Investigation on Loading-Induced Fluid Flow in Osteogenesis Imperfecta Bone

Author(s):  
Nikhil V. Shrivas ◽  
Abhishek Kumar Tiwari ◽  
Rakesh Kumar ◽  
Dharmendra Tripathi ◽  
Vasu Raman Sharma

Osteogenesis Imperfecta (OI) is a genetic bone disorder which is typically characterized by brittle bones with frequent fractures. It is also known as brittle bone disease. Surgical procedure is one of the ways adopted by clinicians for the management of OI. In recent years, it has however become clear that physical activity is equally important for managing OI in both children and adults. Exogenous mechanical stimulation e.g. prophylactic exercises may be useful in improving the bone mass and strength of OI bones as loading-induced mechanical components e.g. normal strain and canalicular fluid flow stimulate remodeling activities. Several studies have characterized the strain environment in OI bones, whereas, very few studies attempted to characterize the canalicular fluid flow. In the present study, we anticipate that canalicular fluid flow reduces in OI bone as compared to healthy bone under physiological loading. This work accordingly computes the canalicular fluid distribution in the single osteon model of OI and control/normal bones subjected to normal physiological loadings. A transversely isotropic poroelastic model of osteon is developed. Loading is applied in accordance with gait cycles reported for OI and healthy bones. Fluid distribution patterns computed for OI and healthy bones are compared at different time-points of stance phase of the gait cycle. A significant reduction in fluid flow is observed in case of OI bone as compared to healthy bone. This clearly indicates that improvements in physical activities or exercises can be designed to enhance the level of canalicular fluid flow to initiate possible osteogenic activities and the bone.

Author(s):  
Nikhil Vivek Shrivas ◽  
Abhishek Kumar Tiwari ◽  
Rakesh Kumar ◽  
Santosh Patil ◽  
Dharmendra Tripathi ◽  
...  

Abstract Osteogenesis Imperfecta (OI), also known as 'brittle bone disease', is a genetic bone disorder. OI bones experience frequent fractures. It is observed physical activity is equally beneficial in reducing OI bone fractures in both children and adults as mechanical stimulation improves bone mass and strength. Loading-induced mechanical strain and interstitial fluid flow stimulates bone remodeling activities. Several studies have characterized strain environment in OI bones, whereas, a very few studies attempted to characterize the interstitial fluid flow. OI significantly affect bone microarchitecture. Thus, the present study anticipates that canalicular fluid flow reduces in OI bone in comparison to healthy bone in response to physiological loading due to altered poromechanical properties. Hence, this work attempts to understand the canalicular fluid distribution in the single osteon model of OI and healthy bones. A poromechanical model of osteon is developed to compute pore-pressure and interstitial fluid flow as a function of gait loading pattern reported for OI and healthy subjects. Fluid distribution patterns are compared at different time-points of stance phase of the gait cycle. It is observed that fluid flow significantly reduces in OI bone. Additionally, flow is more static than dynamic in OI osteon in comparison to healthy subjects. The present work attempts to identify the plausible explanation behind low mechano-transduction capability of OI bone. This work may further be extended in designing better biomechanical strategies to enhance fluid flow in order to improve osteogenic activities in OI bone.


Bone ◽  
2019 ◽  
Vol 127 ◽  
pp. 646-655 ◽  
Author(s):  
Yi Liu ◽  
Jianhai Wang ◽  
Shuo Liu ◽  
Mingjie Kuang ◽  
Yaqing Jing ◽  
...  

2020 ◽  
Vol 224 (3) ◽  
pp. 1670-1683
Author(s):  
Liming Zhao ◽  
Genyang Tang ◽  
Chao Sun ◽  
Jianguo Zhao ◽  
Shangxu Wang

SUMMARY We conducted stress–strain oscillation experiments on dry and partially oil-saturated Fontainebleau sandstone samples over the 1–2000 Hz band at different confining pressures to investigate the wave-induced fluid flow (WIFF) at mesoscopic and microscopic scales and their interaction. Three tested rock samples have similar porosity between 6 and 7 per cent and were partially saturated to different degrees with different oils. The measurement results exhibit a single or two attenuation peaks that are affected by the saturation degree, oil viscosity and confining pressure. One peak, exhibited by all samples, shifts to lower frequencies with increasing pressure, and is mainly attributed to grain contact- or microcrack-related squirt flow based on modelling of its characteristics and comparison with other experiment results for sandstones. The other peak is present at smaller frequencies and shifts to higher frequencies as the confining pressure increases, showing an opposite pressure dependence. This contrast is interpreted as the result of fluid flow patterns at different scales. We developed a dual-scale fluid flow model by incorporating the squirt flow effect into the patchy saturation model, which accounts for the interaction of WIFFs at microscopic and mesoscopic scales. This model provides a reasonable interpretation of the measurement results. Our broad-frequency-band measurements give physical evidence of WIFFs co-existing at two different scales, and combining with modelling results, it suggests that the WIFF mechanisms, related to pore microstructure and fluid distribution, interplay with each other and jointly control seismic attenuation and dispersion at reservoir conditions. These observations and modelling results are useful for quantitative seismic interpretation and reservoir characterization, specifically they have potential applications in time-lapse seismic analysis, fluid prediction and reservoir monitoring.


