bluuebunny/crossref_metadata_2025 huggingface dataset:
Patient experiences of an electronic PRO tailored feedback system for symptom management following upper gastrointestinal cancer surgery
Authors: Richards H. S. , Portal A. , Absolom K. , Blazeby J. M. , Velikova G. , Avery K. N. L.
Published: June 2020

Purpose

Complications following upper gastrointestinal (UGI) surgery are common. Symptom-monitoring following discharge is not standardized. An electronic patient-reported outcome (ePRO) system providing feedback to patients and clinicians could support patients and improve outcomes. Little is known about patients’ experiences of using such systems. This qualitative sub-study explored patients’ perspectives of the benefits of using a novel ePRO system, developed as part of the mixed methods eRAPID pilot study, to support recovery following discharge after UGI surgery.

Methods

Patients completed the online ePRO symptom-report system post-discharge. Weekly interviews explored patients’ experiences of using ePRO, the acceptability of feedback generated and its value for supporting their recovery. Interviews were audio-recorded and targeted transcriptions were thematically analysed.

Results

Thirty-five interviews with 16 participants (11 men, mean age 63 years) were analysed. Two main themes were identified: (1) reassurance and (2) empowerment. Feelings of isolation were common; many patients felt uninformed regarding their expectations of recovery and whether their symptoms warranted clinical investigation. Participants were reassured by tailored feedback advising them to contact their care team, alleviating their anxiety. Patients reported feeling empowered by the ePRO system and in control of their symptoms and recovery.

Conclusion

Patients recovering at home following major cancer surgery regarded electronic symptom-monitoring and feedback as acceptable and beneficial. Patients perceived that the system enhanced information provision and provided a direct link to their care team. Patients felt that the system provided reassurance at a time of uncertainty and isolation, enabling them to feel in control of their symptoms and recovery.
Scent marking in wolves Canis lupus inhabiting managed lowland forests in Poland
Authors: Stępniak Kinga M. , Niedźwiecka Natalia , Szewczyk Maciej , Mysłajek Robert W.
Published: June 2020

In wolves Canis lupus, scent marking plays an important role in territory defence. In Europe, studies on patterns of scent marking in wolves have mostly been conducted in mountains or primeval forests, but since these areas are characterised by low human activity, the impact of people on this behaviour has been neglected. We conducted a study that combined genetic methods with an analysis of the spatial distribution of wolf territory markings in lowland managed forests with high human activity. We found that scent markings are deposited by all members of wolf family groups. Wolves most intensively marked crossroads and their vicinity, especially on roads only accessible for four-wheel drive cars. Our study provides further evidence that crossroads of forest roads play a crucial role in wolf scent marking. The results of our study may be useful during inventories of wolf populations based on collecting indirect signs of their presence or non-invasive genetic sampling.
Using aggregated data from Swedish national quality registries as tools to describe health conditions of older adults with complex needs
Authors: Johansson Linda , Finkel Deborah , Lannering Christina , Aslan Anna K. Dahl , Andersson-Gäre Boel , Hallgren Jenny , Lindmark Ulrika , Bravell Marie Ernsth
Published: June 2020

Background

Combining National Quality Registries (NQRs) with existing National Health Registries (NHRs) might make it possible to get a wider picture of older adults health situation. The aim was to examine the feasibility of aggregating data across different NQRs and existing NHRs to explore the possibility to investigate trajectories and patterns of disease and care, specifically for the most ill older adults.

Method

A Swedish twin population (N = 44,816) was linked to nine NQRs and four NHRs. A descriptive mixed-method study was performed. A manifest content analysis identified which health parameters were collected from each NQR. Factor analysis identified patterns in representation across NQRs. Two case studies illustrated individual trajectories of care by using NQRs and NHRs.

Results

About 36% of the population was registered in one or more NQRs. NQRs included 1849 variables that were sorted into 13 categories with extensive overlap across the NQRs. Health and function variables were identified, but few social or cognitive variables. Even though most individuals demonstrated unique patterns of multi-morbidities, factor analysis identified three clusters of representation in the NQRs with sufficient sample sizes for future investigations. The two cases illustrated the possibility of following patterns of disease and trajectories of care.

Conclusions

NQRs seem to be a significant source for collecting data about a population that may be underrepresented in most research on aging because of their age and poor health. However, NQRs are primarily disease related, and further development of the registries to maximize coverage and utility is needed.
Outcomes on safety and efficacy of left atrial appendage occlusion in end stage renal disease patients undergoing dialysis
Authors: Genovesi Simonetta , Porcu Luca , Slaviero Giorgio , Casu Gavino , Bertoli Silvio , Sagone Antonio , Buskermolen Monique , Pieruzzi Federico , Rovaris Giovanni , Montoli Alberto , Oreglia Jacopo , Piccaluga Emanuela , Molon Giulio , Gaggiotti Mario , Ettori Federica , Gaspardone Achille , Palumbo Roberto , Viazzi Francesca , Breschi Marco , Gallieni Maurizio , Contaldo Gina , D’Angelo Giuseppe , Merella Pierluigi , Galli Fabio , Rebora Paola , Valsecchi Mariagrazia , Mazzone Patrizio
Published: June 2020

Background

In patients with end stage renal disease and atrial fibrillation (AF), undergoing chronic dialysis, direct oral agents are contraindicated and warfarin does not fully prevent embolic events while increasing the bleeding risk. The high hemorrhagic risk represents the main problem in this population. Aim of the study was to estimate the safety and efficacy for thromboembolic prevention of left atrial appendage (LAA) occlusion in a cohort of dialysis patients with AF and high hemorrhagic risk.

