Fabrication,chemical modification,and topographical patterning of reactive gels assembled from azlactone‐functionalized polymers and a diamine

The work reported here demonstrates an approach to the fabrication of chemically reactive and topographically patterned hydrogels using the azlactone‐functionalized polymer poly(2‐vinyl‐4,4'‐dimethylazlactone) (PVDMA) and the hydrophilic diamine Jeffamine®. Gels were initially assembled in DMSO but can be subsequently transferred into aqueous media to form hydrogels. Spectroscopic characterization of assembled gels demonstrated that variation in the stoichiometric ratio of azlactones to amines during gel synthesis permits control over the extent of crosslinking in the gels. Residual azlactones not consumed during crosslinking can be exploited to further functionalize these gels with hydrophobic, hydrophilic, and macromolecular amines that influence the physicochemical properties of these materials in aqueous solvents. The surface and bulk of these gels can be differentially functionalized (i.e., different functional groups on the gel surface relative to the bulk) by taking advantage of different rates of diffusion of macromolecular amines versus small molecule amines into assembled gels. Finally, these azlactone‐functionalized gels can be topographically patterned with microwell arrays using a replica molding technique and chemically modified postfabrication with amine nucleophiles. This reactive approach to the fabrication of topographically patterned and chemically functionalized hydrogels offers a straightforward method for the rapid synthesis of micropatterned scaffolds of interest in a broad range of applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3185–3194     

Regioselective synthesis of pyrimidine-fused tetrahydropyridines and pyridines by microwave-assisted one-pot reaction

Molecular Diversity - A regioselective three-component reaction of α,β-unsaturated aldehydes, cyclic 1,3-dicarbonyls and 6-aminouracils in the presence of FeCl3·6H2O as catalyst...     

An unusual intramolecular hetero-Diels-Alder cycloaddition

A new reaction of erythronolides, an intramolecular hetero-Diels-Alder, has been discovered. Heated aqueous alcoholic solutions of ABT-773 (1) and its cis isomer (3) convert slowly to cycloadducts 2 and 4, respectively. Optimal reaction conditions, mechanistic studies supported by molecular modeling, and biological activity data are reported. Single-crystal X-ray structures for both adducts 2 and 4 have been obtained.     

Semi-leptonic decays of charmed mesons produced in γN collisions

We report here on a study of the characteristics of the semileptonic decay spectra from a pair of charmed hadrons produced via photoproduction. The inclusive production of charmed hadrons is phenomenologically parametrized as e^?aze^?bp_t2. Their decays are described by (i) decay of free charm quark in GIM, (ii) K¹ dominant mode, $\text{D}\text{→}\text{K}{}^1\text{l}\text{ν}$, and (iii) pure leptonic decays. We deduce that 〈M_eμ²〉 = 0.18 M_D² for free quark decay and 〈M_eμ²〉 = ?0.35 +-0.24 M_D² for K¹ dominant decay. For the specific purpose of the photoproduction experiment at FNAL whicc is currently searching for μe events, we incorporate the incident photon spectrum, and the decay distributions with and without the experimental acceptance criteria are presented.     

On the inverse Laplace transform of the product of a general class of polynomials and the multivariable H-function

In this paper we evaluate the inverse Laplace transform of $$\begin{gathered} s^{ - \eta } (s^{l_1 } + \lambda _1 )^{ - \sigma } (s^{l_2 } + \lambda _2 )^{ - \rho } \hfill \\ \times S_n^m [xs^{ - W} (S^{l_1 } + \lambda _1 )^{ - \upsilon } (S^{l_2 } + \lambda _2 )^{ - w} ]S_{n'}^{m'} [ys^{ - w'} (S^{l_1 } + \lambda _1 )^{ - \upsilon '} (S^{l_2 } + \lambda _2 )^{ - w_r } ] \hfill \\ \times H[z_1 s^{ - W_1 } (S^{l_1 } + \lambda _1 )^{ - \upsilon _1 } (S^{l_2 } + \lambda _2 )^{ - w_1 } ,...,z_r s^{ - w_r } (S^{l_1 } + \lambda _1 )^{ - \upsilon _r } (S^{l_2 } + \lambda _2 )^{ - w'} ] \hfill \\ \end{gathered} $$ Due to the general nature of the multivariable H-function involved herein, the inverse Laplace transform of the product of a large number of special functions involving one or more variables, occurring frequently in the problems of theoretical physics and engineering sciences can be obtained as simple special cases of our main findings. For the sake of illustration, we obtain here the inverse Laplace transform of a product of the Hermite polynomials, the Jacobi polynomials andr different modified Bessel functions of the second kind. A theorem obtained by Srivastava and Singh[7] follows as a special case of our main result.