Pandurowiese4158

Data are accessible via the ProteomeXchange server with the data set identifier PXD027310.The first examples of cross-metathesis between two different allenes is disclosed. First- and second-generation Ru complexes were found to be ineffective, at most affording only oligomeric products. The exception was a first-generation complex bearing a bidentate phenyl isopropoxy ligand (i.e., PCy3 is not released upon initiation), reactions with which afforded a 1,3-disubstituted allenyl boronate in 22% yield. On the basis of mechanistic studies designed to gain deeper understanding of the reasons for the ineffectiveness of different Ru catalysts, it was discovered that phosphine-free Ru-CAAC complexes have the steric and electronic attributes to be highly effective. The results of these investigations pave the way for development of additional olefin metathesis reactions that generate allenes.Halide perovskite heterocrystals, composed of distinct perovskite single crystals, have generated great interest for both fundamental research and applied device designs. One of the key advantages of using such a heterocrystal is its built-in electric potential, which enhances charge transport and suppresses the noise in the solid-state devices. On the basis of this strategy, high-performance optoelectronic devices (e.g., X-ray detectors) have been successfully demonstrated. However, the toxicity of metal cations (Pb) in those reported heterocrystals hinders their wider applications. Thus, developing lead-free halide perovskite heterocrystals is significant but remains highly challenging. Here, we report a solution-processed in situ heteroepitaxial approach that enables us to create the first lead-free halide perovskite heterocrystal, (BA)2CsAgBiBr7/Cs2AgBiBr6(BA = n-butylammonium), with dimensions of up to 10 × 7 × 6 mm3. The as-grown heterocrystals have high crystalline quality and present near atomically sharp interfaces. More excitingly, the (BA)2CsAgBiBr7/Cs2AgBiBr6 heterogeneous integration allows the formation of a built-in electric potential in the junction, which triggers spontaneous charge separation/transport. Consequently, X-ray detectors using the heterocrystals can operate in a self-driven mode and exhibit an impressive sensitivity (206 μC Gy-1 cm-2) superior to that of the pristine Cs2AgBiBr6 crystal detectors, an ultralow dark current, and operational stability. Our findings provide the first demonstration of lead-free halide perovskite heterocrystals and may open up opportunities for a host of sustainable and miniaturized perovskite optoelectronic devices.Nanopipettes are finding increasing use as nano "test tubes", with reactions triggered through application of an electrochemical potential between electrodes in the nanopipette and a bathing solution (bath). Key to this application is an understanding of how the applied potential induces mixing of the reagents from the nanopipette and the bath. Here, we demonstrate a laser scanning confocal microscope (LSCM) approach to tracking the ingress of dye into a nanopipette (20-50 nm diameter end opening). We examine the case of dianionic fluorescein under alkaline conditions (pH 11) and large applied tip potentials (±10 V), with respect to the bath, and surprisingly find that dye ingress from the bath into the nanopipette is not observed under either sign of potential. Finite element method (FEM) simulations indicate this is due to the dominance of electro-osmosis in mass transport, with electro-osmotic flow in the conventional direction at +10 V and electro-osmosis of the second kind acting in the same direction at -10 V, caused by the formation of significant space charge in the center of the orifice. The results highlight the significant deviation in mass transport behavior that emerges at the nanoscale and the utility of the combined LSCM and FEM approach in deepening understanding, which in turn should promote new applications of nanopipettes.The interface between two immiscible electrolyte solutions (ITIES) has become a very powerful analytical platform for sensing a diverse range of chemicals (e.g., metal ions and neurotransmitters) with the advantage of being able to detect non-redox electroactive species. The ITIES is formed between organic and aqueous phases. Organic solvent identity is crucial to the detection characteristics of the ITIES [half-wave transfer potential (E1/2), potential window range, limit of detection, transfer coefficient (α), standard heterogeneous ion-transfer rate constant (k0), etc.]. Here, we demonstrated, for the first time at the nanoscale, the detection characteristics of the NPOE/water ITIES. Linear detection of the diffusion-limited current at different concentrations of acetylcholine (ACh) was demonstrated with cyclic voltammetry (CV) and i-t amperometry. The E1/2 of ACh transfer at the NPOE/water nanoITIES was -0.342 ± 0.009 V versus the E1/2 of tetrabutylammonium (TBA+). The limit of detection of ACh at the NPOE/water nanoITIES was 37.1 ± 1.5 μM for an electrode with a radius of ∼127 nm. We also determined the ion-transfer kinetics parameters, α and k0, of TBA+ at the NPOE/water nanoITIES by fitting theoretical cyclic voltammograms to experimental voltammograms. This work lays the basis for future cellular studies using ACh detection at the nanoscale and for studies to detect other analytes. The NPOE/water ITIES offers a potential window distinct from that of the 1,2-dichloroethane (DCE)/water ITIES. This unique potential window would offer the ability to detect analytes that are not easily detected at the DCE/water ITIES.Bacteriophages (phages, bacteria-specific viruses) have biotechnological and therapeutic potential. To apply phages as pure or heterogeneous mixtures, it is essential to have a robust mechanism for transport and storage, with different phages having very different stability profiles across storage conditions. For