bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease
Authors: Vacca-Galloway L. , Zhang Y.Q. , Bose P. , Zhang S.H. 
Published: June 2020

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.
EM and microspectrophotometric analysis of biological delignification of plants
Authors: Akin D. E. , Rigsby L. L. , Morrison W. H. , Sethuraman A. , Eriksson K.-E. L. 
Published: June 2020

Aromatic constituents such as lignin bind to carbohydrates within plant cell walls and thus render the plant carbohydrates less utilizable as food and energy. Chemical methods used to upgrade the quality of plant biomass are costly, expensive, and unsafe. White rot fungi, which are the only known microorganisms that, to any extent, can remove lignin from plant cell walls, offer a biological solution to upgrading plant quality. Microscopic analyses provide information on the site of delignification that is strategically important in improving use of plant biomass.Stems of grasses and a legume were treated with the white rot fungi Ceriporiopsis subvermispora and Cyathus stercoreus for 6 weeks. Treated residues were analyzed for structural modifications using scanning and transmission electron microscopy and for aromatic constituents using ultraviolet (UV) absorption microspectrophotometry and gas chromatography. These modifications were related to improved utilization of cell walls by rumen microorganisms.UV absorption microspectrophotometry, in conjunction with gas-chromatography of alkali-treated plants, indicated that ester-linked ferulic and ρ-coumaric acids were particularly susceptible to removal by both fungal species.
A SEM study of atrazine effects on red shiner (Cyprinella lutrensis)
Authors: Messaad Ibrahim A. , Peters Edward J. , Rogers Douglas G. , Lee Kit W. 
Published: June 2020

Atrazine is widely used in agriculture to control weeds. However, little is known about the effects of long-term exposure in fish. Normal fish gill morphology and ultrastructure have been studied using scanning electron microscopy (SEM). Pollutants including pesticides can cause lesions in gills, which ultimately affect osmoregulation and oxygen consumption.Specimens of red shiner (Cyprinella lutrensis) were collected from the Platte River, Nebraska, by seining and treated with sodium chloride and malachite green to reduce infections. Fish were randomly distributed to aerated glass aquaria. Biological sponge filters were used to keep aquaria clean during the 14 day bioassay. Fish were maintained at a 22°C on a 12:12 photoperiod, and fed a commercial fish food once daily. Atrazine concentrations of 0, 10, 100, and 1000 μg L-1 were used. For scanning electron microscopy, fish were fixed in 3% glutaraldehyde in 0.1 M phosphate buffer. Then, gills were removed and post-fixed in 1% OsO4.
ultrastructural process of intestinal wound healing
Authors: Vaughn Rick L. , Saxena Shailendra K. , Sharp John G. 
Published: June 2020

We have developed an intestinal wound model that includes surgical construction of an ileo-cecal patch to study the complex process of intestinal wound healing. This allows approximation of ileal mucosa to the cecal serosa and facilitates regeneration of ileal mucosa onto the serosal surface of the cecum. The regeneration of ileal mucosa can then be evaluated at different times. The wound model also allows us to determine the rate of intestinal regeneration for a known size of intestinal wound and can be compared in different situations (e.g. with and without EGF and Peyer’s patches).At the light microscopic level it appeared that epithelial cells involved in regeneration of ileal mucosa originated from the enlarged crypts adjacent to the intestinal wound and migrated in an orderly fashion onto the serosal surface of the cecum. The migrating epithelial cells later formed crypts and villi by the process of invagination and evagination respectively. There were also signs of proliferation of smooth muscles underneath the migratory epithelial cells.
Baculovirus ACMNPV as well as RNA- and protein-synthesis inhibitors induce apoptosis in a continuous midgut cell line, FPMI-CF-203, of Choristonuera fumiferana (Lepitoptera: tortricidae)
Authors: Brownwright A.J. , Palli S.R. , Caputo G.F. , Sohi S.S. 
Published: June 2020

Apoptosis is an active cellular self-destruction regulated by expression or repression of certain genes. Apoptosis can be caused by a variety of both external and internal stimuli. Whether these different stimuli that can cause apoptosis converge into a final pathway that leads to self-destruction is not known. This paper compares apoptosis caused by a baculovirus, an RNA-synthesis inhibitor and a protein-synthesis inhibitor.Inoculation of IPLB-SF-21 (SF-21) and FPMI-CF-203 (CF-203, Fig. 1, ) cells with Autographa californica multicapsid nuclear polyhedrosis virus (AcMNPV) and Choristoneura fumiferana multicapsid nuclear polyhedrosis virus (CfMNPV), respectively, results in successful infection as visualized by formation of occlusion bodies (OBs). However, inoculation of CF-203 cells with AcMNPV, or SF-21 cells with CFMNPV, is unsuccessful and no OBs are seen. Inoculation of CF-203 cells with AcMNPV results in premature lysis of cells beginning at 12 hr post-inoculation (pi) and most of the cells are lysed by 48 hr pi.
Ultrastructure of human herpesvirus 7
Authors: Goldsmith C. S. , Burns D. , Pellett P. E. , Zaki S. R. , Black J. B. 
Published: June 2020

