bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructural Studies of Nipah Virus, A Newly Emergent Paramyxovirus, Using Thin Section, Negative Stain, Immunogold, and in Situ Hybridization Electron Microscopy
Authors: Goldsmith Cynthia S , Whistler Toni , Rollin Pierre E , Chua Kaw Bing , Bellini William , Rota Paul , Wong K T , Daszak Peter , Ksiazek Thomas G , Zaki Sherif R 
Published: July 2020

Abstract
An increase in cases of acute febrile encephalitis occurred in Western Malaysia between September 1998 and May 1999, and a similar illness was reported in Singapore in March 1999. Most cases occurred in males who had been exposed to pigs, or among abattoir workers, and at least 100 deaths were reported. The illness was characterized by fever and headache, followed by drowsiness and disorientation; patients with severe cases developed seizures and coma within 24 to 48 hours. Concurrently, there were also illnesses and deaths among pigs in the same region, although the symptoms predominantly involved the respiratory system, and only a few pigs had signs of neurologic disease. From a cerebral spinal fluid specimen from a human patient, Dr. Chua and colleagues were successful in isolating a virus that was morphologically identified as belonging to the family Paramyxoviridae, and is now known as Nipah virus.
The Plain and the Ugly Prion Infected Neuronal Tissue in an Experimental Animal Model; An Electron Microscopic Study.
Authors: Milroy A M , Bouzamondo E , Ralston III H J , Prusiner S B , DeArmond S J 
Published: July 2020

Abstract
Transmissible encephalopathy of animals (scrapie and bovine spongiform encephalopathy) and of man (Creutzfeldt-Jacob disease, new variant Creutzfeldt-Jacob disease, Kuru, Gerstmann-Straussler-Scheinker disease and familial fatal insomnia) have been well characterized as progressive neurodegenerative diseases, often associated with spongiform degeneration, neuronal loss, reactive astrocytic gliosis and variable amyloid plaques, without any sign of an immune response or inflammatory infiltrates. Prion proteins are elements that propagate variability through multiple biologically active conformers of a host encoded sialoglycoprotein (PrPc). The agent responsible for transmissible encephalopathies is composed mainly, if not exclusively, of an isoform of PrP, designated PrPSc. Extensive information of post-mortem material has been described at the light microscopic level, where the emphasis has been on spongiform tissue and amyloid plaques. Our study provides ultrastructural observations of the central nervous system, specifically of degenerating neurons and their associated changes during the course of scrapie infection in a hamster model.
A Rickettsia in the Ovary of the Twospotted Spider Mite, Tetranychus Urticae KOCH (Acarina: Tetranychedae)
Authors: Crooker Allen R 
Published: July 2020

Abstract
Rickettsias are small, gram-negative Alpha Proteobacteria that are, with one exception, obligate intracellular parasites. They are found in a wide range of arthropods. Some of these bacteria are arthropod-vectored disease agents of vertebrates. For example, rickettsias are the causative agents of human typhus and Rocky Mountain spotted fever. Others, such as Wolbachia, are important manipulators of their arthropod host's reproductive capabilities and are not currently known to be disease agents of vertebrates.
Research on Wolbachia and related rickettsias has increased dramatically in recent years. Most of the attention has been focused on insects, although there are occasional reports of rickettsiae being found in isopods and mites. Most recently, the use of molecular techniques has established that Wolbachia is widespread in spider and predatory mites. However, Wolbachia or other rickettsias have not been demonstrated ultrastructurally in the spider mites. This report documents the presence of a rickettsia in the ovary of the adult female twospotted spider mite, Tetranchus urticae Koch, an economically important pest of ornamental and crop plants.
Observation of Amyloid-Like Fibers of the Sup35 Protein from Saccharomyces Cerevisiae
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Kowal Anthony S , Scheibel Thomas , Lindquist Susan L 
Published: July 2020