Methods

Ninety-two dialysis patients with AF who underwent LAA occlusion were recruited. For comparative purposes, two cohorts of dialysis patients with AF, one taking warfarin (oral anticoagulant therapy, OAT cohort, n = 114) and the other not taking any OAT (no-therapy cohort, n = 148) were included in the study. Primary endpoints were (1) incidence of peri-procedural complications, (2) incidence of 2-year thromboembolic and hemorrhagic events, (3) mortality at 2 years. In order to evaluate the effect of the LAA occlusion on the endpoints with respect to the OAT and No-therapy cohorts, a multivariable Cox regression model was applied adjusted for possible confounding factors.

Results

The device was successfully implanted in 100% of cases. Two major peri-procedural complications were reported. No thromboembolic events occurred at 2-year follow-up. The adjusted multivariable Cox regression model showed no difference in bleeding risk in the OAT compared to the LAA occlusion cohort in the first 3 months of follow-up [HR 1.65 (95% CI 0.43–6.33)], when most of patients were taking two antiplatelet drugs. In the following 21 months the bleeding incidence became higher in OAT patients [HR 6.48 (95% CI 1.32–31.72)]. Overall mortality was greater in both the OAT [HR 2.76 (95% CI 1.31–5.86)] and No-Therapy [HR 3.09 (95% CI 1.59–5.98)] cohorts compared to LAA occlusion patients.

Conclusions

The study could open the way to a non-pharmacological option for thromboembolic protection in dialysis patients with AF and high bleeding risk.
Learners’ perceptions and experiences of studying psychology online
Authors: Garip Gulcan , Seneviratne Sanju Rusara , Iacovou Susan
Published: June 2020

This study aimed to explore the lived experiences of six international and mature online learners studying on an undergraduate psychology course to identify barriers and facilitators to studying online. A secondary aim was to deductively explore the applicability of the Capability, Opportunity, Motivation, and Behaviour model to participants' narratives related to self-regulated online learning. Online interviews with six demographically diverse participants were conducted and analysed using Interpretative Phenomenological Analysis. The overarching theme was 'the balancing act of online learners', which consisted of three major themes (and respective subthemes): (1) 'identity as an online learner' ('in today's world, we're all very busy'), (2) 'access to resources' ('importance of location' and 'comparing online to on-campus teaching and learning'), and (3) 'changing nature of social interactions' ('tutors as a crutch' and 'peer-to-peer interactions'). A number of facilitators and barriers related to these themes were identified, which are applicable to the COM-B model. The COM-B model offers a novel approach in designing and delivering learning materials and activities that may instil or help maintain self-regulated learning in online psychology students.
Psychometric analysis of forensic examiner behavior
Authors: Luby Amanda , Mazumder Anjali , Junker Brian
Published: June 2020

Forensic science often involves the comparison of crime-scene evidence to a known-source sample to determine if the evidence and the reference sample came from the same source. Even as forensic analysis tools become increasingly objective and automated, final source identifications are often left to individual examiners’ interpretation of the evidence. Each source identification relies on judgements about the features and quality of the crime-scene evidence that may vary from one examiner to the next. The current approach to characterizing uncertainty in examiners’ decision-making has largely centered around the calculation of error rates aggregated across examiners and identification tasks, without taking into account these variations in behavior. We propose a new approach using IRT and IRT-like models to account for differences among examiners and additionally account for the varying difficulty among source identification tasks. In particular, we survey some recent advances (Luby 2019a) in the application of Bayesian psychometric models, including simple Rasch models as well as more elaborate decision tree models, to fingerprint examiner behavior.
2019 novel‐coronavirus: Cardiovascular insights about risk factors, myocardial injury, therapy and clinical implications
Authors: Cappannoli Luigi , Scacciavillani Roberto , Iannaccone Giulia , Anastasia Gianluca , Di Giusto Federico , Loria Valentina , Aspromonte Nadia
Published: June 2020

From December 31st, 2019, a novel highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), has spread worldwide, reaching at present the dimension of a pandemic. In addition to damaging the lungs, SARS‐CoV‐2 may also damage the heart and this is corroborated by the evidence that cardiovascular comorbidities are associated with a higher mortality and poor clinical outcomes in patient infected by the virus. During the infection myocardial injury, myocarditis and arrhythmias have also been reported, but the pathophysiological mechanisms of these complications are yet to be understood. Great attention is also being posed on the potential beneficial/harmful role of angiotensin converting enzyme (ACE) inhibitors, as far as the virus binds to ACE2 to infect cells, but evidences lack. Furthermore, SARS‐CoV‐2 can also affect the aspect of acute coronary syndromes, not only because these two distinct pathological entities share pathogenic aspects (such as the systemic inflammatory state and cytokine release), but also and above all for the consequences that the need to contain the infection has on the management of cardiological urgencies. The aim of this review was therefore to summarize the relationship between the virus and the cardiovascular system.
Serum expression of microRNA-16 in a cohort of Egyptian patients with ulcerative colitis and its correlation with disease extent and severity
Authors: Saad Hussein Mahmoud , Ali Ezzat , Baddour Nahed , Ibrahim Mohamed Eid , Tayae Eman
Published: June 2020

