Tannermosley4918

Cu-based delafossites offer multifunctional properties that include electrical, magnetic, optical, and thermal transport, and they also act as a photocathode for energy-harvesting applications. Such properties can be modified by bringing about subtle changes in the chemical environment, like introducing holes or excess electrons in the system. With the aim to understand the evolution of physical properties that take place upon systematically replacing 3d3 (Cr3+) with 3d5 (Fe3+), we performed a comprehensive study of structural, electrical and thermal transport, and magnetic properties of the CuCr1-xFexO2 series. In agreement with the different ionic radii of trivalent cations, high-intensity X-ray diffraction confirms a systematic increase of the unit cell parameters. Extended X-ray absorption fine structure spectroscopy confirms the uniform solution of mixed trivalent Cr3+/Fe3+ cations and demonstrates the changes in the hybridization between Cu 3d and O 2p orbitals. Cu K-edge near-edge spectra reflect a shafluctuation and spin-phonon scattering taking place in these compositions.Targeting chemokine signaling is an attractive avenue for the treatment of inflammatory disorders. Tyrosine sulfation is an important post-translational modification (PTM) that enhances chemokine-receptor binding and is also utilized by a number of pathogenic organisms to improve binding affinity of immune-suppressive chemokine binding proteins (CKBPs). Here we report the display selection of tyrosine-sulfated cyclic peptides using a reprogrammed genetic code to discover high-affinity ligands for the chemokine CCL11 (eotaxin-1). The selected cyclic sulfopeptides possess high affinity for the target chemokine (as well as one or more of the related family members CCL2, CCL7 and CCL24) and inhibit CCL11 activation of CC chemokine receptor 3 (CCR3). This work demonstrates the utility in exploiting native PTMs as binding motifs for the generation of new leads for medicinal chemistry.In diagnostics of infectious diseases, MALDI-TOF mass spectrometry (MALDI-TOF MS) can be applied for the identification of pathogenic microorganisms. However, to achieve a trustworthy identification from MALDI-TOF MS data, a significant amount of biomass should be considered. The bacterial load that potentially occurs in a sample is therefore routinely amplified by culturing, which is a time-consuming procedure. In this paper we show that culturing can be avoided by conducting MALDI-TOF MS on individual bacterial cells. This results in a more rapid identification of species with an acceptable accuracy. We propose a deep learning architecture to analyze the data and compare its performance with traditional supervised machine learning algorithms. We illustrate our workflow on a large dataset that contains bacterial species related to urinary tract infections. Overall we obtain accuracies up to 85\% in discriminating five different species.A series of new tris(2-pyridyl) bismuthine ligands of the type [Bi(2-py')3] have been prepared, containing a range of substituents at various positions within their pyridyl rings (py'). They can act as intact ligands or, as a result of the low C-Bi bond energy, exhibit noninnocent reactivity in the presence of metal ions. Structural studies of Li+ and Ag+ complexes show that the coordination to metal ions using their pyridyl-N atoms and to anions using the Lewis acidity of their Bi(III) centers can be modified by the presence of substituents within the 2-pyridyl rings, especially at the 6- or 3-positions, which can block the donor-N or Lewis acid Bi sites. Electron withdrawing groups (like CF3 or Br) can also severely reduce their ability to act as ligands to metal ions by reducing the electron donating ability of the pyridyl-N atoms. Noninnocent character is found in the reactions with Cu+ and Cu2+, resulting in the coupling of pyridyl groups to form bipyridines, with the rate of this reaction being dependent on the anion present in the metal salts. This leads to the formation of Bi(III)/Cu(I) complexes containing hypervalent [X2Bi(2-R-py)]- (X = Cl, Br) anions. Alternatively, the tris(2-pyridyl) bismuthine ligands can act as 2-pyridyl transfer reagents, transferring 2-py groups to Au(I) and Fe(II).Benzophenone (BP) is an ultraviolet filter (UVF) widely used in personal care products such as sunscreens and cosmetics. Excessive exposure to BP-type UVFs is a potential threat to human's health because of their endocrine-disrupting activity. Water stability of lanthanide compounds is crucial when they serve as luminescent sensors because of the practicality and recyclability. In this study, a water-stable luminescent Zn-Tb heterometallic coordination polymer was rationally designed and synthesized for rapid detection of BP. Oxyphenisatin price This material showed a high quenching effect, excellent selectivity, and fast response toward BP.Despite broad interest in metal carbene complexes, there remain few examples of catalytic transformations of ethers that proceed via alkoxycarbene intermediates generated by α,α-dehydrogenation. We demonstrate that both neutral and cationic alkoxycarbene derivatives are accessible via ether dehydrogenation at a PNP(iPr)4 pincer-supported iridium complex (PNP(iPr)4 = 2,6-bis((diisopropylphosphino)methyl)pyridine). Both cationic and neutral alkoxycarbene complexes undergo group transfer imination with azides, with the cationic derivative serving as a more efficient catalyst for cyclopentyl ether imination. Mechanistic studies support an iridium(I)dinitrogen complex as the resting state in the dark and a role for light-promoted N2 dissociation. Isoamyl nitrite and phenyl