A Test Device for Microalgal Antifouling Using Fluctuating pH Values on Conductive Paints

Due to the current dependence on biocidal antifouling coatings for biofouling control, there is a continuing international challenge to develop more environmentally acceptable antifouling systems. Fluctuating the pH values on paint surfaces is one of these approaches. We developed an antifouling test device to investigate algal biofilms on conductive paints by using a flume with electrochemically working test panels and subsequent confocal laser scanning microscopy (CLSM) of biofilms. By employing a pole reversal of direct current, fluctuating pH values on the paint surface were generated. As a consequence of the resulting pH stress, colonization of the paint surface by diatoms decreased substantially. The density of biofilm algae decreased with increasing pH fluctuations. However, breaks between electrochemical treatments should not exceed one hour. Overall, we established an experimental setup for testing the antifouling capabilities of electrodes based on conductive paints, which could be used for further development of these varnishes.

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Double-Network Hydrogels of Corn Fiber Gum and Soy Protein Isolate: Effect of Biopolymer Constituents and pH Values on Textural Properties and Microstructures

Foods ◽

10.3390/foods10020356 ◽

2021 ◽

Vol 10 (2) ◽

pp. 356

Author(s):

Jinxin Yan ◽

Xin Jia ◽

Wenjia Yan ◽

Lijun Yin

Keyword(s):

Soy Protein ◽

Laser Scanning ◽

Soy Protein Isolate ◽

Textural Properties ◽

Protein Isolate ◽

Laser Scanning Microscopy ◽

Corn Fiber ◽

Confocal Laser ◽

Double Network ◽

Ph Values

Corn fiber gum (CFG) -soy protein isolate (SPI) double-network (DN) hydrogels were fabricated using laccase and a heat treatment process, in which CFG solution formed the first gel network via laccase oxidation, while SPI formed the second network through heating, as described in our previous research. The aim of this study was to investigate the influences of CFG/SPI constituents (CFG concentration 0–3%, w/v; SPI concentration 8–10%, w/v) and pH values (5.0–7.5) on the textural properties, microstructures and water-holding capacities (WHC) of the CFG-SPI DN hydrogels. Confocal Laser Scanning Microscopy (CLSM) results showed an apparent phase separation when the CFG concentration was above 1% (w/v). The textural characteristics and WHC of most DN hydrogels were enhanced with increasing concentrations of CFG and SPI. Scanning Electron Microscopy (SEM) observations revealed that the microstructures of DN hydrogels were converted from coarse and irregular to smooth and ordered as pH values increased from 5.0 to 7.5. Excellent textural properties and WHC were observed at pH 7.0. This study developed various CFG-SPI DN hydrogels with diverse textures and structures, governed by the concentrations of protein/polysaccharide and pH values, and also contributes to the understanding of gum–protein interactions in DN hydrogels obtained under different conditions.

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Optimizing CNT Loading in Antimicrobial Composites for Urinary Tract Application

Applied Sciences ◽

10.3390/app11094038 ◽

2021 ◽

Vol 11 (9) ◽

pp. 4038

Author(s):

Marisa Gomes ◽

Luciana C. Gomes ◽

Rita Teixeira-Santos ◽

Manuel F. R. Pereira ◽

Olívia S. G. P. Soares ◽

...

Keyword(s):

Urinary Tract ◽

Laser Scanning ◽

Antimicrobial Properties ◽

Surface Hydrophobicity ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Coating Materials ◽

Biofilm Thickness ◽

Angle Measurements ◽

Antifouling Coatings

Several methodologies have been implemented with the intent of preventing or reducing the formation of biofilms on indwelling urinary devices. The use of carbon nanotubes (CNTs) in the biomedical field has been increasing, particularly in the production of antimicrobial and antifouling coatings. Despite their proven antimicrobial properties, their use as coating materials for urinary tract devices (UTDs) is still poorly documented. In the present work, CNT/poly(dimethylsiloxane) (PDMS) composite materials containing different CNT loadings were prepared and further tested against Escherichia coli under conditions prevailing in UTDs. Besides CNT loading optimization, textural modifications were also introduced on the surface of CNTs to improve the antibiofilm pro-perties of the final composites. Material characterization included the textural evaluation of CNTs and the assessment of surface morphology by scanning electron microscopy, while the surface hydrophobicity was determined by contact angle measurements. Biofilm analysis was performed by determining the number of culturable and total cells and by confocal laser scanning microscopy. Results revealed that, by filling the PDMS matrix with 3 wt% CNT loading, a significant reduction in cell culturability (39%) can be achieved compared to PDMS. Additionally, the textural modifications induced by ball-milling treatment proved to be effective on the inhibition of biofilm formation, reducing the amount of biofilm per surface area, biofilm thickness and surface coverage in 31, 47 and 27%, respectively (compared to surfaces where CNTs were not ball-milled).

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Experimental Assessment of the Performance of Two Marine Coatings to Curb Biofilm Formation of Microfoulers

Coatings ◽

10.3390/coatings10090893 ◽

2020 ◽

Vol 10 (9) ◽

pp. 893 ◽

Cited By ~ 1

Author(s):

Sara I. Faria ◽

Rita Teixeira-Santos ◽

Luciana C. Gomes ◽

Elisabete R. Silva ◽

João Morais ◽

...