Ulcerative colitis is one of the IBDs. Its etiology and pathogenesis remain undefined with an interaction between environmental, genetic and immunological factors is the most accepted explanation. Several recent studies have examined microRNA expression in the peripheral blood and tissues from IBD patients. The study aims at assessing the expression of serum miR-16 in ulcerative colitis patients and its correlation with disease extent, activity and severity. It included 30 treatment naїve ulcerative colitis patients of different presentations. Serum miR-16 expression was assessed using reverse transcriptase quantitative real time PCR (RT-qPCR), and then correlated with that of a group of 20 healthy subjects to assess its role in diagnosis of ulcerative colitis. Also, it was correlated with disease extent (proctitis, left sided colitis, extensive colitis) and disease activity and severity indices (Truelove and Witts criteria, fecal calprotectin and UCEIS). Thirty ulcerative colitis patients were enrolled, 53% had mild, 37% had moderate, while 10% had severe disease. Concerning endoscopic extent, 8 had proctitis, 14 had left sided colitis and 8 had extensive colitis. Serum expression of miR-16 in the 30 patients were compared to that of the healthy control subjects. The patients’ group showed median serum miR-16 expression of 1.91, 1.13 for the control group with a significant difference between both groups. Correlation between serum miR-16 expression with disease extent, activity and severity showed no significant relation. From the current study we can conclude that increased serum expression of miR-16 is associated with ulcerative colitis despite no significant relation to disease activity extent or severity.
A more conclusive and more inclusive second derivative test
Authors: Skurnick Ronald , Roethel Christopher
Published: June 2020

Given a differentiable function f with argument x, its critical points are those values of x, if any, in its domain for which either f′ (x) = 0 or f′ (x) is undefined. The first derivative test is a number line test that tells us, definitively, whether a given critical point, x = c, of f(x) is a local maximum, a local minimum, or neither. The second derivative test is not a number line test, but can also be applied to classify the critical points of f(x). Unfortunately, the second derivative test is, under certain conditions, inconclusive.
Electron Microscopy of Carcinomas of the Lung
Authors: Mackay B. , Mandavia M. , Lukeman J. M. , Mountain C. F.
Published: June 2020

Carcinoma of the lung is the most common malignant neoplasm in males and the incidence continues to rise. The inadequacy of current methods of treatment is reflected in the poor prognosis: only 5% of patients survive for more than five years following diagnosis.

In order to assess the effectiveness of new therapeutic modalities, accurate pathologic diagnosis is essential, and it is recognized that a proportion of these tumors can not be accurately classified by light microscopy alone. We have now studied over one hundred lung carcinomas with correlated light and electron microscopy, and our findings indicate that electron microscopy can be an invaluable aid in the diagnosis and classification of the tumors. Study of the fine structure of the tumor cells can provide the basis for a more precise classification than is currently used in clinical studies, and additionally give insight into problems of histogenesis.
Ultrastructural Evaluation of Parathyroid Glands from Bulls with Ultimobranchial Thyroid Tumors
Authors: Yarrington J. T. , Capen C. C. , Black H. E.
Published: June 2020

A syndrome of ultimobranchial thyroid tumors (UTT) of aged bulls shares many characteristics with medullary thyroid carcinoma in man (Black et al. Cancer 32:867-878, 1973). Multiple endocrine tumors (pheochromocytomas, pituitary adenomas) and severe skeletal disease (vertebral osteosclerosis with ankylosing spondylosis and degenerative osteoarthrosis) often are detected coincidentally in bulls with UTT. Parathyroid hyperplasia or chief cell adenomas have been reported to occur frequently in humans with familial medullary thyroid carcinoma. However, parathyroid gland activity in bulls with UTT has not been well characterized. The objectives of this investigation were: (1) to investigate the histopathologic and ultrastructural alterations in parathyroid glands of bulls with UTT compared to control bulls of the same age range without C-cell tumors, and (2) to correlate these morphologic findings in the parathyroids with changes in serum calcium, phosphorus, and immunoreactive parathyroid hormone.
Ependymal Response in Acute Cerebral Infarction
Authors: Dodson Ronald F. , Tagashira Yukio
Published: June 2020

The ependymal complex (subependymal, ependymal, and supraependymal) forms the complex sheath which separates brain parenchyma from ventricular contents. This structure forms a functionally less efficient counterpart to the blood-brain-barrier. That area of the ependymal lining which separates the caudate nucleus from the cavity of the lateral ventricle has recently been described in the adult squirrel monkey. This area was of particular interest since the underlying brain tissue was shown to be of great susceptibility to periods of ischemic as well as hypoxic/ischemic insults.
Lattice Images of Biological and Synthetic Apatites
Authors: Spector M.
Published: June 2020

