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Kitakule MM, Mayo P. Use of Ultrasound to Assess Fluid Responsiveness in the Intensive Care Unit~!2009-04-15~!2009-06-02~!2010-07-15~! ACTA ACUST UNITED AC 2010. [DOI: 10.2174/1874828701003020033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mayo P, Ródenas F, Verdu G, Campayo JM, Gallardo S. Analysis of image quality parameter of conventional and dental radiographic digital images. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2010:3174-3177. [PMID: 21096597 DOI: 10.1109/iembs.2010.5627182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The image quality obtained by a radiographic equipment is very useful to characterize the physical properties of the image radiographic chain, in a quality control of the radiographic equipment. In the radiographic technique it is necessary that the evaluation of the image can guarantee the constancy of its quality to carry out a suitable diagnosis. In this work we have designed some radiographic phantoms for different radiographic digital devices, as dental, conventional, equipments with computed radiography (phosphor plate) and direct radiography (sensor) technology. Additionally, we have developed a software to analyse the image obtained by the radiographic equipment with digital processing techniques, as edge detector, morphological operators, statistical test for the detected combinations‥ The design of these phantoms let the evaluation of a wide range of operating conditions of voltage, current and time of the digital equipments. Moreover, the image quality analysis by the automatic software, let study it with objective parameters.
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Mayo P, Rodenas F, Campayo JM, Pascual A, Marín B, Verdú G. Image Quality Assessment of Digital Dental Radiography Systems with Specifically Developed Phantom and Software. NUCL TECHNOL 2009. [DOI: 10.13182/nt09-a9133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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54
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Mayo P, Rodenas F, Campayo JM, Pascual A, Marín B, Verdú G. Phantom Development for Constancy and Acceptance Test for Digital Radiographic Equipment. NUCL TECHNOL 2009. [DOI: 10.13182/nt09-a9132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Mayo P, Rodenas F, Verdú G, Campayo JM, Villaescusa JI. Analysis of digital image quality indexes for CIRS SP01 and CDMAM 3.4 mammographic phantoms. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2009; 2008:418-21. [PMID: 19162682 DOI: 10.1109/iembs.2008.4649179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Mammographic phantom images are usually used to study the quality of images obtained by determined mammographic equipment. The digital image treatment techniques allow carrying out an automatic analysis of the phantom image. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. In this work we apply some techniques of digital image processing to compute a specific image quality indexes for mammographic phantoms, namely CIRS SP01 and CDMAM 3.4. to study the evolution of this parameter with different varying conditions of the mammographic equipment. The indexes are calculated from a scoring system based on a designed algorithm which analyses the phantom image by means of an automatic detection of the test objects in each phantom.
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Fukunaga M, Barnes J, Lakticova V, Seres D, Mayo P. SELENIUM DEFICIENCY INDUCED CARDIOMYOPATHY IN A PATIENT WITH A HISTORY OF GASTRIC BYPASS SURGERY. Chest 2008. [DOI: 10.1378/chest.134.4_meetingabstracts.c2002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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57
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Mayo P, Rodenas F, Verdú G, Campayo JM, Villaescusa JI. Study of digital mammographic equipments by phantom image quality. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:1994-6. [PMID: 17946081 DOI: 10.1109/iembs.2006.259245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast-detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is CDMAM 3.4. One of the most extended indexes to measure the image quality in an objective way is the image quality figure (IQF). The aim of this work is to study the image quality of different images contrast-detail phantom CDMAM 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments that facilitates the evaluation of image contrast and detail resolution.
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Gavi E, Eisen L, Mayo P. UTILITY OF AN ULTRASOUND-BASED ALGORITHM FOR RAPID RESPONSE TEAMS IN THE EVALUATION OF ACUTE DYSPNEA. Chest 2007. [DOI: 10.1378/chest.132.4_meetingabstracts.567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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59
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Poelaert J, Mayo P. Education and evaluation of knowledge and skills in echocardiography: how should we organize? Intensive Care Med 2007; 33:1684-6. [PMID: 17701397 DOI: 10.1007/s00134-007-0802-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Accepted: 07/07/2007] [Indexed: 10/23/2022]
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60
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Mayo P, Rodenas F, Ginestar D, Verdu G. Nonlinear diffusion, negentropy and restoration of mammographic images. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2005:6587-90. [PMID: 17281780 DOI: 10.1109/iembs.2005.1616010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Diffusive iterative filtering may be used to restore mammographic noisy images. Assuming that images are corrupted by additive gaussian noise, the negentropy as a statistical measure of the nongaussianity, can be used to estimate the amount of noise removed from noisy images. In particular, the evolution of the negentropy with the iterations is used to introduce a stopping criterion to end the diffusive filtering process. Because of computational complexity of the negentropy function, it is estimated by using an approximation of the negentropy introduced by Hyvärinen in the context of independent component analysis.
