bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing of a Novel Hip Prosthesis Design
Authors: Riley Shawn P. , Santare Michael H. , Advani Suresh G. , Miller Freeman 
Published: November 2021

Abstract
Total hip arthroplasty (THA) has been in use with reasonable and increasing success for over 40 years. However, the conventional, long-stemmed, Charnley (1960) implant alters the natural loading in the proximal femur from bending and axial load to more of a shear and circumferential load. This change in load often causes the bone to remodel, which can eventually lead to loosening of the implant. This problem is particularly common among younger, more active THA recipients. Therefore, patients under age 60, who could benefit from THA may be encouraged to postpone surgery to reduce the potential need for future revision surgeries caused by loosened prostheses. The authors’ overall goal in this work was to design and test a new prosthesis that reduces this stress redistribution using a rigorous engineering approach.
Surface Topography and Cartilage Thickness Templates for the Femur and Patella Based on an Average of Healthy Articular Surfaces
Authors: Cohen Zohara A. , Levine William N. , Mow Van C. , Ateshian Gerard A. 
Published: November 2021

Abstract
The patella and femur surfaces of 14 healthy human knee joints were used to create average articular surface topographies and average cartilage thickness maps. The maps are shown to be useful as templates for the identification of lesions on patient-specific thickness maps.
Dynamic and Swelling Behaviors of Porcine Annulus Fibrosus in Compression
Authors: DiDonato D. G. , Justiz M. A. , Gu W. Y. 
Published: November 2021

Abstract
Low back pain is a major socio-economic concern in this country [1, 2]. More than seventy percent of all people have back pain at some point in life, with the annual prevalence of back pain ranging from 15–45%. Although the exact cause follow back pain is unclear, the degenerative changes of the intervertebral disc (IVD), a crucial component of the human spine, have been implicated as a possible primary etiologic factor [1, 3–4]. Since the IVD functions in vivo to provide load support and spine flexibility [1, 2], the relationship between its biomechanical behavior and tissue composition and structure needs to be defined and measured.
A Novel Method for Measuring the Optical Activity of Biopolymers and Application in Measuring Denaturation of Type I Collagen
Authors: Majewski Alexander J. , Sanzari Martin 
Published: November 2021

Abstract
Optical Activity is defined as a property, in which a substance will absorb incident (optical) radiation and / or change its polarization state. Molecules of this type are known as chiral (its mirror image cannot be superimposed upon itself i.e. the molecule has a handedness). Optical Rotatory Dispersion (circular birefringence) occurs when a material exhibits a difference in its index for right-handed (nR) or left-handed (nL) circularly polarized light. In terms of the indices of refraction, the observed rotation is defined as: α = (πd/λo) (nL − nR). Where: nL = index of refraction for left-handed polarization; nR = index of refraction for right-handed polarization; d = path length (sample thickness); λo = wavelength of incident radiation measured in vacuum. We have developed and tested a new instrument that measures the optical rotatory properties of biopolymers. The advantage of this instrument is that it allows a real time measurement of the optical activity of biopolymers; which can be used to monitor samples for changes of state. By using a differential measurement scheme, system errors are minimized and resolution is increased over current measurement techniques. A study of the denaturation process of type I collagen will be presented.
A Clinical Evaluation of Vibration Testing in the Assessment of Osteoporosis
Authors: Kasra Mehran , Grynpas Marc D. , Soric Rajka , Arnaud Sara 
Published: November 2021

Abstract
Bone fracture is one of the most common medical problems which reduces the quality of life of individuals. In the United States, osteoporosis alone causes 1.3 million bone fractures a year, with an annual cost of $5.2 billion dollars. Osteoporosis is a disease in which low bone mass and changes in bone quality and architecture increase the risk of fractures. Women are at greater risk of developing osteoporosis than men. Osteoporosis targets both trabecular and cortical bone (Kanis et al., 1994; Kasra and Grynpas, 1994). Therefore, bone density of cortical bone structures such as ulna and mid-radius may be used as a predictor of osteoporotic fractures (Cummings et al., 1993). Bone quality assessment and predicting the risk of bone fracture is very important in prevention of fracture and proper bone treatment. In the NIH Consensus Development Statement (1984), the need for improved measurement techniques is emphasized.
Role of Trabecular Bone Distribution in Femoral Neck Biomechanics
Authors: Fox Julia C. , Keaveny Tony M. 
Published: November 2021