Human herpesvirus 7 (HHV-7) was originally isolated in 1989 from the peripheral blood lymphocytes of a healthy individual. Most children between 2 and 5 years of age develop antibodies against HHV-7, and the virus has recently been implicated as the causative agent in secondary episodes of the childhood disease roseola infantum. Approximately 90% of the general population is seropositive, and virus can be isolated from the saliva of up to 75% of healthy adults. This study describes the ultrastructural growth properties of an HHV-7 isolate obtained from a saliva specimen.Cord blood lymphocytes (CBLs) were inoculated with cell-free virus and harvested at days 1, 3, 4, 5, and 7. The growth curve for HHV-7 was determined by examining the ultrastructure of the cells for signs of viral production and by monitoring the cells with an anti-complement immunofluorescence assay for the presence of viral proteins.The nuclei of HHV-7-infected CBLs typically had viral nucleocapsids scattered throughout, although the capsids would occasionally converge into organized structures (Fig. 1).
Glucose metabolism in cancer cells: immunogold localization of hexokinase to the outer mitochondrial membrane
Authors: Arora Krishan K. , Decker Glenn L. , Pedersen Peter L. 
Published: June 2020

Hexokinase (ATP: D-hexose 6-phophotransferase EC 2.7.1.1) is the first enzyme of the glycolytic pathway which commits glucose to catabolism by catalyzing the phosphorylation of glucose with ATP. Previous studies have shown diat hexokinase activity is markedly elevated in rapidly growing tumor cells exhibiting high glucose catabolic rates. A large fraction (50-80%) of this enzyme activity is bound to the mitochondrial fraction (1,2) where it has preferred access to ATP (3). In contrast,the hexokinase activity of normal tissues is quite low, with one exception being brain which is a glucose-utilizing tissue (4). Biochemical evidence involving rigorous subfractionation studies have revealed striking differences between the subcellular distribution of hexokinase in normal and tumor cells [See review by Aroraet al(4)].In the present report, we have utilized immunogold labeling techniques to evaluate die subcellular localization of hexokinase in highly glycolytic AS-30D hepatoma cells and in the tissue of its origin, i.e., rat liver.
Microvasculature and structure of hemal lymph nodes in the wall of the rabbit bladder: a vascular corrosion casting and EM study
Authors: Hossler F.E. , McKamey M.I. , Monson F.C. 
Published: June 2020

A comprehensive study of the microvasculature of the normal rabbit bladder, revealed unusual "capillary glomeruli" along the lateral walls. Here they are characterized as hemal lymph nodes using light microscopy, SEM, TEM, ink injection, and vascular casting.Bladders were perfused via a cannula placed in the abdominal aorta with either 2% glutaraldehyde in 0.1M cacodylate buffer (pH 7.4) for fixation, 10% India ink in 0.9% saline and 0.1M phosphate (pH 7.4) for vessel tracing, or resin (Mercoximethylmethacrylate: catalyst, 4:1:0.3; Ladd Research Industries) for vascular corrosion casting. Infusion pressure was 100mm Hg. Fixed tissue was sectioned from epon-araldyte resin, and stained with toluidine blue for light microscopy, and lead and uranium for TEM. Ink injected tissue was photographed directly from saline-filled bladders illuminated from below. Resin-filled tissue was macerated in 5% KOH and distilled water. Casts were critical point dried, sputter coated with goldpalladium, and examined by routine SEM at 10 KV.
Cluster labels - Au11 and W11
Authors: Hainfeld James F. 
Published: June 2020

The undecagold (Au11) complex has previously been described and was used to label the biotin binding site an ovidin to ∼10 Å resolution. This is the first time this high a resolution has been obtained with a label on single isolated molecules. The gold complex was also used to mark carbohydrate moieties on a glycoprotein.A W11 complex linked to a long hydrophobic tail was used to label lipid bilayers. An improved Au11 complex which is monofunctional has now been synthesized by two independent routes, one by Frey and one by Safer.
Structural and functional renal alterations in five-sixth nephrectomized rats on unrestricted diet
Authors: Stachura I. , Pardo M. , Costello J. , Landwehr D.M. 
Published: June 2020

