Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23121
G. Gaudette, J. Todaro, E. Azeloglu, I. Krukenkamp, F. Chiang
The determination of regional function in the beating heart necessitates a technique to measure local deformation with high spatial resolution. We have previously reported the ability of computer aided speckle interferometry (CASI) to accurately determine deformation in the non-beating heart. Herein we use this technique to ascertain regional deformation allowing for the determination of regional area-left ventricular pressure loops, also known as regional stroke work. An isolated rabbit heart was placed in a modified Langendorff apparatus that allowed the left ventricle to develop pressure and eject volume into the aorta. CASI was used to determine the simultaneous deformation of over 900 points located in a region approximately 4 × 6 mm on the anterior surface of the left ventricle. The heart was then subjected to regional ischemia and data were again acquired. Over the whole region, the average regional stroke work decreased at both 2 and 5 minutes of regional ischemia, which partially recovered upon reperfusion. In addition, this region was subdivided into 24 areas, and regional stroke work was determined in each area and similar results to that obtained over the whole region were found.
{"title":"Determination of Regional Stroke Work With High Spatial Resolution in the Isolated Beating Rabbit Heart","authors":"G. Gaudette, J. Todaro, E. Azeloglu, I. Krukenkamp, F. Chiang","doi":"10.1115/imece2001/bed-23121","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23121","url":null,"abstract":"\u0000 The determination of regional function in the beating heart necessitates a technique to measure local deformation with high spatial resolution. We have previously reported the ability of computer aided speckle interferometry (CASI) to accurately determine deformation in the non-beating heart. Herein we use this technique to ascertain regional deformation allowing for the determination of regional area-left ventricular pressure loops, also known as regional stroke work. An isolated rabbit heart was placed in a modified Langendorff apparatus that allowed the left ventricle to develop pressure and eject volume into the aorta. CASI was used to determine the simultaneous deformation of over 900 points located in a region approximately 4 × 6 mm on the anterior surface of the left ventricle. The heart was then subjected to regional ischemia and data were again acquired. Over the whole region, the average regional stroke work decreased at both 2 and 5 minutes of regional ischemia, which partially recovered upon reperfusion. In addition, this region was subdivided into 24 areas, and regional stroke work was determined in each area and similar results to that obtained over the whole region were found.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87839830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23026
T. L. Moore, L. Gibson
Microdamage, in the form of small cracks, exists in healthy bone. Microdamage can be created by an overload or by repetitive motion (fatigue) during daily activities. Usually, microdamage is repaired during bone remodeling and a steady state is maintained. However, in cases of excessive microdamage creation or slowed bone remodeling, microdamage can coalesce to create a fracture. Our previous work [1,2] has investigated microdamage accumulation with increasing strain in bovine trabecular bone loaded in monotonic compression and compressive fatigue. Specimens fatigued at relatively high load levels fail after a few loading cycles, while specimens fatigued at lower load levels may undergo thousands of cycles before failure. During high cycle fatigue, microdamage may accumulate by the growth of pre-existing microcracks, as well as by the crack initiation seen in low cycle fatigue.
{"title":"The Effect of Number of Cycles on Microdamage Accumulation in Bovine Trabecular Bone","authors":"T. L. Moore, L. Gibson","doi":"10.1115/imece2001/bed-23026","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23026","url":null,"abstract":"\u0000 Microdamage, in the form of small cracks, exists in healthy bone. Microdamage can be created by an overload or by repetitive motion (fatigue) during daily activities. Usually, microdamage is repaired during bone remodeling and a steady state is maintained. However, in cases of excessive microdamage creation or slowed bone remodeling, microdamage can coalesce to create a fracture. Our previous work [1,2] has investigated microdamage accumulation with increasing strain in bovine trabecular bone loaded in monotonic compression and compressive fatigue. Specimens fatigued at relatively high load levels fail after a few loading cycles, while specimens fatigued at lower load levels may undergo thousands of cycles before failure. During high cycle fatigue, microdamage may accumulate by the growth of pre-existing microcracks, as well as by the crack initiation seen in low cycle fatigue.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86653173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23042
A. Patwardhan, J. Simonds, A. Ghanayem, L. Voronov, Arif Ali, S. Hodges, O. Paxinos, R. Havey, F. Phillips, T. Gavin, K. Meade
Spondylolisthesis is defined as a slippage of a vertebral body on the one below. Isthmic spondylolisthesis, caused by stress fracture or a developmental anomaly at the pars interarticularis, is the most common type of lumbar spondylolisthesis with a 6% incidence in adults. Isthmic lumbar spondylolisthesis is a frequent cause of disabling low-back and leg pain. The goal of this study is to improve the quality of treatment of these patients.
