scholarly journals Mixture of Sodium Hypochlorite and Hydrogen Peroxide on Adhered Aeromonas hydrophila to Solid Substrate in Water: Impact of Concentration and Assessment of the Synergistic Effect

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Chrétien Lontsi Djimeli ◽  
Antoine Tamsa Arfao ◽  
Olive V. Noah Ewoti ◽  
Mireille Ebiane Nougang ◽  
Marlyse L. Moungang ◽  
...  

The synergistic effects of the combined treatments of NaOCl and H2O2 on the elimination of A. hydrophila adhered to polythene under static and dynamic conditions were evaluated. The concentrations 0.1, 0.2, and 0.3‰ NaOCl and 0.5, 1, and 1.5‰ H2O2 were used. The contact periods were 180, 360, 540, and 720 minutes. The abundance of cells adhered reached 2.47 and 2.27 units (log (CFU/cm²)), respectively, under static and dynamic conditions after action of the mixture of disinfectants, whereas it reached 2.41 and 3.39 units (log (CFU/cm²)) after action of NaOCl and H2O2 alone, respectively. Increase in the incubation period resulted in a significant decrease in the abundance of cells adhered when the mixture of 0.3‰ NaOCl and 1.5‰ H2O2 was used (P<0.01). For each cell growth phase, there was a significant difference amongst the mean densities of cells adhered after action of the mixture of disinfectants (P<0.05). Although the Freundlich isotherm parameters relatively varied from one experimental condition to another, the Kf value registered in the exponential growth phase was relatively higher in static state than in dynamic regime; cells adhered under dynamic condition seem more sensitive to the synergistic action than those adhered under static condition.

2021 ◽  
Author(s):  
Müge Cavdan ◽  
Knut Drewing ◽  
Katja Doerschner

AbstractThe softness of objects can be perceived through several senses. For instance, to judge the softness of our cat’s fur, we do not only look at it, we also run our fingers in idiosyncratic ways through its coat. Recently, we have shown that haptically perceived softness covaries with the compliance, viscosity, granularity, and furriness of materials (Dovencioglu et al.,2020). However, it is unknown whether vision can provide similar information about the various aspects of perceived softness. Here, we investigated this question in an experiment with three conditions: in the haptic condition, blindfolded participants explored materials with their hands, in the visual-static condition participants were presented with close-up photographs of the same materials, and in the visual-dynamic condition participants watched videos of the hand-material interactions that were recorded in the haptic condition. After haptically or visually exploring the materials participants rated them on various attributes. Our results show a high overall perceptual correspondence between the three experimental conditions. With a few exceptions, this correspondence tended to be strongest between haptic and visual-dynamic conditions. These results are discussed with respect to information potentially available through the senses, or through prior experience, when judging the softness of materials.


2013 ◽  
Vol 31 (1) ◽  
pp. 99-103 ◽  
Author(s):  
MÁRTA JANÁKY ◽  
JUDIT BORBÉLY ◽  
GYÖRGY BENEDEK ◽  
BALÁZS PÉTER KOCSIS ◽  
GÁBOR BRAUNITZER

AbstractIt is a matter of debate whether X-linked dichromacy is accompanied by enhanced achromatic processing. In the present study, we used sinusoidally modulated achromatic gratings under photopic conditions to compare the contrast sensitivity (CS) of protanopes, deuteranopes, and normal trichromats. 36 male volunteers were examined. CS was tested in static and dynamic conditions at nine different spatial frequencies. The results support the assumption that X-linked color-defective observers are at an advantage in terms of achromatic processing. Both protanopes and deuteranopes had significantly better CS than controls in both the static and the dynamic conditions. In the static condition, the advantage was observed especially at higher spatial frequencies, whereas in the dynamic condition, it was seen also at lower frequencies. The results are interpreted in terms of decreased chromatic modulation of the luminance channel and the early plasticity of the parvocellular system.


2018 ◽  
Vol 69 (1) ◽  
pp. 38-44
Author(s):  
Nicoleta Mirela Marin ◽  
Olga Tiron ◽  
Luoana Florentina Pascu ◽  
Mihaela Costache ◽  
Mihai Nita Lazar ◽  
...  

