliams ER, Anhalt K, Ballico M, Bloembergen P, Bourson F, Briaudeau S, Campos J, Cox MG, del Campo D, Dong W, Dury MR, Gavrilov V, Grigoryeva I, Hernanz ML, Jahan F, Khlevnoy B, Khromchenko V, Lowe DH, Lu X, Machin G, Mantilla JM, Martin MJ, McEvoy HC, Rougié B, Sadli M, Salim SGR, Sasajima N, Taubert DR, Todd ADW, Van den Bossche R, van der Ham E, Wang T, Whittam A, Wilthan B, Woods DJ, Woodward JT, Yamada Y, Yamaguchi Y, Yoon HW, Yuan Z. Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points. Philos Trans A Math Phys Eng Sci 2016; 374:20150044. [PMID: 26903099 DOI: 10.1098/rsta.2015.0044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/25/2015] [Indexed: 06/05/2023]
Abstract
The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.
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Affiliation(s)
- E R Woolliams
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - K Anhalt
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, Berlin 10587, Germany
| | - M Ballico
- Temperature Standards, National Measurement Institute Australia (NMIA), Bradfield Road, West Lindfield, New South Wales 2070, Australia
| | - P Bloembergen
- Research Institute for Physical Measurement, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan Division of Thermophysics and Process Measurements, National Institute of Metrology (NIM), No. 18 Bei San Huan Dong Lu, Beijing 100029, People's Republic of China
| | - F Bourson
- High Temperature Metrology Department, Laboratoire commun de métrologie (LNE-Cnam), 61 rue du Landy, Saint Denis 93210, France
| | - S Briaudeau
- High Temperature Metrology Department, Laboratoire commun de métrologie (LNE-Cnam), 61 rue du Landy, Saint Denis 93210, France
| | - J Campos
- Optical Institute, Spanish National Research Council (CSIC), Serrano, 144, Madrid 28006, Spain
| | - M G Cox
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - D del Campo
- Centro Español de Metrologia, C/del Alfar, 2, Tres Cantos 28760, Spain
| | - W Dong
- Division of Thermophysics and Process Measurements, National Institute of Metrology (NIM), No. 18 Bei San Huan Dong Lu, Beijing 100029, People's Republic of China
| | - M R Dury
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - V Gavrilov
- All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Ozernaya 46, Moscow 119361, Russia
| | - I Grigoryeva
- All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Ozernaya 46, Moscow 119361, Russia
| | - M L Hernanz
- Optical Institute, Spanish National Research Council (CSIC), Serrano, 144, Madrid 28006, Spain
| | - F Jahan
- Temperature Standards, National Measurement Institute Australia (NMIA), Bradfield Road, West Lindfield, New South Wales 2070, Australia
| | - B Khlevnoy
- All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Ozernaya 46, Moscow 119361, Russia
| | - V Khromchenko
- Sensor Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - D H Lowe
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - X Lu
- Division of Thermophysics and Process Measurements, National Institute of Metrology (NIM), No. 18 Bei San Huan Dong Lu, Beijing 100029, People's Republic of China
| | - G Machin
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - J M Mantilla
- Centro Español de Metrologia, C/del Alfar, 2, Tres Cantos 28760, Spain
| | - M J Martin
- Centro Español de Metrologia, C/del Alfar, 2, Tres Cantos 28760, Spain
| | - H C McEvoy
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - B Rougié
- High Temperature Metrology Department, Laboratoire commun de métrologie (LNE-Cnam), 61 rue du Landy, Saint Denis 93210, France
| | - M Sadli
- High Temperature Metrology Department, Laboratoire commun de métrologie (LNE-Cnam), 61 rue du Landy, Saint Denis 93210, France
| | - S G R Salim
- High Temperature Metrology Department, Laboratoire commun de métrologie (LNE-Cnam), 61 rue du Landy, Saint Denis 93210, France Radiometry and Photometry Division, National Institute of Standards (NIS), PO Box 136, President Sadat Street, El-Haram, Giza, Egypt
| | - N Sasajima
- Research Institute for Physical Measurement, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - D R Taubert
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, Berlin 10587, Germany
| | - A D W Todd
- National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6, Canada
| | - R Van den Bossche
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - E van der Ham
- Temperature Standards, National Measurement Institute Australia (NMIA), Bradfield Road, West Lindfield, New South Wales 2070, Australia
| | - T Wang
- Division of Thermophysics and Process Measurements, National Institute of Metrology (NIM), No. 18 Bei San Huan Dong Lu, Beijing 100029, People's Republic of China
| | - A Whittam
- National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - B Wilthan
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, Berlin 10587, Germany
| | - D J Woods
- National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario K1A 0R6, Canada
| | - J T Woodward
- Sensor Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Y Yamada
- Research Institute for Physical Measurement, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - Y Yamaguchi
- Research Institute for Physical Measurement, National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563, Japan