Abstract
Body weight, habitual postures and activities are the primary determinants of the nature and magnitude of loads acting on the proximal femur, the distribution of which influences the development of the bone structure and geometry (Wolff, 1892). This phenomena, called functional adaptation, has long been an area of interest in the field of bone mechanics, particularly with reference to compensatory geometric remodeling of long bones with decreasing bone mass (Martin et al. 1977; Ruff et al. 1988; Kannus et al., 1996). However, the extent to which compensatory remodeling occurs in the femoral neck remains unclear (Horikoshi, 1999; Beck, 1993). A potential adaptation of the femoral neck may be characterized by the asymmetric distribution of trabecular and cortical bone in the femoral neck cross-section, i.e. there is a disparity in superior and inferior cortical thickness (Bell, 1999; Boyce, 1993), referred to here as an eccentricity.
Biomechanics of Lumbar Spondylotic Degeneration
Authors: Cusick Joseph F. , Kumaresan Srirangam , Bunch Brian , Yoganandan Narayan , Pintar Frank A. 
Published: November 2021

Abstract
Human lumbar spinal columns exhibit different degrees of spondylotic degeneration. However, the biomechanical effects of these changes have not been fully studied. Understanding the potential patterns of such responses relative to the severity of degenerative changes assist in clarifying the influence on clinical and laboratory investigations. This study was conducted to obtain the three-dimensional biomechanical stability parameters of degenerated and non-degenerated spines. The degree of degeneration in disc and facet joints was graded individually for severity allowing evaluation of overall effects as well as individual component influences. Pure moment and complex loading were applied under flexion, extension, and left and right lateral bending modalities. The degenerated columns responded with greater variations in the moment-rotation (pure-moment loading) and force-deflection and moment-rotation (combined loading) than normal spinal columns. Furthermore, the response of the degenerated column depended not only on the overall quality of the spine, but also on the difference in severity and type of components affected. Complex loading showed increased sensitivity to variations in the biomechanical responses compared to pure moment loading. Disc degeneration showed increased changes in rotational stability, whereas facet alterations demonstrated greater effects on axial stiffness.
Biomechanics of Carotid Artery Dissection in Vehicular Accidents
Authors: Sances Anthony , Carlin Fred H. , Daniels David , Cusick Joseph F. 
Published: November 2021

Abstract
Carotid and vertebral artery dissections are often associated with hyperextension of the neck or rapid hyperrotation of the head. In each of these cases, the arteries are damaged by being stretched over the upper cervical vertebra. A dissecting aneurysm ensues in which blood makes its way between the layers of the vessel wall eventually resulting in a thrombosis and cerebral infarct. Typical mechanisms of these injuries in the automotive environment are the absence of a head restraint, shoulder harness trauma, and whiplash. These mechanisms together with blunt trauma and inertial forces are discussed.
LDA Study of the Flow Associated With the Design Differences and Orientations of the Bileaflet Mechanical Prostheses
Authors: Akutsu Toshinosuke , Higucchi Daiki , Taguchi Tomohiro 
Published: November 2021

Abstract
Four typical mechanical bileaflet heart valves (St. Jude Medical, Advancing The Standard, Carbomedics, and Jyros valves) have been tested in the mitral position under pulsatile flow conditions. Measurements of velocity and turbulent stresses were conducted at five downstream locations using a sophisticated cardiac simulator in conjunction with a highly sensitive two-component LDA. Comparison of these flow fields associated with the opening and subsequent accelerating phase of the flow revealed similarity and dissimilarity of the flow field associated with the different valve designs and helped established visualizing the effect of the valve designs and orientations on the flow.
Distribution of Oxygen Tension in Neocortical Areas in the Rat Somatosensory Cortex
Authors: Masamoto Kazuto , Oka Kotaro , Kobayashi Hirosuke , Sannohe Yuki , Takizawa Naosada , Tanishita Kazuo 
Published: November 2021

