scholarly journals Potential Use of Carrageenans against the Limestone Proliferation of the Cyanobacterium Parakomarekiella sesnandensis

2021 ◽  
Vol 11 (22) ◽  
pp. 10589
Author(s):  
Fabiana Soares ◽  
João Trovão ◽  
Francisco Gil ◽  
Lídia Catarino ◽  
Igor Tiago ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cultural Heritage ◽  
Visual Inspection ◽  
Antimicrobial Properties ◽  
Alternative Methods ◽  
Red Seaweed ◽  
Laboratory Conditions ◽  
Potential Use ◽  
Scanning Electron

Stone biodeterioration by cyanobacteria is a common issue in the field of cultural heritage. As they are considered the first stone colonizers, the need to control their growth has increased. In this study, we evaluated the effectiveness of kappa/iota carrageenans from the red seaweed Chondracanthus teedei var. lusitanicus against the limestone proliferation of the cyanobacterium Parakomarekiella sesnandensis, under laboratory conditions. For this purpose, 200 μL of kappa/iota carrageenans (0.01 g mL−1) were applied into the surface of the limestone replicas prior to their inoculation with P. sesnandensis. Results were evaluated after 4 months of incubation through visual inspection, stereomicroscopy, scanning electron microscopy and colorimetric analyses. The gathered data demonstrated that these types of carrageenans have the potential to reduce the colonization of P. sesnandensis. With one sole application, the aesthetical alterations caused by the proliferation of P. sesnandensis were drastically reduced. This study highlights the need to explore marine-based products, particularly those derived from seaweeds with antimicrobial properties, as alternative methods for biocleaning cultural heritage assets.

scholarly journals Biofilm Inhibition and Antimicrobial Properties of Silver-Ion-Exchanged Zeolite A against Vibrio spp Marine Pathogens

2021 ◽  
Vol 11 (12) ◽  
pp. 5496
Author(s):  
Zarina Amin ◽  
Nur Ariffah Waly ◽  
Sazmal Effendi Arshad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Properties ◽  
Immune Defense ◽  
Silver Ion ◽  
Bacterial Disease ◽  
Zeolite A ◽  
Biofilm Inhibition ◽  
Volcanic Origin ◽  
Scanning Electron

A challenging problem in the aquaculture industry is bacterial disease outbreaks, which result in the global reduction in fish supply and foodborne outbreaks. Biofilms in marine pathogens protect against antimicrobial treatment and host immune defense. Zeolites are minerals of volcanic origin made from crystalline aluminosilicates, which are useful in agriculture and in environmental management. In this study, silver-ion-exchanged zeolite A of four concentrations; 0.25 M (AgZ1), 0.50 M (AgZ2), 1.00 M (AgZ3) and 1.50 M (AgZ4) were investigated for biofilm inhibition and antimicrobial properties against two predominant marine pathogens, V. campbelli and V. parahemolyticus, by employing the minimum inhibitory concentration (MIC) and crystal violet biofilm quantification assays as well as scanning electron microscopy. In the first instance, all zeolite samples AgZ1–AgZ4 showed antimicrobial activity for both pathogens. For V. campbellii, AgZ4 exhibited the highest MIC at 125.00 µg/mL, while for V. parahaemolyticus, the highest MIC was observed for AgZ3 at 62.50 µg/mL. At sublethal concentration, biofilm inhibition of V. campbelli and V. parahemolyticus by AgZ4 was observed at 60.2 and 77.3% inhibition, respectively. Scanning electron microscopy exhibited profound structural alteration of the biofilm matrix by AgZ4. This is the first known study that highlights the potential application of ion-exchanged zeolite A against marine pathogens and their biofilms.

Evaluation of Three Different Cleaners Recommended for Ultrafiltration Systems by Direct Observations of Commercial-Scale Spiral-Wound Ultrafiltration Membranes1

1988 ◽  
Vol 51 (2) ◽  
pp. 89-104 ◽  
Author(s):  
K. E. SMITH ◽  
R. L. BRADLEY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Visual Inspection ◽  
Membrane Materials ◽  
Direct Observations ◽  
Commercial Scale ◽  
Sweet Whey ◽  
Scanning Electron ◽  
Polysulfone Membranes ◽  
Spiral Wound

