scholarly journals Nitrogen Accumulation in Oyster (Crassostrea gigas) Slurry Exposed to Virucidal Cold Atmospheric Plasma Treatment

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1333
Author(s):  
Isabella Csadek ◽  
Peter Paulsen ◽  
Pia Weidinger ◽  
Kathrine H. Bak ◽  
Susanne Bauer ◽  
...  

Viral contamination of edible bivalves is a major food safety issue. We studied the virucidal effect of a cold atmospheric plasma (CAP) source on two virologically different surrogate viruses [a double-stranded DNA virus (Equid alphaherpesvirus 1, EHV-1), and a single-stranded RNA virus (Bovine coronavirus, BCoV)] suspended in Dulbecco’s Modified Eagle’s Medium (DMEM). A 15 min exposure effectuated a statistically significant immediate reduction in intact BCoV viruses by 2.8 (ozone-dominated plasma, “low power”) or 2.3 log cycles (nitrate-dominated, “high power”) of the initial viral load. The immediate effect of CAP on EHV-1 was less pronounced, with “low power” CAP yielding a 1.4 and “high power” a 1.0 log reduction. We observed a decline in glucose contents in DMEM, which was most probably caused by a Maillard reaction with the amino acids in DMEM. With respect to the application of the virucidal CAP treatment in oyster production, we investigated whether salt water could be sanitized. CAP treatment entailed a significant decline in pH, below the limits acceptable for holding oysters. In oyster slurry (a surrogate for live oysters), CAP exposure resulted in an increase in total nitrogen, and, to a lower extent, in nitrate and nitrite; this was most probably caused by absorption of nitrate from the plasma gas cloud. We could not observe a change in colour, indicative for binding of NOx to haemocyanin, although this would be a reasonable assumption. Further studies are necessary to explore in which form this additional nitrogen is deposited in oyster flesh.

2021 ◽  
Vol 105 (5) ◽  
pp. 2057-2070
Author(s):  
Bouke Boekema ◽  
Matthea Stoop ◽  
Marcel Vlig ◽  
Jos van Liempt ◽  
Ana Sobota ◽  
...  

Abstract Cold atmospheric plasma (CAP) devices generate an ionized gas with highly reactive species and electric fields at ambient air pressure and temperature. A flexible dielectric barrier discharge (DBD) was developed as an alternative antimicrobial treatment for chronic wounds. Treatment of Staphylococcus aureus in collagen-elastin matrices with CAP for 2 min resulted in a 4 log reduction. CAP treatment was less effective on S. aureus on dermal samples. CAP did not affect cellular activity or DNA integrity of human dermal samples when used for up to 2 min. Repeated daily CAP treatments for 2 min lowered cellular activity of dermal samples to 80% after 2 to 4 days, but this was not significant. Repeated treatment of ex vivo human burn wound models with CAP for 2 min did not affect re-epithelialization. Intact skin of 25 healthy volunteers was treated with CAP for 3× 20” to determine safety. Although participants reported moderate pain scores (numerical rating scale 3.3), all volunteers considered the procedure to be acceptable. Severe adverse events did not occur. CAP treatment resulted in a temporarily increased local skin temperature (≈3.4°C) and increased erythema. Lowering the plasma power resulted in a significantly lower erythema increase. Good log reduction (2.9) of bacterial load was reached in 14/15 volunteers artificially contaminated with Pseudomonas aeruginosa. This study demonstrated the in vitro and in vivo safety and efficacy in bacterial reduction of a flexible cold plasma device. Trial registration number NCT03007264, January 2, 2017 Key Points • CAP strongly reduced bacterial numbers both in vitro and in vivo. • Re-epithelialization of burn wound models was not affected by repeated CAP. • CAP treatment of intact skin was well tolerated in volunteers.


2021 ◽  
Vol 15 (5) ◽  
pp. 1656-1660
Author(s):  
Mehrdad Fojlaley ◽  
Berat Guvenc Aslan

In this research, Medwave air and surface disinfection system (model:Klin20)selected to investigation effect , towards aerosolised enveloped viruses in room air. Phi6Pseudomonas syringae phage, a surrogate for coronavirus and influenza, was used in the trials Viral suspensions of Phi6 were aerosolised within the ukas accreditation Campden BRI aerobiology laboratory to achieve initial levels of ~106PFU/m3, representing very heavily contaminated air . Air samples were taken at 15 minute intervals and analysed to determine levels of Phi6 in the room air over a total test period of 135 minutes. On 3 separate days, paired trials were carried out with the Medwave switched onand with the units witched off as a control to determine baseline levels of virus in the air overtime. Trials carried out on the first two test days showed no reduction in viral titre compared with the control. Further investigation revealed that a wiring loom within the test unit had become disconnected during transport and the instrument was therefore not functioning correctly. Results from the trial showed that the level of Phi6 in the room air decreased rapidly from an initial titre of 6.12 log PFU/m3to undetectable levels (<1.78 log PFU/m3) after 45 minutes of operation, representing a log reduction of ≥4.00 logs compared with the control run with the unit switched off. Log reductions of 2.21, 3.30and ≥4.00 logs were observed after 15, 30 and 45 minutes respective to the log PFU/m3countsin the control run Keywords: Bioaerosols nano-titanium atmospheric cold plasma, covid19


2018 ◽  
Vol 49 (1) ◽  
pp. 47-62 ◽  
Author(s):  
Petra C. Schmid

Abstract. Power facilitates goal pursuit, but how does power affect the way people respond to conflict between their multiple goals? Our results showed that higher trait power was associated with reduced experience of conflict in scenarios describing multiple goals (Study 1) and between personal goals (Study 2). Moreover, manipulated low power increased individuals’ experience of goal conflict relative to high power and a control condition (Studies 3 and 4), with the consequence that they planned to invest less into the pursuit of their goals in the future. With its focus on multiple goals and individuals’ experiences during goal pursuit rather than objective performance, the present research uses new angles to examine power effects on goal pursuit.


