Analysis of Accumulator Effect on the Suppression of Fluid Pulsation

Background. Angiogenesis is a prerequisite step to achieve the success of bone regeneration by tissue engineering technology. Previous studies have shown the role of cerebrospinal fluid pulsation (CSFP) stress in the reconstruction of tissue-engineered laminae. In this study, we investigated the role of CSFP stress in the angiogenesis of tissue-engineered laminae. Methods. For the in vitro study, a CSFP bioreactor was used to investigate the impact of CSFP stress on the osteogenic mesenchymal stem cells (MSCs). For the in vivo study, forty-eight New Zealand rabbits were randomly divided into the CSFP group and the Non-CSFP group. Tissue-engineered laminae (TEL) was made by hydroxyapatite-collagen I scaffold and osteogenic MSCs and then implanted into the lamina defect in the two groups. The angiogenic and osteogenic abilities of newborn laminae were examined with histological staining, qRT-PCR, and radiological analysis. Results. The in vitro study showed that CSFP stress could promote the vascular endothelial growth factor A (VEGF-A) expression levels of osteogenic MSCs. In the animal study, the expression levels of angiogenic markers in the CSFP group were higher than those in the Non-CSFP group; moreover, in the CSFP group, their expression levels on the dura mater surface, which are closer to the CSFP stress stimulation, were also higher than those on the paraspinal muscle surface. The expression levels of osteogenic markers in the CSFP group were also higher than those in the Non-CSFP group. Conclusion. CSFP stress could promote the angiogenic ability of osteogenic MSCs and thus promote the angiogenesis of tissue-engineered laminae. The pretreatment of osteogenic MSC with a CSFP bioreactor may have important implications for vertebral lamina reconstruction with a tissue engineering technique.

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Cyclic pulsation stress promotes bone formation of tissue engineered laminae through the F-actin/YAP-1/β-Catenin signaling axis

npj Regenerative Medicine ◽

10.1038/s41536-021-00164-w ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Linli Li ◽

Hailong Li ◽

Yiqun He ◽

Han Tang ◽

Jian Dong ◽

...

Keyword(s):

Bone Formation ◽

Blood Vessel ◽

Stromal Cells ◽

Nuclear Translocation ◽

Therapeutic Approaches ◽

Blood Vessel Formation ◽

Vessel Formation ◽

Signaling Axis ◽

Fluid Pulsation ◽

Spinal Degeneration

AbstractMechanical loads are fundamental regulators of bone formation and remodeling. However, the molecular regulation of mechanotransduction during vertebral laminae regeneration remains poorly understood. Here, we found that cerebrospinal fluid pulsation (CSFP) stress—cyclic pulsation stress—could promote the osteogenic and angiogenic abilities of rat mesenchymal stromal cells (MSC), thereby promoting tissue-engineered laminae’s bone and blood vessel formation. In the process, F-actin relayed CSFP stress to promote the nuclear translocation of YAP1, which then decreased the degradation and promoted the nuclear translocation of β-Catenin. In turn, the nuclear translocation of β-Catenin promoted the osteogenic differentiation and angiogenic abilities of MSC, thereby promoting tissue-engineered laminae’s bone and blood vessel formation. Thus, we conclude that CSFP promotes the osteogenesis and angiogenesis of tissue-engineered laminae through the F-actin/YAP-1/β-Catenin signaling axis. This study advances our understanding of vertebral laminae regeneration and provides potential therapeutic approaches for spinal degeneration after spinal laminectomy.

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Longitudinal Heat Transfer in Oscillatory Flows in Pipes With Thermally Permeable Wall

Journal of Heat Transfer ◽

10.1115/1.2836306 ◽

1995 ◽

Vol 117 (4) ◽

pp. 884-888 ◽

Cited By ~ 2

Author(s):

T. Inaba

Keyword(s):

Heat Transfer ◽

Temperature Field ◽

Permeable Wall ◽

Time Varying ◽

Womersley Number ◽

Oscillatory Flows ◽

Quadratic Curve ◽

Mean Temperature ◽

Fluid Pulsation ◽

Lower Temperature

The effect of a thermally permeable wall on the enhanced longitudinal heat transfer by fluid pulsation in a pipe has been investigated. An analytical solution is obtained for the case when heat loss through the wall over a cycle of fluid pulsation is uniform along the pipe. The distribution of time-averaged sectional mean temperature is expressed by a quadratic curve. The rate of longitudinal heat transfer decreases linearly toward the lower temperature end. The amplitude of time-varying sectional mean temperature also decreases toward the same end. The effect of the value of Womersley number on this temperature field is discussed.

