Photolithographic micropatterning of organic, flexible biomaterials and its applications

A current trend in biodevices has involved a shift from traditional rigid platforms to flexible and stretchable formats. These flexible devices are expected to have a significant impact on future healthcare, disease diagnostics and therapeutics. However, the fabrication of such flexible devices has been limited by the choice of materials. Biomimetic composites of naturally derived and synthetic polymers provide exciting opportunities to develop mechanically flexible, physiologically compliant, and degradable bioelectronic systems. Advantages include the ability to provide conformal contact at non-planar biointerfaces, being able to be degraded at controllable rate, and invoking minimal reactions within the body. These factors present great potential as implantable devices for in-vivo applications, while also addressing concerns with “electronic waste” by being intrinsically degradable. In this work, we present a combination of photo-crosslinkable silk proteins and conductive polymers to precisely fabricate flexible devices and cell culture substrate. A facile and scalable photolithography is applied to fabricate flexible substrates with conductive and non- conductive micropatterns which show tuneable electrical and mechanical properties. We also demonstrate an approach to engineer flexibility in materials through the creation of patterned defects inspired from Kirigami- the Japanese art of paper cutting. Mechanically flexible, free- standing, optically transparent, large-area biomaterial sheets with precisely defined and computationally designed microscale cuts can be formed using a single-step photolithographic process. As composites with conducting polymers, flexible, intrinsically electroactive sheets can be formed. Through this work, the possibility of making next- generation, fully organic, flexible bioelectronics is explored.https://scholarscompass.vcu.edu/gradposters/1099/thumbnail.jp

Smart Parking System

Master of ScienceDepartment of Computing and Information SciencesDaniel A. AndresenLocating a parking spot during peak hours in most populated areas like shopping malls, universities, exhibitions or convention centers is difficult for the drivers. The difficulty rises from not knowing where the available spots may be at that required time. Smart parking is a solution to metropolitan cities to reduce congestion, cut vehicle emission totals and save persons' time by helping them in finding a spot to park. Smart Parking is a parking system, usually a new one that is equipped with special structured devices (things) to detect the available parking slots at any parking area. This is an application based on Internet of Things (IoT) that in Real-Time environment have sensors and devices embedded into parking spaces, transmitting data on the occupancy status; and the vehicle drivers can search for parking availability using their mobile phones or any infotainment system that is attached to the vehicle. Hence the driver would know where there is an available spot to park his vehicle in less time, reducing the energy consumption and air pollution. The Client or the sensor posts the parking slot occupancy status to a web service URL. The Java based web service is built using Spring and Hibernate to connect to the backend system. The web service (.war) file is deployed on Apache Tomcat Server and the backend used is MySQL database

Developmental stages identified in the trophozoite of the free-living Alveolate flagellate Colpodella sp. (Apicomplexa)

In this study we performed light, immunofluorescent and transmission electron microscopy of Colpodella trophozoites to characterize trophozoite morphology and protein distribution. The use of Giemsa staining and antibodies to distinguish Colpodella life cycle stages has not been performed previously. Rhoptry and β-tubulin antibodies were used in immunofluorescent assays (IFA) to identify protein localization and distribution in the trophozoite stage of Colpodella (ATCC 50594). We report novel data identifying “doughnut-shaped” vesicles in the cytoplasm and apical end of Colpodella trophozoites reactive with antibodies specific to Plasmodium merozoite rhoptry proteins. Giemsa staining and immunofluorescent microscopy identified different developmental stages of Colpodella trophozoites, with the presence or absence of vesicles corresponding to maturity of the trophozoite. These data demonstrate for the first time evidence of rhoptry protein conservation between Plasmodium and Colpodella and provide further evidence that Colpodella trophozoites can be used as a heterologous model to investigate rhoptry biogenesis and function. Staining and antibody reactivity will facilitate phylogenetic, biochemical and molecular investigations of Colpodella sp. Developmental stages can be distinguished by Giemsa staining and antibody reactivity.Keywords: Colpodella · Rhoptries · Trichocysts · Apical complex · Plasmodium RhopH

DMLA: A Dynamic Model-Based Lambda Architecture for Learning and Recognition of Features in Big Data

