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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

The systemic delivery of an oncolytic adenovirus expressing decorin inhibits bone metastasis in a mouse model of human prostate cancer

In an effort to develop a new therapy for prostate cancer bone metastases, we have created Ad.dcn, a recombinant oncolytic adenovirus carrying the human decorin gene. Infection of PC-3 and DU-145, the human prostate tumor cells, with Ad.dcn or a non-replicating adenovirus Ad(E1-).dcn resulted in decorin expression; Ad.dcn produced high viral titers and cytotoxicity in human prostate tumor cells. Adenoviral-mediated decorin expression inhibited Met, the Wnt/β- catenin signaling axis, vascular endothelial growth factor A, reduced mitochondrial DNA levels, and inhibited tumor cell migration. To examine the anti-tumor response of Ad.dcn, PC-3-luc cells were inoculated in the left heart ventricle to establish bone metastases in nude mice. Ad.dcn, in conjunction with control replicating and non-replicating vectors were injected via tail vein. The real-time monitoring of mice, once a week, by bioluminescence imaging and X-ray radiography showed that Ad.dcn produced significant inhibition of skeletal metastases. Analyses of the mice at the terminal time point indicated a significant reduction in the tumor burden, osteoclast number, serum TRACP 5b levels, osteocalcin levels, hypercalcemia, inhibition of cancer cachexia, and an increase in the animal survival. Finally, based on these studies, we believe that Ad.dcn can be developed as a potential new therapy for prostate cancer bone metastasis.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography

Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 Å resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1 ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1 mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. Furthermore, this study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2017

Harnessing catalytic pumps for directional delivery of microparticles in microchambers

The directed transport of microparticles in microfluidic devices is vital for efficient bioassays and fabrication of complex microstructures. There remains, but, a need for methods to propel and steer microscopic cargo that do not require modifying these particles. By using theory and experiments, we show that catalytic surface reactions can be used to deliver microparticle cargo to specified regions in microchambers. Here reagents diffuse from a gel reservoir and react with the catalyst-coated surface. Fluid density gradients due to the spatially varying reagent concentration induce a convective flow, which carries the suspended particles until the reagents are consumed. Consequently, the cargo is deposited around a specific position on the surface. The velocity and final peak location of the cargo can be tuned independently. And by increasing the local particle concentration, highly sensitive assays can be performed efficiently and rapidly. Moreover, the process can be repeated by introducing fresh reagent into the microchamber.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Study of polyvinyl alcohol nanofibrous membrane by electrospinning as a magnetic nanoparticle delivery approach

Electrospinning technique was used to fabricate polyvinyl alcohol (PVA)-based magnetic biodegradable nanofibers. PVA solution was mixed with ferrofluid or magnetic nanoparticles (MNPs) powder and formed two individual nanofibrous membranes (PVA/ferrofluid and PVA/MNPs powder) by electrospinning. The surface morphology of the nanofibrous membrane was characterized by scanning electron microscopy and the magnetic properties were measured by vibrating sample magnetometer. Macrophages (RAW 264.7) were co-cultured with the nanofibrous membranes for 12, 24, and 48 h and exhibited good cell viability (>95%). Results showed that the PVA fibers would be degraded and the embedded Fe{sub 3}O{sub 4} nanoparticles would be released and delivered to cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Fabrication of DNA/Hydroxyapatite nanocomposites by simulated body fluid for gene delivery

The hydroxyapatite (HA) formation on the surface of DNA molecules in simulated body fluid (SBF) was examined. The osteoconductivity is estimated using SBF having ion concentrations approximately equal to those of human blood plasma. After immersion for 4 weeks in SBF at 36.5 °C, the HA crystallites possessing 1-14 micrometer in diameter grew on the surface of DNA molecules. The leaf flake-like and spherical shapes morphologies were observed through scanning electron microscopy analysis. Original peaks of both of DNA and HA were characterized by fourier transform infrared spectroscopy. The Ca/P ratio (1.1-1.5) in HA was estimated by energy dispersive X-ray analysis. After biomineralization, the calculated weight ratio of DNA/HA was 18/82 by thermogravimetry/differential thermal analysis. The molecular orbital computer simulation has been used to probe the interaction of DNA with two charge-balancing ions, CaOH{sup +} and CaH{sub 2}PO{sub 4}{sup +}. The adsorption enthalpy of the two ions on DNA having negative value was the evidence for the interface in mineralization of HA in SBF.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

High and low energy gamma beam dump designs for the gamma beam delivery system at ELI-NP

The Extreme Light Infrastructure - Nuclear Physics (ELI-NP) is under construction in Magurele, Bucharest, Romania. The facility will use two 10 PW lasers and a high intensity, narrow bandwidth gamma beam for stand-alone and combined laser-gamma experiments. The accurate estimation of particle doses and their restriction within the limits for both personel and general public is very important in the design phase of any nuclear facility. In the present work, Monte Carlo simulations are performed using FLUKA and MCNPX to design 19.4 and 4 MeV gamma beam dumps along with shielding of experimental areas. Dose rate contour plots from both FLUKA and MCNPX along with numerical values of doses in experimental area E8 of the facility are performed. The calculated doses are within the permissible limits. Furthermore, a reasonable agreement between both codes enhances our confidence in using one or both of them for future calculations in beam dump designs, radiation shielding, radioactive inventory, and other calculations releated to radiation protection. Residual dose rates and residual activity calculations are also performed for high-energy beam dump and their effect is negligible in comparison to contributions from prompt radiation.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Light-responsive polymer microcapsules as delivery systems for natural active agents

