AI Article Synopsis

  • The study examines how the movements of passive particles can reveal properties of active fluids, such as bacterial baths or molecular assemblies, particularly when these particles are confined in spherical droplets.
  • The dynamics of a negatively buoyant probe particle in an active fluid is modeled using colored stochastic noise, characterized by intensity and memory time, while also approximating its movement as occurring in a two-dimensional harmonic trap.
  • By numerically simulating the particle's dynamics and analyzing its mean square displacement, the researchers can extract the activity parameters of the fluid, achieving reliable results under conditions of low noise intensity in confinement.

Article Abstract

The properties of an active fluid, for example, a bacterial bath or a collection of microtubules and molecular motors, can be accessed through the dynamics of passive particle probes. Here, in the perspective of analyzing experimental situations of confinement in droplets, we consider the kinematics of a negatively buoyant probe particle in an active fluid, both confined within a spherical domain. The active bath generates a fluctuating flow that pushes the particle with a velocity that is modeled as a colored stochastic noise, characterized by two parameters, the intensity and memory time of the active flow. When the particle departs a little from the bottom of the spherical domain, the configuration is well approximated by a particle in a two-dimensional harmonic trap subjected to the colored noise, in which case an analytical solution exists, which is the base for quantitative analysis. We numerically simulate the dynamics of the particle and use the planar, two-dimensional mean square displacement to recover the activity parameters of the bath. This approach yields satisfactory results as long as the particle remains relatively confined; that is, as long as the intensity of the colored noise remains low.

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevE.110.014610DOI Listing

Publication Analysis

Top Keywords

active fluid
12
activity parameters
8
fluid confined
8
spherical domain
8
colored noise
8
particle
7
active
5
recovering activity
4
parameters active
4
confined sphere
4

Similar Publications

A Wet-Adhesion and Swelling-Resistant Hydrogel for Fast Hemostasis, Accelerated Tissue Injury Healing and Bioelectronics.

Adv Mater

December 2024

Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, School of Chemistry, Xi'an Jiaotong University, Xi'an, 710049, China.

Hydrogel bioadhesives with adequate wet adhesion and swelling resistance are urgently needed in clinic. However, the presence of blood or body fluid usually weakens the interfacial bonding strength, and even leads to adhesion failure. Herein, profiting from the unique coupling structure of carboxylic and phenyl groups in one component (N-acryloyl phenylalanine) for interfacial drainage and matrix toughening as well as various electrostatic interactions mediated by zwitterions, a novel hydrogel adhesive (PAAS) is developed with superior tissue adhesion properties and matrix swelling resistance in challenging wet conditions (adhesion strength of 85 kPa, interfacial toughness of 450 J m, burst pressure of 514 mmHg, and swelling ratio of <4%).

View Article and Find Full Text PDF

In the present study, porous calcium alginate films have been developed by the addition of 0.02, 0.1, and 0.

View Article and Find Full Text PDF

Two live attenuated vaccines (LAVs), LMA and LMP, were evaluated alone or in combination with a trivalent adenoviral vector-based vaccine (Ad5-YFV) for their efficacy and immune responses in wild type (WT) and interferon gamma (IFNγ) knockout (KO) mice in a C57BL/6 background. While LMA and LMP are triple deletion mutants of CO92 strain, Ad5-YFV incorporates three protective plague immunogens. An impressive 80-100% protection was observed in all vaccinated animals against highly lethal intranasal challenge doses of parental CO92.

View Article and Find Full Text PDF

While earlier post-mortem studies show involvement of the central nervous system in 71% of patients with chronic lymphocytic leukemia (CLL), involvement intravitam is rare. A 72-year-old man with untreated, minimally symptomatic CLL developed subacute-onset encephalopathy and presented with severe hyponatremia and stress-induced cardiomyopathy. His initial head computed tomography scan was unremarkable.

View Article and Find Full Text PDF

Hypercalcemia is a common electrolyte disturbance, most frequently caused by hyperparathyroidism or malignancy, though it can also arise from adrenal insufficiency, creating diagnostic challenges. We present a case of a 78-year-old male patient with stage 3b chronic kidney disease due to immunoglobulin A nephropathy who exhibited altered mental status following dehydration caused by a five-day episode of diarrhea. The patient presented with hypercalcemia and acute kidney injury.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!