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This disclosure is directed to structured compositions, including DNA-functionalized scaffolds, for drug capture, and methods and devices for sequestering chemotherapeutics from physiological fluids using the functionalized scaffolds.
The gut microbiome plays an important role in the mammalian host and when in proper balance helps protect health and prevent disease. Host environmental stress and its influence on the gut microbiome, health and disease is an emerging area of research. Exposures to unnatural light cycles are becoming increasingly common due to travel and shift work. However, much remains unknown about how these changes influence the microbiome and host health. This information is needed to understand and predict the relationship between the microbiome and host response to altered sleep cycles. In the present study, we exposed three cohorts of mice to different light cycle regimens for 12 consecutive weeks; including continuous light, continuous dark and a standard light dark regimen consisting of 12 hours light followed by 12 hours of dark. After exposure, motor and memory behavior, and the composition of the fecal microbiome and plasma metabolome were measured. Memory potential was significantly reduced in mice exposed to continuous light, whereas rotarod performance was minimally affected. The overall structure of the microbiome was relatively constant over time. However, Bacteroidales Rikenellaceae was relatively more abundant in mice exposed to continuous dark, while Bacteroidales S24-7 was relatively more abundant in mice exposed to continuous light. Several plasma metabolites, including glucose, tryptophan, pyruvate and several unidentified metabolites, were correlated to continuous dark and light exposure conditions. Specific metabolites were correlated to the abundances of specific microorganisms based on light exposure. This study provides the foundation for future studies into the mechanisms underlying the role of the gut microbiome on the murine host during light-dark stress.
An analysis is developed for obtaining transient temperatures in a two-layer semitransparent composite with spectrally dependent properties. Each external boundary of the composite is subjected to radiation and convection. The two-flux radiative transfer equations are solved by deriving a Green's function. This yields the local radiative heat source needed to numerically solve the transient energy equation. An advantage of the two-flux method is that isotropic scattering is included without added complexity. The layer refractive indices are larger than one. This produces internal reflections at the boundaries and the internal interface; the reflections are assumed diffuse. Spectral results using the Green's function method are verified by comparing with numerical solutions using the exact radiative transfer equations. Transient temperature distributions are given to illustrate the effect of radiative heating on one side of a composite with external convective cooling. The protection of a material from incident radiation is illustrated by adding scattering to the layer adjacent to the radiative source.
The phase diagram of Al-Li-Cu system in the Al-rich region was determined by means of first-principles calculations and statistical mechanics. The mixing enthalpies of many configurations for different lattices in the whole Al-Li-Cu system were determined by density functional theory simulations to find the stable phases in the convex hull. They were fitted with a cluster expansion to calculate the free energy of the configurations with different compositions as a function of temperature in the Al-rich region (Al content > 40 at.%) by means of Monte Carlo simulations. It was found that the ground state phases in the Al-rich part of the Al-Li-Cu phase diagram were α-Al, θ' (Al 2 Cu), $δ$' (Al 3 Li), $δ$ (AlLi) and T 1 (Al 6 Cu 4 Li 3 ), while θ'' (Al 3 Cu), T 1' (Al 2 CuLi) and Al 3 Cu 2 Li were found on the lowest mixing enthalpy surfaces of their lattices and were metastable. α-Al, $δ$ and T 1 are stable phases in the whole temperature range while $δ$' becomes metastable at very low temperature and θ (Al 2 Cu) replaces θ' as the stable phase at approximately 550 K due to the vibrational entropic contribution. In addition, the phase diagram in the Al-rich region was built and it was shown in isothermal sections from 100 to 900 K. They were in good agreement with the limited experimental data in the literature and provided new information regarding the stability, solubility and stoichiometry of the different phases. This information is important to understand the precipitation mechanisms during high temperature aging.
Ferritic FeCrAl-based alloys show increased oxidation resistance for accident tolerant applications as fuel cladding. This study focuses on investigating the weldability of three model FeCrAl alloys with varying alloy compositions using laser-welding techniques. A detailed study of the mechanical properties of bead-on-plate welds was used to determine the quality of welds as a function of alloy composition. Laser welding resulted in defect free welds devoid of cracking or inclusions. Initial results indicate a reduction in the yield strength of weldments compared to the base material due to distinct changes in the microstructure within the fusion zone. Although a loss of yield strength was observed, there was no significant difference in the magnitude of the tensile property changes with varying Cr or Al content. Also, there was no evidence of embrittlement; the material in the fusion zones demonstrated ductile behavior with high local ductility.
