bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycerol Permeabilization of Fluorescently-Labeled Phalloidin Improves Actin Visualization in Vibratome-Sectioned Roots
Authors: Blancaflor EB , Hasenstein KH 
Published: July 2020

Abstract
The actin cytoskeleton is involved in various cellular functions including cell shape determination, organelle transport, and cell polarity establishment. In order to study the function and dynamics of actin in plant cells, methods to image its orientation have to be optimized. Although, green fluorescent proteins (GFP) from the jellyfish Aequoria victoria have been used for visualizing actin filaments in plant cells, the technique is still in its infancy and has some limitations. Actin in plant cells is difficult to preserve and hence visualize mainly because of the problems associated with specimen fixation and processing. This is particularly true for bulky specimens such as plant organs because of the additional requirement for embedding and sectioning after the tissues are fixed and dehydrated. In order to overcome these difficulties, we have modified a method previously used for onion epidermal cells and suspension cells, and applied this to fresh Vibratome sectioned root tissues.
Visualization of Uptake of High-Density Lipoprotein by Rat Aortic Endothelial Cells and Smooth Mus.Cle Cells in Vitro
Authors: Chao W T , Yang V C 
Published: July 2020

Abstract
The high concentration of low-density lipoprotein in the plasma is the major risk factor of atherosclerosis. On the other hand, another plasma lipoprotein—high-density lipoprotein (HDL) — is inversely correlated with atherosclerosis. Recent studies have demonstrated that HDL mediates the transport of cholesterol from peripheral tissues to the liver through “reverse cholesterol transport” pathway. However there is considerable debate about the mechanisms by which HDL removes excess cholesterol from cells. Two different pathways were suggested: (i) a docking receptor promoting cholesterol translocation, or (ii) a receptor mediated intracellular endosomal pathway termed “retroendocytosis”. In the present study, we performed fluorescence and electron microscopy to visualize the uptake of HDL using cholesterol-load rat aortic endothelial and smooth muscle cells in vitro.
Endothelial and smooth muscle cells were obtained from rat aorta and cultured in medium under 5% CO2/ 95% air atmosphere. Then confluent monolayers of endothelial and smooth muscle cells were incubated in cholesterol or fluorescence-labeled cholesterol DMEM medium for 48 hr.
The Role of Superoxide and Nitric Oxide in the Development of Myocardial Injury in Rat Myocarditis.
Authors: Nishikawa T , Ishiyama S , Suzuki A , Masuda A , Kasajima T 
Published: July 2020

Abstract
The mechanism of myocardial injury in myocarditis is still unclear. Recently, nitric oxide (NO), massively produced in the inflammation, has been suggested to be harmful for tissue at excess amount as well as superoxide. However, it is still unclear the relationship between production of NO with superoxide and myocardial damage in myocarditis. In this study, we investigated whether NO and/or superoxide play an important role in the pathogenesis of myocardial injury in myocarditis.
The heart tissue specimens were taken from Lewis rats with experimentally induced myocarditis. Immunohistochemical staining was performed using polyclonal antibody for inducible NO synthase by avidin-biotin peroxidase complex method in paraffin sections of the tissue. Histochemical study for ultrastructural H2O2-producing site in the heart tissue was carried out by Brigg’ s method using CeCl3; briefly, the heart tissues were incubated in 0.1M Tris-malate buffer with ImM CeCl3 and 10mM aminotriazole. Then tissues were fixed in 2% glutaraldehyde, postfixed with 1% OsO4 and embedded in resin for electron microscopy.
Preparation of 3D Atom Probe Samples of Multilayered Film Structures using a Focused Ion Beam
Authors: Martens R L , Larson D J , Kelly T F , Cerezo A , Clifton P’H , Tabat N 
Published: July 2020

Abstract
Focused ion beam (FIB) instruments have become essential for the preparation of atom probe samples from heterogeneous materials. Previous sample preparation methods such as electropolishing are limited in their application due to either geometrical or electrochemical constraints. Recent developments in sample preparation using a FIB have enabled the production of AP samples from various materials and, more importantly, from non-traditional sample geometries that contain multilayered thin film structures (MLF).
Most sample preparation using a FIB first involves a sample that has been reduced in size through some manual sample preparation technique like tripod polishing or cutting. Smaller, thinner samples require less milling time in the FIB. A silicon wafer etched with the “Bosch” process was used to produce a surface that contains millions of 20, 16, 12, 8, and 4 μm square by -180 μrn long “posts”, Fig. 1. A multilayer film structure is deposited on the flat surface of the silicon posts in a standard deposition process.
Effects of Ion Species and Energy on the Amorphization of Si During FIB TEM Sample Preparation as Determined by Computational and Experimental Methods
Authors: Jamison R B , Mardinly A J , Susnitzky D W , Gronsky R 
Published: July 2020