Abstract
In the yeast Saccharomyces cerevisiae, [PST] acts as an epigenetic modifier of translation termination efficiency. [PSI+] can be passed through generations of yeast cells via changes in protein conformation rather than changes in DNA or RNA, and has thus been referred to as a yeast prion. The [PSI+] determinant is the Sup35 protein. Sup35 can exist in two states - soluble and insoluble. Soluble Sup35 functions in translation termination, but when insoluble, stop codons are read through, resulting in incorrect protein products.
Sup35 is composed of three distinct domains, N, M, and C. The N region is rich in glutamine and asparagine and is required for the [PST] phenotype to exist. M is a highly charged domain, and no specific function has been assigned to it. C is essential in yeast, as it is responsible for translation termination. The insoluble form of Sup35 has characteristics reminiscent of other prion proteins - in vitro it binds to the dye Congo Red and it exhibits apple green birefringence in polarized light.
Detection and Identification of Viruses in Economically Important Insects
Authors: Bailey GW , McKernan S , Price RL , Walck SD , Charest P-M , Gauvin R , Styer E L , Hamm J J 
Published: July 2020

Abstract
Economically important insects include pests of plants, animals and stored products as well as insects produced commercially (honey bees, silkworms, insects for fish bait and food for birds and zoo animals). Other insects are produced in large numbers for experimental purposes, biological control of insect pests and weeds and the production of sterile insects for population suppression. Insect viruses may affect morphology, physiology and behavior, often reducing longevity and reproductive potential. Thus insect viruses can be used as biological control agents of pest insects. Insect viruses may also interfere with the production or function of biological control agents (e.g., parasitoids and predators) and insects used for research purposes. Therefore, it is advantageous to screen commercial and research colonies and imported insects for viruses.
Electron microscopy of negatively stained specimens (NS EM) offers a relatively rapid and inexpensive means of screening populations of insects for the presence of viruses or viruslike particles and to monitor the progress of virus control programs.
Ultrastructural Analysis of Beta-Amyloid Production in Monocytes, Astrocytes, Epithelial, and Endothelial Cells Infected with Chlamydia Pneumoniae Isolated from Alzheimer Brains
Authors: Little CS , Maclntyre A , Hammond C , Venuti E , Bromke BJ , Balin BJ , Appelt DM 
Published: July 2020

Abstract
Previously, we uncovered evidence of an infectious agent, Chlamydia pneumoniae, associated with sporadic Alzheimer's disease (AD). We demonstrated that C. pneumoniae was present in 90% of brain materials examined from AD patients, compared with 5% in age-matched, non-AD patients. We further showed that microglia and astroglia in the CNS are host cells for the bacterium. RT-PCR analyses indicated that the bacterium is metabolically-active in the brain and could be cultured in a human monocyte cell line (THP-1). Importantly, we showed that the organism is concentrated in areas of AD-neuropathology also containing tau and beta-amyloid. The present study was designed to investigate the effects of C. pneumoniae infection on beta amyloid production in human monocytes (THP-1), astroglial (CCF-STTG1), epithelial (Hep 2), and endothelial (HBMEC) cell lines. We investigated the host pathogen relationship with C. pneumoniae and whether entities characteristic of AD neuropathology such as betaamyloid are associated directly with this infectious agent.
Using Microdensitometry and Image Analysis to Study Nuclear Cycle Events in a Plant Pathogenic Fungus
Authors: Snetselaar K , Lee S , Nguyen A , McCann M 
Published: July 2020

Abstract
Determining the length of the various stages of the nuclear cycle and correlating nuclear cycle events with particular aspects of cell morphology generally require the use of autoradiography. The most useful label is tritiated thymidine, because it is incorporated only into DNA. Unfortunately fungi, unlike most other organisms, do not take incorporate thymidine from medium. In the past, microspectrophotometry has been used to study fungal nuclei, but this technique measures nuclei one at a time. Recent advances in image capture and analysis software have made it possible to use the technique of photomicrodensitometry to quantify DNA in nuclei stained with fluorochromes that bind quantitatively to DNA. We are using this method to study nuclear cycle events in cells of the pathogenic fungus Ustilago maydis.
The basidiomycete fungus Ustilago maydis causes corn smut disease. This fungus is dimorphic—in addition to growing by filaments in corn plants, it can exist saprobically in a yeast-like budding stage.
Induction of Transfer Cells in XYLEM of Zinnia Elegans Treated with Cadmium
Authors: Chen C C , Chen W T , Wang S Y , Chen Y R 
Published: July 2020

