We thought it might encourage participation.” Using lottery incentives to improve LibQUAL+(TM) response rates among students

Libraries deploying the LibQUAL+™ survey can offer a lottery incentive and many do in the hope of increasing response rates. Other libraries may be prohibited from offering one because of Institutional Review Board restrictions, as is the case at [institution name]. We wanted to discover why libraries offer lottery incentives and what kinds and if they believe these incentives have a positive impact on their response rates. The responding libraries hold a general belief that lottery incentives are effective but base this on feeling rather than research. We examine what the literature says about lottery incentives and student populations

alpha-nucleus potentials for the neutron-deficient p nuclei

alpha-nucleus potentials are one important ingredient for the understanding of the nucleosynthesis of heavy neutron-deficient p nuclei in the astrophysical gamma-process where these p nuclei are produced by a series of (gamma,n), (gamma,p), and (gamma,alpha) reactions. I present an improved alpha-nucleus potential at the astrophysically relevant sub-Coulomb energies which is derived from the analysis of alpha decay data and from a previously established systematic behavior of double-folding potentials.Comment: 6 pages, 3 figures, accepted for publication in Phys. Rev.

Layer-by-Layer Fabrication of Covalently Crosslinked and Reactive Polymer Multilayers Using Azlactone-Functionalized Copolymers: A Platform for the Design of Functional Biointerfaces

We report a method for modulating the physicochemical properties of surfaces that is based on the reactive layer-by-layer fabrication of covalently crosslinked thin films using azlactone-functionalized copolymers. We demonstrate that copolymers containing different molar ratios of methyl methacrylate (MMA) and 2-vinyl-4,4-dimethylazlactone (VDMA) can be alternately deposited with poly(ethyleneimine) to assemble covalently crosslinked thin films. Characterization using ellipsometry demonstrates that, in general, film growth and thickness decrease as the content of reactive, azlactone functionality in the copolymer used to assemble the film decreases. Reflective infrared spectroscopy experiments demonstrate that films fabricated from MMA:VDMA copolymers contain residual azlactone functionality and that these reactive groups can be exploited to modify film-coated surfaces. Fabricating films from MMA:VDMA copolymers containing different compositions permitted modulation of the density of reactive groups within the films and, thus, the extent to which the films are functionalized by exposure to small molecule amines. For example, functionalization of MMA:VDMA copolymer films with the small molecule D-glucamine resulted in films with water contact angles that varied with the composition of the copolymer used to fabricate the film (e.g., as the azlactone content in the film increased, glucamine-modified films became more hydrophilic). We demonstrate further that treatment of copolymer-containing films with glucamine resulted in changes in the numbers of mammalian cells that grow on the surfaces of the films. Our results suggest the basis of methods that could be used to modulate or tune the density of chemical and biological functionality presented on surfaces of interest in a variety of fundamental and applied contexts

Functionalization of Fibers Using Azlactone-Containing Polymers: Layer-by-Layer Fabrication of Reactive Thin Films on the Surfaces of Hair and Cellulose-Based Materials

We report an approach to the functionalization of fibers and fiber-based materials that is based on the deposition of reactive azlactone-functionalized polymers and the reactive layer-by-layer assembly of azlactone-containing thin films. We demonstrate (i) that the azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) can be used to modify the surfaces of a model protein-based fiber (horsehair) and cellulose-based materials (e.g., cotton and paper), and (ii) that fibers functionalized in this manner can be used to support the fabrication of covalently cross-linked and reactive polymer multilayers assembled using PVDMA and poly(ethyleneimine) (PEI). The growth, chemical reactivity, and uniformity of films deposited on these substrates were characterized using fluorescence microscopy, confocal microscopy, and scanning electron microscopy (SEM). In addition to the direct functionalization of fibers, we demonstrate that the residual azlactone functionality in PVDMA-treated or film-coated fibers can be exploited to chemically modify the surface chemistry and physicochemical properties of fiber-based materials postfabrication using amine functionalized molecules. For example, we demonstrate that this approach permits control over the surface properties of paper (e.g., absorption of water) by simple postfabrication treatment of film-coated paper with the hydrophobic amine n-decylamine. The azlactone functionality present in these materials provides a platform for the modification of polymer-treated and film-coated fibers with a broad range of other chemical and biological species (e.g., enzymes, peptides, catalysts, etc.). The results of this investigation thus provide a basis for the functionalization of fibers and fiber-based materials (e.g., textile fabrics or nonwoven mats) of potential utility in a broad range of consumer, industrial, and biomedical contexts

