New interpretation of Penning spectra from alkali-metal atoms chemisorbed on metal surfaces

Penning deexcitation spectra of alkali atoms adsorbed on metals show an intense peak at the Fermi level for coverages around the work-function minimum. This strong electron emission is assigned to the decay of a core-excited negative He-ion created by resonance transition of a substrate electron into the affinity level of the metastable rare-gas atom. The formation of this species also easily provides an explanation for the observed He* singlet-triplet conversion

Effects of noise upon human information processing

Studies of noise effects upon human information processing are described which investigated whether or not effects of noise upon performance are dependent upon specific characteristics of noise stimulation and their interaction with task conditions. The difficulty of predicting noise effects was emphasized. Arousal theory was considered to have explanatory value in interpreting the findings of all the studies. Performance under noise was found to involve a psychophysiological cost, measured by vasoconstriction response, with the degree of response cost being related to scores on a noise annoyance sensitivity scale. Noise sensitive subjects showed a greater autonomic response under noise stimulation

Communications Biophysics

Contains reports on one research project.National Institutes of Health (Grant 2 TO1 GM01555-06

The Missouri farm real estate situation for 1931-1932

Publication authorized September 7, 1933."The text of this bulletin represents a revision of a manuscript with the same title submitted originally by Mr. Moore to the Graduate School of the University of Missouri in partial fulfillment of the requirements for the Degree of Master of Arts"--P. [3].Digitized 2007 AES.Includes bibliographical references

The Missouri farm real estate situation for 1930-1931

Publication authorized July 12, 1932."The text of this bulletin represents a revision of a manuscript with the same title submitted originally by Mr. Callaway to the Graduate School of the University of Missouri in partial fulfillment of the requirements for the Degree of Master of Arts"--P. [5].Digitized 2007 AES.Includes bibliographical references

Regulation of the IgE response

IgE was the last of the five immunoglobulin classes to be discovered and is the antibody that is responsible for much of human type I allergic disease. This review summarizes recent developments with respect to control of IgE synthesis with an emphasis on Th2 (T helper 2) control and regulation using IgE Fc receptors

Synthesis and Cell Adhesive Properties of Linear and Cyclic RGD Functionalized Polynorbornene Thin Films

Described herein is the efficient synthesis and evaluation of bioactive arginine-glycine-aspartic acid (RGD) functionalized polynorbornene-based materials for cell adhesion and spreading. Polynorbornenes containing either linear or cyclic RGD peptides were synthesized by ring-opening metathesis polymerization (ROMP) using the well-defined ruthenium initiator [(H_(2)IMes)(pyr)_(2)(Cl)_(2)Ru═CHPh]. The random copolymerization of three separate norbornene monomers allowed for the incorporation of water-soluble polyethylene glycol (PEG) moieties, RGD cell recognition motifs, and primary amines for postpolymerization cross-linking. Following polymer synthesis, thin-film hydrogels were formed by cross-linking with bis(sulfosuccinimidyl) suberate (BS^3), and the ability of these materials to support human umbilical vein endothelial cell (HUVEC) adhesion and spreading was evaluated and quantified. When compared to control polymers containing either no peptide or a scrambled RDG peptide, polymers with linear or cyclic RGD at varying concentrations displayed excellent cell adhesive properties in both serum-supplemented and serum-free media. Polymers with cyclic RGD side chains maintained cell adhesion and exhibited comparable integrin binding at a 100-fold lower concentration than those carrying linear RGD peptides. The precise control of monomer incorporation enabled by ROMP allows for quantification of the impact of RGD structure and concentration on cell adhesion and spreading. The results presented here will serve to guide future efforts for the design of RGD functionalized materials with applications in surgery, tissue engineering, and regenerative medicine

The structural properties of the multi-layer graphene/4H-SiC(000-1) system as determined by Surface X-ray Diffraction

We present a structural analysis of the multi-layer graphene-4HSiC(000-1}) system using Surface X-Ray Reflectivity. We show for the first time that graphene films grown on the C-terminated (000-1}) surface have a graphene-substrate bond length that is very short (0.162nm). The measured distance rules out a weak Van der Waals interaction to the substrate and instead indicates a strong bond between the first graphene layer and the bulk as predicted by ab-initio calculations. The measurements also indicate that multi-layer graphene grows in a near turbostratic mode on this surface. This result may explain the lack of a broken graphene symmetry inferred from conduction measurements on this system [C. Berger et al., Science 312, 1191 (2006)].Comment: 9 pages with 6 figure