Abstract
Cadmium and zinc are transition elements belonging to group II B in periodical table and they share similar chemical properties. However, their morphological and physiological effects on plants are quite difference. Cadmium not only consequences changes of plant structure at the light and electron microscopic levels, but also results in the induction of phytochelatin synthesis. In the present studies, The distribution of cadmium in different parts of plants was measured and its effects on plant structure were also examined.
Three to six-week-old Zinnia elegans were grown Hoagland's solution containing different concentrations of cadmium from one to two weeks. Atomic absorption spectroscopic studies showed that the distribution of cadmium was mainly in root. The accumulation of cadmium in stems was higher than that of in leaves. In leaves, the ability of cadmium accumulation in young leaves was much higher than that of old leaves.
Calcium Distribution and Accumulation in Ovules of Plumbago Zeylanica
Authors: Zhu Hua , Russell Scott D 
Published: July 2020

Abstract
The embryo sac (ES) of Plumbago zeylanica, unlike most other flowering plants, lacks synergidsthe cell type that usually receives the pollen tube and the male gametes. Normally, synergids store copious amounts of calcium, estimated to exceed 15% by weight; this is believed to attract pollen tubes, which penetrate the ES, and may trigger the release of the sperm cells within one of the two synergids. If high concentrations of calcium are truly required for fertilization, the ES of Plumbago should also contain significant quantities. Synergids in normal flowering plants are preprogrammed for cell death, receiving the contents of the pollen tube directly in their cells, whereas synergid-lacking angiosperms apparently do not have such an apoptotic cell in the ES. Potassium pyroantimonate labeling was used to localize principally loosely-bound calcium, because it is a relatively mobile form of the Ca2+ ion that is available for redistribution during fertilization events.
Detection of Calcium in the Adhesive Material Obtained from the Plant Pathogen Colletotrichum Graminicola'. X Ray Microanalysis (Eds) Evidences
Authors: Leite B , Ishida ML , Alves E , Pascholati SF , Sugui JA 
Published: July 2020

Abstract
The appressoria formation of Colletotrichum graminicola was monitored by scanning electron microscopy (SEM) coupled with an X Ray microanalysis system (EDS - Oxford Instrument LINK ISIS). Recently formed appressoria, an infection structure of plant pathogenic fungi, firmly glues itself to an artificial surface (polystyrene) as a consequence of the production of an adhesive material (AM). The nature of this material was already demonstrated to be mainly constituted of a glycoprotein (Sugui et al, PMPP, 1998). The objective of this work was to verify the involvement of divalent ions, specially calcium, in the process as whole.
The AM was isolated and purified from conidia that germinated on polystyrene Petri dishes. The primary AM was dialyzed against three liters of distilled water before being lyophilized. Subsequently, the material was placed on top of a carbon tape and observed by scanning electron microscopy under high vacuum (Fig. 1 and 2A). On the other hand, the same material was submitted to X Ray microanalysis without coating.
Room Temperature Dewetting of Polymer Thin Films Investigated by AFM and Low Voltage SEM
Authors: Leonard DN , Batchelor AD , Spontak RJ , Russell PE 
Published: July 2020

Abstract
Thin films (&lt;100nm) of diblock copolymers are being investigated for various applications including templates for nanopatterning [1], electronic packaging materials, and biomedical applications. In such applications it is essential that stable defect free films be produced repeatedly. Because long and short range forces (like van der Waals) dominate thin polymer films, instabilities are introduced in the films when they are spin-coated onto hydrophobic substrates resulting in dewetting of the film from the substrate. Dewetting is initiated at a nucleation site in a metastable film leading to the formation of a dry patch and proceeds to grow by transport of material away from the nucleation site, forming a lip that surrounds the hole. Highly symmetrical structures form during progression of the dewetting process and completion of the process can be identified when all holes coalesce forming polygons outlined by droplets of the polymer film [2].
Characterizing Interfacial Fracture Toughness Using AFM
Authors: Li M , Carter CB , Hillmyer MA , Gerberich WW 
Published: July 2020

