http://hdl.handle.net/10453/35207 2026-05-20T21:10:46Z http://hdl.handle.net/10453/195084 Title: Prior exposure strongly influences mechanisms underpinning survival of heat shock in Escherichia coli Authors: Yasir, M; Turner, AK; Bastkowski, S; Jarvis, CS; Sweet, R; Truong, M; Charles, IG; Webber, MA Abstract: The heat shock response of i Escherichia coli /i represents a canonical example of how bacteria can recognize a stress and invoke a protective response by altering specific gene regulation. However, most understanding of the processes involved arises from experiments where cells have been subjected to immediate heat shock. In this study, we identified the populations of transposon mutants in i E. coli /i BW25113 involved in response to sudden heat shock and stepwise heat stress conditions. We used Transposon-Directed Insertion Site Sequencing with expression (TraDIS- i Xpress /i ) to identify genes whose function or expression contributed to survival under 5 different heat conditions. These conditions included direct exposure to 44 C, 47 C, or 50 C referred to as heat shock or half an hour exposure at 44 C, followed by exposure to 47 C or 50 C referred to as stepwise heat stress .A total of 530 genes were identified as contributing to one or more of the heat stress conditions tested, including known heat shock resistance genes. Only 8 genes were common to all 5 conditions, with 4 of these 8 genes being associated with energy generation. The results showed fundamentally different responses between shock and stepwise stress. In heat shock conditions, most genes conferring a fitness benefit contained an increase in insertions (loss of function) as compared to the control (37 C), while in stepwise heat stress, most genes conferring a fitness benefit had fewer insertions (representing protection of function) as compared to the control. Cell envelope genes involved in lipopolysaccharide biosynthesis ( i lpxM, lptC /i ), the Tol-Pal system ( i tolABQR-pal /i ), and outer membrane biogenesis (BAM complex) were detrimental during heat shock but essential for stepwise adaptation, while regulatory genes i relA /i (stringent response) and the i rsx /i operon (redox regulation) were specifically required for stepwise heat stress response.Prior exposure to sub-lethal heat stress 2025-01-01T00:00:00Z http://hdl.handle.net/10453/195080 Title: Spatiotemporal Variability of Atmospheric Pollutants in Syria: A Multi-Year Assessment Using Sentinel-5P Data Authors: Ayek, AAE; Zerouali, B; Srivastava, A; Loho, MA; Bailek, N; Santos, CAG Abstract: This study investigates the spatial and temporal dynamics of key air pollutants nitrogen dioxide (NO2), carbon monoxide (CO), methane (CH4), formaldehyde (HCHO), and the ultraviolet aerosol index (UVAI) over the period 2019 2024. Utilizing high-resolution remote sensing data from the Sentinel-5 Precursor satellite and its TROPOspheric Monitoring Instrument (TROPOMI) processed via Google Earth Engine (GEE), pollutant concentrations were analyzed, with spatial visualizations produced using ArcGIS Pro. The results reveal that urban and industrial hotspots notably in Damascus, Aleppo, Homs, and Hama exhibit elevated NO2 and CO levels, strongly correlated with population density, traffic, and industrial emissions. Temporal trends indicate significant pollutant fluctuations linked to external factors such as economic activities and regulatory measures. Methane concentrations have shown a steady increase, driven by intensified oil refining, biomass burning, and agricultural practices. Formaldehyde levels initially declined due to reduced industrial activity before experiencing a moderate rebound, though remaining below 2019 levels overall. The UV aerosol index demonstrated marked variability, predominantly influenced by wind-driven dust transport, desert dust storms, and localized anthropogenic emissions. These findings underscore the intricate interplay between economic dynamics and environmental processes, highlighting the critical need for robust air quality management strategies. 2025-01-01T00:00:00Z http://hdl.handle.net/10453/195077 Title: Applications of halophilic enzymes in the pharmaceutical industry and medicine Authors: Velankar, R; Shinde, V; Kothari, M; Gunjal, A Abstract: Halophiles are an important group of microorganisms that can grow under high salt conditions. The paper here describes the enzymes of halophiles and their mode of action. The application of halophiles in industries is also covered. The halophilic microorganisms have immense significance hence, this paper describes the halophilic microorganisms and their enzymes. The paper highlights mainly the enzymes, i.e., cellulase, esterase, lipase, protease, laccase, L-asparaginase, and L-glutaminase from halophiles, which have industrial applications, and the study of these enzymes is very important. http://hdl.handle.net/10453/195019 Title: A Multimode fluorescent sensor for sequential detection of Cu2+ and cysteine as well as pH sensor with real sample Applications: Extensive experimental and DFT studies. Authors: Shabbir, A; Shahzad, SA; Alzahrani, AYA; Khan, ZA; Yar, M; Rauf, W Abstract: Highly responsive and optically selective (E)-1-((4-phenoxyphenyl) diazenyl)naphthalen-2-ol) sensor PDN with aggregation induced emission enhancement (AIEE) properties has been developed for the sequential detection of Cu2+ and L- Cysteine through fluorescence On-Off-On strategy. The selectivity of sensor depends on the presence of a diazo functional group and its appropriate cavity location in sensor molecule. Azo dye-based (E)-1-((4-phenoxyphenyl) diazenyl)naphthalen-2-ol) sensor PDN has been synthesized by utilizing a simple diazotization synthetic methodology that showed extraordinary AIEE behavior with bathochromic shift owing to the formation of J-aggregates. The morphology and size of aggregates were analyzed by SEM and DLS analysis, respectively. The calculated LOD of sensor PDN for Cu2+, and L-cysteine is 0.113 nM, and 84 nM, respectively. Fluorescence, UV-visible, LC-MS, 1H and 13C NMR titration were carried out to understand the interaction of sensor with Cu2+. The sensor was practically utilized in the sequential sensing of Cu2+ and Cys in real samples. Interestingly, sensor PDN was successfully employed for the sensing of a strong acid and base as well as the detection of Cu2+ ions in the solid state. Moreover, these experimental results were supported through DFT calculations. 2025-02-15T00:00:00Z