We present preliminary results from the study of ice photolysis residues which were exposed to ultraviolet (UV)/extreme UV (EUV) photon radiation. The residues were produced from the simultaneous deposition and UV irradiation of ice mixtures of astrophysical interest (H2O, CH3OH, CO, NH3, without/with N2 and/or O2, and without/with small quantities of aromatic compounds) at 15–20 K using an H2 lamp, which emits 10.2-eV (121.6 nm) Lyman-α photons and a continuum at 7.5–8 eV (155–165 nm). After warm-up to room temperature and subsequent sublimation of volatile compounds, the refractory materials (residues) recovered at room temperature were analyzed with infrared (IR) microscopy and then further irradiated with UV/EUV photons at a synchrotron facility, on a beamline providing a broad-band photon beam in the 4–45-eV range with a ~1016 photons s-1 flux.2 The residues were UV/EUV irradiated with increasing photon doses ranging from ~1018 to ~1021 photons, i.e., covering 4 orders of magnitude and relevant to those experienced by ice-coated grains in the protosolar nebula.1. After UV/EUV irradiation, residues were analyzed with IR microscopy and the data compared to those before irradiation to identify changes in chemical composition as a function of the photon dose. UV/EUV-irradiated residues were also analyzed with other techniques such as nanoscale secondary-ion mass spectrometry (nanoSIMS) to the study the changes in isotopic composition, and scanning transmission electron microscopy to look at variations in structure and C bonding distribution. Results will be compared with data from extraterrestrial materials, in particular, meteoritic insoluble organic material (IOM) and interplanetary dust particles (IDPs).
In this work, we investigate electronic transport properties of copper–graphene (Cu–G) composites using a density-functional theory (DFT) framework. Conduction in composites is studied by varying the interfacial distance of copper/graphene/copper (Cu/G/Cu) interface models. Electronic conductivity of the models computed using the Kubo–Greenwood formula shows that the conductivity increases with decreasing Cu–G distance and saturates below a threshold Cu–G distance. The DFT-based Bader charge analysis indicates increasing charge transfer between Cu atoms at the interfacial layers and the graphene with decreasing Cu–G distance. The electronic density of states reveals increasing contributions from both copper and carbon atoms near the Fermi level with decreasing Cu–G interfacial distance. By computing the space-projected conductivity of the Cu/G/Cu models, we show that the graphene forms a bridge to the electronic conduction at small Cu–G distances, thereby enhancing the conductivity.
The kinetics of pack aluminization of unalloyed nickel in packs of varying aluminum activity with various halide activators were studied. Surface compositions of the coatings as functions of time, temperature, and pack composition were obtained in order to establish the boundary conditions for diffusion in the system. The structure of the packs was also examined in order to clarify the mechanism of aluminum transport. The results indicate that the kinetics of pack aluminization are controlled jointly by gas diffusion in the pack and solid diffusion in the coating. Levine and Caves' model for gas diffusion was combined with calculations of rates of diffusion in the solid to formulate a more complete theory for the kinetics of pack aluminization.
We evaluated the effect of applying different sets of 16S rRNA primers on bacterial composition, diversity, and predicted function in chicken ceca. Cecal contents from Ross 708 birds at 1, 3, and 5 weeks of age were collected for DNA isolation. Eight different primer pairs targeting different variable regions of the 16S rRNA gene were employed. DNA sequences were analyzed using open-source platform QIIME2 and the Greengenes database. PICRUSt2 was used to determine the predicted function of bacterial communities. Changes in bacterial relative abundance due to 16S primers were determined by GLMs. The average PCR amplicon size ranged from 315 bp (V3) to 769 bp (V4–V6). Alpha- and beta-diversity, taxonomic composition, and predicted functions were significantly affected by the primer choice. Beta diversity analysis based on Unweighted UniFrac distance matrix showed separation of microbiota with four different clusters of bacterial communities. Based on the alpha- and beta-diversity and taxonomic composition, variable regions V1–V3(1) and (2), and V3–V4 and V3–V5 were in most consensus. Our data strongly suggest that selection of particular sets of the 16S rRNA primers can impact microbiota analysis and interpretation of results in chicken as was shown previously for humans and other animal species.