ethyl ketene are also found to engage with the cationic alkoxycarbene complex in formal alkoxide and O atom transfer reactions, respectively. In the former case an isolable dialkoxyalkyliridium complex is obtained, representing only the second example of a structurally characterized dialkoxyalkyl complex of a transition metal.A novel family of five Mn-Te-CO complexes was prepared via facile syntheses mono spirocyclic [Mn4Te(CO)16]2- (1), four-membered Mn2Te2 ring-type [Mn2Te2(CO)8]2- (2), hydride-containing square pyramidal [HMn3Te2(CO)9]2- (3), and dumbbell-shaped [Mn6Te6(CO)18]4- (4) and [Mn6Te10(CO)18]4- (5). Electron-precise complexes 4 and 5 exhibit unusual paramagnetism arising from two types of Mn atoms in different oxidation states, as determined by X-ray photoelectron spectroscopy, electron paramagnetic resonance, and density functional theory (DFT) calculations. The structural transformations from small-sized Mn4Te 1 and Mn2Te2 2 to the largest Mn6Te10 5 were controllable, the off/on magnetic-switched transformation between HMn3Te2 3 and 5 was reversible, and the magnetic transformation between Mn6Te6 4 and 5 was observed. Interestingly, the reversible dehydridation and hydridation between the HMn3Te2-based cluster 3 and [Mn3Te2(CO)9]- were successfully accomplished, in which the release of a high yield of H2 was detected by gas chromatography. In addition, upon the addition of CO, cluster 3 first forms a carbonyl-inserted intermediate [HMn3Te2(CO)10]2- (3'), detected by the high resolution ESI-MS, which is readily transformed to a dimeric dihydrido cluster [HMn3Te2(CO)102]2- (6) with the introduction of O2. These low- to high-nuclearity complexes exhibit rich redox properties with semiconducting behavior in solids, possessing low but tunable energy gaps (1.06-1.62 eV) due to efficient electron transport via nonclassical C-H···O(carbonyl) interactions. The structural nature, reversible structural transformations, controllable on/off magnetic switches, electron communication networks, and associated chemical properties for hydrogen generation are discussed in detail and supported by DFT calculations, density of states, band structures, and noncovalent interaction analyses.Layered Black Phosphorus (BP) is a member of a layered material family with anisotropic properties and layer-dependent band gaps, and that can be exfoliated down to single-layered phosphorene. Compared with graphene, few-layered BP and its single-layer phosphorene are significantly more reactive and this reactivity can be applied for the autogenous reduction of gold ions to metallic gold nanoparticles supported by few-layered BP (Au/BP). Few-layered BP and gold are well known oxidation catalysts important in organic synthesis and also in the catalytic treatment and purification of industrial waste water. The treatment of organic contamination present in industrial waste water presents serious problems and is an important issue for current catalysis. Here, we show high catalytic activity of the gold supported on few-layered black phosphorus (Au/BP) for wet oxidation of acrylic acid, including samples of industrial waste water with complex composition. The catalyst Au/BP exhibits high stability, which allows utilization of its easily accessible 2D surface for the preparation of 2D material-supported metal catalysts.Transition metal sulfides (TMSs) have been demonstrated as attractive anodes for potassium-ion batteries (KIBs) due to the high capacity, abundant resource, and excellent redox reversibility. Unfortunately, practical implementation of TMSs to KIBs is still hindered by the unsatisfactory cyclability and rate performance which result from the vast volume variation during charge/discharge processes. Herein, a uniform nitrogen-doped carbon coated Cu2S hollow nanocube (Cu2S@NC) is designed as an anode material for the KIB, which displays an outstanding cycle performance (317 mAh g-1 after 1200 cycles at 1 A g-1) and excellent rate capacity (257 mAh g-1 at 6 A g-1) in a half-cell. The hollow nanosized structure can both shorten the diffusion length of potassium ions/electrons and buffer the volume expansion upon cycling. Besides, the high concentration electrolyte is beneficial to form the stable solid electrolyte interphase (SEI) film, reducing the interface impedance and enhancing the cycling stability. Ex situ transmission electron microscopy (TEM) and ex situ X-ray diffraction (XRD) reveal the reaction mechanism of Cu2S@NC.High-aspect-ratio nanostructures have emerged as versatile platforms for intracellular sensing and biomolecule delivery. Here, we present a microfabrication approach in which a combination of reactive ion etching protocols were used to produce high-aspect-ratio, nondegradable silicon nanoneedle arrays with tip diameters that could be finely tuned between 20 and 700 nm. We used these arrays to guide the long-term culture of human mesenchymal stem cells (hMSCs). Notably, we used changes in the nanoneedle tip diameter to control the morphology, nuclear size, and F-actin alignment of interfaced hMSCs and to regulate the expression of nuclear lamina genes, Yes-associated protein (YAP) target genes, and focal adhesion genes. These topography-driven changes were attributed to signaling by Rho-family GTPase pathways, differences in the effective stiffness of the nanoneedle arrays, and the degree of nuclear membrane impingement, with the latter clearly visualized using focused ion beam scanning electron microscopy (FIB-SEM). Our approach to design high-aspect-ratio nanostructures will be broadly applicable to design biomaterials and biomedical devices used for long-term cell stimulation and monitoring.