Ulrichcarter9547

By combining X-ray photoelectron spectroscopy and electrochemical characterization, we reveal the electron transfer between Pt, Pb, and Bi; this would lead to weakened CO adsorption and enhanced OH adsorption, thereby promoting the removal of toxic intermediates and ensuring that PtPbBi HNP samples have high activity and excellent stability. This work can inspire the design and synthesis of Pt-based nanocatalysts.Supramolecular materials have gained substantial interest for a number biological and nonbiological applications. However, for optimum utilization of these dynamic self-assembled materials, it is important to visualize and understand their structures at the nanoscale, in solution and in real time. Previous approaches for imaging these structures have utilized super-resolution optical imaging methods such as STORM, which has provided important insights, but suffers from drawbacks of complex sample preparation and slow acquisition times, thus limiting real-time in situ imaging of dynamic processes. We demonstrate a noncovalent fluorescent labeling design for STED-based super-resolution imaging of self-assembling peptides. This is achieved by in situ, electrostatic binding of anionic sulfonates of Alexa-488 dye to the cationic sites of lysine (or arginine) residues exposed on the peptide nanostructure surface. A direct, multiscale visualization of static structures reveals hierarchical organization of supramolecular fibers with sub-60 nm resolution. In addition, the degradation of nanofibers upon enzymatic hydrolysis of peptide could be directly imaged in real time, and although resolution was compromised in this dynamic process, it provided mechanistic insights into the enzymatic degradation process. Noncovalent Alexa-488 labeling and subsequent imaging of a range of cationic self-assembling peptides and peptide-functionalized gold nanoparticles demonstrated the versatility of the methodology for the imaging of cationic supramolecular structures. Overall, our approach presents a general and simple method for the electrostatic fluorescent labeling of cationic peptide nanostructures for nanoscale imaging under physiological conditions and probe dynamic processes in real time and in situ.Exploration of a new nonlinear optical (NLO)-active functional motif is important in the rational design of promising infrared (IR) NLO materials. Compared with typical tetrahedral MQ4 (M = IIB, III, IV metals; Q = S, Se) motifs, MQ3 (M = As, Sb) pyramids favor high second-harmonic generation (SHG) efficiency while frequently hindering phase matching (PM) because of excessively large optical anisotropy. The surfactant-thermal method was first adopted to achieve PM in MQ3-containing systems and synthesize mixed covalent-ionic IR NLO materials. Two new thioarsenates of AMnAs3S6 (A = Cs, Rb) exhibiting strong PM SHG efficiencies comparable to commercial AGS and laser-induced damage thresholds of one order higher than AGS were obtained. The [As3S6]3- unit in their structures is an unprecedented NLO-active functional motif, which can be useful in designing new IR NLO compounds with large SHG efficiency. In addition, the surfactant-thermal method provides a new general strategy for synthesizing new IR NLO materials.Designing nanoparticles (NPs) with desirable cell type-specific exocytosis properties, say promoting their exocytosis from scavenging cell types (e.g., macrophages and endothelial cells) or suppressing their exocytosis from target disease cell types (e.g., cancer cells), improves the application of nanomedicines. However, the design parameters available for tuning the exocytosis of NPs remain scarce in the "nano-cell" literature. Here, we demonstrate that surface modification of NPs with hydrocarbyl functional groups, commonly found in biomolecules and NP-based drug carriers, is a critical parameter for tuning the exocytosis of NPs from RAW264.7 macrophages, C166 endothelial cells, and HeLa epithelial cancer cells. To exclude the effect of hydrophobicity, we prepare a collection of hydrophilic NPs that bear a gold NP (AuNP) core, a dense polyethylene glycol (PEG) shell, and different types of hydrocarbyl groups (X) that are attached to the distal end of the PEG strands (termed "Au@PEG-X NPs"). For all three cell types tested, modification of NPs with straight-chain dodecane leads to a >10-fold increase in the level of cellular uptake, drastically higher than those of all other types of X tested. However, the probability of exocytosis of NPs significantly depends on the types of cell and X. Notably, NPs modified with cyclododecanes are most likely to be exocytosed by RAW264.7 and C166 cells (but not HeLa cells), accompanied by the release of intralumenal vesicles to the extracellular milieu. These data suggest a reductionist approach for rationally assembling bionanomaterials for nanomedicine applications by using hydrocarbyl functional groups as building blocks.Single-crystal perovskites with excellent photophysical properties are considered to be ideal materials for optoelectronic devices, such as lasers, light-emitting diodes and photodetectors. However, the growth of large-scale perovskite single-crystal films (SCFs) with high optical gain by vapor-phase epitaxy remains challenging. Herein, we demonstrated a facile method to fabricate large-scale thin CsPbBr3 SCFs (∼300 nm) on the c-plane sapphire substrate. High temperature is found to be the key parameter to control low reactant concentration and sufficient surface diffusion length for the growth of continuous CsPbBr3 SCFs. Through the comprehensive study of the carrier dynamics, we clarify that the trapped-related exciton recombination has the main effect under low carrier density, while the recombination of excitons and free