Here, classical molecular dynamics simulations of mixed CH 4 –CO 2 gas hydrates provide a thorough analysis of the energetics of both pure CH 4 and CO 2 hydrates and three intermediate compositions along the (CH 4 ) 1–x (CO 2 ) x ·5.75(H 2 O) solid solution. The energy is broken into guest–guest, guest–host, and host–host contributions. Radial distribution functions and three-dimensional density distributions provide insight into the changes in guest orientation and interactions with the host framework as a function of guest composition. Both energetic and structural analyses provide complementary information to previous experimental studies of the system. The experimentally observed isotropic orientation of CH 4 molecules in both small and large cages is confirmed and the description of the anisotropic orientation of CO 2 molecules in the large cage is confirmed and further enhanced. In mixed hydrates, the presence of CH 4 alters the orientation of CO 2 , an indication that the interactions between guests, either direct (guest–guest) or mediated through interactions with the host (host–guest), are an important phenomenon in these systems.
Arctic warming is causing substantial compositional, structural, and functional changes in tundra vegetation including shrub and tree-line expansion and densification. However, predicting the carbon trajectories of the changing Arctic is challenging due to interacting feedbacks between vegetation composition and structure, and surface characteristics. We conduct a sensitivity analysis of the current-date to 2100 projected surface energy fluxes, soil carbon pools, and CO 2 fluxes to different shrub expansion rates under future emission scenarios (intermediate—RCP4.5, and high—RCP8.5) using the Arctic-focused configuration of E3SM Land Model (ELM). We focus on Trail Valley Creek (TVC), an upland tundra site in the western Canadian Arctic, which is experiencing shrub densification and expansion. We find that shrub expansion did not significantly alter the modeled surface energy and water budgets. However, the carbon balance was sensitive to shrub expansion, which drove higher rates of carbon sequestration as a consequence of higher shrubification rates. Thus, at low shrub expansion rates, the site would become a carbon source, especially under RCP8.5, due to higher temperatures, which deepen the active layer and enhance soil respiration. At higher shrub expansion rates, TVC would become a net CO 2 sink under both Representative Concentration Pathway scenarios due to higher shrub productivity outweighing temperature-driven respiration increase. Our simulations highlight the effect of shrub expansion on Arctic ecosystem carbon fluxes and stocks. We predict that at TVC, shrubification rate would interact with climate change intensity to determine whether the site would become a carbon sink or source under projected future climate.
Abstract Background Diverse communities of microbial eukaryotes in the global ocean provide a variety of essential ecosystem services, from primary production and carbon flow through trophic transfer to cooperation via symbioses. Increasingly, these communities are being understood through the lens of omics tools, which enable high-throughput processing of diverse communities. Metatranscriptomics offers an understanding of near real-time gene expression in microbial eukaryotic communities, providing a window into community metabolic activity. Results Here we present a workflow for eukaryotic metatranscriptome assembly, and validate the ability of the pipeline to recapitulate real and manufactured eukaryotic community-level expression data. We also include an open-source tool for simulating environmental metatranscriptomes for testing and validation purposes. We reanalyze previously published metatranscriptomic datasets using our metatranscriptome analysis approach. Conclusion We determined that a multi-assembler approach improves eukaryotic metatranscriptome assembly based on recapitulated taxonomic and functional annotations from an in-silico mock community. The systematic validation of metatranscriptome assembly and annotation methods provided here is a necessary step to assess the fidelity of our community composition measurements and functional content assignments from eukaryotic metatranscriptomes.
Three fiber composites (graphite-fiber epoxy, graphite-fiber aluminum, and graphite-fiber magnesium) are evaluated for their possible use in space applications. Using the composite mechanics theories for thermomechanical behavior embodied in the ICAN (Integrated Composites Analyzer) computer code, select composite thermal and mechanical properties are predicted and also their response to cryogenic temperatures, resembling those which occur in space applications. The predicted results are presented in graphical form as a function of the composite's laminate configuration, fiber volume ratio and the selected use temperature. These results are suitable for preliminary design purposes only and should serve as an aid in selecting controlled experiments for obtaining corresponding measured data.
Three fiber composites (graphite-fiber epoxy, graphite-fiber aluminum, and graphite-fiber magnesium) are evaluated for their possible use in space applications. Using the composite mechanics theories for thermomechanical behavior embodied in the ICAN (Integrated Composites Analyzer) computer code, select composite thermal and mechanical properties are predicted and also their response to cryogenic temperatures, resembling those which occur in space applications. The predicted results are presented in graphical form as a function of the composite's laminate configuration, fiber volume ratio and the selected use temperature. These results are suitable for preliminary design purposes only and should serve as an aid in selecting controlled experiments for obtaining corresponding measured data.