{"title":"An Experimental Model of Adult-Onset Slip Progression in Isthmic Spondylolisthesis","authors":"A. Patwardhan, J. Simonds, A. Ghanayem, L. Voronov, Arif Ali, S. Hodges, O. Paxinos, R. Havey, F. Phillips, T. Gavin, K. Meade","doi":"10.1115/imece2001/bed-23042","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23042","url":null,"abstract":"\u0000 Spondylolisthesis is defined as a slippage of a vertebral body on the one below. Isthmic spondylolisthesis, caused by stress fracture or a developmental anomaly at the pars interarticularis, is the most common type of lumbar spondylolisthesis with a 6% incidence in adults. Isthmic lumbar spondylolisthesis is a frequent cause of disabling low-back and leg pain. The goal of this study is to improve the quality of treatment of these patients.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89136511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23013
E. Finol, C. Amon
Abdominal Aortic Aneurysms (AAAs) are balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. The mean age of patients with AAA is 67 years and males are affected more often than women in a ratio of 4:1. Abdominal aortic aneurysm rupture is the 13th leading cause of death in the United States, affecting 1 in 250 individuals greater than 50 years of age. AAAs usually remain asymptomatic while slowly enlarging over a period of years or even decades. Factors that are known to affect the risk of aneurysm rupture are: maximum transverse dimension of the aneurysm, its expansion rate, its relative size compared to the patient’s body size, smoking, and family history of the patient. The five-year survival rate is only 19% and the overall mortality rate following rupture may exceed 90% [1]. Therefore, aneurysm screening and determination of the factors that may have an important role in aneurysm growth and rupture have become important elements in the investigation of this clinical problem.
{"title":"Secondary Flow and Wall Shear Stress in Three-Dimensional Steady Flow AAA Hemodynamics","authors":"E. Finol, C. Amon","doi":"10.1115/imece2001/bed-23013","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23013","url":null,"abstract":"\u0000 Abdominal Aortic Aneurysms (AAAs) are balloon-shaped expansions commonly found in the infrarenal segment of the abdominal aorta, between the renal arteries and the iliac bifurcation. The mean age of patients with AAA is 67 years and males are affected more often than women in a ratio of 4:1. Abdominal aortic aneurysm rupture is the 13th leading cause of death in the United States, affecting 1 in 250 individuals greater than 50 years of age. AAAs usually remain asymptomatic while slowly enlarging over a period of years or even decades. Factors that are known to affect the risk of aneurysm rupture are: maximum transverse dimension of the aneurysm, its expansion rate, its relative size compared to the patient’s body size, smoking, and family history of the patient. The five-year survival rate is only 19% and the overall mortality rate following rupture may exceed 90% [1]. Therefore, aneurysm screening and determination of the factors that may have an important role in aneurysm growth and rupture have become important elements in the investigation of this clinical problem.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78890060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23155
K. Barbee, Amit Bhavnani
Over 350,000 percutaneous translumenal coronary angioplasty (balloon angioplasty) procedures are performed each year. This procedure offers a less invasive alternative to coronary by-pass surgery for patients whose coronary vessels have become occluded due to the process of atherosclerosis. Its potential has not been fully realized due to the high rate of restenosis — the rapid reocclusion of the vessel due to the pathological growth of the vascular smooth muscle (VSM) in response to the trauma of the balloon inflation. Despite the recognition of smooth muscle injury as an initiating event in the process of restenosis, there has been no systematic study to determine the mechanical loading conditions required to produce VSM injury and elicit the restenosis response. In this study, a cell culture model was developed to define the loading conditions required to produce VSM injury. The model system allows precise control of the applied strain and strain rate and quantification of the injury severity in terms of membrane damage. The determination of the threshold criteria for cell injury will allow the angioplasty procedure to be modified, and possibly automated, to minimize VSM injury and avoid the restenosis response.