| | - H W Yoon
- Sensor Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Z Yuan
- Division of Thermophysics and Process Measurements, National Institute of Metrology (NIM), No. 18 Bei San Huan Dong Lu, Beijing 100029, People's Republic of China
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Sadli M, Machin G, Anhalt K, Bourson F, Briaudeau S, del Campo D, Diril A, Kozlova O, Lowe DH, Mantilla Amor JM, Martin MJ, McEvoy HC, Ojanen-Saloranta M, Pehlivan Ö, Rougié B, Salim SGR. Dissemination of thermodynamic temperature above the freezing point of silver. Philos Trans A Math Phys Eng Sci 2016; 374:20150043. [PMID: 26903097 DOI: 10.1098/rsta.2015.0043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/05/2016] [Indexed: 06/05/2023]
Abstract
The mise-en-pratique for the definition of the kelvin at high temperatures will formally allow dissemination of thermodynamic temperature either directly or mediated through high-temperature fixed points (HTFPs). In this paper, these two distinct dissemination methods are evaluated, namely source-based and detector-based. This was achieved by performing two distinct dissemination trials: one based on HTFPs, the other based on absolutely calibrated radiation thermometers or filter radiometers. These trials involved six national metrology institutes in Europe in the frame of the European Metrology Research Programme joint project 'Implementing the new kelvin' (InK). The results have shown that both dissemination routes are possible, with similar standard uncertainties of 1-2 K, over the range 1273-2773 K, showing that, depending on the facilities available in the laboratory, it will soon be possible to disseminate thermodynamic temperatures above 1273 K to users by either of the two methods with uncertainties comparable to the current temperature scale.
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Affiliation(s)
- M Sadli
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France
| | - G Machin
- Engineering Measurement Division, National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - K Anhalt
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, Berlin 10587, Germany
| | - F Bourson
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France
| | - S Briaudeau
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France
| | - D del Campo
- Centro Español de Metrologia (CEM), C/del Alfar, 2, Tres Cantos 28760, Spain
| | - A Diril
- Tubitak Ulusal Metroloji Enstitüsü (TUBITAK UME), Gebze/Kocaeli 41400, Turkey
| | - O Kozlova
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France
| | - D H Lowe
- Engineering Measurement Division, National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - J M Mantilla Amor
- Centro Español de Metrologia (CEM), C/del Alfar, 2, Tres Cantos 28760, Spain
| | - M J Martin
- Centro Español de Metrologia (CEM), C/del Alfar, 2, Tres Cantos 28760, Spain
| | - H C McEvoy
- Engineering Measurement Division, National Physical Laboratory (NPL), Hampton Road, Teddington TW11 0LW, UK
| | - M Ojanen-Saloranta
- Thermal and Mass Metrology, VTT Technical Research Centre of Finland Ltd, Centre for Metrology MIKES, Espoo 02150, Finland
| | - Ö Pehlivan
- Tubitak Ulusal Metroloji Enstitüsü (TUBITAK UME), Gebze/Kocaeli 41400, Turkey
| | - B Rougié
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France
| | - S G R Salim
- High Temperature Metrology Department, Laboratoire Commun de Métrologie, LNE-Cnam, 61 rue du Landy, St Denis 93210, France Radiometry and Photometry Division, National Institute of Standards (NIS), President Sadat Street, El-Haram, PO Box 136, Giza, Egypt
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10
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Fellmuth B, Fischer J, Machin G, Picard S, Steur PPM, Tamura O, White DR, Yoon H. The kelvin redefinition and its mise en pratique. Philos Trans A Math Phys Eng Sci 2016; 374:20150037. [PMID: 26903103 DOI: 10.1098/rsta.2015.0037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2015] [Indexed: 06/05/2023]
Abstract
In 2018, it is expected that there will be a major revision of the International System of Units (SI) which will result in all of the seven base units being defined by fixing the values of certain atomic or fundamental constants. As part of this revision, the kelvin, unit of thermodynamic temperature, will be redefined by assigning a value to the Boltzmann constant k. This explicit-constant definition will define the kelvin in terms of the SI derived unit of energy, the joule. It is sufficiently wide to encompass any form of thermometry. The planned redefinition has motivated the creation of an extended mise en pratique ('practical realization') of the definition of the kelvin (MeP-K), which describes how the new definition can be put into practice. The MeP-K incorporates both of the defined International Temperature Scales (ITS-90 and PLTS-2000) in current use and approved primary-thermometry methods for determining thermodynamic temperature values. The MeP-K is a guide that provides or makes reference to the information needed to perform measurements of temperature in accord with the SI at the highest level. In this article, the background and the content of the extended second version of the MeP-K are presented.