carriers coexist until free carriers plays the dominate role with increasing carrier density. Furthermore, an extremely low-threshold (∼8 μJ cm-2) amplified spontaneous emission was achieved at room temperature due to the high optical gain up to 1255 cm-1 at a pump power of 20 times threshold (∼20 Pth). A microdisk array was prepared using a focused ion beam etching method, and a single-mode laser was achieved on a 3 μm diameter disk with the threshold of 1.6 μJ cm-2. Our experimental results not only present a versatile method to fabricate large-scale SCFs of CsPbBr3 but also supply an arena to boost the optoelectronic applications of CsPbBr3 with high performance.The introduction of dislocations is a recently proposed strategy to tailor the functional and especially the electrical properties of ceramics. While several works confirm a clear impact of dislocations on electrical conductivity, some studies raise concern in particular when expanding to dislocation arrangements beyond a geometrically tractable bicrystal interface. Moreover, the lack of a complete classification on pertinent dislocation characteristics complicates a systematic discussion and hampers the design of dislocation-modified electrical conductivity. We proceed by mechanically introducing dislocations with three different mesoscopic structures into the model material single-crystal SrTiO3 and extensively characterizing them from both a mechanical as well as an electrical perspective. As a final result, a deconvolution of mesoscopic structure, core structure, and space charge enables us to obtain the complete picture of the effect of dislocations on functional properties, focusing here on electric properties.Renewable bio-based electromagnetic interference (EMI) shielding materials receive increasing attention undoubtedly. However, there is still a challenge to use raw biomass materials to construct a significant structure through an effortless and environmental route for EMI shielding applications. Herein, for the first time, we demonstrated a hybrid composite of multi-walled carbon nanotube/polypyrrole/chrome-tanned collagen fiber (MWCNT/PPy/CF), which utilized waste chrome shavings as a matrix. X-ray photoelectron spectroscopy reveals that the chromium on the CF has a binding effect on the PPy layer, which endows the tight integration between the CF and PPy layer. selleck After the MWCNT network was loaded on the PPy layer, this ternary structure could provide stable conductive paths and a rich number of polarized interfaces. The MWCNT/PPy/CF composite exhibits superior electrical conductivity (354 ± 52 S/m), higher than PPy/CF (222 ± 38 S/m) and MWCNT/CF (104 ± 11 S/m), owing to the synergy of dual conductive structures. Notably, the shielding effectiveness (SE) value of the MWCNT/PPy/CF composite reaches 30 dB in the X band at a thickness of 0.48 mm. The shielding effectiveness of reflection (SER) (9.1 dB) is similar to that of PPy/CF (8.2 dB), while the shielding effectiveness of absorption (SEA) is significantly improved from 15.3 dB (PPy/CF) to 20.4 dB (MWCNT/PPy/CF) due to the additional coverage of the MWCNT network. link2 This indicates the synergy between the MWCNT network and conductive PPy/CF skeleton. This work provided a method to prepare sustainable and low-cost renewable EMI shielding materials using chrome shavings. Meanwhile, this novel structure combining a conductive skeleton and heterostructure can be considered as a potential application in relevant fields.We present a modular platform from which biohybrid protein-polymer nanostructures can be generated in a straightforward and facile manner. Specifically, an aqueous polymerization-induced self-assembly (PISA) AB block copolymerization system was derived from a mutant superfolder green fluorescent protein (sfGFP) as the solvophilic, stabilizing A block. By genetically encoding sfGFP with an isobutyryl bromide functionality, we grafted a quintessential atom-transfer radical polymerization initiation site with hydroxypropyl methacrylate (HPMA) to form the solvophobic B block. Monitoring nanostructure formation using dynamic light scattering, gel permeation chromatography, and transmission electron microscopy revealed uniform micellar morphologies. link3 The radii of the micelles increased with increasing HPMA block length, resulting in nanoparticle sizes ranging from 15 to 48 nm. Solvophilic stabilization afforded by the encoded sfGFP makes this an ideal PISA initiator, and we posit this platform has potential for generating complex biohybrid nanostructures for other protein-polymer systems.The metal nodes, functionalized ligands, and uniform channels of metal-organic frameworks (MOFs) are typically utilized to regulate the catalytic properties of metal nanoparticles (MNPs). However, though the ligand functionalization could impact the properties of the metal nodes and channels, which might further regulate the catalytic activity and selectivity of MNPs, related research in the design of MNP/MOF catalysts was usually neglected. Herein, we synthesized a series of Pt@UiO-66 composites (Pt@UiO-66-NH2, Pt@UiO-66-SO3H, and Pt@UiO-66) with slightly different organic ligands, which enhanced steric hindrance and contributed to multipathway electron transfer in selective hydrogenation of linear citronellal. The selectivity toward citronellol was gradually improved along with the increased size of functional groups (hydrogen, amino groups, and sulfo groups) on organic ligands, which enhanced steric hindrance provided by channels. In addition, the X-ray photoelectron spectroscopy measurements also revealed that the electronic state of Pt NPs was regulated through multipathway electron transfer from Pt NPs to metal nodes, between organic ligands and Pt NPs/metal nodes.