Wheelerrafferty3195

From these results, it is suggested that the regioselective condensation reaction of the catechin B-ring is related to interactions between the A-rings, as indicated by earlier studies, and the presence of oxygen at the 1-position of the C-ring in EGC.To help address efficient separation of C2H n light hydrocarbons and C2H2/CO2 in the chemical industry, the self-assembly via an azolate-carboxylate ligand and Co(II) ion gave rise to a new porous MOF material, [Co(btzip)(H2btzip)]·2DMF·2H2O (1) (H2btzip = 4,6-bis(triazol-1-yl)isophthalic acid). In the MOF, the pores are modified by rich uncoordinated triazolyl Lewis basic N atoms and acidic -COOH groups, which strengthen interactions with C2H n hydrocarbons and CO2 molecules, leading to high adsorption amounts for C2H2, C2H4, C2H6, and CO2 and remarkable separation efficiency for C2H n -CH4, CO2-CH4, and C2H2-CO2 mixtures, as confirmed by breakthrough experiments on the realistic gas mixtures. The MOF also reveals outstanding selective adsorption ability for benzene/toluene, methanol/1-propanol, methanol/2-propanol, and 2-propanol/1-propanol isomers. Molecular simulations disclose the different adsorption sites in the MOF for various adsorbates.Proton transfer (PT) in an interaction system of a hydroxyl-amino group (OH-NH) plays a crucial role in photoinduced DNA and enzyme damage. A phenol-ammonia cluster is a prototype of an OH-NH interaction and is sometimes used as a DNA model. In the present study, the reaction dynamics of phenol-ammonia cluster cations, [PhOH-(NH3) n ]+ (n = 1-5), following ionization of the neutral parent clusters, were investigated using a direct ab initio molecular dynamics (AIMD) method. In all clusters, PTs from PhOH+ to (NH3) n were found postionization, the reaction of which is expressed as PhOH+-(NH3) n → PhO-H+(NH3) n . The time of the PT was calculated as 43 (n = 1), 26 (n = 2), and 13 fs (n = 3-5), suggesting that the rate of PT increases with an increase in n and is saturated at n = 3-5. The difference in the PT rate originates strongly from the proton affinity of the (NH3) n cluster. In the case of n = 3-5, a second PT was found, the reaction of which is expressed as PhO-H+(NH3) n → PhO-NH3-H+(NH3)n-1, and a third PT occurred at n = 4 and 5. The time of the PT was calculated as 10-13 (first PT), 80-100 (second PT), and 150-200 fs (third PT) in the case of larger clusters (n = 4 and 5). The reaction mechanism based on the theoretical results is discussed herein.Preventing the escape of hazardous genes from genetically modified organisms (GMOs) into the environment is one of the most important issues in biotechnology research. Various strategies were developed to create "genetic firewalls" that prevent the leakage of GMOs; however, they were not specially designed to prevent the escape of genes. To address this issue, we developed amino acid (AA)-swapped genetic codes orthogonal to the standard genetic code, namely SL (Ser and Leu were swapped) and SLA genetic codes (Ser, Leu, and Ala were swapped). From mRNAs encoded by the AA-swapped genetic codes, functional proteins were only synthesized in translation systems featuring the corresponding genetic codes. These results clearly demonstrated the orthogonality of the AA-swapped genetic codes against the standard genetic code and their potential to function as "genetic firewalls for genes". Furthermore, we propose "a codon-bypass strategy" to develop a GMO with an AA-swapped genetic code.We demonstrate the assembly of a compact, gel-like Langmuir-Blodgett film of rods formed by self-assembly of a β-sheet-forming water-soluble peptide, Ac-IKHLSVN-NH2, at the surface of aqueous electrolytes. We characterize surface pressure hysteresis and demonstrate shear stiffening of the surface caused by area cycling, which we interpret as due to rearrangement and alignment of the rods. We show strong effects of the electrolyte on the assembly of the elementary rods, which can be related to the Hofmeister series and interpreted by effects on the interaction energies mediated by ions and water. Formation of β-sheet structures and assembly of these into surface-segregated semicrystalline gels was strongly promoted by ammonium sulfate electrolyte. With ammonium sulfate electrolyte as subphase for Langmuir-Blodgett film deposition, shear stiffening by surface area cycling resulted in very compact films on transfer to a substrate.Fragrance emulsions are used in many applications in daily life. Since a lot of fragrances are quite volatile substances, their release rate from emulsions is a crucial factor. Since in most cases a mixture of fragrances is applied, the olfactory impression might change over time if the release rates of individual components differ significantly. For such applications, encapsulation with barrier materials is sought to retard release in an unselective manner. Stable fragrance-in-water emulsions were made by applying a synthetic hectorite as Pickering emulsifier which was fixed as a multilayer stack at the oil-water interface by adding poly(ethylene imine). The release of different fragrance molecules (eucalyptol, limonene, α-pinene, and ethyl-2-methylbutyrate) from these emulsions was studied as the ratio between hectorite and poly(ethylene imine) was varied. While the release rates of all fragrances were retarded by the hybrid capsule acting as a nonselective barrier, the relative release was determined by the solubility of individual fragrances in the capsule material. Fragrance release could be further reduced by additional chemical cross-linking of poly(ethylene imine).GHSR controls, among others, growth hormone