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Affiliation(s)
- B Fellmuth
- Department 7.4 Temperature, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - J Fischer
- Department 7.4 Temperature, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - G Machin
- Engineering Measurement, National Physical Laboratory (NPL), Teddington, Middlesex, UK
| | - S Picard
- Bureau International des Poids et Mesures (BIPM), Sèvres, France
| | - P P M Steur
- Istituto Nazionale di Ricerca Metrologica (INRIM), Turin, Italy
| | - O Tamura
- National Metrology Institute of Japan (NMIJ), AIST, Ibaraki, Japan
| | - D R White
- Measurement Standards Laboratory of New Zealand (MSL), Lower Hutt, New Zealand
| | - H Yoon
- National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA
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11
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Underwood R, de Podesta M, Sutton G, Stanger L, Rusby R, Harris P, Morantz P, Machin G. Estimates of the difference between thermodynamic temperature and the International Temperature Scale of 1990 in the range 118 K to 303 K. Philos Trans A Math Phys Eng Sci 2016; 374:20150048. [PMID: 26903104 DOI: 10.1098/rsta.2015.0048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
Using exceptionally accurate measurements of the speed of sound in argon, we have made estimates of the difference between thermodynamic temperature, T, and the temperature estimated using the International Temperature Scale of 1990, T90, in the range 118 K to 303 K. Thermodynamic temperature was estimated using the technique of relative primary acoustic thermometry in the NPL-Cranfield combined microwave and acoustic resonator. Our values of (T-T90) agree well with most recent estimates, but because we have taken data at closely spaced temperature intervals, the data reveal previously unseen detail. Most strikingly, we see undulations in (T-T90) below 273.16 K, and the discontinuity in the slope of (T-T90) at 273.16 K appears to have the opposite sign to that previously reported.
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Affiliation(s)
- R Underwood
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - M de Podesta
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - G Sutton
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - L Stanger
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - R Rusby
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - P Harris
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - P Morantz
- School of Applied Sciences, Cranfield University, Cranfield MK43 0AL, UK
| | - G Machin
- National Physical Laboratory, Teddington TW11 0LW, UK
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12
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Vescovo E, Levick A, Childs C, Machin G, Zhao S, Williams SR. High-precision calibration of MRS thermometry using validated temperature standards: effects of ionic strength and protein content on the calibration. NMR Biomed 2013; 26:213-223. [PMID: 22961726 DOI: 10.1002/nbm.2840] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 06/27/2012] [Accepted: 07/10/2012] [Indexed: 06/01/2023]
Abstract
Currently, there is very limited ability to measure the temperature of the brain, but a direct technique for its estimation in vivo could improve the detection of patients at risk of temperature-related brain damage, help in the diagnosis of stroke and tumour, and provide useful information on the mechanisms of thermoregulation of the brain. In this article, new calibrations in vitro of MRS thermometry using temperature-stabilised reference phantoms are reported. The phantoms comprise two concentric glass spheres: the inner sphere contains the phantom material to be measured by MRS, and the outer sphere contains a substance with a known temperature stable to within 0.2 °C. The substances were freezing organic fixed-point compounds (diphenyl ether and ethylene carbonate, freezing at 26.3 and 35.8 °C, respectively) or temperature-controlled circulating water. The phantom temperature was continuously monitored with a fluoroptic probe calibrated at the National Physical Laboratory with traceability to the International Temperature Scale 1990 (ITS-90). The MRS temperature calibration was obtained by measuring the chemical shift of water relative to N-acetylaspartate (NAA) in a single voxel as a function of temperature using a 1.5-T Philips Intera scanner. Measurements were made for several phantom materials to assess the effect of tissue composition on the water-NAA chemical shift against temperature calibration. The phantom mixtures contained 25 mm of NAA buffered to pH 6.5 or 7.5 and several ionic salts or bovine serum albumin (BSA). Spectra were acquired from 25 to 45 °C. The correlation between frequency differences and phantom temperature was very linear with small residuals. However, the linear fitting parameters varied with ionic composition and BSA concentration. The 'apparent' temperature (calibrated using the water-NAA frequency differences) decreased by approximately 1 °C for every 100 mm increase in ionic concentration and increased proportionally to the concentration of BSA.
