scholarly journals Nanomechanical Subsurface Characterisation of Cellulosic Fibres

2021 ◽  
Author(s):  
Julia Auernhammer ◽  
Markus Langhans ◽  
Jan-Lukas Schäfer ◽  
Tom Keil ◽  
Tobias Meckel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Three Dimensions ◽  
Confocal Laser ◽  
Subsurface Imaging ◽  
Microscopy Imaging ◽  
Paper Production ◽  
Carbohydrate Binding Modules ◽  
Cellulosic Fibres

Abstract The mechanical properties of single fibres are highly important in the paper production process to produce and adjust properties for the favoured fields of application. The description of mechanical properties is usually characterised via linearized assumptions and is not resolved locally or spatially in three dimensions. In tensile tests or nanoindentation experiments on cellulosic fibres, only one mechanical parameter, such as elastic modulus or hardness, is usually obtained. To obtain a more detailed mechanical picture of the fibre, it is crucial to determine mechanical properties in depth. To this end, we discuss an atomic force microscopy-based approach to examine the local stiffness as a function of indentation depth via static force-distance curves. This method has been applied to linter fibres (extracted from a finished paper sheet) as well as to natural raw cotton fibres to better understand the influence of the pulp treatment process in paper production on the mechanical properties. Both types of fibres were characterised in dry and wet conditions with respect to alterations in their mechanical properties. Subsurface imaging revealed which wall in the fibre structure protects the fibre against mechanical loading. Via a combined 3D display, a spatially resolved mechanical map of the fibre interior near the surface can be established. Additionally, we labelled fibres with carbohydrate binding modules tagged with fluorescent proteins to compare the AFM results with fluorescence confocal laser scanning microscopy imaging. Nanomechanical subsurface imaging is thus a tool to better understand the mechanical behaviour of cellulosic fibres, which have a complex, hierarchical structure.

scholarly journals Use of electromagnetic stimulation on an Enterococcus faecalis biofilm on root canal treated teeth in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz H. D. Panariello ◽  
Justin K. Kindler ◽  
Kenneth J. Spolnik ◽  
Ygal Ehrlich ◽  
George J. Eckert ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Laser Scanning ◽  
Confocal Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Imaging ◽  
Electromagnetic Stimulation ◽  
Root Canal Disinfection

AbstractRoot canal disinfection is of utmost importance in the success of the treatment, thus, a novel method for achieving root canal disinfection by electromagnetic waves, creating a synergistic reaction via electric and thermal energy, was created. To study electromagnetic stimulation (EMS) for the disinfection of root canal in vitro, single rooted teeth were instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with Enterococcus faecalis ATCC 29,212, which grew for 15 days to form an established biofilm. Samples were treated with 6% sodium hypochlorite (NaOCl), 1.5% NaOCl 1.5% NaOCl with EMS, 0.9% saline with EMS or 0.9% saline. After treatments, the colony forming units (CFU) was determined. Data was analyzed by Wilcoxon Rank Sums Test (α = 0.05). One sample per group was scored and split for confocal laser scanning microscopy imaging. There was a significant effect with the use of NaOCl with or without EMS versus 0.9% saline with or without EMS (p = 0.012 and 0.003, respectively). CFUs were lower when using 0.9% saline with EMS versus 0.9% saline alone (p = 0.002). Confocal imaging confirmed CFU findings. EMS with saline has an antibiofilm effect against E. faecalis and can potentially be applied for endodontic disinfection.

scholarly journals Reconstruction of Axial Tomographic High Resolution Data from Confocal Fluorescence Microscopy: A Method for Improving 3D FISH Images

2000 ◽  
Vol 20 (1) ◽  
pp. 7-15 ◽  
Author(s):  
R. Heintzmann ◽  
G. Kreth ◽  
C. Cremer
Keyword(s):  
High Resolution ◽  
Laser Scanning ◽  
Axial Direction ◽  
Laser Scanning Microscopy ◽  
Three Dimensions ◽  
Confocal Laser ◽  
Data Sets ◽  
Data Set ◽  
High Resolution Data ◽  
3D Data

