11,483 results match your criteria shear rate

Time-Aligned Plane Wave Compounding Methods for High-Frame-Rate Shear Wave Elastography: Experimental Validation and Performance Assessment on Tissue Phantoms.

Ultrasound Med Biol 2021 Apr 13. Epub 2021 Apr 13.

Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA; Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.

Shear wave elastography (SWE) is an ultrasonic technique able to quantitatively assess the mechanical properties of tissues by combining acoustic radiation force and ultrafast imaging. While utilizing coherent plane wave compounding enhances echo and shear wave motion signal-to-noise ratio (SNR), it also reduces the effective pulse repetition frequency (PRF), affecting the accuracy of the measurements of motion and, consequently, of material properties. It is important to maintain both high-motion SNR and PRF, particularly for the characterization of (material and/or geometrical) dispersive tissues such as arteries. Read More

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Oscillatory pressure-driven rarefied binary gas mixture flow between parallel plates.

Phys Rev E 2021 Mar;103(3-1):033103

Department of Mechanical Engineering, University of Thessaly, 38334 Volos, Greece.

The rarefied, oscillatory, pressure-driven binary gas mixture flow between parallel plates is computationally investigated in terms of the mixture molar fraction and molecular mass ratio of the species, in a wide range of gas rarefaction and oscillation frequency. Modeling is based on the McCormack kinetic model. The output quantities are in dimensionless form and include the flow rate, wall shear stress and pumping power of the mixture, as well as the velocity and shear stress distributions and flow rates of the species. Read More

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Computational method for bearing surface wear prediction in total hip replacements.

J Mech Behav Biomed Mater 2021 Apr 8;119:104507. Epub 2021 Apr 8.

School of Engineering, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.

Total hip replacement (THR) is a revolutionary treatment when a hip joint becomes severely damaged. Wear is known as one of the main reasons for THR failure. Current experimental techniques to investigate the wear at the bearing surfaces of THRs are time-consuming, complicated and expensive. Read More

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Elastoplastic Approach Based on Microscopic Insights for the Steady State and Transient Dynamics of Sheared Disordered Solids.

Phys Rev Lett 2021 Apr;126(13):138005

Univ. Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France.

We develop a framework to study the mechanical response of athermal amorphous solids via a coupling of mesoscale and microscopic models. Using measurements of coarse-grained quantities from simulations of dense disordered particulate systems, we present a coherent elastoplastic model approach for deformation and flow of yield stress materials. For a given set of parameters, this model allows us to match consistently transient and steady state features of driven disordered systems with diverse preparation histories under both applied shear-rate and creep protocols. Read More

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Formulation, Characterization, and Mineral Absorption of Fruit Extract Nanoemulsion.

J Am Coll Nutr 2021 Apr 15:1-10. Epub 2021 Apr 15.

Lovely Professional University, Phagwara, Punjab, India.

Objective: Loss of vital bioactive components of fruit extract during food processing is a major issue. Therefore, to retain the antioxidant potential and to increase the mineral bioavailability, gum arabic stabilized nanoemulsion of Fig fruit extract was prepared.

Method: . Read More

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Systematic Evaluation of Clinical Efficacy and Platelet Function of Sofren Injection in the Treatment of Angina Pectoris.

Evid Based Complement Alternat Med 2021 26;2021:5591137. Epub 2021 Mar 26.

The First Affiliated Hospital of Henan University of Chinese Medicine, Zhengzhou, Henan 450000, China.

To systematically evaluate the efficacy and safety of sofren injection combined with conventional Western medicine in the treatment of angina pectoris. Randomized controlled trials (RCTs) on the treatment of angina pectoris with sofren injection combined with Western medicine were collected by searching PubMed, the Cochrane Library, Embase, Web of Science, CNKI, Wanfang Database, Weipu Database, and China Biomedical Literature Service System (CBM) by computer with the retrieval time from establishment of database to August 2020. After literature screening according to the predetermined inclusion and exclusion criteria, data of eligible studies were extracted, and then, a meta-analysis was conducted with the RevMan 5. Read More

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Role of low molecular weight polymers on the dynamics of silicon anodes during casting.

