Recently, flexible wearable electronic devices have attracted immense interest as an alternative for conventional rigid metallic conductors in personal healthcare monitoring, human motion detection, and sensory skins, owing to their intrinsic characteristics. However, the practical applications of most wearable sensors are generally limited by their poor stretchability and sensitivity, unsatisfactory strength, lower conductivity, and single sensory function. Here a hydrogen bond cross‐linked network based on carboxylic styrene butadiene rubber (XSBR) and hydrophilic sericin (SS) non‐covalently modified carbon nanotubes (CNTs) is rationally designed and then fabricated into multi‐functional sensors. The resultant versatile sensors are able to detect both weak and large deformations, which owns a low detection limit of 1% strain, high stretchability up to 217%, superior strength of 12.58 MPa, high sensitivity with a gauge factor up to 25.98, high conductivity of 0.071 S m−1, and lower percolation threshold of 0.504 wt%. Moreover, the prepared sensors also possess an impressively thermal response (0.01636 °C−1) and realize the application in the measurement of human body temperature. The multifunctional and scalable XSBR/SSCNT sensor with the integrated tracking capabilities of real‐time and in situ physiological signals, providing a promising route to develop wearable artificial intelligence in human health and sporting applications.

A series of new mixed-ligand copper(I) complexes [Cu(NN)-POP]BF 4 , where NN = 1,10-phenanthroline (phen; 1a), 2,9-dimethyl-phen (DMphen; 1b), 4,7-diphenyl-phen (DPpehn; 1c) and 2,2Ј-bipyridine (bpy; 2a), have been synthesized. Density functional theory (DFT) was applied to study the ground-and excited-state properties of these copper(I) complexes. The electronic structure variation is obtained by changing the substituted positions on the phenanthroline ligand. A time-dependent-DFT approach (TDDFT) was used to interpret the absorption and emission spectra in this system based on the optimized geometries at the B3LYP/ LANL2DZ and CIS/LANL2DZ levels of theory, respectively. The results show that the lowest-energy excitations of all

The competition between bimolecular nucleophilic substitution and base-induced elimination is of fundamental importance for the synthesis of pure samples in organic chemistry. Many factors that influence this competition have been identified over the years, but the underlying atomistic dynamics have remained difficult to observe. We present product velocity distributions for a series of reactive collisions of the type X− + RY with X and Y denoting the halogen atoms fluorine, chlorine and iodine. By increasing the size of the residue R from methyl to tert-butyl in several steps, we find that the dynamics drastically change from backward to dominant forward scattering of the leaving ion relative to the reactant RY velocity. This characteristic fingerprint is also confirmed by direct dynamics simulations for ethyl as residue and attributed to the dynamics of elimination reactions. This work opens the door to a detailed atomistic understanding of transformation reactions in even larger systems.

Utilizing a newly developed atomic-force-microscopy-based wide-frequency rheology system, we measured the dynamic nanomechanical behavior of normal and glycosaminoglycan (GAG)-depleted cartilage, the latter representing matrix degradation that occurs at the earliest stages of osteoarthritis. We observed unique variations in the frequency-dependent stiffness and hydraulic permeability of cartilage in the 1 Hz-to-10 kHz range, a frequency range that is relevant to joint motions from normal ambulation to high-frequency impact loading. Measurement in this frequency range is well beyond the capabilities of typical commercial atomic force microscopes. We showed that the dynamic modulus of cartilage undergoes a dramatic alteration after GAG loss, even with the collagen network still intact: whereas the magnitude of the dynamic modulus decreased two- to threefold at higher frequencies, the peak frequency of the phase angle of the modulus (representing fluid-solid frictional dissipation) increased 15-fold from 55 Hz in normal cartilage to 800 Hz after GAG depletion. These results, based on a fibril-reinforced poroelastic finite-element model, demonstrated that GAG loss caused a dramatic increase in cartilage hydraulic permeability (up to 25-fold), suggesting that early osteoarthritic cartilage is more vulnerable to higher loading rates than to the conventionally studied "loading magnitude". Thus, over the wide frequency range of joint motion during daily activities, hydraulic permeability appears the most sensitive marker of early tissue degradation.