Fluorescent confocal laser scanning microscopy allows an improved imaging of microscopic objects in three dimensions. However, the resolution along the axial direction is three times worse than the resolution in lateral directions. A method to overcome this axial limitation is tilting the object under the microscope, in a way that the direction of the optical axis points into different directions relative to the sample. A new technique for a simultaneous reconstruction from a number of such axial tomographic confocal data sets was developed and used for high resolution reconstruction of 3D‐data both from experimental and virtual microscopic data sets. The reconstructed images have a highly improved 3D resolution, which is comparable to the lateral resolution of a single deconvolved data set. Axial tomographic imaging in combination with simultaneous data reconstruction also opens the possibility for a more precise quantification of 3D data. The color images of this publication can be accessed from http://www.esacp.org/acp/2000/20‐1/heintzmann.htm. At this web address an interactive 3D viewer is additionally provided for browsing the 3D data. This java applet displays three orthogonal slices of the data set which are dynamically updated by user mouse clicks or keystrokes.

scholarly journals Silencing cuticular pigmentation genes enables RNA FISH in intact chemosensory appendagess

2018 ◽  
Author(s):  
Stefan Pentzold ◽  
Veit Grabe ◽  
Andrei Ogonkov ◽  
Lydia Schmidt ◽  
Wilhelm Boland ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Imaging ◽  
Leaf Beetles ◽  
Antisense Mrna ◽  
Rna Fish ◽  
Whole Mount ◽  
Light Absorbance ◽  
Odorant Binding

AbstractOptical imaging of gene expression by RNA-fluorescent in situ hybridisation (FISH) in whole-mount sensory appendages of insects is often impeded by their highly pigmented cuticle. Since most chemical bleaching agents are incompatible with imaging fluorescent-labelled nucleotides, we developed a RNA interference-based method for clearing cuticular pigmentation that allows imaging of fluorescent mRNA in whole-mount appendages of insects. Silencing key genes of the tyrosine-derived pigmentation pathway by injecting dsRNA of laccase2 or tyrosine hydroxylase in two leaf beetles species (Chrysomela populi, Phaedon cochleariae) resulted in clearance of the highly pigmented cuticle and in significant decreased light absorbance. Intact chemosensory appendages (palps, antennae and legs) from RNAi-cleared individuals were used to image expression and spatial distribution of antisense mRNA of two chemosensory genes (gustatory receptor, odorant-binding protein) via RNA FISH and confocal laser scanning microscopy. Imaging of these genes did neither work for RNAi-controls (dsGfp) due to retained pigmentation, nor for FISH-controls using sense mRNA. Furthermore, we show that several chemical bleaching agents are not feasible with FISH, either due to significant degradation of polynucleotides, lack of clearing efficacy or long incubation times. Overall, silencing pigmentation genes is a significant improvement over bleaching agents allowing fluorescence imaging in whole-mount appendages and organs.

scholarly journals Orientation-Dependent Deformation Behavior of 316L Steel Manufactured by Laser Metal Deposition and Casting under Local Scratch and Indentation Load

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1765
Author(s):  
Fabian Pöhl ◽  
Corinna Hardes ◽  
Felicitas Scholz ◽  
Jan Frenzel
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Laser Scanning ◽  
Local Deformation ◽  
Metal Deposition ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Laser Metal Deposition ◽  
Stainless Steel 316L ◽  
Longitudinal Specimen

This study analyzes the local deformation behavior of austenitic stainless steel 316L, manufactured conventionally by casting and additively by laser metal deposition (LMD). We produced directionally solidified 316L specimens with most grains showing (001) orientations parallel to the longitudinal specimen axis. We conducted nanoindentation and scratch experiments for local mechanical characterization and topography measurements (atomic force microscopy and confocal laser scanning microscopy) of indentation imprints and residual scratch grooves for the analysis of the deformation behavior and, in particular, of the pile-up behavior. The local mechanical properties and deformation behavior were correlated to the local microstructure investigated by scanning electron microscopy with energy dispersive X-ray spectroscopy and electron backscatter diffraction analysis. The results show that the local mechanical properties, deformation behavior, and scratch resistance strongly depend on the crystallographic orientation. Nearly (001)-oriented grains parallel to the surface show the lowest hardness, followed by an increasing hardness of nearly (101)- and (111)-oriented grains. Consequently, scratch depth is the greatest for nearly (001)-oriented grains followed by (101) and (111) orientations. This tendency is seen independently of the analyzed manufacturing route, namely Bridgman solidification and laser metal deposition. In general, the laser metal deposition process leads to a higher strength and hardness, which is mainly attributed to a higher dislocation density. Under the investigated loading conditions, the cellular segregation substructure is not found to significantly and directly change the local deformation behavior during indentation and scratch testing.