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Affiliation(s)
- E Vescovo
- Imaging, Proteomics and Genomics Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK.
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13
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Proctor L, Fitzgerald B, Whittle W, Mokhtari N, Lee E, Machin G, Kingdom J, Keating S. Umbilical cord diameter percentile curves and their correlation to birth weight and placental pathology. Placenta 2013; 34:62-6. [DOI: 10.1016/j.placenta.2012.10.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Revised: 10/22/2012] [Accepted: 10/26/2012] [Indexed: 11/29/2022]
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14
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Abstract
Significant changes in recording of human body temperature have been taking place worldwide in recent years. The clinical thermometer introduced in the mid-19th century by Wunderlich has been replaced by digital thermometers or radiometer devices for recording tympanic membrane temperature. More recently the use of infrared thermal imaging for fever screening has become more widespread following the SARS infection, and particularly during the pandemic H1N1 outbreak. Important new standards that have now reached international acceptance will affect clinical and fever screening applications. This paper draws attention to these new standard documents. They are designed to improve the standardization of both performance and practical use of these key techniques in clinical medicine, especially necessary in a pandemic influenza situation.
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Affiliation(s)
- E F J Ring
- Medical Imaging Research Unit, Faculty of Advanced Technology, University of Glamorgan, Pontypridd, CF37 1DL, UK.
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15
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Machin G, Childs C. A systematic performance evaluation of brain and body temperature sensors using ultra-stable temperature references. J Med Eng Technol 2010; 34:192-9. [PMID: 20059431 DOI: 10.3109/03091900903509156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The impact of a rise in the temperature of the human brain in patients who have suffered cerebral damage is not completely understood. Current studies are ambiguous; some show that a high brain temperature, and others a low brain temperature, is an indicator of poor prognosis. The reported effect is often very subtle, at the <0.5 degrees C level, and this may be due to the performance, or even the location of the temperature sensor. This study investigates the first of these issues, i.e. the performance of the sensor. Here performance validation is undertaken for three commonly used temperature sensors for brain and body temperature measurement, using ultra-stable temperature references. At body temperature all three sensor types performed within manufacturer's specifications. Given that only a small number of temperature sensors were tested, the indication is that, provided the sensors are located correctly, the small observed differences in temperature are real - though the issue of clinical significance is still to be addressed.
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Affiliation(s)
- G Machin
- Head of Temperature Standards, Temperature Group, National Physical Laboratory, Teddington, Middlesex, UK.
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16
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Abstract
Patient temperature is a fundamental physiological measurement used primarily for observation and diagnosis, for example during surgery, intensive care, recuperation, or treatment. A variety of thermometers are used clinically and these can be separated into two categories, either contact (oral thermometers, rectal thermometers and temporal strips), or non-contact (ear thermometers, temporal thermometers and thermal imagers). To have the maximum confidence in the clinical performance of the temperature measurement instrument it is strongly desirable that the device be traceably calibrated to the International Temperature Scale of 1990 (ITS-90). Lack of traceable calibrations accredited to ISO17025 can lead to unreliability in temperature measurement and in some cases can have a deleterious effect on patient care. The National Physical Laboratory (NPL) maintains and disseminates the ITS-90 for contact and non-contact thermometry in the UK. The importance of accredited traceable calibrations and an outline of contact and non-contact thermometry standards are given here.
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Affiliation(s)
- R Simpson
- National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW, UK.
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17
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Abstract
BACKGROUND/PURPOSE In rare instances in monochorionic twin pregnancies, one twin can have a discordant anomaly (eg, cystic hygroma). If this twin dies in utero, neurologic injury and death can occur in the surviving cotwin. To protect the normal twin, the authors developed an approach to separate the circulations and ablate the umbilical cord of the abnormal twin. METHODS From September 1998 to February 2001, 6 cases of discordant anomalous twins were diagnosed by prenatal ultrasound scan in which the anomaly was lethal or parents desired prenatal termination for this abnormal twin. All underwent surgical intervention with gestational ages varying from 19 to 24 weeks. RESULTS Depending on cord insertion site and placental anatomy, blood flow was interrupted to the anomalous fetus by either radiofrequency ablation (RFA; 2 cases), cord transection (1 case), or cord transection after laser ablation of communicating vessels (3 cases). Fetal death occurred in one normal twin 4 days postoperatively. Average age at delivery for the 5 surviving fetuses was 34.5 weeks' gestation. On follow-up, all surviving infants are neurologically intact. CONCLUSION An otherwise normal monochorionic twin threatened by an anomalous cotwin can be salvaged successfully with a strategy tailored to interrupt the vascular connections between the 2 twins.
