bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhanced scanning control in a confocal scanning laser microscope
Authors: Trepte Oliver 
Published: June 2010

AbstractA fast and flexible scanning unit, allowing scanning rates of more than 1 kHz over regions identified in a specimen, has been developed and evaluated. This scanning unit replaces the original scanning unit in the Phoibos confocal scanning laser microscope and features full backward compatibility, while at the same time allowing fast and flexible scanning modes, such as point scanning, line scanning, and scanning along user‐selected closed curves. The scanning unit uses two galvanometer‐mounted mirrors for scanning. A standard procedure for recordings with this scanning unit would be to scan an overview image with conventional raster scanning to identify a region of interest, mark a point, a line, or a closed curve over this region, and to start the scanner. An iterating algorithm then calculates the waveforms needed by the scanner to follow the identified curves with pixel precision. With this scanning unit and its controlling software, experiments demanding time‐resolved recordings within the millisecond range can be performed. Repetition rates up to > 1 kHz for line scanning and curve scanning, and > 100 kHz for point scanning are obtainable. This allows time‐resolved studies of fast reactions in living tissue to be performed with the spatial resolution and signal‐to‐noise ratio obtainable with a point scanning confocal microscope.
Effects of gas pressure on low‐pressure electron‐beam lithography
Authors: Paul B. K. 
Published: June 2010

AbstractIn electron‐beam (EB) lithography, it is common practice to prepare the resist for exposure using a metal over‐layer or an ion shower to eliminate the charging of the resist. Recent efforts to prototype micromechanical structures using EB lithography methods have avoided the need for resist preparation by using low‐pressure EB lithography methods. While a great deal of research has centered around high‐vacuum electron‐beam (EB) lithography, little research has been conducted concerning the effect of gas chamber pressure on linewidth in low‐pressure EB lithography. In this paper, experimental data are presented linking the gas pressure in low‐pressure EB lithography with lithography line profiles. The results show that as gas pressure is varied, a compromise exists between line broadening and the charging‐up effect.
Transmission electron microscopy and scanning force microscopy of poly r(A‐U) and poly r(A‐U)‐ethidium bromide
Authors: Gilloteaux J. , Jamison J. M. , Zenhausern F. , Adrian M. , Summers J. L. 
Published: June 2010

AbstractTransmission electron microscopy and scanning force microscopy of negative‐stained, carbon‐coated replica and mica‐adsorbed preparations of 200 μM poly r(A‐U) and 50 μM ethidium bromide/200 μM poly r(A‐U) have been employed to evaluate ethidium‐induced changes in poly r(A‐U) topology. Poly r(A‐U) alone exhibits elongated conformations 85–115 nm in length that possess a number of hairpin loops as well as single‐stranded domains. While the double‐stranded domains are found predominately at the base of the hairpin loops (diameter = 5–30 nm), other rod‐like (presumably double‐stranded) regions ranging from 25–80 nm in length are present in other portions of the poly r(A‐U). In contrast with the poly r(A‐U) alone, the EB/poly r(A‐U) combination appears as a heterogeneous population of condensed structures whose lengths and widths vary from 12–88 nm and 15–45 nm, respectively. These conformational changes are due to a number of factors, including the displacement of ordered water surrounding the poly r(A‐U) and charge shielding of the phosphate groups of the poly r(A‐U) upon the binding of the ethidium.
A robust focusing and astigmatism correction method for the scanning electron microscope
Authors: Ong K. H. , Phang J. C. H. , Thong J. T. L. 
Published: June 2010

AbstractThis paper discusses a new approach to focusing and astigmatism correction based on the fast fourier transforms (FFTs) of scanning electron microscopy (SEM) images. From the FFTs, it is possible to obtain information on the severity of the defocus and astigmatism. This information is then processed by an algorithm to perform real‐time focusing and astigmatism correction on the SEM. The algorithm has been tested on defocused and astigmatic images of different samples, including those with highly directional features. Experiments show that the images obtained after running the algorithm can be as good as those that an experienced SEM operator can achieve.
Monte carlo simulation of charging effects in linewidth metrology (II): On insulator substrate
Authors: Ko Yeong‐Uk , Chung Myung‐Sae 
Published: June 2010

