scholarly journals Evidence of Temporal Postdischarge Decontamination of Bacteria by Gliding Electric Discharges: Application to Hafnia alvei

2007 ◽  
Vol 73 (15) ◽  
pp. 4791-4796 ◽  
Author(s):  
Georges Kamgang-Youbi ◽  
Jean-Marie Herry ◽  
Marie-Noëlle Bellon-Fontaine ◽  
Jean-Louis Brisset ◽  
Avaly Doubla ◽  
...  
Keyword(s):  
Treatment Time ◽  
Electric Discharges ◽  
Survival Curves ◽  
Hafnia Alvei ◽  
Plasma Device ◽  
Destruction Kinetics ◽  
Unit Reduction ◽  
Log Linear ◽  
First Time ◽  
Decimal Logarithm

ABSTRACT This study aimed to characterize the bacterium-destroying properties of a gliding arc plasma device during electric discharges and also under temporal postdischarge conditions (i.e., when the discharge was switched off). This phenomenon was reported for the first time in the literature in the case of the plasma destruction of microorganisms. When cells of a model bacterium, Hafnia alvei, were exposed to electric discharges, followed or not followed by temporal postdischarges, the survival curves exhibited a shoulder and then log-linear decay. These destruction kinetics were modeled using GinaFiT, a freeware tool to assess microbial survival curves, and adjustment parameters were determined. The efficiency of postdischarge treatments was clearly affected by the discharge time (t*); both the shoulder length and the inactivation rate k max were linearly modified as a function of t*. Nevertheless, all conditions tested (t* ranging from 2 to 5 min) made it possible to achieve an abatement of at least 7 decimal logarithm units. Postdischarge treatment was also efficient against bacteria not subjected to direct discharge, and the disinfecting properties of “plasma-activated water” were dependent on the treatment time for the solution. Water treated with plasma for 2 min achieved a 3.7-decimal-logarithm-unit reduction in 20 min after application to cells, and abatement greater than 7 decimal logarithm units resulted from the same contact time with water activated with plasma for 10 min. These disinfecting properties were maintained during storage of activated water for 30 min. After that, they declined as the storage time increased.

scholarly journals Application of a roller conveyor type plasma disinfection device with fungus-contaminated citrus fruits

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Akikazu Sakudo ◽  
Yoshihito Yagyu
Keyword(s):  
Treatment Time ◽  
Citrus Fruit ◽  
Viable Cell ◽  
Cell Number ◽  
Viable Cell Number ◽  
Citrus Fruits ◽  
Decimal Reduction Time ◽  
Gas Plasma ◽  
Plasma Device ◽  
Time Required

AbstractEfficient methods to achieve the safe decontamination of agricultural products are needed. Here, we investigated the decontamination of citrus fruits to test the antifungal potential of a novel non-thermal gas plasma apparatus, termed a roller conveyer plasma instrument. This instrument generates an atmospheric pressure dielectric barrier discharge (APDBP) plasma on a set of rollers. Penicillium venetum was spotted onto the surface of the fruit or pericarps, as well as an aluminium plate to act as a control, before performing the plasma treatment. The results showed that viable cell number of P. venetum decreased with a decimal reduction time (D value or estimated treatment time required to reduce viable cell number by 90%) of 0.967 min on the aluminium plate, 2.90 min and 1.88 min on the pericarps of ‘Kiyomi’ (Citrus unshiu × C. sinensis) and ‘Kawano-natsudaidai’ (C. natsudaidai) respectively, and 2.42 min on the surface of ‘Unshu-mikan’ (C. unshiu). These findings confirmed a fungicidal effect of the plasma not only on an abiotic surface (aluminium plate) but also on a biotic surface (citrus fruit). Further development of the instrument by combining sorting systems with the plasma device promises an efficient means of disinfecting citrus fruits during food processing.

scholarly journals Tumor cytotoxicity and immunogenicity of a novel V-jet neon plasma source compared to the kINPen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lea Miebach ◽  
Eric Freund ◽  
Stefan Horn ◽  
Felix Niessner ◽  
Sanjeev Kumar Sagwal ◽  
...  
Keyword(s):  
Cell Death ◽  
Dendritic Cells ◽  
Cancer Cells ◽  
Treatment Time ◽  
Plasma Source ◽  
In Vivo Model ◽  
Antitumor Effects ◽  
Plasma Device