Title from PDF of title page, viewed April 19, 2017Thesis advisor: Yugyung LeeVitaIncludes bibliographical references (pages 57-58)Thesis (M.S.)--School of Computing and Engineering. University of Missouri--Kansas City, 2016Real-time event modeling and recognition is one of the major research areas that is yet to reach its fullest potential. In the exploration of a system to fit in the tremendous challenges posed by data growth, several big data ecosystems have evolved. Big Data Ecosystems are currently dealing with various architectural models, each one aimed to solve a real-time problem with ease. There is an increasing demand for building a dynamic architecture using the powers of real-time and computational intelligence under a single workflow to effectively handle fast-changing business environments. To the best of our knowledge, there is no attempt at supporting a distributed machine-learning paradigm by separating learning and recognition tasks using Big Data Ecosystems. The focus of our study is to design a distributed machine learning model by evaluating the various machine-learning algorithms for event detection learning and predictive analysis with different features in audio domains. We propose an integrated architectural model, called DMLA, to handle real-time problems that can enhance the richness in the information level and at the same time reduce the overhead of dealing with diverse architectural constraints. The DMLA architecture is the variant of a Lambda Architecture that combines the power of Apache Spark, Apache Storm (Heron), and Apache Kafka to handle massive amounts of data using both streaming and batch processing techniques. The primary dimension of this study is to demonstrate how DMLA recognizes real-time, real-world events (e.g., fire alarm alerts, babies needing immediate attention, etc.) that would require a quick response by the users. Detection of contextual information and utilizing the appropriate model dynamically has been distributed among the components of the DMLA architecture. In the DMLA framework, a dynamic predictive model, learned from the training data in Spark, is loaded from the context information into a Storm topology to recognize/predict the possible events. The event-based context aware solution was designed for real-time, real-world events. The Spark based learning had the highest accuracy of over 80% among several machine-learning models and the Storm topology model achieved a recognition rate of 75% in the best performance. We verify the effectiveness of the proposed architecture is effective in real-time event-based recognition in audio domains.Introduction -- Background and related work -- Proposed framework -- Results and evaluation -- Conclusion and future wor

Effect of substrate stiffness on early human embryonic stem cell differentiation

Background: The pluripotency and self renewing properties of human embryonic stem cells (hESC) make them a valuable tool in the fields of developmental biology, pharmacology and regenerative medicine. Therefore, there exists immense interest in devising strategies for hESC propagation and differentiation. Methods involving simulation of the native stem cell microenvironment, both chemical and physical, have received a lot of attention in recent years. Equally important is evidence that cells can also sense the mechanical properties of their microenvironment. In this study, we test the hypothesis that hESCs accept mechanical cues for differentiation from the substrate by culturing them on flexible polydimethylsiloxane (PDMS) of varying stiffness. Results: PDMS substrates were prepared using available commercial formulations and characterized for stiffness, surface properties and efficiency of cell attachment and proliferation. Across different substrate stiffness, cell numbers, cell attachment and cell surface area were found to be similar. Expression of pluripotency markers decreased with increased time in culture across all PDMS substrates of varying stiffness. Analysis of gene expression of differentiation markers indicates that the differentiation process becomes less stochastic with longer culture times. Conclusions: We evaluated the utility of PDMS substrates for stem cell propagation and substrate mediated differentiation. The stiffness affected gene expression of pluripotent and differentiation markers with results indicating that these substrate systems could potentially be used to direct hESC fate towards early mesodermal lineages. This study suggests that coupled with soluble factors, PDMS substrates could potentially be useful in generating defined populations of differentiated cells.Engineering and Applied Science

Single-electron latch with granular film charge leakage suppressor

A single-electron latch is a device that can be used as a building block for Quantum-dot Cellular Automata (QCA) circuits. It consists of three nanoscale metal "dots" connected in series by tunnel junctions; charging of the dots is controlled by three electrostatic gates. One very important feature of a single-electron latch is its ability to store ("latch") information represented by the location of a single electron within the three dots. To obtain latching, the undesired leakage of charge during the retention time must be suppressed. Previously, to achieve this goal, multiple tunnel junctions were used to connect the three dots. However, this method of charge leakage suppression requires an additional compensation of the background charges affecting each parasitic dot in the array of junctions. We report a single-electron latch where a granular metal film is used to fabricate the middle dot in the latch which concurrently acts as a charge leakage suppressor. This latch has no parasitic dots, therefore the background charge compensation procedure is greatly simplified. We discuss the origins of charge leakage suppression and possible applications of granular metal dots for various single-electron circuits.Comment: 21 pages, 4 figure

Evolución del diseño de interiores en los grandes Centros Comerciales de Lima Central Sur en las últimas tres décadas

La investigación responde a una problemática que se evidencia a través de una serie de debilidades que repercuten en el diseño de dichos centros comerciales. El conocimiento de nuevas tecnologías para el diseño interior era escaso, no había conocimientos de enchapes, acabados finos, iluminación decorativa y diseño interior en general. Los materiales tampoco eran de gran ayuda, solo se conocían las estructuras comunes, como el cemento y el acero. Tampoco había conocimientos sobre técnicas constructivas

Synthetic prions generated in vitro are similar to a newly identified subpopulation of PrPSc from sporadic Creutzfeldt-Jakob disease

