Bacterial Inactivation by High Voltage Atmospheric Cold Plasma: Influence of Process Parameters and Effects on Cell Leakage and DNA

Aims: This study investigated a range of atmospheric cold plasma (ACP) process parameters for bacterial inactivation with further investigation of selected parameters on cell membrane integrity and DNA damage. The effects of high voltage levels, mode of exposure, gas mixture and treatment time against Escherichia coli and Listeria monocytogenes were examined. Methods and Results: 108 CFU ml-1 E. coli ATCC 25922, E. coli NCTC 12900 and L. monocytogenes NCTC11994 were ACP treated in 10ml phosphate buffered saline (PBS). Working gas mixtures used were; Air (gas mix 1), 90% N2+10% O2 (gas mix 2) and 65% O2+30% CO2+5% N2 (gas mix 3). Greater reduction of viability was observed for all strains using higher voltage of 70 kVRMS, and with working gas mixtures with higher oxygen content in combination with direct exposure. Indirect ACP exposure for 30 s inactivated below detection level both E. coli strains. L. monocytogenes inactivation within 30 s was irrespective of the mode of exposure. Leakage was assessed using A260 absorbance and DNA damage was monitored using PCR and Gel electrophoresis. Membrane integrity was compromised after 5 s, with noticeable DNA damage also dependent on the target cell after 30 s. Conclusions: Plasma treatment was effective for inactivation of challenge microorganisms, with a greater sensitivity of L. monocytogenes noted. Different damage patterns were observed for the different bacterial strains, attributed to the membrane structure and potential resistance mechanisms

Optical Emission Spectroscopy Diagnostics of Cold Plasmas for Food Sterilization

There is a growing need for economical, effective, and safe methods of sterilizing fresh produce. The most common method is a chlorine wash, which is expensive and may introduce carcinogens. High voltage cold atmospheric pressure plasmas are a promising solution that has demonstrated a germicidal effect; however, the responsible chemical mechanisms and reaction pathways are not fully understood. To elucidate this chemistry, we used optical emission spectroscopy to measure the species produced in the plasma generated by a 60 Hz pulsed dielectric barrier discharge in a plastic box containing various fill gases (He, N2, CO2, dry air, or humid air). In addition to estimating chemical species concentrations, we performed preliminary calculations of electronic, vibrational, rotational, and translational temperatures

High voltage atmospheric cold plasma decontamination of Salmonella enteritidis on chicken eggs

Salmonella enteritidis (SE) accounts for more than 70% of Salmonella spp. infections in humans with a primary source being chicken eggs, that can result from post-lay SE cross-contamination of the shell from contaminated equipment or the environment. The objective of this study was to apply a HVACP treatment that can achieve a minimum 5-log reduction in SE on the surface of artificially inoculated shell eggs with an initial bacterial load of 108 CFU/egg, after a previous disinfection. Optimized HVACP treatment conditions were an indirect treatment with air at 60% humidity at 100 kV for one minute treatment and six hours post-treatment or alternatively, five minutes of treatment and four hours post-treatment. Egg quality parameters of Haugh unit (HU), pH, color, and vitelline membrane and shell strength were tested under the optimized conditions and showed no significant difference (p > 0.05) between treated and untreated eggs. Industrial relevance: Missing information for a possible scale up of a cold plasma system for egg surface decontamination has been addressed by an optimization of HVACP treatment focused on treatment and posttreatment time, essential parameters to have into account in the food industry. These results demonstrate that HVACP is an effective decontamination method for SE on chicken shell eggs and provides a baseline for a future scale up of the process, showing that different combinations of treatment variables can achieve the desired decontamination without affecting to key quality parameters of the egg such as Haugh Unit or vitelline membrane strength.This work was supported by Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), and the Barrett Family Foundation Chair in Sustainable Food Engineering

Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks

Forward head and rounded shoulder posture (FHRSP) is theorized to contribute to alterations in scapular kinematics and muscle activity leading to the development of shoulder pain. However, reported differences in scapular kinematics and muscle activity in those with forward head and rounded shoulder posture are confounded by the presence of shoulder pain. Therefore, the purpose of this study was to compare scapular kinematics and muscle activity in individuals free from shoulder pain, with and without FHRSP. Eighty volunteers were classified as having FHRSP or ideal posture. Scapular kinematics were collected concurrently with muscle activity from the upper and lower trapezius as well as the serratus anterior muscles during a loaded flexion and overhead reaching task using an electromagnetic tracking system and surface electromyography. Separate mixed model analyses of variance were used to compare three-dimensional scapular kinematics and muscle activity during the ascending phases of both tasks. Individuals with FHRSP displayed significantly greater scapular internal rotation with less serratus anterior activity, during both tasks as well as greater scapular upward rotation, anterior tilting during the flexion task when compared with the ideal posture group. These results provide support for the clinical hypothesis that FHRSP impacts shoulder mechanics independent of shoulder pain