Classical trajectory simulations are performed to study energy transfer in collisions of protonated diglycine, gly 2 -H + , and dialanine, ala 2 -H + , ions with a fluorinated octanethiol self-assembled monolayer (F-SAM) surface for collision energies E i in the range of 5-70 eV and incident angles θ i of 0 and 45°with respect to the surface normal. Both explicit-atom (EA) and united-atom (UA) models were used to represent the F-SAM surface. The simulations show the distribution of energy transfer to the peptide-ion's internal degrees of freedom, ∆E int , to the surface, ∆E surf , and in peptide-ion translation, E f , are very similar for gly 2 -H + , and ala 2 -H + . The average percentage energy transferred to ∆E surf and E f increases and decreases, respectively, with an increase in E i , while the average percentage energy transfer to ∆E int is nearly independent of E i . Changing θ i from 0 to 45°decreases and increases the percentage of energy transfer to ∆E surf and E f , respectively, but has little change in the transfer to ∆E int . Average percentage energy transfer to the surface is found to approximately depend on E i according to exp(-b/E i ). Comparisons with previous simulations show that peptide-H + collisions with the EA F-SAM model transfer approximately a factor of 2 more energy to ∆E int than do collisions with the hydrogenated SAM, that is, H-SAM. Replacing the mass of the F atoms by that of a H atom in the simulations, without changing the potential, shows that the different ∆E int energy transfer efficiencies for the F-SAM and H-SAM surfaces is a mass effect. The simulations for ala 2 -H + colliding with the EA F-SAM surface give P(∆E int ) distributions in good agreement with previous experiments and an average transfer to ∆E int of 15% as compared with the experimental value of 21%. The UA F-SAM model gives energy transfer efficiencies in qualitative agreement with those of the EA model, but there are important quantitative differences.

A UiO-66 core with various sizes acts as heterogeneous nucleation center and enables aniline polymerization under ambient conditions. The as-synthesized UiO-66@PAN possesses uniform size and excellent dispersibility in aqueous solution. UiO-66@PAN can be internalized by cancer cells via endocytosis, and indicates significant photothermal therapeutic effect in vitro, and can effectively inhibit the growth of colon cancers in vivo.

Competiting S2 substitution and E2 elimination reactions are of central importance in preparative organic synthesis. Here, we unravel how individual solvent molecules may affect underlying S2/E2 atomistic dynamics, which remains largely unclear with respective to their effects on reactivity. Results are presented for a prototype microsolvated case of fluoride anion reacting with ethyl bromide. Reaction dynamics simulations reproduce experimental findings at near thermal energies and show that the E2 mechanism dominates over S2 for solvent-free reaction. This is energetically quite unexpected and results from dynamical effects. Adding one solvating methanol molecule introduces strikingly distinct dynamical behaviors that largely promote the S2 reaction, a feature which attributes to a differential solute-solvent interaction at the central barrier that more strongly stabilizes the transition state for substitution. Upon further solvation, this enhanced stabilization of the S2 mechanism becomes more pronounced, concomitant with drastic suppression of the E2 route. This work highlights the interplay between energetics and dynamics in determining mechanistic selectivity and provides insight into the impact of solvent molecules on a general transition from elimination to substitution for chemical reactions proceeding from gas- to solution-phase environments.

Porphyrin-containing carbon dots (CDs) possess ultrasmall size, excellent water solubility, and photostability. These CDs can effectively generate cytotoxic singlet oxygen upon irradiation, and induce the cell apoptosis. Photodynamic ability of CDs inhibits the growth of hepatoma. This work not only sheds light on developing functional carbon dots, but also highlights the importance of special-structure precursor molecules in synthesizing functional CDs.