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Affiliation(s)
- R M Sydorak
- Division of Pediatric Surgery, Department of Surgery, Fetal Treatment Center, University of California, San Francisco, CA, USA
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18
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Abstract
Outcomes of multifetal pregnancy in prenatal life are markedly affected by chorionicity. Several disease processes are found in monochorionic (MC) twins that do not occur in dichorionic (DC) twins. Improvements in prenatal outcomes will depend on reliable first trimester diagnosis of chorionicity, allowing early monitoring for complications of MC placentation. Particular structures and functions of MC twin placentas affect outcomes and can be targeted for specific treatments, especially in twin-twin transfusion. The causes of severe DC twin fetal growth discordance are clarified. In post-natal life, zygosity is a determining effect in genetic predisposition to many chronic diseases, including neoplasia. Few MC twins know that they are monozygotic (MZ). Few twin researchers realize that MZ twins may be genetically discordant. Abandonment of the word "identical" for MZ twins would assist in clarifying these issues of zygosity, concordance and discordance.
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19
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Machin G. Terminology for twin zygosity. Twin Res 2000; 3:335-6. [PMID: 11463155 DOI: 10.1375/136905200320565319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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20
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De Lia J, Fisk N, Hecher K, Machin G, Nicolaides K, Hyett J, Quintero R, Thilaganathan B, Ville Y. Twin-to-twin transfusion syndrome--debates on the etiology, natural history and management. Ultrasound Obstet Gynecol 2000; 16:210-213. [PMID: 11169283 DOI: 10.1046/j.1469-0705.2000.00266.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- J De Lia
- St Joseph's Hospital, Milwaukee, Wisconsin, USA
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Abstract
OBJECTIVE We determined the relation between newborn circumcision and both invasive penile cancer (IPC) and carcinoma in situ (CIS) among adult male members of a large health maintenance organization. SUBJECTS AND METHODS Circumcision status was ascertained by a combination of pathology reports, medical record review, and questionnaires for 213 adult male members of a large prepaid health plan who were diagnosed with IPC or CIS. RESULTS Of 89 men with IPC whose circumcision status was known, 2 (2.3%) had been circumcised as newborns, and 87 were not circumcised. Of 118 men with CIS whose circumcision status was known, 16 (15.7%) had been circumcised as newborns. CONCLUSIONS Our results confirm the highly protective effect of newborn circumcision against IPC and the less protective effect against CIS.
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Affiliation(s)
- E J Schoen
- Department of Genetics, Pediatrics, Kaiser Permanente Medical Center, Oakland, California 94611-5693, USA.
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22
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Abstract
Before one starts the hunt for quantitative trait loci (QTLs) for a complex trait, it is necessary to show that the trait is genetically influenced. This evidence is most likely to come from the classical twin study--the demonstration that monozygotic twins are more similar for the trait than dizygotic twins. The strengths and weaknesses of twin studies are discussed, and it is suggested that, far from becoming irrelevant with advances in molecular biology, they can improve the efficiency of QTL detection and play an important role in unravelling developmental genetic mechanisms.
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Affiliation(s)
- N Martin
- Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Australia.
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23
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Keith L, Machin G. Zygosity testing. Current status and evolving issues. J Reprod Med 1997; 42:699-707. [PMID: 9408868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This paper reviews the current status and evolving issues in the field of zygosity testing. Monozygotic twins are seldom absolutely identical. Traditional methods of zygosity testing, mathematical ones and assessment of physical characteristics are reviewed. The proper delineation of zygosity based on placentation and chorionicity is outlined. Genetic and environmental discordance patterns are described, with a discussion of why "identical" twins are never identical preceding specific guidelines for clinical practice.