Abstract
Gallium focused ion beam (FIB) milling is the method of choice to prepare cross sections of selected features from microelectronic devices for transmission electron microscope (TEM) imaging and analysis. The FIB milling technique is unsurpassed in producing an ultra-thin cross section accurately located through the feature of interest. While much effort has been invested in the development and refinement of Ga+ FIB techniques and instrumentation, there are problems due to the physics of the ion-solid interaction. The problem of surface amorphization limits the quality of the TEM samples and its significance increases as the feature size and the specimen thickness decrease.
In Ga+ FIB milling of silicon, the amorphous damage layer consists of amorphous Si doped with implanted Ga. This damage layer is caused by ions that strike the surface of the silicon and are subsequently scattered laterally as a result of collisions with the Si atoms.
Microstructural Characterization of Automated Specimen Preparation for TEM Analysis
Authors: Shannon C Urbanik , Giannuzzi L A , Raz E M 
Published: July 2020

Abstract
Automated specimen preparation for transmission electron microscopy has the obvious advantage of saving personnel time. While some people may perform labor intensive specimen preparation techniques quickly, automated specimen preparation performed in a timely and reproducible fashion can significantly improve the throughput of specimens in an industrial laboratory. The advent of focused ion beam workstations for the preparation of electron transparent membranes has revolutionized TEM specimen preparation. The FIB lift-out technique is a powerful specimen preparation method. However, there are instances where the “traditional” FIB method of specimen preparation may be more suitable. The traditional FIB method requires that specimens must be prepared so that the area of interest is as thin as possible (preferably less than 50 μm) prior to FIB milling. Automating the initial specimen preparation for brittle materials (e.g., Si wafers) may be performed using the combination of cleaving and sawing techniques as described below.
Focused Ion Beam Induced Copper Artifact Dose Study
Authors: Rossie BB , Anderson SD , Stevie FA , Brown SR , Shofner TL 
Published: July 2020

Abstract
Reduced feature dimensions in microelectronic devices has led to a growing reliance on the focused ion beam (FIB) for scanning electron microscopy (SEM) and transmission electron microscopy (TEM) specimen preparation. The introduction of copper for use in electrical interconnects will increase this reliance. Copper, much more so than aluminum, tends to smear when conventional polishing techniques are employed, rendering mechanical polishing unsuitable for quality specimen preparation.
The sputtering characteristics of copper differ greatly from the aluminum based materials currently in use. Copper exhibits a grain orientation dependent sputtering rate that tends to produce uneven FIB polished surfaces. The sputtering rate for copper is also much higher than the silicon and dielectric materials that must be simultaneously removed. These differences in sputtering rates lead to the formation of curtains and ledges that also affect specimen quality.
Another FIB induced artifact was observed when preparing SEM specimens (Figure 3).
TEM Specimen Preparation of Oxidized Ni-Base Alloys using the Focused Ion Beam (FIB) Technique
Authors: More KL , Coffey DW , Pint BA , Trent KS , Tortorelli PF 
Published: July 2020

Abstract
Microstructural characterization of thin alumina scales formed on oxidized Ni-base alloys using transmission electron microscopy (TEM) has long been a challenge as a result of the many problems encountered during the preparation of thin specimens. Successful and reproducible preparation of uniformly thin, cross-section TEM specimens from these multicomponent “layered” structures (alumina scale on a metallic substrate) is extremely difficult using standard ion beam thinning procedures for several reasons: (1) differential thinning of the various constituents in the system can occur, (2) a weak ceramic-metal interface may lead to separation during the harsh mechanical grinding and thinning procedure, (3) fully intact scales are rarely achieved since native surface structures are usually lost during ion milling, and (4) extensive damage can be created in the scale and alloy during rough grinding and polishing steps as well as during final ion beam thinning.
Dimensional and Angular Measurements from Microvascular Corrosion Casts: 2D vs. 3D
Authors: B. Minnich , R. Sommer , Lametschwandtner A 
Published: July 2020

