Multifunctional Bioinstructive 3D Architectures to Modulate Cellular Behavior

Biological structures control cell behavior via physical, chemical, electrical, and mechanical cues. Approaches that allow us to build devices that mimic these cues in a combinatorial way are lacking due to there being no suitable instructive materials and limited manufacturing procedures. This challenge is addressed by developing a new conductive composite material, allowing for the fabrication of 3D biomimetic structures in a single manufacturing method based on two‐photon polymerization. The approach induces a combinatorial biostimulative input that can be tailored to a specific application. Development of the 3D architecture is performed with a chemically actuating photocurable acrylate previously identified for cardiomyocyte attachment. The material is made conductive by impregnation with multiwalled carbon nanotubes. The bioinstructive effect of 3D nano‐ and microtopography is combined with electrical stimulation, incorporating biochemical, and electromechanical cues to stimulate cells in serum‐free media. The manufactured architecture is combined with cardiomyocytes derived from human pluripotent stem cells. It is demonstrated that by mimicking biological occurring cues, cardiomyocyte behavior can be modulated. This represents a step change in the ability to manufacture 3D multifunctional biomimetic modulatory architectures. This platform technology has implications in areas spanning regenerative medicine, tissue engineering to biosensing, and may lead to more accurate models for predicting toxicity.     

Terminal reliability using binary decision diagrams

Terminal reliability has been a topic of research for the last three decades. Several techniques for determining terminal reliability are available in literature. Binary decision diagrams have attracted the attention of several digital logic research workers. The objective of this paper is to illustrate how binary decision diagrams can be exploited for determining terminal reliability of networks.     

Real-Time Control System Adopted to Energy Storage for Smart Grid Low Wind Applications: A Part of Distributed Renewables in Smart City

In this paper, extensive efforts have been undertaken to design and develop a control system, which is incorporated with an energy storage device that can store energy from low-voltage renewable sources. The developed device acts as a storage element, which can be used to charge small-scale batteries, cellular devices, and other applications in remote places where the grid connection is not available. The circuit is developed using a case-by-case analysis. In order to solve the low output voltage problem, a bipolar junction transistor-metal oxide semiconductor field-effect transistor (BJT-MOSFET) based switch control technology with the Arduino microcontroller has been implemented. The developed control system is extremely efficient in charging batteries through a supercapacitor for low-voltage sources. In this research, a small-scale 200-W portable vertical axis wind turbine is used at a wind speed of 3 m/s. The result shows the efficiency of the proposed system as compared with the conventional systems. The proposed system can be an important tool of the latest distributed energy generation technology which is an important part of a smart city. Lastly, the limitations and future scopes of the development of the control device are discussed for the future barrier. An important future scope identified is to integrate the Internet of Things based mobile interface for remote monitoring for any kind of pandemic situation like COVID-19. Now, it is high time to get our smart city concept aligned with the post COVID pandemic situation and get us prepared smartly for similar future occurrences.     

Scalable Models for Redundant Data Flow Analysis in Online Social Networks

Wireless Personal Communications - Sharing and reception of identical video contents amongst the users of various online social media applications induce enormous amount of redundant data traffic...     

Carbon nanotubes as photoacoustic molecular imaging agents in living mice

Photoacoustic imaging of living subjects offers higher spatial resolution and allows deeper tissues to be imaged compared with most optical imaging techniques. As many diseases do not exhibit a natural photoacoustic contrast, especially in their early stages, it is necessary to administer a photoacoustic contrast agent. A number of contrast agents for photoacoustic imaging have been suggested previously, but most were not shown to target a diseased site in living subjects. Here we show that single-walled carbon nanotubes conjugated with cyclic Arg-Gly-Asp (RGD) peptides can be used as a contrast agent for photoacoustic imaging of tumours. Intravenous administration of these targeted nanotubes to mice bearing tumours showed eight times greater photoacoustic signal in the tumour than mice injected with non-targeted nanotubes. These results were verified ex vivo using Raman microscopy. Photoacoustic imaging of targeted single-walled carbon nanotubes may contribute to non-invasive cancer imaging and monitoring of nanotherapeutics in living subjects.     

