Abstract We wished to longitudinally assess early changes in cerebral perfusion (CP) and its relationship to cognitive impairment (CI) in ALS. Fourteen ALS patients at time of diagnosis and 11 spousal controls, both without CI, were longitudinally assessed to determine a relationship between CP and incidence of CI in early ...

Pleural TB is notoriously difficult to diagnose due to its paucibacillary nature yet it is the most common cause of pleural effusions in TB endemic countries such as The Gambia. We identified both cellular and soluble biomarkers in the pleural fluid that allowed highly accurate diagnosis of pleural TB compared ...

Purpose: To prospectively determine whether fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) early dynamic blood flow estimates could be used to discriminate hepatocellular carcinoma (HCC) from background liver and to characterize HCC in patients with and those without angioinvasion; and to evaluate the association between blood flow ...

Coronary Flow Reserve (CFR) is an important index of coronary microcirculatory function. The objective of this study was to validate the reproducibility and accuracy of intravascular conductance catheter-based method for measurements of baseline and hyperemic coronary flow velocity (and hence CFR). The absolute coronary blood velocity was determined by measuring ...

The esophagus spans three body cavities and has no mesentery, continually borrowing or sharing vessels, lymphatics, and nerves with associated organs. However, constant along this path is an intricate mural structure. An understanding of the esophageal wall, its blood supply, lymphatic drainage, and innervation is essential for successful esophageal surgery.

Polyvinyl alcohol cryogel (PVA-C) is presented as a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10% wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with antibacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1-6 freeze-thaw cycles. The resulting ...

To test the ability of a multi-band RF pulse to reduce flow enhancement artifacts for steady state imaging without compromising temporal resolution or spatial coverage. Selectively spoiled composite RF pulses that provide simultaneous excitation and flow preparation were designed and tested by means of simulation, phantom, and in vivo measurements ...

On microstructured hydrophobic surfaces, geometrical patterns may lead to the appearance of a superhydrophobic state, where gas bubbles at the surface can have a strong impact on the fluid flow along such surfaces. In particular, they can strongly influence a detected slip at the surface. We present two-phase lattice Boltzmann ...

Three EBA specified blood bag configurations ('Eurobloodpack') are described which are capable of meeting >80% of its member's requirements. These include a 'top-and-top' and two 'bottom-and-top' packs enabling aseptic, pre-donation collection of up to 40 ml of samples, 427·5-522·5 ml of whole blood and the preparation of an extensive range of blood ...

Many flow visualization techniques, especially integration-based methods, are problematic when the measured data exhibits noise and discretization issues. Particularly, this is the case for flow-sensitive phase-contrast magnetic resonance imaging (PC-MRI) datasets which not only record anatomic information but also time-varying flow information. We propose a novel approach for the visualization ...

The flow behavior of a commercial polymeric monolith was investigated by direct numerical simulations employing the lattice-Boltzmann (LB) methodology. An explicit structural representation of the monolith was obtained by serial sectioning of a portion of the monolith and imaging by scanning electron microscopy. After image processing, the three-dimensional structure of ...

Objectives: The goal of this study was to enhance the blood responses to titanium (Ti) surfaces used for dental implant application through the formation of a TiO(2) nano-mesh surface layer produced by a fast electrochemical anodization treatment. Material and methods: Electrochemical anodization treatments with different anodization currents and temperatures in ...

To assess the accuracy of human blood oximetry measurements in a model eye with a hyperspectral fundus camera. Seven human whole blood samples (two arterial, five venous) were obtained, the oxygen saturations measured with a CO oximeter, and the samples inserted into quartz tubes with internal diameters of 100 and ...

This study is part of a FDA-sponsored project to evaluate the use and limitations of computational fluid dynamics (CFD) in assessing blood flow parameters related to medical device safety. In an interlaboratory study, fluid velocities and pressures were measured in a nozzle model to provide experimental validation for a companion ...

In this paper, numerical simulations are used to study the turbulent wind noise reduction effect of microphone windscreens with varying shapes and flow resistivities. Typical windscreen shapes consisting of circular, elliptical, and rectangular cylinders are investigated. A turbulent environment is generated by placing a solid circular cylinder upstream of the ...

An early determination of pulpal vitality is crucial with respect to a correct differential diagnosis of revascularisation or necrosis and its treatment. Sensibility tests (cold, heat, electrical pulp test) in combination with radiographs are commonly promoted. However these tests are arbitrary, based on sensations and therefore not always reliable. In ...

To systematically investigate the scan-rescan reproducibility and observer variability of flow-sensitive four-dimensional (4D) MRI in the aorta for the assessment of blood flow and global and segmental wall shear stress. ECG and respiration-synchronized flow-sensitive 4D MRI data (spatio-temporal resolution = 1.7 × 2.0 × 2.2 mm(3) /40.8 ms) were acquired ...