Abstract
In microvascular network analysis on vascular corrosion casts (VCC) detection of vascular relations between distant regions within vascular territories deserves to operate the SEM at low magnification (&lt; 500x). As a result in low powered SEM micrographs of VCCs vessels may remain in the wide zone of focal depth (Dƒ), but can approach upper and lower focal planes of this zone (Fig.l). Their lengths, thus may severely be underestimated when measuring in 2D. The differences in lengths in 2D (L3D) and in 3D (L3D) of a distance L between points p1 and p2 (Fig.3) is obvious, denoting

While data from 2D-morphometry (1, 2, 3) have to be corrected for dimensional measurements in the direction of tilt by expanding the dimensions by [l/cos(tilt angle)] (4), modern 3D-morphometry techniques (5, 6, 7) consider the perspective projections by calculating the parallax in their working algorithms.
Tridimensional Characteristics of Rat Testicles Submitted to Tumour Cells Implant (Walker 256)
Authors: CHOPARD RP , LOURENCO MG , OCAÑA RP 
Published: July 2020

Abstract
The intention of this paper is to comparatively demonstrate the tridimensional architecture of the microvascularization and the pattern of the microvascularization of testicles submitted to tumour cells implant, considering that supporting mechanisms of cell vitality depend on the vascular array.
Testicles of 25 Wistar male rats were used. To proceed the implant of the tumour cells it was used a 50cc insulin syringe with short needle witch was introduced into the inferior apex of the organ. The animals were anaesthetised with 50% ethylic ether solution and 50% alcohol 96° by inhalation in proper chamber. The weight of the rats was verified every day to evaluate alterations due to tumour development and malignant evolution so it was possible to determine the exact day of sacrifice.
The perfusion was performed trough the abdominal part of the aorta using a needle connected to a silicon tube.
Electron Microscopic Analysis of Cerebral Aneurysms
Authors: Grove-Sullivan M , Yonas H , Watkins S 
Published: July 2020

Abstract
A cerebral aneurysm is a dome or sac-like structure budding from weakened arterial walls in the brain. Cerebral aneurysms have no known specific cause currently. Considering the risks of surgery, when surgery should be performed on unruptured aneurysms is a very controversial issue. Some clinicians feel that an aneurysm should be surgically removed immediately upon discovery regardless of the size, if surgery is possible. While others feel that small aneurysms should be watched or treated with endovascular insertion of soft platinum coils, avoiding the risks associated with any brain surgery. To further study this question examination was done of specimens from surgical clip ligation of middle cerebral artery aneurysms and normal specimens.
Specimens of ruptured and unruptured aneurysm as well as normal artery removed from surgical patients were immediately preserved in cold 2.5% glutaraldehyde in 0.1 M PBS. The specimens were rinsed in PBS, post-fixed in 1% Osmium Tetroxide with 0.1% potassium ferricyanide,
Effects of 2,2',4,4',5-Pentachlorobiphenyl on Mitochondria and Glycogen Mean Volume Fractions in Rat Hepatocytes
Authors: Gallant TL , Singh A 
Published: July 2020

Abstract
Detection of polychlorinated biphenyls (PCBs) in the environment in the late 1960s along with increasing scientific data on their detrimental health effects led to a voluntary ban on these chemicals for industrial uses except in closed systems such as dielectric fluids. Commercial mixtures of the chemicals were manufactured extensively from the mid-1950s to the 1970s for use as flame retardants, lubricants, and dielectric fluids. It was not until the late 1970s that the manufacture of PCBs ceased. Environmental contamination of PCBs, however, continues to be a pervasive problem because of their lipophilic nature and resultant bioaccumulation in the food chain. PCB 118 (2,3',4,4',5-pentachlorobiphenyi) is one member of the chemically inert group of compounds composed of 209 congeners, effects of which are described in current work as a quantitative analysis of hepatocyte ultrastructure using stereology techniques. We determined the mean volume fractions of mitochondria and glycogen particles in the liver cells following exposure of PCB 118 to weanling Sprague-Dawley rats.
Expression and Co-Localization of C-Type Natriuretic Peptide and Endothelin in Human Kidney
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Wei C , Burnett J C 
Published: July 2020