Abstract
The purpose of this study is to identify the localized differentiation of oxygen transport in the brain. We measured oxygen tension in three neocortical areas (FL, HL, and Tr) of the rat somatosensory cortex by microcoaxial needle electrodes. The structure of neocortical area is characterized by the variation of cell shape, spatial distribution and size, which results in the following three types of the oxygen tension distribution; random, fluctuation, and hypoxia.
Use of Natural Hydroxyapatite for Coating of Titanium for Implantation
Authors: Pal Subrata , Shinde Santosh N. , Roy Sukumar 
Published: November 2021

Abstract
It is welknown that titanium is the best biocompatiable metal available till date. Since commercially pure titanium (cpTi) has satisfactory mechanical properties, including sufficient ductility, together with a thermal expansion coefficient similar to that of hydroxyapatite, corrosion resistance and blood and tissue compatible behavior, it was selected for coating with hydroxyapatite.
Advanced Stochastic Techniques for Jet Engine Component Life Prediction
Authors: Ghiocel Dan M. 
Published: November 2021

Abstract
The paper addresses significant aspects of stochastic modeling for jet engine component life prediction. Probabilistic life prediction for gas turbine engine components represents a very difficult engineering problem involving stochastic modeling of multiple, complex random phenomena. A key aspect for developing a probabilistic life prediction tool is to incorporate, and to be open to modeling advances related to dynamic complex random phenomena, including space-time random variabilities of mission environment and material parameters, aero-elastic interactions, friction at contact interfaces, multi-site fatigue, progressive damage mechanism, including loading interactions, etc.. The paper addresses the main aspects involved in stochastic modeling of component fatigue life prediction for jet engine rotating components, specifically fan blades. The paper highlights the need of the use of stochastic process and field models for including space-time varying random aspects.
Mission speed profiles produced by pilot’s random maneuvers are modeled by pulse non-Gaussian stochastic processes. These pulse processes are approximated using linear recursive models when the cluster effects are not significant. A more general approach, useful when cluster effects are significant, based on a combination of two pulse processes is used. Aero-pressure distribution on blade as well as blade surface geometry deviations due to manufacturing are idealized by using factorable stochastic field models. Also, stochastic field models are used for modeling strain-life and damage accumulation curves. Stochastic damage accumulation models are based on randomized stress-dependent models (nonlinear damage rule models).
The paper also addresses mathematical modeling of stochastic nonlinear responses in multidimensional parameter spaces. Stochastic response surface techniques based on factorable stochastic fields or optimum stochastic models are suggested.
An illustrative example of a jet engine blade is used for discussion and to show the consequences of different modeling assumptions.
Microstructural Characterization of Micro-Textured Titanium Surfaces
Authors: Soboyejo W. O. , Mercer C. , Allameh S. , Nemetski B. , Marcantonio N. , Ricci J. 
Published: November 2021

Abstract
This paper presents the results of a multi-scale microstructural characterization of micro-textured Ti-6Al-4V surfaces that are used in biomedical implants. The hierarchies of substructural and microstructural features associated with laser micro-texturing, polishing and surface blasting with alumina pellets are elucidated via atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy (OM). The nano-scale roughness profiles associated with the different surface textures are elucidated via AFM. Sub-micron precipitates and dislocation substructures associated with wrought processing and laser processing are revealed by TEM. Micro- and meso-scale images of the groove structures are then discussed using OM and SEM. The implications of the results are discussed for the optimization of laser processing schemes for the fabrication of micro-textured surfaces that will facilitate the self organization of proteins, and the attachment of mammalian cells to the Ti-6Al-4V surfaces in biomedical implants.
Mechanisms for Interfacial Toughness Loss in Thermal Barrier Coating Systems
Authors: Handoko R. A. , Beuth J. L. , Stiger M. J. , Pettit F. S. , Meier G. H. 
Published: November 2021