Abstract Wright-Giemsa staining is a common procedure that is performed routinely in hematology laboratories. Consistency in intra-laboratory staining quality is essential for accurate morphological interpretation of blood smears. Although the Wright-Giemsa stain can be challenging to perform, the methods illustrated here have provided consistent, high quality stains in the Special ...

Abstract Eocene ocean currents and prevailing winds correlate with over-water dispersals of terrestrial mammals from Africa to Madagascar. Since the Early Miocene (about 23 Ma), these currents flowed in the reverse direction, from the Indian Ocean towards Africa. The Comoro Islands are equidistant between Africa and Madagascar and support an endemic ...

The permeability of gases through uncompressed cork was investigated. More than one hundred samples were assessed from different plank qualities to provide a picture of the permeability distribution. A novel technique based on a mass spectrometer leak detector was used to directly measure the helium flow through the central area ...

Recharge through intermittent and ephemeral stream channels is believed to be a primary aquifer recharge process in arid and semiarid environments. The intermittent nature of precipitation and flow events in these channels, and their often remote locations, makes direct flow and loss measurements difficult and expensive. Airborne and satellite optical ...

OBJECTIVE: The Non-pneumatic Antishock Garment (NASG) is a compression device that has shown significantly decreased blood loss in cases of obstetric hemorrhage. However, there are no physiologic studies of the NASG in postpartum women. This study used Doppler ultrasound to measure the resistive index (RI) in the internal iliac artery, ...

The purpose of this article is to validate numerical simulations of flow and pressure incorporating deformable walls using in vitro flow phantoms under physiological flow and pressure conditions. We constructed two deformable flow phantoms mimicking a normal and a restricted thoracic aorta, and used a Windkessel model at the outlet ...

Introduction:  ROTEM(®) is considered a helpful point-of-care device to monitor blood coagulation. Centrally performed analysis is desirable but rapid transport of blood samples and real-time transmission of graphic results are an important prerequisite. The effect of sample transport through a pneumatic tube system on ROTEM(®) results is unknown. The aims ...

Objectives: To create a low-cost protocol for the production of autologous serum eye drops (ASEs) by blood collection and processing centres using standard equipment and staff already available. The protocol must observe local and federal regulatory authorities' requirements for good manufacturing practice. Aim: The final aim is to improve accessibility ...

Flow and stresses induced by blood flow acting on the blood cellular constituents can be represented to a certain extent by a continuum mechanics approach down to the order of the μm level. However, the molecular effects of, e.g., adhesion/aggregation bonds of blood clotting can be on the order of nm. ...

Passive samplers for phosphate were calibrated in the laboratory over a range of flow velocities (0-27 cm s(-1)) and ionic strengths (0-0.62 mol kg(-1)). The observed sampling rates were between 0.006 and 0.20 L d(-1). An empirical model allowed the estimation of these sampling rates with a precision of 8.5%. ...

Many processes in geophysical and industrial settings involve the flow of granular materials down a slope. In order to investigate the granular dynamics, we report a series of laboratory experiments conducted by releasing grains at a steady rate from a localized source on a rough inclined plane. Different types of ...

PURPOSE: To estimate surface-based wall shear stress (WSS) and evaluate flow patterns in ascending aortic dilatation (AscAD) using a high-resolution, time-resolved, three-dimensional (3D), three-directional velocity encoded, radially undersampled phase contrast magnetic resonance sequence (4D PC-MRI). MATERIALS AND METHODS: 4D PC-MRI was performed in 11 patients with AscAD (46.3±22.0 years) and ...

Background  Therapeutic effects have been attributed to far-infrared (FIR) radiation emitted from different types of sources. One class of such infrared emitters consists of ceramics in a powdered form, which allows for its incorporation into creams and fabrics. Such ceramic materials emit in the FIR when subjected to body temperature. ...

The global stability of the steady jetting mode of liquid jets focused by coaxial gas streams is analyzed both theoretically and experimentally. Numerical simulations allow one to identify the physical mechanisms responsible for instability in the low viscosity and very viscous regimes of the focused liquid. The characteristic flow rates ...

The objective of this work is to investigate the effect of non-Newtonian properties of blood on the wall shear stress (WSS) in atherosclerotic coronary arteries using both Newtonian and non-Newtonian models. Numerical simulations were performed to examine how the spatial and temporal WSS distributions are influenced by the stenosis size, ...

An Allegretto Eye-Q laser platform (Wavelight GmbH, Erlangen, Germany) was used to study the effect of air-flow speed on the ablation of artificial polymer corneas used for testing refractive surgery patterns. Flat samples of two materials (PMMA and Filofocon A) were ablated at four different air flow conditions. The shape ...