Abstract
Reliability of thin polymer films is strongly dependent on interfacial adhesion. This paper concerns the application of indentation combined with atomic force microscopy (AFM) for the evaluation of polymer-non-polymer adhesion. Interfacial toughness calculations have been made using AFM measurement of geometry of delaminations induced by indentation. Fracture surfaces characterized with AFM are also presented here.
The interface chosen for study is that between polystyrene (PS) and a glass substrate. Spin coating has been used to prepare PS films. PS, dissolved in toluene, was spun onto the soda-lime glass and then dried at 60°C for 3h to remove residual solvent. The thickness of the PS film was approximately 660nm. To enhance the driving force for delamination, poly(methyl methacrylate) (PMMA) overlayers were applied on top of the PS films. The PMMA overlayer, of thickness approximately 1.5 μm, was first solvent cast onto a second glass slide, floated off the glass onto deionized water, and then laid on top of a first glass substrate which had been coated with PS.
Imaging Electrochemical Controlled Chemical Gradients Using Pulsed Force Mode Atomic Force Microscopy
Authors: Fried G , Balss K , Bohn P W 
Published: July 2020

Abstract
The electrochemical formation of gradients in self assembled monolayers has been demonstrated recently [1]. The capacity to image these gradients provides useful information on the physical chemistry of electrochemical striping.
Imaging chemical gradients requires the ability to sense the chemical moiety on the top of the self-assembled monolayer. This has been accomplished by derivatizing an atomic force microscope (AFM) tip with molecules selected to have specific interactions with the sample in a technique known as chemical force microscopy [2]. Typical tapping mode AFM is then used to image the sample; the tip is oscillated vertically above the sample and the tip-sample interaction modulates the amplitude of the tip.
The sample adhesion, sample stiffness, and sample topography all influence the oscillation amplitude of the tip. Pulsed Force Mode (PFM) [3] is an extension for atomic force microscopes. The PFM electronics introduces a sinusoidal modulation to the z-piezo of the AFM with an amplitude between 10 to 500 nm at a user selectable frequency between 100 Hz and 2 kHz.
Performance Data of a New 2048 X 2048 Pixel Slow-Scan CCD Camera For TEM
Authors: Hiller SA , Kabius B , Probst W , Tröster H , Trendelenburg M , Crucifix C , Tröndle A 
Published: July 2020

Abstract
Excellent linearity and high sensitivity have made SSCs the ideal image detector for almost every TEM application. Their ability to make high quality digital images available within fraction of seconds for further evaluation and processing in a PC, have made them a non-dispensable accessory for any modern TEM. However, despite their excellent characteristics, SSCs provide a restricted number of individual image points in respect to a negative, what is considered to be the main disadvantage of this detector. To compensate for this, CCDs with 2048x2048 pixel are available since some time. SSCs using these 2kx2k CCD arrays not only provide 4 times the pixel number but also offer a lot more options people have waiting for: e. g. highly resolved low-dose or ESI images with significantly improved signal to noise ratio, or higher resolved images for diffraction analysis and holographic reconstruction.
Electron Decelerator for Improved CCD Performance In Intermediate Voltage Electron Microscopy
Authors: Downing Kenneth H , Favia Paola , Mooney E 
Published: July 2020

Abstract
There are many advantages of IVEMs over more conventional microscopes, all of which make it possible to obtain more accurate data at higher resolution. One significant drawback of higher accelerating voltages is degraded performance of the electron detector, a problem that is particularly serious with CCD cameras. At any voltage, one faces a tradeoff with the CCD performance between sensitivity and resolution. Electron scattering within the scintillator and its support broaden the point spread function, while the decreased scattering cross section at higher voltages decreases the light output from the scintillator. At voltages much above 100 kV these effects have been found to seriously limit CCD performance. With the trend towards electronic data collection and microscope automation, it is essential that a high performance detector be developed for the IVEM. One approach to optimizing the performance tradeoff employs lens coupling to improve resolution, at the expense of sensitivity.
Microcalorimeter EDS: Benefits and Drawbacks
Authors: Wollman D A , Newbury Dale E , Nam S W , Hilton G C , Irwin K D , Rudman D A , Deiker S , Bergren N F , Martinis John M 
Published: July 2020