AbstractRecent research indicated the potential of cold physical plasma in cancer therapy. The plethora of plasma-derived reactive oxygen and nitrogen species (ROS/RNS) mediate diverse antitumor effects after eliciting oxidative stress in cancer cells. We aimed at exploiting this principle using a newly designed dual-jet neon plasma source (Vjet) to treat colorectal cancer cells. A treatment time-dependent ROS/RNS generation induced oxidation, growth retardation, and cell death within 3D tumor spheroids were found. In TUM-CAM, a semi in vivo model, the Vjet markedly reduced vascularized tumors' growth, but an increase of tumor cell immunogenicity or uptake by dendritic cells was not observed. By comparison, the argon-driven single jet kINPen, known to mediate anticancer effects in vitro, in vivo, and in patients, generated less ROS/RNS and terminal cell death in spheroids. In the TUM-CAM model, however, the kINPen was equivalently effective and induced a stronger expression of immunogenic cancer cell death (ICD) markers, leading to increased phagocytosis of kINPen but not Vjet plasma-treated tumor cells by dendritic cells. Moreover, the Vjet was characterized according to the requirements of the DIN-SPEC 91315. Our results highlight the plasma device-specific action on cancer cells for evaluating optimal discharges for plasma cancer treatment.

Are seasonal lakes as productive as permanent lakes? A case study from Ireland

2010 ◽  
Vol 67 (8) ◽  
pp. 1291-1302 ◽  
Author(s):  
Helder Cunha Pereira ◽  
Norman Allott ◽  
Catherine Coxon
Keyword(s):  
Seasonal Variation ◽  
Linear Regression ◽  
Chlorophyll A ◽  
Algal Biomass ◽  
P Limitation ◽  
Underlying Causes ◽  
Western Ireland ◽  
Log Linear ◽  
First Time

This paper compares, for the first time, nutrient levels and chlorophyll a measured in a set of seasonal lakes with those reported for permanent lakes in the literature. Twenty-two turloughs (karstic seasonal lakes) in western Ireland were sampled monthly from the onset of flooding (October) until they dried out (6 to 9 months). The turloughs showed similar levels of nutrients and chlorophyll a to those reported for Irish and international lakes. Chlorophyll a peaked between November and February in the majority of turloughs, sometimes with values higher than those measured in mesotrophic lakes in summer. A significant log-linear regression was found between total phosphorus and chlorophyll a, which suggests P limitation of algal biomass in the majority of the turloughs. The regression characteristics were not significantly different than those described in similar studies of permanent lakes. Patterns in seasonal variation of nutrients are also presented, their underlying causes being discussed in relation to their transport within catchments. Our results show that despite being predominantly winter phenomena, turloughs can be as productive as permanent lakes.

Influence of Heat Transfer with Tube Methods on Measured Thermal Inactivation Parameters for Escherichia coli

2007 ◽  
Vol 70 (4) ◽  
pp. 851-859 ◽  
Author(s):  
HYUN-JUNG CHUNG ◽  
SHAOJIN WANG ◽  
JUMING TANG
Keyword(s):  
Heat Transfer ◽  
Escherichia Coli ◽  
Heat Resistance ◽  
Bacterial Strain ◽  
Thermal Inactivation ◽  
Microbial Inactivation ◽  
Outer Diameter ◽  
Survival Curves ◽  
Log Linear ◽  
K 12

The purpose of this study was to investigate the influence of heat transfer on measured thermal inactivation kinetic parameters of bacteria in solid foods when using tube methods. The bacterial strain selected for this study, Escherichia coli K-12, had demonstrated typical first-order inactivation characteristics under isothermal test conditions. Three tubes of different sizes (3, 13, and 20 mm outer diameter) were used in the heat treatments at 57, 60, and 63°C with mashed potato as the test food. A computer model was developed to evaluate the effect of transit heat transfer behavior on microbial inactivation in the test tubes. The results confirmed that the survival curves of E. coli K-12 obtained in 3-mm capillary tubes were log linear at the three tested temperatures. The survival curves observed under nonisothermal conditions in larger tubes were no longer log linear. Slow heat transfer alone could only partially account for the large departures from log-linear behavior. Tests with the same bacterial strain after 5 min of preconditioning at a sublethal temperature of 45°C revealed significantly enhanced heat resistance. Confirmative tests revealed that the increased heat resistance of the test bacterium in the center of the large tubes during the warming-up periods resulted in significantly larger D-values than those obtained with capillary tube methods.

