728 results match your criteria: "UMR 7057 CNRS & Universite Paris Diderot[Affiliation]"

Extracellular vesicles (EVs)─including exosomes and microvesicles─are involved in cell-cell communication. EVs encapsulate different types of molecules such as proteins or nucleotides and are long-lasting contenders for the establishment of personalized drug delivery systems. Recent studies suggest that the intrinsic capacities for uptake and cargo delivery of basic EVs might be too limited to serve as a potent delivery system.

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The application of aseismic materials in foundation engineering structures is an inevitable trend and research hotspot of earthquake resistance, especially in tunnel engineering. In this study, the pelican optimization algorithm (POA) is improved using the Latin hypercube sampling (LHS) method and the Chaotic mapping (CM) method to optimize the random forest (RF) model for predicting the aseismic performance of a novel aseismic rubber-concrete material. Seventy uniaxial compression tests and seventy impact tests were conducted to quantify this aseismic material performance, i.

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Bending Actuation of Hydrogels through Rotation of Light-Driven Molecular Motors.

Angew Chem Int Ed Engl

March 2023

SAMS Research Group, Université de Strasbourg, CNRS, Institut Charles Sadron UPR 22, 67000, Strasbourg, France.

The unidirectional rotation of chemically crosslinked light-driven molecular motors is shown to progressively shift the swelling equilibrium of hydrogels. The concentration of molecular motors and the initial strand density of the polymer network are key parameters to modulate the macroscopic contraction of the material, and both parameters can be tuned using polymer chains of different molecular weights. These findings led to the design of optimized hydrogels revealing a half-time contraction of approximately 5 min.

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Motions of a dimer on a periodic potential.

Phys Rev E

December 2022

Laboratoire "Matière et Systèmes Complexes" (MSC), UMR 7057 CNRS, Université Paris-Diderot (Paris 7), 75205 Paris Cedex 13, France.

A dimer on a periodic potential is a simple system that exhibits a surprisingly rich dynamics. This system is conservative, but it is nonlinear and nonintegrable. In a previous work, we evidenced the autoparametric excitation of the relative motion by the center of mass in two limiting cases (very small or very large initial energy, compared to the external potential depth).

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Extracellular vesicles (EVs) are biological vehicles that are thought to mediate cell-cell communication via the transfer of biomolecules from donor to acceptor cells. Repurposing those natural vesicles into therapeutics delivery vectors is a high priority challenge for translational science. Here we engineer donor cells to produce copious amount of fusogenic EVs loaded with the catalytic domain of the Diphteria Toxin, known to trigger cell death through protein synthesis inhibition.

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Embryonic Development of Motility: Lessons from the Chicken.

Adv Exp Med Biol

January 2023

Laboratoire Matière et Systèmes Complexes, Université Paris Cité, CNRS UMR 7057, Paris, France.

I outline here the development of intestinal motility in the chicken embryo. The first contractile events are circular smooth muscle driven calcium waves (E6), that gain a clock-like regularity when interstitial cells of Cajal become electrically active (E14). Soon after longitudinal smooth muscle contractions become prominent (E14), the enteric nervous system starts controlling motility (E16) by coupling the longitudinal and circular contractions via inhibitory neurotransmission.

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Article Synopsis
  • - The study investigates how the stiffness of soil affects the growth and cell development of plant roots and root hair cells, an important research area in plant biology.
  • - A new method called the microfluidic-like system (MLS) is introduced, allowing researchers to grow plantlets in gels of varying stiffness over extended periods while observing them via microscopy.
  • - MLS combines benefits of microfluidic technology such as precise control over growth conditions and high-resolution imaging, facilitating long-term quantitative research on how environmental rigidity influences root growth and cellular responses.
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Neuronal cultures are a prominent experimental tool to understand complex functional organization in neuronal assemblies. However, neurons grown on flat surfaces exhibit a strongly coherent bursting behavior with limited functionality. To approach the functional richness of naturally formed neuronal circuits, here we studied neuronal networks grown on polydimethylsiloxane (PDMS) topographical patterns shaped as either parallel tracks or square valleys.

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Flocking in one dimension: Asters and reversals.

Phys Rev E

November 2022

Sorbonne Université, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, 75005 Paris, France.