Abstract
A major concern with thermal barrier coatings (TBCs) is their loss of adhesion during service, leading to spallation. In this research, an indentation test is used to quantify decreases in interfacial toughness of TBC systems as a function of the duration of isothermal or cyclic high-temperature exposures. A detailed description is given of the indentation test, which involves penetration of the TBC and the oxide layer below it, inducing plastic deformation in the underlying metal bond coat and superalloy substrate. This plastic deformation induces a compressive radial stress away from the indent, which drives an axisymmetric delamination of the TBC and oxide layers. Detailed elastic-plastic model results are presented which allow determination of the toughness of the oxide/bond coat interface from a measured radius of delamination.
Thermal Spray Processing of Nanostructured Materials
Authors: Lavernia Enrique J. 
Published: November 2021

Abstract
The application of nanocrystalline materials used as powder feedstock for thermal spraying in recent years has been mainly facilitated by the wide range of powder sources available, including: vapor condensation, solution precipitation, combustion synthesis, sol-gel processing, thermochemical synthesis, and mechanical alloying/milling. The resultant thermal sprayed coatings have been shown to exhibit unique and often enhanced physical and mechanical performance properties in comparison to the coatings produced by current technology. Improvements in physical have been documented for several metallic and cermet based nanostructured coatings. However, the behavior of a nanostructured material during thermal spraying is rendered complex by factors such as morphology of feedstock powders; thermal stability of nanostructured powders; and thermal and momentum behavior of nanostructured powder. Optimization of chemistry, morphology and coating thickness, for example, should lead to the attainment of physical performance heretofore unattainable with conventional coatings. The present paper is to provide an overview of recent advancements in the field of high performance nanostructured coatings, paying particular attention to underlying fundamental issues. Examples of several metallic and cermet coatings will be used to demonstrate the influence of the morphology of nanostructured powders on the performance of the sprayed coatings.
A New Statistical Biomechanics Modeling of Physical and Biochemical Bone Strength Parameters
Authors: Soboyejo Alfred B. O. , Nestor Karl E. 
Published: November 2021

Abstract
New multiparameter biomechanics models are developed in this work for the characterization of bone strengths in broiler chickens and turkeys, as functions of the major physical and biochemical parameters, which can contribute to mechanical properties of bone strengths in these birds, under good management practices. Theoretical and experimental methods have been developed in this study to model bone strength as functions of (a) the physical parameters only and (b) the biochemical parameters only, which can affect bone strength. The choice of any particular methodology will depend on the availability of either the physical or biochemical parameters, which can be obtained from experimental data. Possible useful practical applications of the statistical biomechanics principles developed in this technical paper, particularly in the field of bone strength enhancement in turkeys and broiler chickens will be discussed.
In view of the problems described, the major objectives of the present study are as follows:
(1) To develop new multiparameter biomechanics models for the characterization of bone strengths in turkeys and broiler chickens as functions of the major physical only, or biomechanical parameters only, which can contribute to bone strength in these birds, under conditions of good management of these birds. This study will consider only the compressive buckling as the mode of structural failure in the cellular material of the bone.
(2) To highlight briefly the possible practical applications of the statistical biomechanics principles, which will be developed in this study to the genetic improvement of bone strengths in broiler chickens and turkeys.
Viscoelastic Effects on the Stability of Thin-Film Parallel Flow in Lubrication Applications
Authors: Harnoy Avraham , Shridhar Laksh. , Tavantzis John 
Published: November 2021