many biologics, cryopreservation is employed for long-term storage and cryoprotectants are essential to mitigate cold-induced damage. Here, we report that poly(ethylene glycol) can be used to protect phages from cold damage, functioning at just 10 mg·mL-1 (∼1 wt %) and outperforms glycerol in many cases, which is a currently used cryoprotectant. Protection is afforded at both -20 and -80 °C, the two most common temperatures for frozen storage in laboratory settings. Crucially, the concentration of the polymer required leads to frozen solutions at -20 °C, unlike 50% glycerol (which results in liquid solutions). Post-thaw recoveries close to 100% plaque-forming units were achieved even after 2 weeks of storage with this method and kill assays against their bacterial host confirmed the lytic function of the phages. Initial experiments with other hydrophilic polymers also showed cryoprotection, but at this stage, the exact mechanism of this protection cannot be concluded but does show that water-soluble polymers offer an alternative tool for phage storage. Ice recrystallization inhibiting polymers (poly(vinyl alcohol)) were found to provide no additional protection, in contrast to their ability to protect proteins and microorganisms which are damaged by recrystallization. PEG's low cost, solubility, well-established low toxicity/immunogenicity, and that it is fit for human consumption at the concentrations used make it ideal to help translate new approaches for phage therapy.The current study reports an integrated approach of machine learning and tryptophan fluorescence and photoacoustic spectral properties to assess the mitochondrial status under oral pathological conditions. The mitochondria in the study were isolated from oral cancer tissues and adjacent normal counterparts, and the corresponding fluorescence and photoacoustic spectra of tryptophan were recorded at 281 nm pulsed laser excitations. A set of features were selected from the pre-processed spectra and were used to classify the data using support vector machine (SVM) learning in the MATLAB platform. SVM analysis demonstrated clear differentiation between mitochondria isolated from normal and cancer tissues for fluorescence (sensitivity, 86.6%; specificity, 90%) and photoacoustic (sensitivity, 86.6%; specificity, 96.6%) measurements. Further investigation into the influence of change in protein conformation on the nature of tryptophan spectral properties was evaluated by 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence assay. The impact of protein structural changes on the mitochondrial functions was also estimated by mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and cytochrome c oxidase (COX) assays, suggesting an altered mitochondrial function. The findings indicate that tryptophan fluorescence and photoacoustic spectral properties together with machine learning algorithms may delineate the mitochondrial functional status in vitro, indicating its translational potential.Small-molecular targeting peptides possess features of biocompatibility, affinity, and specificity, which is widely applied in molecular recognition and detection. Moreover, peptides can be developed into highly ordered supramolecular assemblies with boosting binding affinities, diverse functions, and enhanced stabilities suitable for biosensors construction. In this Review, we summarize recent progress of peptide-based biosensors for precise detection, especially on tumor-related analysis, as well as further provide a brief overview of the progress in tumor immune-related detection. Also, we are looking forward to the prospective future of peptide-based biosensors.Three disulfide bond-containing peptide amphiphiles (PA1-3) with different lengths of alkyl tails (PA1 for C6, PA2 for C12, and PA3 for C18) were synthesized by ring-opening polymerization of α-amino acid N-carboxyanhydride followed by post-polymerization modification. The peptide segments were composed of 3-mercaptopropionic acid-modified poly(l-cysteine) [P(Cys-SS-CH2CH2COOH)]. We characterized the chemical structure and molecular parameters by 1H NMR, 13C NMR, gel permeation chromatography, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy. It is found that alkyl-P(Cys-SS-CH2CH2COOH) mainly presents a β-sheet conformation at the solid state. However, the PAs present predominant random coils at pH 7.4 in aqueous solutions. The β-sheet conformation increased dramatically when the concentration of the PA exceeded its critical micelle concentration (ca. 0.3 mg/mL for PA3), indicating the formation of self-assembly-induced β-sheet nanostructures. Elongation of the alkyl chain length ontial for both systemic and localized delivery of therapeutics.Soy protein (SP) adhesives can resolve several problems with aldehyde-based adhesives, including formaldehyde release and excessive dependence on petroleum-based materials. Nevertheless, their development is hindered by the lack of balance between fluidity and high cold-pressing adhesive strength. A dynamically cross-linked SP adhesive with excellent fluidity and cold-pressing adhesion was developed in this study based on the polyphenol-metal ion redox-induced gelation system. SP was blended with acrylamide (AM), ammonium persulfate (APS), and the tannic acid (TA)-Fe3+ complex to prepare an adhesive gel precursor with good fluidity. In situ gelation of SP adhesive was then achieved via AM polymerization, as initiated by redox between TA and Fe3+. As expected, the prepared adhesive gel exhibited outstanding cold-pressing bonding strength (650 kPa) to the veneers compared to the neat SP adhesive, which has almost no cold-pressing bonding strength to the veneers. The TA-Fe3+ complex induced an in situ gelation system, which endowed the SP adhesive with strong cohesion; the topological entanglement of the adhesive gel in the veneers contributed to tight interfacial combinations.