Hugustafson9781

A neural network based quasi-diabatic potential energy matrix Hd that describes the photodissociation of formaldehyde involving the two lowest singlet states S0 and S1 is constructed. It has strict complete nuclear permutation inversion symmetry encoded and can reproduce high level ab initio electronic structure data, including energies, energy gradients, and derivative couplings, with excellent accuracy. It has been fully saturated in the configuration space to cover all possible reaction pathways with a trajectory-guided point sampling approach. This Hd will not only enable the accurate full-dimensional dynamic simulations of the photodissociation of formaldehyde involving S0 and S1 but also provide a crucial ingredient for incorporating spin-orbit couplings into a diabatic framework, thus ultimately enabling the study of both internal conversion and intersystem crossing in formaldehyde on the same footing.The monitoring of the emerging contaminant, microplastics, in the environment, in water supply, and for food safety is of major interest to science, consumers, and governments. While the chemical analysis of these particles is considered mandatory, a rapid and reliable method for the determination of particle sizes, shapes, and numbers is missing, as existing methods are not fitting into current laboratory measurement routines. In this study, we present an approach for circumventing these issues through the application of quantum cascade laser-based microscopy combined with an automated data analysis. This method allows the measurement of an area of 144 mm2 in 36 min, with a pixel resolution of 4.2 μm, which is an appropriate timeframe and spatial resolution for routine measurements. The performance was compared to the existing state-of-the-art Fourier transform infrared microscopy analyses. Further, the application of the method on various environmental samples was investigated to examine its capacity to provide number and variety of present particles. The described analytical procedure overcomes the last restrictions for schedulable and rapid microplastic monitoring, resulting in a highly detailed data set for particle numbers, particle shapes, and polymer types.Bicontinuous interfacially jammed emulsion gels ("bijels") are a new class of soft matter containing two interpenetrating continuous phases. They have great potential for applications in many areas. However, difficulties in fabricating bijels and controlling structural features of interest have posed severe barriers to their wide applications. In this study, a phase inversion-based technique was developed for fabricating bijels and bijels-derived structures. The effects of varying the composition of casting solutions for the fabrication of bijels on the porosity, oil-to-water percentage, and domain size of bijels were investigated. Composite bijels prepared from two organic monomers were also made, demonstrating the flexibility of the phase inversion-based technique for the fabrication of bijels. Interestingly, the incorporation of a second monomer into the casting solution also affected the porosity and domain size of bijels formed, which may provide a new strategy for the controlled fabrication of bijels. Doxorubicin hydrochloride (DOX, as a model drug)-loaded bijels-derived hybrid hydrogels comprising two continuous phases were successfully made, with one phase being cross-linked alginate that carried the drug. Controlled release of DOX from the bijels-derived structures could be achieved. In vitro degradation study indicated that cross-linking of alginate in bijels-derived hybrid hydrogels controlled alginate degradation, thereby affecting the DOX release behavior. Our current work has provided a facile and reproducible protocol for the controlled fabrication of bijels and bijels-derived structures, which facilitates expanding their applications in the biomedical field.Ackee fruits (Blighia sapida), an important food source in some tropical countries, can be the cause of serious poisoning. Ackees contain hypoglycin A and methylenecyclopropylglycine. Experiments were undertaken by a volunteer to elucidate the metabolic details of poisoning. Rapid intestinal absorption of the toxins was followed by their slow degradation to methylenecyclopropylacetyl and methylenecyclopropylformyl conjugates. Impairment of the metabolism of branched chain amino acids and ß-oxidation of fatty acids was found. Reduced enzyme activities were observed for several days after ingestion. A defined dose of fruit material caused significantly higher concentrations of metabolites when consumed 24 h after a previous ingestion than when consumed only once. The accumulation of toxins, toxin metabolites, and products of the intermediate metabolism after repeated consumption may, at least partly, explain the high frequency of fatal cases observed during harvesting. No inhibition of enzymes that degrade long-chain acyl compounds was observed in the experiments.Spin-momentum locking is a peculiar effect in the near-field of guided optical or plasmonic modes. It can be utilized to map the spinning or handedness of electromagnetic fields onto the propagation direction. This motivates a method to probe the circular dichroism of an illuminated chiral object. In this work, we demonstrate local, subdiffraction limited chiral coupling of light and propagating surface plasmon polaritons in a self-assembled system of a gold nanoantenna and a silver nanowire. A thin silica shell around the nanowire provides precise distance control and also serves as a host for fluorescent molecules, which indicate the direction of plasmon propagation. We characterize our nanoantenna-nanowire systems comprehensively through correlated electron microscopy, energy-dispersive X-ray spectroscopy, dark-field, and fluorescence imaging. Three-dimensional numerical simulations support the experimental findings. Besides our measurement of far-field polarization, we estimate sensing capabilities and derive not only a sensitivity of 1 mdeg for the