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CuIn crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Cu is bonded in a body-centered cubic geometry to two equivalent Cu and six equivalent In atoms. Both Cu–Cu bond lengths are 2.54 Å. All Cu–In bond lengths are 2.73 Å. In is bonded in a 6-coordinate geometry to six equivalent Cu atoms.
DyCu6In6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Dy is bonded in a 8-coordinate geometry to twelve Cu and eight In atoms. There are four shorter (3.52 Å) and eight longer (3.53 Å) Dy–Cu bond lengths. There are a spread of Dy–In bond distances ranging from 3.07–3.27 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to two equivalent Dy, four Cu, and six In atoms to form a mixture of distorted edge, face, and corner-sharing CuDy2In6Cu4 cuboctahedra. There are two shorter (2.69 Å) and two longer (2.79 Å) Cu–Cu bond lengths. There are a spread of Cu–In bond distances ranging from 2.74–2.81 Å. In the second Cu site, Cu is bonded in a 12-coordinate geometry to two equivalent Dy, four equivalent Cu, and six In atoms. There are a spread of Cu–In bond distances ranging from 2.74–2.93 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 8-coordinate geometry to one Dy, six Cu, and one In atom. The In–In bond length is 3.01 Å. In the second In site, In is bonded in a 10-coordinate geometry to one Dy and six Cu atoms. In the third In site, In is bonded in a 12-coordinate geometry to two equivalent Dy and six Cu atoms.
Sr(CuIn)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Sr is bonded in a 8-coordinate geometry to eight equivalent Cu and eight equivalent In atoms. All Sr–Cu bond lengths are 3.37 Å. All Sr–In bond lengths are 3.64 Å. Cu is bonded in a 9-coordinate geometry to four equivalent Sr, one Cu, and four equivalent In atoms. The Cu–Cu bond length is 2.50 Å. All Cu–In bond lengths are 2.75 Å. In is bonded to four equivalent Sr and four equivalent Cu atoms to form a mixture of distorted edge, face, and corner-sharing InSr4Cu4 tetrahedra.
Metal-organic frameworks (MOFs) are receiving increased attention due to their well-defined structures that allow the determination of structure-property relationships. MOFs have been used as heterogeneous catalyst supports in a variety of fashions including for confinement of metal nanoparticles, which have demonstrated enhanced resistance to aggregation, a common issue in amorphous metal oxide supports. Cu and In catalysts were installed in the Zr-based MOF NU-907, being confined within the nanoporous structure. The Cu catalyst is known to, under various conditions, either selectively hydrogenate acetylene to ethylene or generate C4 products such as butenes and 1,3-butadiene, an important feedstock for rubber and adhesives. The addition of indium to the Cu catalyst is intended to serve as a promoter to produce C4 products by decreasing the surface coverage of copper while still allowing for C-C coupling. When employed for acetylene dimerization, InCu-NU-907 shows slightly decreased C4 production overall but enhanced 1,3-butadiene production compared to all other catalysts studied herein. These catalysts were thoroughly characterized by a range of techniques to confirm structural integrity and porosity and probe the nature of the interactions of indium with the Cu nanoparticle active site.
The conformation of the human genome is known to play an important role in transcriptional control of gene expression. Our aim is to assess whether exposure of cultured human cardiomyocytes to hypergravity can induce changes in chromatin organization as assayed by Hi-C proximity ligation technique. Hi-C is used to analyze chromatin interactions by using formaldehyde to crosslink regions of chromatin that are in close proximity. The DNA is then fragmented using a restriction enzyme and ligated under dilute conditions to favor intramolecular ligation of cross-linked fragments. Finally, the DNA is sequenced, allowing reconstruction of genomic structure. iCell cardiomyocyte cultures will be exposed to 40 g via an engineered device (incu-fuge) that allows for the chemical fixation of cells on a spinning centrifuge. Additionally, we plan on using fluorescence microscopy to analyze the nuclear and actin cytoskeletal conformation of cardiomyocytes post hypergravity exposure. We hypothesize that chromatin will rearrange in hypergravity conditions, both rapidly due to direct mechanical forces, as well as over longer time frames due to changes to structures necessary for transcriptional responses such as the de novo formation of promoter-enhancer loops. A negative result–no change between 1 g and hypergravity conditions–would nevertheless be an important data point in our understanding of the rheology of the nucleus, and how cells and cellular structures respond to different gravity fields. The cellular physiology of hypergravity has clinical relevance for spaceflight, and can further inform our understanding of microgravity physiology.