This study investigates the synergistic effects of ion exchange and biodegradation methods to remove the Acid Blue 193 also called Gryfalan Navy Blue RL (GNB) dye from wastewater. Ion exchange studies were performed using a strongly basic anion exchange resin Amberlite IRA 400. The equilibrium was characterized by a kinetic and thermodynamic points of view, establishing that the sorption of the GNB dye was subject to the Freundlich isotherm model with R2 = 0.8710. Experimental results showed that the activated resin can removed up to 93.4% when the concentration of dye solution is 5.62�10-2 mM. The biodegradation of the GNB was induced by laccase, an enzyme isolated from white-rot fungus. It was also analyzed the role of pH and dye concentration on GNB biodegradation, so 5�10-2 mM dye had a maximum discoloration efficiency of 82.9% at pH of 4. The laccase showed a very fast and robust activity reaching in a few minutes a Km value of 2.2�10-1mM. In addition, increasing the GNB concentration up to 8�10-1 mM did not triggered a substrat inhibition effect on the laccase activity. Overall, in this study we proposed a mixt physicochemical and biological approach to enhance the GNB removal and biodegradability from the wastewaters and subsequently the environment.


2021 ◽  
Vol 11 (4) ◽  
pp. 1510
Author(s):  
Charles Morizio ◽  
Maxime Billot ◽  
Jean-Christophe Daviet ◽  
Stéphane Baudry ◽  
Christophe Barbanchon ◽  
...  

People who survive a stroke are often left with long-term neurologic deficits that induce, among other impairments, balance disorders. While virtual reality (VR) is growing in popularity for postural control rehabilitation in post-stroke patients, studies on the effect of challenging virtual environments, simulating common daily situations on postural control in post-stroke patients, are scarce. This study is a first step to document the postural response of stroke patients to different challenging virtual environments. Five subacute stroke patients and fifteen age-matched healthy adults were included. All participants underwent posturographic tests in control conditions (open and closed eyes) and virtual environment without (one static condition) and with avatars (four dynamic conditions) using a head-mounted device for VR. In dynamic environments, we modulated the density of the virtual crowd (dense and light crowd) and the avoidance space with the avatars (near or far). Center of pressure velocity was collected by trial throughout randomized 30-s periods. Results showed that more challenging conditions (dynamic condition) induced greater postural disturbances in stroke patients than in healthy counterparts. Our study suggests that virtual reality environments should be adjusted in light of obtaining more or less challenging conditions.


Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 162
Author(s):  
Yohei Shimasaki ◽  
Koki Mukai ◽  
Yuki Takai ◽  
Xuchun Qiu ◽  
Yuji Oshima

Peroxiredoxin (Prx) is a relatively recently discovered antioxidant enzyme family that scavenges peroxides and is known to be present in organisms from biological taxa ranging from bacteria to multicellular eukaryotes, including photosynthetic organisms. Although there have been many studies of the Prx family in higher plants, green algae, and cyanobacteria, few studies have concerned raphidophytes and dinoflagellates, which are among the eukaryotic algae that cause harmful algal blooms (HABs). In our proteomic study using 2-D electrophoresis, we found a highly expressed 2-Cys peroxiredoxin (2-CysPrx) in the raphidophyte Chattonella marina var. antiqua, a species that induces mass mortality of aquacultured fish. The abundance of the C. marina 2-CysPrx enzyme was highest in the exponential growth phase, during which photosynthetic activity was high, and it then decreased by about a factor of two during the late stationary growth phase. This pattern suggested that 2-CysPrx is a key enzyme involved in the maintenance of high photosynthesis activity. In addition, the fact that the depression of photosynthesis by excessively high irradiance was more severe in the 2-CysPrx low-expression strain (wild type) than in the normal-expression strain (wild type) of C. marina suggested that 2-CysPrx played a critical role in protecting the cell from oxidative stress caused by exposure to excessively high irradiance. In the field of HAB research, estimates of growth potential have been desired to predict the population dynamics of HABs for mitigating damage to fisheries. Therefore, omics approaches have recently begun to be applied to elucidate the physiology of the growth of HAB species. In this review, we describe the progress we have made using a molecular physiological approach to identify the roles of 2-CysPrx and other antioxidant enzymes in mitigating environmental stress associated with strong light and high temperatures and resultant oxidative stress. We also describe results of a survey of expressed Prx genes and their growth-phase-dependent behavior in C. marina using RNA-seq analysis. Finally, we speculate about the function of these genes and the ecological significance of 2-CysPrx, such as its involvement in circadian rhythms and the toxicity of C. marina to fish.


