Generation of an induced pluripotent stem cell line (OGHFUi001-A) from a type 1 early infantile epileptic encephalopathy with ARX mutation.

Type 1 early infantile epileptic encephalopathy (EIEE1) is a severe early-onset epileptic encephalopathy with arrest of psychomotor development caused by hemizygous mutations in the ARX gene, which encodes a transcription factor in fundamental brain developmental processes. A human induced pluripotent stem cell (iPSC) line, termed as OGHFUi001-A, was generated using non-integrating episomal vector technique from peripheral blood mononuclear cells (PBMCs) of a 7-year-old male EIEE1 patient, who had a hemizygous (c.989G > T: p.R330L) mutation in the ARX gene. OGHFUi001-A offers a useful cell resource to investigate pathogenic mechanisms in EIEE1, as well as a cell-based model for drug development for EIEE1.

Geometry of the Contact Zone between Fused Membrane-Coated Beads Mimicking Cell-Cell Fusion.

The fusion of lipid membranes is a key process in biology. It enables cells and organelles to exchange molecules with their surroundings, which otherwise could not cross the membrane barrier. To study such complex processes we use simplified artificial model systems, i.e., an optical fusion assay based on membrane-coated glass spheres. We present a technique to analyze membrane-membrane interactions in a large ensemble of particles. Detailed information on the geometry of the fusion stalk of fully fused membranes is obtained by studying the diffusional lipid dynamics with fluorescence recovery after photobleaching experiments. A small contact zone is a strong obstruction for the particle exchange across the fusion spot. With the aid of computer simulations, fluorescence-recovery-after-photobleaching recovery times of both fused and single-membrane-coated beads allow us to estimate the size of the contact zones between two membrane-coated beads. Minimizing delamination and bending energy leads to minimal angles close to those geometrically allowed.

Optical fusion assay based on membrane-coated spheres in a 2D assembly.

A major goal in neurophysiology and research on enveloped viruses is to understand and control the biology and physics of membrane fusion and its inhibition as a function of lipid and protein composition. This poses an experimental challenge in the realization of fast and reliable assays that allow us, with a minimal use of fluorescent or radioactive labels, to identify the different stages of membrane-membrane interaction ranging from docking to complete membrane merging. Here, an optical two-dimensional fusion assay based on monodisperse membrane-coated microspheres is introduced, allowing unequivocal assignment of docking and membrane fusion. The hard-sphere fluid captures and quantifies relevant stages of membrane fusion and its inhibition without interference from aggregation, liposome rupture, extensive fluorescence labeling, and light scattering. The feasibility of the approach is demonstrated by using an established model system based on coiled-coil heterodimers formed between two opposing membrane-coated microspheres.

Alkyl chain length dependent morphology and emission properties of the organic micromaterials based on fluorinated quinacridone derivatives.

The fluorinated quinacridone derivatives N,N'-dialkyl-2,9-difluoroquinacridone (Cn-DFQA, n = 4, 8, 10, 16) with different alkyl chains were used as building blocks to assemble luminescent micromaterials. It was demonstrated that the morphology and emission of the Cn-DFQA-based micromaterials strongly depended on their alkyl chain length. C4-DFQA and C8-DFQA showed stronger tendency to form 1-D microstructures, while C10-DFQA and C16-DFQA displayed the aggregation properties to form diamond and hexagonal platelike microcrystals, respectively. The photoluminescent (PL) spectra of Cn-DFQA (n = 4, 8, 10, 16) in THF dilute solutions displayed approximate profiles with a sharp emission peak at 533 nm and a shoulder at 573 nm, while the PL spectra of the Cn-DFQA-based micromaterials exhibited obviously red-shift emission bands at 622 nm for C4-DFQA, 627 nm for C8-DFQA, 614 nm for C10-DFQA, and 613 nm for C16-DFQA, respectively. The single-crystal X-ray structures of four Cn-DFQA compounds have been studied. In the C4-DFQA and C8-DFQA single crystals, there are 1-D molecular columns based on the intermolecular pi...pi and hydrogen bonding interactions. In the single crystals of C10-DFQA and C16-DFQA, the molecules assembled into 2-D molecular sheets based on the hydrogen bonds and C-H...pi interactions. The molecular packing structures provide a reasonable explanation for the alkyl chain length dependent morphologies and emission properties of fluorinated quinacridone micromaterials.

Three-dimensional colloidal crystal-assisted lithography for two-dimensional patterned arrays.

In this paper, we report our recent work on preparing two-dimensional patterned microstructure arrays using three-dimensional colloidal crystals as templates, namely, colloidal crystal-assisted lithography. Two alternative processes are described and involved in colloidal crystal-assisted lithography. One is based upon imprinting the polymer films with three-dimensional silica colloidal crystals, and the other is based upon chemically depositing Ag microstructures on Au substrates covered by polymer colloidal crystals. By varying the experimental conditions in the colloidal crystal-assisted lithography process, we can intentionally control the morphologies of the resulting microstructures. The resultant Ag-coated Au substrates can be used as surface-enhanced Raman scattering substrates, and they would provide an ideal system for the mechanism study of surface-enhanced Raman scattering. We expect that colloidal crystal-assisted lithography will be a versatile approach which can be applied to patterning other materials such as functional molecules, polymers, oxides, and metals.