Lattice images obtained from high resolution transmission electron microscope studies of human calcified tissues and synthetic calcium phosphates were utilized to correlate the structures of biological and synthetic apatites. Lattice spacings appearing in the Fourier images of crystallites in bone and calcified atherosclerotic plaque were comparable to the spacings seen in lattice images of synthetic hydroxyapatite crystallites.
Hela Cell Surface Alkaline Phosphatase
Authors: Fiskin A. Max , Melnykovych G. , Peterson G. , Mack P.
Published: June 2020

We have shown electronmicroscopically that HeLa Cell lines S3K and S3G undergo parallel changes in the morphology and composition of their cell surfaces when exposed to prednisolone. In response to this glucocorticoid derivative the clonal HeLa behave as if the property of contact inhibition is restored. A striking biochemical change characterizing this response is induction (S3G) or repression (S3K) of alkaline phosphatase activity. Interpretation of these changes rest in part on the amount and nature of the enzyme activity residing on the cell surface. Here we show that HeLa Cell surface alkaline phosphatase can be visualized in replica, and correlate this enzyme activity with specific surface features. A Gomori stain for alkaline phosphatase was combined with surface replication, using the approach described for visualizing lanthanum binding sites in replica.
Internal Membranes in the Nitrogen Fixing Organisms: Free-Living Azotobacter vinelandii and Rhizobium japonicum Bacteriods
Authors: Raveed D. , Reed D. W. , Toia R. E.
Published: June 2020

The free-living bacterium Azotobacter vinelandii carries out the fixation of molecular nitrogen under aerobic conditions. During growth at high oxygen concentrations, these bacteria exhibit high rates of both respiration and nitrogen fixation. Internal membranes are not easily seen in sections of intact bacteria but an extensive intracellular membrane system is apparent in osmotically-lysed cells (Fig. 1). Equilibration of the cells with 0.3 M glycerol and rapid dilution into ten volumes of 0.01 M Tris-HCl buffer, pH 7.4, permits the escape of electron dense cytoplasmic material. These intracellular membranes which contain the respiratory components of the cell are spherical invaginations of the cytoplasmic membrane and are completely separable from the smaller vesicular azotophore membranes which contain the nitrogenase in A. vinelandii.
Ultrastructure of Some Planktonic Formainifera
Authors: Zucker William H.
Published: June 2020

Planktonic foraminifera are widely-distributed and abundant zooplankters. They are significant as water mass indicators and provide evidence of paleotemperatures and events which occurred during Pleistocene glaciation. In spite of their ecological and paleological significance, little is known of their cell biology. There are few cytological studies of these organisms at the light microscope level and some recent reports of their ultrastructure.

Specimens of Globigerinoides ruber, Globigerina bulloides, Globigerinoides conglobatus and Globigerinita glutinata were collected in Bermuda waters and fixed in a cold cacodylate-buffered 6% glutaraldehyde solution for two hours. They were then rinsed, post-fixed in Palade's fluid, rinsed again and stained with uranyl acetate. This was followed by graded ethanol dehydration, during which they were identified and picked clean of debris. The specimens were finally embedded in Epon 812 by placing each organism in a separate BEEM capsule. After sectioning with a diamond knife, stained sections were viewed in a Philips 200 electron microscope.
Electron Microscopic Cytochemical Demonstration of Heterogeneity of Mitochondria with Respect to the Activity of Different Oxidoreductases
Authors: Hanker J. S. , Moore H. G. , Preece J. W.
Published: June 2020

Ultrahistochemical methods have only occasionally been used to demonstrate a heterogeneity of intracellular mitochondria. Methods have recently become available, however, for the direct demonstration of oxidoreductases such aa cytochrome oxidase (CYO), lactate dehydrogenase (LDH) and NADH dehydrogenase (NADHDH), in formalin-fixed tissues. By assessment of oxidoreductase activity at different parts of the electron transport system, an indication of the relative metabolic competence of mitochondria may be obtained.
Dipotassium Tetramethyl Osmate: A New Stain for Electron Microscopy
Authors: Murphy Juith A. , Hinckley C.C.
Published: June 2020

Methonal solutions of dipotassium tetramethyl osmate (DTMO) have ben found to be effective general stains in ultrastructure studies of plant and fungal tissue. The contrast produced by the stain, though broadly similar to that produced by lead citrate, reveals some elements of cell structure not usually seen in the outer cell walls of fungi. DTMO is also without troubling precipitate problems, and in general, less preparatory and washing steps and fewer neccessary precautions. Additionally, region specific precipitates are found in DTMO stained sections of fungi and algae, possibly indicative of chemical reactions between DTMO and reduced cell compenents.
Use of Enterovirus Typing Pools for Immuno-Electron Microscopy
Authors: Amstein C. F. , Hartman P. A.
Published: June 2020

The most common viruses found in foods are the enteroviruses, which because of the large number of serotypes and lack of group antigens, require the use of individual antisera to identify each virus. The standardized Lim Benyesh-Melnick enterovirus typing pools, distributed by the NIH, reduce the number of tests required to identify most of the enteroviruses of human origin. The 8 pools are capable of identifying 37 enteroviruses. We have adapted these typing pools for immuno-electron microscopy (IEM), to replace more timeconsuming serological tests.
Rhabdovirus-like Particles in Stunted Maize from Texas and Hawaii
Authors: Bradfute O. E. , Robertson Diane C.
Published: June 2020