AbstractCharging effects have been investigated quantitatively using Monte Carlo (MC) simulation when the linewidth of polymethylmethacrylate (PMMA) insulator patterns on SiO2 insulator substrate are measured by scanning electron microscope (SEM). We established reference operating and shape conditions for array patterns and we have calculated the offset on linewidth metrology according to the change in each condition. We have used a 50% threshold algorithm for the edge determination, calculated the offsets in those conditions, and compared them with the results in the case of Si substrate. Finally, the question of which factor is the most sensitive in linewidth metrology is discussed.
Evaluation of cyanoacrylate glues for making attached living‐leaves epidermis replicas and its scanning electron microscopy observations (evaluación de pegamentos de cianoacrilato para hacer réplicas epidérmicas en hojas vivas adheridas y su observación al MEB)
Authors: Castilloa Juan Jose , Ferrarotto Maria 
Published: June 2010

AbstractSix brands of cyanoacrylate glue were tested to make inverse replicas of a leaf's epidermis. All of them gave satisfactory results for observations up to 8000x with a Philips XL‐20 scanning electron microscope (SEM), working at 10 kV. Genus of plants used were Xanthosoma sp., Psidium sp., Melicocca sp., Sorghum sp., and Stenotaphrum sp. The main limitations were that the epicuticular wax gets embedded within the glue. Spindle‐ or oval‐shaped artifacts are produced by stomatal apertures. This paper confirms previous findings related to the fact that cyanoacrylate glues are an alternative method for making fast, inexpensive, and sturdy epidermis replicas for scanning electron microscopy observation.
Cancer cell necrosis by autoschizis: Synergism of antitumor activity of vitamin C: Vitamin K3 on human bladder carcinoma T24 cells
Authors: Gilloteaux J. , Jamison J. M. , Arnold D. , Ervin E. , Eckroat L. , Docherty J. J. , Neal D. , Summers J. L. 
Published: June 2010

AbstractScanning and transmission electron microscopy and fluorescence light microscopy were employed to characterize the cytotoxic effects of vitamin C (VitC), vitamin K3 (VitK3) or a VitC:VK3 combination on a human bladder carcinoma cell line (T24) following 1‐h and 2‐h vitamin treatment. T24 cells exposed to VitC alone exhibited membranous damage (blebs and endoplasmic extrusions, elongated microvilli). VitK3‐treated cells displayed greater membrane damage and enucleation than those treated with VitC as well as cytoplasmic defects characteristic of cytoskeletal damage. VitC:VitK3‐treated cells showed exaggerated membrane damage and an enucleation process in which the perikarya separate from the main cytoplasmic cell body by self‐excision. Self‐excisions continued for perikarya which contained an intact nucleus surrounded by damaged organelles. After further excisions of cytoplasm, the nuclei exhibited nucleolar segregation and chromatin decondensation followed by nuclear karryorhexis and karyolysis. This process of cell death induced by oxidative stress was named autoschizis because it showed both apoptotic and necrotic morphologic characteristics.
The scanning low‐energy electron microscope: First attainment of diffraction contrast in the scanning electron microscope
Authors: Frank L. , Müllerová I. , Faulian K. , Bauer E. 
Published: June 2010

AbstractUsing small Pb crystals deposited in situ on a partially contaminated Si (100) crystal, we demonstrate that a commercial scanning electron microscope (SEM) can easily be converted into a scanning low‐energy electron microscope (SLEEM). Although the contrast mechanism is much more complicated than that in nonscanning LEEM because not only one diffracted monochromatic beam and its close environment are used for imaging, but several diffracted beams and a wide energy spectrum of electrons of different origin (secondary electrons, inelastically andelastically scattered electrons) are used, SLEEM is a valuable addition to the standard SEM because it provides an additional structure‐ and orientation‐sensitive contrast mechanism in crystalline materials, a low sampling depth, and high intensity at low energies.
Confocal laser scanning microscopy of hamster cerebellum using FM4‐64 as intracellular staining
Authors: Castejón O. , Sims P. 
Published: June 2010

