Abstract The existence of a 30‐nm fiber as basic folding unit for DNA packaging has remained topic active discussion. Here, we characterize the supramolecular structures formed by reversible Mg 2+ ‐dependent self‐association linear 12‐mer nucleosomal arrays using microscopy and physicochemical approaches. These reconstituted chromatin structures, which call “oligomers”, are globular throughout all stages cooperative assembly range in size from ~50 nm to maximum diameter ~1,000 nm. were...

Peristaltic crawling, which is the moving mechanism of earthworm-like limbless creatures in narrow spaces, a challenging target to mimic by using soft materials. Here we report an unprecedented hydrogel actuator that enables not only peristaltic crawling motion but also reversing its direction. Our cylindrically processed contains gold nanoparticles for photothermal conversion, thermoresponsive polymer network switching electrical permittivity gel interior, and cofacially oriented 2D...

Silk, which has excellent mechanical toughness and is lightweight, used as a structural material in nature, for example, silkworm cocoons spider draglines. However, the industrial use of silk garnered little attention. For to be material, its thermal processability associated properties must well understood. Although water molecules influence glass transition silk, effects content on other silks are not In this study, we prepared Bombyx mori cocoon raw fibers, degummed films with different...

Abstract Silk has attracted widespread attention due to its superlative material properties and promising applications. However, the determinants behind variations in among different types of silk are not well understood. We analysed physical samples from a variety silkmoth cocoons, including domesticated Bombyx mori varieties several species Saturniidae. Tensile deformation tests, thermal analyses investigations on crystalline structure orientation fibres were performed. The results showed...

How is a long strand of genomic DNA packaged into mitotic chromosome or nucleus? The nucleosome fiber (beads-on-a-string), in which wrapped around core histones, has been assumed to be folded 30-nm chromatin fiber, and further helically larger fiber. However, when frozen hydrated human cells were observed using cryoelectron microscopy, no higher-order structures that included fibers found. To investigate the bulk structure chromosomes further, we performed small-angle X-ray scattering...

Covalent organic synthesis commonly uses the strategy of selective bond cleavage and formation. If a similar approach can be applied stepwisely to noncovalent synthesis, more exotic or challenging nanostructures might become achievable. Here, we report that ferrocene-based tetratopic pyridyl ligands, which dynamically change their geometry by means thermal rotation cyclopentadienyl rings in solution, assemble with AgBF4 into discrete metal-organic nanotubes large uniform diameters. The cut...

Standing at order Thin films of organic molecules on solid substrates tend to nucleate many sites and grow multiple domains. However, one large uniform film would be much more desirable in device applications. Seiki et al. designed that filled space a hexagonal tiling; propeller-like triptycene base adhered crystalline surfaces alkyl tails extended away from it. The authors could make well-ordered multilayer up centimeter length scales. Science , this issue p. 1122

Abstract Fluids that contain ordered nanostructures with periodic distances in the visible-wavelength range, anomalously exhibit structural colours can be rapidly modulated by external stimuli. Indeed, some fish dynamically change colour modulating distance of crystalline guanine sheets cofacially oriented their fluid cytoplasm. Here we report a dilute aqueous colloidal dispersion negatively charged titanate nanosheets exhibits colours. In this ‘photonic water’, spontaneously adopt cofacial...

Mating disks and rods into an ordered phase Disk-shaped molecules tend to stack in columns, whereas rod-shaped ones align parallel each other. When the two types of are mixed, they separate. Yano et al. found right recipe that allowed enough affinity between so formed a blended twisted columnar phase. The could be stabilized by polymerizing disks. orientation columns altered using electric fields, optical stimuli lead second ordering transition. Science , this issue p. 161

Semiconducting colloidal quantum dots and their assemblies exhibit superior optical properties owing to the confinement effect. Thus, they are attracting tremendous interest from fundamental research commercial applications. However, electrical conducting remain detrimental predominantly due orientational disorder of in assembly. Here we report high conductivity consequent metallic behaviour semiconducting lead sulphide. Precise facet orientation control forming highly-ordered...

A micro-focused X-ray beam with size ranging from 1 × to 10 μm has been achieved at beamline BL32XU SPring-8, Japan. Combining the available micro-beam newly developed techniques enabled efficient protein micro-crystallography.

A homogeneous-nucleation-based crystallization was found in o-terphenyl the glass-transition temperature region with an adiabatic calorimeter, and process investigated by direct microscopic observation. The showed its maximum rate at 248 ceased 250 K, while ordinary crystal-growth observed to proceed only above 255 K. two crystals formed 297 K same x-ray-diffraction patterns, indicating that they were crystalline phase. nucleation-based range of 225 as advance crystal front into liquid phase...

As one of the most effective molecular design strategies in organic electronics, heteroatom substitution was employed for first time to study acceptor variation effects on optical, electrochemical, assembling, and charge-transport properties novel semiconducting polymers containing benzobisthiadiazole (BBT)-related heterocycles, namely, poly(dithiazolfluorene-alt-thiadiazolobenzotriazole) (PSN), poly(dithiazolfluorene-alt-selenadiazolobenzotriazole) (PSeN),...

Tailoring structurally anisotropic molecular assemblies while controlling their orientation on solid substrates is an important subject for advanced technologies that use organic thin films. Here we report a supramolecular scaffold based tripodal triptycene assemblies, which enables functional units to assemble into highly oriented, multilayered two-dimensional (2D) structure substrates. The building block carries ethynyl group and three flexible side chains at the 10- 1,8,13-positions,...

The spider silk spinning process converts spidroins from an aqueous form to a tough fiber. This has been investigated by numerous researchers, and micelles or liquid crystals of have reported fibers, which are bundles microfibrils. However, the formation microfibrils not clarified previously. Here, we report that generated through formation, homogenization, linkage crystalline granules without micelle-like structures. Heterogeneous on submicron micron scale were observed in storage sac,...

Abstract Peristaltic crawling, which is the moving mechanism of earthworm‐like limbless creatures in narrow spaces, a challenging target to mimic by using soft materials. Here we report an unprecedented hydrogel actuator that enables not only peristaltic crawling motion but also reversing its direction. Our cylindrically processed contains gold nanoparticles for photothermal conversion, thermoresponsive polymer network switching electrical permittivity gel interior, and cofacially oriented...

The assembly reaction of Escherichia coli ferritin A (EcFtnA) was studied using time-resolved small-angle X-ray scattering (TR-SAXS). EcFtnA forms a cagelike structure that consists 24 identical subunits and dissociates into dimers at acidic pH. dimer maintains nativelike secondary tertiary structures is able to reassemble 24-mer when the pH increased. reassembly induced by jump, followed TR-SAXS. Time-dependent changes in forward intensity gyration radius suggested existence significant...

An artificial spinning system using regenerated silk fibroin solutions is adopted to produce high-performance fibers. In previous studies, alcohol-based agents, such as methanol or ethanol, were used coagulate dope solutions, producing fiber with poor mechanical properties compared those of native The coagulation agents induce rapid β-sheet crystallization the molecules, which inhibits subsequent alignment crystals. Here, we gradual formation afford adequate similar that fiber. To this aim,...

Although various biomimetic soft materials that display structural hierarchies and stimuli responsiveness have been developed from organic materials, the creation of their counterparts consisting entirely inorganic presents an attractive challenge, as properties such generally differ those living organisms. Here, we a hydrogel nanosheets (14 wt%) water (86 undergoes thermally induced reversible abrupt changes in its internal structure mechanical elasticity (23-fold). At room temperature,...