Maize stunting diseases in the U. S. have been associated with flexuous rod and isometric virus particles, as well as mycoplasma-like bodies as causal agents. Maize mosaic is a stunting disease first reported in Hawaii and subsequently found in the Caribbean region, India and Mauritius. The pathogenic agent is persistently transmitted by the leafhopper Peregrinus maidis (Ashm.). Electron microscopy of maize mosaic infected leaves and infective leafhoppers has revealed rhabdoviruses. Neither the maize mosaic disease nor a rhabdovirus-associated stunting disease of maize have been reported in the continental U. S.
Transmission Microscopy at Atomic Dimensions
Authors: Krakow William
Published: June 2020

For the best transmission electron microscopes now available, the phase contrast mechanism must be used in the interpretation of the optical imaging process producing high resolution micrographs. In the following paragraphs, some techniques are discussed which minimize image degradation and yield improvements in resolution and/or contrast so that the information content in the image can be clearly displayed.
High Resolution Imaging in Bright and Dark Field at High Voltages
Authors: Chen L. J. , Seshan K.
Published: June 2020

The weak beam dark field and high order bright field imaging(2) methods are powerful means for improving the resolution of images detected by diffraction contrast. However, at high voltages, many beam interactions become important as more interband transitions occur between different Bloch waves. At the exact Bragg condition, for any order reflection, usually more than two interband transitions are important for both weak beam and bright field images, and complicated images result.
Correlation Between Inelastic Electron Scattering and Secondary Electron Production
Authors: Voreades D. , Crewe A. V.
Published: June 2020

The mechanism of secondary electron production is currently under investigation in our laboratory. The present work is concerned with the correlation between an energy loss event and the production of a secondary.

The idea behind the experiment is that the energy needed for the production of a secondary electron by electron bombardment can only be provided by the impinging one. On the other hand, it is well known that these electrons experience characteristic energy losses when they pass through a specimen. Characteristic energy losses of various substances are of great interest since they provide important information about the specimens. Consequently we want to find out how one can correlate a characteristic energy loss with the production of'a secondary electron.
Interfacial Diffusion Effects in Au-Cu Bicrystals
Authors: Macur J. E. , Vook R. W.
Published: June 2020

An experimental study was undertaken to determine what effect interdiffusion would have on the microstructure of Au-Cu bicrystals. This system was chosen because the materials are completely miscible in the solid state and form ordered structures below certain critical temperatures.
Induction and Differentiation of Dental Epithelium in Vivo and in Vitro
Authors: Kollar E. J.
Published: June 2020

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.
Electron Microscopic Image Processing in the Classification and Quantitation of Human Glial Tumor Cell Properties
Authors: Smith B. H. , Ellis J. R. , Robinson A. , Greenwood M. A. , Pleasants E. R. , Cooke C. , Kornblith P. L.
Published: June 2020

Cell lines derived from human glial tumors studied in vitro offer the opportunity for the study of a variety of the basic biological parameters of these cells as well as their specific reactions to different classes of chemotherapy and cellular and humoral immunological reagents. For example, it has been possible to show that there are both BCNU-resistant and sensitive glioma cell lines in vitro and that sensitive cells exhibit a series of shape and membrane changes not shown by resistant cells. In addition, use of human fibroblast interferon or superinduced-autologously-produced glioma cell interferon at 1CP - 104 units/ml causes a modest decrease in the growth rate of many glioma cell lines as well as more striking morphological changes suggestive of a tendency toward a more “differentiated” state.
Electron Microscopic identification of Pre-B Lymphocytes in the Bone Marrow of a Patient with Chronic Myelocytic Leukemic in Blast Crisis
Authors: Mullin T. , Yee G. , Aheam M. , Trujillo J.
Published: June 2020

There have been numerous reports in the current literature suggesting that hematopoietic precursor cells in some human chronic myelocytic leukemias (CML) undergo lymphoblastic transformation at the time of the acute blast crisis (BC) stage. The primary evidence offered in support of this transformation theory--lymphoblastic appearing morphology, increased terminal deoxynucleotidyl transferase (TdT) activity, and chemotherapeutic sensitivity to vincristine and prednisone--has been indirect, however, since these features may occur in nonlymphoid cells. More direct support for the Pre-B lineage of these cells has recently been provided by immunofluorescent light microscopic studies demonstrating the presence of intracytoplasmic immunoglobulin M (IgM) in these CML-BC cells.
Arrays of Paired Helical Filaments in Alzheimer's Disease
Authors: Metuzals J. , Montpetit V. , Clapin D. F. , Nelson R. F.
Published: June 2020

Massive formations of paired helical filaments (PHF) found in neurons and in neurites of senile plaques are a characteristic diagnostic feature of Alzheimer's disease. Factors which initiate the formation of these highly regular structures are not known. However, their helical symmetry displays a basic principle of organization of the neurofilamentous network which is common to all neurons whether normal or pathological. The configuration of PHF assemblies may also be determined by principles common to all types of helical filaments of the cytoskeleton.
Low-Temperature Imaging for Biological Applications of High-Voltage Electron Microscopy
Authors: Fotino Mircea , Giddings Thomas H. , Voth Roland O. , Wray George P.
Published: June 2020