We study the one-dimensional active Ising model in which aligning particles undergo diffusion biased by the signs of their spins. The phase diagram obtained varying the density of particles, their hopping rate, and the temperature controlling the alignment shows a homogeneous disordered phase but no homogeneous ordered one, as well as two phases with localized dense structures. In the flocking phase, large ordered aggregates move ballistically and stochastically reverse their direction of motion.

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Accumulating evidences suggest a strong correlation between metabolic changes and neurodegeneration in CNS demyelinating diseases such as multiple sclerosis (MS). Biotin, an essential cofactor for five carboxylases, is expressed by oligodendrocytes and involved in fatty acid synthesis and energy production. The metabolic effect of biotin or high-dose-biotin (MD1003) has been reported on rodent oligodendrocytes in vitro, and in neurodegenerative or demyelinating animal models.

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Proteoid biodynamers for safe mRNA transfection via pH-responsive nanorods enabling endosomal escape.

J Control Release

January 2023

Helmholtz Institute for Pharmaceutical Research Saarland (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus E 8.1, 66123 Saarbrücken, Germany; Department of Pharmacy, Saarland University, 66123 Saarbrücken, Germany. Electronic address:

The recent success of mRNA vaccines using lipid-based vectors highlights the importance of strategies for nucleotide delivery under the pandemic situation. Although current mRNA delivery is focused on lipid-based vectors, still they need to be optimized for increasing stability, targeting, and efficiency, and for reducing toxicity. In this regard, other vector systems featuring smart strategies such as pH-responsive degradability and endosomal escape ability hold the potential to overcome the current limitations.

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We study the spreading of droplets in a near-critical phase-separated liquid mixture, using a combination of experiments, lubrication theory and finite-element numerical simulations. The classical Tanner's law describing the spreading of viscous droplets is robustly verified when the critical temperature is neared. Furthermore, the microscopic cut-off length scale emerging in this law is obtained as a single free parameter for each given temperature.

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Liquid and elastic behaviours of tissues drive their morphology and response to the environment. They appear as the first insight into tissue mechanics. We explore the role of individual cell properties on spheroids of mouse muscle precursor cells and investigate the role of intermediate filaments on surface tension and Young's modulus.

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Phenotyping polarization dynamics of immune cells using a lipid droplet-cell pairing microfluidic platform.

Cell Rep Methods

November 2022

École Normale Supérieure, UMR 8640, Laboratoire PASTEUR, Département de Chimie, PSL Research University, Sorbonne Université, CNRS, 75005 Paris, France.

Article Synopsis
  • The immune synapse is the area where special immune cells called lymphocytes connect with other cells to signal and fight off infections.
  • Scientists used cool technology to study how this connection affects how the immune cells work.
  • They found that different things like how much of a signal is present and how strong the surface is can change how the immune cells respond and work together.
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Many ramified, network-like patterns in nature, such as river networks or blood vessels, form as a result of unstable growth of moving boundaries in an external diffusive field. Here, we pose the inverse problem for the network growth-can the growth dynamics be inferred from the analysis of the final pattern? We show that by evolving the network backward in time one can not only reconstruct the growth rules but also get an insight into the conditions under which branch splitting occurs. Determining the growth rules from a single snapshot in time is particularly important for growth processes so slow that they cannot be directly observed, such as growth of river networks and deltas or cave passages.

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D-π-A-Type Pyrazolo[1,5-]pyrimidine-Based Hole-Transporting Materials for Perovskite Solar Cells: Effect of the Functionalization Position.

Materials (Basel)

November 2022

Laboratoire de Physico-Chimie des Matériaux et des Electrolytes pour l'Energie (EA 6299), Université de Tours, Parc de Grandmont, 37200 Tours, France.

Donor−acceptor (D−A) small molecules are regarded as promising hole-transporting materials for perovskite solar cells (PSCs) due to their tunable optoelectronic properties. This paper reports the design, synthesis and characterization of three novel isomeric D-π-A small molecules PY1, PY2 and PY3. The chemical structures of the molecules consist of a pyrazolo[1,5-a]pyrimidine acceptor core functionalized with one 3,6-bis(4,4′-dimethoxydiphenylamino)carbazole (3,6-CzDMPA) donor moiety via a phenyl π-spacer at the 3, 5 and 7 positions, respectively.

