Now showing items 1-20 of 933

    • 3-Dimensional spatially organized PEG-based hydrogels for an aortic valve co-culture model 

      Puperi, Daniel S.; Balaoing, Liezl R.; O'Connell, Ronan W.; West, Jennifer L.; Grande-Allen, K. Jane (2015)
      Physiologically relevant inᅠvitro models are needed to study disease progression and to develop and screen potential therapeutic interventions for disease. Heart valve disease, in particular, has no early intervention or non-invasive treatment because there is a lack of understanding the cellular mechanisms which lead to disease. Here, we establish ...
    • A 3D inᅠvitro model of patient-derived prostate cancer xenograft for controlled interrogation of inᅠvivo tumor-stromal interactions 

      Fong, Eliza L.S.; Wan, Xinhai; Yang, Jun; Morgado, Micaela; Mikos, Antonios G.; (2016)
      Patient-derived xenograft (PDX) models better represent human cancer than traditional cell lines. However, the complex in vivo environment makes it challenging to employ PDX models to investigate tumor-stromal interactions, such as those that mediate prostate cancer (PCa) bone metastasis. Thus, we engineered a defined three-dimensional (3D) hydrogel ...
    • A 3D inᅠvitro model of patient-derived prostate cancer xenograft for controlled interrogation of inᅠvivo tumor-stromal interactions 

      Fong, Eliza L.S.; Wan, Xinhai; Yang, Jun; Morgado, Micaela; Mikos, Antonios G.; (2016)
      Patient-derived xenograft (PDX) models better represent human cancer than traditional cell lines. However, the complex in vivo environment makes it challenging to employ PDX models to investigate tumor-stromal interactions, such as those that mediate prostate cancer (PCa) bone metastasis. Thus, we engineered a defined three-dimensional (3D) hydrogel ...
    • 3D Macroporous Solids from Chemically Cross-linked Carbon Nanotubes 

      (2014)
      Suzuki reaction for covalently interconnected 3D carbon nanotube (CNT) architectures is reported. The synthesis of 3D macroscopic solids made of CNTs covalently connected via Suzuki cross-coupling, a well-known carbon-carbon covalent bond forming reaction in organic chemistry, is scalable. The resulting solid has a highly porous, interconnected ...
    • A 2-D simulation study on CO2ᅠsoluble surfactant for foam enhanced oil recovery 

      Zeng, Yongchao; Farajzadeh, Rouhi; Biswal, Sibani L.; Hirasaki, George J. (2019)
      This paper probes the transport of CO2ᅠsoluble surfactant for foaming in porous media. We numerically investigate the effect of surfactant partitioning between the aqueous phase and the gaseous phase on foam transport for subsurface applications when the surfactant is injected in the CO2ᅠphase. A 2-D reservoir simulation is developed to quantify the ...
    • A Ball and Beam Module for a Haptic Paddle Education Platform 

      Rose, Chad G.; Bucki, Nathan; O’Malley, Marcia K. (2017)
      Single degree of freedom force-feedback mechatronic devices, often called haptic paddles, are used in university curriculum as well as massive open online courses (MOOCs). While devices differ based on the goals of a given course, broadly speaking they provide hands-on learning for students studying mechatronics and dynamics. We introduce the third ...
    • A Branch Decomposition Algorithm for the p-Median Problem 

      Fast, Caleb C.; Hicks, Illya V. (2017)
      In this paper, we use a branch decomposition technique to improve approximations to the p-median problem. Starting from a support graph produced either by a combination of heuristics or by linear programming, we use dynamic programming guided by a branch decomposition of that support graph to find the best p-median solution on the support graph. Our ...
    • A cable-based series elastic actuator with conduit sensor for wearable exoskeletons 

      Blumenschein, Laura H.; McDonald, Craig G.; O’Malley, Marcia K. (2017)
      There is currently a scarcity of wearable robotic devices that can practically provide physical assistance in a range of real world activities. Soft wearable exoskeletons, or exosuits, have the potential to be more portable and less restrictive than their rigid counterparts. In this paper, we present the design of an actuation system that has been ...
    • A century of Gestalt psychology in visual perception: II. Conceptual and theoretical foundations 

      Wagemans, Johan; Feldman, Jacob; Gepshtein, Sergei; Kimchi, Ruth; Pomerantz, James R.; (2012)
      Our first review article (Wagemans et al., 2012) on the occasion of the centennial anniversary of Gestalt psychology focused on perceptual grouping and figure-ground organization. It concluded that further progress requires a reconsideration of the conceptual and theoretical foundations of the Gestalt approach, which is provided here. In particular, ...
    • A Choose-Your-Own-Adventure-Style Virtual Lab Activity 

