Ultrasound is widely used to disinfect drinking water and wastewater due to its strong physical and chemical effects on microorganisms. The aim of this study was to investigate the effect of ultrasound on the destruction of Mycobacterium strain 6PY1. Ultrasound waves (20 kHz or 612 kHz) were used to treat aqueous suspensions of Mycobacterium at different volumes, initial bacterial concentrations, and power densities. At the same power density and the same exposure time, sonication at high frequency resulted in a lower destruction of Mycobacterium sp. 6PY1 (35.5%) than sonication at low frequency (93%). The percentage of removal was not significantly affected by the volume of the irradiated suspension (150-300 ml) or the initial cell concentration (2.15 x 10(-3)-1.4 x 10(-2)mg protein L(-1)). At low frequency, the removal percentage of Mycobacterium sp. 6PY1 increased with increasing the power density, with a constant level reached after a certain power density. At high frequency, the removal percentage of Mycobacterium sp. 6PY1 increased with increasing the power density. The mechanism of cell killing was investigated by examining the effects of OH() radical scavengers such as sodium carbonate. At high frequency the presence of sodium carbonate suppressed the removal process. However, at low frequency the removal process was not affected, thus indicating that OH() radicals have a negligible role in this case. The latter result was supported by ten time's H(2)O(2) production at high frequency greater than that at low frequency.
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http://dx.doi.org/10.1016/j.ultsonch.2009.04.005 | DOI Listing |
Sci Rep
December 2024
Retina Ward, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
We compared chorioretinal microvascular of Slow Coronary Flow Phenomenon (SCFP) patients using Optical Coherence Tomography Angiography (OCTA) to healthy controls. We recruited 21 patients from September 2023 until January 2024 from two referral centers. We enrolled 21 age-sex-matched controls retrospectively.
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December 2024
Department of Physics, University of Liverpool, Oxford Street, Liverpool, L69 7ZE, UK.
Topological semimetals have recently garnered widespread interest in the quantum materials research community due to their symmetry-protected surface states with dissipationless transport which have potential applications in next-generation low-power electronic devices. One such material, [Formula: see text], exhibits Dirac nodal arcs and although the topological properties of single crystals have been investigated, there have been no reports in crystalline thin film geometry. We examined the growth of [Formula: see text] heterostructures on a range of single crystals by optimizing the electron beam evaporation of Pt and Sn and studied the effect of vacuum thermal annealing on phase and crystallinity.
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December 2024
Cancer Epidemiology Department, H. Lee Moffitt Cancer Center and Research Institute, 12902 Bruce B. Downs Blvd, Tampa, FL, 33612, USA.
An archetype signal dependent noise (SDN) model is a component used in analyzing images or signals acquired from different technologies. This model-component may share properties with stationary normal white noise (WN). Measurements from WN images were used as standards for making comparisons with SDN in both the image domain (ID) and Fourier domain (FD).
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December 2024
Institute of Chemical Engineering Sciences, Foundation of Research and Technology- Hellas (FORTH/ICE-HT), Stadiou Street, Platani, Patras 26504, Greece.
Due to their outstanding electrical and thermal properties, graphene and related materials have been proposed as ideal candidates for the development of lightweight systems for thermoelectric applications. Recently, the nanolaminate architecture that entails alternation of continuous graphene monolayers and ultrathin polymer films has been proposed as an efficient route for the development of composites with impressive physicochemical properties. In this work, we present a novel layer-by-layer approach for the fabrication of highly ordered, flexible, heat-resistant, and electrically conductive freestanding graphene/polymer nanolaminates through alternating Marangoni-driven self-assembly of reduced graphene oxide (rGO) and poly(ether imide) (PEI) films.
View Article and Find Full Text PDFEnviron Res
December 2024
School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318, China.
Porous carbon adsorption represents a critical component of CCUS technologies, with microporous structures playing an essential role in CO capture. The preparation of porous carbon introduces intrinsic defects, making it essential to consider both pore size and these defects for a comprehensive understanding of the CO adsorption mechanism. This study investigates the mechanisms of CO adsorption influenced by intrinsic defects and pore size using multiscale methods, incorporating experimental validation, Grand Canonical Monte Carlo simulations, and Density Functional Theory simulations.
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