and insulin secretion, adiposity, feeding, and glucose metabolism. Therefore, an inverse agonist ligand capable of selectively targeting GHSR and reducing its high constitutive activity appears to be a good candidate for the treatment of obesity-related metabolic diseases. In this context, we present a study that led to the development of several highly potent and selective inverse agonists of GHSR based on the 1,2,4-triazole scaffold. We demonstrate that, depending on the nature of the substituents on positions 3, 4, and 5, this scaffold leads to ligands that exert an intrinsic inverse agonist activity on GHSR-catalyzed G protein activation through the stabilization of a specific inactive receptor conformation. Thanks to an in vivo evaluation, we also show that one of the most promising ligands not only exerts an effect on insulin secretion in rat pancreatic islets but also affects the orexigenic effects of ghrelin in mice.Molecules capable of thermally activated delayed fluorescence (TADF) are promising as emitters in organic light-emitting devices. Processes leading to and competing with TADF in 4,5-di(9H-carbazol-9-yl)-phthalonitrile are analyzed in detail. It is demonstrated that the key features of an efficient TADF emitter include the presence of two triplet states of different natures with potential energy surfaces crossing between the T1 and S1 minima and a noticeable dependence of the S1 → S0 oscillator strength on molecular deformations from low-frequency antisymmetric vibrational modes. These conclusions can be useful in the targeted design of efficient TADF emitters.We have developed a synthetic route that uses sodium for the production of intermetallic Pt5Ce nanoparticles (ca. 6 nm average diameter) supported on carbon powder. Sodium melt was demonstrated to reduce a powder mixture of PtCl2 and CeCl3 to form submicrometer Pt5Ce particles with the simultaneous formation of NaCl. The NaCl-CeCl3 melt mixture and Na melt were formed during heating, which led to a uniform reaction between Pt and Ce, and the melt induced grain growth. The synthetic procedures were then modified to supply sodium vapor to the vicinity of the metal sources supported on carbon powder with an aim to suppress grain growth. Pt5Ce nanoparticles were successfully formed on the carbon support with high loading and dispersity.Lanthanide-containing functional complexes have found a variety of applications in materials science and biomedicine because of their unique electroptical and magnetic properties. However, the poor stability and solubility in water of multicomponent lanthanide organic assemblies significantly limit their practical applications. We report here a series of water-stable anionic Ln2nL3n-type (n = 2, 3, 4, and 5) lanthanide organic polyhedra (LOPs) constructed by deprotonation self-assembly of three fully conjugated ligands (H4L1 and H4L2a/b) featuring a 2,6-pyridine bitetrazolate chelating moiety. The outcomes of the LOPs formation reactions were found to be very sensitive toward the reaction conditions including base, metal source, solvents, and concentrations as characterized by a combination of NMR, high-resolution ESI-MS and X-ray crystallography. Ligands H4L2a/b manifested an excellent sensitization toward lanthanide ions (Ln = EuIII and TbIII), with high luminescent quantum yields for Tb8L2a12 (Φ = 11.2% in water) and Eu8L2b12 (Φ = 76.8% in DMSO) measured in polar solvents. Furthermore, due to the giant molecular weight and rigidity of the polyhedral skeleton, Gd8L2b12 showed a very high longitudinal relaxivity (r1) of 400.53 mM-1S-1. The performance of Gd8L2b12 as potential magnetic resonance imaging contrast agents (CAs) in vivo was evaluated with much longer retention time in the tumor sites compared with the commercial GdIII-based CAs. Dual-modal imaging potential has also been demonstrated with the mixed Eu/Gd LOPs. Our results not only provide a new design route toward water-stable multinuclear lanthanide organic assemblies but also offer potential candidates of supramolecular-edifices for bioimaging and drug delivery.Sessile droplet evaporation underpins a wide range of applications from inkjet printing to coating. However, drying times can be variable and contact-line pinning often leads to undesirable effects, such as ring stain formation. Here, we show voltage programmable control of contact angles during evaporation on two pinning-free surfaces. We use an electrowetting-on-dielectric approach and Slippery Liquid-Infused Porous (SLIP) and Slippery Omniphobic Covalently Attached Liquid-Like (SOCAL) surfaces to achieve a constant contact angle mode of evaporation. We report evaporation sequences and droplet lifetimes across a broad range of contact angles from 105°-67°. The values of the contact angles during evaporation are consistent with expectations from electrowetting and the Young-Lippman equation. The droplet contact areas reduce linearly in time, and this provides estimates of diffusion coefficients close to the expected literature value. We further find that the total time of evaporation over the broad contact angle range studied is only weakly dependent on the value of the contact angle. We conclude that on these types of slippery surfaces, droplet lifetimes can be predicted and controlled by the droplet's volume and physical properties (density, diffusion coefficient, and vapor concentration difference to the vapor phase) largely independent of the precise value of contact angle. These results are relevant to applications, such as printing, spraying, coating, and other processes, where controlling droplet evaporation and drying is important.