Efficacy of cleaners designed for use with ultrafiltration systems was determined by microbiological evaluation and through visual inspection using scanning electron microscopy. The ultrafiltration system containing two commercial-scale, polysulfone membranes was soiled with sweet whey (40°C) then rinsed with water and membranes were removed. One half of each membrane was soaked for 2 h at 38°C in one of the following solutions: control (no soaking), acid cleaner (pH 2.5), enzyme-based cleaner (pH 11.5) and chlorinated alkaline cleaner (pH 11.5). The membranes were repositioned in the ultrafiltration unit, rinsed with water, then removed and unwound for analysis. Sections of membrane, retentate spacer and permeate mesh were aseptically removed for enumeration of microorganisms remaining and for examination by scanning electron microscopy. Membranes cleaned with chlorinated alkaline cleaner averaged 2 × 103 CFU/50 cm2, enzyme-based cleaner 6 × 106/CFU, acid anionic cleaner 1 × 107 CFU and the control 5 × 107CFU. Scanning electron microscopy found soil and microorganisms present on all membrane materials exposed to all three cleaners.

scholarly journals Insecticidal effect of diatomaceous earth and dolomite powder against Corn weevil Sitophiluszeamais Motschulsky, 1855 (Coleoptera: Curculionidae)

2020 ◽  
Vol 44 (6) ◽  
pp. 490-497
Author(s):  
Alyssa Cristina Oliveira FREITAS ◽  
Adriana Aparecida Sinopólis GIGLIOLLI ◽  
Ronaldo Roberto Tait CALEFFE ◽  
Helio CONTE
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Surface ◽  
Diatomaceous Earth ◽  
The Body ◽  
Insecticidal Effect ◽  
Laboratory Conditions ◽  
Inert Dusts ◽  
Stored Grains ◽  
Scanning Electron

Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae) which develops inside the grain, is an aggressive pest of stored grains. Here, we evaluated the efficiency of diatomaceous earth (DE), Diatomita CI/325 CX, and dolomite (DOL), Dolomita Dr. Kanyo, against S. zeamais reared on corn under laboratory conditions and observed external alterations on treated insects using scanning electron microscopy (SEM). Insects treated with both DE and DOL were impregnated with particles on the body surface, and they showed 100% mortality after 10 days of exposure. Damages caused by inert dusts may have contributed to dehydration and desiccation, consequently, leading insects to death. Thus, diatomaceous and dolomite were effective against S. zeamais under laboratory conditions.

scholarly journals Pilot investigation into osteotome hard surface coating and cutting-edge degradation

2020 ◽  
Author(s):  
David White ◽  
Jim Bartley ◽  
Christopher Whittington ◽  
Lorenzo M. G. Garcia ◽  
Kaushik Chand ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Nitride ◽  
Visual Inspection ◽  
Visual Analysis ◽  
Electroless Nickel ◽  
Cutting Edge ◽  
Edge Sharpness ◽  
Blade Edge ◽  
Scanning Electron

Abstract BackgroundOsteotomes are bone cutting tools commonly reused in orthopedic surgical procedures. Despite undergoing rigorous cleaning, visual inspection and sterilization procedures between every use, the condition of the cutting blade edge is commonly not qualitatively assessed. Subjective feedback from surgeons suggests a large variation in osteotome cutting edge sharpness is found during use. This study seeks to investigate the retention of osteotome cutting-edge sharpness by comparing the wear resistance of as-supplied, electroless nickel, and titanium nitride coated osteotomes following a series of bone cutting tests.MethodsChanges in edge sharpness were assessed using visual inspection, depth penetration testing that quantified change in the blade sharpness index and scanning electron microscopy visual analysis. Visual inspection of each osteotome blade edge was then compared to qualitative blade sharpness index measurement.ResultsAfter use, no cutting-edge damage or change in blade sharpness was detected by visual examination of all three osteotomes however the as-supplied osteotome demonstrated 50% loss of blade sharpness index compared to 30% and 15% reduction for the electroless nickel and titanium nitride coated osteotomes respectively. This finding was supported by scanning electron microscopy evaluation that found greater mechanical damage had occurred along the cutting-edge of the as-supplied osteotome compared to the two coated with wear resistant materials.ConclusionsThe rapid loss of blade sharpness found in the as-supplied osteotome supports the degradation in cutting performance frequently reported by surgeons. The findings from this study demonstrates blade sharpness index better detects cutting edge wear compared to visual inspection. Results from this pilot study also suggest the coating of osteotomes in hard-wearing biocompatible materials assists in retaining cutting edge sharpness over multiple uses. Further study using a larger sample size is required to validate these findings.

scholarly journals New registers of colleters in species of Myrtaceae from Brazilian Cerrado

Rodriguésia ◽  
2019 ◽  
Vol 70 ◽  
Author(s):  
Cleber José da Silva ◽  
João Paulo Oliveira Ribeiro ◽  
Renata Maria Strozi Alves Meira
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Fleshy Fruit ◽  
Brazilian Cerrado ◽  
Secretory Structures ◽  
Histochemical Tests ◽  
Potential Use ◽  
Scanning Electron

