bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphometrical Ultrastructural Studies of the Rat's Hepatocytes Under Cooling
Authors: Kaprelyants AS , Kaprelyants AA , Reylan AN , Migunova RK 
Published: July 2020

Abstract
The aim of given investigation is to study the effect of cooling upon rat hepatocyte structure using transmission electron microscopic and computer morphometric methods. Ultrastructural and morphometrical characteristics of hepatocytes under liver cooling for various levels under in vivo and in vitro conditions were investigated. Vistar rats of 180-250 g were used in the experiment. Liver cooling (in vivo) was performed by means of original cryoapplicator with different probe temperature (1,2). Liver tissue for transmission electron microscopy was fixed in glutaraldehyde fixator on cocadylate buffer and OsO4. Dehydration was completed on acetone (3). Tissue embedding was done into the mixture of Epon/Araldite epoxy rasin. Ultrathin slices were contrasted by the method of Reinolds. Cell viewing and imaging were accomplished by electron microscope at accelerating power of 75kV.
Morphometrical and stereometrical analysis was performed using the “Morpho-Tools” original computer system (c) 1994-1996 A.S. Kaprelyants, A.A. Kaprelyants, A.N. Reylan.
Avian Extended Junctional SR: 3-D Geometry Rendered in Stereo
Authors: Sommer JR , High T , Ingram P , Kopf D , Nassar R , Taylor I 
Published: July 2020

Abstract
Extended junctional sarcoplasmic reticulum (EJSR) is an invariant differentiation of the sarcoplasmic reticulum (SR) in bird cardiac myocytes (CM) and central to excitation-contraction coupling (ECC). EJSR occurs as both continuous and discontinuous extensions of junctional sarcoplasmic reticulum (JSR), and surrounds and pervades the Z/I band as the “ EJSR Z-rete” whose geometry has mechanistic implications for the function of “couplings” in ECC, in general. “Peripheral coupling(s)” (PC) in birds, and the additional “interior coupling(s)” (IC) at transverse tubules (TT) in mammals, are formed by tight apposition to plasmalemma of JSR, a specialized calcium (Ca) store of the SR. Free SR (FSR; i.e. free of JSR/EJSR specializations) is the rest of the smooth, tubular SR network, which connects intercalated patches of EJSR forming the EJSR Z-retes and, elsewhere, displays both longitudinal and transverse geometries in surrounding the contractile material for the purpose of sequestering Ca after each muscle contraction. Except for EJSR having no plasmalemmal contact, morphologically, EJSR and JSR are homologues:1 both have similar sizes; are studded (approx. 32 nm center-to-center) with junctional processes (JP; ryanodine receptor (RyR)/-Ca-release channels);
EM Study of Gastric Tumor Microvasculature
Authors: Tonino P , Finol HJ , Sosa L , Hidalgo C , Salomón MC , Negri C , Godayol F 
Published: July 2020

Abstract
It has been considered that the behavior of tumors is consistent with the concept that tumor growth is angiogenesis dependent. However, additionally to the newly formed vessels other patterns of tumor capillaries have been described. Information concerning the ultrastructure of tumor blood vessels has been obtained mostly from experimental models. With regard to human tumors, since no systematic ultrastructural studies are available on the gastric tumor microvasculature, the aim of the present work was to characterize the vascular architecture of this type of tumor.
Surgically resected specimens were obtained in tumors from five patients (three males and two females) between 45 to 66 years of age (mean, 56.2 years), with a histopathological diagnosis of moderately differentiated gastric adenocarcinoma. Immediately after resection, tissue samples taken from areas of tumor center were processed by routine transmission electron microscopy techniques and observed in a Hitachi H-500 EM.
The microvasculature within gastric adenocarcinomas was characterized by newly formed capillaries with proliferative endothelial cytoplasm (Fig. 1).
Vacuolation in Renal Tubular Epithelium of Mice: an Incidental Lesion
Authors: Dovey-Hartman BJ , Johnson RC , Leach MW , Frank DW , Sinha D E , Mirro EJ , Little JM , Halliwell WH 
Published: July 2020