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Discriminating hadronic and quark stars through gravitational waves of fluid pulsation modes

Classical and Quantum Gravity ◽

10.1088/0264-9381/31/15/155002 ◽

2014 ◽

Vol 31 (15) ◽

pp. 155002 ◽

Cited By ~ 14

Author(s):

C Vásquez Flores ◽

G Lugones

Keyword(s):

Gravitational Waves ◽

Quark Stars ◽

Fluid Pulsation

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Characterization of a Pulsating Drill Bit Blaster

Volume 1A, Symposia: Turbomachinery Flow Simulation and Optimization; Applications in CFD; Bio-Inspired and Bio-Medical Fluid Mechanics; CFD Verification and Validation; Development and Applications of Immersed Boundary Methods; DNS, LES and Hybrid RANS/LES Methods; Fluid Machinery; Fluid-Structure Interaction and Flow-Induced Noise in Industrial Applications; Flow Applications in Aerospace; Active Fluid Dynamics and Flow Control — Theory, Experiments and Implementation ◽

10.1115/fedsm2016-7868 ◽

2016 ◽

Author(s):

Nicholas J. Thorp ◽

Geir Hareland ◽

Brian R. Elbing ◽

Runar Nygaard

Keyword(s):

Drilling Fluid ◽

Fluid Pressure ◽

Pressure Oscillation ◽

Drill String ◽

Operating Conditions ◽

Drill Bit ◽

Pulsation Frequency ◽

Design Changes ◽

Weight On Bit ◽

Fluid Pulsation

The drill bit blaster (DBB) studied in this paper aims to maximize the drilling rate of penetration (ROP) by using a flow interrupting mechanism to create drilling fluid pulsation. The fluctuating fluid pressure gradient generated during operation of the DBB could lead to more efficient bit cutting efficiency due to substrate depressurization and increased cutting removal efficiency and the vibrations created could reduce the drill string friction allowing a greater weight on bit (WOB) to be achieved. In order to maximize these mechanisms the effect of several different DBB design changes and operating conditions was studied in above ground testing. An analytical model was created to predict the influence of various aspects of the drill bit blaster design, operating conditions and fluid properties on the bit pressure characteristics and compared against experimental results. The results indicate that internal tool design has a significant effect on the pulsation frequency and amplitude, which can be accurately modeled as a function of flowrate and internal geometry. Using this model an optimization study was conducted to determine the sensitivity of the fluid pulsation power on various design and operating conditions. Application of this technology in future designs could allow the bit pressure oscillation frequency and amplitude to be optimized with regard to the lithology of the formations being drilled which could lead to faster, more efficient drilling potentially cutting drilling costs and leading to a larger number of oil and natural gas plays being profitable.

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Three - dimensional fluid attenuated inversion recovery sequence on 3 tesla magnetic resonace imaging in cranial nerve pathologies: Two case reports

Journal of Clinical Medicine- Hue Central Hospital ◽

10.38103/jcmhch.2021.72.1 ◽

2021 ◽

Author(s):

Thuyet Dinh Van

Keyword(s):

Cranial Nerve ◽

Case Reports ◽

Three Dimensional ◽

Inversion Recovery ◽

Inversion Recovery Sequence ◽

Recovery Sequence ◽

Flair Sequence ◽

Fluid Attenuated Inversion Recovery ◽

Fluid Pulsation ◽

3D Flair

Three - dimensional fluid attenuated inversion recovery sequence (3D-FLAIR) was introduced as a practical sequence which helps to reduce the cerebrospinal fluid pulsation and flow artefacts of conventional 2D acquisition and brings contiguous slices, ability in reformatting in variable planes which are typical features of 3D acquisition. 3D - FLAIR has been applied on assessing several neurologic pathologies. In this article, we introduce the application of 3D - FLAIR sequence without contrast enhancement on detecting abnormalities of cranial nerve pathology by presenting two cases, acute vestibular neuritis and facial nerve palsy. We suggest that 3D - FLAIR is the relatively useful sequence in detecting cranial nerve pathologies.

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