An acenaphthopyrrolone-dipicolylamine derivative as a selective and sensitive chemosensor for group IIB cations

The recently reported acenaphthopyrrolone (ACNP) class of fluorophores have remarkably bright emission in the red end of the visible spectrum. We demonstrated that straightforward derivatization with 2-aminoethyl-dipicolylamine yields a selective and sensitive chemosensor for Zn(II), Cd(II) and Hg(II) ions. Further modifications could result in water-soluble derivatives, with practical applications in intracellular imaging of Zn(II) concentrations.     

Carbodeoxygenation of Biomass: The Carbonylation of Glycerol and Higher Polyols to Monocarboxylic Acids

Glycerol is converted to a mixture of butyric and isobutyric acid by rhodium‐ or iridium‐catalysed carbonylation using HI as the co‐catalyst. The initial reaction of glycerol with HI results in several intermediates that lead to isopropyl iodide, which upon carbonylation forms butyric and isobutyric acid. At low HI concentration, the intermediate allyl iodide undergoes carbonylation to give vinyl acetic acid and crotonic acid. Higher polyols C_nH_n+2(OH)_n are carbonylated to the corresponding C_n+1 mono‐carboxylic acids.     

The comparison of parametric and nonparametric bootstrap methods for reference interval computation in small sample size groups

According to the IFCC, to determine the population-based reference interval (RI) of a test, 120 reference individuals are required. However, for some age groups such as newborns and preterm babies, it is difficult to obtain enough reference individuals. In this study, we consider both parametric and nonparametric bootstrap methods for estimating RIs and the associated confidence intervals (CIs) in small sample size groups. We used data from four different tests [glucose, creatinine, blood urea nitrogen (BUN), and triglycerides], each in 120 individuals, to calculate the RIs and the associated CIs using nonparametric and parametric approaches. Also for each test, we selected small groups (m = 20, 30,…, 120) from among the 120 individuals and applied parametric and nonparametric bootstrap methods. The glucose and creatinine data were normally distributed, and the parametric bootstrap method provided more precise RIs (i.e., the associated CIs were narrower). In contrast, the BUN and triglyceride data were not normally distributed, and the nonparametric bootstrap method provided better results. With the bootstrap methods, the RIs and CIs of small groups were similar to those of the 120 subjects required for the nonparametric method, with a slight loss of precision. For original data with normal or close to normal distribution, the parametric bootstrap approach should be used, instead of nonparametric methods. For original data that deviate significantly from a normal distribution, the nonparametric bootstrap should be applied. Using the bootstrap methods, fewer samples are required for computing RIs, with only a slightly increased uncertainty around the end points.     

A note on the matrix Sturm‐Liouville operators with principal functions

In this study, we take under investigation principal functions corresponding to the eigenvalues and the spectral singularities of the Operator L generated in by the differential expression and the boundary condition (A₀ + A₁λ + A₂λ²)y^′(0,λ) ? (B₀ + B₁λ + B₂λ²)y(0,λ) = 0, where Q is a matrix‐valued function and A_i,B_i,i = 0,1,2 are non‐selfadjoint matrices also A₂,B₂ are invertible.     

Multiple analogues of binomial coefficients and families of related special numbers

Multiple $qt$-binomial coefficients and multiple analogues of several celebrated families of related special numbers are constructed in this paper. These higher-dimensional generalizations include the first and the second kind of $qt$-Stirling numbers, $qt$-Bell numbers, $qt$-Bernoulli numbers, $qt$-Catalan numbers and the $qt$-Fibonacci numbers. Certain significant applications are also studied including two discrete probability measures on the set of all integer partitions.     

Non-selfadjoint matrix Sturm-Liouville operators with spectral singularities

In this paper we investigate discrete spectrum of the non-selfadjoint matrix Sturm-Liouville operator L generated in L²(R₊,S) by the differential expression

     

Bright spatial solitons on a partially incoherent background

We present the first observation of incoherent antidark spatial solitons in noninstantaneous nonlinear media. This new class of soliton states involves bright solitons on a partially incoherent background of infinite extent. In the case where the nonlinearity is of the Kerr type, their existence is demonstrated analytically by means of an exact solution. Computer simulations and experiments indicate that these incoherent antidark solitons can propagate in a stable fashion provided that the spatial coherence of their background is reduced below the incoherent modulation instability threshold.     

Systematic Investigation of the Effect of Polymerization Routes on the Gas‐Sorption Properties of Nanoporous Azobenzene Polymers

Functional‐group‐oriented polymerization strategies have contributed significantly to the initial development of porous polymers and have led to the utilization of several well‐known organic transformations in the synthesis of these polymers. Because there are multiple polymerization routes that can be used to introduce the same chemical functionality, it is very important to demonstrate the effect of different polymerization routes on the gas‐sorption properties of these chemically similar polymers. Herein, we have studied the rich chemistry of azobenzenes and synthesized four chemically similar nanoporous azobenzene polymers (NABs) with surface areas of up to 1021 m² g^?1. The polymerization routes have a significant impact on the pore‐size distributions of the NABs, which directly affects the temperature dependence of the CO₂/N₂ selectivity. A pore‐width maximum of 6–8 Å, narrow pore‐size distribution, and small particle size (20–30 nm) were very critical for high CO₂/N₂ selectivity and N₂ phobicity, which is associated with azo linkages and realized at warm temperatures. Our findings collectively suggest that an investigation of different polymerization routes for the same chemical functionalization is critical to understand fully the combined effect of textural properties, local environment, and chemical functionalization on the gas‐sorption properties of nanoporous polymers.     

A Three‐Dimensional Porous Organic Semiconductor Based on Fully sp2‐Hybridized Graphitic Polymer

Dimensionality plays an important role in the charge transport properties of organic semiconductors. Although three‐dimensional semiconductors, such as Si, are common in inorganic materials, imparting electrical conductivity to covalent three‐dimensional organic polymers is challenging. Now, the synthesis of a three‐dimensional π‐conjugated porous organic polymer (3D p‐POP) using catalyst‐free Diels–Alder cycloaddition polymerization followed by acid‐promoted aromatization is presented. With a surface area of 801 m² g^?1, full conjugation throughout the carbon backbone, and an electrical conductivity of 6(2)×10^?4 S cm^?1 upon treatment with I₂ vapor, the 3D p‐POP is the first member of a new class of permanently porous 3D organic semiconductors.