Effects of Low-Frequency Electromagnetic Field on the Physicochemical Properties of Freeze-Thawed Mongolian Cheese

To verify whether a low-frequency electromagnetic field (LFE field) can help reduce structural damage during the freeze-thaw process and maintain shelf life, Mongolian cheese was frozen at -10, -20, and -30 °C, then thawed at microwave or room temperature. Results showed that LFE field-assisted frozen treatment could reduce ice crystal size and protect the protein matrix structure of cheese. Frozen-thawed cheese retained 96.5% of its hardness and showed no significant difference from the fresh one in elasticity, cohesion, and chewiness. Frozen cheese showed similar but slower ripening behavior during storage, suggesting a potential application of the LFE field in the frozen storage of high-protein foods.

Exploring the form- And time-dependent effect of low-frequency electromagnetic fields on maintenance of hippocampal long-term potentiation

Low-frequency electromagnetic field (LF-EMF) stimulation is an emerging neuromodulation tool that is attracting more attention because of its non-invasive and well-controlled characteristics. However, the effect of different LF-EMF features including the forms and the time of addition on neuronal activity has not been completely understood. In this study, we used multi-electrode array (MEA) systems to develop a flexible in vitro magnetic stimulation device with plug-and-play features that allows for real-time delivery of LF-EMFs to biological tissues. Crucially, the method enables different forms of LF-EMF to be added at any time to a long-term potentiation (LTP) experiment without interrupting the process of LTP induction. We demonstrated that the slope of field excitatory postsynaptic potentials (fEPSPs) decreased significantly under post or priming uninterrupted sine LF-EMFs. The fEPSPs slope would continue to decline significantly when LF-EMFs were added two times with a 20-min interval. Paired-pulse ratio (PPR) was analyzed and the results reflected that LF-EMFs induced LTP was expressed postsynaptically. The results of pharmacological experiments indicated that AMPA receptor activity was involved in the process of LTP loss caused by post-LF-EMFs. Moreover, the effect of priming sine or Quadripulse stimulation (QPS)-patterned LF-EMFs depended on the time interval between the end of LF-EMF and the beginning of baseline recording. Interestingly, the effect of sine LF-EMFs on LTP would not disappear within 120 min, while the impact of QPS-patterned LF-EMFs on LTP might disappear after 90 min. These results indicated that LF-EMF might have a form- and time-dependent effect on LTP.

Characterization of biofilm formation in natural water subjected to low-frequency electromagnetic fields

Electromagnetic field (EMF) treatment has proven to be effective against mineral scaling in water systems. Therefore, it should be assessed for the treatment of other deposits such as biofilms. In this study, a commercial device producing low-frequency EMF (1-10 kHz) was applied to a reactor fed with natural water for 45 days. The treatment promoted the concentration of microorganisms in suspension and limited the amount of sessile microorganisms in the biofilm, as determined by the measurement of total DNA, qPCR and microscopy. The structure of the bacterial community was assessed by t-RFLP and pyrosequencing analysis. The results showed that EMF treatment affected both planktonic and sessile community composition. EMFs were responsible for a shift in classes of Proteobacteria during development of the biofilm. It may be speculated that the EMF treatment affected particle solubility and/or microorganism hydration. This study indicated that EMFs modulated biofilm formation in natural water.