3,306 research outputs found
High-throughput intensity diffraction tomography with a computational microscope
We demonstrate a motion-free intensity diffraction tomography technique that enables direct inversion of 3D phase and absorption from intensity-only measurements for weakly scattering samples. We derive a novel linear forward model, featuring slice-wise phase and absorption transfer functions using angled illumination. This new framework facilitates flexible and efficient data acquisition, enabling arbitrary sampling of the illumination angles. The reconstruction algorithm performs 3D synthetic aperture using a robust, computation and memory efficient slice-wise deconvolution to achieve resolution up to the incoherent limit. We demonstrate our technique with thick biological samples having both sparse 3D structures and dense cell clusters. We further investigate the limitation of our technique when imaging strongly scattering samples. Imaging performance and the influence of multiple scattering is evaluated using a 3D sample consisting of stacked phase and absorption resolution targets. This computational microscopy system is directly built on a standard commercial microscope with a simple LED array source add-on, and promises broad applications by leveraging the ubiquitous microscopy platforms with minimal hardware modifications
2-[(2,6-Diethylphenyl)iminomethyl]-N-(2-methoxyphenyl)aniline
The title anilide–imine compound, C24H26N2O, features an intramolecular N—H⋯N hydrogen bond involving the imine and anilide groups to generate an S(6) ring motif. The molecule displays an E configuration about the imine C=N double bond, with the dihedral angle between the two benzene rings being 86.5°. The packing is stabilized by three different C—H⋯π interactions
Semaphorin 4D Promotes Skeletal Metastasis in Breast Cancer.
Bone density is controlled by interactions between osteoclasts, which resorb bone, and osteoblasts, which deposit it. The semaphorins and their receptors, the plexins, originally shown to function in the immune system and to provide chemotactic cues for axon guidance, are now known to play a role in this process as well. Emerging data have identified Semaphorin 4D (Sema4D) as a product of osteoclasts acting through its receptor Plexin-B1 on osteoblasts to inhibit their function, tipping the balance of bone homeostasis in favor of resorption. Breast cancers and other epithelial malignancies overexpress Sema4D, so we theorized that tumor cells could be exploiting this pathway to establish lytic skeletal metastases. Here, we use measurements of osteoblast and osteoclast differentiation and function in vitro and a mouse model of skeletal metastasis to demonstrate that both soluble Sema4D and protein produced by the breast cancer cell line MDA-MB-231 inhibits differentiation of MC3T3 cells, an osteoblast cell line, and their ability to form mineralized tissues, while Sema4D-mediated induction of IL-8 and LIX/CXCL5, the murine homologue of IL-8, increases osteoclast numbers and activity. We also observe a decrease in the number of bone metastases in mice injected with MDA-MB-231 cells when Sema4D is silenced by RNA interference. These results are significant because treatments directed at suppression of skeletal metastases in bone-homing malignancies usually work by arresting bone remodeling, potentially leading to skeletal fragility, a significant problem in patient management. Targeting Sema4D in these cancers would not affect bone remodeling and therefore could elicit an improved therapeutic result without the debilitating side effects
High-throughput intensity diffraction tomography with a computational microscope
We demonstrate a motion-free intensity diffraction tomography technique that
enables direct inversion of 3D phase and absorption from intensity-only
measurements for weakly scattering samples. We derive a novel linear forward
model, featuring slice-wise phase and absorption transfer functions using
angled illumination. This new framework facilitates flexible and efficient data
acquisition, enabling arbitrary sampling of the illumination angles. The
reconstruction algorithm performs 3D synthetic aperture using a robust,
computation and memory efficient slice-wise deconvolution to achieve resolution
up to the incoherent limit. We demonstrate our technique with thick biological
samples having both sparse 3D structures and dense cell clusters. We further
investigate the limitation of our technique when imaging strongly scattering
samples. Imaging performance and the influence of multiple scattering is
evaluated using a 3D sample consisting of stacked phase and absorption
resolution targets. This computational microscopy system is directly built on a
standard commercial microscope with a simple LED array source add-on, and
promises broad applications by leveraging the ubiquitous microscopy platforms
with minimal hardware modifications
- …