9,108 research outputs found
PROBING CELLULAR MECHANO-SENSITIVITY USING BIOMEMBRANE-MIMICKING CELL SUBSTRATES OF ADJUSTABLE STIFFNESS
It is increasingly recognized that mechanical properties of substrates play a pivotal role in the regulation of cellular fate and function. However, the underlying mechanisms of cellular mechanosensing still remain a topic of open debate. Traditionally, advancements in this field have been made using polymeric substrates of adjustable stiffness with immobilized linkers. While such substrates are well suited to examine cell adhesion and migration in an extracellular matrix environment, they are limited in their ability to replicate the rich dynamics found at cell-cell interfaces. To address this challenge, we recently introduced a linker-functionalized polymer-tethered multi-bilayer stack, in which substrate stiffness can be altered by the degree of bilayer stacking, thus allowing the analysis of cellular mechanosensitivity. Here, we apply this novel biomembrane-mimicking cell substrate design to explore the mechanosensitivity of C2C12 myoblasts in the presence of cell-cell-mimicking N-cadherin linkers. Experiments are presented, which demonstrate a relationship between the degree of bilayer stacking and mechanoresponse of plated cells, such as morphology, cytoskeletal organization, cellular traction forces, and migration speed. Furthermore, we illustrate the dynamic assembly of bilayer-bound N-cadherin linkers underneath cellular adherens junctions. In addition, properties of individual and clustered N-cadherins are examined in the polymer-tethered bilayer system in the absence of plated cells
Plane-projection multi-photon microscopy for high-frame-rate Live Tissue Imaging
We present a wide-field multi-photon microscopy that provides optical sectioning at high frame rate under biocompatible laser dosage. Axial resolution comparable to confocal microscopy and 5-frame-per-second live tissue imaging are demonstrated
Top Quark Rare Decays via Loop-Induced FCNC Interactions in Extended Mirror Fermion Model
Flavor changing neutral current (FCNC) interactions for a top quark
decays into with represents a neutral gauge or Higgs boson, and a
up- or charm-quark are highly suppressed in the Standard Model (SM) due to the
Glashow-Iliopoulos-Miami mechanism. Whilst current limits on the branching
ratios of these processes have been established at the order of from
the Large Hadron Collider experiments, SM predictions are at least nine orders
of magnitude below. In this work, we study some of these FCNC processes in the
context of an extended mirror fermion model, originally proposed to implement
the electroweak scale seesaw mechanism for non-sterile right-handed neutrinos.
We show that one can probe the process for a wide range of parameter
space with branching ratios varying from to , comparable
with various new physics models including the general two Higgs doublet model
with or without flavor violations at tree level, minimal supersymmetric
standard model with or without -parity, and extra dimension model.Comment: 30 pages, 8 figures, 2 tables and 1 appendix. Version to appear in
NP
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