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Affiliation(s)
- L Keith
- Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, Illinois, USA
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Abstract
Monochorionic monozygotic twins frequently suffer complications from the presence of vascular anastomoses in their monochorionic placentas. Also, sharing of perfusion zones may be unequal, leading to marked growth discordance. This paper analyzes four measures of perinatal outcome (gestational age at delivery, perinatal mortality, birth weight discordance, and presence/absence of hydramnios) according to the vascular patterns of the monochorionic placentas. The worst clinical outcomes were associated with arteriovenous anastomoses in the absence of arterio-arterial and veno-venous anastomoses. The vascular patterns of monochorionic placentas cause significant fetal environmental differences within pairs of monochorionic monozygotic twins. These differences may cause life-long discordance for several phenotypic traits that are not genetically based, and which cause monochorionic monozygotic twins to be "non-identical."
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Affiliation(s)
- G Machin
- Department of Laboratory Medicine, University of Alberta Hospitals, Edmonton, Canada
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25
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Abstract
Patterns of X-chromosome inactivation in chorion, amnion, and cord from 79 pairs of twins were examined. Seven sets of triplets were included in the analysis, both as twin pairs and triplets. Twins were stratified as dizygotic (DZ), monozygotic (MZ), monochorionic, and dichorionic and were selected for birth weight discordance, discordance for congenital anomalies, twin-twin transfusion syndrome, and various patterns of vascular anastomosis. X-inactivation was predominantly symmetric. Chorion was the most likely tissue to show asymmetric X-inactivation and was found most frequently in MZ dichorionic twins. There was no correlation of X-inactivation pattern with the selected clinical criteria. This study does not confirm that asymmetric X-inactivation in embryonic tissues is a common phenomenon in female twins, including monozygotic twins.
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Affiliation(s)
- F Bamforth
- Department of Laboratory Medicine and Pathology, University of Alberta Hospitals, Edmonton, Canada
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26
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Abstract
Zygosity testing of all multiple births allowed the identification of a subgroup of 42 monozygotic twin pairs who have dichorionic placentas, fused and separate. Perinatal outcomes of this group were compared with 110 pairs of monochorionic monozygotic twins and 148 pairs of dizygotic twins. Dichorionic monozygotic twins had the lowest incidence of preterm birth, perinatal mortality, and birth weight discordance. There was an excess of like-sexed over unlike-sexed pairs among the dizygotic twins.
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Affiliation(s)
- G Machin
- Department of Laboratory Medicine and Pathology, University of Alberta Hospitals, Edmonton, Canada
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27
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Machin G, Johnson BC, Gibson C, Rusby RL. Intercomparison of the ITS-90 Radiance Temperature Scales of the National Physical Laboratory (U.K.) and the National Institute of Standards and Technology. J Res Natl Inst Stand Technol 1994; 99:731-736. [PMID: 37404237 PMCID: PMC8345246 DOI: 10.6028/jres.099.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/29/1994] [Indexed: 07/06/2023]
Abstract
An intercomparison of radiance temperature scales has been performed by the National Physical Laboratory (NPL) and the National Institute of Standards and Technology (NIST) using a standard transfer pyrometer operating at a wavelength of approximately 1000 nm. It was found that the radiance temperature scales established by the two laboratories were in agreement to 0.1% or better of the temperature over the range 1000 °C to 2500 °C.
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Affiliation(s)
- G Machin
- The National Physical Laboratory, Queens Road, Teddington, Middlesex, TW11 OLW, United Kingdom
| | - B Carol Johnson
- National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA
| | - C Gibson
- National Institute of Standards and Technology, Gaithersburg, MD 20899-0001, USA
| | - R L Rusby
- The National Physical Laboratory, Queens Road, Teddington, Middlesex, TW11 OLW, United Kingdom
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Teixeira FJ, Zakar T, Hirst JJ, Guo F, Sadowsky DW, Machin G, Demianczuk N, Resch B, Olson DM. Prostaglandin endoperoxide-H synthase (PGHS) activity and immunoreactive PGHS-1 and PGHS-2 levels in human amnion throughout gestation, at term, and during labor. J Clin Endocrinol Metab 1994; 78:1396-402. [PMID: 8200943 DOI: 10.1210/jcem.78.6.8200943] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Prostaglandins (PGs) are of primary importance in the initiation and maintenance of labor in women. A major intrauterine source of prostaglandins is the amnion, which synthesizes increased amounts of PGE2 at term labor. Because PG endoperoxide-H synthase (PGHS) catalyzes the rate-limiting step of PG synthesis from arachidonic acid, we investigated the changes in amniotic PGHS specific activity during