45 KJEMI 6 2025 Jibin Antony Date: 27th of October PhD thesis: Nanostructured hybrid catalysts for photocatalytic applications Trial lecture: Plasmonic Photocatalysis: Mechanisms and Their Applications in Water Splitting Assessment Committee • First opponent: Professor Laurie King, Manchester Metropolitan University, UK • Second opponent: Professor Kaiying Wang, University of South-Eastern, Norway • Chair of the committee: Associate Professor Angelos Xomalis, Department of Electronic Systems, NTNU Supervisors • Main supervisor: Professor Magnus Rønning, Department of Chemical Engineering, NTNU • Co-supervisors: Associate Professor Jia Yang and Associate Professor Sulalit Bandyopadhyay. Both from Department of Chemical Engineering, NTNU Summary of thesis Our world faces a growing challenge: water pollution from dyes, chemicals, and other industrial waste. Cleaning this up in a sustainable way requires smart solutions. My PhD research explores how we can use sunlight - an abundant and renewable source of energy - to break down harmful pollutants in water. The idea is based on a process called photocatalysis. This means using a semiconductor material that reacts when light shines on it, breaking down harmful substances. The focus of this work is on a semiconductor material called bismutite. It can act as a photocatalyst, but like many similar materials, it usually only works under ultraviolet (UV) light. Since UV is just a small part of sunlight, it is not very practical for real-world applications. To solve this, three approaches were tested to make bismutite more effective under normal sunlight. First, bismutite was combined with silica, which helps pollutants attach more easily to the photocatalyst surface while also creating small structural defects that help speed up the breakdown of pollutants. Second, gold nanoparticles of different shapes were deposited on bismutite to investigate the effect of shape anisotropy of nanoparticles. The anisotropic nanoparticles, especially those with high aspect ratios, greatly improved the material’s ability to capture sunlight and enhanced its photocatalytic performance. Finally, a chemical treatment approach via alkali etching was tested to introduce structural defects in bismutite and improve its photocatalytic performance. Although this method alone did not result in significant improvement, it is expected to work well when combined with the other approaches. Together, these strategies showed that it is possible to improve photocatalysts so they can use sunlight more efficiently. This research adds to the growing effort of developing green technologies for cleaning water. In the long run, materials like these could be used in affordable, solar- powered systems to reduce pollution, clean wastewater, and contribute to a healthier environment. With this method, we identified 10 genes from whole lung tissue and 15 genes from airway epithelium using publicly available gene expression data from over 800 individuals. Many of these genes had not been associated with COPD before, proposing them as interesting targets for future research. Following, we extended the analysis beyond single genes to investigate altered molecular functions and regulatory mechanisms in COPD. By examining three lung sample types (whole lung tissue, airway epithelium, and bronchoalveolar lavage fluid) using pathway enrichment analyses, we found both shared and sample-type specific functions altered in COPD patients. Combining these findings with the estimated activity of gene expression regulators and existing literature, we developed a model of the hypoxia response in COPD lungs. One target gene of the key regulator HIF-1ɑ, NEK6, was consistently altered in COPD patients and correlated with reduced lung function and increased tissue damage, suggesting a possible role in COPD disease mechanisms. Finally, we focused on distinguishing COVID-19 from influenza, two viral respiratory infections with overlapping symptoms. We analyzed clinical data and extracellular vesicle (EV) surface markers in blood samples from patients with either infection, showing that several markers from both data modalities reliably differentiated between the two diseases. Notably, CD9/CD41 double-positive EVs were more common in influenza patients and were associated with thrombocyte levels, suggesting a potential role in the virulence of influenza. In summary, this thesis demonstrates how computational analysis of molecular data can reveal new targets and mechanisms in respiratory diseases. ●
RkJQdWJsaXNoZXIy MTQ3Mzgy