663 research outputs found
Enhancement and Function of the Piezoelectric Effect in Polymer Nanofibers
No full text[Image: see text] The realization of intelligent, self-powered components and devices exploiting the piezoelectric effect at large scale might greatly contribute to improve our efficiency in using resources, albeit a profound redesign of the materials and architectures used in current electronic systems would be necessary. Piezoelectricity is a property of certain materials to generate an electrical bias in response to a mechanical deformation. This effect enables energy to be harvested from strain and vibration modes, and to sustain the power of actuators, transducers, and sensors in integrated networks, such as those necessary for the Internet of Thing. Polymers, combining structural flexibility with lightweight construction and ease of processing, have been largely used in this framework. In particular, the poly(vinylidene fluoride) [PVDF, (CH(2)CF(2))(n)] and its copolymers exhibit strong piezoelectric response, are biocompatibile, can endure large strains and can be easily shaped in the form of nanomaterials. Confined geometries, improving crystal orientation and enhancing piezoelectricity enable the fabrication of piezoelectric nanogenerators, which satisfy many important technological requirements, such as conformability, cheap fabrication, self-powering, and operation with low-frequency mechanical inputs (Hz scale). This account reports on piezoelectric polymer nanofibers made by electrospinning. This technique enables the formation of high-aspect-ratio filaments, such as nanowires and nanofibers, through the application of high electric fields (i.e., on the order of hundreds of kV/m) and stretching forces to a polymeric solution. The solution might be charged with functional, organic or inorganic, fillers or dopants. The solution is then fed at a controlled flow rate through a metallic spinneret or forms a bath volume, from which nanofibers are delivered. Fibers are then collected onto metallic surfaces, and upon a change of the collecting geometry, they can form nonwovens, controlled arrays, or isolated features. Nanofibers show unique features, which include their versatility in terms of achievable chemical composition and chemico-physical properties. In addition, electrospinning can be up-scaled for industrial production. Insight into the energy generation mechanism and how the interaction among fibers can be used to enhance the piezoelectric performance are given in this paper, followed by an overview of fiber networks as the active layer in different device geometries for sensing, monitoring, and signal recognition. The use of biodegradable polymers, both natural and synthetic, as critically important building blocks of the roadmap for next-generation piezoelectric devices, is also discussed, with some representative examples. In particular, biodegradable materials have been utilized for applications related to life science, such as the realization of active scaffolds and of electronic devices to be placed in intimate contact with living tissues and organs. Overall, these materials show many relevant properties that can be of very high importance for building next-generation, sustainable energy harvesting, self-rechargeable devices and electronic components, for use in several different fields
Supplemental Material - Making plans findable, accessible, interoperable, and reusable with data infrastructure: A search engine for constructing, analyzing, and visualizing planning documents
No full textSupplemental Material for Making plans findable, accessible, interoperable, and reusable with data infrastructure: A search engine for constructing, analyzing, and visualizing planning documents by Lindsay Poirier, Dexter Antonio, Makenna Dettmann, Tiffany Eng, Jennifer Ganata, Sujoy Ghosh, Mirthala Lopez, Ranesh Karma, Asiya Natekal and Catherine Brinkley in Environment and Planning B: Urban Analytics and City Science</p
Natural Fe-bearing aluminous bridgmanite in the Katol L6 chondrite
No full textBridgmanite, the most abundant mineral of the Earth’s lower mantle, has been reported in only a few shocked chondritic meteorites; however, the compositions of these instances differ from that expected in the terrestrial bridgmanite. Here, we report the first natural occurrence of Fe-bearing aluminous bridgmanite in shock-induced melt veins within the Katol L6 chondrite with a composition that closely matches those synthesized in high-pressure and temperature experiments over the last three decades. The Katol bridgmanite coexists with majorite and metal-sulfide intergrowths. We found that the natural Fe-bearing aluminous bridgmanite in the Katol L6 chondrite has a significantly higher Fe3+/ΣFe ratio (0.69 ± 0.08) than coexisting majorite (0.37 ± 0.10), which agrees with experimental studies. The Katol bridgmanite is arguably the closest natural analog for the bridgmanite composition expected to be present in the Earth’s lower mantle. Textural observations and comparison with laboratory experiments suggest that the Katol bridgmanite formed at pressures of ∼23 to 25 gigapascals directly from the chondritic melt generated by the shock event. Thus, the Katol L6 sample may also serve as a unique analog for crystallization of bridgmanite during the final stages of magma ocean crystallization during Earth’s formation
Investigations into Semaphorin signaling and Furin as novel effectors of coronary artery disease
No full textCoronary Artery Disease (CAD), one of the most common heart disease, is the leading cause of death in the world. One of the main causes for CAD is atherosclerosis. There have been many studies done to identify genes responsible for atherosclerotic plaques formation. Recently, Genome-wide association studies (GWAS) done by Ghosh et al. has shown a strong association between semaphorin pathway with CAD. Additionally, the protease Furin was found to be a member in 6 of the 32 replicated, CAD associated pathways. To follow up for these novel findings, present studies examined the regulation of Semaphorin pathway gene expression and the effects of Furin knock-down in RAW264.7 macrophages. CAD characterized cells were induced using human high OxLDL and Furin knock-down was carried out using siRNA. Preliminary results suggest that Semaphorin pathway could be regulated by OxLDL with decrease in NRP1 and PLXNA2 expression. Presence of OxLDL also reduced the expression of Sma and Icam1 by more than 50%. Knock-down of Furin reduced expression of IL-1B, CD86 and CD205 by more than 50%. Future studies will include measurement of protein levels for candidate gene and examine of OxLDL and Furin knock-down effect in endothelial and vascular smooth muscle cells.Doctor of Philosophy (SBS
The role of furin and matrix metalloproteinases on molecular markers of coronary artery disease
No full textCardiovascular Disease (CVD) is the third leading cause of death in Singapore for the last 4 years. CVD accounted for almost a third (29.6%) of all deaths in 2015. Heart attacks usually occur due to eruption of atherosclerotic plaque. The plaque mainly consists of atheroma (macrophages), cholesterol crystals and calcification found on base of lesions.
