4,262 research outputs found
Rapid and efficient stable gene transfer to mesenchymal stromal cells using a modified foamy virus vector
Mesenchymal stromal cells (MSCs) hold great promise for regenerative medicine. Stable ex vivo gene transfer to MSCs could improve the outcome and scope of MSC therapy, but current vectors require multiple rounds of transduction, involve genotoxic viral promoters and/or the addition of cytotoxic cationic polymers in order to achieve efficient transduction. We describe a self-inactivating foamy virus vector (FVV), incorporating the simian macaque foamy virus envelope and using physiological promoters, which efficiently transduces murine MSCs (mMSCs) in a single-round. High and sustained expression of the transgene, whether GFP or the lysosomal enzyme, arylsulphatase A (ARSA), was achieved. Defining MSC characteristics (surface marker expression and differentiation potential), as well as long-term engraftment and distribution in the murine brain following intracerebroventricular delivery, are unaffected by FVV transduction. Similarly, greater than 95% of human MSCs (hMSCs) were stably transduced using the same vector, facilitating human application. This work describes the best stable gene transfer vector available for mMSCs and hMSCs
HI Absorption Toward HII Regions at Small Galactic Longitudes
We make a comprehensive study of HI absorption toward HII regions located
within Galactic longitudes less than 10 degrees. Structures in the extreme
inner Galaxy are traced using the longitude-velocity space distribution of this
absorption. We find significant HI absorption associated with the Near and Far
3kpc Arms, the Connecting Arm, Banias Clump 1 and the H I Tilted Disk. We also
constrain the line of sight distances to HII regions, by using HI absorption
spectra together with the HII region velocities measured by radio recombination
lines.Comment: Complete figure set available in online version of journal. Accepted
by ApJ August 8, 201
Noise Correlations in a Coulomb Blockaded Quantum Dot
We report measurements of current noise auto- and cross-correlation in a
tunable quantum dot with two or three leads. As the Coulomb blockade is lifted
at finite source-drain bias, the auto-correlation evolves from super-Poissonian
to sub-Poissonian in the two-lead case, and the cross-correlation evolves from
positive to negative in the three-lead case, consistent with transport through
multiple levels. Cross-correlations in the three-lead dot are found to be
proportional to the noise in excess of the Poissonian value in the limit of
weak output tunneling
Application of Thermal Storage, Peak Shaving and Cogeneration for Hospitals
Energy costs of hospitals can be managed by
employing various strategies to control peak
electrical demand (KW) while at the same time
providing additional security of operation in
the event that an equipment failure or a
disruption of power from the electric utility
occurs. Some electric utilities offer their
customers demand (KW) reduction rate incentives.
Many hospitals have additional emergency back-up
needs for electrical energy. Demand is
relatively constant in many hospitals due to
high internal loads. These factors coupled with
the present competitive alternate fuel market
and present opportunities for hospitals to
significantly reduce operating costs and provide
additional stand-by or back-up electric sources.
This paper employs a hospital case study to
define and illustrate three energy planning strategies applicable to hospitals. These
strategies are peak shaving, thermal storage,
cogeneration and/or paralleling with the
electric utility
Shot Noise in Graphene
We report measurements of current noise in single- and multi-layer graphene
devices. In four single-layer devices, including a p-n junction, the Fano
factor remains constant to within +/-10% upon varying carrier type and density,
and averages between 0.35 and 0.38. The Fano factor in a multi-layer device is
found to decrease from a maximal value of 0.33 at the charge-neutrality point
to 0.25 at high carrier density. These results are compared to theoretical
predictions for shot noise in ballistic and disordered graphene.Comment: related papers available at http://marcuslab.harvard.ed
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