field flow fractionation

We propose a new speckle-based plethysmography technique, termed rolling shutter speckle plethysmography (RSSPG), which can quantitatively measure the velocity and volume fluctuations of blood flow during the cardiac cycle. Our technique is based on the rolling shutter speckle imaging, where the short row-by-row time differences in the rolling shutter image sensors are used to measure the temporal decorrelation behavior of vertically elongated speckles from a single image capture. Temporal analysis of the speckle field provides rich information regarding the dynamics of the scattering media, such as both the dynamic scattering fraction and the speckle decorrelation time...

Computational Fluid Dynamics has become a very powerful tool for developing engineering combustion devices, such as burners and furnaces. However, there are a wide variety of turbulence models, and some of them have proven to be more effective for some turbulent flow configurations than others. A reacting turbulent jet is a common flow configuration found in combustion engineering devices like burners. The present work assesses Reynolds-Average Navier-Stokes turbulence models, being tested on a CH4 /H2 /N2 -Air reacting jet...

Photodynamic therapy (PDT) is a suitable alternative to currently employed cancer treatments. However, the hydrophobicity of most photosensitizers (e.g., zinc phthalocyanine (ZnPC)) leads to their aggregation in blood. Moreover, non-specific accumulation in skin and low clearance rate of ZnPC leads to long-lasting skin photosensitization, forcing patients with a short life expectancy to remain indoors. Consequently, the clinical implementation of these photosensitizers is limited. Here, benzyl-poly(ε-caprolactone)-b-poly(ethylene glycol) micelles encapsulating ZnPC (ZnPC-M) were investigated to increase the solubility of ZnPC and its specificity towards cancers cells...

OBJECTIVE: This article aims to assess the reproducibility of Manufacturer and User Facility Device Experience (MAUDE) data-driven studies by analyzing the data queries used in their research processes. METHODS: Studies using MAUDE data were sourced from PubMed by searching for "MAUDE" or "Manufacturer and User Facility Device Experience" in titles or abstracts. We manually chose articles with executable queries. The reproducibility of each query was assessed by replicating it in the MAUDE Application Programming Interface...

The unique properties of resistant starch (RS) have made it applicable in the formulation of a broad range of functional foods. The physicochemical properties of RS play a crucial role in its applications. Recently, flow field-flow fractionation (FlFFF) has attracted increasing interest in the separation and characterization of different categories of RS. In this review, an overview of the theory behind FlFFF is introduced, and the controllable factors, including FlFFF channel design, sample separation conditions, and the choice of detector, are discussed in detail...

Non-Newtonian fluid flow is significant in engineering and biomedical applications such as thermal exchangers, electrical cooling mechanisms, nuclear reactor cooling, drug delivery, blood flow analysis, and tissue engineering. The Caputo operator has emerged as a prevalent tool in fractional calculus, garnering widespread recognition. This research aims to introduce a novel derivative by merging the proportional and Caputo operators, resulting in the fractional operator known as the constant proportional Caputo...

In order to control NO x emissions and meet China's ultralow emission standards, a numerical simulation based on the computational fluid dynamics (CFD) approach is performed for the optimization of the reductant injection volume, number of injection sources, distribution, and injection direction for the flue gas denitrification process of a circulating fluidized bed boiler (CFB) blended with low-water content biomass in a 168 MW unit of a thermal power plant. Using the target power plant boiler entity as a template, a simplified geometric model is established, 1:1, and the mass fractions of each flue gas component set by the inlet boundary conditions are O2 2, H2 O11...

Using a small deformation approach, a fractional ordinary differential system is proposed to investigate the motion and deformation of a vesicle in shear flow. Closed analytical expressions of the orientation angle and the ellipticity of the vesicle contour (shape deformation) are provided. Three different motions are identified, the classical tank-treading state, and two new types of motions, namely, the over-damped tank-treading mode, in which the vesicle's orientation angle ψ and its shape deformation R tend more slowly toward equilibrium, and the under-damped tank-treading mode, in which ψ oscillates all the time along the flow direction with decreasing amplitude, while R starts making a breathing motion and then tends to an attractive amplitude...

Abnormal oxygen extraction fraction (OEF), a putative biomarker of cerebral metabolic stress, may indicate compromised oxygen delivery and ischemic vulnerability in patients with sickle cell disease (SCD). Elevated OEF was observed at the tissue level across the brain using an asymmetric spin echo (ASE) MR method, while variable global OEFs were found from the superior sagittal sinus (SSS) using a T2-relaxation-under-spin-tagging (TRUST) MRI method with different calibration models. In this study, we aimed to compare the average ASE-OEF in the SSS drainage territory and TRUST-OEF in the SSS from the same SCD patients and healthy controls...

Chromatographers often employ fully aqueous mobile phases to retain highly polar compounds in reversed-phase liquid chromatography (RPLC). However, when the flow rate is interrupted, either accidentally or intentionally, a substantial loss in retention occurs due to the spontaneous dewetting of water from the hydrophobic surface of conventional RPLC-C18 particles. Previous studies have shown that maintaining a low C18 surface coverage (approximately 1.5 μmol/m2 ) can mitigate water dewetting by increasing chain disorder, facilitating the intercalation of water clusters between the C18 -bonded chains, and keeping the mesopores wetted...