Confocal laser scanning microscopy and Raman imagery of the late Neoproterozoic Chichkan microbiota of South Kazakhstan

2010 ◽  
Vol 84 (3) ◽  
pp. 402-416 ◽  
Author(s):  
J. William Schopf ◽  
Anatoliy B. Kudryavtsev ◽  
Vladimir N. Sergeev
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Three Dimensions ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Depth Study ◽  
Late Neoproterozoic

Precambrian microbiotas, such as that permineralized in bedded and stromatolitic cherts of the late Neoproterozoic, 750- to 800-Ma-old, Chichkan Formation of South Kazakhstan, have traditionally been studied by optical microscopy only. Such studies, however, are incapable of documenting accurately either the three-dimensional morphology of such fossils or their chemical composition and that of their embedding minerals. As shown here by analyses of fossils of the Chichkan Lagerstätte, the solution to these long-standing problems is provided by two techniques recently introduced to paleontology: confocal laser scanning microscopy (CLSM) and Raman imagery. The two techniques are used together to characterize, in situ and at micron-scale resolution, the cellular and organismal morphology of the thin section-embedded organic-walled Chichkan fossils. In addition, Raman imagery is used to analyze the molecular-structural composition of the carbonaceous fossils and of their embedding mineral matrix, identify the composition of intracellular inclusions, and quantitatively assess the geochemical maturity of the Chichkan organic matter.CLSM and Raman imagery are both broadly applicable to the study of fossils, whether megascopic or microscopic and regardless of mode of preservation, and both are non-intrusive and non-destructive, factors that permit their use for analyses of archived specimens. They are especially useful for the study of microscopic fossils, as is demonstrated in this first in-depth study of diverse taxa of a single Precambrian microbiota for which they provide information in three dimensions at high spatial resolution about their organismal morphology, cellular anatomy, kerogenous composition, mode of preservation, and taphonomy and fidelity of preservation.

Automated biofilm morphology quantification from confocal laser scanning microscopy imaging

2003 ◽  
Vol 47 (5) ◽  
pp. 31-37 ◽  
Author(s):  
J.B. Xavier ◽  
D.C. White ◽  
J.S. Almeida
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Imaging ◽  
Biofilm Structure ◽  
User Friendly ◽  
Processing Steps

In spite of the immediate visual appeal of confocal laser scanning microscopy images, the extraction of accurate reconstitutions of biofilm morphology requires a lengthy and computational intensive succession of processing steps. However, once performed, it provides ample reward by enabling the quantitative study of biofilm structure. A software suite of image processing tools for full automation of biofilm morphology quantification was developed by integrating preprocessing, segmentation and morphology quantification operations. This software toolbox was implemented in a web server and a user friendly interface was developed to facilitate image submission, storage and sharing, its access being unrestricted for scientific applications. The image bioinformatics tool which results from the integration of the processing operations can be accessed at http://www.itqb.unl.pt:1111/clsmip/. Its use is described in this paper and is illustrated with an example of processing of experimental data describing the growth of a mixed species denitrifying biofilm.

The furfuryl alcohol (FA) resin distribution in the furfurylated bamboo

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wanju Li ◽  
Minghui Liu ◽  
Hankun Wang ◽  
Hongbo Zhai ◽  
Yan Yu
Keyword(s):  
Furfuryl Alcohol ◽  
Laser Scanning ◽  
Parenchymal Cell ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Sem Images ◽  
Microscopy Imaging ◽  
Resin Impregnation ◽  
Specific Distribution ◽  
Ft Ir

AbstractIt is well known the properties of resin impregnation wood is significantly influenced by the specific distribution pattern of resin in the modified wood. In this work, bamboo was furfurylated with an improved process. In addition to testing and evaluating its main physical, mechanical and durable properties, it was explored how the furfuryl alcohol (FA) resin is distributed in the furfurylated bamboo. To achieve this goal, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), nanoindentation, and imaging Fourier transform infrared microscopy (imaging FT-IR) were applied. SEM images demonstrates FA resin is mainly located in the parenchymal cell cavity of bamboo, however the existence of FA resin in the small cavities of the bamboo fibers is also observed by CLSM. In addition, the result of nanoindentation and imaging FT-IR both indicates that FA can penetrate and polymerize within the cell wall of the bamboo fiber. It is then concluded the heterogeneous but multi-scale distribution of FA resin should be responsible for the significant improvement of furfurylated bamboo in both dimensional stability and biological durability.

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