Abstract
The commercial introduction of high-count-rate, near-room-temperature silicon drift detectors (presently available) and high-energy-resolution cryogenic microcalorimeters (forthcoming) is an exciting development in x-ray microanalysis, in which detector choices and capabilities have been essentially stable for many years. Both of these new energy-dispersive detectors promise improved capabilities for specific applications, e.g., faster EDS mapping (silicon drift detectors) and nanoscale particle analysis (microcalorimeters). In this paper, we briefly examine some of the important benefits and drawbacks of microcalorimeter EDS (μcal EDS) for x-ray microanalysis.
The primary benefit of μcal EDS over conventional semiconductor EDS is the factor of ∼ 20 improvement in energy resolution (∼ 4 eV, real-time analog signal processing), as shown in Figure 1.
Cryodetectors for High Resolution X-Ray Spectroscopy
Authors: Höhne Jens , Bühler Matthias , Hertrich Theo , Hess Uwe 
Published: July 2020

Abstract
Based on excellent energy resolution and single quantum detection sensitivity, cryodetectors are offering a variety of new, analytical solutions for the analysis of elementary surface compositions, especially for the analysis of light elements and very small sized structures. Cryodetectors operate typically at temperatures between 30 and 200mK and require vibration free and fully automated cooling systems in order to qualify for industrial applications. Cryodetectors are low temperature superconductors where the two most prominent types are based on microcalorimeter and tunnel diode principles. Cryodetectors are mainly employed for surface analysis applications as energy dispersive X-ray spectrometers with energy resolutions of less than 15eV, but may also be used as highly sensitive UV, VIS or even mass spectrometers in the future.
Conventional EDX detectors are semiconductors. An impinging X-ray quantum creates a number of electronhole pairs dependent on the energy of the triggering event thus allowing energy dispersive measurements. The performance limit of semiconductor detectors has almost been reached and is determined by the excitation energy necessary to create electron-hole pairs.
The Characterization of Nano Materials in the FE-SEM
Authors: Gauvin Raynald , Horny Paula 
Published: July 2020

Abstract
The observation of nano materials or nano phases is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the last decade, a new generation of microscopes is available on the market. These are the Field Emission Scanning Electron Microscope (FE-SEM) with a virtual secondary electron detector. The FE-SEM have a higher brightness allowing probe diameter smaller than 2.5 nm with incident electron energy, E0, below 5 keV. Furthermore, what gives FE-SEM outstanding resolution is the virtual secondary electron (SE) detector. The virtual SE detector is located above the objective lens and it is also named a through-the-lens (TTL) detector. Therefore, the SE images are mostly made up of all SE of type I and II, because those of type III, which are generated by the backscattered electrons in the chamber, are not collected.
Development of an Ultra-High Resolution In-Lens FESEM
Authors: Sato Mitsugu , Kageyama Kaneo , Nakagawa Mine 
Published: July 2020

Abstract
Aside from the electron column, there are many factors that determine image quality in an ultra high resolution Field Emission Scanning Electron Microscope (FESEM). To obtain quality images, the operator must minimize sample contamination and be able to select the appropriate signal generated from the sample surface. Hitachi has developed a new in-lens FESEM that both minimizes surface contamination and improves signal efficiency.
Sample contamination is reduced by incorporating an oil free vacuum system, consisting of a 300 1/s turbomolccular pump and a 200 1/min scroll pump. For demanding applications, an additional 50 1/s turbomolccular pump can be added to back the main high vacuum pump. Furthermore, sample contamination caused by electron beam irradiation has been reduced by employing a high speed electrostatic beam blanking system. By blanking the beam during scan retrace (flyback), the electron dose accumulated on the sample can be minimized.
Low Voltage Biological X-Ray Microanalysis: Progress and a Remaining Problem
Authors: Echlin Patrick 
Published: July 2020

Abstract
Experimental work in a number of research groups over the past five years have demonstrated, unequivocally, that low voltage i.e. 5kV and below, quantitative x-ray microanalysis is a valid analytical technique which can be applied to a wide range of specimens. The advantages of this approach are now generally well known and include improved image contrast, diminished bulk charging of the sample and for bulk specimens, a reduction in the size of the beam-sample interactive volume from which the x-rays are generated, and as a consequence, a considerable improvement in the microanalytical spatial resolution. In addition, low voltages ensure a sensitive surface analysis procedure which provides true topographic contrast and that in the case of light element analysis, quantitation is simplified because the atomic number (Z), absorption (A) and fluorescence (F) effects are minimised. All these advantages are improved further if one uses a field emission gun as the primary electron source.