In recent studies, the amyloid form of recombinant prion protein (PrP) encompassing residues 89–230 (rPrP 89-230) produced in vitro induced transmissible prion disease in mice. These studies showed that unlike “classical” PrPSc produced in vivo, the amyloid fibrils generated in vitro were more proteinase-K sensitive. Here we demonstrate that the amyloid form contains a proteinase K-resistant core composed only of residues 152/153–230 and 162–230. The PK-resistant fragments of the amyloid form are similar to those observed upon PK digestion of a minor subpopulation of PrPSc recently identified in patients with sporadic Creutzfeldt-Jakob disease (CJD). Remarkably, this core is sufficient for self-propagating activity in vitro and preserves a β-sheet-rich fibrillar structure. Full-length recombinant PrP 23-230, however, generates two subpopulations of amyloid in vitro: One is similar to the minor subpopulation of PrPSc, and the other to classical PrPSc. Since no cellular factors or templates were used for generation of the amyloid fibrils in vitro, we speculate that formation of the subpopulation of PrPSc with a short PK-resistant C-terminal region reflects an intrinsic property of PrP rather than the influence of cellular environments and/or cofactors. Our work significantly increases our understanding of the biochemical nature of prion infectious agents and provides a fundamental insight into the mechanisms of prions biogenesis

Transport in Ultra-Thin Heat Pipes for Low Power Applications

Heat pipes and vapor chamber heat spreaders offer a potential solution to the increasing thermal management challenges in thin-form-factor mobile computing platforms, where efficient spreading is required to simultaneously prevent overheating of internal components and formation of hot regions on the device exterior surfaces. The operating conditions for such applications are also characterized by low input heat fluxes, which in combination with the geometric constraints, give rise to unique performance limitations that require examination. This thesis aims to characterize the steady-state and transient heat pipe performance limitations unique to such ultra-thin form factors, and characterizes the key heat transfer mechanisms governing the performance. A thermal resistance network model and a detailed two-dimensional model are used to analyze the steady-state performance of heat pipes under these conditions. A broad parametric study of geometries and heat inputs using the reduced-order model helps delineate the performance thresholds within which the effectiveness of a heat pipe is greater than that of a comparable solid heat spreader. A vapor-phase threshold unique to ultra-thin heat pipes operating at low power inputs is observed. At this threshold, the vapor-phase thermal resistance imposed by the saturation pressure/temperature gradient in the heat pipe causes a crossover in the thermal resistance, where performance becomes worse than a solid heat spreader. The higher-fidelity numerical model is used to assess the accuracy of the thermal resistance network model and to verify the validity and applicability of each assumption made regarding the transport mechanisms. Key heat transfer mechanisms not captured by the reduced-order thermal network models are identified. These include the effect of boundary conditions on the interface mass flux profile, convective effects on the vapor core temperature drop, and two-dimensional conduction on smearing of evaporation/condensation mass flux into the adiabatic section. Lastly, the numerical model was used to compare the transient performance between ultra-thin heat pipes and heat spreaders during the initial start-up period was conducted to demonstrate an initial crossover period under which the performance of the heat pipe was lower than that of a heat spreader. This thesis establishes the performance thresholds of ultra-thin form factor heat pipes operating at low input heat fluxes under steady-state operation, and identifies key performance traits that must be considered under transient operation

Integrated Physiological, Biochemical, and Molecular Analysis Identifies Important Traits and Mechanisms Associated with Differential Response of Rice Genotypes to Elevated Temperature

In changing climate, heat stress caused by high temperature poses a serious threat to rice cultivation. A multiple organizational analysis at physiological, biochemical and molecular level is required to fully understand the impact of elevated temperature in rice. This study was aimed at deciphering the elevated temperature response in eleven popular and mega rice cultivars widely grown in India. Physiological and biochemical traits specifically membrane thermostability (MTS), antioxidants, and photosynthesis were studied at vegetative and reproductive phases which were used to establish a correlation with grain yield under stress. Several useful traits in different genotypes were identified which will be important resource to develop high temperature tolerant rice cultivars. Interestingly, Nagina22 emerged as best performer in terms of yield as well as expression of physiological and biochemical traits at elevated temperature. It showed lesser relative injury, lesser reduction in chlorophyll content, increased super oxide dismutase, catalase and peroxidase activity, lesser reduction in net photosynthetic rate (PN), high transpiration rate (E) and other photosynthetic/ fluorescence parameters contributing to least reduction in spikelet fertility and grain yield at elevated temperature. Further, expression of 14 genes including heat shock transcription factors and heat shock proteins was analyzed in Nagina22 (tolerant) and Vandana (susceptible) at flowering phase, strengthening the fact that N22 performs better at molecular level also during elevated temperature. This study shows that elevated temperature response is complex and involves multiple biological processes which are needed to be characterized to address the challenges of future climate extreme conditions