The CARDIoGRAM study, which combined data from several thousand genome-wide association studies, has compiled suspected genetic variants related to CVD. Further studies by Ghosh et al. using GWAS has highlighted several interconnected functional and topologically interacting molecules representing novel associations (e.g. semaphoring-regulated axonal guidance pathways) and identified genes (e.g. FYN, FURIN, etc.) likely to play critical roles in the maintenance and functioning of several of the CVD pathways.
In the present study, we have utilized THP-1 human monocytes in an attempt to recapitulate possible biochemical relationships between Furin and MMP that might take place when furin is inhibited. This study also seeks to observe changes in gene expression when furin is inhibited. Based on previous study, the genes are specifically Inflammation related and Semaphorin related genes.Bachelor of Science in Biomedical Science
Critical role of the BAF chromatin remodeling complex during murine neural crest development.
No full textThe BAF complex plays an important role in the development of a wide range of tissues by modulating gene expression programs at the chromatin level. However, its role in neural crest development has remained unclear. To determine the role of the BAF complex, we deleted BAF155/BAF170, the core subunits required for the assembly, stability, and functions of the BAF complex in neural crest cells (NCCs). Neural crest-specific deletion of BAF155/BAF170 leads to embryonic lethality due to a wide range of developmental defects including craniofacial, pharyngeal arch artery, and OFT defects. RNAseq and transcription factor enrichment analysis revealed that the BAF complex modulates the expression of multiple signaling pathway genes including Hippo and Notch, essential for the migration, proliferation, and differentiation of the NCCs. Furthermore, we demonstrated that the BAF complex is essential for the Brg1-Yap-Tead-dependent transcription of target genes in NCCs. Together, our results demonstrate an important role of the BAF complex in modulating the gene regulatory network essential for neural crest development
Changing portrayal of a woman in Bollywood cinema: special reference of movies of Vidya Balan
No full textBollywood cinema had a stereotype image of woman in its movies since the beginning. Women were loaded with the patriarchal values. There portrayal matched with the image of woman which the society had in its mind like that of Sita and Radha (Hindu goddesses). Majority of the roles were those of obedient housewives or obedient daughters.
In the last decade i.e. after 2010, in India, there are more women centric films with women in leading and meaningful roles like Highway (2004, Imtiaz Ali), No one killed Jessica (2011, Raj Kumar Gupta), Kahani (2012, Sujoy Ghosh), Mardani (2014, Pradeep Sarkar, Pink (2016, Aniruddha Roy Chowdhury), Chhapaak (2020, Meghna Gulzar) Thappad (2020, Anubhav Sinha) etc. These movies also have special messages for the Indian masses, and they are helpful in bringing positive changes in the society.
This change is interactive in nature. The changing scenario has made much more space for and options for women in cinema and at same time such cinema can be a useful tool in bringing positive changes in society and that too at a fast pace. These changes as well as this interactive nature need to be properly assessed. The impact of these movies can be used for gender sensitization. Some important events that took place in India will also be summarized as they are catalyst to production of women-centric movies in India.
We will review the famous women-centric movies from that focused on representing strong women and their specific achievements. Comparative study of these movies, film reviews, interviews of stars and actors/actresses as well as various articles and books are consulted for this study. Ultimately, through my research and readings, I will conclude that Bollywood Industry has been finally successful in giving proper roles to the Indian actresses. Also, actresses like Vidya Balan have done highly commendable work that has brought glory to heroines. I chose to include Vidya Balan in this Capstone Research as she is a trendsetter when it comes to top women- centric movies in India like Kahani (2012, Sujoy Ghosh) and Dirty Picture (2011, Milan Luthria).M.A.Includes bibliographical reference
Enhanced mechanical energy harvesting ability of electrospun poly(vinylidene fluoride)/hectorite clay nanocomposites
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