In this paper we discuss a novel instrument, currently under development at Honeybee Robotics with SBIR funding from NASA. The device is designed to characterize elemental composition as a function of depth in non-terrestrial geological formations. The instrument consists of a miniaturized laser-induced breakdown spectrometer (LIBS) analyzer integrated in a 2" diameter drill string. While the drill provides subsurface access, the LIBS analyzer provides information on the elemental composition of the borehole wall. This instrument has a variety of space applications ranging from exploration of the Moon for which it was originally designed, to Mars, as well as a variety of terrestrial applications. Subsurface analysis is usually performed by sample acquisition through a drill or excavator, followed by sample preparation and subsequent sample presentation to an instrument or suite of instruments. An alternative approach consisting in bringing a miniaturized version of the instrument to the sample has many advantages over the traditional methodology, as it allows faster response, reduced probability of cross-contamination and a simplification in the sampling mechanisms. LIBS functions by focusing a high energy laser on a material inducing a plasma consisting of a small fraction of the material under analysis. Optical emission from the plasma, analyzed by a spectrometer, can be used to determine elemental composition. A triangulation sensor located in the sensor head determines the distance of the sensor from the borehole wall. An actuator modifies the position of the sensor accordingly, in order to compensate for changes due to the profile of the borehole walls. This is necessary because LIBS measurements are negatively affected by changes in the relative position of the focus of the laser with respect to the position of the sample (commonly referred to as the "lens to sample distance"). Profiling the borehole is done by adjusting the position of the sensor with a vertical stage; a second actuator at the top of the downhole probe allows radial scanning of the borehole. Analysis of iron and titanium in lunar simulant with LIBS was performed in air using the method of standard addition. The results for lunar simulant NU-LHT-2M show a value for the concentration of iron ranging between 2.29% and 3.05% depending on the atomic line selected. The accepted value for the sample analyzed is 2.83%, showing the capability for the system in development to provide qualitative and semi-quantitative analysis in real-time.
Global temperature increases are resulting in thaw of permafrost soil in the arctic with increased emission of greenhouse gases (GHGs). Soil microorganisms are responsible for degradation of the trapped organic carbon (C) in permafrost and emission of GHG as it thaws. However, environmental factors governing microbial degradation of soil C and GHG emissions are poorly understood. Here we determined the functional potential of soil microbiomes in arctic tundra across a cryoperturbed polygonal landscape in Barrow, Alaska. Using a combination of metagenome sequencing and gas flux measurements, we found that the soil microbiome composition, diversity and functional potential varied across the polygon transect and that specific microbes and functional genes were correlated to GHG measurements. Several draft genomes of novel species were obtained with genes encoding enzymes involved in cycling of complex organic compounds. These results have larger implications for prediction of the influence of the soil microbiome on soil C flux from arctic regions undergoing environmental change.
CO 2 adsorption energies on the (100) surfaces of a nickel oxide doped with Mg, magnesium oxide doped with Ni, and their 50:50 solid solution were calculated using density functional theory. The composition and atomic arrangement of the adsorption site was varied to understand how the local environment affects CO 2 adsorption and the basicity of the surfaces at the atomic level. The dispersive and electronic contributions to the adsorption energies were quantified, and the results indicate that the variation of the adsorption energy with adsorption site configuration and metal composition is dominated by electronic interactions. Interestingly, for magnesium oxide doped with nickel, a single substitution can create stronger CO 2 binding sites, which implies stronger basic sites, even though nickel oxide is less basic than magnesium oxide. The effect of double substitution at the binding site can be reasonably approximated by summing the effects of single substitutions. Furthermore, this work provides guidance for the preparation of metal oxides with tailored Lewis basicity.
An optimum image restoration filter is described in which provision is made to constrain the spatial extent of the restoration function, the noise level of the filter output and the rate of falloff of the composite system point-spread away from the origin. Experimental results show that sidelobes on the composite system point-spread function produce ghosts in the restored image near discontinuities in intensity level. By redetermining the filter using a penalty function that is zero over the main lobe of the composite point-spread function of the optimum filter and nonzero where the point-spread function departs from a smoothly decaying function in the sidelobe region, a great reduction in sidelobe level is obtained. Almost no loss in resolving power of the composite system results from this procedure. By iteratively carrying out the same procedure even further reductions in sidelobe level are obtained. Examples of original and iterated restoration functions are shown along with their effects on a test image.