Abstract
C-type natriuretic peptide (CNP) is an endothelium-drived vasorelaxing factor which is present in human plasma, urine and renal epithelial cells. Endothelin (ET) is a potent renal and systemic vasoconstrictor and sodium regulating peptide. To date, the localization of C-type natriuretic peptide and endothelin gene expression in human kidney remains poorly defined.
We determined the co-localization of C-type natriuretic peptide and endothelin mRNA in normal human kidney using in situ hybridization (ISH) with synthesized human C-type natriuretic peptide or human endothelin oligonucleotide probes together with immunohistochemical staining (IHCS) with human CNP-22 and ET-1 antibodies with no crossreactivity. The sections treated with nonimmune rabbit serum (NRS) demonstrated no immunoperoxidase activity. Human renal tissue (n=7) was obtained from biopsy of normal cadaveric donor kidneys and normal autopsy specimens.
In situ hybridization (Figure 1) demonstrated that C-type natriuretic peptide and endothelin mRNA presence in human kidney which was localized to proximal and distal tubes with similar intensities.
Enhancement of Natriuretic Peptides in Rejected Human Renal Graft
Authors: Song H , Papadimitriou J , Drachenberg C , Weir M R , Wei C 
Published: July 2020

Abstract
Natriuretic peptides include atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP). ANP, BNP and CNP are structure related but genetic distinct 1 natriuretic peptide family. ANP and BNP are cardiac cell origin and CNP are endothelial cell and kidney origin. Natriuretic peptides have potent vasoactive and natriuretic actions through generation of cGMP. On the other hand, renal graft rejection is major problem after kidney transplantation with severe renal damage and renal vasoconstriction. We hypothesized that renal tissue level of natriuretic peptides increase in renal graft rejection through compensatory mechanism. Therefore, the present study was designed to determine the expression of natriuretic peptides by immunohistochemical staining (IHCS) in human renal tissue with rejection and compare with normal renal tissue.
Human renal biopsy (n=5) were obtained after kidney transplantation with mild and moderate renal rejection. Normal kidney biopsy was obtained during nephrectomy. ANP, BNP and CNP levels in renal tissue were determined by IHCS.
High Resolution Low Voltage Field Emission Scanning Electron Microscopy on De-Embedded Thick Sections Reveals Structural Interactions of the Surface of the Apicomplexan Parasite Toxoplasma Gondii with the Host Cell in the Parasitophorous Vacuole
Authors: Schatten Heide , Sibley David , Ris Hans 
Published: July 2020

Abstract
The protozoan parasite Toxoplasma gondii represents a large group of Apicomplexan parasites with a highly unusual motility system that is crucial for cell locomotion and host cell invasion. Studying the motility system and interactions with host cells will increase our knowledge on how to prevent infection. Apicomplexan parasites can cause considerable health problems to animals including sheep, goats, pigs, and chicken. Eimeria is known as a pathogen of coccidiosis in chicken, and Cryptosporidium causes cryptospiridiosis in cattle and other farm animals. Toxoplasma gondii can cause infection that results in abortion, central nervous disorders and death of stressed and immunocompromised farm animals. Common to all Apicomplexan parasites is an unconventional motility system that is thought to be actively involved in host-cell invasion. However, the structural and biochemical characterization of Apicomplexan parasites has proven more difficult than previously thought because of genetic and behavioral differences of the parasites’ cytoskeletal proteins that differ from those in well studied mammalian systems.
Bacterial Attachment to Oral Epithelium
Authors: Vitkov L , Krautgartner W D , Hannig M , Fuchs K 
Published: July 2020

Abstract
The purpose of this work was to examine, by electron microscopy, the mechanism of bacterial binding to oral epithelium in patients with stomatitis using ruthenium red in combination with osmium tetroxide.
Bacteriological semi-quantitative estimation of smear from the palatal mucosa was performed in patients with stomatitis and only patients with viridans Streptococci were further included in the present investigation. Biopsies were taken from the inflamed keratinizing mucosa under regional block anesthesia in agreement with Vancouver guidelines 1978. Control samples were fixed with 1.2% glutaraldehyde (buffered at pH 6.5 with 0.1 M sodium cacodylate) for 2 h at 4° C. Postfixation was performed with 1% osmium tetroxide (buffered at pH 6.5 with 0.1 M sodium cacodylate) for 2 h at 4° C. The other samples were fixed and postfixed by the fixatives mentioned before with addition of 1.6 % ruthenium red in each case.
Localization and Visualization of Specific Gene Products in Fungal Plant Pathogens
Authors: Bourett T M , Czymmek K J , Dezwaan T M , Sweigard J A , Howard R J 
Published: July 2020