AbstractThe FM4‐64, a member of the family of fluorescent dyes, has been applied to the cerebellar cortex to evaluate its properties as an intracellular stain and intracortical tracer. Slabs of hamster cerebellum, 1–2 mm thick, were incubated in 10, 30, and 100 μm solutions of FM4–64 in sodium phosphate buffer and observed in a slow scan confocal laser scanning microscope. Mossy and climbing fibers were traced in the cerebellar white and gray substances. They exhibited a high fluorescence signal at the level of the myelin sheath. Mossy fibers were identified in the granular layer by their typical rosette formation and dichotomous bifurcation pattern. Climbing fiber bundles were observed crossing the granular layer and giving collateral branches around Golgi cell bodies. They ascend to the Purkinje cell layer on their way to the molecular layer. Cerebellar macroneurons (Golgi and Purkinje cells) and microneurons (granule, basket, and stellate cells) showed optimal intracellular staining of cell soma, axonal, and dendritic processes. The z‐series of stacks of optodigital sections allowed us to explore in depth the cytoarchitectonic arrangement, nerve and glial cell morphology, and the topographic relationship with the afferent fibers.
Tilt dependence of the secondary electron emission at low excitation energy
Authors: Libinson A. G. 
Published: June 2010

AbstractInfluence of the specimen's slope on the secondary electron emission has been experimentally studied. Strong deviations from the inverse cos law have been observed and corresponding phenomenological equation (taking into account this deviation) is suggested. The consequences of the dependence on the topography contrast of low‐ and high‐voltage scanning electron microscopy (SEM) image, especially for three‐dimensional (3‐D) reconstruction, are considered.
Correlative light and backscattered electron microscopy of bone—Part I: Specimen preparation methods
Authors: Goldman Haviva M. , Kindsvater John , Bromage Timothy G. 
Published: June 2010

AbstractA method for preparing nondecalcified bone and tooth specimens for imaging by both light microscopy (LM) and backscattered electron microscopy in the scanning electron microscope (B SE‐SEM) is presented. Bone blocks are embedded in a polymethylmethacrylate (PMMA) mixture and mounted on glass slides using components of a light‐cured dental adhesive system. This method of slide preparation allows correlative studies to be carried out between different microscopy modes, using the same histologic section. It also represents a large time savings relative to other mounting methods whose media require long cure times.
Time‐lapse scanning electron microscopy for measurement of contamination rate and stage drift
Authors: Vladár András E. 
Published: June 2010

AbstractMeasurements done with scanning electron microscopes (SEMs) may lose their validity due to contamination and charging caused by the primary electron beam. The sample stage and the electron beam also slightly drift during the course of the measurements. Consequently, it is essential to find out the time limit of valid measurements, that is, the maximum time before the sample or its position changes too much.This paper describes digital time‐lapse SEM, a useful tool for investigating the extent and effects of contamination and stage drift. It works with hardware and software that create a stack of sequential images. Later these images can be viewed as a short movie; it is also possible to apply all the image processing and analysis procedures that are otherwise applied to separate, individual images.This method gives a reliable way of measuring the rate of contaminant deposition and of stage and electron beam drift of SEMs, and it could be helpful in controlling these problems.
A structural study of the bovine vaginal fluid at estrus
Authors: Rutllant J. , López‐Gatius F. , Camon J. , López‐Béjar M. , López‐Plana C. 
Published: June 2010

