Light- and Temperature-Assisted Spin State Annealing: Accessing the Hidden Multistability

Among the responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here in a 2D Hofmann-type coordination polymer [Fe(isoq)₂{Au(CN)₂}₂] (isoq = isoquinoline), hidden multistability of the spin state is accessed by introducing an medium-temperature annealing after a light/temperature stimulation. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.

Light- and Temperature-Assisted Spin State Annealing: Accessing the Hidden Multistability

Among the responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here in a 2D Hofmann-type coordination polymer [Fe(isoq)₂{Au(CN)₂}₂] (isoq = isoquinoline), hidden multistability of the spin state is accessed by introducing an medium-temperature annealing after a light/temperature stimulation. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.

The effect of 10,12-pentacosadiynoic acid on the morphology and characteristics of electrospun PDA/PU nanofibers

In this study, the effect of 10,12-pentacosadiynoic acid (PCDA) on the fabrication of PDA/PU nanofibers was examined. The PDA/PU nanofibers were prepared by electrospinning PU and PCDA at different mixing ratios, followed by photopolymerization. The viscosity and conductivity of the spinning solution and the morphology of the fabricated nanofibers were analyzed. We also examined the chemical structure changes, physical structure changes, and color transition characteristics of PDA/PU nanofibers. The concentrations of the spinning solutions and the mixing ratio of PCDA and PU had significant effects on the viscosity of the spinning solution and the diameter and shape of the nanofibers. The optimum conditions for economic efficiency and the practicality of the fabrication of a PDA/PU nano-fibers were 12–14 wt% spinning solution and a ratio of PU to PCDA of 4 to 1 or greater. For these conditions, the viscosity was in the range of 225–290 cP, which resulted in the production of smooth, uniform PDA/PU nanofibers without beads. The diameters of the nanofibers ranged from 270 to 550 nm. The results of FT-IR, XRD and DSC analyses confirmed that the PCDA were well mixed with the PU molecules and were electrospun. The fabricated PDA/PU nanofibers exhibited color transition phenomenon by external temperature stimulation above 70 °C.

HESC-derived sensory neurons reveal an unexpected role for PIEZO2 in nociceptor mechanotransduction

Somatosensation, the detection and transduction of external and internal stimuli, has fascinated scientists for centuries. But still, some of the mechanisms how distinct stimuli are detected and transduced are not entirely understood. Over the past decade major progress has increased our understanding in areas such as mechanotransduction or sensory neuron classification. Additionally, the accessibility to human pluripotent stem cells and the possibility to generate and study human sensory neurons has enriched the somatosensory research field.Based on our previous work, the generation of functional human mechanoreceptors, we describe here the generation of hESC-derived nociceptor-like cells. We show that by varying the differentiation strategy, we can produce different nociceptive subpopulations. One protocol in particular allowed the generation of a sensory neuron population, homogeneously expressing TRPV1, a prototypical marker for nociceptors. Accordingly, we find the cells to homogenously respond to capsaicin, to become sensitized upon inflammatory stimuli, and to respond to temperature stimulation.Surprisingly, all of the generated subtypes show mechano-nociceptive characteristics and, quite unexpectedly, loss of mechanotransduction in the absence of PIEZO2.