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The Global ETD Search service is a free service for researchers
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 381 to 384 of 384 (0.056 seconds)| 381 |
Reduced Burst Release of Bioactive rhBMP-2 from a Three-phase Composite ScaffoldGrant, David William 31 December 2010 (has links)
Recombinant human bone morphogenic proteins (rhBMPs) are extensively studied and employed clinically for treatment of various bone defects. Current clinical delivery vehicles suffer wasteful burst releases that mandate supra-physiological dosing driving concerns over safety and cost. It was therefore investigated whether a unique drug delivery vehicle sequestered within a composite scaffold could lower the burst release of rhBMP-2. PLGA-calcium phosphate tri-phasic composite scaffolds delivered model protein BSA with burst release of ~13% and sustained kinetics of 0.5-1.5% BSA/day up to 45 days. rhBMP-2 was delivered with zero burst release however at much lower levels, totaling 0.09% to 0.9 % release over 10 days, but had up to 6.3-fold greater bioactivity than fresh rhBMP-2 (p<0.05). In conclusion, the three-phase composite scaffold can deliver bioactive proteins with a reduced burst release and sustained secondary kinetics.
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Reduced Burst Release of Bioactive rhBMP-2 from a Three-phase Composite ScaffoldGrant, David William 31 December 2010 (has links)
Recombinant human bone morphogenic proteins (rhBMPs) are extensively studied and employed clinically for treatment of various bone defects. Current clinical delivery vehicles suffer wasteful burst releases that mandate supra-physiological dosing driving concerns over safety and cost. It was therefore investigated whether a unique drug delivery vehicle sequestered within a composite scaffold could lower the burst release of rhBMP-2. PLGA-calcium phosphate tri-phasic composite scaffolds delivered model protein BSA with burst release of ~13% and sustained kinetics of 0.5-1.5% BSA/day up to 45 days. rhBMP-2 was delivered with zero burst release however at much lower levels, totaling 0.09% to 0.9 % release over 10 days, but had up to 6.3-fold greater bioactivity than fresh rhBMP-2 (p<0.05). In conclusion, the three-phase composite scaffold can deliver bioactive proteins with a reduced burst release and sustained secondary kinetics.
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Copper Oxide Films Grown by Atomic Layer Deposition from Bis(tri-n-butylphosphane)copper(I)acetylacetonate on Ta, TaN, Ru, and SiO2Waechtler, Thomas, Oswald, Steffen, Roth, Nina, Jakob, Alexander, Lang, Heinrich, Ecke, Ramona, Schulz, Stefan E., Gessner, Thomas, Moskvinova, Anastasia, Schulze, Steffen, Hietschold, Michael 02 May 2009 (has links)
The thermal atomic layer deposition (ALD) of
copper oxide films from the non-fluorinated yet
liquid precursor
bis(tri-<it>n</it>-butylphosphane)copper(I)acetylacetonate,
[(<sup><it>n</it></sup>Bu<sub>3</sub>P)<sub>2</sub>Cu(acac)],
and wet O<sub>2</sub> on Ta, TaN, Ru and SiO<sub>2</sub>
substrates at temperatures of < 160°C is
reported. Typical temperature-independent
growth was observed at least up to 125°C with
a growth-per-cycle of ~ 0.1 Å for the metallic
substrates and an ALD window extending down to
100°C for Ru. On SiO<sub>2</sub> and TaN the ALD window
was observed between 110 and 125°C, with
saturated growth shown on TaN still at 135°C.
Precursor self-decomposition in a chemical
vapor deposition mode led to bi-modal growth
on Ta, resulting in the parallel formation of
continuous films and isolated clusters. This
effect was not observed on TaN up to about
130°C and neither on Ru or SiO<sub>2</sub> for any
processing temperature. The degree of
nitridation of the tantalum nitride underlayers
considerably influenced the film growth. With
excellent adhesion of the ALD films on all
substrates studied, the results are a promising
basis for Cu seed layer ALD applicable to
electrochemical Cu metallization in interconnects
of ultralarge-scale integrated circuits.<br>
© 2009 The Electrochemical Society. All rights reserved. <br> / Es wird die thermische Atomlagenabscheidung
(ALD) von Kupferoxidschichten, ausgehend von
der unfluorierten, flüssigen Vorstufenverbindung
Bis(tri-<it>n</it>-butylphosphan)kupfer(I)acetylacetonat,
[(<sup><it>n</it></sup>Bu<sub>3</sub>P)<sub>2</sub>Cu(acac)],
sowie feuchtem Sauerstoff,
auf Ta-, TaN-, Ru- und SiO<sub>2</sub>-Substraten bei
Temperaturen < 160°C berichtet. Typisches
temperaturunabhängiges Wachstum wurde zumindest
bis 125°C beobachtet.