Abstract
Prominent cytoplasmic vacuoles in renal tubular epithelial cells of the outer medulla were observed in several kidneys from test article-dosed mice during routine light microscopic (LM) examination. Because the vacuolar change was seen infrequently by LM examination, and was not found in any control mice from that study, it was not clear whether the vacuolation represented a drug-induced change. To address this question, kidney sections from multiple unrelated mouse studies (214 control mice and 541 test article-dosed mice representing six different compounds) were examined by LM for similar vacuolar changes. Vacuolation was seen by LM in 2.3% of the control and 2.8% of the test article-dosed mice. Transmission electron microscopy (TEM) was performed on kidneys with prominent vacuoles seen by LM in 5 control mice and 2 test article-dosed mice to further characterize the vacuoles. Additionally, kidneys from 4 randomly selected control mice lacking vacuolation by LM were examined by TEM. Samples from the outer medulla of kidney that had been fixed by immersion in 10% formalin were post-fixed in 2.5% glutaraldehyde and 2% osmium tetroxide and processed routinely for TEM.
Tissue Response to Bone Substitute Materials
Authors: Krizan K E , Lew D , Farrell B B , Laffoon J E , Keller J C 
Published: July 2020

Abstract
The purpose of this study was to compare the biological response to two bone substitute materials, hydroxyapatite cement (HAC) and demineralized bone (DMB), when placed in canine cranial bone. The implants were surgically positioned in 15 mm diameter defects created in the parietal plate, harvested en bloc at 3 months (m) and 6m postop, and fixed in 70% ethyl alcohol to preserve the xylenol orange bone label. Half of each implant site was processed into paraffin and the other half into Spurr plastic resin. In order to evaluate the osseoinductive properties of DMB, implants were also surgically placed in the rectus femorous muscle, harvested en bloc at 3m post op, fixed in 0.1 M Na phosphate buffer, pH 7.2, decalcified in 5% EDTA, pH 7.2, and embedded in plastic. All implants were evaluated with light microscopy (LM), radiography, energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). Tissue for LM was routinely decalcified with SFFA, embedded in paraffin, sectioned, stained with hematoxylin/eosin, and viewed with a Zeiss transmitted-light photomicroscope [Figs. 1, 2, 5].
Highlights of Selected Microscopy Research Resource Activities at San Diego
Authors: Ellisman Mark H , Young Stephen J , Fan G Y , Perkins Guy , Lamont Steve , Martone Maryann E 
Published: July 2020

Abstract
The intermediate high-voltage electron microscope (IVEM) located at the National Center for Microscopy and Imaging Research at San Diego (NCMIR) can image relatively thick specimens that contain substantial three-dimensional (3-D) structure. Electron tomography is an important tool used at NCMIR for deriving 3-D cellular and subcellular structure from IVEM images. Reconstruction algorithms commonly used in electron tomography include weighted back projection, and iterative algebraic reconstruction techniques such as ART and SIRT. Improvements in reconstruction quality are possible using the iterative algorithms. Because these algorithms are computationally intensive, we have ported them to massively parallel computers at the San Diego Supercomputer Center, reducing the computation time over that required with workstation level machines.
The quality of tomographic data for the 3-D reconstruction of biological structures is also being enhanced by NCMIR projects to improve the microscope. We have designed and constructed special electron optics and microscope control systems for the JEOL 4000EX.
High-Resolution Analytical Microscopy in the Center for Materials Science and Engineering at MIT
Authors: Garratt-Reed Anthony J 
Published: July 2020

Abstract
The Center for Materials Science and Engineering at MIT, a Materials Research Science and Engineering Center sponsored by the National Science Foundation, maintains and supports, amongst others, an Electron Microscopy Shared Experimental Facility. The purpose of this paper is to highlight selected recent research results for high-resolution investigations performed in that facility.
The facility owns the first VG HB603 intermediate-voltage FEG-STEM, which operates at 250KeV and is equipped with a high-solid-angle x-ray detector and a Gatan Digi-Peels. It was intended to be, and has been, used for high sensitivity, high spatial resolution microanalysis. It is well-known that the “resolution” of an x-ray analysis is intimately (and inversely) related to its sensitivity; one extreme situation occurs when analyzing, for example, a diffusion profile, when the need is to determine the composition to the highest precision. An example of such an analysis is given in fig. 1. In this case, the sample is a 1.4Cr-0.8C pearlitic steel, and the chromium analysis is carried out across a cementite plate. During the growth of the pearlite, the chromium, which is not thermodynamically required to redistribute, nevertheless diffuses along the growth interface towards the cementite, resulting in a comparatively wide depletion profile in the ferrite, and a very narrow enrichment in the cementite.
Integrated Characterization at a Canadian National Facility
Authors: McMahon G , Wronski Z , Malis T 
Published: July 2020