Abstract
Specific gene products of both pathogens and hosts have been implicated as decisive elements during plant pathogenesis. While expression of some of these genes is constitutive, that of others is likely ephemeral and activated only during a particular stage of the interaction. Because the relative timing of expression may be critical, transcription and translation have often been addressed by extracting mRNA and proteins from infected plant tissue. This approach, however, cannot readily detect proteins of low abundance in bulk samples nor offer much useful information on cell-cell interaction. Only a cytological analysis that employs microscopy can resolve the temporal and spatial details of gene expression. Typically, such protein localization studies have required specific antibodies, but these large probe molecules do not diffuse into living or conventionally fixed cells of either fungal pathogens or plant hosts. For TEM analysis, these permeability-imposed limitations have been reduced by thin sectioning to render accessible antibody binding sites.
High-Pressure Freezing to Study Structure and Function of the Host Parasite Interface
Authors: Mendgen K 
Published: July 2020

Abstract
The high-pressure freezing instrument exposes a sample to a pressure of 2100 bar, which lowers the freezing point and, as a result, reduces the rate of ice nucleation and ice-crystal growth. The reduced critical cooling rate allows adequate freezing of samples up to 0,3 mm in thickness without using cryoprotectants. Before pressure application, the sample is sandwiched between specimen holders. To optimize heat conductivity and to avoid damage by the high pressure impact, the free space inside the specimen holders and within the sample has to be filled with liquid. This means that plant leaves need to be infiltrated to remove gas from the intercellular space. We have used water, 3-8% methanol in water, 1-hexadecene or heptane as infiltration medium. Subsequently, samples were freeze substituted in unhydrous acetone with 2% Os04 for 24 h at -90°C. Samples were slowly warmed up to 4°C and embedded in Unicryl, or warmed up to room temperature and embedded in epoxide resin.
Use of Freeze Substitution for TEM Studies of Fungal Spores
Authors: Minis C W , Richardson E A 
Published: July 2020

Abstract
Since its initial use to fix fungal hyphae (1), plunge freezing followed by freeze substitution has become the “gold standard” for TEM studies of fungal hyphae and spores. In this presentation we discuss results we have obtained using plunge freezing and freeze substitution to fix various types of spores produced by plant pathogenic fungi. Examples include basidiospores and aeciospores of rust fungi, teliospores of rust and smut fungi and conidia of a variety of ascomycetes and deuteromycetes.
Generally speaking, plunge freezing followed by freeze substitution usually yields best results when spore diameter does not exceed 10-15 μm. However, in a number of cases we (2) have obtained good to excellent results with much larger spores. A key to good freezing appears to be direct exposure of spores to liquid propane during plunging. We have had best results by placing spores on small pieces of dialysis membrane and then plunging these membranes. In most cases the spores remain attached to membranes throughout the freezing, substitution, infiltration and embedment procedures.
Abnormal STEM Development in Maize nal/nal Mutant - A Confocal Microscopy Study
Authors: Cheng Wayne Y , Cheng Ping-chin , Walden David B 
Published: July 2020

Abstract
There are number of dwarf mutants in maize such as d8, dl and nal. The nana plant 1 (nal/nal) is characterized as short erect dwarf; the phenotype does not respond to treatment of giberellins. The recessive nal allele is located on the long arm of chromosome 3 (3L-113). In this study, we report the abnormal development of the stem vasculature and the lack of clearly defined nodes.
Maize (Zea mays L., var. Ohio 43 and nal mutant) plants were grown in 1999 summer nursery at the fieldstation of University of Western Ontario, London Ontario, Canada. Plants at approximately 2 months old were fixed in 1:3 acetic acid/ EtOH. Multiple changes of fixative were made for a period of a month to remove as much pigmentation as possible. The specimen was then washed thoroughly, stained in diluted Schiffs reagent (10%), washed in 0.1M metabisulphate solution (with 1 ml of 1 N HC1 per liter), dehydrated in EtOH and cleared in methyl salicylate.