Abstract
The analysis is concerned with the effect of fluid-elasticity on the stability of laminar parallel flow. The widely used multi-grade oils contain polymer additives that make them viscoelastic. These oils are widely used for high shear-rate laminar flow of hydrodynamic lubrication, where flow instability is undesirable because it significantly increases the viscous friction losses. A fluid model is applied where the stress-relaxation effect is considered in addition to the fluid viscosity. However, the normal stresses are disregarded.
Extended Orr-Sommerfeld type analysis has been performed for elastic fluid films of lubrication. The conclusion is that the elasticity of the fluid has a destabilizing effect. For parallel flow, the transition to instability is at lower Reynolds number in comparison to Newtonian fluids.
Global-scale emergence of continental crust during the Mesoarchean–early Neoarchean
Authors: Wang Wei , Cawood Peter A. , Spencer Christopher J. , Pandit Manoj K. , Zhao Jun-Hong , Xia Xiao-Ping , Zheng Jian-Ping , Lu Gui-Mei 
Published: November 2021

Abstract
The timing of the emergence of subaerial landmasses is equivocally constrained as post-Archean and continues to be a much-debated issue. In this study, we document exceptionally 18O-depleted (δ18O &lt; 4.7‰) Mesoarchean to early Neoarchean magmatism in India that shows a similarity with the coeval low-δ18O magmas reported from Australia, South America, and northern China. Such global-scale low-δ18O magmatism would require high-temperature meteoric water–rock interaction in the uppermost crust synchronous with magma generation, necessitating the emergence of a substantial volume of the continental crust. The timing of this low-δ18O magmatism coincides with the development of extensive, subaerial large igneous provinces, a downward shift in δ18O and Δ17O values in pelitic rocks, the rise of normalized 87Sr/86Sr in seawater, and an intermittent upsurge in the proportion of atmospheric oxygen. We propose that the emergence of substantial volumes of continental crust initiated at ca. 3.2 Ga and peaked at 2.8–2.6 Ga, facilitating the generation of globally distributed low-δ18O magmas, and this event can be linked to the first appearance of atmospheric oxygen.
Adverse metabolic outcomes in the early and late postpartum after gestational diabetes are broader than glucose control
Authors: Kosinski Christophe , Rossel Jean-Benoît , Gross Justine , Helbling Céline , Quansah Dan Yedu , Collet Tinh-Hai , Puder Jardena J 
Published: November 2021

IntroductionGestational diabetes mellitus is associated with an increased cardiovascular risk. To better target preventive measures, we performed an in-depth characterization of cardiometabolic risk factors in a cohort of women with gestational diabetes in the early (6–8 weeks) and late (1 year) postpartum.Research design and methodsProspective cohort of 622 women followed in a university gestational diabetes clinic between 2011 and 2017. 162 patients who attended the late postpartum visit were analyzed in a nested long-term cohort starting in 2015. Metabolic syndrome (MetS) was based on the International Diabetes Federation definition, and then having at least two additional criteria of the MetS (blood pressure, triglycerides, high-density lipoprotein (HDL) cholesterol, plasma glucose above or below the International Diabetes Federation cut-offs).ResultsCompared with prepregnancy, weight retention was 4.8±6.0 kg in the early postpartum, and the prevalence of obesity, pre-diabetes, MetS-body mass index (BMI) and MetS-waist circumference (WC) were 28.8%, 28.9%, 10.3% and 23.8%, respectively. Compared with the early postpartum, weight did not change and waist circumference decreased by 2.6±0.6 cm in the late postpartum. However, the prevalence of obesity, pre-diabetes, MetS-WC and MetS-BMI increased (relative increase: 11% for obesity, 82% for pre-diabetes, 50% for MetS-WC, 100% for MetS-BMI; all p≤0.001).Predictors for obesity were the use of glucose-lowering treatment during pregnancy and the prepregnancy BMI. Predictors for pre-diabetes were the early postpartum fasting glucose value and family history of diabetes. Finally, systolic blood pressure in pregnancy and in the early postpartum, the 2-hour post oral glucose tolerance test glycemia and the HDL-cholesterol predicted the development of MetS (all p<0.05).ConclusionsThe prevalence of metabolic complications increased in the late postpartum, mainly due to an increase in fasting glucose and obesity, although weight did not change. We identified predictors of late postpartum obesity, pre-diabetes and MetS that could lead to high-risk identification and targeted preventions.