The devices and methodology required for applying low-temperature imaging to biological problems have been under development during the last few years at the Boulder HVEM Facility. The present report describes briefly the characteristics and preliminary performance of this endeavor.
Evaluation of in Vivo Adsorption of Plasma Proteins onto Hydrogel Coated Silicone Rubber by Scanning Electron Microscopy and Fourier Transform Infrared Spectroscopy
Authors: Miller Linda J. , Greer Raymond T.
Published: June 2020

Although there is considerable debate concerning the exact sequence of events that occur when blood contacts a foreign surface such as a polymer, most investigators agree on the basic sequence: polymer surfaceblood contact, competitive adsorption of plasma proteins, formation of protein coated surface, platelet approach, platelet reaction with glycoproteins, platelet adhesion, thrombus and coagulation.
SEM/EDX Microanalysis of Chlorinated Cake Flour Particles: Initial Study
Authors: Thomas Richard S.
Published: June 2020

Gaseous chlorine treatment has long been used commercially to improve the baking performance of cake flours. For reasons not well understood, cakes from treated flour usually have finer texture, and don't “fall” when removed from the oven. Recently, the safety of chlorine as a food additive has been questioned, and this commercial treatment may soon be banned. Search for alternative treatments has spurred research on how the added chlorine acts and, in particular, where this chlorine is located within the flour. Answers to the latter question have come previously only from bulk chemical analyses of heterogeneous flour fractions. Cake flour particles - including large endosperm chunks (fig. 1a), large (fig. 2a) and small starch grains and small fragments of lipoproteinaceous matrix material (fig. 3) “typically range in size from less than 1 to about 100μm; particles less than 3μm diameter represent only a very small fraction of total flour mass, however. For instrumental reasons, the present, initial study excluded these smallest particles.
The Uptake and Distribution of Potassium in Roots of Duckweed (Lemna Minor L) As Measured using Low Temperature X-Ray Microanalysis
Authors: Echlin Patrick , Lai Clifford , Hayes Thomas L.
Published: June 2020

Lemna minor L. plants were grown in a 14 H light and 10 H dark regime at 298 K in a medium containing 2 mM [K+]. Roots, 20 mm long and photosynthetically active, were removed and prepared for low temperature microscopy using methods described elsewhere. Fracture faces were made using the AMRAY Biochamber and the analysis carried out using an AMRAY 1000A SEM fitted with an LaB6 gun and a Kevex Si (Li) x-ray detector at 15-17 kV and a beam current of 1-2 nA. A reduced raster (1.0 μm2) was placed at the centre of the cell being analysed, care being taken to avoid any contact with the cell walls. Samples were maintained at 100-110 K throughout analysis and an LN2 cooled anti-contamination device was inserted close to the specimen. The spectra were analysed using the peak/background (P/B) ratio technique following use of background subtraction and peak de-convolution routines. Between eight and twelve fracture faces were analysed for each of the ten sites along the length of the root and the data pooled and presented in Table I.
The Microstructure of Explosively Loaded 304 Stainless Steel Flyer Plate
Authors: Johnson K. A. , Staudhammer K. P. , Murr L. E.
Published: June 2020

Flyer plates are used to impose pressure and pulse durations on specimens in explosively loaded systems. It is generally observed that significant changes in microstructure and microhardness are produced by this means. While the e ffect of shock loading on 304 stainless-steel has been investigated and shown to have a ϒ→α transformation, there have been no studies of the flyer plates. The major contribution which effects the flyer plate mirostructure is shock compression (resulting from explosive detonation) and the refracted shock wave after impact with the specimen assembly. The refracted shock waves has been addressed for the specimens. However, this has not been shown experimentally for the flyer plate. We looked at the microstructure of these flyer plates to answer questions raised regarding non-uniform shock fronts resulting from microstructural changes within the flyer-plate due to the shock event.
Electron Diffraction Study of Chrysotile Asbestos Soaked 10 Years in DD Water and Acid-Treated for up to 5 Days
Authors: Seshan K. , Millette J. R. , Smith G. R.
Published: June 2020

Chrysotile asbestos may enter drinking water from pipe erosion- or be present in the source from rock outcrops. This study was initiated to see what factors distinguish fresh chrysotile from old which has been exposed to water for prolonged times. Concomitantly, we investigated the effect of the exposure of chrysotile to IN HC1 and simulated gastric juices for up to 5 days. This was done to see if such an in-vitro exposure would cause changes in the chrysotile morphology and structure. Another parallel investigation studied in-vivo exposure.
The Composition of Ultra-Fine Coal Mineral Matter
Authors: Allen Robert M. , VanderSande John B.
Published: June 2020

