scholarly journals Efficacy of Surfactant Combined with Peracetic Acid in Removing Listeria innocua from Fresh Apples

2019 ◽  
Vol 82 (11) ◽  
pp. 1965-1972 ◽  
Author(s):  
EWA PIETRYSIAK ◽  
JULIANNE M. KUMMER ◽  
INES HANRAHAN ◽  
GIRISH M. GANJYAL
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Foodborne Pathogens ◽  
Peracetic Acid ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
Tween 20 ◽  
Microscopy Imaging ◽  
Cleaning Methods ◽  
Scanning Electron

ABSTRACT Large amounts of water used in the apple packing process, the presence of organic matter, and difficult-to-clean equipment are vectors for contaminating apples with foodborne pathogens, such as Listeria monocytogenes. There is a need to develop new cleaning methods for fresh apples and evaluate their antimicrobial efficacy. A series of surfactants of different chemical properties (cationic lauric arginate [LAE], anionic sodium dodecyl sulfate [SDS], and nonionic Tween 20 [T20]) alone and combined with peracetic acid (PAA) were evaluated for their efficiency in the removal of L. innocua, a surrogate of L. monocytogenes, from fresh apples. Whole fresh apples were inoculated with L. innocua (7 log CFU/mL) by a dipping method, dried, and subjected to wash treatments with selected cleaning solutions (water, PAA, PAA-LAE, PAA-SDS, and PAA-T20). The contact angle between the cleaning solutions and the surface of the apples was measured. The antimicrobial activity of the cleaning solutions and the efficacy of the cleaning treatment were evaluated by enumeration of L. innocua from treated apples and visualized by scanning electron microscopy. Stem bowl and calyx cavities of the apple harbored higher bacteria concentrations (∼4.82 log CFU per apple), compared with the equatorial section (∼2.66 log CFU per apple). Addition of 0.1% of selected surfactants led to a significant decrease in surface tension of cleaning solutions and allowed better spreading on the apple surface. Surfactants combined with PAA solution resulted in higher L. innocua reduction compared with PAA alone; however, their efficacy was limited. The most effective cleaning solution was PAA-T20, with reduction of approximately 2.2 log. Scanning electron microscopy imaging confirmed that most bacteria were harbored inside the surface irregularities. PAA alone and with surfactants caused damage and deformation of bacteria cells. Cleaning apples with PAA combined with surfactants may improve microbial safety in whole apples; however, the efficiency of the decontamination treatment can be reduced because of variations in apple morphology.

scholarly journals Intraocular lens biofilm formation supported by scanning electron microscopy imaging

2019 ◽  
Vol 67 (10) ◽  
pp. 1708
Author(s):  
Dipankar Das ◽  
Harsha Bhattacharjee ◽  
Krishna Gogoi ◽  
JayantaK Das ◽  
Puneet Misra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Intraocular Lens ◽  
Biofilm Formation ◽  
Microscopy Imaging ◽  
Scanning Electron

scholarly journals Correlation of X-ray Computed Nanotomography and Scanning Electron Microscopy Imaging of Collagen Scaffolds

2018 ◽  
Vol 24 (S2) ◽  
pp. 104-105
Author(s):  
Dominika Kalasova ◽  
Veronika Pavlinakova ◽  
Tomas Zikmund ◽  
Lucy Vojtova ◽  
Jozef Kaiser
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Collagen Scaffolds ◽  
Microscopy Imaging ◽  
X Ray ◽  
X Ray Computed ◽  
Scanning Electron

Failure Analysis of High Pressure Container using Fractography and Material Morphology

2018 ◽  
Vol 773 ◽  
pp. 287-291
Author(s):  
Eui Soo Kim
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Failure Analysis ◽  
Large Scale ◽  
Chemical Properties ◽  
Accurate Analysis ◽  
Internal Pressures ◽  
Scanning Electron ◽  
And Chemical Properties

High-pressure gas containers must be able to withstand high internal pressures because they store compressed gases. Otherwise, cracks or defects may lead to an explosion, which may in turn lead to a large-scale disaster. Therefore, accurate analysis of the causes of cracks or defects and various techniques for detecting cracks or defects are needed. In this research, we analyzed the failure mechanism of a high-pressure gas container through fractography using scanning electron microscopy and optical microscopy and through measurements of their mechanical and chemical properties.

scholarly journals In Vitro Effect of Modified Polyetheretherketone (PEEK) Implant Abutments on Human Gingival Epithelial Keratinocytes Migration and Proliferation

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1401 ◽  
Author(s):  
Liza L. Ramenzoni ◽  
Thomas Attin ◽  
Patrick R. Schmidlin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tetrazolium Salt ◽  
Microscopy Imaging ◽  
Implant Abutments ◽  
And Migration ◽  
Vitro Effect ◽  
Scanning Electron ◽  
Proliferation And Migration

