135 research outputs found
Experimental Microfluidic System
The ultimate goal of this project is to integrate microfluidic devices with NASA's space bioreactor systems. In such a system, the microfluidic device would provide realtime feedback control of the bioreactor by monitoring pH, glucose, and lactate levels in the cell media; and would provide an analytical capability to the bioreactor in exterrestrial environments for monitoring bioengineered cell products and health changes in cells due to environmental stressors. Such integrated systems could be used as biosentinels both in space and on planet surfaces. The objective is to demonstrate the ability of microfabricated devices to repeatedly and reproducibly perform bead cytometry experiments in micro, lunar, martian, and hypergravity (1.8g)
Study of Adolescent Self-Concept: Consistency In and Out of the Academic Setting
Educational Psycholog
Inclusion of Enclosed Hydration Effects in the Binding Free Energy Estimation of Dopamine D3 Receptor Complexes
Confined hydration and conformational flexibility are some of the challenges
encountered for the rational design of selective antagonists of G-protein
coupled receptors. We present a set of C3-substituted (-)-stepholidine
derivatives as potent binders of the dopamine D3 receptor. The compounds are
characterized biochemically, as well as by computer modeling using a novel
molecular dynamics-based alchemical binding free energy approach which
incorporates the effect of the displacement of enclosed water molecules from
the binding site. The free energy of displacement of specific hydration sites
is obtained using the Hydration Site Analysis method with explicit solvation.
This work underscores the critical role of confined hydration and
conformational reorganization in the molecular recognition mechanism of
dopamine receptors and illustrates the potential of binding free energy models
to represent these key phenomena.Comment: This is the first report of using enclosed hydration in estimating
binding free energies of protein-ligand complexes using implicit solvatio
A near infrared frequency comb for Y+J band astronomical spectroscopy
Radial velocity (RV) surveys supported by high precision wavelength
references (notably ThAr lamps and I2 cells) have successfully identified
hundreds of exoplanets; however, as the search for exoplanets moves to cooler,
lower mass stars, the optimum wave band for observation for these objects moves
into the near infrared (NIR) and new wavelength standards are required. To
address this need we are following up our successful deployment of an H
band(1.45-1.7{\mu}m) laser frequency comb based wavelength reference with a
comb working in the Y and J bands (0.98-1.3{\mu}m). This comb will be optimized
for use with a 50,000 resolution NIR spectrograph such as the Penn State
Habitable Zone Planet Finder. We present design and performance details of the
current Y+J band comb.Comment: Submitted to SPIE, conference proceedings 845
Near field modal noise reduction using annealed optical fiber
Incomplete and unstable mode population has long complicated the application of optical fiber for transferring star and calibration light to high precision spectrographs. The need for improved precision calibrators in support of radial velocity planet surveys has led to the introduction of coherent wavelengths sources using single mode fibers that are then coupled into multi-mode fibers, further exacerbating this problem. We explore mode scrambling in annealed optical fiber with and without agitation, as compared to that obtained using octagonal fiber and using an integrating sphere. We observe improved scrambling with annealed fibers compared to conventional and octagonal fibers
Differential Deposition for Figure-Corrections in Grazing-Incidence X-Ray Optics
No abstract availabl
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