AbstractThe present study describes the structural components of the bovine vaginal fluid at estrus by scanning electron microscopy (SEM) following critical point‐ and freezedrying preparation procedures. Confocal scanning laser microscopy (CLSM) was also used to evaluate the structural integrity of samples, and a control sample was assessed by adding sperm to the vaginal fluid. Samples were collected from 10 cows at the time of artificial insemination, prepared for SEM by using critical point‐ and freeze‐drying procedures, gold coated, and observed by SEM. Mesh size and filament thickness were measured with an image analyzer. Of the 10 samples processed, 4 were considered altered following critical point drying. Compaction and lack of filaments were observed in these samples. A small area of one sample showed a honey comb‐like structure when freeze drying was used. Nonoriented filaments with different thicknesses and with a network‐like structure were observed throughout the remainder of the samples. Filaments throughout all samples were also observed by CSLM. After critical point drying, the mesh area ranged from 0.8 to 101.4 μm2; the minor axis from 0.7 to 10.8 μm; and filament thickness from 40 to 442 nm. Using freeze drying, the mesh area ranged from 0.9 to 493.8 μm2; the minor axis from 0.7 to 27.5 μm; and filament thickness from 40 to 800 nm. When samples were freeze dried, mesh values were similar to the interstrand channels observed by CSLM. In sperm‐vaginal fluid samples, following critical point‐ or freeze‐drying procedures, spermatozoa were oriented randomly in the vaginal fluid and did not seem to alter filamentous structure. Our data suggest that the freeze‐drying procedure better preserves the true structural dimensions of the vaginal fluid. Furthermore, the filamentous structure of the vaginal fluid does not appear to impede sperm transport.
Crystallographic orientation assessment by electron backscattered diffraction
Authors: Cléton F. , Jouneau P. H. , Henry S. , Gäumann M. , Buffat P. A. 
Published: June 2010

AbstractWith an angular orientation accuracy of at least 1°, the ability of electron backscattered diffraction (EBSD) to determine and emphasise crystallographic orientation is illustrated. Using the abilities of specially developed software for computing Euler angles derived from the scanned specimen, misorientations are pointed out with acceptable flexibility and graphic output through crystallographic orientation maps or pole figures. This ability is displayed in the particular case of laser cladding of nickel‐based superalloy, a process that combines the advantages of a near net‐shape manufacturing and a close control of the solidification microstructure (E‐LMF: epitaxial laser metal forming).
Three‐dimensional reconstruction of fracture surfaces: Area matching algorithms for automatic parallax measurements
Authors: Hein Luis Rogerio de Oliveira , Silva Fernando de Azevedo , Nazar Ana Maria Martinez , Ammann Jean Jacques 
Published: June 2010

AbstractThis paper describes two solutions for systematic measurement of surface elevation that can be used for both profile and surface reconstructions for quantitative fractography case studies. The first one is developed under Khoros graphical interface environment. It consists of an adaption of the almost classical area matching algorithm, that is based on cross‐correlation operations, to the well‐known method of parallax measurements from stereo pairs. A normalization function was created to avoid false cross‐correlation peaks, driving to the true window best matching solution at each region analyzed on both stereo projections. Some limitations to the use of scanning electron microscopy and the types of surface patterns are also discussed. The second algorithm is based on a spatial correlation function. This solution is implemented under the NIH Image macro programming, combining a good representation for low contrast regions and many improvements on overall user interface and performance. Its advantages and limitations are also presented.
A study of electron beam‐induced conductivity in resists
Authors: Hwu J. J. , Joy D. C. 
Published: June 2010

AbstractThe charging of polymeric resist materials during electron beam irradiation leads to significant problems during imaging and lithography processes. Charging occurs because of charge deposition in the polymer and charge generation/trapping due to formation of electron‐hole pairs in the dielectric. The presence of such charge also results in the phenomena of electron beam‐induced conductivity (EBIC). Electron beam‐induced conductivity data have been obtained for three commercial e‐beam resists under a variety of dose rate and temperature conditions. From the observed values of induced conductivity under varying conditions significant information about the generation of electron‐hole pair and the transport of charge in the resist can be obtained. Three electron beam resists, EBR900, ZEP7000, and PBS are examined by an external bias method. The difference in resist chemistry is considered to play the role in the initial state EBIC behaviors among three resists even though the way that it affects the behaviors is not clear. A comparison of the power consumption comparison is proposed as a measure to give a preliminary estimate of the carrier concentration and carrier drift velocity differences among the resists. A simple single trap model with constant activation energy is proposed and provides good agreement with experiment.
Using atomic force microscopy to probe food biopolymer functionality
Authors: Morris V. J. , Kirby A. R. , Gunning A. P. 
Published: June 2010

