High-Density Peptide Arrays with Combinatorial Laser Fusing

Combinatorial laser fusing is a new method to produce high-density peptide arrays with feature sizes as small as 10 mu m. It combines the high spot densities achieved by lithographic methods with the cost-efficiency of biofunctional xerography. The method is also adapted for other small molecules compatible with solid phase synthesis

Trace elements in glucometabolic disorders: an update

Many trace elements, among which metals, are indispensable for proper functioning of a myriad of biochemical reactions, more particularly as enzyme cofactors. This is particularly true for the vast set of processes involved in regulation of glucose homeostasis, being it in glucose metabolism itself or in hormonal control, especially insulin. The role and importance of trace elements such as chromium, zinc, selenium, lithium and vanadium are much less evident and subjected to chronic debate. This review updates our actual knowledge concerning these five trace elements. A careful survey of the literature shows that while theoretical postulates from some key roles of these elements had led to real hopes for therapy of insulin resistance and diabetes, the limited experience based on available data indicates that beneficial effects and use of most of them are subjected to caution, given the narrow window between safe and unsafe doses. Clear therapeutic benefit in these pathologies is presently doubtful but some data indicate that these metals may have a clinical interest in patients presenting deficiencies in individual metal levels. The same holds true for an association of some trace elements such as chromium or zinc with oral antidiabetics. However, this area is essentially unexplored in adequate clinical trials, which are worth being performed

Different expectations: a comparative history of structure, experience, and strategic alliances in the U.S. and U.K. poultry sectors, 1920-1990

This comparative historical analysis demonstrates how memory and reflexive interpretations of the past can shape entrepreneurial willingness to collaborate with larger firms in an industry. Emphasizing the importance of spatial metaphors and periodization for developing historical knowledge, the paper focuses on how the historical space of experience explains how entrepreneurs make strategic choices regarding collaboration under conditions of complexity and uncertainty. Comparing the U.S. and U.K. emerging poultry sectors offers a methodologically novel analysis of an important but little‐studied agribusiness sector, offering a dual reading that compares two versions of historical reasoning both theoretically and empirically

The microstructure of hydrogen- and deuterium-doped nanocrystalline palladium studied by small-angle neutron scattering

By means of small-angle neutron scattering the microstructure of two nanocrystalline Pd samples (prepared by inert gas condensation) has been studied at room temperature in a Q-range from $10^{-3} { {\AA}}^{-1}$ to $0.4 { {\AA}}^{-1}$. An additional subsequent doping of the two samples with H as well as with D (concentrations < 4 at% ) caused contrast variations that provided more detailed structural information. The measured scattering intensity was modeled by a Porod contribution from large heterogenities (e.g. pores) and a contribution from spherical grains with a log-normal distribution of their radii. To account for the presence of grain boundaries, the grains were considered to be surrounded by a shell with a reduced Pd density and a thickness half as large as the thickness of the grain boundaries. For the above model, the data of the H-doped, D-doped and undoped sample were simultaneously fitted with one single set of adjustable parameters. The fits yielded for the two samples volume-weighted mean grain radii of 10 nm and 13 nm. The values for the grain boundary thickness lie between 0.2 and 0.8 nm. Almost all of the H- and D-atoms are, at low hydrogen concentrations, located in the grain boundaries

Three-cavity circuit studies of the Maryland gyroklystron

At the University of Maryland we have examined an X-Band TE[sub 01] mode three-cavity gyroklystron circuit that includes a tunable buncher cavity. The system parameters are: 425 kV, 100--200 A, pulse length [approximately] 1 [mu]s, operating frequency 9.85 GHz, and a beam alpha, [upsilon][perpendicular]/[upsilon][sub z], in the range 0.7--1.0. This circuit produced a maximum power of 27 MW at 32% efficiency and a gain of 36 dB. We will summarize the major results of the three-cavity systems, including recent output cavity configurations that were to affect the post-cavity interaction