Trajectory sensitivity modification in optimal linear systems

A new procedure for reducing trajectory sensitivity for the optimal linear regulator is described. The design is achieved without increase in the order of optimization and without the feedback of trajectory sensitivity. The procedure is also used in the input signal design problem for linear system identification by interpreting it as increasing trajectory sensitivity with respect to parameters to be estimated.     

Development and Characterization of Palm Flower Carbon Reinforced DOPO-Urea Diamine Based Cardanol Benzoxazine-Epoxy Hybrid Composites

In the present work, amine-functionalized palm flower carbon (f-PFC)-reinforced 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-urea diamine-based cardanol benzoxazine-epoxy hybrid (DUDCBz-EP) composites have been developed and characterized. Differential scanning calorimeter analysis indicate that the amine-functionalized palm flower carbon-reinforced cardanol-benzoxazine/epoxy (f-PFC/DUDCBz-EP) hybrid composites possess the higher values of glass-transition temperature (T_g) than that of hybrid matrix (DUDCBz-EP). Results from TGA infer that the PFC reinforcement significantly improves thermal stability and char yield according to the percentage weight. Morphological studies ascertain the amorphous structure and uniform as well as homogeneous dispersion of PFC reinforcement in the hybrid matrix. Contact angle measurements indicate that both the hybrid matrix and composites developed in the present work possess hydrophobic behavior. Data obtained from corrosion studies infer that the hybrid matrix as well as hybrid composites exhibit significant corrosion-resistant behavior toward the surface of the steel specimen due to inherent characteristics of both benzoxazine and epoxy matrix, in addition to amine-functionalized PFC. The results obtained from different studies, it is suggested that these hybrid matrix possess significantly improved properties and can be exploited for high-performance cost competitive coatings for different industrial applications including protection of steel surfaces from corrosion. POLYM. ENG. SCI., 60:732–739, 2020. © 2020 Society of Plastics Engineers     

Facebook and socio-economic benefits in the developing world

Facebook is becoming increasingly important for the socio-economic development of countries across the globe as stakeholders engage in online social interaction and expand their reach for new products, services and markets to open up new revenue streams. Past studies have examined the environment that supports effective use of social networking technologies in the developed world. This study argues that the enabling environment in developed and developing countries may vary and therefore may impact Facebook adoption and its socio-economic benefits differently. The model integrates the Unified Theory of Acceptance and Use of Technology (UTAUT) and revised UTAUT. Using a structured questionnaire on a sample of 367 Facebook users, the results show that performance expectancy, effort expectancy, social influence and facilitating conditions (affordability and regulatory environment) are important factors that impact Facebook adoption in a developing country such as Malaysia. The study contributes to the literature by identifying that Facebook user's perceived socio-economic benefits act as a mediator between adoption and actual use behaviour (information seeking, socialisation, entertainment and business development). The findings also indicate that religion, ethnicity, language, gender and education are significant factors moderating the adoption-perception-use behaviour of Facebook. Theoretical and practical implications of the study are discussed in the paper.     

Necessary and sufficient conditions for S-lemma and nonconvex quadratic optimization

The celebrated S-lemma establishes a powerful equivalent condition for the nonnegativity of a quadratic function over a single quadratic inequality. However, this lemma fails without the technical condition, known as the Slater condition. In this paper, we first show that the Slater condition is indeed necessary for the S-lemma and then establishes a regularized form of the S-lemma in the absence of the Slater condition. Consequently, we present characterizations of global optimality and the Lagrangian duality for quadratic optimization problems with a single quadratic constraint. Our method of proof makes use of Brickman’s theorem and conjugate analysis, exploiting the hidden link between the convexity and the S-lemma.