The mineral matter in coal plays a deleterious role in coal combustion for power generation. Recent work has shown that the behavior of a pulverized coal fuel is determined not only by the composition of this mineral matter, but also by the size distribution of the mineral species. The present work involved the use of STEM to examine sub-100 nm-sized mineral particles and organically-bound elements in three different coals. The results were compared with results obtained using a microprobe equipped for the automated image analysis (AIA) of coal minerals in the >.2μm size range, and the results of a standard chemical analysis of high temperature ash of each coal.
The Accommodation of a Change in Grain Boundary Plane in Molybdenum
Authors: Kamenetzky E. A.
Published: June 2020

The accommodation of deformation at a grain boundary (GB) influences the mechanical and thermodynamical properties of the boundary. This paper focuses on the accommodation of a change in GB plane such as a GB step, GB faceting or GB curvature producing an effective change in the overall boundary plane. The stresses produced affect mechanical properties such as the continuation of plastic flow and the accommodation of an intergranular crack. Bcc materials are of interest because of the technological importance and because of the paucity of observations of bcc GB structure. Molybdenum is of particular interest because it shows an intrinsic GB brittleness.
The Effect of Specimen Thickness and Probe Size on Aem Analysis of Cr-Depletion Profiles in Sensitized Stainless Steel
Authors: Hall E. L.
Published: June 2020

Sensitization in stainless steels is caused by the formation of chromium-rich M23C6 carbides at grain boundaries, which depletes the adjacent matrix and boundary region of chromium, and hence leads to rapid intergranular attack. To fully understand the sensitization process, and to test the accuracy of theories proposed to model this process, it is necessary to obtain very accurate measurements of the chromium concentration at grain boundaries in sensitized specimens. Quantitative X-ray spectroscopy in the analytical electron microscope (AEM) enables the chromium concentration profile across these boundaries to be studied directly; however, it has been shown that a strong effect of foil thickness and electron probe size may be present in the analysis of rapidly-changing compositional gradients. The goal of this work is to examine these effects.
Faceted Twin Boundaries in an Mg-Al Spinel
Authors: Shaw T. M. , Carter C. B.
Published: June 2020

The atomic structure of grain boundaries is of fundamental importance in determining their behavior and thus the properties of polycrystalline materials. There have been several studies (eg. refs 1-4) of the detailed structure of pure tilt boundaries using lattice-fringe and structure imaging. These studies have mainly been concerned with metals and semiconductors. There have been some reports on the detailed structure of grain boundaries in ceramic materials (eg. 5,6) but most effort there has been directed towards identifying and understanding the nature of the thin amorphous layer which appears often to be present. The present paper presents results of a new study on the structure of twin boundaries in an Mg-Al spinel. The spinel studied is the non-stoichiometric MgO.2Al2O3 in which the oxygen atoms form an fcc sublattice and the cations sit in the tetrahedral and octahedral intersticies.
Effect of Thermal Treatment on Pt Crystallite Size for Pt/MgO Catalysts
Authors: Wanke S.E. , Klengler U. , Tesche B.
Published: June 2020

Supported catalysts containing Pt are widely used in the chemical industry and for the reduction of automobile emissions. The metal in these catalysts is present as small crystallites, and the metal surface area, which is related to the crystallite size, is one of the important properties. Decreases in metal area often occur during use, and some deactivated catalysts can be regenerated by treatment in O2 containing atmospheres. The nature of the support plays a crucial role in the regeneration (redispersion) process. Previous studies with Pt/MgO, in which H2 adsorption was used for measuring Pt areas, indicated that redispersion occurs for this system! However, chemisorption does not yield reliable results for systems with strong-metalsupport interactions (SMSI).
Multiple Cavity Disk Preparation for Transmission Electron Microscopy Combining Spark Machining and Electropolishing
Authors: Shaw G. Gordon
Published: June 2020

The usefulness of the disk technique for T.E.M. is extended by increasing the number of cavities in each disk. This result can be achieved, without sacrificing transmission area in each cavity, by the following means: A simple tool, as shown in Fig. 1, is made by drilling four 40-mil holes in a piece of 160-mil drill rod, and soldering in four 40-mil pieces of drill rod.

The disks are prepared from bulk material, 20 to 40 mils thick, by spark machining with a tubular brass tool to yield a disk approximately 160 mils in diameter. A disk is cemented to a brass block with a very thin layer of Duco cement. The block with mounted disk is placed on the platform of a spark machine and the tool shown in Fig. 1 is allowed to penetrate by spark erosion (using the fine cut) until 15 mils of metal remains between the face of the tool and the side of the disk mounted on the block. Fifteen mils is allowed for electropolishing to insure the removal of damage produced by spark erosion.
Cell Death in the Normal Epiphyseal Cartilage of the Rat
Authors: Fahmy Aly
Published: June 2020

The ultrastructure of the upper tibial epiphyseal cartilage plate of weanling and plateaued Sprague-Dawley rats growing under normal conditions has been studied, in order to establish a base-line for the future investigation of the site and mechanism of action of certain hormones which are known to affect the growth and maturation of long bones.