Abstract
The pressure of shrinking budgets and downsizing has made it increasingly difficult to meet requests for comprehensive microstructural characterization. In many laboratories, especially those in industry, the expense of maintaining and staffing electron, X-ray and ion beam facilities has resulted in fewer analytical capabilities. At the same time, modern materials and products continue to diversify and increase in complexity, requiring increasingly sophisticated techniques. This growing paradox has increased the need for multiclient, shared-access ‘clusters’ of microanalytical instruments.
The above federal laboratory is mandated to serve both the Canadian public (in a broad sense) and Canadian industry (in the specific sense of collaborative and contract research projects). As a result, the Characterization Group has evolved into an integrated lab competency which compliments other competencies in materials processing (full-scale foundry, industrial rolling facility, Gleeble processing simulator) and mechanical behavior (fracture mechanics, stress and deformation modeling). Building on established expertise in metallography, microprobe, X-ray and TEM, the group has doubled in size (to 20 professionals and 10 major capabilities) and now includes SIMS and surface analysis (Table 1).
Capturing Developmental Events of the C. Elegans Embryo by High Pressure Freezing After Monitoring by a Multi-Photon Imaging System.
Authors: Lavin CA , Mohler W A , Keating H H , White JG 
Published: July 2020

Abstract
High pressure freezing enables the rapid arrest of developmental events without prefixation. Standard chemical fixation is a time dependent event and may cause artifacts in sensitive cytoskeletal components. We are studying two developmental events in embryonic Caenorhabditis elegans: that involve changes in the cytoskeleton: spindle alignment and membrane fusion. The mitotic spindle undergoes rapid rotational alignment prior to certain differentiative divisions. We are trying to capture these events by anticipation their timing and rapid freezing. Precursor hypodermal cells of embryonic C. elegans undergo a transition from individual cells to a syncytium at the onset of morphogenesis. In an effort to visualize the fusion events, embryos were stained with the vital probe FM4-64 to highlight cell membranes. Development was monitored by fluorescent microscopy using multiple-photon excitation imaging to minimize photobleaching while providing clear images of deep sections. Small cellulose capillary tubes, as described by Hohenberg for isolation and high pressure freezing of individual cells, were not of sufficient optical quality for monitoring by a laser-scanning microscope.
The National Nanofabrication Users Network (NNUN): Potential Applicability for Bio/Biomedical Science and Technology
Authors: Isaacson M S 
Published: July 2020

Abstract
For several decades the US scientific community has recognized the value of pooling specialized skills and equipment in centralized user facilities. Significant efficiencies are realized within the user community by avoiding unnecessary duplication and by moving projects more quickly to completion. The user facility concept served the nanofabrication community well for over two decades at the National Nanofabrication Facility (NNF) at Cornell. In 1994, the National Science Foundation expanded the concept by integrating NNF-Cornell (Now CNF) with several other nanofabrication programs throughout the country to form the National Nanofabrication Users Network (NNUN). Within this framework of a “users” network, scientists and engineers have access to state of the art equipment and expertise.
NNUN consists of two “full service” hub facilities at Cornell (the Cornell Nanofabrication Facility) and Stanford (the Stanford Nanofabrication Facility), in association with specialized facilities at Howard, Penn State and UC-Santa Barbara. The network is managed by the 5 site directors, who are responsible to NSF program management and to a Network Advisory Board.
High Resolution Magnetic Resonance Imaging of Resected Plaque
Authors: Saloner D 
Published: July 2020