2005 ◽  
Vol 71 (10) ◽  
pp. 6008-6013 ◽  
Author(s):  
Domitille Fayol-Messaoudi ◽  
Cédric N. Berger ◽  
Marie-Hélène Coconnier-Polter ◽  
Vanessa Liévin-Le Moal ◽  
Alain L. Servin

ABSTRACT The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.


1998 ◽  
Vol 61 (10) ◽  
pp. 1281-1285 ◽  
Author(s):  
VIRGINIE DIEULEVEUX ◽  
MICHELINE GUÉGUEN

d-3-Phenyllactic acid is a compound with anti-Listeria activity which is produced and secreted by the yeastlike fungus, Geotrichum candidum. This compound has a bactericidal effect independent of the physiological State of Listeria monocytogenes when added at a concentration of 7 mg/ml to tryptic soy broth supplemented with yeast extract (TSB-YE). An initial L. monocytogenes population of 105 CFU/ml was reduced 100-fold (2 log) after 4 days of culture at 25 °C in TSB-YE containing d-3-phenyllactic acid. The Listeria population was reduced 1,000-fold (3 log) when the compound was added during the exponential growth phase, and was reduced to less than 10 CFU/ml when it was added during the stationary phase. d-3-Phenyllactic acid had a bacteriostatic effect in UHT whole milk, reducing the population by 4.5 log, to give fewer cells than in the control after 5 days of culture. The results obtained with L. monocytogenes at concentrations of 105 and 103 CFU/ml in cheese curds were less conclusive. d-3-Phenyllactic acid was 10 times less active than nisin in our experimental conditions (TSB-YE at 25°C).


2005 ◽  
Vol 41 (1) ◽  
pp. 40-43
Author(s):  
A. M. Veselovskii ◽  
A. Z. Metlitskaya ◽  
V. A. Lipasova ◽  
I. A. Bass ◽  
I. A. Khmel

2018 ◽  
Vol 5 (10) ◽  
pp. 2726-2732
Author(s):  
Masoum Khoshfetrat ◽  
Sima Davarpanah ◽  
Aliakbar Keykha

Background: Co-administration of drugs with synergistic effects is considered as one of the methods to increase the effectiveness of intrathecal anesthesia and to reduce the need for injectable analgesics. The purpose of this study was to investigate the efficacy of intrathecal midazolam on enhancing the analgesic effect of fentanyl in patients undergoing lower limb surgery. Materials: The present double-blinded clinical trial was conducted on 90 candidate patients undergoing lower limb orthopedic surgery in 2017 at Khatam-Al-Anbiya Hospital in the city of Zahedan, Iran. To this end, the patients were selected via convenience sampling method and then randomly divided into three groups. Afterwards, 3 cc of 0.5% hyperbaric Marcaine was injected intrathecally in the first group, 3 cc of Marcaine + 25 ug of fentanyl was administered to the second group, and 3 cc of Marcaine + 25 ug of fentanyl + 1 mg of midazolam was administered to the third group (the final volume of all three syringes was brought up to 3.7 cc with normal saline). The duration of sensory nerve block and those of motor block and analgesia, as well as changes in vital signs, were then measured in these groups. Moreover, the data were analyzed using SPSS Statistics (Version 22.0) through Chi-square test and one-way analysis of variance (ANOVA). Results: The mean age and gender distribution of the patients in the three study groups did not differ significantly. The mean duration of sensory nerve block was equal to 98.6+/-11.1 min in the first group, 142.2+/-12.4 min in the second group, and 174.3+/-10.9 min in the third group; all showed a statistically significant difference (P=0.0001, P=0.001, P=0.000).The mean duration of analgesia was also reported to be 204.43+/-0.3 min in the first group, 323.62+/-7.4 min in the second group, and 526.22+/-0.9 min in the third group, indicating a statistically significant difference between the three study groups (P=0.0001, P=0.000, P=000). Conclusion: The results of this study demonstrated that adding midazolam to intrathecal fentanyl could significantly increase the duration of sensory nerve block and that of post-operative analgesia.  


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