All electron ab initio investigations of the electronic states of the MoN molecule

The low lying electronic states of the molecule MoN were investigated by performing all electron ab initio multi-configuration self-consistent-field (CASSCF) calculations. The relativistic corrections for the one electron Darwin contact term and the relativistic mass-velocity correction were determined in perturbation calculations. The electronic ground state is confirmed as being ⁴∑⁻. The chemical bond of MoN has a triple bond character because of the approximately fully occupied delocalized bonding π and σ orbitals. The spectroscopic constants for the ground state and ten excited states were derived. The excited doublet states ²∑⁻, ²Γ, ²Δ, and ²∑⁺ are found to be lower lying than the ⁴Π state that was investigated experimentally. Elaborate multi-configuration configuration-interaction (MRCI) calculations were carried out for the states ⁴∑⁻ and ⁴∏ using various basis sets. The spectroscopic constants for the ⁴∑⁻ ground state were determined as r_e=1.636 Å and ω_e=1109 cm⁻¹, and for the ⁴∏ state as r_e=1.662 Å and ω_e=941 cm⁻¹. The values for the ground state are in excellent agreement with available experimental data. The MoN molecule is polar with a charge transfer from Mo to N. The dipole moment was determined as 2.11 D in the ⁴∑⁻ state and as 4.60 D in the ⁴∏ state. These values agree well with the revised experimental values determined from molecular Stark spectroscopic measurements. The dissociation energy, D_e, is determined as 5.17 eV, and D₀ as 5.10 eV.     

Photochemical Crosslinking and Enzymatic Degradation of Poly(3‐hydroxyalkanoate)s for Micropatterning in Photolithography

Biodegradable poly(3‐hydroxyundecenoate) (PHU) films on silicon wafers were crosslinked with UV light under patterned masks. The films were crosslinked most efficiently when irradiated in the presence of diphenyl(2,4,6‐trimethylbenzoylphosphane oxide) as the initiator. Crosslinked patterns were developed with depolymerase solution because crosslinked PHU was degraded much more slowly than natural PHU. Patterned images with thicknesses of as low as 2.5 μm were obtained showing the potential application of PHU in microlithography as a photosensitive material, which is friendly to the environment.     

Three New Phthalide Glycosides from the Rhizomes of Cnidium officinale and Their Recovery Effect on Damaged Otic Hair Cells in Zebrafish

The extract from Cnidium officinale rhizomes was shown in a prior experiment to markedly recover otic hair cells in zebrafish damaged by neomycin. The current study was brought about to identify the principal metabolite. Column chromatography using octadecyl SiO₂ and SiO₂ was performed to isolate the major metabolites from the active fraction. The chemical structures were resolved on the basis of spectroscopic data, including NMR, IR, MS, and circular dichroism (CD) data. The isolated phthalide glycosides were assessed for their recovery effect on damaged otic hair cells in neomycin-treated zebrafish. Three new phthalide glycosides were isolated, and their chemical structures, including stereochemical characteristics, were determined. Two glycosides (0.1 μM) showed a recovery effect (p < 0.01) on otic hair cells in zebrafish affected by neomycin ototoxicity. Repeated column chromatography led to the isolation of three new phthalide glycosides, named ligusticosides C (1), D (2), and E (3). Ligusticoside C and ligusticoside E recovered damaged otic hair cells in zebrafish.     

SnO2 Quantum Dots Distributed along V2O5 Nanobelts for Utilization as a High-Capacity Storage Hybrid Material in Li-Ion Batteries

In this study, the facile synthesis of SnO₂ quantum dot (QD)-garnished V₂O₅ nanobelts exhibiting significantly enhanced reversible capacity and outstanding cyclic stability for Li⁺ storage was achieved. Electrochemical impedance analysis revealed strong charge transfer kinetics related to that of V₂O₅ nanobelts. The SnO₂ QD-garnished V₂O₅ nanobelts exhibited the highest discharge capacity of ca. 760 mAhg⁻¹ at a density of 441 mAg⁻¹ between the voltage ranges of 0.0 to 3.0 V, while the pristine V₂O₅ nanobelts samples recorded a discharge capacity of ca. 403 mAhg⁻¹. The high capacity of QD-garnished nanobelts was achieved as an outcome of their huge surface area of 50.49 m²g⁻¹ and improved electronic conductivity. Therefore, the as-presented SnO₂ QD-garnished V₂O₅ nanobelts synthesis strategy could produce an ideal material for application in high-performance Li-ion batteries.     