The rheology of particle suspensions has been extensively explored in the case of a simple shear flow, but less in other flow configurations which are also important in practice. Here we investigate the behavior of a suspension in a squeeze flow, which we revisit using local pressure measurements to deduce the effective viscosity. The flow is generated by approaching a moving disk to a fixed wall at constant velocity in the low Reynolds number limit. We measure the evolution of the pressure field at the wall and deduce the effective viscosity from the radial pressure drop...

The successful demonstration of long-lived nitric oxide (NO) fluorescence for molecular tagging velocimetry (MTV) measurements is described in this Letter. Using 1 + 1 resonance-enhanced multiphoton ionization (REMPI) of NO at a wavelength near 226 nm, targeting the overlapping Q1 (7) and Q21 (7) lines of the A-X (0, 0) electronic system, the lifetime of the NO MTV signal was observed to be approximately 8.6 µs within a 100-Torr cell containing 2% NO in nitrogen. This is in stark contrast to the commonly reported single photon NO fluorescence, which has a much shorter calculated lifetime of approximately 43 ns at this pressure and NO volume fraction...

The current letter to the editor describes the presence of RNA byproducts in small-scale in vitro transcription (IVT) reactions as evaluated by capillary gel electrophoresis, asymmetric flow field flow fractionation, immunoblotting, cell-free translation assays, and in IFN reporter cells. We compare standard T7 RNA polymerase (RNAP) based IVT reactions to two recently described protocols employing either urea supplementation or using the VSW3 RNAP. Our results indicate that urea supplementation yields considerably less RNA byproducts and positively affects the overall number of full-length transcripts...

Nanoplastics (NPs) have been identified as an emerging concern for the environment and our food chains in recent years. Monitoring the concentration and size of nanoplastics is essential to assess the potential risks that nanoplastic particles may pose. In this study, we presented a multi-technique based analytical platform to identify, characterize and quantify nanoplastics in water samples through a combination of sample pre-concentration, asymmetric flow field-flow fractionation coupled with multi-angle light scattering (AF4-MALS) and pyrolysis-GC/MS (Py-GC/MS)...

The physics governing the fluid dynamics of bio-inspired flapping wings is effectively characterized by partial differential equations (PDEs). Nevertheless, the process of discretizing these equations at spatiotemporal scales is notably time consuming and resource intensive. Traditional PDE-based computations are constrained in their applicability, which is mainly due to the presence of numerous shape parameters and intricate flow patterns associated with bionic flapping wings. Consequently, there is a significant demand for a rapid and accurate solution to nonlinear PDEs, to facilitate the analysis of bionic flapping structures...

The primary goal of this investigation is to examine the heat and flow characteristics of a hybrid nanofluid consisting of silver (Ag) and aluminum oxide (Al[Formula: see text]O[Formula: see text] nanoparticles over an unsteady radially stretching sheet embedded in porous medium. The investigation is conducted under the influence of several key parameters, namely joule heating, viscous dissipation, porous, slip, and suction. The technique of similarity transformations is used to transform the governing system of PDEs into nonlinear ODEs and the bvp4c solver is used to solve them numerically...

BACKGROUND: In treating atrial fibrillation, pulsed-field ablation (PFA) has comparable efficacy to conventional thermal ablation, but with important safety advantages: no esophageal injury or pulmonary vein stenosis, and rare phrenic nerve injury. However, when PFA is delivered in proximity to coronary arteries using a pentaspline catheter, which generates a broad electrical field, severe vasospasm can be provoked. OBJECTIVES: The authors sought to study the vasospastic potential of a focal PFA catheter with a narrower electrical field and develop a preventive strategy with nitroglycerin...

Surfactant/polymer flooding allows for a significant increase in oil recovered at both laboratory and field scales. Limitations in application at the reservoir scale are, however, present and can be associated with both the complexity of the underlying displacement process and the time-intensive nature of the up-scaling workflow. Pivotal to this workflow are corefloods which serve to both validate the extent of oil recovery and extract modeling parameters used in upscaling. To enhance the understanding of the evolution of the saturation distribution within the rock sample, we present the utilization of X-ray computed tomography to image six distinct surfactant/polymer corefloods...

Strontium (Sr) removal from water is required because excessive naturally occurring Sr exposure is hazardous to human health. Climate and seasonal changes cause water quality variations, in particular quality and quantity of organic matter (OM) and pH, and such variations affect Sr removal by nanofiltration (NF). The mechanisms for such variations are not clear and thus OM complexation and speciation require attention. Sr removal by NF was investigated with emphasis on the role of OM (type and concentration) and pH (2-12) on possible removal mechanisms, specifically size and/or charge exclusion as well as solute-solute interactions...

Extracellular vesicles (EVs) hold immense potential for various biomedical applications, including diagnostics, drug delivery, and regenerative medicine. Nevertheless, the current methodologies for isolating EVs present significant challenges, such as complexity, time consumption, and the need for bulky equipment, which hinders their clinical translation. To address these limitations, we aimed to develop an innovative microfluidic system based on cyclic olefin copolymer-off-stoichiometry thiol-ene (COC-OSTE) for the efficient isolation of EVs from large-volume samples in a continuous manner...