Temporal evolution of mechanical properties in PDMS: A comparative study of elastic modulus and relaxation time for storage in air and aqueous environment.

Polydimethylsiloxane (PDMS) is a soft, biocompatible polymer extensively employed in biomedical research, notable for its tunable mechanical properties achieved through cross-linking. While many studies have assessed the mechanical properties of PDMS utilizing macroscopic and microscopic methods, these analyses are often limited to freshly prepared samples. However, the mechanical properties of PDMS can be expected to change during prolonged exposure to water or air, such as interface polymer chain loosening or surface hardening, which are critical considerations in applications like cell culture platforms or microfluidic devices.

Enhancing nanoscale viscoelasticity characterization in bimodal atomic force microscopy.

Polymeric, soft, and biological materials exhibit viscoelasticity, which is a time dependent mechanical response to deformation. Material viscoelasticity emerges from the movement of a material's constituent molecules at the nano- and microscale in response to applied deformation. Therefore, viscoelastic properties depend on the speed at which a material is deformed.

Tumor-immune metaphenotypes orchestrate an evolutionary bottleneck that promotes metabolic transformation.

Introduction: Metabolism plays a complex role in the evolution of cancerous tumors, including inducing a multifaceted effect on the immune system to aid immune escape. Immune escape is, by definition, a collective phenomenon by requiring the presence of two cell types interacting in close proximity: tumor and immune. The microenvironmental context of these interactions is influenced by the dynamic process of blood vessel growth and remodelling, creating heterogeneous patches of well-vascularized tumor or acidic niches.

Nanoscale Rheology: Dynamic Mechanical Analysis over a Broad and Continuous Frequency Range Using Photothermal Actuation Atomic Force Microscopy.

Polymeric materials are widely used in industries ranging from automotive to biomedical. Their mechanical properties play a crucial role in their application and function and arise from the nanoscale structures and interactions of their constitutive polymer molecules. Polymeric materials behave viscoelastically, i.

Necrosis and ethylene-inducing-like peptide patterns from crop pathogens induce differential responses within seven brassicaceous species.

Translational research is required to advance fundamental knowledge on plant immunity towards application in crop improvement. Recognition of microbe/pathogen-associated molecular patterns (MAMPs/PAMPs) triggers a first layer of immunity in plants. The broadly occurring family of necrosis- and ethylene-inducing peptide 1 (NEP1)-like proteins (NLPs) contains immunogenic peptide patterns that are recognized by a number of plant species.

Voltage-Driven Alterations to Neuron Viscoelasticity.

Background: The consideration of neurons as coupled mechanical-electrophysiological systems is supported by a growing body of experimental evidence, including observations that cell membranes mechanically deform during the propagation of an action potential. However, the short-term (seconds to minutes) influence of membrane voltage on the mechanical properties of a neuron at the single-cell level remains unknown.

Materials And Methods: Here, we use microscale dynamic mechanical analysis to demonstrate that changes in membrane potential induce changes in the mechanical properties of individual neurons.

A new tool for conditional gene manipulation in a subset of keratin-expressing epithelia.

Megsin is a serine protease inhibitor (Serpin) that has known expression in kidney mesangial cells. Here, we report the generation and characterization of a bacterial artificial chromosome (BAC) transgene expressing Cre under the control of Megsin regulatory elements. When crossed to the ROSA26R-lacZ reporter mice, the Megsin-Cre transgene mediates loxP recombination primarily in the skin, forestomach, and esophagus, but surprisingly not in the mesangial cells.

Absence of canonical Smad signaling in ureteral and bladder mesenchyme causes ureteropelvic junction obstruction.

Obstruction of the ureteropelvic junction (UPJ) is a common congenital anomaly frequently associated with ureteral defects. To study the molecular mechanisms that modulate ureteral development, we inactivated Smad4, the common Smad critical for transcriptional responses to TGF-β and Bmp signaling, in the ureteral and bladder mesenchyme during embryogenesis. Loss of canonical Smad signaling in these tissues caused bilateral UPJ obstruction and severe hydronephrosis beginning at embryonic day 17.