Fabrication of hydrophobic surface of titanium dioxide films by successive ionic layer adsorption and reaction (SILAR) method

Titanium dioxide (TiO₂) films were fabricated on fluorine doped tin oxide (FTO) coated glass substrate using successive ionic layer adsorption and reaction (SILAR) method. The X-ray diffraction, scanning electron microscopy, transmission electron microscopy, optical absorption and contact angle measurement were applied to study the structural, surface morphological, optical and surface wettability properties of the as-deposited and annealed TiO₂ films. The X-ray diffraction studies revealed both as-deposited and annealed TiO₂ films are amorphous. Irregular shaped spherical grains of random size and well covered to the fluorine doped tin oxide coated glass substrates were observed from SEM studies with some cracks after annealing. The optical band gap values of virgin TiO_2, annealed, methyl violet and rose bengal sensitized TiO₂ were found to be 3.6, 3.5, 2.87 and 2.95 eV, respectively. Surface wettability studied in contact with liquid interface, showed hydrophobic nature as water contact angles were greater than 90°. The adsorption of dyes, as confirmed by the photographs, is one of the prime requirements for dye sensitized solar cells (DSSC).     

A highly selective fluorescent chemosensor for silver(I) in water/ethanol mixture

Synthesis, photophysical, and complexation properties of fluorescent chemosensors, L¹ and L², with ‘receptor-spacer-fluorophore’ motif (L¹: NS₂O₂-cyclic receptor, L²: acyclic analogue receptor) are described. Maximum chelation-enhanced fluorescence effect (TURN-ON type) was observed in the presence of Ag⁺ for both fluoroionophores in a 1:1 (v/v) aqueous ethanol solution: remarkably superior selectivity of L¹ (150-fold) with cyclic receptor than that of the L² (50-fold) with acyclic analogue was found. According to the fluorescence and NMR titrations, the excellent selectivity of L¹ is attributed to its topology-based higher affinity in complexation.     

Approaches for application of sub and supercritical fluid extraction for quantification of orbifloxacin from plasma and milk: Application to disposition kinetics

Since its extensive development in the early 1980s, SFE has attracted considerable attention as a sample-preparation procedure. However, other different sample preparation procedures, including precipitation, liquid- and/or solid-phase extraction in biological fluids, also remain in use. In this investigation, SFE was introduced to isolate and identify orbifloxacin from plasma and milk. Four parameters, including the temperature and the pressure of supercritical fluid, modifier ratios, and dynamic extraction time, were evaluated and optimized to obtain the best yield of the analyte from the biological fluids. Determinations of the orbifloxacin (OBFX) in the extracts were carried out using HPLC-FLD. The optimum conditions of the extraction process that yielded the maximum analyte extraction efficiencies were 150 °C vs. 60 °C, 250 kg cm⁻², 30% vs. 35% methanol, and 40 min vs. 20 min, for plasma and milk, respectively. The linearity of the calibration curves as well as the instrument LODs/LOQs were evaluated. Good linearity (at least r² ≥ 0.999) of the calibration curves was obtained over the range from 0.2 to 0.01 μg mL⁻¹. The method showed a good recovery rate (74.2-127.73%) and precision (RSDs: 1.64-20%). The instrumental LOD and LOQ values were 0.004 μg mL⁻¹ vs. 0.01 μg mL⁻¹ or 0.006 μg mL⁻¹ vs. 0.02 μg mL⁻¹, for plasma and milk, respectively. The method was successfully applied to estimate the pharmacokinetic variables of orbifloxacin in lactating does. To the best of our knowledge, this is the first time that SFE has been applied to isolate an antimicrobial agent from biological fluids. This method is promising for clinical applications and for pharmacokinetic studies of various pharmaceuticals in biological fluids.