2018 ◽  
Vol 18 (6) ◽  
pp. 784-804 ◽  
Author(s):  
Georg Bauer

Background: Application of cold atmospheric plasma to medium generates “plasma-activated medium” that induces apoptosis selectively in tumor cells and that has an antitumor effect in vivo. The underlying mechanisms are not well understood. Objective: Elucidation of potential chemical interactions within plasma-activated medium and of reactions of medium components with specific target structures of tumor cells should allow to define the active principle in plasma activated medium. Methods: Established knowledge of intercellular apoptosis-inducing reactive oxygen/nitrogen species-dependent signaling and its control by membrane-associated catalase and SOD was reviewed. Model experiments using extracellular singlet oxygen were analyzed with respect to catalase inactivation and their relevance for the antitumor action of cold atmospheric plasma. Potential interactions of this tumor cell-specific control system with components of plasma-activated medium or its reaction products were discussed within the scope of the reviewed signaling principles. Results: None of the long-lived species found in plasma-activated medium, such as nitrite and H2O2, nor OCl- or .NO seemed to have the potential to interfere with catalase-dependent control of apoptosis-inducing signaling of tumor cells when acting alone. However, the combination of H2O2 and nitrite might generate peroxynitrite. The protonation of peroxnitrite to peroxynitrous acid allows for the generation of hydroxyl radicals that react with H2O2, leading to the formation of hydroperoxide radicals. These allow for singlet oxygen generation and inactivation of membrane-associated catalase through an autoamplificatory mechanism, followed by intercellular apoptosis-inducing signaling. Conclusion: Nitrite and H2O2 in plasma-activated medium establish singlet oxygen-dependent interference selectively with the control system of tumor cells.


2018 ◽  
Vol 18 (6) ◽  
pp. 769-775 ◽  
Author(s):  
Dayun Yan ◽  
Jonathan H. Sherman ◽  
Michael Keidar

Background: Over the past five years, the cold atmospheric plasma-activated solutions (PAS) have shown their promissing application in cancer treatment. Similar as the common direct cold plasma treatment, PAS shows a selective anti-cancer capacity in vitro and in vivo. However, different from the direct cold atmospheric plasma (CAP) treatment, PAS can be stored for a long time and can be used without dependence on a CAP device. The research on PAS is gradually becoming a hot topic in plasma medicine. Objectives: In this review, we gave a concise but comprehensive summary on key topics about PAS including the development, current status, as well as the main conclusions about the anti-cancer mechanism achieved in past years. The approaches to make strong and stable PAS are also summarized.


1993 ◽  
Vol 29 (15) ◽  
pp. 1324 ◽  
Author(s):  
L.E. Larson ◽  
M.M. Matloubian ◽  
J.J. Brown ◽  
A.S. Brown ◽  
M. Thompson ◽  
...  

1978 ◽  
Vol 42 (2) ◽  
pp. 387-394
Author(s):  
Russell Hamby

Ambiguous effects of power on attributions of moral responsibility for an accident are interpreted to result from the intervening effects of need for power, which is aroused by the anticipation of exercising power over another. 160 subjects from introductory social psychology classes participated in a questionnaire-type experiment comparing effects of high/low carelessness, severe/minor consequences, and high/low power of the attributor in a 2 × 2 × 2 factorial design. In a follow-up experiment 30 subjects were assigned to conditions of high or low power, and their needs for power and moral attributions were measured. High power seemed to arouse need for power, which was curvilinearly related to moral judgments. Those high and low in need for power attributed more moral responsibility to the perpetrator of an accident than those with moderate levels of need for power. The results suggest complicated models of both moral judgments and experimenter effects related to the level or arousal of motivations.


2021 ◽  
pp. 009164712199242
Author(s):  
Beata Zarzycka ◽  
Kamil Tomaka ◽  
Katarzyna Zając ◽  
Klaudia Marek

Ingratiation refers to acts of flattery, typically given by a low-power person to a high-power one, performed to gain acceptance and approval. This study investigates ingratiation in the religious setting, asking whether people feeling high levels of guilt or shame tend to manifest such ingratiating behavior toward God. The study aimed to examine the mediating role of prayer in the relationship between guilt and shame and ingratiation toward God. A total of 148 respondents (80 women and 68 men) participated in the study. The Religious Ingratiation Scale, the Content of Prayer Scale, and the Guilt and Shame Proneness Scale were applied to the research. The results showed that feeling guilty increased the tendency to ingratiation toward God. Prayer was the significant mediator in this relationship. People high in guilt tend to flatter God by offering more adoration and fewer repine prayers.


Sign in / Sign up

Export Citation Format

Share Document