Keyword(s):

Biofilm Formation ◽

Laser Scanning ◽

Critical Role ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Marine Biofouling ◽

Marine Coatings ◽

Antifouling Coatings ◽

Wet Weight ◽

Biofilm Structure

Biofilms formed on submerged marine surfaces play a critical role in the fouling process, causing increased fuel consumption, corrosion, and high maintenance costs. Thus, marine biofouling is a major issue and motivates the development of antifouling coatings. In this study, the performance of two commercial marine coatings, a foul-release silicone-based paint (SilRef) and an epoxy resin (EpoRef), was evaluated regarding their abilities to prevent biofilm formation by Cyanobium sp. and Pseudoalteromonas tunicata (common microfoulers). Biofilms were developed under defined hydrodynamic conditions to simulate marine settings, and the number of biofilm cells, wet weight, and thickness were monitored for 7 weeks. The biofilm structure was analyzed by confocal laser scanning microscopy (CLSM) at the end-point. Results demonstrated that EpoRef surfaces were effective in inhibiting biofilm formation at initial stages (until day 28), while SilRef surfaces showed high efficacy in decreasing biofilm formation during maturation (from day 35 onwards). Wet weight and thickness analysis, as well as CLSM data, indicate that SilRef surfaces were less prone to biofilm formation than EpoRef surfaces. Furthermore, the efficacy of SilRef surfaces may be dependent on the fouling microorganism, while the performance of EpoRef was strongly influenced by a combined effect of surface and microorganism.

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Starch Combined with Sucrose Provokes Greater Root Dentine Demineralization than Sucrose Alone

Caries Research ◽

10.1159/000486427 ◽

2018 ◽

Vol 52 (4) ◽

pp. 323-330

Author(s):

Samilly Evangelista Souza ◽

Aline Araújo Sampaio ◽

Altair Antoninha Del Bel Cury ◽

Yuri Wanderley Cavalcanti ◽

Antônio Pedro Ricomini Filho ◽

...

Keyword(s):

Laser Scanning ◽

Culture Medium ◽

Surface Hardness ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Salivary Amylase ◽

Cariogenic Bacteria ◽

Ph Values ◽

Biofilm Model ◽

Whole Saliva

Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone.

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3-D imaging of cells using a confocal laser scanning microscope and digital image processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102560 ◽

1988 ◽

Vol 46 ◽

pp. 96-97

Author(s):

Thomas M. Jovin ◽

Michel Robert-Nicoud ◽

Donna J. Arndt-Jovin ◽

Thorsten Schormann

Keyword(s):

Laser Scanning ◽

Confocal Laser Scanning Microscope ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Confocal Laser ◽

Scanning Microscope ◽

Laser Scanning Microscope ◽

Biochemical Processes ◽

Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

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Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158388 ◽

1990 ◽

Vol 48 (3) ◽

pp. 168-169

Author(s):

M. H. Chestnut ◽

C. E. Catrenich

Keyword(s):

Acridine Orange ◽

Mammalian Cells ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Ulcer Disease ◽

Gastroduodenal Disease ◽

H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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A new protocol for live imaging of mammalian retina ex vivo by confocal laser scanning microscopy

Protocol Exchange ◽

10.1038/nprot.2009.101 ◽

2009 ◽

Cited By ~ 1

Author(s):

Isabella Panfoli ◽

Daniela Calzia ◽

Silvia Ravera ◽

Giovanni Candiano ◽

Angela Bachi ◽

...

Keyword(s):

Confocal Laser Scanning Microscopy ◽

Laser Scanning ◽

Ex Vivo ◽

Live Imaging ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Scanning Microscopy ◽

Confocal Laser ◽

Mammalian Retina

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Intravenous Application of Fluorescein for Confocal Laser Scanning Microscopy: Evaluation of Contrast Dynamics and Image Quality with Increasing Injection-to-Imaging Time

Endoskopie heute ◽

10.1055/s-2008-1061279 ◽

2008 ◽

Vol 21 (01) ◽

Author(s):

V Becker ◽

S von Delius ◽

M Bajbouj ◽

A Karagianni ◽

RM Schmid ◽

...

Keyword(s):

Image Quality ◽

Confocal Laser Scanning Microscopy ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Scanning Microscopy ◽

Confocal Laser ◽

Imaging Time ◽

Intravenous Application

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Use of confocal laser scanning microscopy and a computer model to understand ink cavitation and filamentation

TAPPI Journal ◽

10.32964/tj9.10.7 ◽

2010 ◽

Vol 9 (10) ◽

pp. 7-15

Author(s):

HANNA KOIVULA ◽

DOUGLAS BOUSFIELD ◽

MARTTI TOIVAKKA

Keyword(s):

Laser Scanning ◽

Confocal Laser Scanning Microscope ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Confocal Laser ◽

Print Quality ◽

Length Scale ◽

Offset Printing ◽

Significant Difference ◽

Printing Speed

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.

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