scholarly journals Impact of Recipient and Donor Obesity Match on the Outcomes of Liver Transplantation: All Matches Are Not Perfect

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Eliza W. Beal ◽  
Dmitry Tumin ◽  
Lanla F. Conteh ◽  
A. James Hanje ◽  
Anthony J. Michaels ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Graft Loss ◽  
Long Term Outcomes ◽  
Survival Curves ◽  
Liver Retransplantation ◽  
First Time ◽  
Transplantation Outcomes ◽  
Patient And Graft Survival ◽  
United Network

There is a paucity of literature examining recipient-donor obesity matching on liver transplantation outcomes. The United Network for Organ Sharing database was queried for first-time recipients of liver transplant whose age was ≥18 between January 2003 and September 2013. Outcomes including patient and graft survival at 30 days, 1 year, and 5 years and overall, liver retransplantation, and length of stay were compared between nonobese recipients receiving a graft from nonobese donors and obese recipient-obese donor, obese recipient-nonobese donor, and nonobese recipient-obese donor pairs. 51,556 LT recipients were identified, including 34,217 (66%) nonobese and 17,339 (34%) obese recipients. The proportions of patients receiving an allograft from an obese donor were 24% and 29%, respectively, among nonobese and obese recipients. Graft loss (HR: 1.27; 95% CI: 1.09–1.46;p=0.002) and mortality (HR: 1.38; 95% CI: 1.16–1.65;p<0.001) at 30 days were increased in the obese recipient-obese donor pair. However, 1-year graft (HR: 0.83; 95% CI: 0.74–0.93;p=0.002) and patient (HR: 0.84; 95% CI: 0.74–0.95;p=0.007) survival and overall patient (HR: 0.93; 95% CI: 0.86–1.00;p=0.042) survival were favorable. There is evidence of recipient and donor obesity disadvantage early, but survival curves demonstrate improved long-term outcomes. It is important to consider obesity in the donor-recipient match.

Thermal Inactivation of Campylobacter jejuni in Broth

2012 ◽  
Vol 75 (6) ◽  
pp. 1029-1035 ◽  
Author(s):  
ALI AL SAKKAF ◽  
GEOFF JONES
Keyword(s):  
New Zealand ◽  
The Netherlands ◽  
Campylobacter Jejuni ◽  
Thermal Inactivation ◽  
Nonlinear Models ◽  
Data Sets ◽  
Order Kinetic ◽  
Survival Curves ◽  
First Order ◽  
Log Linear

New Zealand has a high rate of reported campylobacteriosis compared with other developed countries. One possible reason is that local strains have greater heat tolerance and thus are better able to survive undercooking; this hypothesis is supported by the remarkably high D-values reported for Campylobacter jejuni in The Netherlands. The objective of this study was to investigate the thermal inactivation of isolates from New Zealand in broth, using strains that are commonly found in human cases and food samples in New Zealand. Typed Campylobacter strains were heated to a predetermined temperature using a submerged-coil heating apparatus. The first-order kinetic model has been used extensively in the calculation of the thermal inactivation parameters, D and z; however, nonlinear survival curves have been reported, and a number of models have been proposed to describe the patterns observed. Therefore, this study compared the conventional first-order model with eight nonlinear models for survival curves. Kinetic parameters were estimated using both one- and two-step regression techniques. In general, nonlinear models fit the individual inactivation data sets better than the log-linear model. However, the log-linear and the (nonlinear) Weibull models were the only models that could be successfully fitted to all data sets. For seven relevant New Zealand C. jejuni strains, at temperatures from 51.5 to 60°C, D- and z-values were obtained, ranging from 1.5 to 228 s and 4 to 5.2°C, respectively. These values are in broad agreement with published international data and do not indicate that the studied New Zealand C. jejuni strains are more heat resistant than other strains, in contrast with some reports from The Netherlands.