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Mayo P, Rodenas F, Verdú G. Comparing methods to denoise mammographic images. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2006:247-50. [PMID: 17271656 DOI: 10.1109/iembs.2004.1403138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Digital mammographic image processing often requires a previous application of filters to reduce the noise level of the image while preserving important details. This may improve the quality of digital mammographic images and contribute to an accurate diagnosis. In the literature, one can find a large amount of denoising techniques available for different kinds of images. We have adapted some of the existing denoising algorithms to mammographic images. We compare the effect of different denoising filters acting on digitized mammograms. The considered filters are: a local Wiener filter, a wavelet filter, a filter based on independent component analysis, and finally, a filter based on the diffusion equation. The noise reduction is measured by the mean squared error.
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Eisen LA, Minami T, Sekiguchi H, Berger JS, Mayo P, Narasimhan M. ULTRASOUND DEMONSTRATION OF ASYMMETRY BETWEEN THE LEFT AND RIGHT FEMORAL AND RADIAL ARTERIES. Chest 2006. [DOI: 10.1378/chest.130.4_meetingabstracts.201s-a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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63
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Zhu Y, Kuhn T, Mayo P, Hinds WC. Comparison of daytime and nighttime concentration profiles and size distributions of ultrafine particles near a major highway. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2006; 40:2531-6. [PMID: 16683588 DOI: 10.1021/es0516514] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Previously we have conducted systematic measurements of the concentration and size distribution of ultrafine particles in the vicinity of major highways during daytime in Los Angeles. The present study compares these with similar measurements made at night. Particle number concentration was measured by a condensation particle counter (CPC) and size distributions in the size range from 7 to 300 nm were measured by a scanning mobility particle sizer (SMPS). Measurements were taken at 30, 60, 90, 150, and 300 m upwind and downwind from the center of the 1-405 freeway. Average traffic flow at night was about 25% of that observed during the day. Particle number concentration measured at 30 m downwind from the freeway was 80% of previous daytime measurements. This discrepancy between changes in traffic counts and particle number concentrations is apparently due to the decreased temperature, increased relative humidity, and lower wind speed at night. Particle size distributions do not change as dramatically as they did during the daytime. Particle number concentration decays exponentially downwind from the freeway similarly to what was observed during the day, but at a slower rate. No particle number concentration gradient has been observed for the upwind side of the freeway. No PM2.5 and very weak PM10 concentration gradients were observed downwind of thefreeway at night. Ultrafine particle number concentration measured at 300 m downwind from the freeway was still distinguishably higher than upwind background concentration at night. These data may be used to help estimate exposure to ultrafine particles in the vicinity of major highways for epidemiology studies.
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Mayo P, Rodenas F, Ginestar D, Verdú G, Miró R. Diffusion equations with negentropy applied to denoise mammographic images. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2006; 2006:4751-4754. [PMID: 17946261 DOI: 10.1109/iembs.2006.259489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Mammography is a radiographic technique used for the detection of breast lesions. The analysis of the digital image normally requires a previous application of filters as a preprocessing step to reduce the noise level of the image, while preserving important details to carry out a suitable diagnostic. In the literature, there are a large amount of denoising techniques applied to different medical images. In this work we have studied the performance of a diffusive filter with a stopping condition based on the statistical concept of negentropy, applied to denoise mammographic images. The negentropy has been succesfully prove with other denoising methods as independent component analysis by the authors in [1]. We have evaluated the final image quality obtained, measuring a root mean squared error between the noise-free initial image and the final restored image and compared the results obtained by this diffusive filter with those obtained by an adaptative non-linear Wiener filter.
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Minami T, Eisen L, Berger J, Narasimhan M, Mayo P. GENDER DISPARITY IN FAILURE RATE FOR ARTERIAL CATHETER ATTEMPTS. Chest 2005. [DOI: 10.1378/chest.128.4_meetingabstracts.194s] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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66
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Shiu KK, Rosen MJ, Mayo P. A SENSITIVITY ANALYSIS OF TUBE THORACOSTOMY FAILURE IN PLEURAL EFFUSION APPLICATIONS. Chest 2005. [DOI: 10.1378/chest.128.4_meetingabstracts.322s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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67
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Mayo P, Rodenas F, Verdú G, Villaescusa JI, Campayo JM. A comparative study of computer assisted assessment of image quality index for mammographic phantom images. RADIATION PROTECTION DOSIMETRY 2005; 116:620-3. [PMID: 16604712 DOI: 10.1093/rpd/nci222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Mammographic phantom images are usually used to study the quality of images obtained by dedicated mammographic equipment. The digital image treatment techniques allow us to carry out an automatic analysis of the phantom image. In this work, some techniques of digital image processing are applied to compute a specific image quality index (IQI) for a mammographic phantom, namely CIRS model 11A version SP01. The algorithm designed analyses the phantom image by means of automatic detection of the number of microcalcifications, and the image resolution as the number of line pairs per millimetre. Then, the IQI is calculated from a scoring system. The manner in which the functioning conditions (kV and mAs) of the mammographic equipment and the preprocessing denoising method of the digital image affect the results for the IQI are also studied.
