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Preliminary results from the dust flux monitoring instrument during the encounter of Stardust spacecraft with Wild-2 comet
On January 2, 2004, the Stardust spacecraft successfully encountered the Wild-2 comet. The Dust Flux Monitoring Instrument (DFMI) provided quantitative measurements of dust particle fluxes and particle mass distributions throughout the entire flythrough
Creating a Perioperative Glycemic Control Program
Hyperglycemia in the surgical population is a recognized risk factor for postoperative complications; however, there is little literature to date regarding the management of hyperglycemia in the perioperative period. Here, we detail the strategies that our institutions have employed to identify and treat hyperglycemia in patients with diabetes who present for surgery. Our approach focuses on the recognition of hyperglycemia and metabolic abnormalities, control of glucose levels via insulin infusion when needed, monitoring for hypoglycemia and a comprehensive multidisciplinary approach that provides standardized recommendations for patients at all points in care as they transition from the preoperative clinic into the operating room, and then into the hospital
Electrophysiology of glioma: a Rho GTPase-activating protein reduces tumor growth and spares neuron structure and function
Background. Glioblastomas are the most aggressive type of brain tumor. A successful treatment should aim at halting tumor growth and protecting neuronal cells to prevent functional deficits and cognitive deterioration. Here, we exploited a Rho GTPase-activating bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), to interfere with glioma cell growth in vitro and vivo. We also investigated whether this toxin spares neuron structure and function in peritumoral areas. Methods. We performed a microarray transcriptomic and in-depth proteomic analysis to characterize the molecular changes triggered by CNF1 in glioma cells. We also examined tumor cell senescence and growth in vehicle-and CNF1-treated glioma-bearing mice. Electrophysiological and morphological techniques were used to investigate neuronal alterations in peritumoral cortical areas. Results. Administration of CNF1 triggered molecular and morphological hallmarks of senescence in mouse and human glioma cells in vitro. CNF1 treatment in vivo induced glioma cell senescence and potently reduced tumor volumes. In peritumoral areas of glioma-bearing mice, neurons showed a shrunken dendritic arbor and severe functional alterations such as increased spontaneous activity and reduced visual responsiveness. CNF1 treatment enhanced dendritic length and improved several physiological properties of pyramidal neurons, demonstrating functional preservation of the cortical network. Conclusions. Our findings demonstrate that CNF1 reduces glioma volume while at the same time maintaining the physiological and structural properties of peritumoral neurons. These data indicate a promising strategy for the development of more effective antiglioma therapies
Frequency dispersion reduction and bond conversion on n-type GaAs by in situ surface oxide removal and passivation
The method of surface preparation on n-type GaAs, even with the presence of an amorphous-Si interfacial passivation layer, is shown to be a critical step in the removal of accumulation capacitance frequency dispersion. In situ deposition and analysis techniques were used to study different surface preparations, including NH4OH, Si-flux, and atomic hydrogen exposures, as well as Si passivation depositions prior to in situ atomic layer deposition of Al2O3. As–O bonding was removed and a bond conversion process with Si deposition is observed. The accumulation capacitance frequency dispersion was removed only when a Si interlayer and a specific surface clean were combined
Nuclear energy density optimization: Shell structure
Nuclear density functional theory is the only microscopical theory that can
be applied throughout the entire nuclear landscape. Its key ingredient is the
energy density functional. In this work, we propose a new parameterization
UNEDF2 of the Skyrme energy density functional. The functional optimization is
carried out using the POUNDerS optimization algorithm within the framework of
the Skyrme Hartree-Fock-Bogoliubov theory. Compared to the previous
parameterization UNEDF1, restrictions on the tensor term of the energy density
have been lifted, yielding a very general form of the energy density functional
up to second order in derivatives of the one-body density matrix. In order to
impose constraints on all the parameters of the functional, selected data on
single-particle splittings in spherical doubly-magic nuclei have been included
into the experimental dataset. The agreement with both bulk and spectroscopic
nuclear properties achieved by the resulting UNEDF2 parameterization is
comparable with UNEDF1. While there is a small improvement on single-particle
spectra and binding energies of closed shell nuclei, the reproduction of
fission barriers and fission isomer excitation energies has degraded. As
compared to previous UNEDF parameterizations, the parameter confidence interval
for UNEDF2 is narrower. In particular, our results overlap well with those
obtained in previous systematic studies of the spin-orbit and tensor terms.
UNEDF2 can be viewed as an all-around Skyrme EDF that performs reasonably well
for both global nuclear properties and shell structure. However, after adding
new data aiming to better constrain the nuclear functional, its quality has
improved only marginally. These results suggest that the standard Skyrme energy
density has reached its limits and significant changes to the form of the
functional are needed.Comment: 18 pages, 13 figures, 12 tables; resubmitted for publication to Phys.
Rev. C after second review by refere
Spin splitting of X-related donor impurity states in an AlAs barrier
We use magnetotunneling spectroscopy to observe the spin splitting of the
ground state of an X-valley-related Si-donor impurity in an AlAs barrier. We
determine the absolute magnitude of the effective Zeeman spin splitting factors
of the impurity ground state to be g= 2.2 0.1. We also investigate
the spatial form of the electron wave function of the donor ground state, which
is anisotropic in the growth plane
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