scholarly journals Longevity of Apis mellifera workers fed on a diet incorporating entomopathogens

2019 ◽  
Vol 86 ◽  
Author(s):  
Fernanda Caroline Colombo ◽  
Rodrigo Mendes Antunes Maciel ◽  
Gabriela Libardoni ◽  
Fernanda Raulino ◽  
Everton Ricardi Lozano ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Apis Mellifera ◽  
Tween 80 ◽  
Distilled Water ◽  
Flat Bottom ◽  
Morphological Alterations ◽  
Glass Tubes ◽  
Qualitative Analyses ◽  
Scanning Electron

ABSTRACT: The present study had the objective of evaluating the longevity of A. mellifera workers fed on a diet incorporating commercial entomopathogens, Beauveria bassiana, and Bacillus thuringiensis. It also aimed at verifying possible morphological alterations in the midgut. To this purpose, the entomopathogens used were B. bassiana (Product A) (5.0 × 1011 viable conidia.kg-1), B. thuringiensis (Product B) (2.5 × 109 viable spores.g-1), and B. thuringiensis (Product C) (1.0 × 109 viable spores.g-1); and two controls: T1: sterilized distilled water, and T2: sterilized distilled water + Tween 80® (0.01%). For the bioassays, 2 mL of each treatment were incorporated into Candy paste. For each treatment, 80 bees were individually in flat bottom glass tubes (2.5 cm Ø) covered with voile, containing a piece of cotton soaked in water and Candy paste. These tubes were stored in a B.O.D (30 ± 2°C, R.H 70% ± 10%, 12 h), and mortality was evaluated every six hours, for 10 days. Soon after verifying mortality, two bees per treatment were selected for the removal of their midgut. Midgut samples were processed using standard methodology for Scanning Electron Microscopy (SEM). It was verified that products A, B, and C reduced the longevity of bees when compared to T1 and T2 controls. In the qualitative analyses carried out using SEM, it was not possible to observe external or internal morphological alterations to midgut tissues. Although products A, B, and C cause a reduction in longevity, their presence was not verified when tissues were analyzed using SEM.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

scholarly journals SEM, EDS and Electrical Capacitance Study on Electrodeposited Ni-Cu Layers

2019 ◽  
Vol 70 (9) ◽  
pp. 3210-3212
Author(s):  
Oana Claudia Ciobotea Barbu ◽  
Ioana Alina Ciobotaru ◽  
Anca Cojocaru ◽  
Florin Mihai Benga ◽  
Danut Ionel Vaireanu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Electrochemical Method ◽  
Steel Substrate ◽  
Distilled Water ◽  
Electrical Capacitance ◽  
Nickel Copper ◽  
Scanning Electron

Nickel-Copper metallic layers were deposited onto a steel substrate by using the electrochemical method. The morphology and the chemical composition of the deposited layers were studied by scanning electron microscopy. The electrical capacitance was measured on a functional supercapacitor made of two Ni-Cu deposited layers and a Nafion 117� membrane hydrated with distilled water, which served as a dielectric separator.

Ultrastructure of the Tertiary Envelope of the Cyst of the Tadpole Shrimp Triops longicaudatus (Branchiopoda; Notostraca)

2000 ◽  
Vol 6 (S2) ◽  
pp. 872-873
Author(s):  
James R. Rosowski ◽  
Terry L. Bartels ◽  
James F. Colburn ◽  
Jannell L. Colton ◽  
Denton Belk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fairy Shrimp ◽  
Distilled Water ◽  
Thin Sections ◽  
Rainfall Events ◽  
Transmission Electron ◽  
Tadpole Shrimp ◽  
Species Specific ◽  
Scanning Electron

Tadpole shrimp inhabit temporary freshwater pools and ponds where their occurrence is largely regulated by rainfall events and water temperature. When dry basins are flooded, cysts of Triops imbibe water and hatch to produce rapidly growing, carapaced larvae. While previous studies show anostracan (fairy shrimp) cyst-surface morphology often species specific, few studies illustrate shell ultrastructure of Triops and none has considered T. longicaudatus. Here we examine the shell of T. longicaudatus (Notostraca) and compare its fine structure to other species of Triops and to that of Artemiafranciscana(Anostraca), which we previously studied.Cysts, produced in culture from Utah broodstock, were purchased from Triops, Inc., 1924 Creighton Rd., Pensacola, FL 32504. Thin sections of cysts were prepared for transmission electron microscopy (TEM) as previously described (Fig. 1). Cysts were also examined with scanning electron microscopy (SEM), dry, whole or fractured (Figs. 2,3), or after imbibition and/or hatching in oxygen saturated, double-distilled water, at 25 ° C.