Chemphyschem 2021 Apr 13. Epub 2021 Apr 13.

Oak Ridge National Laboratory, Chemical Sciences Division, UNITED STATES.

This work probes the slurry architecture of a high silicon content electrode slurry with and without low molecular weight polymeric dispersants as a function of shear rate to mimic electrode casting conditions for poly(acrylic acid) (PAA) and lithium neutralized poly(acrylic acid) (LiPAA) based electrodes. Rheology coupled ultra-small angle neutron scattering (rheo-USANS) was used to examine the aggregation and agglomeration behavior of each slurry as well as the overall shape of the aggregates. The addition of dispersant has opposing effects on slurries made with PAA or LiPAA binder. Read More

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Influence of shear rate and surface chemistry on thrombus formation in micro-crevice.

J Biomech 2021 Mar 26;121:110397. Epub 2021 Mar 26.

Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA. Electronic address:

Thromboembolic complications remain a central issue in management of patients on mechanical circulatory support. Despite the best practices employed in design and manufacturing of modern ventricular assist devices, complexity and modular nature of these systems often introduces internal steps and crevices in the flow path which can serve as nidus for thrombus formation. Thrombotic potential is influenced by multiple factors including the characteristics of the flow and surface chemistry of the biomaterial. Read More

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Depth and strain rate-dependent mechanical response of chondrocytes in reserve zone cartilage subjected to compressive loading.

Biomech Model Mechanobiol 2021 Apr 12. Epub 2021 Apr 12.

Department of Biomedical Engineering, University of Memphis, 330 Engineering Technology Building, Memphis, TN, 38152, USA.

The role of the growth plate reserve zone is not well understood. It has been proposed to serve as a source of stem cells and to produce morphogens that control the alignment of clones in preparation for the transition into the proliferative zone. We hypothesized that if such a role exists, there are likely to be mechanoregulatory stimuli in cellular response through the depth of the reserve zone. Read More

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Phase behavior and rheological properties of basil seed gum/whey protein isolate mixed dispersions and gels.

Food Sci Nutr 2021 Apr 18;9(4):1881-1895. Epub 2021 Feb 18.

Department of Food Science and Technology Sari Agricultural Sciences and Natural Resources University Sari Iran.

Many food formulations comprise proteins and polysaccharides simultaneously, contributing in the functional properties in food systems. In this study, the effects of basil seed gum (BSG) addition to whey protein isolate (WPI) dispersions were investigated through phase behavior, steady shear flow, and small amplitude oscillatory shear tests (SAOS). The phase behavior of WPI-BSG mixed solutions was dependent on the initial concentration of biopolymers, while the effect of BSG was predominant. Read More

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Oil Thickening with Organoclay Enhances the Ultraviolet Absorption Ability of Sunscreen on a Skin-mimicking Substrate.

J Oleo Sci 2021 Apr 12. Epub 2021 Apr 12.

School of Bioscience and Biotechnology, Tokyo University of Technology.

The performance of sunscreen products depends on their ultraviolet (UV) absorption ability through the film formed on the skin surface upon their application. Therefore, it is important that a uniform film is formed on the uneven skin surface for effective sunscreen performance. Because most UV filters are oil soluble, we hypothesized in this study that increasing the viscosity of the oil phase of a sunscreen product can improve the performance of the sunscreen. Read More

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Inclined and multi-directional surface impacts accelerate biodegradation and improve mechanical properties of pure iron.

J Mech Behav Biomed Mater 2021 Apr 2;119:104476. Epub 2021 Apr 2.

Department of Mechanical Engineering, Politecnico di Milano, Milan, Italy.

Impact based surface treatments with adequate kinetic energy have favorable effects on promoting cell-substrate interactions, reducing bacterial adhesion, and enhancing fatigue performance of metallic biomaterials. Here, we used both numerical and experimental approaches to evaluate the potential of these treatments for addressing the major issue associated with the application of pure iron in biomedical implants, i.e. Read More

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Assessment of the conjunctival microcirculation in adult patients with cyanotic congenital heart disease compared to healthy controls.