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Changing the IgE Binding Capacity of Tropomyosin in Shrimp through Structural Modification Induced by Cold Plasma and Glycation Treatment

Tropomyosin (TM) is the major allergen of shrimp (Penaeus chinensis). Previous studies showed that separate cold plasma or glycation have their drawback in reducing allergenicity of TM, including effectiveness and reliability. In the current study, a new processing combining cold plasma (CP) and glycation was proposed and its effect on changing IgE binding capacity of TM from shrimp was investigated. Obtained results showed the IgE binding capacity of TM was reduced by up to 40% after CP (dielectric barrier discharge, 60 kV, 1.0 A) combined with glycation treatment (4 h, 80 °C), compared with the less than 5% reduction after single CP or glycation treatment. Notably, in contrast to the general way of CP prompting glycation, this study devised a new mode of glycation with ribose after CP pretreatment. The structural changes of TM were explored to explain the decreased IgE binding reactivity. The results of multi-spectroscopies showed that the secondary and tertiary structures of TM were further destroyed after combined treatment, including the transformation of 50% α-helix to β-sheet and random coils, the modification and exposure of aromatic amino acids, and the increase of surface hydrophobicity. The morphology analysis using atomic force microscope revealed that the combined processing made the distribution of TM particles tend to disperse circularly, while it would aggregate after either processing treatment alone. These findings confirmed the unfolding and reaggregation of TM during combined processing treatment, which may result in the remarkable reduction of IgE binding ability. Therefore, the processing of CP pretreatment combined with glycation has the potential to reduce or even eliminate the allergenicity of seafood

Amyloid-β-related angiitis: a report of 2 cases with unusual presentations.

Amyloid-β-related angiitis (ABRA) is a rare complication of cerebral amyloid angiopathy in which amyloid-β deposition in the leptomeningeal and cortical vessels is associated with vasculitis characterized by transmural lymphohistiocytic, often granulomatous, inflammation. Patients usually present with acute to subacute cognitive dysfunction, headaches, and focal neurologic deficits. We report 2 cases of ABRA with unusual clinical presentations, including one case with fatal cerebral edema leading to herniation and Duret hemorrhages, and another associated with both lobar and deep parenchymal hemorrhages with intraventricular extension as well as hypercoagulability. Both showed extensive vascular amyloid-β deposition associated with granulomatous angiitis and foreign body-type multinucleated giant cells. One of our cases demonstrates the likely effects of ABRA on impairment of fluid regulation leading to severe cerebral edema, which is an uncommon manifestation of ABRA, and may be a result of impaired blood-brain barrier function or malfunction of the neurovascular unit

Amyloid-β-related angiitis: a report of 2 cases with unusual presentations.

Amyloid-β-related angiitis (ABRA) is a rare complication of cerebral amyloid angiopathy in which amyloid-β deposition in the leptomeningeal and cortical vessels is associated with vasculitis characterized by transmural lymphohistiocytic, often granulomatous, inflammation. Patients usually present with acute to subacute cognitive dysfunction, headaches, and focal neurologic deficits. We report 2 cases of ABRA with unusual clinical presentations, including one case with fatal cerebral edema leading to herniation and Duret hemorrhages, and another associated with both lobar and deep parenchymal hemorrhages with intraventricular extension as well as hypercoagulability. Both showed extensive vascular amyloid-β deposition associated with granulomatous angiitis and foreign body-type multinucleated giant cells. One of our cases demonstrates the likely effects of ABRA on impairment of fluid regulation leading to severe cerebral edema, which is an uncommon manifestation of ABRA, and may be a result of impaired blood-brain barrier function or malfunction of the neurovascular unit

In-Package Air Cold Plasma Treatment of Chicken Breast Meat: Treatment Time Effect

The objective of this study was to investigate the effects of in-package dielectric barrier discharge (DBD) atmospheric cold plasma (CP) on meat color, microbiological quality and safety of chicken breast meat (pectoralis major). Raw broiler breast meat was collected from a local commercial plant. Noninoculated meat samples and meat samples inoculated with Campylobacter and Salmonella were packed in polymeric trays with air. The packaged samples were CP-treated at 70 kV for different times (0, 60, 180, or 300 sec) and stored at 4°C for 5 days. Microbial counts (psychrophiles, Campylobacter, Salmonella) and meat color (International Commission on Illumination (CIE) L∗a∗b∗) were measured before CP treatments and after 5 days of posttreatment storage. Psychrophile growth was inhibited (P0.05) in a∗ and b∗ values between pretreatment and posttreatment plus storage; however, all CP treatments resulted in increased L∗ value (P<0.05). Results indicate that in-package CP treatments can be used to reduce both microbial spoilage and food-borne pathogen risks, which could increase microbial food safety, although it may result in an overall paler breast meat, and the reduction (about 1 log) in pathogenic and spoilage microbes are limited