In this work we report the preparation and the release behavior of UV-responsive polymeric microcapsules containing essential oils as a core. The oil acted also as a monomer solvent during polymerization. Accordingly, the potentially toxic organic solvent traditionally used was replaced with a natural active substance, resulting in a more sustainable functional system. Polymer shell was based on a lightly cross-linked polyamide containing UV-sensitive azobenzene moieties in the main chain. The micro-sized capsules were obtained via interfacial polycondensation in o/w emulsion, and their mean size was measured via Dynamic Light Scattering. Shape and morphology were analyzed through Scanning Electron and Optical Microscopy. UV-responsive behavior was evaluated via spectrofluorimetry, by assessing the release kinetics of a fluorescent probe molecule upon UV light irradiation (λ{sub max}=360 nm). The irradiated samples showed an increase in fluorescence intensity, in accordance with the increase of the probe molecule concentration in the release medium. As for the un-irradiated sample, no changes could be detected demonstrating the effectiveness of the obtained releasing system.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Design and delivery of the diamond double double bend achromat project

A major project is underway at Diamond Light Source to remove one of the 24 Double Bend Achromat (DBA) Storage Ring cells and replace it with a Double Double Bend Achromat (DDBA). In this way a new Insertion Device (ID) straight can be created and so ID light can be produced and delivered to a beamline previously only capable of receiving Bending Magnet (BM) radiation. This project is in support of the micro-focus Protein Crystallography (MX) beamline VMX-m which is scheduled to take users towards the end of 2017. This paper describes the Engineering Design of the DDBA project in more detail and gives the current status of the project.

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

A 3D-printed microbial cell culture platform with in situ PEGDA hydrogel barriers for differential substrate delivery

Additive manufacturing, or 3D-printing techniques have recently begun to enable simpler, faster, and cheaper production of millifluidic devices at resolutions approaching 100–200 μ m. At this resolution, cell culture devices can be constructed that more accurately replicate natural environments compared with conventional culturing techniques. A number of microfluidics researchers have begun incorporating additive manufacturing into their work, using 3D-printed devices in a wide array of chemical, fluidic, and even some biological applications. In this work, we describe a 3D-printed cell culture platform and demonstrate its use in culturing Pseudomonas putida KT2440 bacteria for 44 h under a differential substrate gradient. Polyethylene glycol diacrylate (PEGDA) hydrogel barriers are patterned in situ within a 3D-printed channel. Transport of the toluidine blue tracer dye through the hydrogel barriers is characterized. Nutrients and oxygen were delivered to cells in the culture region by diffusion through the PEGDA hydrogel barriers from adjacent media or saline perfusion channels. Expression of green fluorescent protein by P. putida KT2440 enabled real time visualization of cell density within the 3D-printed channel, and demonstrated cells were actively expressing protein over the course of the experiment. Cells were observed clustering near hydrogel barrier boundaries where fresh substrate and oxygen were being delivered via diffusive transport, but cells were unable to penetrate the barrier. The device described here provides a versatile and easy to implement platform for cell culture in readily controlled gradient microenvironments. By adjusting device geometry and hydrogel properties, this platform could be further customized for a wide variety of biological applications.

42 ENGINEERING↗
DOE OSTI2023

Sputter sample preparation for ion beam delivery of radium-223 at ATLAS

A radium-223 ion beam was delivered to an experiment from the electron cyclotron resonance ion source, ECR2, at the Argonne Tandem Linac Accelerator System (ATLAS). Here, the radium-223 material was in a nitrate salt form within a vial, prior to being converted to a usable sputter sample. The sputter sample was produced using a new sample preparation method, where the radium nitrate was dissolved into a solution and pipetted onto pressed aluminum powder. This sample was then allowed to dry, distributing the radium-223 material throughout the sputter sample. Ion source operation using the radium sputter sample is described with the operating parameters listed. The intensity and energy requirements for this ion beam were 1 × 10 6 particles/s and 1.07 GeV, respectively. Because the intensity is relatively low compared to most experiments at ATLAS, previously developed accelerator mass spectrometry methods were used Scott et al. to avoid the need for tuning of the low-intensity beam of interest. Handling of the radium material, as well as loading and unloading of the sputter sample from ECR2, required collaboration with Health Physics. Procedures were used and dry runs were carried out before, during, and after the experiment to ensure the safety of the workers. The processes used and lessons learned are described within.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2023

Development of spinning-disk solid sample delivery system for high-repetition rate x-ray free electron laser experiments

X-ray free-electron lasers (XFELs) deliver intense x-ray pulses that destroy the sample in a single shot by a Coulomb explosion. Experiments using XFEL pulse trains or the new generation of high-repetition rate XFELs require rapid sample replacement beyond those provided by the systems now used at low repletion-rate XFELs. We describe the development and characterization of a system based on a spinning disk to continuously deliver a solid sample into an XFEL interaction point at very high speeds. We tested our system at the Linac Coherent Light Source and European XFEL hard x-ray nano-focus instruments, employing it to deliver a 25 μm copper foil sample, which can be used as a gain medium for stimulated x-ray emission for the proposed x-ray laser oscillator.

47 OTHER INSTRUMENTATION↗