Abstract
Atherosclerotic plaque at the carotid bifurcation is strongly correlated with the incidence of clinically significant events, such as transient ischemie attacks or stroke. Large multi-center trials have demonstrated that surgical removal of the atheroma is more effective in reducing these clinical events than is medical treatment alone. Patients are selected for surgery from an assessment of the severity of disease at the carotid bifurcation. The measure of disease severity is conventionally taken to be the degree of narrowing of the diseased vessel compared to a normal segment of vessel. However, using this criterion alone, many patients receive endarterectomy surgery who would probably not have progressed to other neurological events, while others are excluded who do progress to neurological events. For this reason, there is substantial interest in methods that could evaluate the composition of the atherosclerotic plaque in vivo, with the hope that this information would improve the predictive power of pre-surgical imaging of the diseased vessel.
Histologic Consequences of Endoluminal Coronary Artery Hydrogel Polymer Paving
Authors: Marijianowski MMH , Cipolla GD , Forestner DM , Campbell PK , Weselcouch EO , Slepian MJ , Apkarian RP , Robinson KA 
Published: July 2020

Abstract
Coronary artery balloon catheter angioplasty for the treatment of obstructive atherosclerosis has an unacceptably high restenosis rate of about 40% within 6 months. Local delivery of pharmaceuticals and nucleotide-based compounds is under investigation as one means to decrease recurrence. Labeled molecules, when delivered to arterial angioplasty sites in aqueous solution using porous balloon catheters, are quickly lost from the tissue. Alternative strategies include drug encapsulation in microparticles, and implantation of drug-containing polymers. We tested the feasibility of a catheter-based system to deposit a 70-μm thick layer of polyethylene glycol-lactate based hydrogel (polymerized by cross-linked end-terminal acrylate groups) onto the luminal surface of coronary arteries in pigs after balloon angioplasty, and examined the histologic consequences at one hour and seven days using light, scanning electron, and transmission electron microscopy.
At one hour the gel layer was readily visualized by all three microscopic techniques and appeared well adhered to and in intimate contact with the blood vessel surface (Figs. 1-2).
Quantitating Aortic Atherosclerosis in Rabbits and Mice
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Sanan David A , Newland Dale L 
Published: July 2020

Abstract
Build-up of visible atherosclerotic plaque in the arteries is readily quantifiable. The mouse and the rabbit provide useful models for understanding the pathogenesis of atherosclerosis by investigating the effects of genetic and dietary perturbations.
Although the wild type mouse does not develop atherosclerosis, atherosclerosis susceptibility genes have been identified in some laboratory mouse strains which do. Furthermore, transgenic technology and gene targeting have produced genetically modified mice that express various apolipoproteins, enzymes and cofactors involved in human lipoprotein metabolism. Gene “knockout” technology allows transgene expression without interference from homologous genes. One notable “knockout” mouse, deficient in apolipoprotein E, develops spontaneous atherosclerosis on a normal chow diet. Transgenic modulations of the atherosclerotic responses of these highly susceptible mice are more pronounced and easily measured. Small, cheap and fast breeding, mice are convenient animal models. But to make mice susceptible to atherosclerosis, their genetic background has to be so drastically altered that the resulting lipoprotein metabolism may not model the human metabolism accurately enough.
A Cytochemical Study of NADH Oxidase and H2O2 in Developing Atheromas
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Ann Ellis E , Bush David M , Wargovich Thomas J , Grant Maria B 
Published: July 2020

Abstract
Recent data suggests that reactive oxygen species (ROS) play a role in the progression of atherosclerosis. Superoxide (O2 ˙−) and its free radical metabolites can participate in the oxidation of LDLs, activation of proto-oncogenes and promotion of cellular growth. Endothelial and vascular smooth muscle cells are capable of producing O2 ˙− and other ROS. A major source of O2 ˙- and other reactive ROS in vascular tissues is a membrane associated NADH oxidase. This paper presents a study of NADH oxidase by cytochemical localization in developing atheromas in a rabbit model of diet-induced atherosclerosis.
NADH oxidase generates O2 ˙− which dismutates to hydrogen peroxide (H2O2). Cerium perhydroxide, an electron dense precipitate of cerium and H2O2, is the reaction product of NADH oxidase. Cytochemical localization of NADH oxidase was done by the cerium method in developing atheromas in abdominal aorta and iliac arteries of New Zealand rabbits made atherosclerotic by feeding a diet of 0.2% cholesterol/5% peanut oil over four months.
Fluorescence Intravital Microscopy of the Coronary Microvasculature
Authors: DeFily David V 
Published: July 2020