{"title":"Strain and Strain Rate Dependence of Vascular Smooth Muscle Injury","authors":"K. Barbee, Amit Bhavnani","doi":"10.1115/imece2001/bed-23155","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23155","url":null,"abstract":"\u0000 Over 350,000 percutaneous translumenal coronary angioplasty (balloon angioplasty) procedures are performed each year. This procedure offers a less invasive alternative to coronary by-pass surgery for patients whose coronary vessels have become occluded due to the process of atherosclerosis. Its potential has not been fully realized due to the high rate of restenosis — the rapid reocclusion of the vessel due to the pathological growth of the vascular smooth muscle (VSM) in response to the trauma of the balloon inflation. Despite the recognition of smooth muscle injury as an initiating event in the process of restenosis, there has been no systematic study to determine the mechanical loading conditions required to produce VSM injury and elicit the restenosis response. In this study, a cell culture model was developed to define the loading conditions required to produce VSM injury. The model system allows precise control of the applied strain and strain rate and quantification of the injury severity in terms of membrane damage. The determination of the threshold criteria for cell injury will allow the angioplasty procedure to be modified, and possibly automated, to minimize VSM injury and avoid the restenosis response.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86118239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23016
N. Genes, Matthew D. Silva, C. Sotak, L. Bonassar
Alginate in solution is crosslinked in the presence of multivalent cations, making it a useful polymer for drug delivery and tissue engineering. The degree of crosslinking depends on the concentration (Rowley 2000) and chemical identity of the crosslinker (Seely 1974).
{"title":"Cell Adhesion to RGD-Alginate Is Modulated by Substrate Mechanics","authors":"N. Genes, Matthew D. Silva, C. Sotak, L. Bonassar","doi":"10.1115/imece2001/bed-23016","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23016","url":null,"abstract":"\u0000 Alginate in solution is crosslinked in the presence of multivalent cations, making it a useful polymer for drug delivery and tissue engineering. The degree of crosslinking depends on the concentration (Rowley 2000) and chemical identity of the crosslinker (Seely 1974).","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91485557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23022
D. Vashishth, Winson T. George, Jennifer Smith, J. Brunski, L. Ostrander
In contrast to the traditional classroom environment that promotes passive learning, the multimedia-based studio approach is considered to be a more effective tool for delivering course content as it increases active in-class involvement, teamwork experience and cooperative learning (Wilson 1994). More significantly, the studio environment provides a plethora of opportunities to include case studies that promote hands-on experience and problem-solving, illustrate real-life problems and increase student interest in the course content (Starrett and Morcos 2001). In general, engineering courses benefit from the availability of simulation and analysis software in a multimedia studio environment. Biomedical engineering courses including biomechanics, however, are not always amenable to simulation and often require the setting of complicated and expensive tests involving human subjects and hazardous materials. Furthermore, unlike traditional medical courses, biomedical engineering departments do not have extensive teaching laboratories and students have little or no clinical exposure.
{"title":"Hands-on Approaches to Biomechanics Education in a Technologically Connected Classroom","authors":"D. Vashishth, Winson T. George, Jennifer Smith, J. Brunski, L. Ostrander","doi":"10.1115/imece2001/bed-23022","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23022","url":null,"abstract":"\u0000 In contrast to the traditional classroom environment that promotes passive learning, the multimedia-based studio approach is considered to be a more effective tool for delivering course content as it increases active in-class involvement, teamwork experience and cooperative learning (Wilson 1994). More significantly, the studio environment provides a plethora of opportunities to include case studies that promote hands-on experience and problem-solving, illustrate real-life problems and increase student interest in the course content (Starrett and Morcos 2001). In general, engineering courses benefit from the availability of simulation and analysis software in a multimedia studio environment. Biomedical engineering courses including biomechanics, however, are not always amenable to simulation and often require the setting of complicated and expensive tests involving human subjects and hazardous materials. Furthermore, unlike traditional medical courses, biomedical engineering departments do not have extensive teaching laboratories and students have little or no clinical exposure.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81639278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23100
K. Friedman
The determination of the relationship of the upper and lower Hybrid III dummy neck transducer loads during vertical drop test loading was of interest in the present study. The anthropometric test device is a tool used in crash analysis. It is typically used for frontal or side crash analysis. It has however been used for vertical drop or rollover studies (1).