scholarly journals Low-Dose Cold Atmospheric Plasma Promoting Schwann Cells Proliferation By Activating PI3K/Akt/mTOR Pathway

2021 ◽  
Author(s):  
Bibo Ge ◽  
Jie Bao ◽  
Jinwu Chen ◽  
Xinzhong Xu ◽  
Juehua Jing ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Schwann Cells ◽  
Low Dose ◽  
Treatment Time ◽  
Mtor Pathway ◽  
Atmospheric Plasma ◽  
Control Group ◽  
Dbd Plasma ◽  
Cold Atmospheric Plasma ◽  
Plasma Device

Abstract Cold atmospheric plasma (CAP) is an emerging technology that has attracted the attention of many researchers in many fields and disciplines. In this study, a dielectric barrier discharge (DBD) plasma device was used to treat Schwann cells (SCs) cultured in vitro, and the effect of CAP on SCs proliferation was evaluated by cell morphology, cell viability, cell cycle and expression of related proteins in SCs. The results showed that the production of intracellular ROS and RNS increased with the increase of CAP treatment time. Compared with the control group, the proliferation of SCs treated with CAP for less than 14 s significantly increased, and and then gradually decreased. Besides, the cell cycle results also showed that more cells were in the S+G2/M phase at this time.The PI3K/Akt/mTOR pathway was activated by low-dose CAP, and the expression of cyclinD1 was consistent with the trend of cell proliferation. In addition, n-acetyl-L-cysteine (NAC) preconditioning significantly prevented CAP-induced cellular changes. In conclusion, low-dose CAP-induced of SCs proliferation was closely related to the PI3K/Akt/mTOR signaling pathway. This study provides a new idea for the treatment of peripheral nerve injury.

Microbial Inactivation and Physicochemical Properties of Ultrasound Processed Pomegranate Juice

2015 ◽  
Vol 78 (3) ◽  
pp. 531-539 ◽  
Author(s):  
ÇİĞDEM UYSAL PALA ◽  
NÜKHET NİLÜFER DEMIREL ZORBA ◽  
GÜLÇİN ÖZCAN
Keyword(s):  
Total Phenolics ◽  
Treatment Time ◽  
Color Difference ◽  
Physicochemical Characteristics ◽  
Microbial Inactivation ◽  
Ultrasound Treatment ◽  
Soluble Solids ◽  
Pomegranate Juice ◽  
E Coli ◽  
Log Linear

The effects of ultrasound treatment at various amplitudes (50, 75, and 100%) and times (0, 6, 12, 18, 24, and 30 min) on Escherichia coli ATCC 25922 (a surrogate for E. coli O157:H7) and Saccharomyces cerevisiae ATCC 2366 levels and physicochemical characteristics (monomeric anthocyanins, color values, total phenolics, pH, and soluble solids) were determined in pomegranate juice. More than a 5-log inactivation of E. coli ATCC 25922 and a 1.36-log inactivation of S. cerevisiae ATCC 2366 were achieved after 30 min of ultrasound treatment at 100%amplitude. The log-linear and Weibull models were successfully used to estimate the microbial inactivation as a function of ultrasound treatment time (R2 &gt; 0.97). No significant changes were observed in total phenolics, pH, and soluble solids of the treated juice (P &gt; 0.05). The ultrasound treatment for up to 30 min resulted in more than 92 and 89% anthocyanin retention at 75 and 100% amplitude, respectively. The redness (a*) of the juice did not change significantly after the ultrasound treatment at amplitudes of 75 and 100% for up to 24 and 12 min, respectively. No significant changes in L* and b* values were observed after ultrasound treatment at all amplitudes and after up to 30 min of treatment for 50 and 75% amplitudes. Small differences in juice color were noted based on total color difference scores.

scholarly journals Contact-Free Inactivation of Candida albicans Biofilms by Cold Atmospheric Air Plasma