AbstractAtomic force microscopes (AFMs) generate images by “feeling” rather than “looking” at samples. This permits a magnification range spanning that associated with both the light and electron microscopes, but under the “natural” imaging conditions normally associated with light microscopes. Molecules and molecular interactions can be imaged at molecular or submolecular resolution in gaseous or liquid environments. By careful design of experiments it is possible to use AFM to probe how food biopolymers determine the structure and texture of food products. This approach will be illustrated through studies on food polysaccharides and proteins.
Morphologic changes of starch granules in the apple cv. Mutsu during ripening and storage
Authors: Kovács Etelka , Eads T. M. 
Published: June 2010

AbstractUnripe (A), semiripe (B), and ripe (C) apples (Malus domestica cv. Mutsu) stored (2–4 °C, 90–95% RH) for 1 week were studied. The decrease in the starch content was as a function of storage time and ripeness.The size (area, perimeter and circularity) of starch granules was determined by image analyzer (Semper6, Synoptics) interfaced with a standard light microscope (Olympus, BH2) using a bright field illumination. Area (Ar) (larger than 100 pixel), perimeter (Pe), and circularity (Ci) of the granules were measured. The distribution of Ar, Pe, and Ci was calculated by the Distribution Fitting Statistical program; normality of frequency distribution of data (Chi‐square test), average ± standard deviation, t‐values were presented. All data were analyzed by principal component analysis.Area and perimeter decreased, circularity increased with the storage time and ripeness. Critical differences were observed in the semiripe apple cortex (CoB0) and the ripe apple skin (SC0) compared with the other samples (unripe skin and cortex) at the harvest. In both samples, most starch granules swelled (19–24%), and the starch contents were significantly less than in others. The stage of ripeness could be more exactly followed by image analysis than by the starch iodine test, or the color of apple skin.The ultrastructure (SEM) of starch did show typical changes as a function of storage time. More smaller starch granules could be seen in the stored apples than in the fresh ones. Damaged (pits, cavities) starch granules were found in all samples.Carbon‐13 NMR spectra of isolated apple cortex starch were obtained with cross polarization (CP), magic angle spinning (MAS), and high power proton irradiation (HD). There were shoulders on the C‐1 resonance and on the C‐2, 3, 4, 5 cluster. These shoulders indicate the presence of amorphous starch.
Edible starch films and coatings characterization: scanning electron microscopy, water vapor, and gas permeabilities
Authors: García María A. , Martino Miriam N. , Zaritzky Noemí E. 
Published: June 2010

AbstractEffects of coating formulation (starch type and plasticizer) on microstructure, water vapor, and gas permeabilities of films and coatings were analyzed. Plasticizer addition was necessary for films and coatings integrity to avoid pores and cracks. A satisfactory correlation between microstructure observations by scanning electron microscopy, electronic thickness measurements, and water vapor and gas permeability determinations was observed. Films and coatings with high amylose content starches showed lower water vapor and gas permeabilities compared with films and coatings with medium amylose content starches. Films and coatings with sorbitol showed lower water vapor and gas permeabilities than those with glycerol, with the most effective plasticizer concentration being 20 g/l.
Comparison of different models for the generation of electron backscattering patterns in the scanning electron microscope
Authors: Wells Oliver C. 
Published: June 2010

AbstractAn electron backscattering pattern (EBSP) is formed on a fluorescent (or other) screen from the faster scattered electrons when a single‐crystal region of a solid sample is illuminated by a finely focused electron beam (EB). The EBSP is very similar in appearance to the electron channeling pattern (ECP) that is obtained in the scanning electron microscope (SEM) by rocking the beam about a point on the surface of a single crystal. It has been suggested that the mechanisms that give rise to EBSP and ECP are related by reciprocity. If this is indeed the case, then the models that are used to explain them should be the same except for the direction in which the electrons travel through the specimen. The two‐event “diffraction model” for EBSP (diffuse scattering followed by diffraction) fails this condition, leading to the conclusion that the “channeling in and channeling out” model for EBSP is more likely to be correct. This has been described rigorously by Reimer (1979, 1985). It is named after the title used by Joy (1994). An attempt is made here to describe this model in a simple way.