PURPOSE: Duplex surveillance of arterial stents has focused on detecting in-stent restenosis. Although velocity is commonly reported, that differs from blood flow, and patency of arterial prostheses is flow-dependent. Preliminary evaluation was performed to determine if postprocedure peak systolic blood flow (PSF) through stents correlates with rate of repeat intervention ...

The behaviour of droplets entering a microfluidic chamber designed to house microelectrode detectors for real time analysis of clinical microdialysate is described. We have designed an analysis chamber to collect the droplets produced by multiphase flows of oil and artificial cerebral spinal fluid. The coalescence chamber creates a constant aqueous ...

It is well known that red blood cell scattering has an impact on whole blood oximetry as well as in vivo retinal oxygen saturation measurements. The goal of this study was to quantify the impact of small angle forward scatter on whole blood oximetry for scattering angles found in retinal ...

A novel method has been devised to derive kinetic information about reactions in microfluidic systems. Advantages have been demonstrated over conventional procedures for a Knoevenagel condensation reaction in terms of the time required to obtain the data (fivefold reduction) and the efficient use of reagents (tenfold reduction). The procedure is ...

Objective: The hemodynamics in proximity to stented aortic bioprostheses still differ from that under physiological conditions. This may prevent desired cardiac remodeling and promote aortic diseases. Further improvements in prosthetic technology require an accurate survey of the flow conditions on the prosthetic level and in the ascending aorta. Cardiovascular magnetic ...

At the boundary between a hydrophilic and hydrophobic surface coating a large contact angle hysteresis exists which can be used to retain fluid on a flat surface, a similar effect exists at the edge of a solid surface. In this work, pressure-driven flow is used to create fluid flow through ...

Traditional commercial stents are made of wires with square or semi-circular cross-sections that lead to flow disturbance, which plays an important role in the initiation and progression of restenosis. A new stent with streamlined cross-sectional wires was proposed and researched numerically for its hemodynamic performance. Simplified models of stents with ...

BACKGROUND: Although multiple echocardiographic methods exist to calculate cardiac output (CO), they have not been validated in mice using a reference method. METHODS: Echocardiographic and flow probe measurements of CO were obtained in mice before and after albumin infusion and inferior vena cava occlusions. Echocardiography was also performed before and ...

A new computer program, FLASH (Flow-Log Analysis of Single Holes), is presented for the analysis of borehole vertical flow logs. The code is based on an analytical solution for steady-state multilayer radial flow to a borehole. The code includes options for (1) discrete fractures and (2) multilayer aquifers. Given vertical ...

High resolution in vivo velocity measurements within the cardiovascular system are essential for accurate calculation of vessel wall shear stress, a highly influential factor for the progression of arterial disease. Unfortunately, currently available techniques for in vivo imaging are unable to provide the temporal resolution required for velocity measurement at ...

Air-flow resistivity is a main parameter governing the acoustic behavior of porous materials for sound absorption. The international standard ISO 9053 specifies two different methods to measure the air-flow resistivity, namely a steady-state air-flow method and an alternating air-flow method. The latter is realized by the measurement of the sound ...

Ultrasonic backscatter has recently been used extensively to investigate erythrocyte aggregation, which is an inherent hematological phenomenon in the blood circulation system. The size of rouleaux can be estimated by measuring certain parameters of signals backscattered from flowing blood. However, most measurements of backscatter from blood use a constant value ...

Objective-To compare the ease of use and accuracy of 5 feline AB blood-typing methods: card agglutination (CARD), immunochromatographic cartridge (CHROM), gel-based (GEL), and conventional slide (SLIDE) and tube (TUBE) agglutination assays. Sample Population-490 anticoagulated blood samples from sick and healthy cats submitted to the Transfusion or Clinical Laboratory at the ...

In a recent paper [F. Vega Reyes et al., Phys. Rev. Lett. 104, 028001 (2010)] we presented a preliminary description of a special class of steady Couette flows in dilute granular gases. In all flows of this class the viscous heating is exactly balanced by inelastic cooling. This yields a ...

To evaluate the signal properties of 2D time of flight (TOF), quiescent-interval single-shot (QISS), ECG-gated 3D fast spin-echo (FBI), and ungated 3D fast spin-echo ghost (Ghost) magnetic resonance angiography (MRA) over a range of flow velocities in a pulsatile flow phantom with a 50% diameter stenosis at 1.5T. Blood-mimicking fluid ...

We develop and validate an efficient lattice kinetic Monte Carlo (LKMC) method for simulating particle aggregation in laminar flows with spatially varying shear rate, such as parabolic flow or flows with standing vortices. A contact time model was developed to describe the particle-particle collision efficiency as a function of the ...

Cutaneous red blood cell velocity in vivo can be measured by using capillaroscopy with image processing techniques. However, unlike simulated blood flow images, there is no standard to determine the accuracy of the techniques for computing blood flow velocities. In this paper, we quantitatively evaluated the accuracy of previously proposed ...