Under experimental conditions severe reduction of renal mass results in the hyperfiltration of the remaining nephrons leading to a progressive renal insufficiency. Similar changes are observed in patients with various renal disorders associated with a loss of the functioning nephrons. The progression of renal damage is accelerated by high protein and phosphate intake, and may be modified by the dietary restrictions.We studied 50 five-sixth nephrectarrized male Wistar rats on a standard diet (Rodent Laboratory Chow 5001 Ralston Purina Co., Richmond, Indiana; containing 23.4% protein) over a 20 week period.
Shock consolidation of Ni-Ti alloy powder
Authors: Thadhani Naresh N. , Vreeland Thad , Ahrens Thomas J. 
Published: June 2020

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.
Precursors to crystallization in amorphous CdGeAs2
Authors: Speyer R.F. , Kriven W.M. , Risbud S.H. 
Published: June 2020

A myriad of crystalline microstructures may be obtained by minute variations in thermal treatment during the devitrification of CdGeAs2 from the glass. Differential Scanning Calorimetry (DSC) studies show that the single crystallization exotherm observed under moderate heating conditions, splits into two superimposed exotherms (a moderately energetic one followed by a substantially energetic one) at very slow heating rates, as shown in Figure 1.It is believed that the first DSC exotherm represents the nucleation and partial growth of a non-stoichiometric. crystalline precursor phase. X-ray diffraction studies of samples sequentially quenched along the DSC exotherm indicated, to reasonable confidence, that the precursor phase was pure germanium, and with absolute confidence that the larger exotherm represents the formation of CdGeAs2 adopting the chalcopyrite structure. The TEM. STEM, and EDS studies described herein substantiate our elucidation of the precursor phase.
The characterization of rapidly solidified Al-8Fe-2Mo powder
Authors: Plummer H.K. , Donlon W.T. , Allison J.E. , Shinozaki S. 
Published: June 2020

A centrifugally atomized rapidly solidified Al-8Fe-2Mo powder was characterized by Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Analytical Electron Microscopy (AEM). The powder sample was studied in an as-solidified state and after annealing in 1 at. argon for 6 hr at 400°C. Further studies have characterized the consolidated bars produced by compaction and extrusion of these powders.The 30 to 150 μm powders are spherical as seen in the SEM (Fig.1) with small (5 to 15 μm) satellite powders sometimes attached in external (A,B Fig.1) and internal (A Fig.2C) locations. A comparison of powders (epoxy mounted and polished) by both the LM (Fig. 2A) and the SEM (Figs. 2B and 2C) reveals a two component microstructure with occasional voids.
The effect of metallurgical factors on the quality of fine multifilamentary NbTi superconducting wires
Authors: Sabatini R. L. , Suenaga M. , Garber M. 
Published: June 2020

Metallurgical factors during the fabrication process have a large influence on the quality of composite NbTi multifilamentary superconducting wire. The observed critical current density, Jc, is sensitive to microstructure on the scale of the fluxoid-defect interaction, and also to macroscopic variations in filament diameter.Earlier work at the University of Wisconsin, Lawrence Berkeley Laboratory, Wah Chang, and Intermagnetics General Corp. was concentrated on improving the intrinsic Jc for wires with a relatively large filament diameter (~20 μm). By improving homogeneity of the NbTi alloy and by optimizing the drawing-anneal treatment schedule, wires with Jc ∼3000 A/mm2 were produced.
Modern TEM systems architecture
Authors: Gross U. , Hagemann P. 
Published: June 2020

By addition of analytical equipment, scanning transmission accessories and data processing equipment the basic transmission electron microscope (TEM) has evolved into a comprehensive information gathering system. This extension has led to increased complexity of the instrument as compared with the straightforward imaging microscope, since in general new information capacity has required the addition of new control hardware. The increased operational complexity is reflected in a proliferation of knobs and buttons.In the conventional electron microscope design the operating panel of the instrument has distinct control elements to alter optical conditions of the microscope column in different modes. As a consequence a multiplicity of control functions has been inevitable. Examples of this are the three pairs of focus and magnification controls needed for TEM imaging, diffraction patterns, and STEM images.
Observation of liquid transport in the ESEM
Authors: Danilatos G.D. , Brancik J.V. 
Published: June 2020

The environmental SEM (ESEM) allows the observation of liquid and liquid/solid systems in a controlled gaseous environment. In order to study the wetting properties of a wool fiber, or to understand various stages of wool scouring, a system has been devised which allows the transfer of microdroplets onto the specimen surface. A description of the microinjector device together with dynamic observations of liquid transport recorded on video cassette are reported here.Fig. 1 shows a descriptive diagram of the principle employed to transfer liquids from ambient pressure (about 1000 mbar) into the specimen chamber at hypobaric pressure (about 25 mbar). A small cavity (L) is open to the outside space via two tubes M (with 1 mm inside diameter) so that this cavity can be filled or emptied freely and quickly with a given liquid from the outside.
Transmission electron microscopy of semiconductor devices
Authors: Brown J. M. 
Published: June 2020