2012 ◽  
Vol 78 (12) ◽  
pp. 4242-4247 ◽  
Author(s):  
Tim Maisch ◽  
Tetsuji Shimizu ◽  
Georg Isbary ◽  
Julia Heinlin ◽  
Sigrid Karrer ◽  
...  
Keyword(s):  
Health Care ◽  
Candida Albicans ◽  
Treatment Time ◽  
Atmospheric Plasma ◽  
Air Plasma ◽  
Content Type ◽  
Cold Atmospheric Plasma ◽  
Promising Tool ◽  
Plasma Device ◽  
Contact Free

ABSTRACTCandida albicansis one of the main species able to form a biofilm on almost any surface, causing both skin and superficial mucosal infections. The worldwide increase in antifungal resistance has led to a decrease in the efficacy of standard therapies, prolonging treatment time and increasing health care costs. Therefore, the aim of this work was to demonstrate the applicability of atmospheric plasma at room temperature for inactivatingC. albicansgrowing in biofilms without thermally damaging heat-sensitive materials. This so-called cold atmospheric plasma is produced by applying high voltage to accelerate electrons, which ionize the surrounding air, leading to the production of charged particles, reactive species, and photons. A newly developed plasma device was used, which exhibits a large plasma-generating surface area of 9 by 13 cm (117 cm2). Different time points were selected to achieve an optimum inactivation efficacy range of ≥3 log10to 5 log10reduction in CFU per milliliter, and the results were compared with those of 70% ethanol. The results obtained show that contact-free antifungal inactivation ofCandidabiofilms by cold atmospheric plasma is a promising tool for disinfection of surfaces (and items) in both health care settings and the food industry, where ethanol disinfection should be avoided.

scholarly journals Effects of Valproate Monotherapy on the Oxidant-Antioxidant Status in Mexican Epileptic Children: A Longitudinal Study

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Eduardo Beltrán-Sarmiento ◽  
Cindy K. Arregoitia-Sarabia ◽  
Esaú Floriano-Sánchez ◽  
Roberto Sandoval-Pacheco ◽  
Diana E. Galván-Hernández ◽  
...  
Keyword(s):  
Antioxidant Status ◽  
Seizure Activity ◽  
Treatment Time ◽  
Antioxidant Enzyme Activities ◽  
Healthy Children ◽  
Before And After ◽  
Epileptic Children ◽  
Positive Correlations ◽  
First Time ◽  
Antioxidant Effects

Epilepsy is a neurological disorder that can produce brain injury and neuronal death. Several factors such as oxidative stress have been implicated in epileptogenesis. Valproic acid (VPA) is a widely used drug for the treatment of epilepsy, but the mechanisms underlying these benefits are complex and still not fully understood. The objective of this study was to evaluate, for the first time, the effects of VPA on the oxidant-antioxidant status in Mexican epileptic children before and after 6 or 12 months of treatment with VPA by determining the activities of several plasmatic antioxidant enzymes (glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT)) and oxidant marker (malondialdehyde (MDA), hydrogen peroxide (H2O2), 8-hydroxy-2-deoxyguanosine (8-OHdG), and 3-nitrotyrosine (3-NT) levels) profiles. The possible relationships between these markers and some clinicopathological factors were also evaluated. Plasma samples were obtained from the peripheral blood of 16 healthy children and 32 patients diagnosed with epilepsy, and antioxidant/oxidant markers were measured spectrometrically. Significant decreases in all antioxidant enzyme activities, with the exception of GPx, and increases in all oxidant markers in epileptic subjects versus healthy children were observed. Interestingly, all these effects reverted after VPA monotherapy, although the results were different depending on the treatment period (6 or 12 months). These changes were contingent upon brain imaging findings, type of epilepsy, etiology of epilepsy, and the efficacy of 6 months of VPA monotherapy. Significant and positive correlations of GPx and SOD activities and H2O2 and 8-OHdG levels with the age of children at the beginning of treatment were observed. H2O2 levels were also positively correlated with number of seizures before VPA monotherapy. VPA showed significant antioxidant effects decreasing seizure activity, possibly depending on the presence of cerebral structural alterations, treatment time, and age.

Sign in / Sign up

Export Citation Format

Share Document