scholarly journals Proeryptotic Activity of 4-Hydroxynonenal: A New Potential Physiopathological Role for Lipid Peroxidation Products

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 770
Author(s):  
Mario Allegra ◽  
Ignazio Restivo ◽  
Alberto Fucarino ◽  
Alessandro Pitruzzella ◽  
Sonya Vasto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lipid Peroxidation ◽  
Scanning Electron Microscopy ◽  
Flow Cytometry ◽  
Endothelial Cells ◽  
Caspase 3 ◽  
Morphological Alterations ◽  
Signalling Molecule ◽  
Free Haemoglobin ◽  
Scanning Electron

Background: Eryptosis is a physiological, apoptosis-like death of injured erythrocytes crucial to prevent premature haemolysis and the pathological sequalae generated by cell-free haemoglobin. When dysregulated, the process is associated to several inflammatory-based pathologies. 4-Hydroxy-trans-2-nonenal (HNE) is an endogenous signalling molecule at physiological levels and, at higher concentrations, is involved in the pathogenesis of several inflammatory-based diseases. This work evaluated whether HNE could induce eryptosis in human erythrocytes. Methods: Measurements of phosphatidylserine, cell volume, intracellular oxidants, Ca++, glutathione, ICAM-1, and ceramide were assessed by flow cytometry. Scanning electron microscopy evaluated morphological alterations of erythrocytes. Western blotting assessed caspases. PGE2 was measured by ELISA. Adhesion of erythrocytes on endothelial cells was evaluated by gravity adherence assay. Results: HNE in the concentration range between 10–100 µM induces eryptosis, morphological alterations correlated to caspase-3 activation, and increased Ca++ levels. The process is not mediated by redox-dependent mechanisms; rather, it strongly depends on PGE2 and ceramide. Interestingly, HNE induces significant increase of erythrocytes adhesion to endothelial cells (ECs) that are in turn dysfunctionated as evident by overexpression of ICAM-1. Conclusions: Our results unveil a new physiopathological role for HNE, provide mechanistic details of the HNE-induced eryptosis, and suggest a novel mechanism through which HNE could exert pro-inflammatory effects.

The Effect of Different Silica Compositions to the Properties of Silica Foam Fabricated Using Slurry Method

2017 ◽  
Vol 888 ◽  
pp. 121-125 ◽  
Author(s):  
Syazwani Baharom ◽  
Sufizar Ahmad ◽  
Muhamad Izranuddin Mohd Ramli
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Polyethylene Glycol ◽  
Morphological Analysis ◽  
Strength Test ◽  
Distilled Water ◽  
Compressive Strength Test ◽  
Slurry Method ◽  
Scanning Electron

Silica foams with 50% – 70% porosity have been developed by mixing silica powder, polyethylene glycol (PEG) and carboxymethyl cellulose (CMC) into distilled water to make slurry. Polyurethane foam (PU) as the template is immersed into the slurry with 45 wt.%, 50 wt.% and 55 wt.%. of silica composition and finally sintered at 1100°C, 1200°C, 1300°C and 1400°C. Several tests which are morphological analysis, porosity and density test, and compressive strength test are compulsory to determine the physical and mechanical of the silica foam. The morphology of the foam has been observed using Scanning Electron Microscopy (SEM) and the result of pore size distribution is in the range of 255.91 μm to 489.14 μm. The porosity and density obtained from the porosity and density test was 50%-73.66% and 0.5499 g/cm³ up to 0.9757 g/cm³, respectively. Meanwhile, the compressive strength of sintered silica foam obtained is 0.01471 N/mm² up to 0.1467 N/mm².

scholarly journals Effect of metal ions and surfactants on the enzymatic hydrolysis of pretreated lignocellulose

BioResources ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1653-1667
Author(s):  
Yawen Zhou ◽  
Jian Yang ◽  
Cong Luo ◽  
Bo Yang ◽  
Changyao Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Enzymatic Hydrolysis ◽  
Infrared Spectrum ◽  
Metal Ions ◽  
Spectrum Analysis ◽  
Tween 80 ◽  
High Porosity ◽  
Hydrolysis Of ◽  
Scanning Electron

