ABSTRACT
A typical ground investigation for characterizing geotechnical properties of soil requires sampling soils to test in a laboratory. Laboratory X-ray computed tomography (CT) has been used to non-destructively observe soils and characterize their properties using image processing, numerical analysis, or three-dimensional (3D) printing techniques based on scanned images; however, if it becomes possible to scan the soils in the ground, it may enable the characterization without sampling them. In this study, an in-situ X-ray CT scanning system comprising a drilling machine with an integrated CT scanner was developed. A model test was conducted on gravel soil to verify if the equipment can drill and scan the soil underground. Moreover, image processing was performed on acquired 3D CT images to verify the image quality; the particle morphology (particle size and shape characteristics) was compared with the results obtained for projected particles captured in a two-dimensional (2D) manner by a digital camera. The equipment successfully drilled to a target depth of 800 mm, and the soil was scanned at depths of 700, 750, and 800 mm. Image processing results showed a reasonable agreement between the 3D and 2D particle morphology images, and confirmed the feasibility of the in-situ X-ray CT scanning system.
ABSTRACT
Manually grading D3 data visualizations is a challenging endeavor, and is especially difficult for large classes with hundreds of students. Grading an interactive visualization requires a combination of interactive, quantitative, and qualitative evaluation that are conventionally done manually and are difficult to scale up as the visualization complexity, data size, and number of students increase. We present VISGRADER, a first-of-its kind automatic grading method for D3 visualizations that scalably and precisely evaluates the data bindings, visual encodings, interactions, and design specifications used in a visualization. Our method enhances students' learning experience, enabling them to submit their code frequently and receive rapid feedback to better inform iteration and improvement to their code and visualization design. We have successfully deployed our method and auto-graded D3 submissions from more than 4000 students in a visualization course at Georgia Tech, and received positive feedback for expanding its adoption.
ABSTRACT
The latest addition to the family of Coronaviruses, SARS-CoV-2, unleashed its wrath across the globe. The outbreak has been so rapid and widespread that even the most developed countries are still struggling with ways to contain the spread of the virus. The virus began spreading from Wuhan in China in December 2019 and has currently affected more than200 countries worldwide. Nanotechnology has huge potential for killing viruses as severe as HIV, herpes, human papilloma virus, and viruses of the respiratory tract, both inside as well as outside the host. Metal-nanoparticles can be employed for biosensing methodology of viruses/bacteria, along with the development of novel drugs and vaccines for COVID-19 and future pandemics. It is thus required for the nanoparticles to be synthesized quickly along with precise control over their size distribution. In this study, we propose a simple microfluidic-reactor-platform for in-situ metal-nanoparticle synthesis to be used against the pandemic for the development of preventive, diagnostic, and antiviral drug therapies. The device has been fabricated using a customized standard photolithography process using a simple and cost-effective setup. The confirmation on standard silver and gold metal nanoparticle formation in the microfluidic reactor platform was analysed using optical fiber spectrophotometer. This novel microfluidic platform provides the advantage of in-situ synthesis, flow parameter control and reduced agglomeration of nanoparticles over the bulk synthesis due to segregation of nucleation and growth stages inside a microchannel. The results are highly reproducible and hence scaling up of the nanoparticle production is possible without involving complex instrumentation.
ABSTRACT
In recent decades, organ-on-chip devices have gained substantial interest as an alternative for studying the pathophysiological processes relevant to drug screening. Micropumps are being utilized to simulate the in vivo physiological fluid flow more realistically in these organ-on-chip devices. Micropumps play a crucial role in pumping, perfusion, and circulation of fluids in various microdevices such as on-chip PCR, DNA microarrays, miniature bioreactor cell separation, and lab-on-chip biosensing platforms. With the rapid growth in technology, efficient pumping for proper circulation of media and nutrients has become imperative. In this study, we have described the design and development of an open-source impedance micropump for continuous perfusion of nutrient medium in a liver-on-chip prototype. This micropump is controlled via an integrated microcontroller board, with an observed flow rate ranging from 0.2 to 2 mL/min. Google Sketchup 2020 and DLP 3D printing were used to fabricate small precise parts of the impedance micropump. The flow rate was measured to characterize the actuating performance of the micropump. The poly-dimethyl siloxane-based liver-on-chip prototype has been fabricated using a soft photolithography procedure. Further, a study of continuous perfusion of culture medium through the liver-on-chip containing the Hepg2 cell line was successfully performed by integrating it with the impedance micropump. Hoechst staining and Alamar Blue observed cell viability to confirm the healthy cell growth inside the liver-on-chip microfluidic chip. The compactness of the overall setup allows it to fit in a Petri plate, eliminating chances of contamination while cell handling.