Azlactone-Functionalized Polymers as Reactive Platforms for the Design of Advanced Materials: Progress in the Last Ten Years

Polymers functionalized with azlactone (or oxazolone) functionality have become increasingly useful for the rapid and modular design of functional materials. Because azlactones can react via ring-opening reactions with a variety of different nucleophilic species (e.g., primary amines, hydroxyl groups, and thiol functionality), azlactone-functionalized materials can serve as convenient \u27reactive\u27 platforms for the post-synthesis or post-fabrication introduction of a broad range of chemical functionality to soluble polymers, insoluble supports, and surfaces/interfaces. The last decade has seen an increase in both the number and the variety of reports that exploit the properties and the reactivities of azlactone-functionalized polymers. Here, we highlight recent work from several different laboratories, including our own, toward the design and characterization of azlactone-functionalized polymers, with a particular emphasis on: (i) new synthetic approaches for the preparation of well-defined azlactone-functionalized polymers using living/controlled methods of polymerization, (ii) the design and modular synthesis of side-chain functionalized polymers and block copolymers via post-polymerization modification of azlactone-functionalized polymers, (iii) the development of reactive polymeric supports useful in the contexts of separations and catalysis, and (iv) methods for the fabrication of reactive thin films and other approaches to the immobilization of azlactone functionality on surfaces and interfaces. Examples discussed herein reveal a growing awareness of azlactone functionality as a useful tool for polymer chemists, and highlight several ways that the unique reactivity of these materials can both complement and provide useful alternatives to other reactive polymers currently used to design functional materials

Free-Standing and Reactive Thin Films Fabricated by Covalent Layer-by-Layer Assembly and Subsequent Lift-Off of Azlactone-Containing Polymer Multilayers

We report an approach to the fabrication of free-standing and amine-reactive thin films that is based on the reactive layer-by-layer assembly and subsequent lift-off of azlactone-containing polymer multilayers. We demonstrate that covalently cross-linked multilayers fabricated using the azlactone-functionalized polymer poly(2-vinyl-4,4-dimethylazlactone) (PVDMA) and a primary amine-containing polymer [poly(ethyleneimine) (PEI)] can be delaminated from planar glass and silicon surfaces by immersion in mildly acidic aqueous environments to yield flexible freestanding membranes. These free-standing membranes are robust and can withstand exposure to strong acid, strong base, or incubation in high ionic strength solutions that typically lead to the disruption and erosion of polymer multilayers assembled by reversible weak interactions (e.g., polyelectrolyte multilayers assembled by electrostatic interactions or hydrogen bonding). We demonstrate further that these PEI/PVDMA assemblies contain residual reactive azlactone functionality that can be exploited to chemically modify the films (either directly after fabrication or after they have been lifted off of the substrates on which they were fabricated) using a variety of amine-functionalized small molecules. These free-standing membranes can also be transferred readily onto other objects (for example, onto the surfaces of planar substrates containing holes or pores) to fabricate suspended polymer membranes and other film-functionalized interfaces. In addition to planar, two-dimensional free-standing films, this approach can be used to fabricate and isolate three-dimensional free-standing membranes (e.g., curved films or tubes) by layer-by-layer assembly on, and subsequent lift-off from, the surfaces of topologically complex substrates (e.g., the curved ends of glass tubing, etc.). The results of this investigation, when combined, suggest the basis of methods for the fabrication of stable, chemically reactive, and flexible polymer thin films and membranes of potential utility in a variety of fundamental and applied contexts

Reactive Layer-by-Layer Assembly of Suspended Thin Films and Semipermeable Membranes at Interfaces Created Between Aqueous and Organic Phases

Thin films of polymer suspended across the openings of pores, channels, and microcavities are of interest in a broad range of fundamental and applied contexts. A reactive layer-by-layer approach Is demonstrated for the fabrication of suspended thin films and semipermeable membranes that makes use of liquid/ liquid interfaces created between immiscible aqueous and organic phases as templates for film fabrication (see image). (Figure Presented)

Biological Regulation in the Formation of Hypoxia

2010 S.C. Water Resources Conference - Science and Policy Challenges for a Sustainable Futur

I\u27d Like To Meet Your Father

https://digitalcommons.library.umaine.edu/mmb-vp/1741/thumbnail.jp