Improving soft tissue attachment to implant abutments is a crucial factor for enduring health and maintenance of soft peri-implant tissue health. In this in vitro study we aimed to compare the biocompatibility of three different abutment surfaces: titanium, zirconia and modified polyetheretherketone (PEEK). Surface topography, roughness and wettability were investigated with scanning electron microscopy, profilometer and contact angle meter, respectively. Human gingival epithelial keratinocytes were examined for viability, morphology, proliferation and migration by using tetrazolium salt colorimetric assay, scanning electron microscopy imaging, immunofluorescence bromodeoxyuridine analysis and scratch wound healing assays. Roughness measurements revealed differences between the investigated surfaces. Keratinocytes cultured on all examined surfaces indicated adhesion and attachment by means of scanning electron microscopy imaging. Cell viability assays showed no significant differences between the groups (p > 0.05). The modified PEEK surface similarly improved surface roughness in comparison to titanium and zirconia, which resulted in greater and equivalent cell proliferation and migration. The study methodology showed here may emphasize the importance of cell interactions with different abutment materials, which in part increases the changes of implant success. PEEK, titanium and zirconia surface types used in this study showed mostly similar epithelial biological responses.

scholarly journals Cajuputs candy impairs Candida albicans and Streptococcus mutans mixed biofilm formation in vitro

F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 1923
Author(s):  
Siska Septiana ◽  
Boy Muchlis Bachtiar ◽  
Nancy Dewi Yuliana ◽  
Christofora Hanny Wijaya
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Candida Albicans ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Microscopy Imaging ◽  
Biofilm Inhibition ◽  
Yeast Form ◽  
Melaleuca Cajuputi ◽  
Scanning Electron

Background: Cajuputs candy (CC), an Indonesian functional food, utilizes the bioactivity of Melaleuca cajuputi essential oil (MCEO) to maintain oral cavity health. Synergistic interaction between Candida albicans and Streptococcus mutans is a crucial step in the pathogenesis of early childhood caries. Our recent study revealed several alternative MCEOs as the main flavors in CC. The capacity of CC to interfere with the fungus-bacterium relationship remains unknown. This study aimed to evaluate CC efficacy to impair biofilm formation by these dual cariogenic microbes. Methods: The inhibition capacity of CC against mixed-biofilm comprising C. albicans and S. mutans was assessed by quantitative (crystal violet assay, tetrazolium salt [MTT] assay, colony forming unit/mL counting, biofilm-related gene expression) and qualitative analysis (light microscopy and scanning electron microscopy). Result: Both biofilm-biomass and viable cells were significantly reduced in the presence of CC. Scanning electron microscopy imaging confirmed this inhibition capacity, demonstrating morphology alteration of C. albicans, along with reduced microcolonies of S. mutans in the biofilm mass. This finding was related to the transcription level of selected biofilm-associated genes, expressed either by C. albicans or S. mutans. Based on qPCR results, CC could interfere with the transition of C. albicans yeast form to the hyphal form, while it suppressed insoluble glucan production by S. mutans. G2 derived from Mojokerto MCEO showed the greatest inhibition activity on the relationship between these cross-kingdom oral microorganisms (p < 0.05). Conclusion: In general, all CC formulas showed biofilm inhibition capacity. Candy derived from Mojokerto MCEO showed the greatest capacity to maintain the yeast form of C. albicans and to inhibit extracellular polysaccharide production by S. mutans. Therefore, the development of dual-species biofilms can be impaired effectively by the CC tested.

scholarly journals Fabrication and Physico-Chemical Properties of Antifungal Samarium Doped Hydroxyapatite Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1466
Author(s):  
Carmen Steluta Ciobanu ◽  
Daniela Predoi ◽  
Patrick Chapon ◽  
Mihai Valentin Predoi ◽  
Simona Liliana Iconaru
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Chemical Properties ◽  
Fourier Transform Infrared ◽  
Orthopedic Implants ◽  
Scanning Electron

Samarium doped hydroxyapatite (Ca10−xSmx(PO4)6(OH)2, xSm = 0.5, 50SmHAp) is a very promising candidate to be used for different coatings in various dental and orthopedic implants. We report, for the first time, the obtaining of 50SmHAp thin films by a cost-effective method, namely spin coating. Thin films of 50SmHAp on silicon substrate have been analyzed by various techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), Metallographic microscopy and Glow Discharge Optical Emission Spectroscopy (GDOES). The stability of 50SmHAp suspension was evaluated by ultrasound measurements. Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were also used to evaluate the 50SmHAp suspension. The antifungal activity of 50SmHAp suspension and coatings was assessed using Candida albicans ATCC 10231 fungal strain (C. albicans). The results of the antifungal assays depicted that both 50SmHAp suspensions and coatings were effective in inhibiting the development of C. albicans fungal cells, thus making them ideal candidates for the development of novel antifungal agents. The obtained results give new perspective for possible applications of 50SmHAp thin films in various medical applications due to their antifungal properties.

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