Microvasc Res 2021 Apr 7;136:104167. Epub 2021 Apr 7.

Department of Cardiology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, United Kingdom.

Purpose: Congenital heart disease (CHD) is the most common live birth defect and a proportion of these patients have chronic hypoxia. Chronic hypoxia leads to secondary erythrocytosis resulting in microvascular dysfunction and increased thrombosis risk. The conjunctival microcirculation is easily accessible for imaging and quantitative assessment. Read More

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Shear-driven Rolling of DNA-adhesive Microspheres.

Biophys J 2021 Apr 7. Epub 2021 Apr 7.

Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104. Electronic address:

Many biologically important cell binding processes, such as the rolling of leukocytes in the vasculature, are multivalent, being mediated by large numbers of weak binding ligands. Quantitative agreement between experiments and models of rolling has been elusive, and often limited by the poor understanding of the binding and unbinding kinetics of the ligands involved. Here we present a cell-free experimental model for such rolling, consisting of polymer microspheres whose adhesion to a glass surface is mediated by ligands with well-understood force-dependent binding free energy-short complementary DNA strands. Read More

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Signature of Transition between Granular Solid and Fluid: Rate-Dependent Stick Slips in Steady Shearing.

Phys Rev Lett 2021 Mar;126(12):128001

Institute of Physics, Academia Sinica, 11529 Taipei, Taiwan.

Despite extensive studies on either smooth granular-fluid flow or the solidlike deformation at the slow limit, the change between these two extremes remains largely unexplored. By systematically investigating the fluctuations of tightly packed grains under steady shearing, we identify a transition zone with prominent stick-slip avalanches. We establish a state diagram, and propose a new dimensionless shear rate based on the speed dependence of interparticle friction and particle size. Read More

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Tailoring the biological response of zirconium implants using zirconia bioceramic coatings: A systematic review.

J Trace Elem Med Biol 2021 Apr 2;66:126756. Epub 2021 Apr 2.

Department of Materials Engineering, Bu-Ali Sina University, Hamedan, 65178-38695, Iran. Electronic address:

Background: The poor biological performance of zirconium implants in the human body resulting from their bio-inertness and vulnerability to corrosion and bacterial activity reflects the need for further studies on substitution or performing the surface modification. The suggestion of employing zirconia (ZrO) bioceramic coatings for surface modification seems beneficial.

Objectives: This systematic review aims to identify and summarize existing documents reporting the biological responses for ZrO coatings produced by the PEO process on zirconium implants. Read More

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Assessment of the conjunctival microcirculation for patients presenting with acute myocardial infarction compared to healthy controls.

Sci Rep 2021 Apr 7;11(1):7660. Epub 2021 Apr 7.

Department of Cardiology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, UK.

Microcirculatory dysfunction occurs early in cardiovascular disease (CVD) development. Acute myocardial infarction (MI) is a late consequence of CVD. The conjunctival microcirculation is readily-accessible for quantitative assessment and has not previously been studied in MI patients. Read More

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Statistical techniques for predicting rupture risk in abdominal aortic aneurysms: A contribution based on bootstrap.

Sci Prog 2021 Apr-Jun;104(2):368504211003785

International Center for Numerical Methods in Engineering (CIMNE), Technical University of Catalonia, Barcelona, Catalunya, Spain.

The morphometry of abdominal aortic aneurysms (AAA) has been recognized as one of the main factors that may predispose them to rupture. The need to quantify the morphometry of AAA on a patient-specific basis constitutes a valuable tool for assisting in rupture risk prediction. Previous results of this research group have determined the correlations between hemodynamic stresses and aneurysm morphometry by means of the Pearson coefficient. Read More

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Acute Hemodynamic Improvement by Thermal Vasodilation inside the Abdominal and Iliac Arterial Segments of Young Sedentary Individuals.

