4,132 research outputs found

    3D Bioprinted Structures from Cells of Non-Epithelial Mesodermal and Endodermal Lineage Using a Custom Accessible 3D Bioprinting Platform

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    Prior work within our lab has demonstrated the ability to print both murine and human mammary organoids and tumoroids in vitro that can also be reliably transplanted into a murine host for translational studies. Peripherally, this bioprinting system has also been used for 3D printing neurons, stem cells, cancer cells, and a primary cell line rich with fibroblasts, but each of these efforts were with cells of ectodermal lineage. Thus, the system\u27s capacity for use on cells of other origins had been untested. To address this, we have now developed protocols for cells of endodermal and non-epithelial mesodermal/mesenchymal lineage. In this work, we find that we can produce reliable organoids, tumoroids, and other in vitro structures from them, thus expanding the functional range of our open 3D bioprinting platform. Therefore, we demonstrate that our system is versatile for adaptation to multiple cellular systems and can be applied to the work of labs that wish to study development and pathologies in other organ systemshttps://digitalcommons.odu.edu/gradposters2022_engineering/1001/thumbnail.jp

    3D Bioprinting and Implantation of Mouse Mammary Epithelial Structures Using a Custom Accessible 3D Bioprinting Platform

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    Prior work has shown that our bioprinting system can reliably produce human mammary organoids and tumoroids with high precision. However, this was not previously applied to mouse models, which are also important with respect to translational research in cancer drug development. To address this, we have produced protocols for the development of in vitro structures from murine mammary epithelial and tumor cells. Additionally, we assessed the translatability of both human and murine bioprinted organoids into mouse mammary fat pads over a period of 6 weeks. Our lab found that our produced organoids are reliable, they can survive in vivo, and meaningfully integrate within host systems. Therefore, we have demonstrated that our system is adaptable to both human and murine models, as it offers a unique methodology for in vivo transplantation of human or murine organoids into mice, which can boost research efforts in cancer therapy research.https://digitalcommons.odu.edu/gradposters2022_engineering/1000/thumbnail.jp

    The Radial Structure of SNR N103B

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    We report on the results from a Chandra ACIS observation of the young, compact, supernova remnant N103B. The unprecedented spatial resolution of Chandra reveals sub-arcsecond structure, both in the brightness and in spectral variations. Underlying these small-scale variations is a surprisingly simple radial structure in the equivalent widths of the strong Si and S emission lines. We investigate these radial variations through spatially resolved spectroscopy using a plane-parallel, non-equilibrium ionization model with multiple components. The majority of the emission arises from components with a temperature of 1 keV: a fully ionized hydrogen component; a high ionization timescale (n_e*t > 10^12 s cm^-3) component containing Si, S, Ar, Ca, and Fe; and a low ionization timescale (n_e*t ~ 10^{11} s cm^-3) O, Ne, and Mg component. To reproduce the strong Fe Kalpha line, it is necessary to include additional Fe in a hot (> 2 keV), low ionization (n_e*t ~ 10^10.8 s cm^-3) component. This hot Fe may be in the form of hot Fe bubbles, formed in the radioactive decay of clumps of 56Ni. We find no radial variation in the ionization timescales or temperatures of the various components. Rather, the Si and S equivalent widths increase at large radii because these lines, as well as those of Ar and Ca, are formed in a shell occupying the outer half of the remnant. A shell of hot Fe is located interior to this, but there is a large region of overlap between these two shells. In the inner 30% of the remnant, there is a core of cooler, 1 keV Fe. We find that the distribution of the ejecta and the yields of the intermediate mass species are consistent with model prediction for Type Ia events.Comment: 34 pages, including 7 tables and 7 figures, Accepted by Ap

    Correlative electrochemical microscopy of Li-Ion (De)intercalation at a series of individual LiMn2 O4 particles

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    The redox activity (Li‐ion intercalation/deintercalation) of a series of individual LiMn2O4 particles of known geometry and (nano)structure, within an array, is determined using a correlative electrochemical microscopy strategy. Cyclic voltammetry (current–voltage curve, I–E) and galvanostatic charge/discharge (voltage–time curve, E–t) are applied at the single particle level, using scanning electrochemical cell microscopy (SECCM), together with co‐location scanning electron microscopy that enables the corresponding particle size, morphology, crystallinity, and other factors to be visualized. This study identifies a wide spectrum of activity of nominally similar particles and highlights how subtle changes in particle form can greatly impact electrochemical properties. SECCM is well‐suited for assessing single particles and constitutes a combinatorial method that will enable the rational design and optimization of battery electrode materials

    Scanning electrochemical cell microscopy : a versatile method for highly localised corrosion related measurements on metal surfaces