ABSTRACT
A novel microfluidic-device for water disinfection via diverse physiochemical effects has been demonstrated. Firstly, a microfluidic device with embedded, multiple germicidal UV-LEDs was fabricated through the innovatively modified cost-effective soft-lithography process. Further, synthesised silver nanoparticles were immobilized within its inner microchannel surface. Disinfection results proved the synergistic bactericidal effect of coated AgNPs and coupled UV-light, while a suspension of bacterial strains, were passed through the micro-device.
ABSTRACT
Originating in China during December 2019, the novel corona-virus, SARS-CoV-2, has created mayhem worldwide in a very short time. The outbreak has been so rapid and widespread that the only option to treat the patients was administering drugs already available in the market like chloroquine/hydroxychloroquine (an antimalarial drug) and remedesivir. A large number of patients have been cured but the attribution to survival by these drugs has been controversial. Till date, we do not have any specific drug or vaccine available for COVID-19 and the pandemic seems to be far from over. To handle the current challenges posed by the outbreak effectively, we need to employ innovative interdisciplinary approaches. Organ-on-chip (OOC), particularly lung-on-chip, is one such approach which combines the potential of microfluidics, cell culture and molecular biology into a single miniaturised platform. The device is realized to be capable of simulating in-vivo physiological responses of an organ. In the current study, an OOC, which is a multichannel 3D cell culture microfluidic device, is made via soft lithography technique, using polydimethylsiloxane-polymer and diverse polymeric porous/semipermeable membranes. Several polymer membranes i.e. PDMS, polyvinylidene fluoride (PVDF), nitrocellulose, polyester etc., integrated into the microdevices, were efficiently explored to realize their better cell-adhesion and viability property. We also propose for the application of a simple, smart and cost-effective lung-on-chip platform to study the SARS-CoV-2 pathogenesis in humans, drug toxicity testing and provide insights into antigen-antibody interactions. This platform will enable us to study multiple phenomena at a micro-level generating more reliable data and a better understanding of the underlying mechanisms of SARS-CoV-2 infection and pathogenesis.
ABSTRACT
BACKGROUND: Even after decades of research, cancer, by and large, remains a challenge and is one of the major causes of death worldwide. For a very long time, it was believed that cancer is simply an outcome of changes at the genetic level but today, it has become a well-established fact that both genetics and epigenetics work together resulting in the transformation of normal cells to cancerous cells. OBJECTIVE: In the present scenario, researchers are focusing on targeting epigenetic machinery. The main advantage of targeting epigenetic mechanisms is their reversibility. Thus, cells can be reprogrammed to their normal state. Graph theory is a powerful gift of mathematics which allows us to understand complex networks. METHODOLOGY: In this study, graph theory was utilized for quantitative analysis of the epigenetic network of hepato-cellular carcinoma (HCC) and subsequently finding out the important vertices in the network thus obtained. Secondly, this network was utilized to locate novel targets for hepato-cellular carcinoma epigenetic therapy. RESULTS: The vertices represent the genes involved in the epigenetic mechanism of HCC. Topological parameters like clustering coefficient, eccentricity, degree, etc. have been evaluated for the assessment of the essentiality of the node in the epigenetic network. CONCLUSION: The top ten novel epigenetic target genes involved in HCC reported in this study are cdk6, cdk4, cdkn2a, smad7, smad3, ccnd1, e2f1, sf3b1, ctnnb1, and tgfb1.