J Vasc Res 2021 Apr 6:1-15. Epub 2021 Apr 6.

Laboratory of Biomechanical Engineering, Department of Applied Mechanics, College of Architecture & Environment, Sichuan University, Chengdu, China.

Objective: To study the hemodynamic response to lower leg heating intervention (LLHI) inside the abdominal and iliac arterial segments (AIAS) of young sedentary individuals.

Methods: A Doppler measurement of blood flow was conducted for 5 young sedentary adults with LLHI. Heating durations of 0, 20, and 40 min were considered. Read More

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Superior Wear-Resistance of TiCT Multilayer Coatings.

ACS Nano 2021 Apr 6. Epub 2021 Apr 6.

Department of Chemical Engineering, Biotechnology and Materials, FCFM, University of Chile, Santiago, 8370415, Chile.

Owing to MXenes' tunable mechanical properties induced by their structural and chemical diversity, MXenes are believed to compete with state-of-the-art 2D nanomaterials such as graphene regarding their tribological performance. Their nanolaminate structure offers weak interlayer interactions and an easy-to-shear ability to render them excellent candidates for solid lubrication. However, the acting friction and wear mechanisms are yet to be explored. Read More

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Greater explosive quadriceps strength is associated with greater knee flexion at initial contact during landing in females.

Sports Biomech 2021 Apr 6:1-15. Epub 2021 Apr 6.

School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA.

This study investigated the influences of explosive quadriceps strength and landing task on sagittal plane knee biomechanics. Forty female participants performed isometric knee extensions on a dynamometer and had lower extremity biomechanics assessed during double-leg jump-landings (DLJL) and single-leg jump-cuts (SLJC). Explosive quadriceps strength was quantified by calculating rate of torque development (RTD) between torque onset and 100 ms after onset on a dynamometer. Read More

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Individual effect of shear rate and oxygen transfer on clavulanic acid production by Streptomyces clavuligerus.

Bioprocess Biosyst Eng 2021 Apr 5. Epub 2021 Apr 5.

Department of Bioprocesses Engineering and Biotechnology, Faculty of Pharmaceutical Sciences, Univ Estadual Paulista "Júlio de Mesquita Filho", Araraquara, SP, CEP 14801-902, Brazil.

The production of biocompounds through the cultivation of filamentous microorganisms is mainly affected by Oxygen Transfer Rate (OTR) and shear rate ([Formula: see text]) conditions. Despite efforts have been made to evaluate the effect of operating variables (impeller speed, N; and airflow rate, ϕ) on clavulanic acid production, no analysis regarding the effect of OTR and [Formula: see text] was made. Then, the aim of this study was to evaluate the dissociated effect of physical phenomena such as oxygen transfer and shear rate in the production of clavulanic acid from Streptomyces clavuligerus using a stirred tank bioreactor. Read More

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An experimental system to evaluate impact shear failure of rock discontinuities.

Rev Sci Instrum 2021 Mar;92(3):034501

School of Geosciences, University of Edinburgh, Edinburgh EH9 3FE, United Kingdom.

Conventionally, the evaluation of shear failure of discontinuities in rocks and other geomaterials has been conducted under static shear loading. In such methods, the shear failure behaviors of rock discontinuities are significantly influenced by loading velocities. To evaluate the shear failure process under dynamic loading, in this paper, we propose a new experimental methodology by taking advantages of recently available high-speed optical and mechanical measurement techniques. Read More

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Numerical approach-based simulation to predict cerebrovascular shear stress in a blood-brain barrier organ-on-a-chip.

Biosens Bioelectron 2021 Mar 26;183:113197. Epub 2021 Mar 26.

Department of Mechanical Engineering, Dong-A University, Busan, 49315, Republic of Korea. Electronic address:

Most of the compounds are impermeable to the blood-brain barrier (BBB), which poses a significant challenge in the development of therapeutics for the treatment of neurological diseases. Most of the existing in vitro BBB models are not capable of mimicking the in vivo conditions and functions. The numerical approach-based simulation model was proposed to accurately predict the in vivo level shear stress for the microfluidic BBB-on-a-chip. Read More

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Clinical performance of two different adhesive strategies for metal-ceramic cracks repairing and related in vitro study.

