A combined multiple-SLED broadband light source at 1300 nm for high resolution optical coherence tomography

We demonstrate a compact, inexpensive, and reliable fiber-coupled light source with broad bandwidth and sufficient power at 1300 nm for high resolution optical coherence tomography (OCT) imaging in real-time applications. By combining four superluminescent diodes (SLEDs) with different central wavelengths, the light source has a bandwidth of 145 nm centered at 1325 nm with over 10 mW of power. OCT images of an excised stage 30 embryonic chick heart acquired with our combined SLED light source (<5 μm axial resolution in tissue) are compared with images obtained with a single SLED source (∼10 μm axial resolution in tissue). The high resolution OCT system with the combined SLED light source provides better image quality (smaller speckle noise) and a greater ability to observe fine structures in the embryonic heart.     

Conversion electron cascades in 254(102)No

The spectrum of prompt conversion electrons emitted by excited 254No nuclei has been measured, revealing discrete lines arising from transitions within the ground state band. A striking feature is a broad distribution that peaks near 100 keV and comprises high multiplicity electron cascades, probably originating from M1 transitions within rotational bands built on high K states.     

Analysis of cylindrical shells of nonuniform thickness using two-dimensional photoelastic models

An experimental method is described whereby symmetrically loaded cylinders of nonuniform thickness are analyzed using two-dimensional photoelastic models mounted on elastic foundations. The technique is most conveniently applied to ring-stiffened or notched cylinders. The particular model studied simulated a notched cylindrical pressure vessel which had been previously studied with three-dimensional photoelasticity. The stress-concentration factors at the base of the notch, found using both methods, showed excellent agreement. An analysis was also performed which allows estimation of the error involved when a beam-on-elastic-foundation model does not rigorously simulate a cylinder.     

New fascaplysin-based CDK4-specific inhibitors: design, synthesis and biological activity

The first biologically active non-planar analogues of the toxic anti-cancer agent, fascaplysin, have been produced; we present the design, synthesis and biological activity of three tryptamine derivatives.     

Baryon exotics in the quark model, the skyrme model, and QCD

We derive the quantum numbers of baryon exotics in the quark model and the Skyrme model and show that they agree for arbitrary colors and flavors. We define exoticness E, which can be used to classify the states. The exotic baryons include the recently discovered qqqqq pentaquarks (E=1), as well as exotic baryons with additional qq pairs (E>/=1). The mass formula for nonexotic and exotic baryons is given as an expansion in 1/N(c) and allows one to relate the moment of inertia of the Skyrme soliton to the mass of a constituent quark.     

Driving forces for self-organized coadsorption: C6H6/2O and C6H6/2CO on Ni[111

The self-organized (2log3 x 2log3) coadsorbed phases of C(6)H(6) with O and with CO are investigated within first-principles density functional theory. The main driving force for formation of the C(6)H(6)/2O phase is found to be the reduction of O adatom repulsive interactions, while for the C(6)H(6)/2CO phase it is the interspecies attractive interactions and benzene-benzene repulsive interactions which are most important.