{"title":"Comparison of Upper and Lower Hybrid III Dummy Neck Compression Forces Under Vertical Loading","authors":"K. Friedman","doi":"10.1115/imece2001/bed-23100","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23100","url":null,"abstract":"\u0000 The determination of the relationship of the upper and lower Hybrid III dummy neck transducer loads during vertical drop test loading was of interest in the present study. The anthropometric test device is a tool used in crash analysis. It is typically used for frontal or side crash analysis. It has however been used for vertical drop or rollover studies (1).","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90862739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23054
M. Koff, T. Gardner, E. Balaguer, C. Kawcak, C. McIlwraith, V. Mow
Osteochondral diseases occur within ail bones and cartilages of the equine carpus and can lead to loss of athletic use and occasionally catastrophic injury that necessitate euthanasia. The intensity and direction of stresses that lead to such injuries are unknown. Joint modeling is a commonly used technique in human orthopaedic research that allows investigators to determine the internal stresses of joints. Through the use of computer models, various scenarios, such as ligament damage, can be simulated and changes in the resulting joint surface stresses determined [1]. The purpose of this study was to experimentally obtain precise quantitative contact area data of the articular surfaces of the distal radius, the proximal and distal aspects of the radial carpal bone and the proximal aspect of the 3rd carpal bone of the equine carpus. These data provide normative contact and cartilage thickness values for the equine carpus that will facilitate the use of this joint as a large animal model for osteoarthritis studies. Furthermore, these experimental data will serve as the basis for the development and calibration of an equine carpus whole joint computer model.
{"title":"Precise Quantitative Models of the Equine Articular Carpus Anatomy and Contact Areas","authors":"M. Koff, T. Gardner, E. Balaguer, C. Kawcak, C. McIlwraith, V. Mow","doi":"10.1115/imece2001/bed-23054","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23054","url":null,"abstract":"\u0000 Osteochondral diseases occur within ail bones and cartilages of the equine carpus and can lead to loss of athletic use and occasionally catastrophic injury that necessitate euthanasia. The intensity and direction of stresses that lead to such injuries are unknown. Joint modeling is a commonly used technique in human orthopaedic research that allows investigators to determine the internal stresses of joints. Through the use of computer models, various scenarios, such as ligament damage, can be simulated and changes in the resulting joint surface stresses determined [1]. The purpose of this study was to experimentally obtain precise quantitative contact area data of the articular surfaces of the distal radius, the proximal and distal aspects of the radial carpal bone and the proximal aspect of the 3rd carpal bone of the equine carpus. These data provide normative contact and cartilage thickness values for the equine carpus that will facilitate the use of this joint as a large animal model for osteoarthritis studies. Furthermore, these experimental data will serve as the basis for the development and calibration of an equine carpus whole joint computer model.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87787578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/bed-23158
C. Baicu, M. Zile
Pathological processes which cause diastolic congestive heart failure (CHF), such as pressure overload hypertrophy (POH), produce abnormalities in the material properties of cardiac muscle cells (cardiomyocytes) and may selectively alter its elastic stiffness, viscosity, or both. Previous methods used to characterize these cardiomyocyte viscoelastic properties were constrained by specific biological and engineering limitations, which prevented testing in conditions that mimic normal physiology. The current study proposes an uniaxial variable-rate stretching method, in which isolated cardiomyocytes embedded in a three-dimensional gel matrix were subjected to stretch. Physiological Ca++ (2.5 mM) and rapid stretch rates up to 100 μm/sec provided experimental conditions parallel to in vivo physiology. The proposed method identified and individually quantified both cellular stiffness and viscosity, and showed that POH increased both elastic and viscous cardiomyocyte diastolic properties.
{"title":"Quantification of Diastolic Viscoelastic Properties of Isolated Cardiac Muscle Cells","authors":"C. Baicu, M. Zile","doi":"10.1115/imece2001/bed-23158","DOIUrl":"https://doi.org/10.1115/imece2001/bed-23158","url":null,"abstract":"\u0000 Pathological processes which cause diastolic congestive heart failure (CHF), such as pressure overload hypertrophy (POH), produce abnormalities in the material properties of cardiac muscle cells (cardiomyocytes) and may selectively alter its elastic stiffness, viscosity, or both. Previous methods used to characterize these cardiomyocyte viscoelastic properties were constrained by specific biological and engineering limitations, which prevented testing in conditions that mimic normal physiology. The current study proposes an uniaxial variable-rate stretching method, in which isolated cardiomyocytes embedded in a three-dimensional gel matrix were subjected to stretch. Physiological Ca++ (2.5 mM) and rapid stretch rates up to 100 μm/sec provided experimental conditions parallel to in vivo physiology. The proposed method identified and individually quantified both cellular stiffness and viscosity, and showed that POH increased both elastic and viscous cardiomyocyte diastolic properties.","PeriodicalId":7238,"journal":{"name":"Advances in Bioengineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86772880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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