Observations have been made concerning the character and amount of the secretory products in the cells of the various zones, as well as the characteristics of the constituents of the intercellular matrix. Our findings have confirmed and amplified published observations on the ultrastructure of cartilaginous tissues in a variety of species in general.
Ultrastructure of Lymphatic Capillaries in the Transport of Colloidal Particles
Authors: Leak L. V. , Burke J. F.
Published: June 2020

The vital role played by the lymphatic capillaries in the transfer of tissue fluids and particulate materials from the connective tissue area can be demonstrated by the rapid removal of injected vital dyes into the tissue areas. In order to ascertain the mechanisms involved in the transfer of substances from the connective tissue area at the ultrastructural level, we have injected colloidal particles of varying sizes which range from 80 A up to 900-mμ. These colloidal particles (colloidal ferritin 80-100A, thorium dioxide 100-200 A, biological carbon 200-300 and latex spheres 900-mμ) are injected directly into the interstitial spaces of the connective tissue with glass micro-needles mounted in a modified Chambers micromanipulator. The progress of the particles from the interstitial space into the lymphatic capillary lumen is followed by observing tissues from animals (skin of the guinea pig ear) that were injected at various time intervals ranging from 5 minutes up to 6 months.
The Changing Phenomenon of Fibrillar Complex in Streptomyces Cinnamonensis
Authors: Chen Pearl Liu
Published: June 2020

It is generally recognized that (1) the nuclear region of the procaryotic organisms consists of randomly arranged fibrils, (2) the nuclear fibrils of bacteria may represent DNA or some material closely related to it, and (3) it is generally believed that the nuclear division of the procaryotic organisms is that of amitosis. The result of my recent investigation reveals that the fibrillar complex in the nuclear region exhibits a variety of configurations and change of position similar to the stages characteristic of chromosome movement in higher organisms.

The nuclear region of S. cinnamonensis consists of two distinct phases: a dense fibrillar complex and a less dense matrix in which the dense fibrillar complex is embedded. The dense fibrillar complex occurs in two main states, dispersed and compact. When in a dispersed condition the fibrillar phase exhibits a loose network (Fig. I), and when in a compact condition it appears as organized fibrils which in turn display a variety of configurations.
The Hitachi Model HU-11E High Performance Electron Microscope
Authors: Akabori H. , Asai T. , Katagiri S. , Komoda T.
Published: June 2020

Although we have been manufacturing present Model HU-11C Electron Microscope as a high performance electron microscope so far, we have recently completed new Model HU-11E high performance E. M. for the purpose of easier operation.
An Image Intensifier System for the Electron Microscope
Authors: Anderson K.
Published: June 2020

The possibilities of intensifying the light image produced on the fluorescent screen of the microscope have been known for some time. The first practical system was described by Kushnir etal (1958) who used a five stage cascade type image intensifier. More recently a system has been described by Sadashige 1958. This technique has been used to develope a system for the EM6G/EM6B electron microscope.

The system employed can be seen from the schematic diagram in Fig. 1. The intensifier tube is a 4 stage cascade “sandwich” type image intensifier. The output can either be viewed directly or by using the T. V. camera as shown in the diagram.
A New 1,000 kV Electron Microscope
Authors: Nishigaki M. , Katagiri S. , Kimura H. , Tadano B.
Published: June 2020

The high voltage electron microscope has many advantageous features in comparison with the ordinary electron microscope. They are a higher penetrating efficiency of the electron, low chromatic aberration, high accuracy of the selected area diffraction and so on. Thus, the high voltage electron microscope becomes an indispensable instrument for the metallurgical, polymer and biological specimen studies. The application of the instrument involves today not only basic research but routine survey in the various fields. Particularly for the latter purpose, the performance, maintenance and reliability of the microscope should be same as those of commercial ones. The authors completed a 500 kV electron microscope in 1964 and a 1,000 kV one in 1966 taking these points into consideration. The construction of our 1,000 kV electron microscope is described below.
Microscopic Examination of the Fracture Surface of Stress Corroded 4340 Steel
Authors: Danovich J. F. , Sipes W. A. , Smith J.
Published: June 2020

In the continuing effort to determine exactly how and why metals fail, it was decided to utilize the high magnification, resolution and depth of field of the electron microscopy to study the fracture surfaces of 4340 steel stock which had a standard melting and heat treatment history and on stock which had been vacuum melted prior to the standard heat treatment. Before breaking, these specimens were subjected to accelerated stress corrosion experiments in electrochemical cells.
Atomic Injection as a Contrasting Technique
Authors: Manley J. H.
Published: June 2020

Conventional heavy-atom shadow techniques are useful only in revealing surface details of a specimen because of the inability of the atoms to penetrate the surface. Adding another variable, the impinging energy, by electrical acceleration offers several advantages. Among these are the contrasting of internal features at depths controlled by the incident energy and diminution of graininess of supporting films by decreased surface mobility. The method is illustrated with selected biological specimens and organic films which have been injected with cesium in the energy range 10-1000 eV.
Ion Beam Etching of Biological Material in the Scanning Electron Microscope
Authors: Echlin Patrick , Kynaston David , Knights Paul M.
Published: June 2020

An ion source has been designed to operate in the chamber of the Stereoscan scanning electron microscope and provides facilities for etching specimens in situ. The source is a demountable cold cathode discharge type requiring only simple control.

The ion beam described above has been used to progressively etch away hard or resilient biological material. This is the first time that ion beam etching of botanical specimens has been followed inside the scanning microscope, and marks the beginning of a range of dynamic experiments using this form of instrumentation.