scholarly journals Monitoring Candida parapsilosis and Staphylococcus epidermidis Biofilms by a Combination of Scanning Electron Microscopy and Raman Spectroscopy

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4089 ◽  
Author(s):  
Kamila Hrubanova ◽  
Vladislav Krzyzanek ◽  
Jana Nebesarova ◽  
Filip Ruzicka ◽  
Zdenek Pilat ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Sample Preparation ◽  
Staphylococcus Epidermidis ◽  
Candida Parapsilosis ◽  
Freeze Fracture ◽  
Biofilm Structure ◽  
Scanning Electron

The biofilm-forming microbial species Candida parapsilosis and Staphylococcus epidermidis have been recently linked to serious infections associated with implanted medical devices. We studied microbial biofilms by high resolution scanning electron microscopy (SEM), which allowed us to visualize the biofilm structure, including the distribution of cells inside the extracellular matrix and the areas of surface adhesion. We compared classical SEM (chemically fixed samples) with cryogenic SEM, which employs physical sample preparation based on plunging the sample into various liquid cryogens, as well as high-pressure freezing (HPF). For imaging the biofilm interior, we applied the freeze-fracture technique. In this study, we show that the different means of sample preparation have a fundamental influence on the observed biofilm structure. We complemented the SEM observations with Raman spectroscopic analysis, which allowed us to assess the time-dependent chemical composition changes of the biofilm in vivo. We identified the individual spectral peaks of the biomolecules present in the biofilm and we employed principal component analysis (PCA) to follow the temporal development of the chemical composition.

Development of the Foramen Secundum in the Chick as Observed by Scanning Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 212-213
Author(s):  
M.J.C. Hendrix ◽  
D.E. Morse
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Procaine Hydrochloride ◽  
Cardiac Anomaly ◽  
Chick Embryos ◽  
Congenital Cardiac Anomaly ◽  
Septal Defects ◽  
Critical Point Drying ◽  
Scanning Electron

Atrial septal defects are considered the most common congenital cardiac anomaly occurring in humans. In studying the normal sequential development of the atrial septum, chick embryos of the White Leghorn strain were prepared for scanning electron microscopy and the results were then extrapolated to the human heart. One-hundred-eighty chick embryos from 2 to 21 days of age were removed from their shells and immersed in cold cacodylate-buffered aldehyde fixative . Twenty-four embryos through the first week post-hatching were perfused in vivo using cold cacodylate-buffered aldehyde fixative with procaine hydrochloride. The hearts were immediately dissected free and remained in the fixative a minimum of 2 hours. In most cases, the lateral atrial walls were removed during this period. The tissues were then dehydrated using a series of ascending grades of ethanol; final dehydration of the tissues was achieved via the critical point drying method followed by sputter-coating with goldpalladium.

Ultrastructural Features of Normal and Diseased Hair Revealed by Ion Beam Etching and Freeze Fracture

1975 ◽  
Vol 33 ◽  
pp. 358-359
Author(s):  
M. Spector ◽  
A. C. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ectodermal Dysplasia ◽  
Ion Beam ◽  
Freeze Fracture ◽  
Ion Current ◽  
Ion Beam Etching ◽  
Pili Torti ◽  
Argon Ion ◽  
Scanning Electron

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.

Scanning Electron Microscopy of Staphylococcus Epidermidis Adherence to Continuous Ambulatory Peritoneal Dialysis Catheters

1985 ◽  
Vol 43 ◽  
pp. 520-521
Author(s):  
William J. Lamoreaux ◽  
David L. Smalley ◽  
Larry M. Baddour ◽  
Alfred P. Kraus
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Peritoneal Dialysis ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Staphylococcus Epidermidis ◽  
Sterile Saline ◽  
Intravascular Devices ◽  
Capd Patient ◽  
Scanning Electron

Infections associated with the use of intravascular devices have been documented and have been reported to be related to duration of catheter usage. Recently, Eaton et al. reported that Staphylococcus epidermidis may attach to silastic catheters used in continuous ambulatory peritoneal dialysis (CAPD) treatment. The following study presents findings using scanning electron microscopy (SEM) of S. epidermidis adherence to silastic catheters in an in vitro model. In addition, sections of polyvinyl chloride (PVC) dialysis bags were also evaluated by SEM.The S. epidermidis strain RP62A which had been obtained in a previous outbreak of coagulase-negative staphylococcal sepsis at local hospitals was used in these experiments. The strain produced surface slime on exposure to glucose, whereas a nonadherent variant RP62A-NA, which was also used in these studies, failed to produce slime. Strains were grown overnight on blood agar plates at 37°C, harvested from the surface and resuspended in sterile saline (0.85%), centrifuged (3,000 rpm for 10 minutes) and then washed twice in 0.1 M phosphate-buffered saline at pH 7.0. Organisms were resuspended at a concentration of ca. 106 CFU/ml in: a) sterile unused dianeal at 4.25% dextrose, b) sterile unused dianeal at 1.5% dextrose, c) sterile used dialysate previously containing 4.25% dextrose taken from a CAPD patient, and d) sterile used dialysate previously containing 1.5% dextrose taken from a CAPD patient.

scholarly journals Correlative In Vivo 2 Photon and Focused Ion Beam Scanning Electron Microscopy of Cortical Neurons

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e57405 ◽  
Author(s):  
Bohumil Maco ◽  
Anthony Holtmaat ◽  
Marco Cantoni ◽  
Anna Kreshuk ◽  
Christoph N. Straehle ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cortical Neurons ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Scanning ◽  
Scanning Electron

scholarly journals U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

2016 ◽  
Author(s):  
Ramprashad Prabhakaran ◽  
Vineet V. Joshi ◽  
Mark A. Rhodes ◽  
Alan L. Schemer-Kohrn ◽  
Anthony D. Guzman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sample Preparation ◽  
Scanning Electron

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.

The Fracture Failure Analysis of Precision Centrifuge Spindle

2014 ◽  
Vol 971-973 ◽  
pp. 802-805
Author(s):  
Wei Feng Zhang ◽  
Li Yan ◽  
Fu Xia Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Fracture Mechanics ◽  
Failure Analysis ◽  
Fatigue Failure ◽  
High Speed ◽  
Experimental Results ◽  
Fracture Failure ◽  
Scanning Electron

For the problem of high-speed rotating centrifuge spindle fracture failures, relevant analyses are conducted from the perspective of microstructure, chemical composition and fracture mechanics by using scanning electron microscopy and related instruments. Experimental results and analyses indicate that the spindle fracture is fatigue failure, mainly caused by cold cracks generated on the journal surfacing. Based on the analysis results, improvements and measures are suggested to better solve the spindle weld fracture failure problems.

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