Geophysics ◽  
1997 ◽  
Vol 62 (1) ◽  
pp. 309-318 ◽  
Author(s):  
Jorge O. Parra

The transversely isotropic poroelastic wave equation can be formulated to include the Biot and the squirt‐flow mechanisms to yield a new analytical solution in terms of the elements of the squirt‐flow tensor. The new model gives estimates of the vertical and the horizontal permeabilities, as well as other measurable rock and fluid properties. In particular, the model estimates phase velocity and attenuation of waves traveling at different angles of incidence with respect to the principal axis of anisotropy. The attenuation and dispersion of the fast quasi P‐wave and the quasi SV‐wave are related to the vertical and the horizontal permeabilities. Modeling suggests that the attenuation of both the quasi P‐wave and quasi SV‐wave depend on the direction of permeability. For frequencies from 500 to 4500 Hz, the quasi P‐wave attenuation will be of maximum permeability. To test the theory, interwell seismic waveforms, well logs, and hydraulic conductivity measurements (recorded in the fluvial Gypsy sandstone reservoir, Oklahoma) provide the material and fluid property parameters. For example, the analysis of petrophysical data suggests that the vertical permeability (1 md) is affected by the presence of mudstone and siltstone bodies, which are barriers to vertical fluid movement, and the horizontal permeability (1640 md) is controlled by cross‐bedded and planar‐laminated sandstones. The theoretical dispersion curves based on measurable rock and fluid properties, and the phase velocity curve obtained from seismic signatures, give the ingredients to evaluate the model. Theoretical predictions show the influence of the permeability anisotropy on the dispersion of seismic waves. These dispersion values derived from interwell seismic signatures are consistent with the theoretical model and with the direction of propagation of the seismic waves that travel parallel to the maximum permeability. This analysis with the new analytical solution is the first step toward a quantitative evaluation of the preferential directions of fluid flow in reservoir formation containing hydrocarbons. The results of the present work may lead to the development of algorithms to extract the permeability anisotropy from attenuation and dispersion data (derived from sonic logs and crosswell seismics) to map the fluid flow distribution in a reservoir.


2016 ◽  
Vol 792 ◽  
pp. 5-35 ◽  
Author(s):  
Giuseppe A. Zampogna ◽  
Alessandro Bottaro

The interaction between a fluid flow and a transversely isotropic porous medium is described. A homogenized model is used to treat the flow field in the porous region, and different interface conditions, needed to match solutions at the boundary between the pure fluid and the porous regions, are evaluated. Two problems in different flow regimes (laminar and turbulent) are considered to validate the system, which includes inertia in the leading-order equations for the permeability tensor through a Oseen approximation. The components of the permeability, which characterize microscopically the porous medium and determine the flow field at the macroscopic scale, are reasonably well estimated by the theory, both in the laminar and the turbulent case. This is demonstrated by comparing the model’s results to both experimental measurements and direct numerical simulations of the Navier–Stokes equations which resolve the flow also through the pores of the medium.


1965 ◽  
Vol 5 (01) ◽  
pp. 15-24 ◽  
Author(s):  
Norman R. Morrow ◽  
Colin C. Harris