ellipticity of the light field, but also find 103 deg cm2/dmol for the circular dichroism of an analyte locally introduced in the hot spot of the antenna-wire system. Thorough modeling of a prototypical design predicts on-chip sensing of chiral analytes. PRGL493 This introduces our system as an ultracompact sensor for chiral response far below the diffraction limit.Two ferrocenyl derivatives, Fc-CA and Fc-FA, were synthesized by a condensation reaction between the amino ferrocene and hydroxycinnamic acids, that is, caffeic acid (CA) and ferulic acid (FA). The structures and purity of all compounds were characterized by 1H- and 13C NMR spectroscopies, Mass spectrometry (MS), and elemental analysis. The antioxidant properties of Fc-CA and Fc-FA and of its ligand were studied for free radical scavenging activity toward DPPH•, superoxide anion (O2•-), NO•, and ABTS•+ by UV-vis and electron spin resonance spectroscopies. The cytotoxicity of Fc-CA and Fc-FA against MCF-7 and MDA-MB-231 breast cancer cells and MRC-5 human lung fibroblasts cell was higher than that of cisplatin. The geometry and electronic structures of all compounds were then simulated using density functional theory at M05-2X/6-311+G(d,p) level of theory. Thermodynamics of the free radical quenching reactions by common mechanisms reveal the higher antioxidant properties of the Fc-CA and Fc-FA in comparison to their ligands. An in-depth study of the free radical scavenging activity against HOO• and HO• radicals was performed for two of the most favorable and competitive mechanisms, the hydrogen transfer (either hydrogen atom transfer or proton-coupled electron transfer mechanisms) and the radical adduct formation. The in silico studies indicated that ferrocenyl derivatives exhibited prominent binding affinity to protein models in comparison to CA and FA. Their dock scores were notable at ligand binding sites of ERα, Erβ, and JAK2 proteins. Dock pose analysis also shed light into the possible mechanism of action for the studied compounds.This work demonstrates a novel strategy to improve the sensing performance of a prism-coupled surface plasmon resonance system by Gaussian beam shaping and multivariate data analysis. The propagation of the beam along the optical system has been studied using the Gaussian beam approximation to design the incident beam such that the beam waist is aligned precisely and that stability is assured at the metal-dielectric interface. This renders a collimated incident beam, hence least angular dispersion, yielding a stronger and sharper plasmonic resonance. Moreover, we use the multivariate analysis method partial least squares that combines multiple features of the surface plasmon resonance curve and allows for a more precise analysis of the plasmonic response. link2 Compared to univariate analysis, partial least squares improves typical sensing performance parameters remarkably. The combination of both aspects, beam shaping and multivariate analysis, overcomes current limitations of plasmonic detection systems. Thereby, we improve analytical sensitivity by a factor of 16, decrease the prediction error of the concentration of an unknown analyte by a factor of 11, and enhance resolution to the order of 5 × 10-7 RIU in angular interrogation.X-ray absorption spectroscopy (XAS) has been employed to study the coordination of the Ag+ ion in aqueous solution. The conjunction of extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) data analysis provided results suggesting the preference for a first shell linear coordination with a mean Ag-O bond distance of 2.34(2) Å, different from the first generally accepted tetrahedral model with a longer mean Ag-O bond distance. Ab initio molecular dynamics simulations with the Car-Parrinello approach (CPMD) were also performed and were able to describe the coordination of the hydrated Ag+ ion in aqueous solution in very good agreement with the experimental data. The high sensitivity for the closest environment of the photoabsorber of the EXAFS and XANES techniques, together with the long-range information provided by CPMD and large-angle X-ray scattering (LAXS), allowed us to reconstruct the three-dimensional model of the coordination geometry around the Ag+ ion in aqueous solution. The obtained results from experiments and theoretical simulations provided a complex picture with a certain amount of water molecules with high configurational disorder at distances comprised between the first and second hydration spheres. This evidence may have caused the proliferation of the coordination numbers that have been proposed so far for Ag+ in water. Altogether these data show how the description of the hydration of the Ag+ ion in aqueous solution can be complex, differently from other metal species where hydration structures can be described by clusters with well-defined geometries. link3 This diffuse hydration shell causes the Ag-O bond distance in the linear [Ag(H2O)2]+ ion to be ca. 0.2 Å longer than in isolated ions in solid state.The paramount challenge in design and synthesis of materials for vapor-phase elemental mercury (Hg0) immobilization is to achieve a balance between performance and economy for practical applications. Herein, a newly designed electroless plating coupled with an in situ selenization method was developed to construct a copper selenide (Cu2Se)-functionalized commercial polyurethane sponge (PUS) as an efficient Hg0 trap. Intrinsic features such as easy availability of the raw material, facile preparation, and excellent performance guarantee the Cu2Se/PUS to be applicable in industrial uses. The Cu2Se/PUS exhibits a maximum adsorption capacity (Qm,Cu2Se/PUS) of 25.90 mg·g-1, while this value is 758.80 mg·g-1 when normalized to the Cu2Se coating amount. This value of Qm,Cu2Se is equal to 79.7% of its corresponding theoretical value (Qt,Cu2Se), far exceeding the availability of Cu2Se anchored on other supports. Meanwhile, the Cu2Se/PUS exhibited a quick response for Hg0, with an extremely high uptake rate of 1275.84 μg·g-1·min-1.