3D Printable One-Part Carbon Nanotube-Elastomer Ink for Health Monitoring Applications

3D printing of conductive elastomers is a promising route to personalized health monitoring applications due to its flexibility and biocompatibility. Here, a one-part, highly conductive, flexible, stretchable, 3D printable carbon nanotube (CNT)-silicone composite is developed and thoroughly characterized. The one-part nature of the inks: i) enables printing without prior mixing and cures under ambient conditions; ii) allows direct dispensing at ≈100 µm resolution printability on nonpolar and polar substrates; iii) forms both self-supporting and high-aspect-ratio structures, key aspects in additive biomanufacturing that eliminate the need for sacrificial layers; and iv) lends efficient, reproducible, and highly sensitive responses to various tensile and compressive stimuli. The high electrical and thermal conductivity of the CNT-silicone composite is further extended to facilitate use as a flexible and stretchable heating element, with applications in body temperature regulation, water distillation, and dual temperature sensing and Joule heating. Overall, the facile fabrication of this composite points to excellent synergy with direct ink writing and can be used to prepare patient-specific wearable electronics for motion detection and cardiac and respiratory monitoring devices and toward advanced personal health tracking and bionic skin applications.     

Syntheses of polyurethanes derived from oximes and their photodegradation

Polyoxime-urethanes have been synthesized from dioximes and diisocyanates, and their structures have been ascertained by elemental analysis and infrared spectroscopy. They can be represented by the general formula: These polymer films were photolyzed by using a high-pressure 100-W mercury lamp, and the rate of decomposition of the N? O bond was determined by use of ultraviolet and infrared spectra, or comparing the photochemical behavior with that of corresponding model compounds. Upon irradiating these polymers in the presence or absence of sensitizers or a hydrogen donor, there were obtained photolyzed polymers of low molecular weight, of which the molecular weights were estimated by observing the viscosity changes. To deduce the mechanism of photodegradation of polyoxime-urethane, photolysis of benzophenone oxime-phenyl urethane was investigated as a model compound.     

The molecular structure of norbornene as determined by electron diffraction and microwave spectroscopy

The molecular structure of norbornene has been investigated in the gas phase by combining electron diffraction data with microwave spectroscopic rotational constants. The interatomic distances (r_g) and bond angles were obtained by applying a least squares program to the refined experimental molecular diffraction intensities. The CC bond length was found to be 1.336 ± 0.002 Å while the

) bond length was 1. 529 ± 0.007 Å. Other bond lengths and angles included (IUPAC numbering system was used for norbornene): C₁-C₆ = 1.550 ± 0.020 Å, C₁-C₇ = 1.566± 0.005 Å, C₅-C₆ = 1.556 ± 0.005 Å, C-H_ave. = 1.103 ± 0.003 Å, ∠C₁C₂C₄ = 95.3°. The dihedral angle between planes C₁C₂C₃C₄ and C₁C₆C₅C₄ is 110.8 ± 1.5° while that between C₁C₂C₃C₄ and C₁C₇C₄ is 122.3°. The moments of inertia calculated from ED structure are in good agreement with microwave spectroscopic values.     

The Structure of the Antibiotic Hedamycin. I. Chemical,Physical and Spectral Properties

Interpretation of the chemical and spectral (IR., UV., ¹H- and ¹³C-NMR.) properties of the antitumor antibiotic hedamycin (C₄₁H₅₀N₂O₁₁) suggests that the molecule contains a methyl substituted 1-hydroxyanthraquinone nucleus, an α, β-unsaturated ketone, two sugar-like tetrahydropyran rings ( 4 and 8 ) and an aliphatic chain 2 , presumably with an epoxy group (see the Scheme).     

DNA-templated self-assembly of protein and nanoparticle linear arrays

Self-assembling DNA tiling lattices represent a versatile system for nanoscale construction. Self-assembled DNA arrays provide an excellent template for spatially positioning other molecules with increased relative precision and programmability. Here we report an experiment using a linear array of DNA triple crossover tiles to controllably template the self-assembly of single-layer or double-layer linear arrays of streptavidin molecules and streptavidin-conjugated nanogold particles through biotin-streptavidin interaction. The organization of streptavidin and its conjugated gold nanoparticles into periodic arrays was visualized by atomic force microscopy and scanning electron microscopy.