Damit verbunden wurde für
die metallischen Substrate ein Zyklenwachstum
von ca. 0.1 Å erzielt sowie ein ALD-Fenster,
das für Ru bis zu einer Temperatur von 100°C
reicht. Auf SiO<sub>2</sub> und TaN wurde das
ALD-Fenster
zwischen 110 und 125°C beobachtet, wobei auch
bei 135°C noch gesättigtes Wachstum auf TaN
gezeigt werden konnte. Die selbständige
Zersetzung des Precursors ähnlich der chemischen
Gasphasenabscheidung führte zu einem bimodalen
Schichtwachstum auf Ta, wodurch gleichzeitig
geschlossene Schichten und voneinander isolierte
Cluster gebildet wurden. Dieser Effekt wurde auf
TaN bis zu einer Temperatur von 130°C nicht
beobachtet. Ebensowenig trat er im untersuchten
Temperaturbereich auf Ru oder SiO<sub>2</sub> auf. Der
Nitrierungsgrad der TaN-Schichten beeinflusste
hierbei das Schichtwachstum stark. Mit einer
sehr guten Haftung der ALD-Schichten auf allen
untersuchten Substratmaterialien erscheinen die
Ergebnisse vielversprechend für die ALD von
Kupferstartschichten, die für die
elektrochemische Kupfermetallisierung in
Leitbahnsystemen ultrahochintegrierter
Schaltkreise anwendbar sind.
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Constructing and Commissioning HELIOS – A High Harmonic Generation Source for Pump-Probe Measurements with sub 50 fs Temporal Resolution : The Development of Experimental Equipment for Extreme Ultraviolet SpectroscopyTerschlüsen, Joachim A. January 2016 (has links)
This thesis presents HELIOS, an in-house laboratory for time-resolved pump-probe spectroscopy with extreme-ultraviolet (XUV) probe radiation. A wide span of pump wavelengths can be generated using commercial laser equipment while XUV probe radiation is generated via a high harmonic generation process in a noble gas delivering probe photons with energies between 20 eV and 72 eV. The XUV beam path features a time-preserving monochromator and was constructed and built in-house. HELIOS features an overall time resolution of about 50 fs when using 800 nm pump and 41 eV probe photons. An energy resolution of 110 meV at 41 eV photon energy can be achieved. HELIOS features two beamlines. One µ-focus beamline with an XUV focal size of about 20 µm can be used with experiments that require such a small XUV focal size as well as with different end stations. The other beamline features a semi-permanently mounted end station for angle-resolved photoelectron spectroscopy under ultra-high vacuum conditions. Experiments demonstrating the usability of HELIOS and the two beamlines are presented. A pump-probe measurement on graphene demonstrates the capability of determining a large part of the k-space in only one measurement due to the use of an ARTOF angle-resolved time-of-flight electron spectrometer. A non-angle-resolved pump-probe measurement on the conducting polymer PCPDTBT demonstrates the high signal-to-noise ratio achievable at this beamline in non-angle-resolved photoelectron-spectroscopy pump-probe measurements. The usability of the µ-focus beamline is demonstrated with time-resolved measurements on magnetic samples employing an in-house-designed spectrometer. These experiments allow the retrieval of element-specific information on the magnetization within a sample employing the transversal magneto-optical Kerr effect (T-MOKE). Additionally, a Fourier transform spectrometer for the XUV is presented, the concept was tested at a synchrotron and it was used to determine the longitudinal coherence of the XUV radiation at HELIOS.
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