Abstract Colleters are secretory structures that produce a sticky substance, consisting of a mixture of mucilage, proteins, terpenes, pectic substances and even alkaloids, which lubricates and protects the shoot apical meristem. Several colleter types have been described and have taxonomic value in many botanical families. In Myrtaceae, the colleters description is recent and presents three new morphological types (conic, euryform and petaloid) that differ those already described for other eudicots. In this work, we report the colleters morphological types in six species of three genera belonging to the Myrteae tribe of Myrtoideae from the Brazilian Cerrado. The samples were fixed for light and scanning electron microscopy. Histochemical tests were carried out on the fresh and methacrylate-embedded material. The conic and euryform colleters from Myrtoideae species of the Cerrado did not differ either morphologically nor as to the secretion nature from those described for Myrtoideae species from others biomes, which may indicate their potential use for taxonomic purposes. Considering the hypothesis that the multiple fleshy-fruit lineages have evolved independently in Myrteae tribe, our results indicate the relevance of additional studies in order to recognize the pattern of distribution of colleters in Myrtaceae.

scholarly journals Synthesis of Hydroxyapatite-Ag Composite as Antimicrobial Agent

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582095134
Author(s):  
Pamela Nair Silva-Holguín ◽  
Simón Yobanny Reyes-López
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Drug Resistance ◽  
Silver Nanoparticles ◽  
Antimicrobial Agents ◽  
Sol Gel ◽  
Antimicrobial Properties ◽  
Low Concentrations ◽  
Silver Nanocomposite ◽  
Scanning Electron

Innovative and improved antimicrobial agents by nanotechnology are developed to control and mitigation of resistant microorganisms. Nanoparticles of metals or oxide metals be able to be toxic to bacteria, demonstrating biocidal behaviors at low concentrations. The integration of silver nanoparticles in ceramic matrices has enhanced the antimicrobial performance, resulting in the search for new composites with improved bactericidal properties. The aim of this study was to prepare and characterize hydroxyapatite-silver nanocomposite and evaluate its antimicrobial properties against various Gram-positive and negative bacteria related to drug-resistance infections. Hydroxyapatite nanopowders were produced by sol-gel and silver nanoparticles were synthesized by reduction of Ag+ions with the simple addition of gallic acid. Hydroxyapatite-silver composite (HAp-AgNPs) was prepared by adsorption of AgNPs at several concentrations. The results of UV–visible spectroscopy, dynamic light scattering, and transmission scanning electron microscopy revealed the existence of AgNPs with diameters around 6 nm. Scanning electron microscopy and energy dispersive X-ray spectroscopy corroborated the presence of silver disseminated over the surface of hydroxyapatite nanopowders. All HAp-AgNPs composites demonstrated excellent antibacterial effect even at lower silver concentration. HAp-AgNPs composites have a higher possibility for medical applications focused no the control of microorganisms with drug-resistance.

scholarly journals Biofilm Inhibition and Antimicrobial Properties of Silver Ion-Exchanged Zeolite a against Vibrio spp Marine Pathogens

2021 ◽  
Author(s):  
Zarina Amin ◽  
SAZMAL EFFENDI ARSHAD ◽  
NUR ARIFAH WALY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Properties ◽  
Antimicrobial Treatment ◽  
Silver Ion ◽  
Bacterial Disease ◽  
Zeolite A ◽  
Biofilm Inhibition ◽  
Volcanic Origin ◽  
Scanning Electron

A challenging problem in the aquaculture industry is bacterial disease outbreaks which results in the global reduction of fish supply and foodborne outbreaks. Biofilms in marine pathogens protect against antimicrobial treatment and host immune defence. Zeolites are minerals of volcanic origin made from crystalline aluminosilicates which are useful in agriculture and in environmental management. In this study, silver ion-exchanged zeolite A of four concentrations; 0.25M (AgZ1), 0.50M (AgZ2), 1.00M (AgZ3)and 1.50M (AgZ4) were investigated for biofilm inhibition and antimicrobial properties against two predominant marine pathogens V. campbelli and V. parahemolyticus by employing the Minimum Inhibitory Concentration(MIC), Crystal Violet Biofilm Quantification assays as well as Scanning Electron Microscopy. In the first instance, all zeolite samples AgZ1-AgZ4 showed antimicrobial activity for both pathogens. For V. campbellii AgZ4 exhibited the highest MIC at 125.00 µg/ml while for V. parahaemolyticus the highest MIC was observed for AgZ3 at 62.50 µg/ml. At sublethal concentration, biofilm inhibition of V. campbelli and V. parahemolyticus by AgZ4 were observed at 60.2% and 77.3% inhibition respectively. Scanning electron microscopy exhibited profound structural alteration of the biofilm matrix by AgZ4. This is the first known study that highlights the potential application of ion-exchanged Zeolite A against marine pathogens and their biofilms.

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