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Adachi M, Rosenthal M, Mueck J, Ribaudo V, Schneider R, Mayo P. Achieving Housestaff Competence in Emergency Airway Management: Standard Training Versus Training Using a Computerized Patient Simulator. Chest 2004. [DOI: 10.1378/chest.126.4_meetingabstracts.871s-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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69
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Mayo P, Rodenas F, Verdú G, Villaescusa JI, Campayo JM. Automatic evaluation of the image quality of a mammographic phantom. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2004; 73:115-128. [PMID: 14757255 DOI: 10.1016/s0169-2607(03)00023-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In this work a method has been developed to analyse the digital image quality of a mammographic phantom by means of automatic process techniques. The techniques used for the digital image treatment are standard techniques as the image thresholding to detect objects, the regional growing for pixels pooling and the morphological operator application to determine the objects shape and size, etc. This study allows the obtention of information about the phantom characteristics, that due to its small size and lowly contrast can be obtained very difficultly by direct observation. The final aim of this work is to obtain one or more parameters to characterize the reference phantom quality image in an objective way. These parameters will serve to compare images obtained at different mammographic centers and also, to study the temporal evolution of the image quality produced by determined mammographic equipment.
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Shakespeare E, Won C, Matsubayashi T, Murashige N, Sundaram S, Mayo P. The Effect of Flexible Bronchoscopy on End-Expiratory Lung Volumes in Intubated Patients on Mechanical Ventilatio. Chest 2003. [DOI: 10.1378/chest.124.4_meetingabstracts.78s] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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71
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Mayo P, Orlova G, Goddard JD, Tam W. Remote substituent effects on the oxymercuration of 2-substituted norbornenes: an experimental and theoretical study. J Org Chem 2001; 66:5182-91. [PMID: 11463272 DOI: 10.1021/jo010330h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effect of a remote substituent on regioselectivity in the oxymercuration of 2-substituted norbornenes has been investigated experimentally and theoretically using density functional theory (DFT). Regioselectivities of 1:1 to 14:1 were observed with various 2-substituted norbornenes. Exo-2-substituted norbornenes always gave greater regioselectivities compared to the corresponding endo-2-substituted norbornenes. The effects of solvents on the regioselectivity have also been examined, and ethereal solvents were found to be the best choice giving the optimal yield and regioselectivity. The relative rate of oxymercuration was estimated by competition experiments. The least reactive substrate (X = OAc) gave the highest regioselectivity. According to DFT predictions, the increased difference between the reaction barriers that results in the greater regioselectivity is correlated directly with the larger polarity of the C=C double bond, which is attacked by the mercury and oxygen. A number of stable exo and endo conformers were predicted. All exo conformers show the same polarity of the double bond, while some endo conformers have a reversal of this polarity. All the conformers except those with the OAc substituent are very close in energy and thus should react. The existence of a mixture of endo conformers with the C=C double bond of opposite polarity clearly explains a decrease in regioselectivity for the endo species. The origin of the greatest regioselectivity for the OAc-2-norbornenes lies in the fact that the conformer with the largest polarity is notably lower in energy than others due to an internal C-H-O hydrogen bond.
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72
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Vasconez HC, Donnelly MB, Mayo P, Schwartz RW. Student perceptions of the effectiveness of a problem-based surgery curriculum. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 1993; 68:S28-S30. [PMID: 8216623 DOI: 10.1097/00001888-199310000-00036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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73
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Hays H, Mayo P. A single case study using high-dose hydromorphone to control severe pain and serial psychometric testing to assess effects. J Pain Symptom Manage 1993; 8:173-6. [PMID: 7686955 DOI: 10.1016/0885-3924(93)90146-m] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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74
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75
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Hays H, Mayo P. A single case study using high dose hydromorphone to control severe chronic pain and serial psychometric testing to assess effects. Pain 1990. [DOI: 10.1016/0304-3959(90)92481-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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