Edmondsonkessler3049

Thus, this first principles analysis provides clear indications to guide the interpretation of experimental studies, which cannot be obtained from simple Hückel model calculations.We report herein three air, thermal and solvent stable interlocked triacontanuclear giant nanocages, generated using a node and spacer concept. Interestingly, the crystal structures of the cages are not only nano-dimensional but also exist in the nano-dimension range, which was corroborated with microscopic images. The combination of microscopic and crystallographic data, in effect, led us to a unique advantageous situation of generating nanomaterials with hard-to-come-by structural information at the molecular level.Hollow prism-like NiCo2S4 materials (NiCo2S4 HNPs) were successfully fabricated by a two-step method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and powder X-ray diffraction (XRD) confirmed the morphology and structure of the as-prepared NiCo2S4 nanoprisms. A non-enzymatic sensor based on NiCo2S4 HNPs was constructed with outstanding electrochemical activity towards glucose oxidation in alkaline medium. The sensor showed a rapid response time (∼0.1 s), a high sensitivity of 82.9 μA mM-1 cm-2, a wide linear range (0.005-20.2 mM) and a detection limit of 0.8 μM (S/N = 3) with a good selectivity and reproducibility. Additionally, the proposed electrode also confirmed the feasibility in practical blood serum. These results indicate that NiCo2S4/ITO has great potential in the development of non-enzymatic glucose sensor applications.Tandem reactions of the yttrium(iii) catalyzed ring-opening reaction of 2,2'-diester aziridines with 3-(2-isocyanoethyl)indoles and the subsequent Friedel-Crafts/Mannich/desulfonylation were reported. A series of polycyclic spiroindolines containing tetrahydro-β-carbolines were obtained in moderate to excellent yields (56-92%) in one step under mild reaction conditions. A possible catalytic mechanism was also proposed.The replacement of noble metals with alternative electrocatalysts is highly demanded for water splitting. From the exploration of 3D -transition metal based heterostructures, engineering at the nano-level brought more enhancements in active sites with reduced overpotentials for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, recent developments in 3D transition metal based heterostructures like direct growth on external substrates (Ni foam, Cu foam) gave highly impressive activities and stabilities. Research needs to be focused on how the active sites can be enhanced further with 3D heterostructures of transition metals by studying them with various counterparts like hydroxides, layered double hydroxides and phosphides for empowering both OER and HER applications. This perspective covers the way to enlarge the utilization of 3D heterostructures successfully in terms of reduced overpotentials, highly exposed active sites, increased electrical conductivity, porosity and high-rate activity. From the various approaches of growth of transition metal based 3D heterostructures, it is easy to fine tune the active sites to have a viable production of hydrogen with less applied energy input. Overall, this perspective outlines a direction to increase the number of active sites on 3D transition metal based heterostructures by growing on 3D foams for enhanced water splitting applications.As an efflux pump, P-glycoproteins (P-gps) are over-expressed in many cancer cell types to confer them with multi-drug resistance. Many studies have focused on elucidating their molecular structure or protein expression; however, the relationship between the molecular assembly and dysfunction remains unclear. Super-resolution microscope is an excellent imaging tool to reveal the molecular biological details, but its high-quality imaging often suffers from the labeling method currently available. click here In this work, by exploiting its specificity and small size, tariquidar (specific inhibitor of P-gp) was modified by TAMRA to form a small chemical probe of P-gp. By direct stochastic optical reconstruction microscopic (dSTORM) imaging, tariquidar-TAMRA was first revealed to possess a higher labeling superiority and high binding specificity. Then, with the application of tariquidar-TAMRA labeling, we found that P-gps accumulate into larger and denser clusters on cancer cells and drug-resistant cells than on normal cells and drug-sensitive cells, indicating that P-gps can facilitate the pumping efficiency by aggregating together to form functional platforms. Moreover, these specific distribution patterns might serve as potential biomarkers for tumor and drug therapy screening.Inherently chiral calix[4]arenes with C4-symmetry are extremely rare and difficult to synthesise, severely hampering any effort to expand on their potential as chiral supramolecular catalysts and building blocks. Herein we report a reaction of a tetracarbamate calix[4]arene with NBS which results in a high yield of an inherently chiral calix[4]arenes with C4-symmetry. Furthermore, employing a chiral N-Boc proline moiety allows for separation of the diastereomers formed, thus obtaining the pure enantiomers after hydrolysis. The enantiomers could be assigned based on the CD spectra and DFT calculated values.Seven doubly 13C-labeled isotopomers of methyl β-D-glucopyranoside, methyl β-D-xylopyranoside, methyl β-D-galactopyranoside, methyl β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside and methyl β-D-galactopyranosyl-(1→4)-β-D-xylopyranoside were prepared, crystallized, and studied by single-crystal X-ray crystallography and solid-state 13C NMR spectroscopy to determine experimentally the dependence of 2JC1,C3 values in aldopyranosyl rings on the C1-C2-O2-H torsion angle, θ2, involving the C2 carbon of the C1-C2-C3 coupling