Abstract The experimental points which describe capillary pressure curves are determined at apparent equilibria which are observed after hydrodynamic flow has ceased. For most systems, the time required to obtain equalization of pressure throughout the discontinuous part of a phase is prohibitive. To permit experimental points to be described as equilibria, a model of capillary behavior is proposed where mass transfer is restricted to bulk fluid flow. Model capillary pressure curves follow if the path described by such points is independent of the rate at which the saturation was changed to attain a capillary pressure point. A modified suction potential technique is used to study cyclic relationships between capillary pressure and moisture content for a porous mass. The time taken to complete an experiment was greatly reduced by using small samples. Introduction Capillary retention of liquid by porous materials has been investigated in the fields of hydrology, soil science, oil reservoir engineering, chemical engineering, soil mechanics, textiles, paper making and building materials. In studies of the immiscible displacement of one fluid by another within a porous bed, drainage columns and suction potential techniques have been used to obtain relationships between pressure deficiency and saturation (Fig. 1). Except where there is no hysteresis of contact angle and the solid is of simple geometry, such as a tube of uniform cross section, there is hysteresis in the relationship between capillary pressure and saturation. The relationship which has received most attention is displacement of fluid from an initially saturated bed (Fig. 1, Curve Ro), the final condition being an irreducible minimum fluid saturation Swr. Imbibition (Fig. 1, Curve A), further desaturation (Fig. 1, Curve R), and intermediate scanning curves have been studied to a lesser but increasing extent. This paper first considers the nature of the experimental points tracing the capillary pressure curves with respect to the modes and rates of mass transfer which are operative during the course of measurement. There are clear indications that the experimental points which describe these curves are obtained at apparent equilibria which are observed when viscous fluid flow has ceased; and any further changes in the fluid distribution are the result of much slower mass transfer processes, such as diffusion. Unless stated otherwise, this discussion applies to a stable packing of equal, smooth, hydrophilic spheres supported by a suction plate with water as the wetting phase and air as the nonwetting phase. SPEJ P. 15ˆ


Endocrinology ◽  
2002 ◽  
Vol 143 (5) ◽  
pp. 1594-1601 ◽  
Author(s):  
I. Kalajzic ◽  
J. Terzic ◽  
Z. Rumboldt ◽  
K. Mack ◽  
A. Naprta ◽  
...  

Abstract This work examines the cellular pathophysiology associated with the weakened bone matrix found in a murine model of osteogenesis imperfecta murine (oim). Histomorphometric analysis of oim/oim bone showed significantly diminished bone mass, and the osteoblast and osteoclast histomorphometric parameters were increased in the oim/oim mice, compared with wild-type (+/+) mice. To assess osteoblast activity, a rat Col1a1 promoter linked to the chloramphenicol acetyltransferase reporter transgene was bred into the oim model. At 8 d and 1 month of age, no difference in transgene activity between oim and control mice was observed. However, at 3 months of age, chloramphenicol acetyl transferase activity was elevated in oim/oim;Tg/Tg, compared with +/+;Tg/Tg and oim/+;Tg/Tg. High levels of urinary pyridinoline crosslinks in the oim/oim;Tg/Tg mice were present at all ages, reflecting continuing high bone resorption. Our data portray a state of ineffective osteogenesis in which the mutant mouse never accumulates a normal quantity of bone matrix. However, it is only after the completion of the rapid growth phase that the high activity of the oim/oim osteoblast can compensate for the high rate of bone resorption. This relationship between bone formation and resorption may explain why the severity of osteogenesis imperfecta decreases after puberty is completed. The ability to quantify high bone turnover and advantages of using a transgene that reflects osteoblast lineage activity make this a useful model for studying interventions designed to improve the bone strength in osteogenesis imperfecta.


2001 ◽  
Vol 2001 (2) ◽  
pp. 1381-1389 ◽  
Author(s):  
Theodore E. Camlin

ABSTRACT On December 20, 1999 at approximately 1045 hours, crude oil was discovered in the Leaf River near Collins, Mississippi. The investigation determined the discharge was approximately 8,000 barrels originating from a source in the vicinity of State Highway 28 and Summerland Road, Jones County, Mississippi. The point of the release was located inland and in an upland type environment approximately 8 miles from the discovery location (Highway 84 bridge) near Collins, Mississippi. After the line was shut-in and control of the source was certain, it was determined there were three distinct types of work areas remaining for the cleanup operations: an upland marsh type environment, an ephemeral flow creek bed, and a limited access river environment. Strategic objectives for the response included prevention of any further migration of oil down the Leaf River; and prevent any additional oil from migrating or being flushed (during the next rain event) out of the upland marsh area down the unnamed creek and entering the Leaf River. The focus of this paper is on the measures pursued by operations and the Unified Command that were designed to prevent any further oiling of the Leaf River in the event oil was flushed out of the upper marshy area as a result of the cleanup operations or from a rain event. Operations installed a series of underflow dams at the confluence of the unnamed creek and the Leaf River as well as between the unnamed creek and the upland marsh area. These two stopgaps provided the necessary containment for the anticipated rain events forecast to occur early in the new year. The series of dams were successful in controlling the total fluid flow, containing flushed oil, and preventing additional oiling of the Leaf River during the first rain and throughout the remainder of the response.


Sign in / Sign up

Export Citation Format

Share Document