Abstract
Much of our knowledge of coronary blood flow regulation is based on global blood flow measurements or from studies of large epicardial coronary arteries. Those studies which have examined the coronary microcirculation, have often considered it as a single homogeneous vascular bed. However, regulation of coronary microvascular resistance is not distributed uniformly, but varies across different segments of the vasculature. Under normal conditions, a major portion of coronary vascular resistance is controlled by the coronary arterioles.
Studies of these vessels in vivo are difficult, due to problems associated with cardiac and ventilatory motion. To eliminate these problems, we have utilized a technique of fluorescent stroboscopic epi-illumination. Dogs (4-12 kg) were anesthetized with sodium pentobarbital, intubated, and ventilated with room air. A 24 gauge catheter was placed in the proximal left circumflex coronary artery for measurements of coronary artery pressure and administration of drugs. Following these procedures, the animal was ventilated on a high frequency jet ventilator synchronized to the cardiac cycle.
Use of Intra Vital Microscopy to Analyze Leukocyte Rolling and Adhesion In Vivo
Authors: Hickey Michael J , Kubes Paul 
Published: July 2020

Abstract
Inflammation is a vital process by which the body is able to fight infection and heal wounded tissue. However inappropriate control of inflammation is responsible for a wide range of pathologies (e.g. rheumatoid arthritis, inflammatory bowel disease). One of the hallmark features of inflammation, and one of the key pathogenic mechanisms in inflammatory disorders is leukocyte recruitment. Therefore understanding the molecular mechanisms by which leukocytes travel from the bloodstream to the extravascular tissue is of great importance.
Evidence suggests that there is a cascade of complex interactions between leukocytes and endothelium that to be fully understood must be studied on-line rather than using endpoint readouts such as tissue levels of leukocyte enzymes (myeloperoxidase) or histological techniques. A number of laboratories, including our own, have used a technique known as intravital microscopy to directly visualize leukocyte trafficking in individual vessels in a range of tissues, in an attempt to gain a better understanding of the mechanisms of leukocyte recruitment. Intravital microscopy entails microscopic examination of living tissues.
The Importance of Gamma Correction in the Acquisition, Display and Hardcoy of Digital Images
Authors: Mackenzie John M 
Published: July 2020

Abstract
Digital imaging is replacing conventional photography in many applications. As the quality of digital images improves, more applications for this technology will be found. This talk will examine the importance of gamma correction in digital imaging.
Although many researchers believe that digital imaging will soon replace photography, it is probably more correct to think of digital imaging as an enhancement to photography. The most critical problem with translating our knowledge of photography to digital imaging is that photography operates exclusively via logarithmic functions. The exposure versus density curves common to photography have an x axis that is logarithmic. The development curves for film and paper are also logarithmic. The slope of the log-linear portion of this curve is designated gamma. All operations normally performed in the darkroom whether processing film or prints manipulate the gamma functions to achieve the best recorded image. The first rule that should be obvious is that every image has a different optimal gamma and every different image medium (whether graded photographic paper or the density of print on a digital image printer) will change that optimal gamma.
Focused Ion Beam Milling for Site Specific Scanning and Transmission Electron Microscopy Specimen Preparation
Authors: Giannuzzi LA , Drownt JL , Brown SR , Irwin RB , Stevie FA 
Published: July 2020

Abstract
It has been shown that a focused ion beam (FIB) instrument may be used to prepare site specific cross-sectioned specimens to within &lt; 0.1 μm for both scanning and transmission electron microscopy (SEM and TEM, respectively). FIB specimen preparation has been used almost exclusively in the microelectronics industry. Recently, FIB specimen preparation has been utilized for other materials systems and applications.
A cross-sectioned SEM specimen is produced by sputtering away a trench of material from near the region of interest. Large amounts of material are sputtered using large ion beam diameters (e.g., l00’s nm) and high beam current (e.g., l000’s pA), while the final sputtering operations are achieved using smaller beam diameters (e.g., &lt; 10 nm) and lower beam current (e.g., 10’s of pA). The SEM specimen may then be etched to reveal particular microstructural features of interest. A low magnification SEM image of a multi-layered device prepared for cross-section analysis by the FIB method is shown in FIG. 1.