ABSTRACT
BACKGROUND: The efficacy of bipolar ionization in the healthcare setting has yet to be proven. A major limitation of studies sponsored by industry has been the assessment of efficiency within test chambers in which ozone levels are not adequately controlled. AIM: To assess the effectiveness of bipolar ionization against antimicrobial-resistant bacteria, fungi and human coronavirus within a controlled test chamber designed to mitigate the effect of ozone. METHODS: Bacteria- and fungi-inoculated gauze pads, and human coronavirus 229E-inoculated stainless steel plates were placed within the vicinity of the AIO-2 bipolar ionizer and left at room temperature (2 h for coronavirus and 4 h for bacteria and fungi). FINDINGS: Four hours of exposure to bipolar ionization showed a 1.23-4.76 log reduction, corresponding to a 94.2->99.9% colony-forming units/gauze reduction, in Clostridioides difficile, Klebsiella pneumoniae carbapenemase-producing K. pneumoniae, meticillin-resistant Staphylococcus aureus and multi-drug-resistant S. aureus. A 1.2 log 50% tissue culture infectious dose reduction in human coronavirus was observed after 2 h. CONCLUSION: The assessment of bipolar ionization systems merits further investigation as an infection control measure.
Subject(s)
Anti-Infective Agents , Coronavirus , Methicillin-Resistant Staphylococcus aureus , Ozone , Aspergillus , Bacteria , Humans , Saccharomyces cerevisiaeABSTRACT
The infrared spectra of 1-monopalmitin- or 1-monostearin-water systems in the gel phase were observed at room temperature. In both systems the infrared intensities of the bands parallel and perpendicular to the paraffin chain are relatively reduced and enhanced, respectively, on going from the crystalline phase to the gel phase. These spectral changes are explained in terms of the interaction among oscillating dipoles, which is sensitive to the morphology change from the three-dimensional crystalline phase to the two-dimensional lipid bilayers. The non-planar lipid bilayers are proposed for the gel phase in monopalmitin-water systems with x > or = 35 (x: wt.% water).
Subject(s)
Glycerides/chemistry , Water/chemistry , Gels , Spectrophotometry, Infrared/methodsABSTRACT
Anhydrous potassium pelargonate (KC9) undergoes four thermal transitions from room temperature to 450 degrees C. A normal mode analysis was made for the molecule in phase I at room temperature and the molecule was considered to have an all-trains conformation. With increasing temperature, partial melting of the alkyl chains occurred in phase II and complete melting was observed in phase III, as confirmed by vibrational spectra. In addition, orientational disorder of the carboxylate groups was suggested in phase II. This transition behavior of potassium pelargonate was compared with the behavior of nonane and pelargonic acid.
Subject(s)
Fatty Acids/chemistry , Hot Temperature , Models, Molecular , Molecular Conformation , Potassium , Spectrophotometry, Infrared , Spectrum Analysis, Raman , Thermodynamics , VibrationABSTRACT
The infrared spectra of 1-monolaurin-water systems, where KSCN is added as the intensity standard, were observed and the infrared intensity of the bands due to acyl groups measured relatively to that of the CN stretching. The infrared intensities of the bands parallel and perpendicular to the paraffin chains decrease and increase, respectively, on going from the crystalline 1 phase to the gel phase, confirming that these intensity changes result from the long-range interaction among oscillating dipoles. The infrared spectra with no CH2 rocking and the splitting of the CH2 rocking are also discussed with the same interaction model.
Subject(s)
Glycerides/chemistry , Laurates/chemistry , Gels , Monoglycerides , Spectrophotometry, Infrared , Surface-Active Agents/chemistry , Thiocyanates/chemistry , WaterABSTRACT
The infrared spectra for some metastable states in 1-monolaurin water systems were observed at room temperature, where the relative intensity of bands due to paraffin chains changed considerably, especially in the CH2 rockings, which disappear in some cases. It is considered that the spectral changes result from the morphology change on going from the crystal to the liquid crystal, smectic B phase, so-called gel phase, which consists of the lipid bilayers with ordered paraffin chains alternating with water layers. The model for explaining the intensity change is proposed on the basis of the interaction among oscillating dipoles.