The search for further miniaturization in the semiconductor industry has resulted in the reduction in the dimensions of devices to a size which can no longer be effectively seen by the conventional methods of light microscopy. The use of both transmission and scanning electron microscopy in the field of silicon device characterization has now become an essential ingredient of the design and manufacture of new technologies. It is often the only way in which a device designer can know for certain whether the manufacturing process is producing the required structure. Cross-sectional TEM has therefore become an integral part of both quality control and development.One of the most important areas which resulted in the increased importance of TEM in the semiconductor device field was the development of sample preparation techniques which enable cross-sections through layers of widely differing compositions that are found in the devices structures.
Mono-Atomic Tips and Scanning Tunneling Microscopy
Authors: Fink H.-W. 
Published: June 2020

The power of the Scanning Tunneling Microscope (STM) to resolve the detailed structure of solid surfaces is based on the strong distance dependence of the tunnel current, while the tip is scanned over the surface to be investigated.In the first part of the paper, the basic principles of operation of the STM are to be reviewed, and examples of the information that can be obtained today are presented. From this, it will be evident that knowledge of the atomic arrangement of the tip is important in order to separate tunnel-current changes related to the tip from those owing to the structure of interest, namely, the sample surface.
Limits of the STEM
Authors: Crewe Albert V. 
Published: June 2020

I suppose that there will be cynics in the audience who believe that the very title of this talk is a non-sequitor - that STEMs are inherently and severely limited. They are, of course, wrong. Nevertheless, it is apparent that the belief is widespread since there are so few STEMs in everyday use. For this reason it is important to address both issues, the physical limitations of the STEM and the perceptual limitations of the average microscopist.It is difficult to know where to begin because there is so much to say, but there is one word of caution which must be said at the beginning. Only about thirty or so STEMs have been built and I doubt whether anyone who has built one would claim that it was the best that could be done. Compared with the experience and engineering manpower which has gone into the CTEM, the effort on the STEM has been miniscule. We must therefore speak more about what could be done or what could have been done than about actual accomplishments.
Freeze-fracture cytochemistry: A goal set by Russell Steere in 1957
Authors: Severs Nicholas J 
Published: June 2020

In his pioneering demonstration of the potential of freeze-etching in biological systems, Russell Steere assessed the future promise and limitations of the technique with remarkable foresight. Item 2 in his list of inherent difficulties as they then stood stated “The chemical nature of the objects seen in the replica cannot be determined”. This defined a major goal for practitioners of freeze-fracture which, for more than a decade, seemed unattainable. It was not until the introduction of the label-fracture-etch technique in the early 1970s that the mould was broken, and not until the following decade that the full scope of modern freeze-fracture cytochemistry took shape. The culmination of these developments in the 1990s now equips the researcher with a set of effective techniques for routine application in cell and membrane biology.Freeze-fracture cytochemical techniques are all designed to provide information on the chemical nature of structural components revealed by freeze-fracture, but differ inhowthis is achieved, in preciselywhattype of information is obtained, and inwhichtypes of specimen can be studied.
Immunolocalization of phospholipids using freeze-fracture cytochemistry
Authors: Kan Frederick W.K. , Rauch Joyce 
Published: June 2020

Phospholipids are found ubiquitously in all mammalian cell membranes. The fracture-label technique offers the opportunity to localize phospholipids in tissues and cells. This technique has recently been used in combination with colloidal-gold-conjugated phospholipase A2 to demonstrate the presence of phospholipids in epithelial tight junctional strands. In the present study, we show the localization of specific phospholipids in the plasma and intracellular membranes in the rat exocrine pancreatic cells using murine monoclonal anti-cardiolipin (CL) antibodies that are reactive with phosphatidylethanolamine (PE) and have lupus anticoagulant activity. These antibodies were produced from BALB/c mice immunized with either ADP-activated murine platelets or CL mixed with apolipoprotein H.Pancreatic tissue was excised from adult male Sprague-Dawley rats under light ether anesthesia and fixed by immersion with 1% glutaraldehde in 0.1 M cacodylate buffer. The tissue was trimmed into 1-mm cubes which were then embedded in 30% bovine serum albumin in 0.01 M PBS, and cross-linked with a final concentration of 1% glutaraldehyde to form a hardened gel.
Confocal microscopy of the cytoskeleton in living plant cells following microinjection of fluorescent probes
Authors: Cleary Ann 
Published: June 2020

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study ofTradescantiastamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells ofTradescantialeaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.