Dent Mater J 2021 Apr 3. Epub 2021 Apr 3.

Beijing Stomatological Hospital, Capital Medical University.

To evaluate the bonding reliability of a universal adhesive compared to a commercial ceramic repair system for metal-ceramic cracks. In vitro part: sixty specimens with porcelain, metal and porcelain-metal substrate were fabricated. Half specimens were bonded by Singlebond Universal adhesive and Filtek Z350 resin composite. Read More

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Low-temperature 3D printing of collagen and chitosan composite for tissue engineering.

Mater Sci Eng C Mater Biol Appl 2021 Apr 12;123:111963. Epub 2021 Feb 12.

Key Laboratory of Medical Information and 3D Bioprinting of Zhejiang Province, Hangzhou Dianzi University, Hangzhou, China; School of Automation, Hangzhou Dianzi University, Hangzhou, China. Electronic address:

Three-dimensional (3D) printing is a promising method to prepare scaffolds for tissue regeneration. Collagen and chitosan composites are superior materials for tissue engineering scaffold but rarely printed due to their poor printability. Here, we prepared a series of tunable hybrid collagen/chitosan bioinks with significantly improved printability through hydrogen bond interaction and printed them into scaffolds by carefully controlling the temperature. Read More

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Quantitative measure of memory loss in complex spatiotemporal systems.

Chaos 2021 Mar;31(3):033126

Department of Mathematical Sciences, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102, USA.

History dependence of the evolution of complex systems plays an important role in forecasting. The precision of the predictions declines as the memory of the systems is lost. We propose a simple method for assessing the rate of memory loss that can be applied to experimental data observed in any metric space X. Read More

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Effect of the Process Parameters on the Adhesive Strength of Dissimilar Polymers Obtained by Multicomponent Injection Molding.

Polymers (Basel) 2021 Mar 26;13(7). Epub 2021 Mar 26.

Nanotechnology Group, Graduate Program in Industrial Engineering, Polytechnic School, Universidade Federal University of Bahia, R. Aristides Novis 2, 6° Andar, Federação, Salvador 40170-115, Brazil.

The growing demand in the consumer market for products with sustainable technologies has motivated new applications using overmolded natural fiber composites. Therefore, studies have been conducted mainly to understand the adhesive properties of overmolded parts. In the present study, a polypropylene (PP) composite with 30% coconut fibers without additives was developed with the aid of a corotating twin screw extruder. Read More

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Steady and Oscillatory Shear Flow Behavior of Different Polysaccharides with Laponite.

Polymers (Basel) 2021 Mar 22;13(6). Epub 2021 Mar 22.

Department of Chemical Engineering, University of Salamanca, Plaza los Caídos s/n, 37008 Salamanca, SA, Spain.

The rheological behavior, in terms of steady and oscillatory shear flow, of Laponite with different polysaccharides (alginate, chitosan, xanthan gum and levan) in salt-free solutions was studied. Results showed that a higher polymer concentration increased the zero-rate viscosity and decreased the critical strain rate (Cross model fit) as well as increasing the elastic and viscous moduli. Those properties (zero-rate viscosity and critical strain rate) can be a suitable indicator of the effect of the Laponite on the shear flow behavior for the different solutions. Read More

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Liquid-Liquid Flows with Non-Newtonian Dispersed Phase in a T-Junction Microchannel.

Micromachines (Basel) 2021 Mar 22;12(3). Epub 2021 Mar 22.

Kutateladze Insitute of Thermophysics SB RAS, 630090 Novosibirsk, Russia.

Immiscible liquid-liquid flows in microchannels are used extensively in various chemical and biological lab-on-a-chip systems when it is very important to predict the expected flow pattern for a variety of fluids and channel geometries. Commonly, biological and other complex liquids express non-Newtonian properties in a dispersed phase. Features and behavior of such systems are not clear to date. Read More

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