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    The development of tools that can probe corrosion related phenomena at the (sub)microscale is recognized to be increasingly important in order to understand the surface structural factors (grain orientation, inclusions etc.) that control the (electro)chemical stability (corrosion susceptibility, pitting, passivity etc.) of metal surfaces. Herein we consider the application of scanning electrochemical cell microscopy (SECCM), a relatively new member of the electrochemical droplet cell (EDC) family, for corrosion research and demonstrate the power of this technique for resolving structure and activity at the (sub)microscale. Hundreds of spatially-resolved (2â€ŻÎŒm droplet size) potentiodynamic polarization experiments have been carried out on the several hours timescale and correlated to complementary structural information from electron backscatter diffraction (EBSD) and energy dispersive x-ray spectroscopy (EDS) in order to determine the effect of grain orientation and inclusions on electrochemical processes at low carbon steel in neutral solution (10 mM KNO3). Through this approach, it has been shown unequivocally that for the low index planes, anodic currents in the passive region (an indicator of corrosion susceptibility) are greatest on (101) planes compared to (100) and (111) planes. Furthermore, individual sub-micron MnS inclusions have been probed and shown to undergo active dissolution followed by rapid repassivation. This study demonstrates the high versatility of SECCM and the considerable potential of this technique for addressing structure-activity problems in corrosion and electromaterials science

    Variability and subjectivity in the grading process for evaluating the performance of latent fingermark detection techniques

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    When assessing latent fingermark development methods, forensic researchers commonly evaluate treated samples using a grading scale. However, the subjective nature of these evaluation methods leaves the results of such investigations open to criticism for potential grader bias. Assessment of fingermark development quality is ultimately dependent on an individual's background and experience. A pilot study was conducted as a preliminary stage of a large-scale international collaboration. A set of 80 fingermark samples was developed with 1,2-indanedione-zinc chloride. Grades for photographic images of the developed fingermarks were assigned independently by 11 fingermark researchers. Sixty-seven percent of the scores given to each individual sample were the same as the median grade, and 99% of the scores were within 1 grade. The researchers were also assessed on their consistency by including 20 duplicate images to be graded. Seventy-eight percent of the grades given were identical to their original scores. These results indicate that a small group of independent fingermark graders is sufficient to produce reliable and consistent data in projects requiring the assessment of fingermark quality

    Intersectionality, Inc.: A Dialogue on Intersectionality’s Travels and Tribulations

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    In a roundtable discussion held at the American Studies Association’s annual meeting in 2013, the authors interrogate intersectionality’s uptake in diverse settings, considering how its radical potential may be coopted and conflated with “diversity,” “multiculturalism,” “inclusion,” and similarly neoliberal institutional imperatives. The authors also discuss opportunities for resistance and transformation. RĂ©sumĂ© Lors d’une table ronde tenue dans le cadre de la rĂ©union annuelle de l’American Studies Association en 2013, les auteurs s’interrogent sur l’adoption de l’intersectionnalitĂ© dans divers contextes, en considĂ©rant comment son potentiel radical peut ĂȘtre cooptĂ© et confondu avec « la diversitĂ© », « le multiculturalisme », « l’inclusion » et des impĂ©ratifs institutionnels Ă©galement nĂ©o-libĂ©raux. Les auteurs discutent Ă©galement des occasions de rĂ©sistance et de transformation

    Projections of Atmospheric Nitrogen Deposition to the Chesapeake Bay Watershed

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    Atmospheric deposition is among the largest pathways of nitrogen loading to the Chesapeake Bay Watershed (CBW). The interplay between future climate and emission changes in and around the CBW will likely shift the future nutrient deposition abundance and chemical regime (e.g., oxidized vs. reduced nitrogen). In this work, a Representative Concentration Pathway from the Community Earth System Model is dynamically downscaled using a recently updated Weather Research and Forecasting model that subsequently drives the Community Multiscale Air Quality model coupled to the agroeconomic Environmental Policy Integrated Climate model. The relative impacts of emission and climate changes on atmospheric nutrient deposition are explored for a recent historical period and a period centered on 2050. The projected regional emissions in Community Multiscale Air Quality reflect current federal and state regulations, which use baseline and projected emission years 2011 and 2040, respectively. The historical simulations of 2-m temperature (T2) and precipitation (PRECIP) have cool and dry biases, and temperature and PRECIP are projected to both increase. Ammonium wet deposition agrees well with observations, but nitrate wet deposition is underpredicted. Climate and deposition changes increase simulated future ammonium fertilizer application. In the CBW by 2050, these changes (along with widespread decreases in anthropogenic nitrogen oxide and sulfur oxide emissions, and relatively constant ammonia emissions) decrease total nitrogen deposition by 21%, decrease annual average oxidized nitrogen deposition by 44%, and increase reduced nitrogen deposition by 10%. These results emphasize the importance of decreased anthropogenic emissions on the control of future nitrogen loading to the Chesapeake Bay in a changing climate
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