      Warning, Lauren A.; Kobylianskii, Krista (2021)
      Especially in the wake of the recent COVID-19 pandemic, which has caused universities across the globe to suspend in-person classes, online alternatives for laboratory activities are needed. Here, we report a choose-your-own-adventure (CYOA)-style activity, in which undergraduate general chemistry students influence the observed outcome of a prerecorded ...
    • A Comprehensive Set of Impact Data for Common Aerospace Metals 

      Brake, M.R.W.; Reu, P.L.; Aragon, D.S. (2017)
      The results of two sets of impact experiments are reported within. To assist with model development using the impact data reported, the materials are mechanically characterized using a series of standard experiments. The first set of impact data comes from a series of coefficient of restitution (COR) experiments, in which a 2 m long pendulum is used ...
    • A computational framework for simultaneous estimation of muscle and joint contact forces and body motion using optimization and surrogate modeling 

      Eskinazi, Ilan; Fregly, Benjamin J. (2018)
      Concurrent estimation of muscle activations, joint contact forces, and joint kinematics by means of gradient-based optimization of musculoskeletal models is hindered by computationally expensive and non-smooth joint contact and muscle wrapping algorithms. We present a framework that simultaneously speeds up computation and removes sources of ...
    • A Context-Aware Trust Framework for Resilient Distributed Cooperative Spectrum Sensing in Dynamic Settings 

      Vosoughi, Aida; Cavallaro, Joseph R.; Marshall, Alan (2017)
      Cognitive radios enable dynamic spectrum access where secondary users (SUs) are allowed to operate on the licensed spectrum bands on an opportunistic noninterference basis. Cooperation among the SUs for spectrum sensing is essential for environments with deep shadows. In this paper, we study the adverse effect of insistent spectrum sensing data ...
    • A Data-Driven Perspective on the Hierarchical Assembly of Molecular Structures 

      Boninsegna, Lorenzo; Banisch, Ralf; Clementi, Cecilia; Center for Theoretical Biological Physics (2018)
      Macromolecular systems are composed of a very large number of atomic degrees of freedom. There is strong evidence suggesting that structural changes occurring in large biomolecular systems at long time scale dynamics may be captured by models coarser than atomistic, although a suitable or optimal coarse-graining is a priori unknown. Here we propose ...
    • A general condition for the existence of unconnected equilibria for symmetric arches 

      Zhou, Yang; Stanciulescu, Ilinca (2018)
      This paper presents a semi-analytical study of unconnected equilibrium states for symmetric curved beams. Using the Fourier series approximation, a general condition for the existence of unconnected equilibria for symmetric shallow arches is derived for the first time. With this derived condition, we can directly determine whether or not a shallow ...
    • A hybrid cyt c maturation system enhances the bioelectrical performance of engineered Escherichia coli by improving the rate-limiting step 

      Su, Lin; Fukushima, Tatsuya; Ajo-Franklin, Caroline M. (2020)
      Bioelectronic devices can use electron flux to enable communication between biotic components and abiotic electrodes. We have modified Escherichia coli to electrically interact with electrodes by expressing the cytochrome c from Shewanella oneidensis MR-1. However, we observe inefficient electrical performance, which we hypothesize is due to the ...
    • A Pilot Study of Low-Cost, High-Resolution Microendoscopy as a Tool for Identifying Women with Cervical Precancer 

      Pierce, Mark C.; Guan, YaoYao; Quinn, Mary Kate; Zhang, Xun; Zhang, Wen-Hua; (2012)
      Cervical cancer remains one of the leading causes of death among women in developing countries. Without resources to support Pap smear cytology and colposcopy, cost-effective approaches which enable single-visit "see-and-treat" protocols offer the potential to reduce morbidity and mortality due to this preventable disease. We carried out a pilot ...
    • A Polynomial Blossom for the Askey–Wilson Operator 

      Simeonov, Plamen; Goldman, Ron (2018)
      We introduce a blossoming procedure for polynomials related to the Askey–Wilson operator. This new blossom is symmetric, multiaffine, and reduces to the complex representation of the polynomial on a certain diagonal. This Askey–Wilson blossom can be used to find the Askey–Wilson derivative of a polynomial of any order. We also introduce a corresponding ...
    • A promoter-level mammalian expression atlas 

      FANTOM Consortium; RIKEN PMI; CLST (DGT) (2014)
      Regulated transcription controls the diversity, developmental pathways and spatial organization of the hundreds of cell types that make up a mammal. Using single-molecule cDNA sequencing, we mapped transcription start sites (TSSs) and their usage in human and mouse primary cells, cell lines and tissues to produce a comprehensive overview of mammalian ...
    • A quantitative assessment of the model form error of friction models across different interface representations for jointed structures 

      Porter, Justin H.; Balaji, Nidish Narayanaa; Little, Clayton R.; Brake, Matthew R.W. (2022)
      Hysteretic models are widely used to model frictional interactions in joints to recreate experimental behavior. However, it is unclear which models are best suited for fitting or predicting the responses of structures. The present study evaluates 26 friction model/interface representation combinations to quantify the model form error. A Quasi-Static ...