pathway. Using X-ray crystal structures to determine θ2 in crystalline samples and by selecting compounds that exhibit a relatively wide range of θ2 values in the crystalline state, 2JC1,C3 values measured in crystalline samples were plotted against θ2 and the resulting plot compared to that obtained from density functional theory (DFT) calculations. For θ2 values ranging from ∼90° to ∼240°, very good agreement was observed between the experimental and theoretical plots, providing strong validation of DFT-calculated spin-coupling dependencies on exocyclic C-O bond conformation involving the central carbon of geminal C-C-C coupling pathways. These findings provide new experimental evidence supporting the use of 2JCCC values as non-conventional spin-coupling constraints in MA'AT conformational modeling of saccharides in solution, and the use of NMR spin-couplings not involving coupled hydroxyl hydrogens as indirect probes of C-O bond conformation. Solvomorphism was observed in crystalline βGal-(1→4)-βGlcOCH3 wherein the previously-reported methanol solvate form was found to spontaneously convert to a monohydrate upon air-drying, leading to small but discernible conformational changes in, and a new crystalline form of, this disaccharide.The rapid proliferation of tumor cells and tortuous vasculature in solid tumors often bring about a hypoxic tumor microenvironment, which renders tumor cells more resistant to many cancer treatments, including radiotherapy. In this study, an injectable and thermosensitive composite hydrogel composed of perfluorooctanoic acid (PFOA) modified monomethoxy poly(ethylene glycol)-poly(D,L-lactide-co-glycolide) (mPEG-PLGA-PFOA) and perfluorooctyl bromide (PFOB) that presented a thermoreversible sol-gel transition upon heating was developed to deliver exogenous oxygen for the relief of tumor hypoxia and enhancement of radiotherapy. The fluorinated modification of copolymers significantly increased the stability of PFOB in the mPEG-PLGA-PFOA aqueous solution owing to the fluorophilic interaction between PFOB and PFOA-modified copolymers. The introduction of PFOB not only efficiently heightened the oxygen loading capacity of the composite hydrogel, but also endowed it with excellent X-ray opacity, allowing the visual observation of the hydrogel via micro-CT imaging. After peritumoral injection of the oxygen-enriched composite hydrogel, the continuous supply of oxygen effectively relieved tumor hypoxia and down-regulated the expression of hypoxia-inducible factor-1α. Profiting from this, the hyposensitivity of tumor cells to radiation was successfully reversed, and the tumor growth in mice was significantly suppressed and the survival of mice was prolonged when combined with multiple X-ray exposure. As a result, the oxygen-enriched composite hydrogel shows a great potential for radiosensitization to improve the radiotherapeutic efficacy.A hetero-tetranuclear CeNi3 complex with a macrocyclic ligand catalysed the aerobic oxygenation of a methylene group adjacent to a carbonyl group under visible-light radiation to produce the corresponding α-diketones. The visible-light induced homolysis of the Ce-O bond of a bis(enolate) intermediate is proposed prior to aerobic oxygenation.Wound healing involves a complex series of events where cell-cell and cell-extracellular matrix (ECM) interactions play a key role. Wounding can be simple, such as the loss of the epithelial integrity, or deeper and more complex, reaching to subcutaneous tissues, including blood vessels, muscles and nerves. Rapid neovascularisation of the wounded area is crucial for wound healing as it has a key role in supplying oxygen and nutrients during the highly demanding proliferative phase and transmigration of inflammatory cells to the wound area. One approach to circumvent delayed neovascularisation is the exogenous use of pro-angiogenic factors, which is expensive, highly dose-dependent, and the delivery of them requires a very well-controlled system to avoid leaky, highly permeable and haemorrhagic blood vessel formation. In this study, we decorated polycaprolactone (PCL)-based polymerised high internal phase emulsion (PolyHIPE) scaffolds with fibroblast-derived ECM to assess fibroblast, endothelial cell and keratinocyte activity in vitro and angiogenesis in ex ovo chick chorioallantoic membrane (CAM) assays. Our results showed that the inclusion of ECM in the scaffolds increased the metabolic activity of three types of cells that play a key role in wound healing and stimulated angiogenesis in ex ovo CAM assays over 7 days. Herein, we demonstrated that fibroblast-ECM functionalised PCL PolyHIPE scaffolds appear to have great potential to be used as an active wound dressing to promote angiogenesis and wound healing.Although the general Lorenz-Mie formalism for spheres in an absorbing host has been developed, no correct analytical expressions in the small-particle limit have been published so far. Here, we derive two sets of analytical expressions for the extinction, absorption, and far- and near-field scattering cross sections of small particles embedded in an absorbing host. One set is a modification of the electrostatic approximation (EA) for an absorbing host, whereas the other represents an improved electrostatic approximation (IEA) based on the generalized Lorenz-Mie theory and a new form of Mie coefficients for the internal field expansion. To illustrate the accuracy of the derived approximations, we consider Au and Ag nanospheres embedded in model hosts (real part of the refractive index, 1.33; imaginary part, 0-0.3), in a lossless poly(methyl methacrylate) (PMMA), and a lossy poly(3-hexylthiophene) (P3HT) matrix. In general, the IEA cross sections agree with those calculated using Lorenz-Mie theory if the particle diameter is not greater than 50 nm.