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Dynamics of early stages of nose morphogenesis.

Eur Phys J E Soft Matter

November 2022

Laboratoire Matière et Systèmes Complexes, Université de Paris Cité/CNRS UMR 7057, 10 Rue Alice Domont et Léonie Duquet, 75013, Paris, France.

The formation of sensory organs is an important developmental and evolutionary question. In the context of regenerative medicine also, it is important to know as accurately as possible how sensory organs form. The formation of ears, eyes or nose stems presumably from tissue thickenings called placodes Graham and Shimeld (J Anat 222(1):32-40, 2013), Horie et al.

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Passive objects in confined active fluids: A localization transition.

Phys Rev E

October 2022

Université Paris Cité, Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, F-75205 Paris, France.

We study how walls confining active fluids interact with asymmetric passive objects placed in their bulk. We show that the objects experience nonconservative long-ranged forces mediated by the active bath. To leading order, these forces can be computed using a generalized image theorem.

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Arsenic Analysis in the Petroleum Industry: A Review.

ACS Omega

November 2022

Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Technopôle Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex 09, France.

The presence of arsenic in natural gas and liquid hydrocarbons is of great concern for oil companies. In addition to health risks due to its toxicity as well as environmental issues, arsenic is responsible for irreversible poisoning of catalysts and clogging of pipes via the accumulation of As-containing precipitates. To address these problems and to better design treatment units, robust methods for the analysis of arsenic and its compounds in oil streams are required.

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In the present manuscript, we describe how we successfully used ligand-based virtual screening (LBVS) to identify two small-molecule, drug-like hit classes with excellent ADMET profiles against the difficult to address microbial enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXPS). In the fight against antimicrobial resistance (AMR), it has become increasingly important to address novel targets such as DXPS, the first enzyme of the 2--methyl-d-erythritol-4-phosphate (MEP) pathway, which affords the universal isoprenoid precursors. This pathway is absent in humans but essential for pathogens such as , making it a rich source of drug targets for the development of novel anti-infectives.

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Mapping cell cortex rheology to tissue rheology and vice versa.

Phys Rev E

September 2022

Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS and Université Paris Cité, 75205 Paris cedex 13, France.

The mechanics of biological tissues mainly proceeds from the cell cortex rheology. A direct, explicit link between cortex rheology and tissue rheology remains lacking, yet would be instrumental in understanding how modulations of cortical mechanics may impact tissue mechanical behavior. Using an ordered geometry built on 3D hexagonal, incompressible cells, we build a mapping relating the cortical rheology to the monolayer tissue rheology.

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Aggregates of charged metal particles obtained by electrostatic coupling with a compound of opposite charge in the vicinity of the net zero charge ratio are of interest in the field of plasmonics because the inter-particle distance is minimal, which favours plasmonic coupling. However, these structures present a low colloidal stability limiting the development of applications. In this article we show that globally neutral aggregates formed by electrostatic complexation of citrate-stabilized gold particles and a quaternized chitosan (i.

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Fate and biological impact of persistent luminescence nanoparticles after injection in mice: a one-year follow-up.

Nanoscale

November 2022

Université Paris Cité, CNRS, INSERM, UTCBS, Unité de Technologies Chimiques et Biologiques pour la Santé, Faculté de Pharmacie, 75006 Paris, France.

Persistent luminescence nanoparticles (PLNPs) are attracting growing interest for non-invasive optical imaging of tissues with a high signal to noise ratio. PLNPs can emit a persistent luminescence signal through the tissue transparency window for several minutes, after UV light excitation before systemic administration or directly through visible irradiation, allowing us to get rid of the autofluorescence signal of tissues. PLNPs constitute a promising alternative to the commercially available optical near infrared probes thanks to their versatile functionalization capabilities for improvement of the circulation time in the blood stream.

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Developing tissues can self-organize into a variety of patterned structures through the stabilization of stochastic fluctuations in their molecular and cellular properties. While molecular factors and cell dynamics contributing to self-organization have been identified in vivo, events channeling self-organized systems such that they achieve stable pattern outcomes remain unknown. Here, we described natural variation in the fidelity of self-organized arrays formed by feather follicle precursors in bird embryos.

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