The effect of metal ions and surfactants on the enzymatic hydrolysis of pretreated wheat straw lignocellulose was investigated. Scanning electron microscopy, infrared spectrum analysis, dynamic light scattering, and fluorescence spectra analysis were used to characterize the influence of Fe3+/ polyoxyethylene (20) sorbitan monooleate (Tween 80). The interaction between Fe3+/Tween 80 and enzyme was further investigated by enzyme kinetics and enzyme activity measurements. The best synergistic effect was obtained when the ratio of Fe3+ and Tween 80 was 0.06. The scanning electron microscopy images showed that the Fe3+/Tween 80 combination was associated with high porosity substrates. The infrared spectrum analysis indicated that the components of the substrates depended on additive types. The highest relative enzymatic activity increase rate was obtained with added Fe3+/ Tween 80. The Vmax and Km values of the group with added Fe3+/Tween 80 were much higher than that of the group without additives. With the addition of Fe3+/ Tween 80, the intensity of the fluorescence emission peak decreased and the peak shifted towards a longer wavelength.

Preparation and Characterization of Cordierite Powder via Tween-80 Modified Citrate Sol-Gel Method

2010 ◽  
Vol 148-149 ◽  
pp. 929-933
Author(s):  
Yu Yue Wang ◽  
Juan Juan Feng ◽  
Yi Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Citric Acid ◽  
Metal Ion ◽  
Sol Gel ◽  
Chelating Agent ◽  
Particle Morphology ◽  
Tween 80 ◽  
Solvent Evaporation Process ◽  
Scanning Electron

In this paper, cordierite (2MgO•2Al2O3•5SiO2) precursors are synthesized using TEOS and aluminum and magnesium nitrates as starting materials, citric acid as chelating agent and Tween-80 as dispersant. The effect of citric acid and Tween-80 on the formation mechanism of α-cordierite phase is investigated by using X-ray diffraction (XRD), while the effect of citric acid and Tween-80 on the particle morphology of α-cordierite is examined by using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM). The results show that citric acid used as chelating agent can reduce the formation temperature of α-cordierite to 1150°C by forming stable salt of citric acid with all the metal ion to avoid composition deviation from the sample components during solvent evaporation process and sub-micron cordierite particles without hard agglomeration can be obtained. Nano-sized α-cordierite can be obtained with the introduction of Tween-80 as dispersant by modifying the surfaces of the colloidal sol particles.

scholarly journals Damage of the Bacterial Cell Envelope by Antimicrobial Peptides Gramicidin S and PGLa as Revealed by Transmission and Scanning Electron Microscopy

2010 ◽  
Vol 54 (8) ◽  
pp. 3132-3142 ◽  
Author(s):  
Mareike Hartmann ◽  
Marina Berditsch ◽  
Jacques Hawecker ◽  
Mohammad Fotouhi Ardakani ◽  
Dagmar Gerthsen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Peptides ◽  
Lipid Membrane ◽  
Ultrastructural Changes ◽  
Morphological Alterations ◽  
Bacterial Membranes ◽  
E Coli ◽  
Gramicidin S ◽  
Scanning Electron

ABSTRACT Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the ultrastructural changes in bacteria induced by antimicrobial peptides (AMPs). Both the β-stranded gramicidin S and the α-helical peptidyl-glycylleucine-carboxyamide (PGLa) are cationic amphiphilic AMPs known to interact with bacterial membranes. One representative Gram-negative strain, Escherichia coli ATCC 25922, and one representative Gram-positive strain, Staphylococcus aureus ATCC 25923, were exposed to the AMPs at sub-MICs and supra-MICs in salt-free medium. SEM revealed a shortening and swelling of the E. coli cells, and multiple blisters and bubbles formed on their surface. The S. aureus cells seemed to burst upon AMP exposure, showing open holes and deep craters in their envelope. TEM revealed the formation of intracellular membranous structures in both strains, which is attributed to a lateral expansion of the lipid membrane upon peptide insertion. Also, some morphological alterations in the DNA region were detected for S. aureus. After E. coli was incubated with AMPs in medium with low ionic strength, the cells appeared highly turgid compared to untreated controls. This observation suggests that the AMPs enhance osmosis through the inner membrane, before they eventually cause excessive leakage of the cellular contents. The adverse effect on the osmoregulatory capacity of the bacteria is attributed to the membrane-permeabilizing action of the amphiphilic peptides, even at low (sub-MIC) AMP concentrations. Altogether, the results demonstrate that both TEM and SEM, as well as appropriate sample preparation protocols, are needed to obtain detailed mechanistic insights into peptide function.

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