gestation and at term and preterm labor. Also, we determined the level of immunoreactive PGHS protein in the amnion to evaluate the mechanisms by which PGHS activity may be regulated. PGHS specific activity, measured at the amount of PGE2 produced by amnion microsomes under optimal conditions, was 18.2 +/- 3.7 pg PGE2/micrograms protein.min (mean +/- SE; n = 19) at term (37-42 weeks gestation) before the spontaneous onset of labor. PGHS specific activity was significantly higher after spontaneous term labor (38.9 +/- 6.0 pg PGE2/micrograms protein.min; n = 19; P < 0.05). Amnion samples from preterm (< 36 weeks gestation) nonlaboring patients contained low levels of PGHS specific activity (5.9 +/- 1.8 pg PGE2/micrograms protein.min; n = 9), which increased significantly with spontaneous preterm labor (28.3 +/- 6.8 pg PGE2/micrograms protein.min; n = 10; P < 0.05). Longitudinal analysis of the data showed that PGHS specific activity was low in the first and second trimesters of gestation, but increased dramatically before labor onset at term. We detected PGHS protein in all microsomal samples, with an antiovine PGHS antibody recognizing both PGHS-1 and -2 isoforms of the enzyme. However, there was no correlation between PGHS specific activity and the amount of immunoreactive PGHS protein. Using an antibody specific for PGHS-2, we detected immunoreactive protein in only 9 of the 25 tissues examined and found no correlation between PGHS specific activity and the amount of PGHS-2 protein. These results suggest that 1) PGHS specific activity in the amnion increases sharply before the onset of labor at term; 2) further increases in specific activity occur during term and preterm labor; and 3) the specific activity of PGHS in the amnion is not related directly to the amount of immunoreactive enzyme protein.
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Affiliation(s)
- F J Teixeira
- University of Alberta Perinatal Research Center, Department of Obstetrics and Gynecology, Edmonton, Canada
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29
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Stroman PW, Allen PS, Lien DC, Machin G, Man SF. Evaluation of effects of PAF on alveolar fluid clearance with use of NMR imaging. J Appl Physiol (1985) 1993; 75:1930-7. [PMID: 8307842 DOI: 10.1152/jappl.1993.75.5.1930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Autologous serum with or without platelet-activating factor (PAF) was instilled into one lung lobe of an anesthetized cat, and changes in the regional lung water content were monitored for 4 h with proton nuclear magnetic resonance (NMR) images and relaxation time measurements. With serum as an instillate, water was cleared with a half time of approximately 670 min; after 4 h, 86 +/- 6% of that instilled remained. With PAF added to the instillate, clearance was biphasic with an initial clearance half time of approximately 30 min followed by clearance similar to that observed after serum instillation; after 4 h, 35 +/- 4% of that instilled remained. In contrast, 4 h after instillation of serum or serum plus PAF, 91 +/- 3% and 82 +/- 5%, respectively, of the instilled 125I-labeled albumin remained in the lung (P = 0.06). From transverse magnetization relaxation curves we were able to resolve two relaxation components, which we have attributed to the instilled fluid in the air spaces (relaxation time = 177 +/- 7 ms) and the tissue-bound fluid (relaxation time = 25 +/- 1 ms).
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Affiliation(s)
- P W Stroman
- Department of Applied Sciences in Medicine, University of Alberta, Edmonton, Canada
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30
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Teixeira FJ, Zakar T, Hirst J, Guo F, Machin G, Olson DM. Prostaglandin endoperoxide H synthase (PGHS) activity increases with gestation and labour in human amnion. J Lipid Mediat 1993; 6:515-23. [PMID: 8358011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- F J Teixeira
- Department of Physiology, University of Alberta, Edmonton, Canada
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31
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Lemke RP, Machin G, Muttitt S, Bamforth F, Rao S, Welch R. A case of aplasia cutis congenita in dizygotic twins. J Perinatol 1993; 13:22-7. [PMID: 8445443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We report a newborn infant with extensive aplasia cutis congenita of the flanks and thighs, associated with a co-twin fetus papyraceus. DNA restriction fragment polymorphism analysis of the twins proved dizygosity. The association of these two conditions in twins is reviewed.
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Affiliation(s)
- R P Lemke
- Department of Pediatrics, University of Alberta Hospital, Edmonton, Canada
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32
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Abstract
We describe a female infant with apparent Poland anomaly (PA) and limb body wall defect. Analysis of the defects suggest that a disruption of the lateral embryonic plate mesoderm may have been responsible for the observed lesions. Because of the overlap of this case with PA, we re-examined previous reports of this syndrome. We think that the lesions could be equally well explained as a mesodermal disruption, and point out a previously unrecognised discrepancy between sex and affected side in sporadic PA and inherited PA which supports this view.
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Affiliation(s)
- J S Bamforth
- Department of Paediatrics, University of Alberta, Edmonton, Canada
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van Paradijs J, Allington-Smith J, Callanan P, Charles PA, Hassall BJM, Machin G, Mason KO, Naylor T, Smale AP. Optical observations of the eclipsing binary radio pulsar PSR1957 + 20. Nature 1988. [DOI: 10.1038/334684a0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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McMillan DD, Rademaker AW, Buchan KA, Reid A, Machin G, Sauve RS. Benefits of orotracheal and nasotracheal intubation in neonates requiring ventilatory assistance. Pediatrics 1986; 77:39-44. [PMID: 3940358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
To investigate differences in orotracheal (OT) and nasotracheal (NT) intubation for ventilatory assistance, we randomly assigned 91 neonates to be intubated via either of the two routes: 46 infants were assigned to the OT group and 45 infants were assigned to the NT group. Inability to intubate the nostril in three neonates, and respiratory or cardiac instability during attempted NT intubation in three neonates, resulted in the assignment of 52 infants to the OT group and 39 infants to the NT group; patients in both groups were of comparable size, sex, and clinical problems. Initial malposition of the endotracheal tube and need to retape, reposition, or replace the tube during the mean duration of intubation of 247 +/- 42 hours for the OT group and 273 +/- 57 hours for the NT group were similar. Daily Gram stains of tracheal aspirates showed that inflammation (greater than or equal to ten polymorphonuclear cells per 400 power fields) was common (51% OT group, 53% NT group). Cultures grew potential pathogens in 37% of the patients from the OT group and 31% of the NT group. There was no difference in the clinical or radiologic incidence of pneumonia. Postextubation problems were comparable: atelectasis, 48% OT and 59% NT; stridor, 15% OT and 26% NT. OT intubation may be preferred for prolonged ventilatory assistance in neonates because of the relative ease of initial intubation.
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Abstract
Fetal echocardiography as a tool for the prenatal diagnosis of cardiac structural abnormalities was utilized in 27 consecutive patients who were referred for evaluation. Four abnormalities were recognized prenatally and confirmed postnatally. A fifth was identified postnatally. The sensitivity and specificity of this diagnostic test were 80% and 100%, respectively. The utilization of this tool in a tertiary care setting by an adequately trained team has proved to be helpful and is recommended.
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Abstract
This retrospective study examined the effects of very prolonged membrane rupture of more than 1 week on the development of pulmonary hypoplasia and positional deformities in the infants of 100 consecutive women. A control group of infants who were matched for gestational age at delivery, sex, and time of delivery was identified. The results indicate that there was a statistically significant difference (p less than 0.001) in the occurrence of pulmonary hypoplasia and positional deformities. The greatest impact of prolonged membrane rupture on fetal development was seen in the patients in whom membrane rupture occurred prior to 26 weeks' gestation and the duration of rupture was more than 5 weeks.
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Kleinstiver S, Boyd N, Machin G, Trevenen C. Simultaneous duplicate sweat analysis using the Gibson & Cooke and the Webster techniques. Clin Biochem 1983. [DOI: 10.1016/s0009-9120(83)80087-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
The muscles of four infants with cerebro-hepato-renal (Zellweger) syndrome were studied during life and/or at necropsy. A mitochondrial myopathy was demonstrated, similar to mitochondrial alterations demonstrated in liver and brain in this disease. Muscle fibers with red-staining subsarcolemmal aggregates were identified with Gomori trichrome stain in two cases. Subsarcolemmal and intermyofibrillar zones of increased concentrations of NADH-TR, SDH, and cytochrome-c-oxidase activity were demonstrated histochemically in all four cases. Degenerative and cytoarchitectural changes in muscle fibers were not found. Ultrastructural studies showed large aggregates of mitochondria and increased lipid in the subsarcolemmal and intermyofibrillar spaces. Degenerative changes in mitochondria and lipid also were demonstrated, but paracrystalline inclusions were not seen. The distribution of these changes was not uniform between patients or between different muscles in the same patient. The diaphragm was affected more severely than proximal or distal muscles of the extremities. Direct involvement of muscle mitochondria in this disease may interfere with energy metabolism and contribute to the clinical findings of hypotonia, weakness, and respiratory insufficiency. The muscle biopsy with histochemistry and electron microscopy may be used as a diagnostic adjunct in suspected cases, but the variation encountered dictates dictates caution in the interpretation of negative findings.
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